/** * \file ssl.h * * \brief SSL/TLS functions. */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef MBEDTLS_SSL_H #define MBEDTLS_SSL_H #include "mbedtls/private_access.h" #include "mbedtls/build_info.h" #include "mbedtls/bignum.h" #include "mbedtls/ecp.h" #include "mbedtls/ssl_ciphersuites.h" #if defined(MBEDTLS_X509_CRT_PARSE_C) #include "mbedtls/x509_crt.h" #include "mbedtls/x509_crl.h" #endif #if defined(MBEDTLS_DHM_C) #include "mbedtls/dhm.h" #endif /* Adding guard for MBEDTLS_ECDSA_C to ensure no compile errors due * to guards also being in ssl_srv.c and ssl_cli.c. There is a gap * in functionality that access to ecdh_ctx structure is needed for * MBEDTLS_ECDSA_C which does not seem correct. */ #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) #include "mbedtls/ecdh.h" #endif #if defined(MBEDTLS_HAVE_TIME) #include "mbedtls/platform_time.h" #endif #if defined(MBEDTLS_USE_PSA_CRYPTO) #include "psa/crypto.h" #endif /* MBEDTLS_USE_PSA_CRYPTO */ /* * SSL Error codes */ #define MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS -0x7000 /**< A cryptographic operation is in progress. Try again later. */ #define MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE -0x7080 /**< The requested feature is not available. */ #define MBEDTLS_ERR_SSL_BAD_INPUT_DATA -0x7100 /**< Bad input parameters to function. */ #define MBEDTLS_ERR_SSL_INVALID_MAC -0x7180 /**< Verification of the message MAC failed. */ #define MBEDTLS_ERR_SSL_INVALID_RECORD -0x7200 /**< An invalid SSL record was received. */ #define MBEDTLS_ERR_SSL_CONN_EOF -0x7280 /**< The connection indicated an EOF. */ #define MBEDTLS_ERR_SSL_DECODE_ERROR -0x7300 /**< A message could not be parsed due to a syntactic error. */ /* Error space gap */ #define MBEDTLS_ERR_SSL_NO_RNG -0x7400 /**< No RNG was provided to the SSL module. */ #define MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE -0x7480 /**< No client certification received from the client, but required by the authentication mode. */ #define MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION -0x7500 /**< Client received an extended server hello containing an unsupported extension */ #define MBEDTLS_ERR_SSL_NO_APPLICATION_PROTOCOL -0x7580 /**< No ALPN protocols supported that the client advertises */ #define MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED -0x7600 /**< The own private key or pre-shared key is not set, but needed. */ #define MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED -0x7680 /**< No CA Chain is set, but required to operate. */ #define MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE -0x7700 /**< An unexpected message was received from our peer. */ #define MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE -0x7780 /**< A fatal alert message was received from our peer. */ #define MBEDTLS_ERR_SSL_UNRECOGNIZED_NAME -0x7800 /**< No server could be identified matching the client's SNI. */ #define MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY -0x7880 /**< The peer notified us that the connection is going to be closed. */ /* Error space gap */ /* Error space gap */ #define MBEDTLS_ERR_SSL_BAD_CERTIFICATE -0x7A00 /**< Processing of the Certificate handshake message failed. */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ #define MBEDTLS_ERR_SSL_ALLOC_FAILED -0x7F00 /**< Memory allocation failed */ #define MBEDTLS_ERR_SSL_HW_ACCEL_FAILED -0x7F80 /**< Hardware acceleration function returned with error */ #define MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH -0x6F80 /**< Hardware acceleration function skipped / left alone data */ #define MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION -0x6E80 /**< Handshake protocol not within min/max boundaries */ #define MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE -0x6E00 /**< The handshake negotiation failed. */ #define MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED -0x6D80 /**< Session ticket has expired. */ #define MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH -0x6D00 /**< Public key type mismatch (eg, asked for RSA key exchange and presented EC key) */ #define MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY -0x6C80 /**< Unknown identity received (eg, PSK identity) */ #define MBEDTLS_ERR_SSL_INTERNAL_ERROR -0x6C00 /**< Internal error (eg, unexpected failure in lower-level module) */ #define MBEDTLS_ERR_SSL_COUNTER_WRAPPING -0x6B80 /**< A counter would wrap (eg, too many messages exchanged). */ #define MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO -0x6B00 /**< Unexpected message at ServerHello in renegotiation. */ #define MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED -0x6A80 /**< DTLS client must retry for hello verification */ #define MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL -0x6A00 /**< A buffer is too small to receive or write a message */ /* Error space gap */ #define MBEDTLS_ERR_SSL_WANT_READ -0x6900 /**< No data of requested type currently available on underlying transport. */ #define MBEDTLS_ERR_SSL_WANT_WRITE -0x6880 /**< Connection requires a write call. */ #define MBEDTLS_ERR_SSL_TIMEOUT -0x6800 /**< The operation timed out. */ #define MBEDTLS_ERR_SSL_CLIENT_RECONNECT -0x6780 /**< The client initiated a reconnect from the same port. */ #define MBEDTLS_ERR_SSL_UNEXPECTED_RECORD -0x6700 /**< Record header looks valid but is not expected. */ #define MBEDTLS_ERR_SSL_NON_FATAL -0x6680 /**< The alert message received indicates a non-fatal error. */ #define MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER -0x6600 /**< A field in a message was incorrect or inconsistent with other fields. */ #define MBEDTLS_ERR_SSL_CONTINUE_PROCESSING -0x6580 /**< Internal-only message signaling that further message-processing should be done */ #define MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS -0x6500 /**< The asynchronous operation is not completed yet. */ #define MBEDTLS_ERR_SSL_EARLY_MESSAGE -0x6480 /**< Internal-only message signaling that a message arrived early. */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ /* Error space gap */ #define MBEDTLS_ERR_SSL_UNEXPECTED_CID -0x6000 /**< An encrypted DTLS-frame with an unexpected CID was received. */ #define MBEDTLS_ERR_SSL_VERSION_MISMATCH -0x5F00 /**< An operation failed due to an unexpected version or configuration. */ #define MBEDTLS_ERR_SSL_BAD_CONFIG -0x5E80 /**< Invalid value in SSL config */ /* * Various constants */ /* These are the high an low bytes of ProtocolVersion as defined by: * - RFC 5246: ProtocolVersion version = { 3, 3 }; // TLS v1.2 * - RFC 8446: see section 4.2.1 */ #define MBEDTLS_SSL_MAJOR_VERSION_3 3 #define MBEDTLS_SSL_MINOR_VERSION_3 3 /*!< TLS v1.2 */ #define MBEDTLS_SSL_MINOR_VERSION_4 4 /*!< TLS v1.3 (experimental) */ #define MBEDTLS_SSL_TRANSPORT_STREAM 0 /*!< TLS */ #define MBEDTLS_SSL_TRANSPORT_DATAGRAM 1 /*!< DTLS */ #define MBEDTLS_SSL_MAX_HOST_NAME_LEN 255 /*!< Maximum host name defined in RFC 1035 */ #define MBEDTLS_SSL_MAX_ALPN_NAME_LEN 255 /*!< Maximum size in bytes of a protocol name in alpn ext., RFC 7301 */ #define MBEDTLS_SSL_MAX_ALPN_LIST_LEN 65535 /*!< Maximum size in bytes of list in alpn ext., RFC 7301 */ /* RFC 6066 section 4, see also mfl_code_to_length in ssl_tls.c * NONE must be zero so that memset()ing structure to zero works */ #define MBEDTLS_SSL_MAX_FRAG_LEN_NONE 0 /*!< don't use this extension */ #define MBEDTLS_SSL_MAX_FRAG_LEN_512 1 /*!< MaxFragmentLength 2^9 */ #define MBEDTLS_SSL_MAX_FRAG_LEN_1024 2 /*!< MaxFragmentLength 2^10 */ #define MBEDTLS_SSL_MAX_FRAG_LEN_2048 3 /*!< MaxFragmentLength 2^11 */ #define MBEDTLS_SSL_MAX_FRAG_LEN_4096 4 /*!< MaxFragmentLength 2^12 */ #define MBEDTLS_SSL_MAX_FRAG_LEN_INVALID 5 /*!< first invalid value */ #define MBEDTLS_SSL_IS_CLIENT 0 #define MBEDTLS_SSL_IS_SERVER 1 #define MBEDTLS_SSL_EXTENDED_MS_DISABLED 0 #define MBEDTLS_SSL_EXTENDED_MS_ENABLED 1 #define MBEDTLS_SSL_CID_DISABLED 0 #define MBEDTLS_SSL_CID_ENABLED 1 #define MBEDTLS_SSL_ETM_DISABLED 0 #define MBEDTLS_SSL_ETM_ENABLED 1 #define MBEDTLS_SSL_COMPRESS_NULL 0 #define MBEDTLS_SSL_VERIFY_NONE 0 #define MBEDTLS_SSL_VERIFY_OPTIONAL 1 #define MBEDTLS_SSL_VERIFY_REQUIRED 2 #define MBEDTLS_SSL_VERIFY_UNSET 3 /* Used only for sni_authmode */ #define MBEDTLS_SSL_LEGACY_RENEGOTIATION 0 #define MBEDTLS_SSL_SECURE_RENEGOTIATION 1 #define MBEDTLS_SSL_RENEGOTIATION_DISABLED 0 #define MBEDTLS_SSL_RENEGOTIATION_ENABLED 1 #define MBEDTLS_SSL_ANTI_REPLAY_DISABLED 0 #define MBEDTLS_SSL_ANTI_REPLAY_ENABLED 1 #define MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED -1 #define MBEDTLS_SSL_RENEGO_MAX_RECORDS_DEFAULT 16 #define MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION 0 #define MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION 1 #define MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE 2 #define MBEDTLS_SSL_TRUNC_HMAC_DISABLED 0 #define MBEDTLS_SSL_TRUNC_HMAC_ENABLED 1 #define MBEDTLS_SSL_TRUNCATED_HMAC_LEN 10 /* 80 bits, rfc 6066 section 7 */ #define MBEDTLS_SSL_SESSION_TICKETS_DISABLED 0 #define MBEDTLS_SSL_SESSION_TICKETS_ENABLED 1 #define MBEDTLS_SSL_PRESET_DEFAULT 0 #define MBEDTLS_SSL_PRESET_SUITEB 2 #define MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED 1 #define MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED 0 #define MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED 0 #define MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED 1 #define MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_CLIENT 1 #define MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_SERVER 0 /* * Default range for DTLS retransmission timer value, in milliseconds. * RFC 6347 4.2.4.1 says from 1 second to 60 seconds. */ #define MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MIN 1000 #define MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MAX 60000 /** * \name SECTION: Module settings * * The configuration options you can set for this module are in this section. * Either change them in mbedtls_config.h or define them on the compiler command line. * \{ */ /* * Maximum fragment length in bytes, * determines the size of each of the two internal I/O buffers. * * Note: the RFC defines the default size of SSL / TLS messages. If you * change the value here, other clients / servers may not be able to * communicate with you anymore. Only change this value if you control * both sides of the connection and have it reduced at both sides, or * if you're using the Max Fragment Length extension and you know all your * peers are using it too! */ #if !defined(MBEDTLS_SSL_IN_CONTENT_LEN) #define MBEDTLS_SSL_IN_CONTENT_LEN 16384 #endif #if !defined(MBEDTLS_SSL_OUT_CONTENT_LEN) #define MBEDTLS_SSL_OUT_CONTENT_LEN 16384 #endif /* * Maximum number of heap-allocated bytes for the purpose of * DTLS handshake message reassembly and future message buffering. */ #if !defined(MBEDTLS_SSL_DTLS_MAX_BUFFERING) #define MBEDTLS_SSL_DTLS_MAX_BUFFERING 32768 #endif /* * Maximum length of CIDs for incoming and outgoing messages. */ #if !defined(MBEDTLS_SSL_CID_IN_LEN_MAX) #define MBEDTLS_SSL_CID_IN_LEN_MAX 32 #endif #if !defined(MBEDTLS_SSL_CID_OUT_LEN_MAX) #define MBEDTLS_SSL_CID_OUT_LEN_MAX 32 #endif #if !defined(MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY) #define MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY 16 #endif /* \} name SECTION: Module settings */ /* * Length of the verify data for secure renegotiation */ #define MBEDTLS_SSL_VERIFY_DATA_MAX_LEN 12 /* * Signaling ciphersuite values (SCSV) */ #define MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO 0xFF /**< renegotiation info ext */ /* * Supported Signature and Hash algorithms (For TLS 1.2) * RFC 5246 section 7.4.1.4.1 */ #define MBEDTLS_SSL_HASH_NONE 0 #define MBEDTLS_SSL_HASH_MD5 1 #define MBEDTLS_SSL_HASH_SHA1 2 #define MBEDTLS_SSL_HASH_SHA224 3 #define MBEDTLS_SSL_HASH_SHA256 4 #define MBEDTLS_SSL_HASH_SHA384 5 #define MBEDTLS_SSL_HASH_SHA512 6 #define MBEDTLS_SSL_SIG_ANON 0 #define MBEDTLS_SSL_SIG_RSA 1 #define MBEDTLS_SSL_SIG_ECDSA 3 /* * Client Certificate Types * RFC 5246 section 7.4.4 plus RFC 4492 section 5.5 */ #define MBEDTLS_SSL_CERT_TYPE_RSA_SIGN 1 #define MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN 64 /* * Message, alert and handshake types */ #define MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC 20 #define MBEDTLS_SSL_MSG_ALERT 21 #define MBEDTLS_SSL_MSG_HANDSHAKE 22 #define MBEDTLS_SSL_MSG_APPLICATION_DATA 23 #define MBEDTLS_SSL_MSG_CID 25 #define MBEDTLS_SSL_ALERT_LEVEL_WARNING 1 #define MBEDTLS_SSL_ALERT_LEVEL_FATAL 2 #define MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY 0 /* 0x00 */ #define MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE 10 /* 0x0A */ #define MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC 20 /* 0x14 */ #define MBEDTLS_SSL_ALERT_MSG_DECRYPTION_FAILED 21 /* 0x15 */ #define MBEDTLS_SSL_ALERT_MSG_RECORD_OVERFLOW 22 /* 0x16 */ #define MBEDTLS_SSL_ALERT_MSG_DECOMPRESSION_FAILURE 30 /* 0x1E */ #define MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE 40 /* 0x28 */ #define MBEDTLS_SSL_ALERT_MSG_NO_CERT 41 /* 0x29 */ #define MBEDTLS_SSL_ALERT_MSG_BAD_CERT 42 /* 0x2A */ #define MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT 43 /* 0x2B */ #define MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED 44 /* 0x2C */ #define MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED 45 /* 0x2D */ #define MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN 46 /* 0x2E */ #define MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER 47 /* 0x2F */ #define MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA 48 /* 0x30 */ #define MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED 49 /* 0x31 */ #define MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR 50 /* 0x32 */ #define MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR 51 /* 0x33 */ #define MBEDTLS_SSL_ALERT_MSG_EXPORT_RESTRICTION 60 /* 0x3C */ #define MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION 70 /* 0x46 */ #define MBEDTLS_SSL_ALERT_MSG_INSUFFICIENT_SECURITY 71 /* 0x47 */ #define MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR 80 /* 0x50 */ #define MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK 86 /* 0x56 */ #define MBEDTLS_SSL_ALERT_MSG_USER_CANCELED 90 /* 0x5A */ #define MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION 100 /* 0x64 */ #define MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT 110 /* 0x6E */ #define MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME 112 /* 0x70 */ #define MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY 115 /* 0x73 */ #define MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL 120 /* 0x78 */ #define MBEDTLS_SSL_HS_HELLO_REQUEST 0 #define MBEDTLS_SSL_HS_CLIENT_HELLO 1 #define MBEDTLS_SSL_HS_SERVER_HELLO 2 #define MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST 3 #define MBEDTLS_SSL_HS_NEW_SESSION_TICKET 4 #define MBEDTLS_SSL_HS_CERTIFICATE 11 #define MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE 12 #define MBEDTLS_SSL_HS_CERTIFICATE_REQUEST 13 #define MBEDTLS_SSL_HS_SERVER_HELLO_DONE 14 #define MBEDTLS_SSL_HS_CERTIFICATE_VERIFY 15 #define MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE 16 #define MBEDTLS_SSL_HS_FINISHED 20 /* * TLS extensions */ #define MBEDTLS_TLS_EXT_SERVERNAME 0 #define MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME 0 #define MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH 1 #define MBEDTLS_TLS_EXT_TRUNCATED_HMAC 4 #define MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES 10 #define MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS 11 #define MBEDTLS_TLS_EXT_SIG_ALG 13 #define MBEDTLS_TLS_EXT_USE_SRTP 14 #define MBEDTLS_TLS_EXT_ALPN 16 #define MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC 22 /* 0x16 */ #define MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET 0x0017 /* 23 */ #define MBEDTLS_TLS_EXT_SESSION_TICKET 35 /* The value of the CID extension is still TBD as of * draft-ietf-tls-dtls-connection-id-05 * (https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05) */ #define MBEDTLS_TLS_EXT_CID 254 /* TBD */ #define MBEDTLS_TLS_EXT_ECJPAKE_KKPP 256 /* experimental */ #define MBEDTLS_TLS_EXT_RENEGOTIATION_INFO 0xFF01 /* * Size defines */ #if !defined(MBEDTLS_PSK_MAX_LEN) #define MBEDTLS_PSK_MAX_LEN 32 /* 256 bits */ #endif /* Dummy type used only for its size */ union mbedtls_ssl_premaster_secret { #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) unsigned char _pms_rsa[48]; /* RFC 5246 8.1.1 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) unsigned char _pms_dhm[MBEDTLS_MPI_MAX_SIZE]; /* RFC 5246 8.1.2 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) unsigned char _pms_ecdh[MBEDTLS_ECP_MAX_BYTES]; /* RFC 4492 5.10 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) unsigned char _pms_psk[4 + 2 * MBEDTLS_PSK_MAX_LEN]; /* RFC 4279 2 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) unsigned char _pms_dhe_psk[4 + MBEDTLS_MPI_MAX_SIZE + MBEDTLS_PSK_MAX_LEN]; /* RFC 4279 3 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) unsigned char _pms_rsa_psk[52 + MBEDTLS_PSK_MAX_LEN]; /* RFC 4279 4 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) unsigned char _pms_ecdhe_psk[4 + MBEDTLS_ECP_MAX_BYTES + MBEDTLS_PSK_MAX_LEN]; /* RFC 5489 2 */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) unsigned char _pms_ecjpake[32]; /* Thread spec: SHA-256 output */ #endif }; #define MBEDTLS_PREMASTER_SIZE sizeof( union mbedtls_ssl_premaster_secret ) #ifdef __cplusplus extern "C" { #endif /* * SSL state machine */ typedef enum { MBEDTLS_SSL_HELLO_REQUEST, MBEDTLS_SSL_CLIENT_HELLO, MBEDTLS_SSL_SERVER_HELLO, MBEDTLS_SSL_SERVER_CERTIFICATE, MBEDTLS_SSL_SERVER_KEY_EXCHANGE, MBEDTLS_SSL_CERTIFICATE_REQUEST, MBEDTLS_SSL_SERVER_HELLO_DONE, MBEDTLS_SSL_CLIENT_CERTIFICATE, MBEDTLS_SSL_CLIENT_KEY_EXCHANGE, MBEDTLS_SSL_CERTIFICATE_VERIFY, MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC, MBEDTLS_SSL_CLIENT_FINISHED, MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC, MBEDTLS_SSL_SERVER_FINISHED, MBEDTLS_SSL_FLUSH_BUFFERS, MBEDTLS_SSL_HANDSHAKE_WRAPUP, MBEDTLS_SSL_HANDSHAKE_OVER, MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET, MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT, } mbedtls_ssl_states; /** * \brief Callback type: send data on the network. * * \note That callback may be either blocking or non-blocking. * * \param ctx Context for the send callback (typically a file descriptor) * \param buf Buffer holding the data to send * \param len Length of the data to send * * \return The callback must return the number of bytes sent if any, * or a non-zero error code. * If performing non-blocking I/O, \c MBEDTLS_ERR_SSL_WANT_WRITE * must be returned when the operation would block. * * \note The callback is allowed to send fewer bytes than requested. * It must always return the number of bytes actually sent. */ typedef int mbedtls_ssl_send_t( void *ctx, const unsigned char *buf, size_t len ); /** * \brief Callback type: receive data from the network. * * \note That callback may be either blocking or non-blocking. * * \param ctx Context for the receive callback (typically a file * descriptor) * \param buf Buffer to write the received data to * \param len Length of the receive buffer * * \return The callback must return the number of bytes received, * or a non-zero error code. * If performing non-blocking I/O, \c MBEDTLS_ERR_SSL_WANT_READ * must be returned when the operation would block. * * \note The callback may receive fewer bytes than the length of the * buffer. It must always return the number of bytes actually * received and written to the buffer. */ typedef int mbedtls_ssl_recv_t( void *ctx, unsigned char *buf, size_t len ); /** * \brief Callback type: receive data from the network, with timeout * * \note That callback must block until data is received, or the * timeout delay expires, or the operation is interrupted by a * signal. * * \param ctx Context for the receive callback (typically a file descriptor) * \param buf Buffer to write the received data to * \param len Length of the receive buffer * \param timeout Maximum nomber of millisecondes to wait for data * 0 means no timeout (potentially waiting forever) * * \return The callback must return the number of bytes received, * or a non-zero error code: * \c MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out, * \c MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. * * \note The callback may receive fewer bytes than the length of the * buffer. It must always return the number of bytes actually * received and written to the buffer. */ typedef int mbedtls_ssl_recv_timeout_t( void *ctx, unsigned char *buf, size_t len, uint32_t timeout ); /** * \brief Callback type: set a pair of timers/delays to watch * * \param ctx Context pointer * \param int_ms Intermediate delay in milliseconds * \param fin_ms Final delay in milliseconds * 0 cancels the current timer. * * \note This callback must at least store the necessary information * for the associated \c mbedtls_ssl_get_timer_t callback to * return correct information. * * \note If using a event-driven style of programming, an event must * be generated when the final delay is passed. The event must * cause a call to \c mbedtls_ssl_handshake() with the proper * SSL context to be scheduled. Care must be taken to ensure * that at most one such call happens at a time. * * \note Only one timer at a time must be running. Calling this * function while a timer is running must cancel it. Cancelled * timers must not generate any event. */ typedef void mbedtls_ssl_set_timer_t( void * ctx, uint32_t int_ms, uint32_t fin_ms ); /** * \brief Callback type: get status of timers/delays * * \param ctx Context pointer * * \return This callback must return: * -1 if cancelled (fin_ms == 0), * 0 if none of the delays have passed, * 1 if only the intermediate delay has passed, * 2 if the final delay has passed. */ typedef int mbedtls_ssl_get_timer_t( void * ctx ); /* Defined below */ typedef struct mbedtls_ssl_session mbedtls_ssl_session; typedef struct mbedtls_ssl_context mbedtls_ssl_context; typedef struct mbedtls_ssl_config mbedtls_ssl_config; /* Defined in library/ssl_misc.h */ typedef struct mbedtls_ssl_transform mbedtls_ssl_transform; typedef struct mbedtls_ssl_handshake_params mbedtls_ssl_handshake_params; typedef struct mbedtls_ssl_sig_hash_set_t mbedtls_ssl_sig_hash_set_t; #if defined(MBEDTLS_X509_CRT_PARSE_C) typedef struct mbedtls_ssl_key_cert mbedtls_ssl_key_cert; #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) typedef struct mbedtls_ssl_flight_item mbedtls_ssl_flight_item; #endif /** * \brief Callback type: server-side session cache getter * * The session cache is logically a key value store, with * keys being session IDs and values being instances of * mbedtls_ssl_session. * * This callback retrieves an entry in this key-value store. * * \param data The address of the session cache structure to query. * \param session_id The buffer holding the session ID to query. * \param session_id_len The length of \p session_id in Bytes. * \param session The address of the session structure to populate. * It is initialized with mbdtls_ssl_session_init(), * and the callback must always leave it in a state * where it can safely be freed via * mbedtls_ssl_session_free() independent of the * return code of this function. * * \return \c 0 on success * \return A non-zero return value on failure. * */ typedef int mbedtls_ssl_cache_get_t( void *data, unsigned char const *session_id, size_t session_id_len, mbedtls_ssl_session *session ); /** * \brief Callback type: server-side session cache setter * * The session cache is logically a key value store, with * keys being session IDs and values being instances of * mbedtls_ssl_session. * * This callback sets an entry in this key-value store. * * \param data The address of the session cache structure to modify. * \param session_id The buffer holding the session ID to query. * \param session_id_len The length of \p session_id in Bytes. * \param session The address of the session to be stored in the * session cache. * * \return \c 0 on success * \return A non-zero return value on failure. */ typedef int mbedtls_ssl_cache_set_t( void *data, unsigned char const *session_id, size_t session_id_len, const mbedtls_ssl_session *session ); #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Callback type: start external signature operation. * * This callback is called during an SSL handshake to start * a signature decryption operation using an * external processor. The parameter \p cert contains * the public key; it is up to the callback function to * determine how to access the associated private key. * * This function typically sends or enqueues a request, and * does not wait for the operation to complete. This allows * the handshake step to be non-blocking. * * The parameters \p ssl and \p cert are guaranteed to remain * valid throughout the handshake. On the other hand, this * function must save the contents of \p hash if the value * is needed for later processing, because the \p hash buffer * is no longer valid after this function returns. * * This function may call mbedtls_ssl_set_async_operation_data() * to store an operation context for later retrieval * by the resume or cancel callback. * * \note For RSA signatures, this function must produce output * that is consistent with PKCS#1 v1.5 in the same way as * mbedtls_rsa_pkcs1_sign(). Before the private key operation, * apply the padding steps described in RFC 8017, section 9.2 * "EMSA-PKCS1-v1_5" as follows. * - If \p md_alg is #MBEDTLS_MD_NONE, apply the PKCS#1 v1.5 * encoding, treating \p hash as the DigestInfo to be * padded. In other words, apply EMSA-PKCS1-v1_5 starting * from step 3, with `T = hash` and `tLen = hash_len`. * - If `md_alg != MBEDTLS_MD_NONE`, apply the PKCS#1 v1.5 * encoding, treating \p hash as the hash to be encoded and * padded. In other words, apply EMSA-PKCS1-v1_5 starting * from step 2, with `digestAlgorithm` obtained by calling * mbedtls_oid_get_oid_by_md() on \p md_alg. * * \note For ECDSA signatures, the output format is the DER encoding * `Ecdsa-Sig-Value` defined in * [RFC 4492 section 5.4](https://tools.ietf.org/html/rfc4492#section-5.4). * * \param ssl The SSL connection instance. It should not be * modified other than via * mbedtls_ssl_set_async_operation_data(). * \param cert Certificate containing the public key. * In simple cases, this is one of the pointers passed to * mbedtls_ssl_conf_own_cert() when configuring the SSL * connection. However, if other callbacks are used, this * property may not hold. For example, if an SNI callback * is registered with mbedtls_ssl_conf_sni(), then * this callback determines what certificate is used. * \param md_alg Hash algorithm. * \param hash Buffer containing the hash. This buffer is * no longer valid when the function returns. * \param hash_len Size of the \c hash buffer in bytes. * * \return 0 if the operation was started successfully and the SSL * stack should call the resume callback immediately. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if the operation * was started successfully and the SSL stack should return * immediately without calling the resume callback yet. * \return #MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH if the external * processor does not support this key. The SSL stack will * use the private key object instead. * \return Any other error indicates a fatal failure and is * propagated up the call chain. The callback should * use \c MBEDTLS_ERR_PK_xxx error codes, and must not * use \c MBEDTLS_ERR_SSL_xxx error codes except as * directed in the documentation of this callback. */ typedef int mbedtls_ssl_async_sign_t( mbedtls_ssl_context *ssl, mbedtls_x509_crt *cert, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len ); /** * \brief Callback type: start external decryption operation. * * This callback is called during an SSL handshake to start * an RSA decryption operation using an * external processor. The parameter \p cert contains * the public key; it is up to the callback function to * determine how to access the associated private key. * * This function typically sends or enqueues a request, and * does not wait for the operation to complete. This allows * the handshake step to be non-blocking. * * The parameters \p ssl and \p cert are guaranteed to remain * valid throughout the handshake. On the other hand, this * function must save the contents of \p input if the value * is needed for later processing, because the \p input buffer * is no longer valid after this function returns. * * This function may call mbedtls_ssl_set_async_operation_data() * to store an operation context for later retrieval * by the resume or cancel callback. * * \warning RSA decryption as used in TLS is subject to a potential * timing side channel attack first discovered by Bleichenbacher * in 1998. This attack can be remotely exploitable * in practice. To avoid this attack, you must ensure that * if the callback performs an RSA decryption, the time it * takes to execute and return the result does not depend * on whether the RSA decryption succeeded or reported * invalid padding. * * \param ssl The SSL connection instance. It should not be * modified other than via * mbedtls_ssl_set_async_operation_data(). * \param cert Certificate containing the public key. * In simple cases, this is one of the pointers passed to * mbedtls_ssl_conf_own_cert() when configuring the SSL * connection. However, if other callbacks are used, this * property may not hold. For example, if an SNI callback * is registered with mbedtls_ssl_conf_sni(), then * this callback determines what certificate is used. * \param input Buffer containing the input ciphertext. This buffer * is no longer valid when the function returns. * \param input_len Size of the \p input buffer in bytes. * * \return 0 if the operation was started successfully and the SSL * stack should call the resume callback immediately. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if the operation * was started successfully and the SSL stack should return * immediately without calling the resume callback yet. * \return #MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH if the external * processor does not support this key. The SSL stack will * use the private key object instead. * \return Any other error indicates a fatal failure and is * propagated up the call chain. The callback should * use \c MBEDTLS_ERR_PK_xxx error codes, and must not * use \c MBEDTLS_ERR_SSL_xxx error codes except as * directed in the documentation of this callback. */ typedef int mbedtls_ssl_async_decrypt_t( mbedtls_ssl_context *ssl, mbedtls_x509_crt *cert, const unsigned char *input, size_t input_len ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ /** * \brief Callback type: resume external operation. * * This callback is called during an SSL handshake to resume * an external operation started by the * ::mbedtls_ssl_async_sign_t or * ::mbedtls_ssl_async_decrypt_t callback. * * This function typically checks the status of a pending * request or causes the request queue to make progress, and * does not wait for the operation to complete. This allows * the handshake step to be non-blocking. * * This function may call mbedtls_ssl_get_async_operation_data() * to retrieve an operation context set by the start callback. * It may call mbedtls_ssl_set_async_operation_data() to modify * this context. * * Note that when this function returns a status other than * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, it must free any * resources associated with the operation. * * \param ssl The SSL connection instance. It should not be * modified other than via * mbedtls_ssl_set_async_operation_data(). * \param output Buffer containing the output (signature or decrypted * data) on success. * \param output_len On success, number of bytes written to \p output. * \param output_size Size of the \p output buffer in bytes. * * \return 0 if output of the operation is available in the * \p output buffer. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if the operation * is still in progress. Subsequent requests for progress * on the SSL connection will call the resume callback * again. * \return Any other error means that the operation is aborted. * The SSL handshake is aborted. The callback should * use \c MBEDTLS_ERR_PK_xxx error codes, and must not * use \c MBEDTLS_ERR_SSL_xxx error codes except as * directed in the documentation of this callback. */ typedef int mbedtls_ssl_async_resume_t( mbedtls_ssl_context *ssl, unsigned char *output, size_t *output_len, size_t output_size ); /** * \brief Callback type: cancel external operation. * * This callback is called if an SSL connection is closed * while an asynchronous operation is in progress. Note that * this callback is not called if the * ::mbedtls_ssl_async_resume_t callback has run and has * returned a value other than * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, since in that case * the asynchronous operation has already completed. * * This function may call mbedtls_ssl_get_async_operation_data() * to retrieve an operation context set by the start callback. * * \param ssl The SSL connection instance. It should not be * modified. */ typedef void mbedtls_ssl_async_cancel_t( mbedtls_ssl_context *ssl ); #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && \ !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) #define MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN 48 #if defined(MBEDTLS_SHA256_C) #define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA256 #define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN 32 #elif defined(MBEDTLS_SHA384_C) #define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA384 #define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN 48 #elif defined(MBEDTLS_SHA1_C) #define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA1 #define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN 20 #else /* This is already checked in check_config.h, but be sure. */ #error "Bad configuration - need SHA-1, SHA-256 or SHA-512 enabled to compute digest of peer CRT." #endif #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #if defined(MBEDTLS_SSL_DTLS_SRTP) #define MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH 255 #define MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH 4 /* * For code readability use a typedef for DTLS-SRTP profiles * * Use_srtp extension protection profiles values as defined in * http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml * * Reminder: if this list is expanded mbedtls_ssl_check_srtp_profile_value * must be updated too. */ #define MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_80 ( (uint16_t) 0x0001) #define MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_32 ( (uint16_t) 0x0002) #define MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_80 ( (uint16_t) 0x0005) #define MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_32 ( (uint16_t) 0x0006) /* This one is not iana defined, but for code readability. */ #define MBEDTLS_TLS_SRTP_UNSET ( (uint16_t) 0x0000) typedef uint16_t mbedtls_ssl_srtp_profile; typedef struct mbedtls_dtls_srtp_info_t { /*! The SRTP profile that was negotiated. */ mbedtls_ssl_srtp_profile MBEDTLS_PRIVATE(chosen_dtls_srtp_profile); /*! The length of mki_value. */ uint16_t MBEDTLS_PRIVATE(mki_len); /*! The mki_value used, with max size of 256 bytes. */ unsigned char MBEDTLS_PRIVATE(mki_value)[MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH]; } mbedtls_dtls_srtp_info; #endif /* MBEDTLS_SSL_DTLS_SRTP */ /* * This structure is used for storing current session data. * * Note: when changing this definition, we need to check and update: * - in tests/suites/test_suite_ssl.function: * ssl_populate_session() and ssl_serialize_session_save_load() * - in library/ssl_tls.c: * mbedtls_ssl_session_init() and mbedtls_ssl_session_free() * mbedtls_ssl_session_save() and ssl_session_load() * ssl_session_copy() */ struct mbedtls_ssl_session { #if defined(MBEDTLS_HAVE_TIME) mbedtls_time_t MBEDTLS_PRIVATE(start); /*!< starting time */ #endif int MBEDTLS_PRIVATE(ciphersuite); /*!< chosen ciphersuite */ int MBEDTLS_PRIVATE(compression); /*!< chosen compression */ size_t MBEDTLS_PRIVATE(id_len); /*!< session id length */ unsigned char MBEDTLS_PRIVATE(id)[32]; /*!< session identifier */ unsigned char MBEDTLS_PRIVATE(master)[48]; /*!< the master secret */ unsigned char exported; #if defined(MBEDTLS_X509_CRT_PARSE_C) #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) mbedtls_x509_crt *MBEDTLS_PRIVATE(peer_cert); /*!< peer X.509 cert chain */ #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ /*! The digest of the peer's end-CRT. This must be kept to detect CRT * changes during renegotiation, mitigating the triple handshake attack. */ unsigned char *MBEDTLS_PRIVATE(peer_cert_digest); size_t MBEDTLS_PRIVATE(peer_cert_digest_len); mbedtls_md_type_t MBEDTLS_PRIVATE(peer_cert_digest_type); #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ uint32_t MBEDTLS_PRIVATE(verify_result); /*!< verification result */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) unsigned char *MBEDTLS_PRIVATE(ticket); /*!< RFC 5077 session ticket */ size_t MBEDTLS_PRIVATE(ticket_len); /*!< session ticket length */ uint32_t MBEDTLS_PRIVATE(ticket_lifetime); /*!< ticket lifetime hint */ #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) unsigned char MBEDTLS_PRIVATE(mfl_code); /*!< MaxFragmentLength negotiated by peer */ #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) int MBEDTLS_PRIVATE(encrypt_then_mac); /*!< flag for EtM activation */ #endif }; /* * Identifiers for PRFs used in various versions of TLS. */ typedef enum { MBEDTLS_SSL_TLS_PRF_NONE, MBEDTLS_SSL_TLS_PRF_SHA384, MBEDTLS_SSL_TLS_PRF_SHA256, MBEDTLS_SSL_HKDF_EXPAND_SHA384, MBEDTLS_SSL_HKDF_EXPAND_SHA256 } mbedtls_tls_prf_types; #if defined(MBEDTLS_SSL_EXPORT_KEYS) typedef enum { MBEDTLS_SSL_KEY_EXPORT_TLS12_MASTER_SECRET = 0, #if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_EARLY_SECRET, MBEDTLS_SSL_KEY_EXPORT_TLS13_EARLY_EXPORTER_SECRET, MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_HANDSHAKE_TRAFFIC_SECRET, MBEDTLS_SSL_KEY_EXPORT_TLS13_SERVER_HANDSHAKE_TRAFFIC_SECRET, MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_APPLICATION_TRAFFIC_SECRET, MBEDTLS_SSL_KEY_EXPORT_TLS13_SERVER_APPLICATION_TRAFFIC_SECRET, #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */ } mbedtls_ssl_key_export_type; /** * \brief Callback type: Export key alongside random values for * session identification, and PRF for * implementation of TLS key exporters. * * \param p_expkey Context for the callback. * \param type The type of the key that is being exported. * \param secret The address of the buffer holding the secret * that's being exporterd. * \param secret_len The length of \p secret in bytes. * \param client_random The client random bytes. * \param server_random The server random bytes. * \param tls_prf_type The identifier for the PRF used in the handshake * to which the key belongs. */ typedef void mbedtls_ssl_export_keys_t( void *p_expkey, mbedtls_ssl_key_export_type type, const unsigned char *secret, size_t secret_len, const unsigned char client_random[32], const unsigned char server_random[32], mbedtls_tls_prf_types tls_prf_type ); #endif /* MBEDTLS_SSL_EXPORT_KEYS */ /** * SSL/TLS configuration to be shared between mbedtls_ssl_context structures. */ struct mbedtls_ssl_config { /* Group items by size (largest first) to minimize padding overhead */ /* * Pointers */ /** Allowed ciphersuites for (D)TLS 1.2 (0-terminated) */ const int *MBEDTLS_PRIVATE(ciphersuite_list); /** Callback for printing debug output */ void (*MBEDTLS_PRIVATE(f_dbg))(void *, int, const char *, int, const char *); void *MBEDTLS_PRIVATE(p_dbg); /*!< context for the debug function */ /** Callback for getting (pseudo-)random numbers */ int (*MBEDTLS_PRIVATE(f_rng))(void *, unsigned char *, size_t); void *MBEDTLS_PRIVATE(p_rng); /*!< context for the RNG function */ /** Callback to retrieve a session from the cache */ mbedtls_ssl_cache_get_t *MBEDTLS_PRIVATE(f_get_cache); /** Callback to store a session into the cache */ mbedtls_ssl_cache_set_t *MBEDTLS_PRIVATE(f_set_cache); void *MBEDTLS_PRIVATE(p_cache); /*!< context for cache callbacks */ #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) /** Callback for setting cert according to SNI extension */ int (*MBEDTLS_PRIVATE(f_sni))(void *, mbedtls_ssl_context *, const unsigned char *, size_t); void *MBEDTLS_PRIVATE(p_sni); /*!< context for SNI callback */ #endif #if defined(MBEDTLS_X509_CRT_PARSE_C) /** Callback to customize X.509 certificate chain verification */ int (*MBEDTLS_PRIVATE(f_vrfy))(void *, mbedtls_x509_crt *, int, uint32_t *); void *MBEDTLS_PRIVATE(p_vrfy); /*!< context for X.509 verify calllback */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) /** Callback to retrieve PSK key from identity */ int (*MBEDTLS_PRIVATE(f_psk))(void *, mbedtls_ssl_context *, const unsigned char *, size_t); void *MBEDTLS_PRIVATE(p_psk); /*!< context for PSK callback */ #endif #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) /** Callback to create & write a cookie for ClientHello veirifcation */ int (*MBEDTLS_PRIVATE(f_cookie_write))( void *, unsigned char **, unsigned char *, const unsigned char *, size_t ); /** Callback to verify validity of a ClientHello cookie */ int (*MBEDTLS_PRIVATE(f_cookie_check))( void *, const unsigned char *, size_t, const unsigned char *, size_t ); void *MBEDTLS_PRIVATE(p_cookie); /*!< context for the cookie callbacks */ #endif #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_SRV_C) /** Callback to create & write a session ticket */ int (*MBEDTLS_PRIVATE(f_ticket_write))( void *, const mbedtls_ssl_session *, unsigned char *, const unsigned char *, size_t *, uint32_t * ); /** Callback to parse a session ticket into a session structure */ int (*MBEDTLS_PRIVATE(f_ticket_parse))( void *, mbedtls_ssl_session *, unsigned char *, size_t); void *MBEDTLS_PRIVATE(p_ticket); /*!< context for the ticket callbacks */ #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) size_t MBEDTLS_PRIVATE(cid_len); /*!< The length of CIDs for incoming DTLS records. */ #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_X509_CRT_PARSE_C) const mbedtls_x509_crt_profile *MBEDTLS_PRIVATE(cert_profile); /*!< verification profile */ mbedtls_ssl_key_cert *MBEDTLS_PRIVATE(key_cert); /*!< own certificate/key pair(s) */ mbedtls_x509_crt *MBEDTLS_PRIVATE(ca_chain); /*!< trusted CAs */ mbedtls_x509_crl *MBEDTLS_PRIVATE(ca_crl); /*!< trusted CAs CRLs */ #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) mbedtls_x509_crt_ca_cb_t MBEDTLS_PRIVATE(f_ca_cb); void *MBEDTLS_PRIVATE(p_ca_cb); #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) #if defined(MBEDTLS_X509_CRT_PARSE_C) mbedtls_ssl_async_sign_t *MBEDTLS_PRIVATE(f_async_sign_start); /*!< start asynchronous signature operation */ mbedtls_ssl_async_decrypt_t *MBEDTLS_PRIVATE(f_async_decrypt_start); /*!< start asynchronous decryption operation */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ mbedtls_ssl_async_resume_t *MBEDTLS_PRIVATE(f_async_resume); /*!< resume asynchronous operation */ mbedtls_ssl_async_cancel_t *MBEDTLS_PRIVATE(f_async_cancel); /*!< cancel asynchronous operation */ void *MBEDTLS_PRIVATE(p_async_config_data); /*!< Configuration data set by mbedtls_ssl_conf_async_private_cb(). */ #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) const int *MBEDTLS_PRIVATE(sig_hashes); /*!< allowed signature hashes */ #endif #if defined(MBEDTLS_ECP_C) const mbedtls_ecp_group_id *MBEDTLS_PRIVATE(curve_list); /*!< allowed curves */ #endif #if defined(MBEDTLS_DHM_C) mbedtls_mpi MBEDTLS_PRIVATE(dhm_P); /*!< prime modulus for DHM */ mbedtls_mpi MBEDTLS_PRIVATE(dhm_G); /*!< generator for DHM */ #endif #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) #if defined(MBEDTLS_USE_PSA_CRYPTO) psa_key_id_t MBEDTLS_PRIVATE(psk_opaque); /*!< PSA key slot holding opaque PSK. This field * should only be set via * mbedtls_ssl_conf_psk_opaque(). * If either no PSK or a raw PSK have been * configured, this has value \c 0. */ #endif /* MBEDTLS_USE_PSA_CRYPTO */ unsigned char *MBEDTLS_PRIVATE(psk); /*!< The raw pre-shared key. This field should * only be set via mbedtls_ssl_conf_psk(). * If either no PSK or an opaque PSK * have been configured, this has value NULL. */ size_t MBEDTLS_PRIVATE(psk_len); /*!< The length of the raw pre-shared key. * This field should only be set via * mbedtls_ssl_conf_psk(). * Its value is non-zero if and only if * \c psk is not \c NULL. */ unsigned char *MBEDTLS_PRIVATE(psk_identity); /*!< The PSK identity for PSK negotiation. * This field should only be set via * mbedtls_ssl_conf_psk(). * This is set if and only if either * \c psk or \c psk_opaque are set. */ size_t MBEDTLS_PRIVATE(psk_identity_len);/*!< The length of PSK identity. * This field should only be set via * mbedtls_ssl_conf_psk(). * Its value is non-zero if and only if * \c psk is not \c NULL or \c psk_opaque * is not \c 0. */ #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ #if defined(MBEDTLS_SSL_ALPN) const char **MBEDTLS_PRIVATE(alpn_list); /*!< ordered list of protocols */ #endif #if defined(MBEDTLS_SSL_DTLS_SRTP) /*! ordered list of supported srtp profile */ const mbedtls_ssl_srtp_profile *MBEDTLS_PRIVATE(dtls_srtp_profile_list); /*! number of supported profiles */ size_t MBEDTLS_PRIVATE(dtls_srtp_profile_list_len); #endif /* MBEDTLS_SSL_DTLS_SRTP */ /* * Numerical settings (int then char) */ uint32_t MBEDTLS_PRIVATE(read_timeout); /*!< timeout for mbedtls_ssl_read (ms) */ #if defined(MBEDTLS_SSL_PROTO_DTLS) uint32_t MBEDTLS_PRIVATE(hs_timeout_min); /*!< initial value of the handshake retransmission timeout (ms) */ uint32_t MBEDTLS_PRIVATE(hs_timeout_max); /*!< maximum value of the handshake retransmission timeout (ms) */ #endif #if defined(MBEDTLS_SSL_RENEGOTIATION) int MBEDTLS_PRIVATE(renego_max_records); /*!< grace period for renegotiation */ unsigned char MBEDTLS_PRIVATE(renego_period)[8]; /*!< value of the record counters that triggers renegotiation */ #endif unsigned int MBEDTLS_PRIVATE(badmac_limit); /*!< limit of records with a bad MAC */ #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C) unsigned int MBEDTLS_PRIVATE(dhm_min_bitlen); /*!< min. bit length of the DHM prime */ #endif unsigned char MBEDTLS_PRIVATE(max_major_ver); /*!< max. major version used */ unsigned char MBEDTLS_PRIVATE(max_minor_ver); /*!< max. minor version used */ unsigned char MBEDTLS_PRIVATE(min_major_ver); /*!< min. major version used */ unsigned char MBEDTLS_PRIVATE(min_minor_ver); /*!< min. minor version used */ /* * Flags (bitfields) */ unsigned int MBEDTLS_PRIVATE(endpoint) : 1; /*!< 0: client, 1: server */ unsigned int MBEDTLS_PRIVATE(transport) : 1; /*!< stream (TLS) or datagram (DTLS) */ unsigned int MBEDTLS_PRIVATE(authmode) : 2; /*!< MBEDTLS_SSL_VERIFY_XXX */ /* needed even with renego disabled for LEGACY_BREAK_HANDSHAKE */ unsigned int MBEDTLS_PRIVATE(allow_legacy_renegotiation) : 2 ; /*!< MBEDTLS_LEGACY_XXX */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) unsigned int MBEDTLS_PRIVATE(mfl_code) : 3; /*!< desired fragment length */ #endif #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) unsigned int MBEDTLS_PRIVATE(encrypt_then_mac) : 1 ; /*!< negotiate encrypt-then-mac? */ #endif #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) unsigned int MBEDTLS_PRIVATE(extended_ms) : 1; /*!< negotiate extended master secret? */ #endif #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) unsigned int MBEDTLS_PRIVATE(anti_replay) : 1; /*!< detect and prevent replay? */ #endif #if defined(MBEDTLS_SSL_RENEGOTIATION) unsigned int MBEDTLS_PRIVATE(disable_renegotiation) : 1; /*!< disable renegotiation? */ #endif #if defined(MBEDTLS_SSL_SESSION_TICKETS) unsigned int MBEDTLS_PRIVATE(session_tickets) : 1; /*!< use session tickets? */ #endif #if defined(MBEDTLS_SSL_SRV_C) unsigned int MBEDTLS_PRIVATE(cert_req_ca_list) : 1; /*!< enable sending CA list in Certificate Request messages? */ unsigned int respect_cli_pref : 1; /*!< pick the ciphersuite according to the client's preferences rather than ours */ #endif #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) unsigned int MBEDTLS_PRIVATE(ignore_unexpected_cid) : 1; /*!< Determines whether DTLS * record with unexpected CID * should lead to failure. */ #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_DTLS_SRTP) unsigned int MBEDTLS_PRIVATE(dtls_srtp_mki_support) : 1; /* support having mki_value in the use_srtp extension */ #endif }; struct mbedtls_ssl_context { const mbedtls_ssl_config *MBEDTLS_PRIVATE(conf); /*!< configuration information */ /* * Miscellaneous */ int MBEDTLS_PRIVATE(state); /*!< SSL handshake: current state */ #if defined(MBEDTLS_SSL_RENEGOTIATION) int MBEDTLS_PRIVATE(renego_status); /*!< Initial, in progress, pending? */ int MBEDTLS_PRIVATE(renego_records_seen); /*!< Records since renego request, or with DTLS, number of retransmissions of request if renego_max_records is < 0 */ #endif /* MBEDTLS_SSL_RENEGOTIATION */ int MBEDTLS_PRIVATE(major_ver); /*!< equal to MBEDTLS_SSL_MAJOR_VERSION_3 */ int MBEDTLS_PRIVATE(minor_ver); /*!< one of MBEDTLS_SSL_MINOR_VERSION_x macros */ unsigned MBEDTLS_PRIVATE(badmac_seen); /*!< records with a bad MAC received */ #if defined(MBEDTLS_X509_CRT_PARSE_C) /** Callback to customize X.509 certificate chain verification */ int (*MBEDTLS_PRIVATE(f_vrfy))(void *, mbedtls_x509_crt *, int, uint32_t *); void *MBEDTLS_PRIVATE(p_vrfy); /*!< context for X.509 verify callback */ #endif mbedtls_ssl_send_t *MBEDTLS_PRIVATE(f_send); /*!< Callback for network send */ mbedtls_ssl_recv_t *MBEDTLS_PRIVATE(f_recv); /*!< Callback for network receive */ mbedtls_ssl_recv_timeout_t *MBEDTLS_PRIVATE(f_recv_timeout); /*!< Callback for network receive with timeout */ void *MBEDTLS_PRIVATE(p_bio); /*!< context for I/O operations */ /* * Session layer */ mbedtls_ssl_session *MBEDTLS_PRIVATE(session_in); /*!< current session data (in) */ mbedtls_ssl_session *MBEDTLS_PRIVATE(session_out); /*!< current session data (out) */ mbedtls_ssl_session *MBEDTLS_PRIVATE(session); /*!< negotiated session data */ mbedtls_ssl_session *MBEDTLS_PRIVATE(session_negotiate); /*!< session data in negotiation */ mbedtls_ssl_handshake_params *MBEDTLS_PRIVATE(handshake); /*!< params required only during the handshake process */ /* * Record layer transformations */ mbedtls_ssl_transform *MBEDTLS_PRIVATE(transform_in); /*!< current transform params (in) */ mbedtls_ssl_transform *MBEDTLS_PRIVATE(transform_out); /*!< current transform params (in) */ mbedtls_ssl_transform *MBEDTLS_PRIVATE(transform); /*!< negotiated transform params */ mbedtls_ssl_transform *MBEDTLS_PRIVATE(transform_negotiate); /*!< transform params in negotiation */ /* * Timers */ void *MBEDTLS_PRIVATE(p_timer); /*!< context for the timer callbacks */ mbedtls_ssl_set_timer_t *MBEDTLS_PRIVATE(f_set_timer); /*!< set timer callback */ mbedtls_ssl_get_timer_t *MBEDTLS_PRIVATE(f_get_timer); /*!< get timer callback */ /* * Record layer (incoming data) */ unsigned char *MBEDTLS_PRIVATE(in_buf); /*!< input buffer */ unsigned char *MBEDTLS_PRIVATE(in_ctr); /*!< 64-bit incoming message counter TLS: maintained by us DTLS: read from peer */ unsigned char *MBEDTLS_PRIVATE(in_hdr); /*!< start of record header */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) unsigned char *MBEDTLS_PRIVATE(in_cid); /*!< The start of the CID; * (the end is marked by in_len). */ #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ unsigned char *MBEDTLS_PRIVATE(in_len); /*!< two-bytes message length field */ unsigned char *MBEDTLS_PRIVATE(in_iv); /*!< ivlen-byte IV */ unsigned char *MBEDTLS_PRIVATE(in_msg); /*!< message contents (in_iv+ivlen) */ unsigned char *MBEDTLS_PRIVATE(in_offt); /*!< read offset in application data */ int MBEDTLS_PRIVATE(in_msgtype); /*!< record header: message type */ size_t MBEDTLS_PRIVATE(in_msglen); /*!< record header: message length */ size_t MBEDTLS_PRIVATE(in_left); /*!< amount of data read so far */ #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) size_t MBEDTLS_PRIVATE(in_buf_len); /*!< length of input buffer */ #endif #if defined(MBEDTLS_SSL_PROTO_DTLS) uint16_t MBEDTLS_PRIVATE(in_epoch); /*!< DTLS epoch for incoming records */ size_t MBEDTLS_PRIVATE(next_record_offset); /*!< offset of the next record in datagram (equal to in_left if none) */ #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) uint64_t MBEDTLS_PRIVATE(in_window_top); /*!< last validated record seq_num */ uint64_t MBEDTLS_PRIVATE(in_window); /*!< bitmask for replay detection */ #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ size_t MBEDTLS_PRIVATE(in_hslen); /*!< current handshake message length, including the handshake header */ int MBEDTLS_PRIVATE(nb_zero); /*!< # of 0-length encrypted messages */ int MBEDTLS_PRIVATE(keep_current_message); /*!< drop or reuse current message on next call to record layer? */ #if defined(MBEDTLS_SSL_PROTO_DTLS) uint8_t MBEDTLS_PRIVATE(disable_datagram_packing); /*!< Disable packing multiple records * within a single datagram. */ #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* * Record layer (outgoing data) */ unsigned char *MBEDTLS_PRIVATE(out_buf); /*!< output buffer */ unsigned char *MBEDTLS_PRIVATE(out_ctr); /*!< 64-bit outgoing message counter */ unsigned char *MBEDTLS_PRIVATE(out_hdr); /*!< start of record header */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) unsigned char *MBEDTLS_PRIVATE(out_cid); /*!< The start of the CID; * (the end is marked by in_len). */ #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ unsigned char *MBEDTLS_PRIVATE(out_len); /*!< two-bytes message length field */ unsigned char *MBEDTLS_PRIVATE(out_iv); /*!< ivlen-byte IV */ unsigned char *MBEDTLS_PRIVATE(out_msg); /*!< message contents (out_iv+ivlen) */ int MBEDTLS_PRIVATE(out_msgtype); /*!< record header: message type */ size_t MBEDTLS_PRIVATE(out_msglen); /*!< record header: message length */ size_t MBEDTLS_PRIVATE(out_left); /*!< amount of data not yet written */ #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) size_t MBEDTLS_PRIVATE(out_buf_len); /*!< length of output buffer */ #endif unsigned char MBEDTLS_PRIVATE(cur_out_ctr)[8]; /*!< Outgoing record sequence number. */ #if defined(MBEDTLS_SSL_PROTO_DTLS) uint16_t MBEDTLS_PRIVATE(mtu); /*!< path mtu, used to fragment outgoing messages */ #endif /* MBEDTLS_SSL_PROTO_DTLS */ /* * PKI layer */ int MBEDTLS_PRIVATE(client_auth); /*!< flag for client auth. */ /* * User settings */ #if defined(MBEDTLS_X509_CRT_PARSE_C) char *MBEDTLS_PRIVATE(hostname); /*!< expected peer CN for verification (and SNI if available) */ #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_ALPN) const char *MBEDTLS_PRIVATE(alpn_chosen); /*!< negotiated protocol */ #endif /* MBEDTLS_SSL_ALPN */ #if defined(MBEDTLS_SSL_DTLS_SRTP) /* * use_srtp extension */ mbedtls_dtls_srtp_info MBEDTLS_PRIVATE(dtls_srtp_info); #endif /* MBEDTLS_SSL_DTLS_SRTP */ /* * Information for DTLS hello verify */ #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) unsigned char *MBEDTLS_PRIVATE(cli_id); /*!< transport-level ID of the client */ size_t MBEDTLS_PRIVATE(cli_id_len); /*!< length of cli_id */ #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY && MBEDTLS_SSL_SRV_C */ /* * Secure renegotiation */ /* needed to know when to send extension on server */ int MBEDTLS_PRIVATE(secure_renegotiation); /*!< does peer support legacy or secure renegotiation */ #if defined(MBEDTLS_SSL_RENEGOTIATION) size_t MBEDTLS_PRIVATE(verify_data_len); /*!< length of verify data stored */ char MBEDTLS_PRIVATE(own_verify_data)[MBEDTLS_SSL_VERIFY_DATA_MAX_LEN]; /*!< previous handshake verify data */ char MBEDTLS_PRIVATE(peer_verify_data)[MBEDTLS_SSL_VERIFY_DATA_MAX_LEN]; /*!< previous handshake verify data */ #endif /* MBEDTLS_SSL_RENEGOTIATION */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) /* CID configuration to use in subsequent handshakes. */ /*! The next incoming CID, chosen by the user and applying to * all subsequent handshakes. This may be different from the * CID currently used in case the user has re-configured the CID * after an initial handshake. */ unsigned char MBEDTLS_PRIVATE(own_cid)[ MBEDTLS_SSL_CID_IN_LEN_MAX ]; uint8_t MBEDTLS_PRIVATE(own_cid_len); /*!< The length of \c own_cid. */ uint8_t MBEDTLS_PRIVATE(negotiate_cid); /*!< This indicates whether the CID extension should * be negotiated in the next handshake or not. * Possible values are #MBEDTLS_SSL_CID_ENABLED * and #MBEDTLS_SSL_CID_DISABLED. */ #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_EXPORT_KEYS) /** Callback to export key block and master secret */ mbedtls_ssl_export_keys_t *MBEDTLS_PRIVATE(f_export_keys); void *MBEDTLS_PRIVATE(p_export_keys); /*!< context for key export callback */ #endif }; /** * \brief Return the name of the ciphersuite associated with the * given ID * * \param ciphersuite_id SSL ciphersuite ID * * \return a string containing the ciphersuite name */ const char *mbedtls_ssl_get_ciphersuite_name( const int ciphersuite_id ); /** * \brief Return the ID of the ciphersuite associated with the * given name * * \param ciphersuite_name SSL ciphersuite name * * \return the ID with the ciphersuite or 0 if not found */ int mbedtls_ssl_get_ciphersuite_id( const char *ciphersuite_name ); /** * \brief Initialize an SSL context * Just makes the context ready for mbedtls_ssl_setup() or * mbedtls_ssl_free() * * \param ssl SSL context */ void mbedtls_ssl_init( mbedtls_ssl_context *ssl ); /** * \brief Set up an SSL context for use * * \note No copy of the configuration context is made, it can be * shared by many mbedtls_ssl_context structures. * * \warning The conf structure will be accessed during the session. * It must not be modified or freed as long as the session * is active. * * \warning This function must be called exactly once per context. * Calling mbedtls_ssl_setup again is not supported, even * if no session is active. * * \param ssl SSL context * \param conf SSL configuration to use * * \return 0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED if * memory allocation failed */ int mbedtls_ssl_setup( mbedtls_ssl_context *ssl, const mbedtls_ssl_config *conf ); /** * \brief Reset an already initialized SSL context for re-use * while retaining application-set variables, function * pointers and data. * * \param ssl SSL context * \return 0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED or MBEDTLS_ERR_SSL_HW_ACCEL_FAILED */ int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl ); /** * \brief Set the current endpoint type * * \param conf SSL configuration * \param endpoint must be MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER */ void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint ); /** * \brief Set the transport type (TLS or DTLS). * Default: TLS * * \note For DTLS, you must either provide a recv callback that * doesn't block, or one that handles timeouts, see * \c mbedtls_ssl_set_bio(). You also need to provide timer * callbacks with \c mbedtls_ssl_set_timer_cb(). * * \param conf SSL configuration * \param transport transport type: * MBEDTLS_SSL_TRANSPORT_STREAM for TLS, * MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS. */ void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport ); /** * \brief Set the certificate verification mode * Default: NONE on server, REQUIRED on client * * \param conf SSL configuration * \param authmode can be: * * MBEDTLS_SSL_VERIFY_NONE: peer certificate is not checked * (default on server) * (insecure on client) * * MBEDTLS_SSL_VERIFY_OPTIONAL: peer certificate is checked, however the * handshake continues even if verification failed; * mbedtls_ssl_get_verify_result() can be called after the * handshake is complete. * * MBEDTLS_SSL_VERIFY_REQUIRED: peer *must* present a valid certificate, * handshake is aborted if verification failed. * (default on client) * * \note On client, MBEDTLS_SSL_VERIFY_REQUIRED is the recommended mode. * With MBEDTLS_SSL_VERIFY_OPTIONAL, the user needs to call mbedtls_ssl_get_verify_result() at * the right time(s), which may not be obvious, while REQUIRED always perform * the verification as soon as possible. For example, REQUIRED was protecting * against the "triple handshake" attack even before it was found. */ void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode ); #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Set the verification callback (Optional). * * If set, the provided verify callback is called for each * certificate in the peer's CRT chain, including the trusted * root. For more information, please see the documentation of * \c mbedtls_x509_crt_verify(). * * \note For per context callbacks and contexts, please use * mbedtls_ssl_set_verify() instead. * * \param conf The SSL configuration to use. * \param f_vrfy The verification callback to use during CRT verification. * \param p_vrfy The opaque context to be passed to the callback. */ void mbedtls_ssl_conf_verify( mbedtls_ssl_config *conf, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ /** * \brief Set the random number generator callback * * \param conf SSL configuration * \param f_rng RNG function (mandatory) * \param p_rng RNG parameter */ void mbedtls_ssl_conf_rng( mbedtls_ssl_config *conf, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); /** * \brief Set the debug callback * * The callback has the following argument: * void * opaque context for the callback * int debug level * const char * file name * int line number * const char * message * * \param conf SSL configuration * \param f_dbg debug function * \param p_dbg debug parameter */ void mbedtls_ssl_conf_dbg( mbedtls_ssl_config *conf, void (*f_dbg)(void *, int, const char *, int, const char *), void *p_dbg ); /** * \brief Set the underlying BIO callbacks for write, read and * read-with-timeout. * * \param ssl SSL context * \param p_bio parameter (context) shared by BIO callbacks * \param f_send write callback * \param f_recv read callback * \param f_recv_timeout blocking read callback with timeout. * * \note One of f_recv or f_recv_timeout can be NULL, in which case * the other is used. If both are non-NULL, f_recv_timeout is * used and f_recv is ignored (as if it were NULL). * * \note The two most common use cases are: * - non-blocking I/O, f_recv != NULL, f_recv_timeout == NULL * - blocking I/O, f_recv == NULL, f_recv_timout != NULL * * \note For DTLS, you need to provide either a non-NULL * f_recv_timeout callback, or a f_recv that doesn't block. * * \note See the documentations of \c mbedtls_ssl_send_t, * \c mbedtls_ssl_recv_t and \c mbedtls_ssl_recv_timeout_t for * the conventions those callbacks must follow. * * \note On some platforms, net_sockets.c provides * \c mbedtls_net_send(), \c mbedtls_net_recv() and * \c mbedtls_net_recv_timeout() that are suitable to be used * here. */ void mbedtls_ssl_set_bio( mbedtls_ssl_context *ssl, void *p_bio, mbedtls_ssl_send_t *f_send, mbedtls_ssl_recv_t *f_recv, mbedtls_ssl_recv_timeout_t *f_recv_timeout ); #if defined(MBEDTLS_SSL_PROTO_DTLS) #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) /** * \brief Configure the use of the Connection ID (CID) * extension in the next handshake. * * Reference: draft-ietf-tls-dtls-connection-id-05 * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05 * * The DTLS CID extension allows the reliable association of * DTLS records to DTLS connections across changes in the * underlying transport (changed IP and Port metadata) by * adding explicit connection identifiers (CIDs) to the * headers of encrypted DTLS records. The desired CIDs are * configured by the application layer and are exchanged in * new `ClientHello` / `ServerHello` extensions during the * handshake, where each side indicates the CID it wants the * peer to use when writing encrypted messages. The CIDs are * put to use once records get encrypted: the stack discards * any incoming records that don't include the configured CID * in their header, and adds the peer's requested CID to the * headers of outgoing messages. * * This API enables or disables the use of the CID extension * in the next handshake and sets the value of the CID to * be used for incoming messages. * * \param ssl The SSL context to configure. This must be initialized. * \param enable This value determines whether the CID extension should * be used or not. Possible values are: * - MBEDTLS_SSL_CID_ENABLED to enable the use of the CID. * - MBEDTLS_SSL_CID_DISABLED (default) to disable the use * of the CID. * \param own_cid The address of the readable buffer holding the CID we want * the peer to use when sending encrypted messages to us. * This may be \c NULL if \p own_cid_len is \c 0. * This parameter is unused if \p enabled is set to * MBEDTLS_SSL_CID_DISABLED. * \param own_cid_len The length of \p own_cid. * This parameter is unused if \p enabled is set to * MBEDTLS_SSL_CID_DISABLED. * * \note The value of \p own_cid_len must match the value of the * \c len parameter passed to mbedtls_ssl_conf_cid() * when configuring the ::mbedtls_ssl_config that \p ssl * is bound to. * * \note This CID configuration applies to subsequent handshakes * performed on the SSL context \p ssl, but does not trigger * one. You still have to call `mbedtls_ssl_handshake()` * (for the initial handshake) or `mbedtls_ssl_renegotiate()` * (for a renegotiation handshake) explicitly after a * successful call to this function to run the handshake. * * \note This call cannot guarantee that the use of the CID * will be successfully negotiated in the next handshake, * because the peer might not support it. Specifically: * - On the Client, enabling the use of the CID through * this call implies that the `ClientHello` in the next * handshake will include the CID extension, thereby * offering the use of the CID to the server. Only if * the `ServerHello` contains the CID extension, too, * the CID extension will actually be put to use. * - On the Server, enabling the use of the CID through * this call implies that that the server will look for * the CID extension in a `ClientHello` from the client, * and, if present, reply with a CID extension in its * `ServerHello`. * * \note To check whether the use of the CID was negotiated * after the subsequent handshake has completed, please * use the API mbedtls_ssl_get_peer_cid(). * * \warning If the use of the CID extension is enabled in this call * and the subsequent handshake negotiates its use, Mbed TLS * will silently drop every packet whose CID does not match * the CID configured in \p own_cid. It is the responsibility * of the user to adapt the underlying transport to take care * of CID-based demultiplexing before handing datagrams to * Mbed TLS. * * \return \c 0 on success. In this case, the CID configuration * applies to the next handshake. * \return A negative error code on failure. */ int mbedtls_ssl_set_cid( mbedtls_ssl_context *ssl, int enable, unsigned char const *own_cid, size_t own_cid_len ); /** * \brief Get information about the use of the CID extension * in the current connection. * * \param ssl The SSL context to query. * \param enabled The address at which to store whether the CID extension * is currently in use or not. If the CID is in use, * `*enabled` is set to MBEDTLS_SSL_CID_ENABLED; * otherwise, it is set to MBEDTLS_SSL_CID_DISABLED. * \param peer_cid The address of the buffer in which to store the CID * chosen by the peer (if the CID extension is used). * This may be \c NULL in case the value of peer CID * isn't needed. If it is not \c NULL, \p peer_cid_len * must not be \c NULL. * \param peer_cid_len The address at which to store the size of the CID * chosen by the peer (if the CID extension is used). * This is also the number of Bytes in \p peer_cid that * have been written. * This may be \c NULL in case the length of the peer CID * isn't needed. If it is \c NULL, \p peer_cid must be * \c NULL, too. * * \note This applies to the state of the CID negotiated in * the last complete handshake. If a handshake is in * progress, this function will attempt to complete * the handshake first. * * \note If CID extensions have been exchanged but both client * and server chose to use an empty CID, this function * sets `*enabled` to #MBEDTLS_SSL_CID_DISABLED * (the rationale for this is that the resulting * communication is the same as if the CID extensions * hadn't been used). * * \return \c 0 on success. * \return A negative error code on failure. */ int mbedtls_ssl_get_peer_cid( mbedtls_ssl_context *ssl, int *enabled, unsigned char peer_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ], size_t *peer_cid_len ); #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ /** * \brief Set the Maximum Tranport Unit (MTU). * Special value: 0 means unset (no limit). * This represents the maximum size of a datagram payload * handled by the transport layer (usually UDP) as determined * by the network link and stack. In practice, this controls * the maximum size datagram the DTLS layer will pass to the * \c f_send() callback set using \c mbedtls_ssl_set_bio(). * * \note The limit on datagram size is converted to a limit on * record payload by subtracting the current overhead of * encapsulation and encryption/authentication if any. * * \note This can be called at any point during the connection, for * example when a Path Maximum Transfer Unit (PMTU) * estimate becomes available from other sources, * such as lower (or higher) protocol layers. * * \note This setting only controls the size of the packets we send, * and does not restrict the size of the datagrams we're * willing to receive. Client-side, you can request the * server to use smaller records with \c * mbedtls_ssl_conf_max_frag_len(). * * \note If both a MTU and a maximum fragment length have been * configured (or negotiated with the peer), the resulting * lower limit on record payload (see first note) is used. * * \note This can only be used to decrease the maximum size * of datagrams (hence records, see first note) sent. It * cannot be used to increase the maximum size of records over * the limit set by #MBEDTLS_SSL_OUT_CONTENT_LEN. * * \note Values lower than the current record layer expansion will * result in an error when trying to send data. * * \param ssl SSL context * \param mtu Value of the path MTU in bytes */ void mbedtls_ssl_set_mtu( mbedtls_ssl_context *ssl, uint16_t mtu ); #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Set a connection-specific verification callback (optional). * * If set, the provided verify callback is called for each * certificate in the peer's CRT chain, including the trusted * root. For more information, please see the documentation of * \c mbedtls_x509_crt_verify(). * * \note This call is analogous to mbedtls_ssl_conf_verify() but * binds the verification callback and context to an SSL context * as opposed to an SSL configuration. * If mbedtls_ssl_conf_verify() and mbedtls_ssl_set_verify() * are both used, mbedtls_ssl_set_verify() takes precedence. * * \param ssl The SSL context to use. * \param f_vrfy The verification callback to use during CRT verification. * \param p_vrfy The opaque context to be passed to the callback. */ void mbedtls_ssl_set_verify( mbedtls_ssl_context *ssl, int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *), void *p_vrfy ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ /** * \brief Set the timeout period for mbedtls_ssl_read() * (Default: no timeout.) * * \param conf SSL configuration context * \param timeout Timeout value in milliseconds. * Use 0 for no timeout (default). * * \note With blocking I/O, this will only work if a non-NULL * \c f_recv_timeout was set with \c mbedtls_ssl_set_bio(). * With non-blocking I/O, this will only work if timer * callbacks were set with \c mbedtls_ssl_set_timer_cb(). * * \note With non-blocking I/O, you may also skip this function * altogether and handle timeouts at the application layer. */ void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout ); /** * \brief Check whether a buffer contains a valid and authentic record * that has not been seen before. (DTLS only). * * This function does not change the user-visible state * of the SSL context. Its sole purpose is to provide * an indication of the legitimacy of an incoming record. * * This can be useful e.g. in distributed server environments * using the DTLS Connection ID feature, in which connections * might need to be passed between service instances on a change * of peer address, but where such disruptive operations should * only happen after the validity of incoming records has been * confirmed. * * \param ssl The SSL context to use. * \param buf The address of the buffer holding the record to be checked. * This must be a read/write buffer of length \p buflen Bytes. * \param buflen The length of \p buf in Bytes. * * \note This routine only checks whether the provided buffer begins * with a valid and authentic record that has not been seen * before, but does not check potential data following the * initial record. In particular, it is possible to pass DTLS * datagrams containing multiple records, in which case only * the first record is checked. * * \note This function modifies the input buffer \p buf. If you need * to preserve the original record, you have to maintain a copy. * * \return \c 0 if the record is valid and authentic and has not been * seen before. * \return MBEDTLS_ERR_SSL_INVALID_MAC if the check completed * successfully but the record was found to be not authentic. * \return MBEDTLS_ERR_SSL_INVALID_RECORD if the check completed * successfully but the record was found to be invalid for * a reason different from authenticity checking. * \return MBEDTLS_ERR_SSL_UNEXPECTED_RECORD if the check completed * successfully but the record was found to be unexpected * in the state of the SSL context, including replayed records. * \return Another negative error code on different kinds of failure. * In this case, the SSL context becomes unusable and needs * to be freed or reset before reuse. */ int mbedtls_ssl_check_record( mbedtls_ssl_context const *ssl, unsigned char *buf, size_t buflen ); /** * \brief Set the timer callbacks (Mandatory for DTLS.) * * \param ssl SSL context * \param p_timer parameter (context) shared by timer callbacks * \param f_set_timer set timer callback * \param f_get_timer get timer callback. Must return: * * \note See the documentation of \c mbedtls_ssl_set_timer_t and * \c mbedtls_ssl_get_timer_t for the conventions this pair of * callbacks must follow. * * \note On some platforms, timing.c provides * \c mbedtls_timing_set_delay() and * \c mbedtls_timing_get_delay() that are suitable for using * here, except if using an event-driven style. * * \note See also the "DTLS tutorial" article in our knowledge base. * https://tls.mbed.org/kb/how-to/dtls-tutorial */ void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl, void *p_timer, mbedtls_ssl_set_timer_t *f_set_timer, mbedtls_ssl_get_timer_t *f_get_timer ); /** * \brief Callback type: generate and write session ticket * * \note This describes what a callback implementation should do. * This callback should generate an encrypted and * authenticated ticket for the session and write it to the * output buffer. Here, ticket means the opaque ticket part * of the NewSessionTicket structure of RFC 5077. * * \param p_ticket Context for the callback * \param session SSL session to be written in the ticket * \param start Start of the output buffer * \param end End of the output buffer * \param tlen On exit, holds the length written * \param lifetime On exit, holds the lifetime of the ticket in seconds * * \return 0 if successful, or * a specific MBEDTLS_ERR_XXX code. */ typedef int mbedtls_ssl_ticket_write_t( void *p_ticket, const mbedtls_ssl_session *session, unsigned char *start, const unsigned char *end, size_t *tlen, uint32_t *lifetime ); /** * \brief Callback type: parse and load session ticket * * \note This describes what a callback implementation should do. * This callback should parse a session ticket as generated * by the corresponding mbedtls_ssl_ticket_write_t function, * and, if the ticket is authentic and valid, load the * session. * * \note The implementation is allowed to modify the first len * bytes of the input buffer, eg to use it as a temporary * area for the decrypted ticket contents. * * \param p_ticket Context for the callback * \param session SSL session to be loaded * \param buf Start of the buffer containing the ticket * \param len Length of the ticket. * * \return 0 if successful, or * MBEDTLS_ERR_SSL_INVALID_MAC if not authentic, or * MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED if expired, or * any other non-zero code for other failures. */ typedef int mbedtls_ssl_ticket_parse_t( void *p_ticket, mbedtls_ssl_session *session, unsigned char *buf, size_t len ); #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_SRV_C) /** * \brief Configure SSL session ticket callbacks (server only). * (Default: none.) * * \note On server, session tickets are enabled by providing * non-NULL callbacks. * * \note On client, use \c mbedtls_ssl_conf_session_tickets(). * * \param conf SSL configuration context * \param f_ticket_write Callback for writing a ticket * \param f_ticket_parse Callback for parsing a ticket * \param p_ticket Context shared by the two callbacks */ void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf, mbedtls_ssl_ticket_write_t *f_ticket_write, mbedtls_ssl_ticket_parse_t *f_ticket_parse, void *p_ticket ); #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_EXPORT_KEYS) /** * \brief Configure a key export callback. * (Default: none.) * * This API can be used for two purposes: * - Debugging: Use this API to e.g. generate an NSSKeylog * file and use it to inspect encrypted traffic in tools * such as Wireshark. * - Application-specific export: Use this API to implement * key exporters, e.g. for EAP-TLS or DTLS-SRTP. * * * \param ssl The SSL context to which the export * callback should be attached. * \param f_export_keys The callback for the key export. * \param p_export_keys The opaque context pointer to be passed to the * callback \p f_export_keys. */ void mbedtls_ssl_set_export_keys_cb( mbedtls_ssl_context *ssl, mbedtls_ssl_export_keys_t *f_export_keys, void *p_export_keys ); #endif /* MBEDTLS_SSL_EXPORT_KEYS */ #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) /** * \brief Configure asynchronous private key operation callbacks. * * \param conf SSL configuration context * \param f_async_sign Callback to start a signature operation. See * the description of ::mbedtls_ssl_async_sign_t * for more information. This may be \c NULL if the * external processor does not support any signature * operation; in this case the private key object * associated with the certificate will be used. * \param f_async_decrypt Callback to start a decryption operation. See * the description of ::mbedtls_ssl_async_decrypt_t * for more information. This may be \c NULL if the * external processor does not support any decryption * operation; in this case the private key object * associated with the certificate will be used. * \param f_async_resume Callback to resume an asynchronous operation. See * the description of ::mbedtls_ssl_async_resume_t * for more information. This may not be \c NULL unless * \p f_async_sign and \p f_async_decrypt are both * \c NULL. * \param f_async_cancel Callback to cancel an asynchronous operation. See * the description of ::mbedtls_ssl_async_cancel_t * for more information. This may be \c NULL if * no cleanup is needed. * \param config_data A pointer to configuration data which can be * retrieved with * mbedtls_ssl_conf_get_async_config_data(). The * library stores this value without dereferencing it. */ void mbedtls_ssl_conf_async_private_cb( mbedtls_ssl_config *conf, mbedtls_ssl_async_sign_t *f_async_sign, mbedtls_ssl_async_decrypt_t *f_async_decrypt, mbedtls_ssl_async_resume_t *f_async_resume, mbedtls_ssl_async_cancel_t *f_async_cancel, void *config_data ); /** * \brief Retrieve the configuration data set by * mbedtls_ssl_conf_async_private_cb(). * * \param conf SSL configuration context * \return The configuration data set by * mbedtls_ssl_conf_async_private_cb(). */ void *mbedtls_ssl_conf_get_async_config_data( const mbedtls_ssl_config *conf ); /** * \brief Retrieve the asynchronous operation user context. * * \note This function may only be called while a handshake * is in progress. * * \param ssl The SSL context to access. * * \return The asynchronous operation user context that was last * set during the current handshake. If * mbedtls_ssl_set_async_operation_data() has not yet been * called during the current handshake, this function returns * \c NULL. */ void *mbedtls_ssl_get_async_operation_data( const mbedtls_ssl_context *ssl ); /** * \brief Retrieve the asynchronous operation user context. * * \note This function may only be called while a handshake * is in progress. * * \param ssl The SSL context to access. * \param ctx The new value of the asynchronous operation user context. * Call mbedtls_ssl_get_async_operation_data() later during the * same handshake to retrieve this value. */ void mbedtls_ssl_set_async_operation_data( mbedtls_ssl_context *ssl, void *ctx ); #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ /** * \brief Callback type: generate a cookie * * \param ctx Context for the callback * \param p Buffer to write to, * must be updated to point right after the cookie * \param end Pointer to one past the end of the output buffer * \param info Client ID info that was passed to * \c mbedtls_ssl_set_client_transport_id() * \param ilen Length of info in bytes * * \return The callback must return 0 on success, * or a negative error code. */ typedef int mbedtls_ssl_cookie_write_t( void *ctx, unsigned char **p, unsigned char *end, const unsigned char *info, size_t ilen ); /** * \brief Callback type: verify a cookie * * \param ctx Context for the callback * \param cookie Cookie to verify * \param clen Length of cookie * \param info Client ID info that was passed to * \c mbedtls_ssl_set_client_transport_id() * \param ilen Length of info in bytes * * \return The callback must return 0 if cookie is valid, * or a negative error code. */ typedef int mbedtls_ssl_cookie_check_t( void *ctx, const unsigned char *cookie, size_t clen, const unsigned char *info, size_t ilen ); #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C) /** * \brief Register callbacks for DTLS cookies * (Server only. DTLS only.) * * Default: dummy callbacks that fail, in order to force you to * register working callbacks (and initialize their context). * * To disable HelloVerifyRequest, register NULL callbacks. * * \warning Disabling hello verification allows your server to be used * for amplification in DoS attacks against other hosts. * Only disable if you known this can't happen in your * particular environment. * * \note See comments on \c mbedtls_ssl_handshake() about handling * the MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED that is expected * on the first handshake attempt when this is enabled. * * \note This is also necessary to handle client reconnection from * the same port as described in RFC 6347 section 4.2.8 (only * the variant with cookies is supported currently). See * comments on \c mbedtls_ssl_read() for details. * * \param conf SSL configuration * \param f_cookie_write Cookie write callback * \param f_cookie_check Cookie check callback * \param p_cookie Context for both callbacks */ void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf, mbedtls_ssl_cookie_write_t *f_cookie_write, mbedtls_ssl_cookie_check_t *f_cookie_check, void *p_cookie ); /** * \brief Set client's transport-level identification info. * (Server only. DTLS only.) * * This is usually the IP address (and port), but could be * anything identify the client depending on the underlying * network stack. Used for HelloVerifyRequest with DTLS. * This is *not* used to route the actual packets. * * \param ssl SSL context * \param info Transport-level info identifying the client (eg IP + port) * \param ilen Length of info in bytes * * \note An internal copy is made, so the info buffer can be reused. * * \return 0 on success, * MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used on client, * MBEDTLS_ERR_SSL_ALLOC_FAILED if out of memory. */ int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl, const unsigned char *info, size_t ilen ); #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY && MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) /** * \brief Enable or disable anti-replay protection for DTLS. * (DTLS only, no effect on TLS.) * Default: enabled. * * \param conf SSL configuration * \param mode MBEDTLS_SSL_ANTI_REPLAY_ENABLED or MBEDTLS_SSL_ANTI_REPLAY_DISABLED. * * \warning Disabling this is a security risk unless the application * protocol handles duplicated packets in a safe way. You * should not disable this without careful consideration. * However, if your application already detects duplicated * packets and needs information about them to adjust its * transmission strategy, then you'll want to disable this. */ void mbedtls_ssl_conf_dtls_anti_replay( mbedtls_ssl_config *conf, char mode ); #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */ /** * \brief Set a limit on the number of records with a bad MAC * before terminating the connection. * (DTLS only, no effect on TLS.) * Default: 0 (disabled). * * \param conf SSL configuration * \param limit Limit, or 0 to disable. * * \note If the limit is N, then the connection is terminated when * the Nth non-authentic record is seen. * * \note Records with an invalid header are not counted, only the * ones going through the authentication-decryption phase. * * \note This is a security trade-off related to the fact that it's * often relatively easy for an active attacker ot inject UDP * datagrams. On one hand, setting a low limit here makes it * easier for such an attacker to forcibly terminated a * connection. On the other hand, a high limit or no limit * might make us waste resources checking authentication on * many bogus packets. */ void mbedtls_ssl_conf_dtls_badmac_limit( mbedtls_ssl_config *conf, unsigned limit ); #if defined(MBEDTLS_SSL_PROTO_DTLS) /** * \brief Allow or disallow packing of multiple handshake records * within a single datagram. * * \param ssl The SSL context to configure. * \param allow_packing This determines whether datagram packing may * be used or not. A value of \c 0 means that every * record will be sent in a separate datagram; a * value of \c 1 means that, if space permits, * multiple handshake messages (including CCS) belonging to * a single flight may be packed within a single datagram. * * \note This is enabled by default and should only be disabled * for test purposes, or if datagram packing causes * interoperability issues with peers that don't support it. * * \note Allowing datagram packing reduces the network load since * there's less overhead if multiple messages share the same * datagram. Also, it increases the handshake efficiency * since messages belonging to a single datagram will not * be reordered in transit, and so future message buffering * or flight retransmission (if no buffering is used) as * means to deal with reordering are needed less frequently. * * \note Application records are not affected by this option and * are currently always sent in separate datagrams. * */ void mbedtls_ssl_set_datagram_packing( mbedtls_ssl_context *ssl, unsigned allow_packing ); /** * \brief Set retransmit timeout values for the DTLS handshake. * (DTLS only, no effect on TLS.) * * \param conf SSL configuration * \param min Initial timeout value in milliseconds. * Default: 1000 (1 second). * \param max Maximum timeout value in milliseconds. * Default: 60000 (60 seconds). * * \note Default values are from RFC 6347 section 4.2.4.1. * * \note The 'min' value should typically be slightly above the * expected round-trip time to your peer, plus whatever time * it takes for the peer to process the message. For example, * if your RTT is about 600ms and you peer needs up to 1s to * do the cryptographic operations in the handshake, then you * should set 'min' slightly above 1600. Lower values of 'min' * might cause spurious resends which waste network resources, * while larger value of 'min' will increase overall latency * on unreliable network links. * * \note The more unreliable your network connection is, the larger * your max / min ratio needs to be in order to achieve * reliable handshakes. * * \note Messages are retransmitted up to log2(ceil(max/min)) times. * For example, if min = 1s and max = 5s, the retransmit plan * goes: send ... 1s -> resend ... 2s -> resend ... 4s -> * resend ... 5s -> give up and return a timeout error. */ void mbedtls_ssl_conf_handshake_timeout( mbedtls_ssl_config *conf, uint32_t min, uint32_t max ); #endif /* MBEDTLS_SSL_PROTO_DTLS */ #if defined(MBEDTLS_SSL_SRV_C) /** * \brief Set the session cache callbacks (server-side only) * If not set, no session resuming is done (except if session * tickets are enabled too). * * The session cache has the responsibility to check for stale * entries based on timeout. See RFC 5246 for recommendations. * * Warning: session.peer_cert is cleared by the SSL/TLS layer on * connection shutdown, so do not cache the pointer! Either set * it to NULL or make a full copy of the certificate. * * The get callback is called once during the initial handshake * to enable session resuming. The get function has the * following parameters: (void *parameter, mbedtls_ssl_session *session) * If a valid entry is found, it should fill the master of * the session object with the cached values and return 0, * return 1 otherwise. Optionally peer_cert can be set as well * if it is properly present in cache entry. * * The set callback is called once during the initial handshake * to enable session resuming after the entire handshake has * been finished. The set function has the following parameters: * (void *parameter, const mbedtls_ssl_session *session). The function * should create a cache entry for future retrieval based on * the data in the session structure and should keep in mind * that the mbedtls_ssl_session object presented (and all its referenced * data) is cleared by the SSL/TLS layer when the connection is * terminated. It is recommended to add metadata to determine if * an entry is still valid in the future. Return 0 if * successfully cached, return 1 otherwise. * * \param conf SSL configuration * \param p_cache parmater (context) for both callbacks * \param f_get_cache session get callback * \param f_set_cache session set callback */ void mbedtls_ssl_conf_session_cache( mbedtls_ssl_config *conf, void *p_cache, mbedtls_ssl_cache_get_t *f_get_cache, mbedtls_ssl_cache_set_t *f_set_cache ); #endif /* MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_CLI_C) /** * \brief Load a session for session resumption. * * Sessions loaded through this call will be considered * for session resumption in the next handshake. * * \note Even if this call succeeds, it is not guaranteed that * the next handshake will indeed be shortened through the * use of session resumption: The server is always free * to reject any attempt for resumption and fall back to * a full handshake. * * \note This function can handle a variety of mechanisms for session * resumption: For TLS 1.2, both session ID-based resumption and * ticket-based resumption will be considered. For TLS 1.3, * once implemented, sessions equate to tickets, and loading * one or more sessions via this call will lead to their * corresponding tickets being advertised as resumption PSKs * by the client. * * \note Calling this function multiple times will only be useful * once TLS 1.3 is supported. For TLS 1.2 connections, this * function should be called at most once. * * \param ssl The SSL context representing the connection which should * be attempted to be setup using session resumption. This * must be initialized via mbedtls_ssl_init() and bound to * an SSL configuration via mbedtls_ssl_setup(), but * the handshake must not yet have been started. * \param session The session to be considered for session resumption. * This must be a session previously exported via * mbedtls_ssl_get_session(), and potentially serialized and * deserialized through mbedtls_ssl_session_save() and * mbedtls_ssl_session_load() in the meantime. * * \return \c 0 if successful. * \return \c MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE if the session * could not be loaded because of an implementation limitation. * This error is non-fatal, and has no observable effect on * the SSL context or the session that was attempted to be loaded. * \return Another negative error code on other kinds of failure. * * \sa mbedtls_ssl_get_session() * \sa mbedtls_ssl_session_load() */ int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session *session ); #endif /* MBEDTLS_SSL_CLI_C */ /** * \brief Load serialized session data into a session structure. * On client, this can be used for loading saved sessions * before resuming them with mbedstls_ssl_set_session(). * On server, this can be used for alternative implementations * of session cache or session tickets. * * \warning If a peer certificate chain is associated with the session, * the serialized state will only contain the peer's * end-entity certificate and the result of the chain * verification (unless verification was disabled), but not * the rest of the chain. * * \see mbedtls_ssl_session_save() * \see mbedtls_ssl_set_session() * * \param session The session structure to be populated. It must have been * initialised with mbedtls_ssl_session_init() but not * populated yet. * \param buf The buffer holding the serialized session data. It must be a * readable buffer of at least \p len bytes. * \param len The size of the serialized data in bytes. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if input data is invalid. * \return #MBEDTLS_ERR_SSL_VERSION_MISMATCH if the serialized data * was generated in a different version or configuration of * Mbed TLS. * \return Another negative value for other kinds of errors (for * example, unsupported features in the embedded certificate). */ int mbedtls_ssl_session_load( mbedtls_ssl_session *session, const unsigned char *buf, size_t len ); /** * \brief Save session structure as serialized data in a buffer. * On client, this can be used for saving session data, * potentially in non-volatile storage, for resuming later. * On server, this can be used for alternative implementations * of session cache or session tickets. * * \see mbedtls_ssl_session_load() * * \param session The session structure to be saved. * \param buf The buffer to write the serialized data to. It must be a * writeable buffer of at least \p len bytes, or may be \c * NULL if \p len is \c 0. * \param buf_len The number of bytes available for writing in \p buf. * \param olen The size in bytes of the data that has been or would have * been written. It must point to a valid \c size_t. * * \note \p olen is updated to the correct value regardless of * whether \p buf_len was large enough. This makes it possible * to determine the necessary size by calling this function * with \p buf set to \c NULL and \p buf_len to \c 0. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if \p buf is too small. */ int mbedtls_ssl_session_save( const mbedtls_ssl_session *session, unsigned char *buf, size_t buf_len, size_t *olen ); /** * \brief Set the list of allowed ciphersuites and the preference * order. First in the list has the highest preference. * (Overrides all version-specific lists) * * The ciphersuites array is not copied, and must remain * valid for the lifetime of the ssl_config. * * Note: By default, the server chooses its preferred * ciphersuite among those that the client supports. If * mbedtls_ssl_conf_preference_order() is called to prefer * the client's preferences, the server instead chooses * the client's preferred ciphersuite among those that * the server supports. * * \param conf SSL configuration * \param ciphersuites 0-terminated list of allowed ciphersuites */ void mbedtls_ssl_conf_ciphersuites( mbedtls_ssl_config *conf, const int *ciphersuites ); #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) #define MBEDTLS_SSL_UNEXPECTED_CID_IGNORE 0 #define MBEDTLS_SSL_UNEXPECTED_CID_FAIL 1 /** * \brief Specify the length of Connection IDs for incoming * encrypted DTLS records, as well as the behaviour * on unexpected CIDs. * * By default, the CID length is set to \c 0, * and unexpected CIDs are silently ignored. * * \param conf The SSL configuration to modify. * \param len The length in Bytes of the CID fields in encrypted * DTLS records using the CID mechanism. This must * not be larger than #MBEDTLS_SSL_CID_OUT_LEN_MAX. * \param ignore_other_cids This determines the stack's behaviour when * receiving a record with an unexpected CID. * Possible values are: * - #MBEDTLS_SSL_UNEXPECTED_CID_IGNORE * In this case, the record is silently ignored. * - #MBEDTLS_SSL_UNEXPECTED_CID_FAIL * In this case, the stack fails with the specific * error code #MBEDTLS_ERR_SSL_UNEXPECTED_CID. * * \note The CID specification allows implementations to either * use a common length for all incoming connection IDs or * allow variable-length incoming IDs. Mbed TLS currently * requires a common length for all connections sharing the * same SSL configuration; this allows simpler parsing of * record headers. * * \return \c 0 on success. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if \p own_cid_len * is too large. */ int mbedtls_ssl_conf_cid( mbedtls_ssl_config *conf, size_t len, int ignore_other_cids ); #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Set the X.509 security profile used for verification * * \note The restrictions are enforced for all certificates in the * chain. However, signatures in the handshake are not covered * by this setting but by \b mbedtls_ssl_conf_sig_hashes(). * * \param conf SSL configuration * \param profile Profile to use */ void mbedtls_ssl_conf_cert_profile( mbedtls_ssl_config *conf, const mbedtls_x509_crt_profile *profile ); /** * \brief Set the data required to verify peer certificate * * \note See \c mbedtls_x509_crt_verify() for notes regarding the * parameters ca_chain (maps to trust_ca for that function) * and ca_crl. * * \param conf SSL configuration * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs) * \param ca_crl trusted CA CRLs */ void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf, mbedtls_x509_crt *ca_chain, mbedtls_x509_crl *ca_crl ); #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK) /** * \brief Set the trusted certificate callback. * * This API allows to register the set of trusted certificates * through a callback, instead of a linked list as configured * by mbedtls_ssl_conf_ca_chain(). * * This is useful for example in contexts where a large number * of CAs are used, and the inefficiency of maintaining them * in a linked list cannot be tolerated. It is also useful when * the set of trusted CAs needs to be modified frequently. * * See the documentation of `mbedtls_x509_crt_ca_cb_t` for * more information. * * \param conf The SSL configuration to register the callback with. * \param f_ca_cb The trusted certificate callback to use when verifying * certificate chains. * \param p_ca_cb The context to be passed to \p f_ca_cb (for example, * a reference to a trusted CA database). * * \note This API is incompatible with mbedtls_ssl_conf_ca_chain(): * Any call to this function overwrites the values set through * earlier calls to mbedtls_ssl_conf_ca_chain() or * mbedtls_ssl_conf_ca_cb(). * * \note This API is incompatible with CA indication in * CertificateRequest messages: A server-side SSL context which * is bound to an SSL configuration that uses a CA callback * configured via mbedtls_ssl_conf_ca_cb(), and which requires * client authentication, will send an empty CA list in the * corresponding CertificateRequest message. * * \note This API is incompatible with mbedtls_ssl_set_hs_ca_chain(): * If an SSL context is bound to an SSL configuration which uses * CA callbacks configured via mbedtls_ssl_conf_ca_cb(), then * calls to mbedtls_ssl_set_hs_ca_chain() have no effect. * * \note The use of this API disables the use of restartable ECC * during X.509 CRT signature verification (but doesn't affect * other uses). * * \warning This API is incompatible with the use of CRLs. Any call to * mbedtls_ssl_conf_ca_cb() unsets CRLs configured through * earlier calls to mbedtls_ssl_conf_ca_chain(). * * \warning In multi-threaded environments, the callback \p f_ca_cb * must be thread-safe, and it is the user's responsibility * to guarantee this (for example through a mutex * contained in the callback context pointed to by \p p_ca_cb). */ void mbedtls_ssl_conf_ca_cb( mbedtls_ssl_config *conf, mbedtls_x509_crt_ca_cb_t f_ca_cb, void *p_ca_cb ); #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */ /** * \brief Set own certificate chain and private key * * \note own_cert should contain in order from the bottom up your * certificate chain. The top certificate (self-signed) * can be omitted. * * \note On server, this function can be called multiple times to * provision more than one cert/key pair (eg one ECDSA, one * RSA with SHA-256, one RSA with SHA-1). An adequate * certificate will be selected according to the client's * advertised capabilities. In case multiple certificates are * adequate, preference is given to the one set by the first * call to this function, then second, etc. * * \note On client, only the first call has any effect. That is, * only one client certificate can be provisioned. The * server's preferences in its CertficateRequest message will * be ignored and our only cert will be sent regardless of * whether it matches those preferences - the server can then * decide what it wants to do with it. * * \note The provided \p pk_key needs to match the public key in the * first certificate in \p own_cert, or all handshakes using * that certificate will fail. It is your responsibility * to ensure that; this function will not perform any check. * You may use mbedtls_pk_check_pair() in order to perform * this check yourself, but be aware that this function can * be computationally expensive on some key types. * * \param conf SSL configuration * \param own_cert own public certificate chain * \param pk_key own private key * * \return 0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED */ int mbedtls_ssl_conf_own_cert( mbedtls_ssl_config *conf, mbedtls_x509_crt *own_cert, mbedtls_pk_context *pk_key ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) /** * \brief Configure pre-shared keys (PSKs) and their * identities to be used in PSK-based ciphersuites. * * Only one PSK can be registered, through either * mbedtls_ssl_conf_psk() or mbedtls_ssl_conf_psk_opaque(). * If you attempt to register more than one PSK, this function * fails, though this may change in future versions, which * may add support for multiple PSKs. * * \note This is mainly useful for clients. Servers will usually * want to use \c mbedtls_ssl_conf_psk_cb() instead. * * \note A PSK set by \c mbedtls_ssl_set_hs_psk() in the PSK callback * takes precedence over a PSK configured by this function. * * \param conf The SSL configuration to register the PSK with. * \param psk The pointer to the pre-shared key to use. * \param psk_len The length of the pre-shared key in bytes. * \param psk_identity The pointer to the pre-shared key identity. * \param psk_identity_len The length of the pre-shared key identity * in bytes. * * \note The PSK and its identity are copied internally and * hence need not be preserved by the caller for the lifetime * of the SSL configuration. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE if no more PSKs * can be configured. In this case, the old PSK(s) remain intact. * \return Another negative error code on other kinds of failure. */ int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf, const unsigned char *psk, size_t psk_len, const unsigned char *psk_identity, size_t psk_identity_len ); #if defined(MBEDTLS_USE_PSA_CRYPTO) /** * \brief Configure one or more opaque pre-shared keys (PSKs) and * their identities to be used in PSK-based ciphersuites. * * Only one PSK can be registered, through either * mbedtls_ssl_conf_psk() or mbedtls_ssl_conf_psk_opaque(). * If you attempt to register more than one PSK, this function * fails, though this may change in future versions, which * may add support for multiple PSKs. * * \note This is mainly useful for clients. Servers will usually * want to use \c mbedtls_ssl_conf_psk_cb() instead. * * \note An opaque PSK set by \c mbedtls_ssl_set_hs_psk_opaque() in * the PSK callback takes precedence over an opaque PSK * configured by this function. * * \param conf The SSL configuration to register the PSK with. * \param psk The identifier of the key slot holding the PSK. * Until \p conf is destroyed or this function is successfully * called again, the key slot \p psk must be populated with a * key of type PSA_ALG_CATEGORY_KEY_DERIVATION whose policy * allows its use for the key derivation algorithm applied * in the handshake. * \param psk_identity The pointer to the pre-shared key identity. * \param psk_identity_len The length of the pre-shared key identity * in bytes. * * \note The PSK identity hint is copied internally and hence need * not be preserved by the caller for the lifetime of the * SSL configuration. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE if no more PSKs * can be configured. In this case, the old PSK(s) remain intact. * \return Another negative error code on other kinds of failure. */ int mbedtls_ssl_conf_psk_opaque( mbedtls_ssl_config *conf, psa_key_id_t psk, const unsigned char *psk_identity, size_t psk_identity_len ); #endif /* MBEDTLS_USE_PSA_CRYPTO */ /** * \brief Set the pre-shared Key (PSK) for the current handshake. * * \note This should only be called inside the PSK callback, * i.e. the function passed to \c mbedtls_ssl_conf_psk_cb(). * * \note A PSK set by this function takes precedence over a PSK * configured by \c mbedtls_ssl_conf_psk(). * * \param ssl The SSL context to configure a PSK for. * \param psk The pointer to the pre-shared key. * \param psk_len The length of the pre-shared key in bytes. * * \return \c 0 if successful. * \return An \c MBEDTLS_ERR_SSL_XXX error code on failure. */ int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl, const unsigned char *psk, size_t psk_len ); #if defined(MBEDTLS_USE_PSA_CRYPTO) /** * \brief Set an opaque pre-shared Key (PSK) for the current handshake. * * \note This should only be called inside the PSK callback, * i.e. the function passed to \c mbedtls_ssl_conf_psk_cb(). * * \note An opaque PSK set by this function takes precedence over an * opaque PSK configured by \c mbedtls_ssl_conf_psk_opaque(). * * \param ssl The SSL context to configure a PSK for. * \param psk The identifier of the key slot holding the PSK. * For the duration of the current handshake, the key slot * must be populated with a key of type * PSA_ALG_CATEGORY_KEY_DERIVATION whose policy allows its * use for the key derivation algorithm * applied in the handshake. * * \return \c 0 if successful. * \return An \c MBEDTLS_ERR_SSL_XXX error code on failure. */ int mbedtls_ssl_set_hs_psk_opaque( mbedtls_ssl_context *ssl, psa_key_id_t psk ); #endif /* MBEDTLS_USE_PSA_CRYPTO */ /** * \brief Set the PSK callback (server-side only). * * If set, the PSK callback is called for each * handshake where a PSK-based ciphersuite was negotiated. * The caller provides the identity received and wants to * receive the actual PSK data and length. * * The callback has the following parameters: * - \c void*: The opaque pointer \p p_psk. * - \c mbedtls_ssl_context*: The SSL context to which * the operation applies. * - \c const unsigned char*: The PSK identity * selected by the client. * - \c size_t: The length of the PSK identity * selected by the client. * * If a valid PSK identity is found, the callback should use * \c mbedtls_ssl_set_hs_psk() or * \c mbedtls_ssl_set_hs_psk_opaque() * on the SSL context to set the correct PSK and return \c 0. * Any other return value will result in a denied PSK identity. * * \note A dynamic PSK (i.e. set by the PSK callback) takes * precedence over a static PSK (i.e. set by * \c mbedtls_ssl_conf_psk() or * \c mbedtls_ssl_conf_psk_opaque()). * This means that if you set a PSK callback using this * function, you don't need to set a PSK using * \c mbedtls_ssl_conf_psk() or * \c mbedtls_ssl_conf_psk_opaque()). * * \param conf The SSL configuration to register the callback with. * \param f_psk The callback for selecting and setting the PSK based * in the PSK identity chosen by the client. * \param p_psk A pointer to an opaque structure to be passed to * the callback, for example a PSK store. */ void mbedtls_ssl_conf_psk_cb( mbedtls_ssl_config *conf, int (*f_psk)(void *, mbedtls_ssl_context *, const unsigned char *, size_t), void *p_psk ); #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C) /** * \brief Set the Diffie-Hellman public P and G values * from big-endian binary presentations. * (Default values: MBEDTLS_DHM_RFC3526_MODP_2048_[PG]_BIN) * * \param conf SSL configuration * \param dhm_P Diffie-Hellman-Merkle modulus in big-endian binary form * \param P_len Length of DHM modulus * \param dhm_G Diffie-Hellman-Merkle generator in big-endian binary form * \param G_len Length of DHM generator * * \return 0 if successful */ int mbedtls_ssl_conf_dh_param_bin( mbedtls_ssl_config *conf, const unsigned char *dhm_P, size_t P_len, const unsigned char *dhm_G, size_t G_len ); /** * \brief Set the Diffie-Hellman public P and G values, * read from existing context (server-side only) * * \param conf SSL configuration * \param dhm_ctx Diffie-Hellman-Merkle context * * \return 0 if successful */ int mbedtls_ssl_conf_dh_param_ctx( mbedtls_ssl_config *conf, mbedtls_dhm_context *dhm_ctx ); #endif /* MBEDTLS_DHM_C && defined(MBEDTLS_SSL_SRV_C) */ #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C) /** * \brief Set the minimum length for Diffie-Hellman parameters. * (Client-side only.) * (Default: 1024 bits.) * * \param conf SSL configuration * \param bitlen Minimum bit length of the DHM prime */ void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf, unsigned int bitlen ); #endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_ECP_C) /** * \brief Set the allowed curves in order of preference. * * On server: this only affects selection of the ECDHE curve; * the curves used for ECDH and ECDSA are determined by the * list of available certificates instead. * * On client: this affects the list of curves offered for any * use. The server can override our preference order. * * Both sides: limits the set of curves accepted for use in * ECDHE and in the peer's end-entity certificate. * * \note This has no influence on which curves are allowed inside the * certificate chains, see \c mbedtls_ssl_conf_cert_profile() * for that. For the end-entity certificate however, the key * will be accepted only if it is allowed both by this list * and by the cert profile. * * \note This list should be ordered by decreasing preference * (preferred curve first). * * \note The default list is the same set of curves that * #mbedtls_x509_crt_profile_default allows, plus * ECDHE-only curves selected according to the same criteria. * The order favors curves with the lowest resource usage. * * \note New minor versions of Mbed TLS may extend this list, * for example if new curves are added to the library. * New minor versions of Mbed TLS will not remove items * from this list unless serious security concerns require it. * New minor versions of Mbed TLS may change the order in * keeping with the general principle of favoring the lowest * resource usage. * * \param conf SSL configuration * \param curves Ordered list of allowed curves, * terminated by MBEDTLS_ECP_DP_NONE. */ void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf, const mbedtls_ecp_group_id *curves ); #endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) /** * \brief Set the allowed hashes for signatures during the handshake. * * \note This only affects which hashes are offered and can be used * for signatures during the handshake. Hashes for message * authentication and the TLS PRF are controlled by the * ciphersuite, see \c mbedtls_ssl_conf_ciphersuites(). Hashes * used for certificate signature are controlled by the * verification profile, see \c mbedtls_ssl_conf_cert_profile(). * * \note This list should be ordered by decreasing preference * (preferred hash first). * * \note By default, all supported hashes whose length is at least * 256 bits are allowed. This is the same set as the default * for certificate verification * (#mbedtls_x509_crt_profile_default). * The preference order is currently unspecified and may * change in future versions. * * \note New minor versions of Mbed TLS may extend this list, * for example if new curves are added to the library. * New minor versions of Mbed TLS will not remove items * from this list unless serious security concerns require it. * * \param conf SSL configuration * \param hashes Ordered list of allowed signature hashes, * terminated by \c MBEDTLS_MD_NONE. */ void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf, const int *hashes ); #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Set or reset the hostname to check against the received * server certificate. It sets the ServerName TLS extension, * too, if that extension is enabled. (client-side only) * * \param ssl SSL context * \param hostname the server hostname, may be NULL to clear hostname * \note Maximum hostname length MBEDTLS_SSL_MAX_HOST_NAME_LEN. * * \return 0 if successful, MBEDTLS_ERR_SSL_ALLOC_FAILED on * allocation failure, MBEDTLS_ERR_SSL_BAD_INPUT_DATA on * too long input hostname. * * Hostname set to the one provided on success (cleared * when NULL). On allocation failure hostname is cleared. * On too long input failure, old hostname is unchanged. */ int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) /** * \brief Set own certificate and key for the current handshake * * \note Same as \c mbedtls_ssl_conf_own_cert() but for use within * the SNI callback. * * \param ssl SSL context * \param own_cert own public certificate chain * \param pk_key own private key * * \return 0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED */ int mbedtls_ssl_set_hs_own_cert( mbedtls_ssl_context *ssl, mbedtls_x509_crt *own_cert, mbedtls_pk_context *pk_key ); /** * \brief Set the data required to verify peer certificate for the * current handshake * * \note Same as \c mbedtls_ssl_conf_ca_chain() but for use within * the SNI callback. * * \param ssl SSL context * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs) * \param ca_crl trusted CA CRLs */ void mbedtls_ssl_set_hs_ca_chain( mbedtls_ssl_context *ssl, mbedtls_x509_crt *ca_chain, mbedtls_x509_crl *ca_crl ); /** * \brief Set authmode for the current handshake. * * \note Same as \c mbedtls_ssl_conf_authmode() but for use within * the SNI callback. * * \param ssl SSL context * \param authmode MBEDTLS_SSL_VERIFY_NONE, MBEDTLS_SSL_VERIFY_OPTIONAL or * MBEDTLS_SSL_VERIFY_REQUIRED */ void mbedtls_ssl_set_hs_authmode( mbedtls_ssl_context *ssl, int authmode ); /** * \brief Set server side ServerName TLS extension callback * (optional, server-side only). * * If set, the ServerName callback is called whenever the * server receives a ServerName TLS extension from the client * during a handshake. The ServerName callback has the * following parameters: (void *parameter, mbedtls_ssl_context *ssl, * const unsigned char *hostname, size_t len). If a suitable * certificate is found, the callback must set the * certificate(s) and key(s) to use with \c * mbedtls_ssl_set_hs_own_cert() (can be called repeatedly), * and may optionally adjust the CA and associated CRL with \c * mbedtls_ssl_set_hs_ca_chain() as well as the client * authentication mode with \c mbedtls_ssl_set_hs_authmode(), * then must return 0. If no matching name is found, the * callback must either set a default cert, or * return non-zero to abort the handshake at this point. * * \param conf SSL configuration * \param f_sni verification function * \param p_sni verification parameter */ void mbedtls_ssl_conf_sni( mbedtls_ssl_config *conf, int (*f_sni)(void *, mbedtls_ssl_context *, const unsigned char *, size_t), void *p_sni ); #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) /** * \brief Set the EC J-PAKE password for current handshake. * * \note An internal copy is made, and destroyed as soon as the * handshake is completed, or when the SSL context is reset or * freed. * * \note The SSL context needs to be already set up. The right place * to call this function is between \c mbedtls_ssl_setup() or * \c mbedtls_ssl_reset() and \c mbedtls_ssl_handshake(). * * \param ssl SSL context * \param pw EC J-PAKE password (pre-shared secret) * \param pw_len length of pw in bytes * * \return 0 on success, or a negative error code. */ int mbedtls_ssl_set_hs_ecjpake_password( mbedtls_ssl_context *ssl, const unsigned char *pw, size_t pw_len ); #endif /*MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_SSL_ALPN) /** * \brief Set the supported Application Layer Protocols. * * \param conf SSL configuration * \param protos Pointer to a NULL-terminated list of supported protocols, * in decreasing preference order. The pointer to the list is * recorded by the library for later reference as required, so * the lifetime of the table must be atleast as long as the * lifetime of the SSL configuration structure. * * \return 0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA. */ int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **protos ); /** * \brief Get the name of the negotiated Application Layer Protocol. * This function should be called after the handshake is * completed. * * \param ssl SSL context * * \return Protcol name, or NULL if no protocol was negotiated. */ const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ); #endif /* MBEDTLS_SSL_ALPN */ #if defined(MBEDTLS_SSL_DTLS_SRTP) #if defined(MBEDTLS_DEBUG_C) static inline const char *mbedtls_ssl_get_srtp_profile_as_string( mbedtls_ssl_srtp_profile profile ) { switch( profile ) { case MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_80: return( "MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_80" ); case MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_32: return( "MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_32" ); case MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_80: return( "MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_80" ); case MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_32: return( "MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_32" ); default: break; } return( "" ); } #endif /* MBEDTLS_DEBUG_C */ /** * \brief Manage support for mki(master key id) value * in use_srtp extension. * MKI is an optional part of SRTP used for key management * and re-keying. See RFC3711 section 3.1 for details. * The default value is * #MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED. * * \param conf The SSL configuration to manage mki support. * \param support_mki_value Enable or disable mki usage. Values are * #MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED * or #MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED. */ void mbedtls_ssl_conf_srtp_mki_value_supported( mbedtls_ssl_config *conf, int support_mki_value ); /** * \brief Set the supported DTLS-SRTP protection profiles. * * \param conf SSL configuration * \param profiles Pointer to a List of MBEDTLS_TLS_SRTP_UNSET terminated * supported protection profiles * in decreasing preference order. * The pointer to the list is recorded by the library * for later reference as required, so the lifetime * of the table must be at least as long as the lifetime * of the SSL configuration structure. * The list must not hold more than * MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH elements * (excluding the terminating MBEDTLS_TLS_SRTP_UNSET). * * \return 0 on success * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA when the list of * protection profiles is incorrect. */ int mbedtls_ssl_conf_dtls_srtp_protection_profiles ( mbedtls_ssl_config *conf, const mbedtls_ssl_srtp_profile *profiles ); /** * \brief Set the mki_value for the current DTLS-SRTP session. * * \param ssl SSL context to use. * \param mki_value The MKI value to set. * \param mki_len The length of the MKI value. * * \note This function is relevant on client side only. * The server discovers the mki value during handshake. * A mki value set on server side using this function * is ignored. * * \return 0 on success * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA * \return #MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE */ int mbedtls_ssl_dtls_srtp_set_mki_value( mbedtls_ssl_context *ssl, unsigned char *mki_value, uint16_t mki_len ); /** * \brief Get the negotiated DTLS-SRTP informations: * Protection profile and MKI value. * * \warning This function must be called after the handshake is * completed. The value returned by this function must * not be trusted or acted upon before the handshake completes. * * \param ssl The SSL context to query. * \param dtls_srtp_info The negotiated DTLS-SRTP informations: * - Protection profile in use. * A direct mapping of the iana defined value for protection * profile on an uint16_t. http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml * #MBEDTLS_TLS_SRTP_UNSET if the use of SRTP was not negotiated * or peer's Hello packet was not parsed yet. * - mki size and value( if size is > 0 ). */ void mbedtls_ssl_get_dtls_srtp_negotiation_result( const mbedtls_ssl_context *ssl, mbedtls_dtls_srtp_info *dtls_srtp_info ); #endif /* MBEDTLS_SSL_DTLS_SRTP */ /** * \brief Set the maximum supported version sent from the client side * and/or accepted at the server side * (Default: MBEDTLS_SSL_MAX_MAJOR_VERSION, MBEDTLS_SSL_MAX_MINOR_VERSION) * * \note This ignores ciphersuites from higher versions. * * \note With DTLS, use MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2 * * \param conf SSL configuration * \param major Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported) * \param minor Minor version number (only MBEDTLS_SSL_MINOR_VERSION_3 supported) */ void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor ); /** * \brief Set the minimum accepted SSL/TLS protocol version * (Default: TLS 1.2) * * \note Input outside of the SSL_MAX_XXXXX_VERSION and * SSL_MIN_XXXXX_VERSION range is ignored. * * \note With DTLS, use MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2 * * \param conf SSL configuration * \param major Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported) * \param minor Minor version number (only MBEDTLS_SSL_MINOR_VERSION_3 supported) */ void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor ); #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) /** * \brief Enable or disable Encrypt-then-MAC * (Default: MBEDTLS_SSL_ETM_ENABLED) * * \note This should always be enabled, it is a security * improvement, and should not cause any interoperability * issue (used only if the peer supports it too). * * \param conf SSL configuration * \param etm MBEDTLS_SSL_ETM_ENABLED or MBEDTLS_SSL_ETM_DISABLED */ void mbedtls_ssl_conf_encrypt_then_mac( mbedtls_ssl_config *conf, char etm ); #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) /** * \brief Enable or disable Extended Master Secret negotiation. * (Default: MBEDTLS_SSL_EXTENDED_MS_ENABLED) * * \note This should always be enabled, it is a security fix to the * protocol, and should not cause any interoperability issue * (used only if the peer supports it too). * * \param conf SSL configuration * \param ems MBEDTLS_SSL_EXTENDED_MS_ENABLED or MBEDTLS_SSL_EXTENDED_MS_DISABLED */ void mbedtls_ssl_conf_extended_master_secret( mbedtls_ssl_config *conf, char ems ); #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ #if defined(MBEDTLS_SSL_SRV_C) /** * \brief Whether to send a list of acceptable CAs in * CertificateRequest messages. * (Default: do send) * * \param conf SSL configuration * \param cert_req_ca_list MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED or * MBEDTLS_SSL_CERT_REQ_CA_LIST_DISABLED */ void mbedtls_ssl_conf_cert_req_ca_list( mbedtls_ssl_config *conf, char cert_req_ca_list ); #endif /* MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) /** * \brief Set the maximum fragment length to emit and/or negotiate. * (Typical: the smaller of #MBEDTLS_SSL_IN_CONTENT_LEN and * #MBEDTLS_SSL_OUT_CONTENT_LEN, usually `2^14` bytes) * (Server: set maximum fragment length to emit, * usually negotiated by the client during handshake) * (Client: set maximum fragment length to emit *and* * negotiate with the server during handshake) * (Default: #MBEDTLS_SSL_MAX_FRAG_LEN_NONE) * * \note On the client side, the maximum fragment length extension * *will not* be used, unless the maximum fragment length has * been set via this function to a value different than * #MBEDTLS_SSL_MAX_FRAG_LEN_NONE. * * \note With TLS, this currently only affects ApplicationData (sent * with \c mbedtls_ssl_read()), not handshake messages. * With DTLS, this affects both ApplicationData and handshake. * * \note This sets the maximum length for a record's payload, * excluding record overhead that will be added to it, see * \c mbedtls_ssl_get_record_expansion(). * * \note For DTLS, it is also possible to set a limit for the total * size of daragrams passed to the transport layer, including * record overhead, see \c mbedtls_ssl_set_mtu(). * * \param conf SSL configuration * \param mfl_code Code for maximum fragment length (allowed values: * MBEDTLS_SSL_MAX_FRAG_LEN_512, MBEDTLS_SSL_MAX_FRAG_LEN_1024, * MBEDTLS_SSL_MAX_FRAG_LEN_2048, MBEDTLS_SSL_MAX_FRAG_LEN_4096) * * \return 0 if successful or MBEDTLS_ERR_SSL_BAD_INPUT_DATA */ int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_code ); #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_SRV_C) /** * \brief Pick the ciphersuites order according to the second parameter * in the SSL Server module (MBEDTLS_SSL_SRV_C). * (Default, if never called: MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_SERVER) * * \param conf SSL configuration * \param order Server or client (MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_SERVER * or MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_CLIENT) */ void mbedtls_ssl_conf_preference_order( mbedtls_ssl_config *conf, int order ); #endif /* MBEDTLS_SSL_SRV_C */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C) /** * \brief Enable / Disable session tickets (client only). * (Default: MBEDTLS_SSL_SESSION_TICKETS_ENABLED.) * * \note On server, use \c mbedtls_ssl_conf_session_tickets_cb(). * * \param conf SSL configuration * \param use_tickets Enable or disable (MBEDTLS_SSL_SESSION_TICKETS_ENABLED or * MBEDTLS_SSL_SESSION_TICKETS_DISABLED) */ void mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets ); #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */ #if defined(MBEDTLS_SSL_RENEGOTIATION) /** * \brief Enable / Disable renegotiation support for connection when * initiated by peer * (Default: MBEDTLS_SSL_RENEGOTIATION_DISABLED) * * \warning It is recommended to always disable renegotation unless you * know you need it and you know what you're doing. In the * past, there have been several issues associated with * renegotiation or a poor understanding of its properties. * * \note Server-side, enabling renegotiation also makes the server * susceptible to a resource DoS by a malicious client. * * \param conf SSL configuration * \param renegotiation Enable or disable (MBEDTLS_SSL_RENEGOTIATION_ENABLED or * MBEDTLS_SSL_RENEGOTIATION_DISABLED) */ void mbedtls_ssl_conf_renegotiation( mbedtls_ssl_config *conf, int renegotiation ); #endif /* MBEDTLS_SSL_RENEGOTIATION */ /** * \brief Prevent or allow legacy renegotiation. * (Default: MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION) * * MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION allows connections to * be established even if the peer does not support * secure renegotiation, but does not allow renegotiation * to take place if not secure. * (Interoperable and secure option) * * MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION allows renegotiations * with non-upgraded peers. Allowing legacy renegotiation * makes the connection vulnerable to specific man in the * middle attacks. (See RFC 5746) * (Most interoperable and least secure option) * * MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE breaks off connections * if peer does not support secure renegotiation. Results * in interoperability issues with non-upgraded peers * that do not support renegotiation altogether. * (Most secure option, interoperability issues) * * \param conf SSL configuration * \param allow_legacy Prevent or allow (SSL_NO_LEGACY_RENEGOTIATION, * SSL_ALLOW_LEGACY_RENEGOTIATION or * MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE) */ void mbedtls_ssl_conf_legacy_renegotiation( mbedtls_ssl_config *conf, int allow_legacy ); #if defined(MBEDTLS_SSL_RENEGOTIATION) /** * \brief Enforce renegotiation requests. * (Default: enforced, max_records = 16) * * When we request a renegotiation, the peer can comply or * ignore the request. This function allows us to decide * whether to enforce our renegotiation requests by closing * the connection if the peer doesn't comply. * * However, records could already be in transit from the peer * when the request is emitted. In order to increase * reliability, we can accept a number of records before the * expected handshake records. * * The optimal value is highly dependent on the specific usage * scenario. * * \note With DTLS and server-initiated renegotiation, the * HelloRequest is retransmited every time mbedtls_ssl_read() times * out or receives Application Data, until: * - max_records records have beens seen, if it is >= 0, or * - the number of retransmits that would happen during an * actual handshake has been reached. * Please remember the request might be lost a few times * if you consider setting max_records to a really low value. * * \warning On client, the grace period can only happen during * mbedtls_ssl_read(), as opposed to mbedtls_ssl_write() and mbedtls_ssl_renegotiate() * which always behave as if max_record was 0. The reason is, * if we receive application data from the server, we need a * place to write it, which only happens during mbedtls_ssl_read(). * * \param conf SSL configuration * \param max_records Use MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED if you don't want to * enforce renegotiation, or a non-negative value to enforce * it but allow for a grace period of max_records records. */ void mbedtls_ssl_conf_renegotiation_enforced( mbedtls_ssl_config *conf, int max_records ); /** * \brief Set record counter threshold for periodic renegotiation. * (Default: 2^48 - 1) * * Renegotiation is automatically triggered when a record * counter (outgoing or incoming) crosses the defined * threshold. The default value is meant to prevent the * connection from being closed when the counter is about to * reached its maximal value (it is not allowed to wrap). * * Lower values can be used to enforce policies such as "keys * must be refreshed every N packets with cipher X". * * The renegotiation period can be disabled by setting * conf->disable_renegotiation to * MBEDTLS_SSL_RENEGOTIATION_DISABLED. * * \note When the configured transport is * MBEDTLS_SSL_TRANSPORT_DATAGRAM the maximum renegotiation * period is 2^48 - 1, and for MBEDTLS_SSL_TRANSPORT_STREAM, * the maximum renegotiation period is 2^64 - 1. * * \param conf SSL configuration * \param period The threshold value: a big-endian 64-bit number. */ void mbedtls_ssl_conf_renegotiation_period( mbedtls_ssl_config *conf, const unsigned char period[8] ); #endif /* MBEDTLS_SSL_RENEGOTIATION */ /** * \brief Check if there is data already read from the * underlying transport but not yet processed. * * \param ssl SSL context * * \return 0 if nothing's pending, 1 otherwise. * * \note This is different in purpose and behaviour from * \c mbedtls_ssl_get_bytes_avail in that it considers * any kind of unprocessed data, not only unread * application data. If \c mbedtls_ssl_get_bytes * returns a non-zero value, this function will * also signal pending data, but the converse does * not hold. For example, in DTLS there might be * further records waiting to be processed from * the current underlying transport's datagram. * * \note If this function returns 1 (data pending), this * does not imply that a subsequent call to * \c mbedtls_ssl_read will provide any data; * e.g., the unprocessed data might turn out * to be an alert or a handshake message. * * \note This function is useful in the following situation: * If the SSL/TLS module successfully returns from an * operation - e.g. a handshake or an application record * read - and you're awaiting incoming data next, you * must not immediately idle on the underlying transport * to have data ready, but you need to check the value * of this function first. The reason is that the desired * data might already be read but not yet processed. * If, in contrast, a previous call to the SSL/TLS module * returned MBEDTLS_ERR_SSL_WANT_READ, it is not necessary * to call this function, as the latter error code entails * that all internal data has been processed. * */ int mbedtls_ssl_check_pending( const mbedtls_ssl_context *ssl ); /** * \brief Return the number of application data bytes * remaining to be read from the current record. * * \param ssl SSL context * * \return How many bytes are available in the application * data record read buffer. * * \note When working over a datagram transport, this is * useful to detect the current datagram's boundary * in case \c mbedtls_ssl_read has written the maximal * amount of data fitting into the input buffer. * */ size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl ); /** * \brief Return the result of the certificate verification * * \param ssl The SSL context to use. * * \return \c 0 if the certificate verification was successful. * \return \c -1u if the result is not available. This may happen * e.g. if the handshake aborts early, or a verification * callback returned a fatal error. * \return A bitwise combination of \c MBEDTLS_X509_BADCERT_XXX * and \c MBEDTLS_X509_BADCRL_XXX failure flags; see x509.h. */ uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl ); /** * \brief Return the name of the current ciphersuite * * \param ssl SSL context * * \return a string containing the ciphersuite name */ const char *mbedtls_ssl_get_ciphersuite( const mbedtls_ssl_context *ssl ); /** * \brief Return the current TLS version * * \param ssl SSL context * * \return a string containing the TLS version */ const char *mbedtls_ssl_get_version( const mbedtls_ssl_context *ssl ); /** * \brief Return the (maximum) number of bytes added by the record * layer: header + encryption/MAC overhead (inc. padding) * * \param ssl SSL context * * \return Current maximum record expansion in bytes */ int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl ); /** * \brief Return the current maximum outgoing record payload in bytes. * * \note The logic to determine the maximum outgoing record payload is * version-specific. It takes into account various factors, such as * the mbedtls_config.h setting \c MBEDTLS_SSL_OUT_CONTENT_LEN, extensions * such as the max fragment length or record size limit extension if * used, and for DTLS the path MTU as configured and current * record expansion. * * \note With DTLS, \c mbedtls_ssl_write() will return an error if * called with a larger length value. * With TLS, \c mbedtls_ssl_write() will fragment the input if * necessary and return the number of bytes written; it is up * to the caller to call \c mbedtls_ssl_write() again in * order to send the remaining bytes if any. * * \sa mbedtls_ssl_get_max_out_record_payload() * \sa mbedtls_ssl_get_record_expansion() * * \param ssl SSL context * * \return Current maximum payload for an outgoing record, * or a negative error code. */ int mbedtls_ssl_get_max_out_record_payload( const mbedtls_ssl_context *ssl ); /** * \brief Return the current maximum incoming record payload in bytes. * * \note The logic to determine the maximum outgoing record payload is * version-specific. It takes into account various factors, such as * the mbedtls_config.h setting \c MBEDTLS_SSL_IN_CONTENT_LEN, extensions * such as the max fragment length extension or record size limit * extension if used, and the current record expansion. * * \sa mbedtls_ssl_set_mtu() * \sa mbedtls_ssl_get_max_in_record_payload() * \sa mbedtls_ssl_get_record_expansion() * * \param ssl SSL context * * \return Current maximum payload for an outgoing record, * or a negative error code. */ int mbedtls_ssl_get_max_in_record_payload( const mbedtls_ssl_context *ssl ); #if defined(MBEDTLS_X509_CRT_PARSE_C) /** * \brief Return the peer certificate from the current connection. * * \param ssl The SSL context to use. This must be initialized and setup. * * \return The current peer certificate, if available. * The returned certificate is owned by the SSL context and * is valid only until the next call to the SSL API. * \return \c NULL if no peer certificate is available. This might * be because the chosen ciphersuite doesn't use CRTs * (PSK-based ciphersuites, for example), or because * #MBEDTLS_SSL_KEEP_PEER_CERTIFICATE has been disabled, * allowing the stack to free the peer's CRT to save memory. * * \note For one-time inspection of the peer's certificate during * the handshake, consider registering an X.509 CRT verification * callback through mbedtls_ssl_conf_verify() instead of calling * this function. Using mbedtls_ssl_conf_verify() also comes at * the benefit of allowing you to influence the verification * process, for example by masking expected and tolerated * verification failures. * * \warning You must not use the pointer returned by this function * after any further call to the SSL API, including * mbedtls_ssl_read() and mbedtls_ssl_write(); this is * because the pointer might change during renegotiation, * which happens transparently to the user. * If you want to use the certificate across API calls, * you must make a copy. */ const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl ); #endif /* MBEDTLS_X509_CRT_PARSE_C */ #if defined(MBEDTLS_SSL_CLI_C) /** * \brief Export a session in order to resume it later. * * \param ssl The SSL context representing the connection for which to * to export a session structure for later resumption. * \param session The target structure in which to store the exported session. * This must have been initialized with mbedtls_ssl_init_session() * but otherwise be unused. * * \note This function can handle a variety of mechanisms for session * resumption: For TLS 1.2, both session ID-based resumption and * ticket-based resumption will be considered. For TLS 1.3, * once implemented, sessions equate to tickets, and calling * this function multiple times will export the available * tickets one a time until no further tickets are available, * in which case MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE will * be returned. * * \note Calling this function multiple times will only be useful * once TLS 1.3 is supported. For TLS 1.2 connections, this * function should be called at most once. * * \return \c 0 if successful. In this case, \p session can be used for * session resumption by passing it to mbedtls_ssl_set_session(), * and serialized for storage via mbedtls_ssl_session_save(). * \return #MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE if no further session * is available for export. * This error is a non-fatal, and has no observable effect on * the SSL context or the destination session. * \return Another negative error code on other kinds of failure. * * \sa mbedtls_ssl_set_session() * \sa mbedtls_ssl_session_save() */ int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session *session ); #endif /* MBEDTLS_SSL_CLI_C */ /** * \brief Perform the SSL handshake * * \param ssl SSL context * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE * if the handshake is incomplete and waiting for data to * be available for reading from or writing to the underlying * transport - in this case you must call this function again * when the underlying transport is ready for the operation. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous * operation is in progress (see * mbedtls_ssl_conf_async_private_cb()) - in this case you * must call this function again when the operation is ready. * \return #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic * operation is in progress (see mbedtls_ecp_set_max_ops()) - * in this case you must call this function again to complete * the handshake when you're done attending other tasks. * \return #MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED if DTLS is in use * and the client did not demonstrate reachability yet - in * this case you must stop using the context (see below). * \return Another SSL error code - in this case you must stop using * the context (see below). * * \warning If this function returns something other than * \c 0, * #MBEDTLS_ERR_SSL_WANT_READ, * #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, * you must stop using the SSL context for reading or writing, * and either free it or call \c mbedtls_ssl_session_reset() * on it before re-using it for a new connection; the current * connection must be closed. * * \note If DTLS is in use, then you may choose to handle * #MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED specially for logging * purposes, as it is an expected return value rather than an * actual error, but you still need to reset/free the context. * * \note Remarks regarding event-driven DTLS: * If the function returns #MBEDTLS_ERR_SSL_WANT_READ, no datagram * from the underlying transport layer is currently being processed, * and it is safe to idle until the timer or the underlying transport * signal a new event. This is not true for a successful handshake, * in which case the datagram of the underlying transport that is * currently being processed might or might not contain further * DTLS records. */ int mbedtls_ssl_handshake( mbedtls_ssl_context *ssl ); /** * \brief Perform a single step of the SSL handshake * * \note The state of the context (ssl->state) will be at * the next state after this function returns \c 0. Do not * call this function if state is MBEDTLS_SSL_HANDSHAKE_OVER. * * \param ssl SSL context * * \return See mbedtls_ssl_handshake(). * * \warning If this function returns something other than \c 0, * #MBEDTLS_ERR_SSL_WANT_READ, #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, you must stop using * the SSL context for reading or writing, and either free it * or call \c mbedtls_ssl_session_reset() on it before * re-using it for a new connection; the current connection * must be closed. */ int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl ); #if defined(MBEDTLS_SSL_RENEGOTIATION) /** * \brief Initiate an SSL renegotiation on the running connection. * Client: perform the renegotiation right now. * Server: request renegotiation, which will be performed * during the next call to mbedtls_ssl_read() if honored by * client. * * \param ssl SSL context * * \return 0 if successful, or any mbedtls_ssl_handshake() return * value except #MBEDTLS_ERR_SSL_CLIENT_RECONNECT that can't * happen during a renegotiation. * * \warning If this function returns something other than \c 0, * #MBEDTLS_ERR_SSL_WANT_READ, #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, you must stop using * the SSL context for reading or writing, and either free it * or call \c mbedtls_ssl_session_reset() on it before * re-using it for a new connection; the current connection * must be closed. * */ int mbedtls_ssl_renegotiate( mbedtls_ssl_context *ssl ); #endif /* MBEDTLS_SSL_RENEGOTIATION */ /** * \brief Read at most 'len' application data bytes * * \param ssl SSL context * \param buf buffer that will hold the data * \param len maximum number of bytes to read * * \return The (positive) number of bytes read if successful. * \return \c 0 if the read end of the underlying transport was closed * without sending a CloseNotify beforehand, which might happen * because of various reasons (internal error of an underlying * stack, non-conformant peer not sending a CloseNotify and * such) - in this case you must stop using the context * (see below). * \return #MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY if the underlying * transport is still functional, but the peer has * acknowledged to not send anything anymore. * \return #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE * if the handshake is incomplete and waiting for data to * be available for reading from or writing to the underlying * transport - in this case you must call this function again * when the underlying transport is ready for the operation. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous * operation is in progress (see * mbedtls_ssl_conf_async_private_cb()) - in this case you * must call this function again when the operation is ready. * \return #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic * operation is in progress (see mbedtls_ecp_set_max_ops()) - * in this case you must call this function again to complete * the handshake when you're done attending other tasks. * \return #MBEDTLS_ERR_SSL_CLIENT_RECONNECT if we're at the server * side of a DTLS connection and the client is initiating a * new connection using the same source port. See below. * \return Another SSL error code - in this case you must stop using * the context (see below). * * \warning If this function returns something other than * a positive value, * #MBEDTLS_ERR_SSL_WANT_READ, * #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CLIENT_RECONNECT, * you must stop using the SSL context for reading or writing, * and either free it or call \c mbedtls_ssl_session_reset() * on it before re-using it for a new connection; the current * connection must be closed. * * \note When this function returns #MBEDTLS_ERR_SSL_CLIENT_RECONNECT * (which can only happen server-side), it means that a client * is initiating a new connection using the same source port. * You can either treat that as a connection close and wait * for the client to resend a ClientHello, or directly * continue with \c mbedtls_ssl_handshake() with the same * context (as it has been reset internally). Either way, you * must make sure this is seen by the application as a new * connection: application state, if any, should be reset, and * most importantly the identity of the client must be checked * again. WARNING: not validating the identity of the client * again, or not transmitting the new identity to the * application layer, would allow authentication bypass! * * \note Remarks regarding event-driven DTLS: * - If the function returns #MBEDTLS_ERR_SSL_WANT_READ, no datagram * from the underlying transport layer is currently being processed, * and it is safe to idle until the timer or the underlying transport * signal a new event. * - This function may return MBEDTLS_ERR_SSL_WANT_READ even if data was * initially available on the underlying transport, as this data may have * been only e.g. duplicated messages or a renegotiation request. * Therefore, you must be prepared to receive MBEDTLS_ERR_SSL_WANT_READ even * when reacting to an incoming-data event from the underlying transport. * - On success, the datagram of the underlying transport that is currently * being processed may contain further DTLS records. You should call * \c mbedtls_ssl_check_pending to check for remaining records. * */ int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len ); /** * \brief Try to write exactly 'len' application data bytes * * \warning This function will do partial writes in some cases. If the * return value is non-negative but less than length, the * function must be called again with updated arguments: * buf + ret, len - ret (if ret is the return value) until * it returns a value equal to the last 'len' argument. * * \param ssl SSL context * \param buf buffer holding the data * \param len how many bytes must be written * * \return The (non-negative) number of bytes actually written if * successful (may be less than \p len). * \return #MBEDTLS_ERR_SSL_WANT_READ or #MBEDTLS_ERR_SSL_WANT_WRITE * if the handshake is incomplete and waiting for data to * be available for reading from or writing to the underlying * transport - in this case you must call this function again * when the underlying transport is ready for the operation. * \return #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS if an asynchronous * operation is in progress (see * mbedtls_ssl_conf_async_private_cb()) - in this case you * must call this function again when the operation is ready. * \return #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS if a cryptographic * operation is in progress (see mbedtls_ecp_set_max_ops()) - * in this case you must call this function again to complete * the handshake when you're done attending other tasks. * \return Another SSL error code - in this case you must stop using * the context (see below). * * \warning If this function returns something other than * a non-negative value, * #MBEDTLS_ERR_SSL_WANT_READ, * #MBEDTLS_ERR_SSL_WANT_WRITE, * #MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS or * #MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS, * you must stop using the SSL context for reading or writing, * and either free it or call \c mbedtls_ssl_session_reset() * on it before re-using it for a new connection; the current * connection must be closed. * * \note When this function returns #MBEDTLS_ERR_SSL_WANT_WRITE/READ, * it must be called later with the *same* arguments, * until it returns a value greater that or equal to 0. When * the function returns #MBEDTLS_ERR_SSL_WANT_WRITE there may be * some partial data in the output buffer, however this is not * yet sent. * * \note If the requested length is greater than the maximum * fragment length (either the built-in limit or the one set * or negotiated with the peer), then: * - with TLS, less bytes than requested are written. * - with DTLS, MBEDTLS_ERR_SSL_BAD_INPUT_DATA is returned. * \c mbedtls_ssl_get_max_out_record_payload() may be used to * query the active maximum fragment length. * * \note Attempting to write 0 bytes will result in an empty TLS * application record being sent. */ int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ); /** * \brief Send an alert message * * \param ssl SSL context * \param level The alert level of the message * (MBEDTLS_SSL_ALERT_LEVEL_WARNING or MBEDTLS_SSL_ALERT_LEVEL_FATAL) * \param message The alert message (SSL_ALERT_MSG_*) * * \return 0 if successful, or a specific SSL error code. * * \note If this function returns something other than 0 or * MBEDTLS_ERR_SSL_WANT_READ/WRITE, you must stop using * the SSL context for reading or writing, and either free it or * call \c mbedtls_ssl_session_reset() on it before re-using it * for a new connection; the current connection must be closed. */ int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl, unsigned char level, unsigned char message ); /** * \brief Notify the peer that the connection is being closed * * \param ssl SSL context * * \return 0 if successful, or a specific SSL error code. * * \note If this function returns something other than 0 or * MBEDTLS_ERR_SSL_WANT_READ/WRITE, you must stop using * the SSL context for reading or writing, and either free it or * call \c mbedtls_ssl_session_reset() on it before re-using it * for a new connection; the current connection must be closed. */ int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl ); /** * \brief Free referenced items in an SSL context and clear memory * * \param ssl SSL context */ void mbedtls_ssl_free( mbedtls_ssl_context *ssl ); #if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION) /** * \brief Save an active connection as serialized data in a buffer. * This allows the freeing or re-using of the SSL context * while still picking up the connection later in a way that * it entirely transparent to the peer. * * \see mbedtls_ssl_context_load() * * \note This feature is currently only available under certain * conditions, see the documentation of the return value * #MBEDTLS_ERR_SSL_BAD_INPUT_DATA for details. * * \note When this function succeeds, it calls * mbedtls_ssl_session_reset() on \p ssl which as a result is * no longer associated with the connection that has been * serialized. This avoids creating copies of the connection * state. You're then free to either re-use the context * structure for a different connection, or call * mbedtls_ssl_free() on it. See the documentation of * mbedtls_ssl_session_reset() for more details. * * \param ssl The SSL context to save. On success, it is no longer * associated with the connection that has been serialized. * \param buf The buffer to write the serialized data to. It must be a * writeable buffer of at least \p buf_len bytes, or may be \c * NULL if \p buf_len is \c 0. * \param buf_len The number of bytes available for writing in \p buf. * \param olen The size in bytes of the data that has been or would have * been written. It must point to a valid \c size_t. * * \note \p olen is updated to the correct value regardless of * whether \p buf_len was large enough. This makes it possible * to determine the necessary size by calling this function * with \p buf set to \c NULL and \p buf_len to \c 0. However, * the value of \p olen is only guaranteed to be correct when * the function returns #MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL or * \c 0. If the return value is different, then the value of * \p olen is undefined. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if \p buf is too small. * \return #MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed * while reseting the context. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if a handshake is in * progress, or there is pending data for reading or sending, * or the connection does not use DTLS 1.2 with an AEAD * ciphersuite, or renegotiation is enabled. */ int mbedtls_ssl_context_save( mbedtls_ssl_context *ssl, unsigned char *buf, size_t buf_len, size_t *olen ); /** * \brief Load serialized connection data to an SSL context. * * \see mbedtls_ssl_context_save() * * \warning The same serialized data must never be loaded into more * that one context. In order to ensure that, after * successfully loading serialized data to an SSL context, you * should immediately destroy or invalidate all copies of the * serialized data that was loaded. Loading the same data in * more than one context would cause severe security failures * including but not limited to loss of confidentiality. * * \note Before calling this function, the SSL context must be * prepared in one of the two following ways. The first way is * to take a context freshly initialised with * mbedtls_ssl_init() and call mbedtls_ssl_setup() on it with * the same ::mbedtls_ssl_config structure that was used in * the original connection. The second way is to * call mbedtls_ssl_session_reset() on a context that was * previously prepared as above but used in the meantime. * Either way, you must not use the context to perform a * handshake between calling mbedtls_ssl_setup() or * mbedtls_ssl_session_reset() and calling this function. You * may however call other setter functions in that time frame * as indicated in the note below. * * \note Before or after calling this function successfully, you * also need to configure some connection-specific callbacks * and settings before you can use the connection again * (unless they were already set before calling * mbedtls_ssl_session_reset() and the values are suitable for * the present connection). Specifically, you want to call * at least mbedtls_ssl_set_bio() and * mbedtls_ssl_set_timer_cb(). All other SSL setter functions * are not necessary to call, either because they're only used * in handshakes, or because the setting is already saved. You * might choose to call them anyway, for example in order to * share code between the cases of establishing a new * connection and the case of loading an already-established * connection. * * \note If you have new information about the path MTU, you want to * call mbedtls_ssl_set_mtu() after calling this function, as * otherwise this function would overwrite your * newly-configured value with the value that was active when * the context was saved. * * \note When this function returns an error code, it calls * mbedtls_ssl_free() on \p ssl. In this case, you need to * prepare the context with the usual sequence starting with a * call to mbedtls_ssl_init() if you want to use it again. * * \param ssl The SSL context structure to be populated. It must have * been prepared as described in the note above. * \param buf The buffer holding the serialized connection data. It must * be a readable buffer of at least \p len bytes. * \param len The size of the serialized data in bytes. * * \return \c 0 if successful. * \return #MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed. * \return #MBEDTLS_ERR_SSL_VERSION_MISMATCH if the serialized data * comes from a different Mbed TLS version or build. * \return #MBEDTLS_ERR_SSL_BAD_INPUT_DATA if input data is invalid. */ int mbedtls_ssl_context_load( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len ); #endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */ /** * \brief Initialize an SSL configuration context * Just makes the context ready for * mbedtls_ssl_config_defaults() or mbedtls_ssl_config_free(). * * \note You need to call mbedtls_ssl_config_defaults() unless you * manually set all of the relevant fields yourself. * * \param conf SSL configuration context */ void mbedtls_ssl_config_init( mbedtls_ssl_config *conf ); /** * \brief Load reasonnable default SSL configuration values. * (You need to call mbedtls_ssl_config_init() first.) * * \param conf SSL configuration context * \param endpoint MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER * \param transport MBEDTLS_SSL_TRANSPORT_STREAM for TLS, or * MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS * \param preset a MBEDTLS_SSL_PRESET_XXX value * * \note See \c mbedtls_ssl_conf_transport() for notes on DTLS. * * \return 0 if successful, or * MBEDTLS_ERR_XXX_ALLOC_FAILED on memory allocation error. */ int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf, int endpoint, int transport, int preset ); /** * \brief Free an SSL configuration context * * \param conf SSL configuration context */ void mbedtls_ssl_config_free( mbedtls_ssl_config *conf ); /** * \brief Initialize SSL session structure * * \param session SSL session */ void mbedtls_ssl_session_init( mbedtls_ssl_session *session ); /** * \brief Free referenced items in an SSL session including the * peer certificate and clear memory * * \note A session object can be freed even if the SSL context * that was used to retrieve the session is still in use. * * \param session SSL session */ void mbedtls_ssl_session_free( mbedtls_ssl_session *session ); /** * \brief TLS-PRF function for key derivation. * * \param prf The tls_prf type function type to be used. * \param secret Secret for the key derivation function. * \param slen Length of the secret. * \param label String label for the key derivation function, * terminated with null character. * \param random Random bytes. * \param rlen Length of the random bytes buffer. * \param dstbuf The buffer holding the derived key. * \param dlen Length of the output buffer. * * \return 0 on success. An SSL specific error on failure. */ int mbedtls_ssl_tls_prf( const mbedtls_tls_prf_types prf, const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ); #ifdef __cplusplus } #endif #endif /* ssl.h */