/** \file ssl_helpers.h * * \brief This file contains helper functions to set up a TLS connection. */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #ifndef SSL_HELPERS_H #define SSL_HELPERS_H #include "mbedtls/build_info.h" #include #include #include #include #include #if defined(MBEDTLS_SSL_TLS_C) #include #include #include #include "test/certs.h" #if defined(MBEDTLS_SSL_CACHE_C) #include "mbedtls/ssl_cache.h" #endif #if defined(MBEDTLS_USE_PSA_CRYPTO) #define PSA_TO_MBEDTLS_ERR(status) PSA_TO_MBEDTLS_ERR_LIST(status, \ psa_to_ssl_errors, \ psa_generic_status_to_mbedtls) #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_3) #if defined(MBEDTLS_SSL_HAVE_AES) #if defined(MBEDTLS_SSL_HAVE_GCM) #if defined(MBEDTLS_MD_CAN_SHA384) #define MBEDTLS_TEST_HAS_TLS1_3_AES_256_GCM_SHA384 #endif #if defined(MBEDTLS_MD_CAN_SHA256) #define MBEDTLS_TEST_HAS_TLS1_3_AES_128_GCM_SHA256 #endif #endif /* MBEDTLS_SSL_HAVE_GCM */ #if defined(MBEDTLS_SSL_HAVE_CCM) && defined(MBEDTLS_MD_CAN_SHA256) #define MBEDTLS_TEST_HAS_TLS1_3_AES_128_CCM_SHA256 #define MBEDTLS_TEST_HAS_TLS1_3_AES_128_CCM_8_SHA256 #endif #endif /* MBEDTLS_SSL_HAVE_AES */ #if defined(MBEDTLS_SSL_HAVE_CHACHAPOLY) && defined(MBEDTLS_MD_CAN_SHA256) #define MBEDTLS_TEST_HAS_TLS1_3_CHACHA20_POLY1305_SHA256 #endif #if defined(MBEDTLS_TEST_HAS_TLS1_3_AES_256_GCM_SHA384) || \ defined(MBEDTLS_TEST_HAS_TLS1_3_AES_128_GCM_SHA256) || \ defined(MBEDTLS_TEST_HAS_TLS1_3_AES_128_CCM_SHA256) || \ defined(MBEDTLS_TEST_HAS_TLS1_3_AES_128_CCM_8_SHA256) || \ defined(MBEDTLS_TEST_HAS_TLS1_3_CHACHA20_POLY1305_SHA256) #define MBEDTLS_TEST_AT_LEAST_ONE_TLS1_3_CIPHERSUITE #endif #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */ #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) #define MBEDTLS_CAN_HANDLE_RSA_TEST_KEY #endif enum { #define MBEDTLS_SSL_TLS1_3_LABEL(name, string) \ tls13_label_ ## name, MBEDTLS_SSL_TLS1_3_LABEL_LIST #undef MBEDTLS_SSL_TLS1_3_LABEL }; #if defined(MBEDTLS_SSL_ALPN) #define MBEDTLS_TEST_MAX_ALPN_LIST_SIZE 10 #endif typedef struct mbedtls_test_ssl_log_pattern { const char *pattern; size_t counter; } mbedtls_test_ssl_log_pattern; typedef struct mbedtls_test_handshake_test_options { const char *cipher; uint16_t *group_list; mbedtls_ssl_protocol_version client_min_version; mbedtls_ssl_protocol_version client_max_version; mbedtls_ssl_protocol_version server_min_version; mbedtls_ssl_protocol_version server_max_version; mbedtls_ssl_protocol_version expected_negotiated_version; int expected_handshake_result; int expected_ciphersuite; int pk_alg; int opaque_alg; int opaque_alg2; int opaque_usage; data_t *psk_str; int dtls; int srv_auth_mode; int serialize; int mfl; int cli_msg_len; int srv_msg_len; int expected_cli_fragments; int expected_srv_fragments; int renegotiate; int legacy_renegotiation; void *srv_log_obj; void *cli_log_obj; void (*srv_log_fun)(void *, int, const char *, int, const char *); void (*cli_log_fun)(void *, int, const char *, int, const char *); int resize_buffers; int early_data; int max_early_data_size; #if defined(MBEDTLS_SSL_CACHE_C) mbedtls_ssl_cache_context *cache; #endif #if defined(MBEDTLS_SSL_ALPN) const char *alpn_list[MBEDTLS_TEST_MAX_ALPN_LIST_SIZE]; #endif } mbedtls_test_handshake_test_options; /* * Buffer structure for custom I/O callbacks. */ typedef struct mbedtls_test_ssl_buffer { size_t start; size_t content_length; size_t capacity; unsigned char *buffer; } mbedtls_test_ssl_buffer; /* * Context for a message metadata queue (fifo) that is on top of the ring buffer. */ typedef struct mbedtls_test_ssl_message_queue { size_t *messages; int pos; int num; int capacity; } mbedtls_test_ssl_message_queue; /* * Context for the I/O callbacks simulating network connection. */ #define MBEDTLS_MOCK_SOCKET_CONNECTED 1 typedef struct mbedtls_test_mock_socket { int status; mbedtls_test_ssl_buffer *input; mbedtls_test_ssl_buffer *output; struct mbedtls_test_mock_socket *peer; } mbedtls_test_mock_socket; /* Errors used in the message socket mocks */ #define MBEDTLS_TEST_ERROR_CONTEXT_ERROR -55 #define MBEDTLS_TEST_ERROR_SEND_FAILED -66 #define MBEDTLS_TEST_ERROR_RECV_FAILED -77 /* * Structure used as an addon, or a wrapper, around the mocked sockets. * Contains an input queue, to which the other socket pushes metadata, * and an output queue, to which this one pushes metadata. This context is * considered as an owner of the input queue only, which is initialized and * freed in the respective setup and free calls. */ typedef struct mbedtls_test_message_socket_context { mbedtls_test_ssl_message_queue *queue_input; mbedtls_test_ssl_message_queue *queue_output; mbedtls_test_mock_socket *socket; } mbedtls_test_message_socket_context; #if defined(MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED) /* * Structure with endpoint's certificates for SSL communication tests. */ typedef struct mbedtls_test_ssl_endpoint_certificate { mbedtls_x509_crt *ca_cert; mbedtls_x509_crt *cert; mbedtls_pk_context *pkey; } mbedtls_test_ssl_endpoint_certificate; /* * Endpoint structure for SSL communication tests. */ typedef struct mbedtls_test_ssl_endpoint { const char *name; mbedtls_ssl_context ssl; mbedtls_ssl_config conf; mbedtls_test_mock_socket socket; mbedtls_test_ssl_endpoint_certificate cert; } mbedtls_test_ssl_endpoint; #endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */ /* * Random number generator aimed for TLS unitary tests. Its main purpose is to * simplify the set-up of a random number generator for TLS * unitary tests: no need to set up a good entropy source for example. */ int mbedtls_test_random(void *p_rng, unsigned char *output, size_t output_len); /* * This function can be passed to mbedtls to receive output logs from it. In * this case, it will count the instances of a mbedtls_test_ssl_log_pattern * in the received logged messages. */ void mbedtls_test_ssl_log_analyzer(void *ctx, int level, const char *file, int line, const char *str); void mbedtls_test_init_handshake_options( mbedtls_test_handshake_test_options *opts); void mbedtls_test_free_handshake_options( mbedtls_test_handshake_test_options *opts); /* * Initialises \p buf. After calling this function it is safe to call * `mbedtls_test_ssl_buffer_free()` on \p buf. */ void mbedtls_test_ssl_buffer_init(mbedtls_test_ssl_buffer *buf); /* * Sets up \p buf. After calling this function it is safe to call * `mbedtls_test_ssl_buffer_put()` and `mbedtls_test_ssl_buffer_get()` * on \p buf. */ int mbedtls_test_ssl_buffer_setup(mbedtls_test_ssl_buffer *buf, size_t capacity); void mbedtls_test_ssl_buffer_free(mbedtls_test_ssl_buffer *buf); /* * Puts \p input_len bytes from the \p input buffer into the ring buffer \p buf. * * \p buf must have been initialized and set up by calling * `mbedtls_test_ssl_buffer_init()` and `mbedtls_test_ssl_buffer_setup()`. * * \retval \p input_len, if the data fits. * \retval 0 <= value < \p input_len, if the data does not fit. * \retval -1, if \p buf is NULL, it hasn't been set up or \p input_len is not * zero and \p input is NULL. */ int mbedtls_test_ssl_buffer_put(mbedtls_test_ssl_buffer *buf, const unsigned char *input, size_t input_len); /* * Gets \p output_len bytes from the ring buffer \p buf into the * \p output buffer. The output buffer can be NULL, in this case a part of the * ring buffer will be dropped, if the requested length is available. * * \p buf must have been initialized and set up by calling * `mbedtls_test_ssl_buffer_init()` and `mbedtls_test_ssl_buffer_setup()`. * * \retval \p output_len, if the data is available. * \retval 0 <= value < \p output_len, if the data is not available. * \retval -1, if \buf is NULL or it hasn't been set up. */ int mbedtls_test_ssl_buffer_get(mbedtls_test_ssl_buffer *buf, unsigned char *output, size_t output_len); /* * Errors used in the message transport mock tests */ #define MBEDTLS_TEST_ERROR_ARG_NULL -11 #define MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED -44 /* * Setup and free functions for the message metadata queue. * * \p capacity describes the number of message metadata chunks that can be held * within the queue. * * \retval 0, if a metadata queue of a given length can be allocated. * \retval MBEDTLS_ERR_SSL_ALLOC_FAILED, if allocation failed. */ int mbedtls_test_ssl_message_queue_setup( mbedtls_test_ssl_message_queue *queue, size_t capacity); void mbedtls_test_ssl_message_queue_free( mbedtls_test_ssl_message_queue *queue); /* * Push message length information onto the message metadata queue. * This will become the last element to leave it (fifo). * * \retval MBEDTLS_TEST_ERROR_ARG_NULL, if the queue is null. * \retval MBEDTLS_ERR_SSL_WANT_WRITE, if the queue is full. * \retval \p len, if the push was successful. */ int mbedtls_test_ssl_message_queue_push_info( mbedtls_test_ssl_message_queue *queue, size_t len); /* * Pop information about the next message length from the queue. This will be * the oldest inserted message length(fifo). \p msg_len can be null, in which * case the data will be popped from the queue but not copied anywhere. * * \retval MBEDTLS_TEST_ERROR_ARG_NULL, if the queue is null. * \retval MBEDTLS_ERR_SSL_WANT_READ, if the queue is empty. * \retval message length, if the pop was successful, up to the given \p buf_len. */ int mbedtls_test_ssl_message_queue_pop_info( mbedtls_test_ssl_message_queue *queue, size_t buf_len); /* * Setup and teardown functions for mock sockets. */ void mbedtls_test_mock_socket_init(mbedtls_test_mock_socket *socket); /* * Closes the socket \p socket. * * \p socket must have been previously initialized by calling * mbedtls_test_mock_socket_init(). * * This function frees all allocated resources and both sockets are aware of the * new connection state. * * That is, this function does not simulate half-open TCP connections and the * phenomenon that when closing a UDP connection the peer is not aware of the * connection having been closed. */ void mbedtls_test_mock_socket_close(mbedtls_test_mock_socket *socket); /* * Establishes a connection between \p peer1 and \p peer2. * * \p peer1 and \p peer2 must have been previously initialized by calling * mbedtls_test_mock_socket_init(). * * The capacities of the internal buffers are set to \p bufsize. Setting this to * the correct value allows for simulation of MTU, sanity testing the mock * implementation and mocking TCP connections with lower memory cost. */ int mbedtls_test_mock_socket_connect(mbedtls_test_mock_socket *peer1, mbedtls_test_mock_socket *peer2, size_t bufsize); /* * Callbacks for simulating blocking I/O over connection-oriented transport. */ int mbedtls_test_mock_tcp_send_b(void *ctx, const unsigned char *buf, size_t len); int mbedtls_test_mock_tcp_recv_b(void *ctx, unsigned char *buf, size_t len); /* * Callbacks for simulating non-blocking I/O over connection-oriented transport. */ int mbedtls_test_mock_tcp_send_nb(void *ctx, const unsigned char *buf, size_t len); int mbedtls_test_mock_tcp_recv_nb(void *ctx, unsigned char *buf, size_t len); void mbedtls_test_message_socket_init( mbedtls_test_message_socket_context *ctx); /* * Setup a given message socket context including initialization of * input/output queues to a chosen capacity of messages. Also set the * corresponding mock socket. * * \retval 0, if everything succeeds. * \retval MBEDTLS_ERR_SSL_ALLOC_FAILED, if allocation of a message * queue failed. */ int mbedtls_test_message_socket_setup( mbedtls_test_ssl_message_queue *queue_input, mbedtls_test_ssl_message_queue *queue_output, size_t queue_capacity, mbedtls_test_mock_socket *socket, mbedtls_test_message_socket_context *ctx); /* * Close a given message socket context, along with the socket itself. Free the * memory allocated by the input queue. */ void mbedtls_test_message_socket_close( mbedtls_test_message_socket_context *ctx); /* * Send one message through a given message socket context. * * \retval \p len, if everything succeeds. * \retval MBEDTLS_TEST_ERROR_CONTEXT_ERROR, if any of the needed context * elements or the context itself is null. * \retval MBEDTLS_TEST_ERROR_SEND_FAILED if * mbedtls_test_mock_tcp_send_b failed. * \retval MBEDTLS_ERR_SSL_WANT_WRITE, if the output queue is full. * * This function will also return any error from * mbedtls_test_ssl_message_queue_push_info. */ int mbedtls_test_mock_tcp_send_msg(void *ctx, const unsigned char *buf, size_t len); /* * Receive one message from a given message socket context and return message * length or an error. * * \retval message length, if everything succeeds. * \retval MBEDTLS_TEST_ERROR_CONTEXT_ERROR, if any of the needed context * elements or the context itself is null. * \retval MBEDTLS_TEST_ERROR_RECV_FAILED if * mbedtls_test_mock_tcp_recv_b failed. * * This function will also return any error other than * MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED from test_ssl_message_queue_peek_info. */ int mbedtls_test_mock_tcp_recv_msg(void *ctx, unsigned char *buf, size_t buf_len); #if defined(MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED) /* * Initializes \p ep_cert structure and assigns it to endpoint * represented by \p ep. * * \retval 0 on success, otherwise error code. */ int mbedtls_test_ssl_endpoint_certificate_init(mbedtls_test_ssl_endpoint *ep, int pk_alg, int opaque_alg, int opaque_alg2, int opaque_usage); /* * Initializes \p ep structure. It is important to call * `mbedtls_test_ssl_endpoint_free()` after calling this function * even if it fails. * * \p endpoint_type must be set as MBEDTLS_SSL_IS_SERVER or * MBEDTLS_SSL_IS_CLIENT. * \p pk_alg the algorithm to use, currently only MBEDTLS_PK_RSA and * MBEDTLS_PK_ECDSA are supported. * \p dtls_context - in case of DTLS - this is the context handling metadata. * \p input_queue - used only in case of DTLS. * \p output_queue - used only in case of DTLS. * * \retval 0 on success, otherwise error code. */ int mbedtls_test_ssl_endpoint_init( mbedtls_test_ssl_endpoint *ep, int endpoint_type, mbedtls_test_handshake_test_options *options, mbedtls_test_message_socket_context *dtls_context, mbedtls_test_ssl_message_queue *input_queue, mbedtls_test_ssl_message_queue *output_queue); /* * Deinitializes endpoint represented by \p ep. */ void mbedtls_test_ssl_endpoint_free( mbedtls_test_ssl_endpoint *ep, mbedtls_test_message_socket_context *context); /* * This function moves ssl handshake from \p ssl to prescribed \p state. * /p second_ssl is used as second endpoint and their sockets have to be * connected before calling this function. * * \retval 0 on success, otherwise error code. */ int mbedtls_test_move_handshake_to_state(mbedtls_ssl_context *ssl, mbedtls_ssl_context *second_ssl, int state); #endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */ /* * Helper function setting up inverse record transformations * using given cipher, hash, EtM mode, authentication tag length, * and version. */ #define CHK(x) \ do \ { \ if (!(x)) \ { \ ret = -1; \ goto cleanup; \ } \ } while (0) #if MBEDTLS_SSL_CID_OUT_LEN_MAX > MBEDTLS_SSL_CID_IN_LEN_MAX #define SSL_CID_LEN_MIN MBEDTLS_SSL_CID_IN_LEN_MAX #else #define SSL_CID_LEN_MIN MBEDTLS_SSL_CID_OUT_LEN_MAX #endif #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ defined(MBEDTLS_SSL_HAVE_CBC) && defined(MBEDTLS_SSL_HAVE_AES) int mbedtls_test_psa_cipher_encrypt_helper(mbedtls_ssl_transform *transform, const unsigned char *iv, size_t iv_len, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen); #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && MBEDTLS_SSL_HAVE_CBC && MBEDTLS_SSL_HAVE_AES */ int mbedtls_test_ssl_build_transforms(mbedtls_ssl_transform *t_in, mbedtls_ssl_transform *t_out, int cipher_type, int hash_id, int etm, int tag_mode, mbedtls_ssl_protocol_version tls_version, size_t cid0_len, size_t cid1_len); #if defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC) /** * \param[in,out] record The record to prepare. * It must contain the data to MAC at offset * `record->data_offset`, of length * `record->data_length`. * On success, write the MAC immediately * after the data and increment * `record->data_length` accordingly. * \param[in,out] transform_out The out transform, typically prepared by * mbedtls_test_ssl_build_transforms(). * Its HMAC context may be used. Other than that * it is treated as an input parameter. * * \return 0 on success, an `MBEDTLS_ERR_xxx` error code * or -1 on error. */ int mbedtls_test_ssl_prepare_record_mac(mbedtls_record *record, mbedtls_ssl_transform *transform_out); #endif /* MBEDTLS_SSL_SOME_SUITES_USE_MAC */ /* * Populate a session structure for serialization tests. * Choose dummy values, mostly non-0 to distinguish from the init default. */ int mbedtls_test_ssl_tls12_populate_session(mbedtls_ssl_session *session, int ticket_len, int endpoint_type, const char *crt_file); #if defined(MBEDTLS_SSL_PROTO_TLS1_3) int mbedtls_test_ssl_tls13_populate_session(mbedtls_ssl_session *session, int ticket_len, int endpoint_type); #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */ /* * Perform data exchanging between \p ssl_1 and \p ssl_2 and check if the * message was sent in the correct number of fragments. * * /p ssl_1 and /p ssl_2 Endpoints represented by mbedtls_ssl_context. Both * of them must be initialized and connected * beforehand. * /p msg_len_1 and /p msg_len_2 specify the size of the message to send. * /p expected_fragments_1 and /p expected_fragments_2 determine in how many * fragments the message should be sent. * expected_fragments is 0: can be used for DTLS testing while the message * size is larger than MFL. In that case the message * cannot be fragmented and sent to the second * endpoint. * This value can be used for negative tests. * expected_fragments is 1: can be used for TLS/DTLS testing while the * message size is below MFL * expected_fragments > 1: can be used for TLS testing while the message * size is larger than MFL * * \retval 0 on success, otherwise error code. */ int mbedtls_test_ssl_exchange_data( mbedtls_ssl_context *ssl_1, int msg_len_1, const int expected_fragments_1, mbedtls_ssl_context *ssl_2, int msg_len_2, const int expected_fragments_2); #if defined(MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED) void mbedtls_test_ssl_perform_handshake( mbedtls_test_handshake_test_options *options); #endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */ #if defined(MBEDTLS_TEST_HOOKS) /* * Tweak vector lengths in a TLS 1.3 Certificate message * * \param[in] buf Buffer containing the Certificate message to tweak * \param[in]]out] end End of the buffer to parse * \param tweak Tweak identifier (from 1 to the number of tweaks). * \param[out] expected_result Error code expected from the parsing function * \param[out] args Arguments of the MBEDTLS_SSL_CHK_BUF_READ_PTR call that * is expected to fail. All zeroes if no * MBEDTLS_SSL_CHK_BUF_READ_PTR failure is expected. */ int mbedtls_test_tweak_tls13_certificate_msg_vector_len( unsigned char *buf, unsigned char **end, int tweak, int *expected_result, mbedtls_ssl_chk_buf_ptr_args *args); #endif /* MBEDTLS_TEST_HOOKS */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) int mbedtls_test_ticket_write( void *p_ticket, const mbedtls_ssl_session *session, unsigned char *start, const unsigned char *end, size_t *tlen, uint32_t *ticket_lifetime); int mbedtls_test_ticket_parse(void *p_ticket, mbedtls_ssl_session *session, unsigned char *buf, size_t len); #endif /* MBEDTLS_SSL_SESSION_TICKETS */ #if defined(MBEDTLS_SSL_CLI_C) && defined(MBEDTLS_SSL_SRV_C) && \ defined(MBEDTLS_SSL_PROTO_TLS1_3) && defined(MBEDTLS_SSL_SESSION_TICKETS) && \ defined(MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED) int mbedtls_test_get_tls13_ticket( mbedtls_test_handshake_test_options *client_options, mbedtls_test_handshake_test_options *server_options, mbedtls_ssl_session *session); #endif #define ECJPAKE_TEST_PWD "bla" #if defined(MBEDTLS_USE_PSA_CRYPTO) #define ECJPAKE_TEST_SET_PASSWORD(exp_ret_val) \ ret = (use_opaque_arg) ? \ mbedtls_ssl_set_hs_ecjpake_password_opaque(&ssl, pwd_slot) : \ mbedtls_ssl_set_hs_ecjpake_password(&ssl, pwd_string, pwd_len); \ TEST_EQUAL(ret, exp_ret_val) #else #define ECJPAKE_TEST_SET_PASSWORD(exp_ret_val) \ ret = mbedtls_ssl_set_hs_ecjpake_password(&ssl, \ pwd_string, pwd_len); \ TEST_EQUAL(ret, exp_ret_val) #endif /* MBEDTLS_USE_PSA_CRYPTO */ #define TEST_AVAILABLE_ECC(tls_id_, group_id_, psa_family_, psa_bits_) \ TEST_EQUAL(mbedtls_ssl_get_ecp_group_id_from_tls_id(tls_id_), \ group_id_); \ TEST_EQUAL(mbedtls_ssl_get_tls_id_from_ecp_group_id(group_id_), \ tls_id_); \ TEST_EQUAL(mbedtls_ssl_get_psa_curve_info_from_tls_id(tls_id_, \ &psa_type, &psa_bits), PSA_SUCCESS); \ TEST_EQUAL(psa_family_, PSA_KEY_TYPE_ECC_GET_FAMILY(psa_type)); \ TEST_EQUAL(psa_bits_, psa_bits); #define TEST_UNAVAILABLE_ECC(tls_id_, group_id_, psa_family_, psa_bits_) \ TEST_EQUAL(mbedtls_ssl_get_ecp_group_id_from_tls_id(tls_id_), \ MBEDTLS_ECP_DP_NONE); \ TEST_EQUAL(mbedtls_ssl_get_tls_id_from_ecp_group_id(group_id_), \ 0); \ TEST_EQUAL(mbedtls_ssl_get_psa_curve_info_from_tls_id(tls_id_, \ &psa_type, &psa_bits), \ PSA_ERROR_NOT_SUPPORTED); #endif /* MBEDTLS_SSL_TLS_C */ #endif /* SSL_HELPERS_H */