/** * \file pk.h * * \brief Public Key abstraction layer * * Copyright (C) 2006-2013, ARM Limited, All Rights Reserved * * This file is part of mbed TLS (http://www.polarssl.org) * Lead Maintainer: Paul Bakker * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef POLARSSL_PK_H #define POLARSSL_PK_H #if !defined(POLARSSL_CONFIG_FILE) #include "config.h" #else #include POLARSSL_CONFIG_FILE #endif #include "md.h" #if defined(POLARSSL_RSA_C) #include "rsa.h" #endif #if defined(POLARSSL_ECP_C) #include "ecp.h" #endif #if defined(POLARSSL_ECDSA_C) #include "ecdsa.h" #endif #define POLARSSL_ERR_PK_MALLOC_FAILED -0x2F80 /**< Memory alloation failed. */ #define POLARSSL_ERR_PK_TYPE_MISMATCH -0x2F00 /**< Type mismatch, eg attempt to encrypt with an ECDSA key */ #define POLARSSL_ERR_PK_BAD_INPUT_DATA -0x2E80 /**< Bad input parameters to function. */ #define POLARSSL_ERR_PK_FILE_IO_ERROR -0x2E00 /**< Read/write of file failed. */ #define POLARSSL_ERR_PK_KEY_INVALID_VERSION -0x2D80 /**< Unsupported key version */ #define POLARSSL_ERR_PK_KEY_INVALID_FORMAT -0x2D00 /**< Invalid key tag or value. */ #define POLARSSL_ERR_PK_UNKNOWN_PK_ALG -0x2C80 /**< Key algorithm is unsupported (only RSA and EC are supported). */ #define POLARSSL_ERR_PK_PASSWORD_REQUIRED -0x2C00 /**< Private key password can't be empty. */ #define POLARSSL_ERR_PK_PASSWORD_MISMATCH -0x2B80 /**< Given private key password does not allow for correct decryption. */ #define POLARSSL_ERR_PK_INVALID_PUBKEY -0x2B00 /**< The pubkey tag or value is invalid (only RSA and EC are supported). */ #define POLARSSL_ERR_PK_INVALID_ALG -0x2A80 /**< The algorithm tag or value is invalid. */ #define POLARSSL_ERR_PK_UNKNOWN_NAMED_CURVE -0x2A00 /**< Elliptic curve is unsupported (only NIST curves are supported). */ #define POLARSSL_ERR_PK_FEATURE_UNAVAILABLE -0x2980 /**< Unavailable feature, e.g. RSA disabled for RSA key. */ #define POLARSSL_ERR_PK_SIG_LEN_MISMATCH -0x2000 /**< The signature is valid but its length is less than expected. */ #if defined(POLARSSL_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 macro! */ #define pk_rsa( pk ) ( (rsa_context *) (pk).pk_ctx ) #endif /* POLARSSL_RSA_C */ #if defined(POLARSSL_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 macro! */ #define pk_ec( pk ) ( (ecp_keypair *) (pk).pk_ctx ) #endif /* POLARSSL_ECP_C */ #ifdef __cplusplus extern "C" { #endif /** * \brief Public key types */ typedef enum { POLARSSL_PK_NONE=0, POLARSSL_PK_RSA, POLARSSL_PK_ECKEY, POLARSSL_PK_ECKEY_DH, POLARSSL_PK_ECDSA, POLARSSL_PK_RSA_ALT, POLARSSL_PK_RSASSA_PSS, } pk_type_t; /** * \brief Options for RSASSA-PSS signature verification. * See \c rsa_rsassa_pss_verify_ext() */ typedef struct { md_type_t mgf1_hash_id; int expected_salt_len; } pk_rsassa_pss_options; /** * \brief Types for interfacing with the debug module */ typedef enum { POLARSSL_PK_DEBUG_NONE = 0, POLARSSL_PK_DEBUG_MPI, POLARSSL_PK_DEBUG_ECP, } pk_debug_type; /** * \brief Item to send to the debug module */ typedef struct { pk_debug_type type; const char *name; void *value; } pk_debug_item; /** Maximum number of item send for debugging, plus 1 */ #define POLARSSL_PK_DEBUG_MAX_ITEMS 3 /** * \brief Public key information and operations */ typedef struct { /** Public key type */ pk_type_t type; /** Type name */ const char *name; /** Get key size in bits */ size_t (*get_size)( const void * ); /** Tell if the context implements this type (e.g. ECKEY can do ECDSA) */ int (*can_do)( pk_type_t type ); /** Verify signature */ int (*verify_func)( void *ctx, md_type_t md_alg, const unsigned char *hash, size_t hash_len, const unsigned char *sig, size_t sig_len ); /** Make signature */ int (*sign_func)( void *ctx, 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 ); /** Decrypt message */ int (*decrypt_func)( void *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 ); /** Encrypt message */ int (*encrypt_func)( void *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 ); /** Check public-private key pair */ int (*check_pair_func)( const void *pub, const void *prv ); /** Allocate a new context */ void * (*ctx_alloc_func)( void ); /** Free the given context */ void (*ctx_free_func)( void *ctx ); /** Interface with the debug module */ void (*debug_func)( const void *ctx, pk_debug_item *items ); } pk_info_t; /** * \brief Public key container */ typedef struct { const pk_info_t * pk_info; /**< Public key informations */ void * pk_ctx; /**< Underlying public key context */ } pk_context; /** * \brief Types for RSA-alt abstraction */ typedef int (*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 (*pk_rsa_alt_sign_func)( void *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, unsigned char *sig ); typedef size_t (*pk_rsa_alt_key_len_func)( void *ctx ); /** * \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 pk_info_t *pk_info_from_type( pk_type_t pk_type ); /** * \brief Initialize a pk_context (as NONE) */ void pk_init( pk_context *ctx ); /** * \brief Free a pk_context */ void pk_free( pk_context *ctx ); /** * \brief Initialize a PK context with the information given * and allocates the type-specific PK subcontext. * * \param ctx Context to initialize. Must be empty (type NONE). * \param info Information to use * * \return 0 on success, * POLARSSL_ERR_PK_BAD_INPUT_DATA on invalid input, * POLARSSL_ERR_PK_MALLOC_FAILED on allocation failure. * * \note For contexts holding an RSA-alt key, use * \c pk_init_ctx_rsa_alt() instead. */ int pk_init_ctx( pk_context *ctx, const pk_info_t *info ); /** * \brief Initialize an RSA-alt context * * \param ctx Context to initialize. Must be empty (type 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 POLARSSL_ERR_PK_BAD_INPUT_DATA if the * context wasn't already initialized as RSA_ALT. * * \note This function replaces \c pk_init_ctx() for RSA-alt. */ int pk_init_ctx_rsa_alt( pk_context *ctx, void * key, pk_rsa_alt_decrypt_func decrypt_func, pk_rsa_alt_sign_func sign_func, pk_rsa_alt_key_len_func key_len_func ); /** * \brief Get the size in bits of the underlying key * * \param ctx Context to use * * \return Key size in bits, or 0 on error */ size_t pk_get_size( const pk_context *ctx ); /** * \brief Get the length in bytes of the underlying key * \param ctx Context to use * * \return Key length in bytes, or 0 on error */ static inline size_t pk_get_len( const pk_context *ctx ) { return( ( pk_get_size( ctx ) + 7 ) / 8 ); } /** * \brief Tell if a context can do the operation given by type * * \param ctx Context to test * \param type Target type * * \return 0 if context can't do the operations, * 1 otherwise. */ int pk_can_do( pk_context *ctx, pk_type_t type ); /** * \brief Verify signature (including padding if relevant). * * \param ctx PK context to use * \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), * POLARSSL_ERR_PK_SIG_LEN_MISMATCH if the signature is * valid but its actual length is less than sig_len, * or a specific error code. * * \note For RSA keys, the default padding type is PKCS#1 v1.5. * Use \c pk_verify_ext( POLARSSL_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 POLARSSL_MD_NONE, only if hash_len != 0 */ int pk_verify( pk_context *ctx, md_type_t md_alg, const unsigned char *hash, size_t hash_len, const unsigned char *sig, size_t sig_len ); /** * \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 PK context to use * \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), * POLARSSL_ERR_PK_TYPE_MISMATCH if the PK context can't be * used for this type of signatures, * POLARSSL_ERR_PK_SIG_LEN_MISMATCH if the signature is * valid but its actual length is less than sig_len, * 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 POLARSSL_MD_NONE, only if hash_len != 0 * * \note If type is POLARSSL_PK_RSASSA_PSS, then options must point * to a pk_rsassa_pss_options structure, * otherwise it must be NULL. */ int pk_verify_ext( pk_type_t type, const void *options, pk_context *ctx, 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 PK context to use * \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 md_alg may be POLARSSL_MD_NONE, only if hash_len != 0 */ int pk_sign( pk_context *ctx, 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 Decrypt message (including padding if relevant). * * \param ctx PK context to use * \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 pk_decrypt( 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 PK context to use * \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 pk_encrypt( 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 POLARSSL_ERR_PK_BAD_INPUT_DATA */ int pk_check_pair( const pk_context *pub, const pk_context *prv ); /** * \brief Export debug information * * \param ctx Context to use * \param items Place to write debug items * * \return 0 on success or POLARSSL_ERR_PK_BAD_INPUT_DATA */ int pk_debug( const pk_context *ctx, pk_debug_item *items ); /** * \brief Access the type name * * \param ctx Context to use * * \return Type name on success, or "invalid PK" */ const char * pk_get_name( const pk_context *ctx ); /** * \brief Get the key type * * \param ctx Context to use * * \return Type on success, or POLARSSL_PK_NONE */ pk_type_t pk_get_type( const pk_context *ctx ); #if defined(POLARSSL_PK_PARSE_C) /** \ingroup pk_module */ /** * \brief Parse a private key * * \param ctx key to be initialized * \param key input buffer * \param keylen size of the buffer * \param pwd password for decryption (optional) * \param pwdlen size of the password * * \note On entry, ctx must be empty, either freshly initialised * with pk_init() or reset with pk_free(). If you need a * specific key type, check the result with pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int pk_parse_key( 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 * * \param ctx key to be initialized * \param key input buffer * \param keylen size of the buffer * * \note On entry, ctx must be empty, either freshly initialised * with pk_init() or reset with pk_free(). If you need a * specific key type, check the result with pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int pk_parse_public_key( pk_context *ctx, const unsigned char *key, size_t keylen ); #if defined(POLARSSL_FS_IO) /** \ingroup pk_module */ /** * \brief Load and parse a private key * * \param ctx key to be initialized * \param path filename to read the private key from * \param password password to decrypt the file (can be NULL) * * \note On entry, ctx must be empty, either freshly initialised * with pk_init() or reset with pk_free(). If you need a * specific key type, check the result with pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int pk_parse_keyfile( pk_context *ctx, const char *path, const char *password ); /** \ingroup pk_module */ /** * \brief Load and parse a public key * * \param ctx key to be initialized * \param path filename to read the private key from * * \note On entry, ctx must be empty, either freshly initialised * with pk_init() or reset with pk_free(). If you need a * specific key type, check the result with pk_can_do(). * * \note The key is also checked for correctness. * * \return 0 if successful, or a specific PK or PEM error code */ int pk_parse_public_keyfile( pk_context *ctx, const char *path ); #endif /* POLARSSL_FS_IO */ #endif /* POLARSSL_PK_PARSE_C */ #if defined(POLARSSL_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 private to write away * \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 pk_write_key_der( 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 public key to write away * \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 pk_write_pubkey_der( pk_context *ctx, unsigned char *buf, size_t size ); #if defined(POLARSSL_PEM_WRITE_C) /** * \brief Write a public key to a PEM string * * \param ctx public key to write away * \param buf buffer to write to * \param size size of the buffer * * \return 0 successful, or a specific error code */ int pk_write_pubkey_pem( pk_context *ctx, unsigned char *buf, size_t size ); /** * \brief Write a private key to a PKCS#1 or SEC1 PEM string * * \param ctx private to write away * \param buf buffer to write to * \param size size of the buffer * * \return 0 successful, or a specific error code */ int pk_write_key_pem( pk_context *ctx, unsigned char *buf, size_t size ); #endif /* POLARSSL_PEM_WRITE_C */ #endif /* POLARSSL_PK_WRITE_C */ /* * WARNING: Low-level functions. You probably do not want to use these unless * you are certain you do ;) */ #if defined(POLARSSL_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 key to fill * * \return 0 if successful, or a specific PK error code */ int pk_parse_subpubkey( unsigned char **p, const unsigned char *end, pk_context *pk ); #endif /* POLARSSL_PK_PARSE_C */ #if defined(POLARSSL_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 public key to write away * * \return the length written or a negative error code */ int pk_write_pubkey( unsigned char **p, unsigned char *start, const pk_context *key ); #endif /* POLARSSL_PK_WRITE_C */ /* * Internal module functions. You probably do not want to use these unless you * know you do. */ #if defined(POLARSSL_FS_IO) int pk_load_file( const char *path, unsigned char **buf, size_t *n ); #endif #ifdef __cplusplus } #endif #endif /* POLARSSL_PK_H */