/** * \file rsa.h * * \brief The RSA public-key cryptosystem * * Copyright (C) 2006-2010, Brainspark B.V. * * This file is part of PolarSSL (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_RSA_H #define POLARSSL_RSA_H #include "bignum.h" #include /* * RSA Error codes */ #define POLARSSL_ERR_RSA_BAD_INPUT_DATA -0x4080 /**< Bad input parameters to function. */ #define POLARSSL_ERR_RSA_INVALID_PADDING -0x4100 /**< Input data contains invalid padding and is rejected. */ #define POLARSSL_ERR_RSA_KEY_GEN_FAILED -0x4180 /**< Something failed during generation of a key. */ #define POLARSSL_ERR_RSA_KEY_CHECK_FAILED -0x4200 /**< Key failed to pass the libraries validity check. */ #define POLARSSL_ERR_RSA_PUBLIC_FAILED -0x4280 /**< The public key operation failed. */ #define POLARSSL_ERR_RSA_PRIVATE_FAILED -0x4300 /**< The private key operation failed. */ #define POLARSSL_ERR_RSA_VERIFY_FAILED -0x4380 /**< The PKCS#1 verification failed. */ #define POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE -0x4400 /**< The output buffer for decryption is not large enough. */ #define POLARSSL_ERR_RSA_RNG_FAILED -0x4480 /**< The random generator failed to generate non-zeros. */ /* * PKCS#1 constants */ #define SIG_RSA_RAW 0 #define SIG_RSA_MD2 2 #define SIG_RSA_MD4 3 #define SIG_RSA_MD5 4 #define SIG_RSA_SHA1 5 #define SIG_RSA_SHA224 14 #define SIG_RSA_SHA256 11 #define SIG_RSA_SHA384 12 #define SIG_RSA_SHA512 13 #define RSA_PUBLIC 0 #define RSA_PRIVATE 1 #define RSA_PKCS_V15 0 #define RSA_PKCS_V21 1 #define RSA_SIGN 1 #define RSA_CRYPT 2 #define ASN1_STR_CONSTRUCTED_SEQUENCE "\x30" #define ASN1_STR_NULL "\x05" #define ASN1_STR_OID "\x06" #define ASN1_STR_OCTET_STRING "\x04" #define OID_DIGEST_ALG_MDX "\x2A\x86\x48\x86\xF7\x0D\x02\x00" #define OID_HASH_ALG_SHA1 "\x2b\x0e\x03\x02\x1a" #define OID_HASH_ALG_SHA2X "\x60\x86\x48\x01\x65\x03\x04\x02\x00" #define OID_ISO_MEMBER_BODIES "\x2a" #define OID_ISO_IDENTIFIED_ORG "\x2b" /* * ISO Member bodies OID parts */ #define OID_COUNTRY_US "\x86\x48" #define OID_RSA_DATA_SECURITY "\x86\xf7\x0d" /* * ISO Identified organization OID parts */ #define OID_OIW_SECSIG_SHA1 "\x0e\x03\x02\x1a" /* * DigestInfo ::= SEQUENCE { * digestAlgorithm DigestAlgorithmIdentifier, * digest Digest } * * DigestAlgorithmIdentifier ::= AlgorithmIdentifier * * Digest ::= OCTET STRING */ #define ASN1_HASH_MDX \ ( \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x20" \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x0C" \ ASN1_STR_OID "\x08" \ OID_DIGEST_ALG_MDX \ ASN1_STR_NULL "\x00" \ ASN1_STR_OCTET_STRING "\x10" \ ) #define ASN1_HASH_SHA1 \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x21" \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x09" \ ASN1_STR_OID "\x05" \ OID_HASH_ALG_SHA1 \ ASN1_STR_NULL "\x00" \ ASN1_STR_OCTET_STRING "\x14" #define ASN1_HASH_SHA2X \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x11" \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x0d" \ ASN1_STR_OID "\x09" \ OID_HASH_ALG_SHA2X \ ASN1_STR_NULL "\x00" \ ASN1_STR_OCTET_STRING "\x00" /** * \brief RSA context structure */ typedef struct { int ver; /*!< always 0 */ size_t len; /*!< size(N) in chars */ mpi N; /*!< public modulus */ mpi E; /*!< public exponent */ mpi D; /*!< private exponent */ mpi P; /*!< 1st prime factor */ mpi Q; /*!< 2nd prime factor */ mpi DP; /*!< D % (P - 1) */ mpi DQ; /*!< D % (Q - 1) */ mpi QP; /*!< 1 / (Q % P) */ mpi RN; /*!< cached R^2 mod N */ mpi RP; /*!< cached R^2 mod P */ mpi RQ; /*!< cached R^2 mod Q */ int padding; /*!< RSA_PKCS_V15 for 1.5 padding and RSA_PKCS_v21 for OAEP/PSS */ int hash_id; /*!< Hash identifier of md_type_t as specified in the md.h header file for the EME-OAEP and EMSA-PSS encoding */ } rsa_context; #ifdef __cplusplus extern "C" { #endif /** * \brief Initialize an RSA context * * \param ctx RSA context to be initialized * \param padding RSA_PKCS_V15 or RSA_PKCS_V21 * \param hash_id RSA_PKCS_V21 hash identifier * * \note The hash_id parameter is actually ignored * when using RSA_PKCS_V15 padding. */ void rsa_init( rsa_context *ctx, int padding, int hash_id); /** * \brief Generate an RSA keypair * * \param ctx RSA context that will hold the key * \param f_rng RNG function * \param p_rng RNG parameter * \param nbits size of the public key in bits * \param exponent public exponent (e.g., 65537) * * \note rsa_init() must be called beforehand to setup * the RSA context. * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code */ int rsa_gen_key( rsa_context *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, unsigned int nbits, int exponent ); /** * \brief Check a public RSA key * * \param ctx RSA context to be checked * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code */ int rsa_check_pubkey( const rsa_context *ctx ); /** * \brief Check a private RSA key * * \param ctx RSA context to be checked * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code */ int rsa_check_privkey( const rsa_context *ctx ); /** * \brief Do an RSA public key operation * * \param ctx RSA context * \param input input buffer * \param output output buffer * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code * * \note This function does NOT take care of message * padding. Also, be sure to set input[0] = 0 or assure that * input is smaller than N. * * \note The input and output buffers must be large * enough (eg. 128 bytes if RSA-1024 is used). */ int rsa_public( rsa_context *ctx, const unsigned char *input, unsigned char *output ); /** * \brief Do an RSA private key operation * * \param ctx RSA context * \param input input buffer * \param output output buffer * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code * * \note The input and output buffers must be large * enough (eg. 128 bytes if RSA-1024 is used). */ int rsa_private( rsa_context *ctx, const unsigned char *input, unsigned char *output ); /** * \brief Add the message padding, then do an RSA operation * * \param ctx RSA context * \param f_rng RNG function (Needed for padding and PKCS#1 v2.1 encoding) * \param p_rng RNG parameter * \param mode RSA_PUBLIC or RSA_PRIVATE * \param ilen contains the plaintext length * \param input buffer holding the data to be encrypted * \param output buffer that will hold the ciphertext * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code * * \note The output buffer must be as large as the size * of ctx->N (eg. 128 bytes if RSA-1024 is used). */ int rsa_pkcs1_encrypt( rsa_context *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, size_t ilen, const unsigned char *input, unsigned char *output ); /** * \brief Do an RSA operation, then remove the message padding * * \param ctx RSA context * \param mode RSA_PUBLIC or RSA_PRIVATE * \param olen will contain the plaintext length * \param input buffer holding the encrypted data * \param output buffer that will hold the plaintext * \param output_max_len maximum length of the output buffer * * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code * * \note The output buffer must be as large as the size * of ctx->N (eg. 128 bytes if RSA-1024 is used) otherwise * an error is thrown. */ int rsa_pkcs1_decrypt( rsa_context *ctx, int mode, size_t *olen, const unsigned char *input, unsigned char *output, size_t output_max_len ); /** * \brief Do a private RSA to sign a message digest * * \param ctx RSA context * \param f_rng RNG function (Needed for PKCS#1 v2.1 encoding) * \param p_rng RNG parameter * \param mode RSA_PUBLIC or RSA_PRIVATE * \param hash_id SIG_RSA_RAW, SIG_RSA_MD{2,4,5} or SIG_RSA_SHA{1,224,256,384,512} * \param hashlen message digest length (for SIG_RSA_RAW only) * \param hash buffer holding the message digest * \param sig buffer that will hold the ciphertext * * \return 0 if the signing operation was successful, * or an POLARSSL_ERR_RSA_XXX error code * * \note The "sig" buffer must be as large as the size * of ctx->N (eg. 128 bytes if RSA-1024 is used). * * \note In case of PKCS#1 v2.1 encoding keep in mind that * the hash_id in the RSA context is the one used for the * encoding. hash_id in the function call is the type of hash * that is encoded. According to RFC 3447 it is advised to * keep both hashes the same. */ int rsa_pkcs1_sign( rsa_context *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, int hash_id, unsigned int hashlen, const unsigned char *hash, unsigned char *sig ); /** * \brief Do a public RSA and check the message digest * * \param ctx points to an RSA public key * \param mode RSA_PUBLIC or RSA_PRIVATE * \param hash_id SIG_RSA_RAW, SIG_RSA_MD{2,4,5} or SIG_RSA_SHA{1,224,256,384,512} * \param hashlen message digest length (for SIG_RSA_RAW only) * \param hash buffer holding the message digest * \param sig buffer holding the ciphertext * * \return 0 if the verify operation was successful, * or an POLARSSL_ERR_RSA_XXX error code * * \note The "sig" buffer must be as large as the size * of ctx->N (eg. 128 bytes if RSA-1024 is used). * * \note In case of PKCS#1 v2.1 encoding keep in mind that * the hash_id in the RSA context is the one used for the * verification. hash_id in the function call is the type of hash * that is verified. According to RFC 3447 it is advised to * keep both hashes the same. */ int rsa_pkcs1_verify( rsa_context *ctx, int mode, int hash_id, unsigned int hashlen, const unsigned char *hash, unsigned char *sig ); /** * \brief Free the components of an RSA key * * \param ctx RSA Context to free */ void rsa_free( rsa_context *ctx ); /** * \brief Checkup routine * * \return 0 if successful, or 1 if the test failed */ int rsa_self_test( int verbose ); #ifdef __cplusplus } #endif #endif /* rsa.h */