/** * \file asn1write.h * * \brief ASN.1 buffer writing functionality */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */ #ifndef MBEDTLS_ASN1_WRITE_H #define MBEDTLS_ASN1_WRITE_H #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #include "mbedtls/asn1.h" #define MBEDTLS_ASN1_CHK_ADD(g, f) \ do \ { \ if ((ret = (f)) < 0) \ return ret; \ else \ (g) += ret; \ } while (0) #ifdef __cplusplus extern "C" { #endif /** * \brief Write a length field in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param len The length value to write. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_len(unsigned char **p, unsigned char *start, size_t len); /** * \brief Write an ASN.1 tag in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param tag The tag to write. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_tag(unsigned char **p, unsigned char *start, unsigned char tag); /** * \brief Write raw buffer data. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param buf The data buffer to write. * \param size The length of the data buffer. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_raw_buffer(unsigned char **p, unsigned char *start, const unsigned char *buf, size_t size); #if defined(MBEDTLS_BIGNUM_C) /** * \brief Write an arbitrary-precision number (#MBEDTLS_ASN1_INTEGER) * in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param X The MPI to write. * It must be non-negative. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_mpi(unsigned char **p, unsigned char *start, const mbedtls_mpi *X); #endif /* MBEDTLS_BIGNUM_C */ /** * \brief Write a NULL tag (#MBEDTLS_ASN1_NULL) with zero data * in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_null(unsigned char **p, unsigned char *start); /** * \brief Write an OID tag (#MBEDTLS_ASN1_OID) and data * in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param oid The OID to write. * \param oid_len The length of the OID. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_oid(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len); /** * \brief Write an AlgorithmIdentifier sequence in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param oid The OID of the algorithm to write. * \param oid_len The length of the algorithm's OID. * \param par_len The length of the parameters, which must be already written. * If 0, NULL parameters are added * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_algorithm_identifier(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, size_t par_len); /** * \brief Write an AlgorithmIdentifier sequence in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param oid The OID of the algorithm to write. * \param oid_len The length of the algorithm's OID. * \param par_len The length of the parameters, which must be already written. * \param has_par If there are any parameters. If 0, par_len must be 0. If 1 * and \p par_len is 0, NULL parameters are added. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_algorithm_identifier_ext(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, size_t par_len, int has_par); /** * \brief Write a boolean tag (#MBEDTLS_ASN1_BOOLEAN) and value * in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param boolean The boolean value to write, either \c 0 or \c 1. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_bool(unsigned char **p, unsigned char *start, int boolean); /** * \brief Write an int tag (#MBEDTLS_ASN1_INTEGER) and value * in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param val The integer value to write. * It must be non-negative. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_int(unsigned char **p, unsigned char *start, int val); /** * \brief Write an enum tag (#MBEDTLS_ASN1_ENUMERATED) and value * in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param val The integer value to write. * * \return The number of bytes written to \p p on success. * \return A negative \c MBEDTLS_ERR_ASN1_XXX error code on failure. */ int mbedtls_asn1_write_enum(unsigned char **p, unsigned char *start, int val); /** * \brief Write a string in ASN.1 format using a specific * string encoding tag. * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param tag The string encoding tag to write, e.g. * #MBEDTLS_ASN1_UTF8_STRING. * \param text The string to write. * \param text_len The length of \p text in bytes (which might * be strictly larger than the number of characters). * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_tagged_string(unsigned char **p, unsigned char *start, int tag, const char *text, size_t text_len); /** * \brief Write a string in ASN.1 format using the PrintableString * string encoding tag (#MBEDTLS_ASN1_PRINTABLE_STRING). * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param text The string to write. * \param text_len The length of \p text in bytes (which might * be strictly larger than the number of characters). * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_printable_string(unsigned char **p, unsigned char *start, const char *text, size_t text_len); /** * \brief Write a UTF8 string in ASN.1 format using the UTF8String * string encoding tag (#MBEDTLS_ASN1_UTF8_STRING). * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param text The string to write. * \param text_len The length of \p text in bytes (which might * be strictly larger than the number of characters). * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_utf8_string(unsigned char **p, unsigned char *start, const char *text, size_t text_len); /** * \brief Write a string in ASN.1 format using the IA5String * string encoding tag (#MBEDTLS_ASN1_IA5_STRING). * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param text The string to write. * \param text_len The length of \p text in bytes (which might * be strictly larger than the number of characters). * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_ia5_string(unsigned char **p, unsigned char *start, const char *text, size_t text_len); /** * \brief Write a bitstring tag (#MBEDTLS_ASN1_BIT_STRING) and * value in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param buf The bitstring to write. * \param bits The total number of bits in the bitstring. * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_bitstring(unsigned char **p, unsigned char *start, const unsigned char *buf, size_t bits); /** * \brief This function writes a named bitstring tag * (#MBEDTLS_ASN1_BIT_STRING) and value in ASN.1 format. * * As stated in RFC 5280 Appendix B, trailing zeroes are * omitted when encoding named bitstrings in DER. * * \note This function works backwards within the data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer which is used for bounds-checking. * \param buf The bitstring to write. * \param bits The total number of bits in the bitstring. * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_named_bitstring(unsigned char **p, unsigned char *start, const unsigned char *buf, size_t bits); /** * \brief Write an octet string tag (#MBEDTLS_ASN1_OCTET_STRING) * and value in ASN.1 format. * * \note This function works backwards in data buffer. * * \param p The reference to the current position pointer. * \param start The start of the buffer, for bounds-checking. * \param buf The buffer holding the data to write. * \param size The length of the data buffer \p buf. * * \return The number of bytes written to \p p on success. * \return A negative error code on failure. */ int mbedtls_asn1_write_octet_string(unsigned char **p, unsigned char *start, const unsigned char *buf, size_t size); /** * \brief Create or find a specific named_data entry for writing in a * sequence or list based on the OID. If not already in there, * a new entry is added to the head of the list. * Warning: Destructive behaviour for the val data! * * \param list The pointer to the location of the head of the list to seek * through (will be updated in case of a new entry). * \param oid The OID to look for. * \param oid_len The size of the OID. * \param val The associated data to store. If this is \c NULL, * no data is copied to the new or existing buffer. * \param val_len The minimum length of the data buffer needed. * If this is 0, do not allocate a buffer for the associated * data. * If the OID was already present, enlarge, shrink or free * the existing buffer to fit \p val_len. * * \return A pointer to the new / existing entry on success. * \return \c NULL if if there was a memory allocation error. */ mbedtls_asn1_named_data *mbedtls_asn1_store_named_data(mbedtls_asn1_named_data **list, const char *oid, size_t oid_len, const unsigned char *val, size_t val_len); #ifdef __cplusplus } #endif #endif /* MBEDTLS_ASN1_WRITE_H */