/** * \file pk.h * * \brief Public Key abstraction layer */ /* * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * 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. * * This file is part of mbed TLS (https://tls.mbed.org) */ #ifndef MBEDTLS_PK_H #define MBEDTLS_PK_H #if !defined(MBEDTLS_CONFIG_FILE) #include "config.h" #else #include MBEDTLS_CONFIG_FILE #endif #include "md.h" #if defined(MBEDTLS_RSA_C) #include "rsa.h" #endif #if defined(MBEDTLS_ECP_C) #include "ecp.h" #endif #if defined(MBEDTLS_ECDSA_C) #include "ecdsa.h" #endif #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \ !defined(inline) && !defined(__cplusplus) #define inline __inline #endif #define MBEDTLS_ERR_PK_ALLOC_FAILED -0x3F80 /**< Memory allocation failed. */ #define MBEDTLS_ERR_PK_TYPE_MISMATCH -0x3F00 /**< Type mismatch, eg attempt to encrypt with an ECDSA key */ #define MBEDTLS_ERR_PK_BAD_INPUT_DATA -0x3E80 /**< Bad input parameters to function. */ #define MBEDTLS_ERR_PK_FILE_IO_ERROR -0x3E00 /**< Read/write of file failed. */ #define MBEDTLS_ERR_PK_KEY_INVALID_VERSION -0x3D80 /**< Unsupported key version */ #define MBEDTLS_ERR_PK_KEY_INVALID_FORMAT -0x3D00 /**< Invalid key tag or value. */ #define MBEDTLS_ERR_PK_UNKNOWN_PK_ALG -0x3C80 /**< Key algorithm is unsupported (only RSA and EC are supported). */ #define MBEDTLS_ERR_PK_PASSWORD_REQUIRED -0x3C00 /**< Private key password can't be empty. */ #define MBEDTLS_ERR_PK_PASSWORD_MISMATCH -0x3B80 /**< Given private key password does not allow for correct decryption. */ #define MBEDTLS_ERR_PK_INVALID_PUBKEY -0x3B00 /**< The pubkey tag or value is invalid (only RSA and EC are supported). */ #define MBEDTLS_ERR_PK_INVALID_ALG -0x3A80 /**< The algorithm tag or value is invalid. */ #define MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE -0x3A00 /**< Elliptic curve is unsupported (only NIST curves are supported). */ #define MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE -0x3980 /**< Unavailable feature, e.g. RSA disabled for RSA key. */ #define MBEDTLS_ERR_PK_SIG_LEN_MISMATCH -0x3900 /**< The buffer contains a valid signature followed by more data. */ /* MBEDTLS_ERR_PK_HW_ACCEL_FAILED is deprecated and should not be used. */ #define MBEDTLS_ERR_PK_HW_ACCEL_FAILED -0x3880 /**< PK hardware accelerator failed. */ #ifdef __cplusplus extern "C" { #endif /** * \brief Public key types */ typedef enum { MBEDTLS_PK_NONE=0, MBEDTLS_PK_RSA, MBEDTLS_PK_ECKEY, MBEDTLS_PK_ECKEY_DH, MBEDTLS_PK_ECDSA, MBEDTLS_PK_RSA_ALT, MBEDTLS_PK_RSASSA_PSS, } mbedtls_pk_type_t; /** * \brief Options for RSASSA-PSS signature verification. * See \c mbedtls_rsa_rsassa_pss_verify_ext() */ typedef struct mbedtls_pk_rsassa_pss_options { mbedtls_md_type_t mgf1_hash_id; int expected_salt_len; } mbedtls_pk_rsassa_pss_options; /** * \brief Types for interfacing with the debug module */ typedef enum { MBEDTLS_PK_DEBUG_NONE = 0, MBEDTLS_PK_DEBUG_MPI, MBEDTLS_PK_DEBUG_ECP, } mbedtls_pk_debug_type; /** * \brief Item to send to the debug module */ typedef struct mbedtls_pk_debug_item { mbedtls_pk_debug_type type; const char *name; void *value; } mbedtls_pk_debug_item; /** Maximum number of item send for debugging, plus 1 */ #define MBEDTLS_PK_DEBUG_MAX_ITEMS 3 /** * \brief Public key information and operations */ typedef struct mbedtls_pk_info_t mbedtls_pk_info_t; /** * \brief Public key container */ typedef struct mbedtls_pk_context { const mbedtls_pk_info_t * pk_info; /**< Public key information */ void * pk_ctx; /**< Underlying public key context */ } mbedtls_pk_context; #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) /** * \brief Context for resuming operations */ typedef struct { const mbedtls_pk_info_t * pk_info; /**< Public key information */ void * rs_ctx; /**< Underlying restart context */ } mbedtls_pk_restart_ctx; #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */ /* Now we can declare functions that take a pointer to that */ typedef void mbedtls_pk_restart_ctx; #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */ #if defined(MBEDTLS_RSA_C) /** * Quick access to an RSA context inside a PK context. * * \warning You must make sure the PK context actually holds an RSA context * before using this function! */ static inline mbedtls_rsa_context *mbedtls_pk_rsa( const mbedtls_pk_context pk ) { return( (mbedtls_rsa_context *) (pk).pk_ctx ); } #endif /* MBEDTLS_RSA_C */ #if defined(MBEDTLS_ECP_C) /** * Quick access to an EC context inside a PK context. * * \warning You must make sure the PK context actually holds an EC context * before using this function! */ static inline mbedtls_ecp_keypair *mbedtls_pk_ec( const mbedtls_pk_context pk ) { return( (mbedtls_ecp_keypair *) (pk).pk_ctx ); } #endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT) /** * \brief Types for RSA-alt abstraction */ typedef int (*mbedtls_pk_rsa_alt_decrypt_func)( void *ctx, int mode, size_t *olen, const unsigned char *input, unsigned char *output, size_t output_max_len ); typedef int (*mbedtls_pk_rsa_alt_sign_func)( void *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, mbedtls_md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, unsigned char *sig ); typedef size_t (*mbedtls_pk_rsa_alt_key_len_func)( void *ctx ); #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */ /** * \brief Return information associated with the given PK type * * \param pk_type PK type to search for. * * \return The PK info associated with the type or NULL if not found. */ const mbedtls_pk_info_t *mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type ); /** * \brief Initialize a #mbedtls_pk_context (as NONE). * * \param ctx The context to initialize. * This must not be \c NULL. */ void mbedtls_pk_init( mbedtls_pk_context *ctx ); /** * \brief Free the components of a #mbedtls_pk_context. * * \param ctx The context to clear. It must have been initialized. * If this is \c NULL, this function does nothing. */ void mbedtls_pk_free( mbedtls_pk_context *ctx ); #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) /** * \brief Initialize a restart context * * \param ctx The context to initialize. * This must not be \c NULL. */ void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx ); /** * \brief Free the components of a restart context * * \param ctx The context to clear. It must have been initialized. * If this is \c NULL, this function does nothing. */ void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx ); #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */ /** * \brief Initialize a PK context with the information given * and allocates the type-specific PK subcontext. * * \param ctx Context to initialize. It must not have been set * up yet (type #MBEDTLS_PK_NONE). * \param info Information to use * * \return 0 on success, * MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input, * MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure. * * \note For contexts holding an RSA-alt key, use * \c mbedtls_pk_setup_rsa_alt() instead. */ int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info ); #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT) /** * \brief Initialize an RSA-alt context * * \param ctx Context to initialize. It must not have been set * up yet (type #MBEDTLS_PK_NONE). * \param key RSA key pointer * \param decrypt_func Decryption function * \param sign_func Signing function * \param key_len_func Function returning key length in bytes * * \return 0 on success, or MBEDTLS_ERR_PK_BAD_INPUT_DATA if the * context wasn't already initialized as RSA_ALT. * * \note This function replaces \c mbedtls_pk_setup() for RSA-alt. */ int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key, mbedtls_pk_rsa_alt_decrypt_func decrypt_func, mbedtls_pk_rsa_alt_sign_func sign_func, mbedtls_pk_rsa_alt_key_len_func key_len_func ); #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */ /** * \brief Get the size in bits of the underlying key * * \param ctx The context to query. It must have been initialized. * * \return Key size in bits, or 0 on error */ size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx ); /** * \brief Get the length in bytes of the underlying key * * \param ctx The context to query. It must have been initialized. * * \return Key length in bytes, or 0 on error */ static inline size_t mbedtls_pk_get_len( const mbedtls_pk_context *ctx ) { return( ( mbedtls_pk_get_bitlen( ctx ) + 7 ) / 8 ); } /** * \brief Tell if a context can do the operation given by type * * \param ctx The context to query. It must have been initialized. * \param type The desired type. * * \return 1 if the context can do operations on the given type. * \return 0 if the context cannot do the operations on the given * type. This is always the case for a context that has * been initialized but not set up, or that has been * cleared with mbedtls_pk_free(). */ int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type ); /** * \brief Verify signature (including padding if relevant). * * \param ctx The PK context to use. It must have been set up. * \param md_alg Hash algorithm used (see notes) * \param hash Hash of the message to sign * \param hash_len Hash length or 0 (see notes) * \param sig Signature to verify * \param sig_len Signature length * * \return 0 on success (signature is valid), * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid * signature in sig but its length is less than \p siglen, * or a specific error code. * * \note For RSA keys, the default padding type is PKCS#1 v1.5. * Use \c mbedtls_pk_verify_ext( MBEDTLS_PK_RSASSA_PSS, ... ) * to verify RSASSA_PSS signatures. * * \note If hash_len is 0, then the length associated with md_alg * is used instead, or an error returned if it is invalid. * * \note md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0 */ int mbedtls_pk_verify( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len, const unsigned char *sig, size_t sig_len ); /** * \brief Restartable version of \c mbedtls_pk_verify() * * \note Performs the same job as \c mbedtls_pk_verify(), but can * return early and restart according to the limit set with * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC * operations. For RSA, same as \c mbedtls_pk_verify(). * * \param ctx The PK context to use. It must have been set up. * \param md_alg Hash algorithm used (see notes) * \param hash Hash of the message to sign * \param hash_len Hash length or 0 (see notes) * \param sig Signature to verify * \param sig_len Signature length * \param rs_ctx Restart context (NULL to disable restart) * * \return See \c mbedtls_pk_verify(), or * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of * operations was reached: see \c mbedtls_ecp_set_max_ops(). */ int mbedtls_pk_verify_restartable( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len, const unsigned char *sig, size_t sig_len, mbedtls_pk_restart_ctx *rs_ctx ); /** * \brief Verify signature, with options. * (Includes verification of the padding depending on type.) * * \param type Signature type (inc. possible padding type) to verify * \param options Pointer to type-specific options, or NULL * \param ctx The PK context to use. It must have been set up. * \param md_alg Hash algorithm used (see notes) * \param hash Hash of the message to sign * \param hash_len Hash length or 0 (see notes) * \param sig Signature to verify * \param sig_len Signature length * * \return 0 on success (signature is valid), * #MBEDTLS_ERR_PK_TYPE_MISMATCH if the PK context can't be * used for this type of signatures, * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid * signature in sig but its length is less than \p siglen, * or a specific error code. * * \note If hash_len is 0, then the length associated with md_alg * is used instead, or an error returned if it is invalid. * * \note md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0 * * \note If type is MBEDTLS_PK_RSASSA_PSS, then options must point * to a mbedtls_pk_rsassa_pss_options structure, * otherwise it must be NULL. */ int mbedtls_pk_verify_ext( mbedtls_pk_type_t type, const void *options, mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len, const unsigned char *sig, size_t sig_len ); /** * \brief Make signature, including padding if relevant. * * \param ctx The PK context to use. It must have been set up * with a private key. * \param md_alg Hash algorithm used (see notes) * \param hash Hash of the message to sign * \param hash_len Hash length or 0 (see notes) * \param sig Place to write the signature * \param sig_len Number of bytes written * \param f_rng RNG function * \param p_rng RNG parameter * * \return 0 on success, or a specific error code. * * \note For RSA keys, the default padding type is PKCS#1 v1.5. * There is no interface in the PK module to make RSASSA-PSS * signatures yet. * * \note If hash_len is 0, then the length associated with md_alg * is used instead, or an error returned if it is invalid. * * \note For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0. * For ECDSA, md_alg may never be MBEDTLS_MD_NONE. * * \note In order to ensure enough space for the signature, the * \p sig buffer size must be of at least * `max(MBEDTLS_ECDSA_MAX_LEN, MBEDTLS_MPI_MAX_SIZE)` bytes. */ int mbedtls_pk_sign( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len, unsigned char *sig, size_t *sig_len, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); /** * \brief Restartable version of \c mbedtls_pk_sign() * * \note Performs the same job as \c mbedtls_pk_sign(), but can * return early and restart according to the limit set with * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC * operations. For RSA, same as \c mbedtls_pk_sign(). * * \note In order to ensure enough space for the signature, the * \p sig buffer size must be of at least * `max(MBEDTLS_ECDSA_MAX_LEN, MBEDTLS_MPI_MAX_SIZE)` bytes. * * \param ctx The PK context to use. It must have been set up * with a private key. * \param md_alg Hash algorithm used (see notes) * \param hash Hash of the message to sign * \param hash_len Hash length or 0 (see notes) * \param sig Place to write the signature * \param sig_len Number of bytes written * \param f_rng RNG function * \param p_rng RNG parameter * \param rs_ctx Restart context (NULL to disable restart) * * \return See \c mbedtls_pk_sign(), or * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of * operations was reached: see \c mbedtls_ecp_set_max_ops(). */ int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len, unsigned char *sig, size_t *sig_len, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, mbedtls_pk_restart_ctx *rs_ctx ); /** * \brief Decrypt message (including padding if relevant). * * \param ctx The PK context to use. It must have been set up * with a private key. * \param input Input to decrypt * \param ilen Input size * \param output Decrypted output * \param olen Decrypted message length * \param osize Size of the output buffer * \param f_rng RNG function * \param p_rng RNG parameter * * \note For RSA keys, the default padding type is PKCS#1 v1.5. * * \return 0 on success, or a specific error code. */ int mbedtls_pk_decrypt( mbedtls_pk_context *ctx, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen, size_t osize, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); /** * \brief Encrypt message (including padding if relevant). * * \param ctx The PK context to use. It must have been set up. * \param input Message to encrypt * \param ilen Message size * \param output Encrypted output * \param olen Encrypted output length * \param osize Size of the output buffer * \param f_rng RNG function * \param p_rng RNG parameter * * \note For RSA keys, the default padding type is PKCS#1 v1.5. * * \return 0 on success, or a specific error code. */ int mbedtls_pk_encrypt( mbedtls_pk_context *ctx, const unsigned char *input, size_t ilen, unsigned char *output, size_t *olen, size_t osize, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ); /** * \brief Check if a public-private pair of keys matches. * * \param pub Context holding a public key. * \param prv Context holding a private (and public) key. * * \return 0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA */ int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_context *prv ); /** * \brief Export debug information * * \param ctx The PK context to use. It must have been initialized. * \param items Place to write debug items * * \return 0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA */ int mbedtls_pk_debug( const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items ); /** * \brief Access the type name * * \param ctx The PK context to use. It must have been initialized. * * \return Type name on success, or "invalid PK" */ const char * mbedtls_pk_get_name( const mbedtls_pk_context *ctx ); /** * \brief Get the key type * * \param ctx The PK context to use. It must have been initialized. * * \return Type on success. * \return #MBEDTLS_PK_NONE for a context that has not been set up. */ mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx ); #if defined(MBEDTLS_PK_PARSE_C) /** \ingroup pk_module */ /** * \brief Parse a private key in PEM or DER format * * \param ctx The PK context to fill. It must have been initialized * but not set up. * \param key Input buffer to parse. * The buffer must contain the input exactly, with no * extra trailing material. For PEM, the buffer must * contain a null-terminated string. * \param keylen Size of \b key in bytes. * For PEM data, this includes the terminating null byte, * so \p keylen must be equal to `strlen(key) + 1`. * \param pwd Optional password for decryption. * Pass \c NULL if expecting a non-encrypted key. * Pass a string of \p pwdlen bytes if expecting an encrypted * key; a non-encrypted key will also be accepted. * The empty password is not supported. * \param pwdlen Size of the password in bytes. * Ignored if \p pwd is \c NULL. * * \note On entry, ctx must be empty, either freshly initialised * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a * specific key type, check the result with mbedtls_pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int mbedtls_pk_parse_key( mbedtls_pk_context *ctx, const unsigned char *key, size_t keylen, const unsigned char *pwd, size_t pwdlen ); /** \ingroup pk_module */ /** * \brief Parse a public key in PEM or DER format * * \param ctx The PK context to fill. It must have been initialized * but not set up. * \param key Input buffer to parse. * The buffer must contain the input exactly, with no * extra trailing material. For PEM, the buffer must * contain a null-terminated string. * \param keylen Size of \b key in bytes. * For PEM data, this includes the terminating null byte, * so \p keylen must be equal to `strlen(key) + 1`. * * \note On entry, ctx must be empty, either freshly initialised * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a * specific key type, check the result with mbedtls_pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx, const unsigned char *key, size_t keylen ); #if defined(MBEDTLS_FS_IO) /** \ingroup pk_module */ /** * \brief Load and parse a private key * * \param ctx The PK context to fill. It must have been initialized * but not set up. * \param path filename to read the private key from * \param password Optional password to decrypt the file. * Pass \c NULL if expecting a non-encrypted key. * Pass a null-terminated string if expecting an encrypted * key; a non-encrypted key will also be accepted. * The empty password is not supported. * * \note On entry, ctx must be empty, either freshly initialised * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a * specific key type, check the result with mbedtls_pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx, const char *path, const char *password ); /** \ingroup pk_module */ /** * \brief Load and parse a public key * * \param ctx The PK context to fill. It must have been initialized * but not set up. * \param path filename to read the public key from * * \note On entry, ctx must be empty, either freshly initialised * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If * you need a specific key type, check the result with * mbedtls_pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path ); #endif /* MBEDTLS_FS_IO */ #endif /* MBEDTLS_PK_PARSE_C */ #if defined(MBEDTLS_PK_WRITE_C) /** * \brief Write a private key to a PKCS#1 or SEC1 DER structure * Note: data is written at the end of the buffer! Use the * return value to determine where you should start * using the buffer * * \param ctx PK context which must contain a valid private key. * \param buf buffer to write to * \param size size of the buffer * * \return length of data written if successful, or a specific * error code */ int mbedtls_pk_write_key_der( mbedtls_pk_context *ctx, unsigned char *buf, size_t size ); /** * \brief Write a public key to a SubjectPublicKeyInfo DER structure * Note: data is written at the end of the buffer! Use the * return value to determine where you should start * using the buffer * * \param ctx PK context which must contain a valid public or private key. * \param buf buffer to write to * \param size size of the buffer * * \return length of data written if successful, or a specific * error code */ int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *ctx, unsigned char *buf, size_t size ); #if defined(MBEDTLS_PEM_WRITE_C) /** * \brief Write a public key to a PEM string * * \param ctx PK context which must contain a valid public or private key. * \param buf Buffer to write to. The output includes a * terminating null byte. * \param size Size of the buffer in bytes. * * \return 0 if successful, or a specific error code */ int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_t size ); /** * \brief Write a private key to a PKCS#1 or SEC1 PEM string * * \param ctx PK context which must contain a valid private key. * \param buf Buffer to write to. The output includes a * terminating null byte. * \param size Size of the buffer in bytes. * * \return 0 if successful, or a specific error code */ int mbedtls_pk_write_key_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_t size ); #endif /* MBEDTLS_PEM_WRITE_C */ #endif /* MBEDTLS_PK_WRITE_C */ /* * WARNING: Low-level functions. You probably do not want to use these unless * you are certain you do ;) */ #if defined(MBEDTLS_PK_PARSE_C) /** * \brief Parse a SubjectPublicKeyInfo DER structure * * \param p the position in the ASN.1 data * \param end end of the buffer * \param pk The PK context to fill. It must have been initialized * but not set up. * * \return 0 if successful, or a specific PK error code */ int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end, mbedtls_pk_context *pk ); #endif /* MBEDTLS_PK_PARSE_C */ #if defined(MBEDTLS_PK_WRITE_C) /** * \brief Write a subjectPublicKey to ASN.1 data * Note: function works backwards in data buffer * * \param p reference to current position pointer * \param start start of the buffer (for bounds-checking) * \param key PK context which must contain a valid public or private key. * * \return the length written or a negative error code */ int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start, const mbedtls_pk_context *key ); #endif /* MBEDTLS_PK_WRITE_C */ /* * Internal module functions. You probably do not want to use these unless you * know you do. */ #if defined(MBEDTLS_FS_IO) int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n ); #endif #ifdef __cplusplus } #endif #endif /* MBEDTLS_PK_H */