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摘要：本文主要向大家介绍了C/C++知识点之RSA加密(C语言)，通过具体的内容向大家展示，希望对大家学习C/C++知识点有所帮助。
本文主要向大家介绍了C/C++知识点之RSA加密(C语言)，通过具体的内容向大家展示，希望对大家学习C/C++知识点有所帮助。
/** * \file rsa.h * * \brief The RSA public-key cryptosystem * * Copyright (C) 2006-2010, Brainspark B.V. * * This file is part of PolarSSL (//www.polarssl.org) * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> * * 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"
/* * 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_SHA1_ALT \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x1F" \ ASN1_STR_CONSTRUCTED_SEQUENCE "\x07" \ ASN1_STR_OID "\x05" \ OID_HASH_ALG_SHA1 \ 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 __cplusplusextern "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 */
/* * The RSA public-key cryptosystem * * Copyright (C) 2006-2011, Brainspark B.V. * * This file is part of PolarSSL (//www.polarssl.org) * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> * * 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. *//* * RSA was designed by Ron Rivest, Adi Shamir and Len Adleman. * * //theory.lcs.mit.edu/~rivest/rsapaper.pdf * //www.cacr.math.uwaterloo.ca/hac/about/chap8.pdf */
#include "polarssl/config.h"
#if defined(POLARSSL_RSA_C)
#include "polarssl/rsa.h"#include "polarssl/md.h"
#include <stdlib.h>#include <stdio.h>
/* * Initialize an RSA context */void rsa_init( rsa_context *ctx, int padding, int hash_id ){ memset( ctx, 0, sizeof( rsa_context ) );
ctx->padding = padding; ctx->hash_id = hash_id;}
#if defined(POLARSSL_GENPRIME)
/* * Generate an RSA keypair */int rsa_gen_key( rsa_context *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng, unsigned int nbits, int exponent ){ int ret; mpi P1, Q1, H, G;
if( f_rng == NULL || nbits < 128 || exponent < 3 ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
mpi_init( &P1 ); mpi_init( &Q1 ); mpi_init( &H ); mpi_init( &G );
/* * find primes P and Q with Q < P so that: * GCD( E, (P-1)*(Q-1) ) == 1 */ MPI_CHK( mpi_lset( &ctx->E, exponent ) );
do { MPI_CHK( mpi_gen_prime( &ctx->P, ( nbits + 1 ) >> 1, 0, f_rng, p_rng ) );
MPI_CHK( mpi_gen_prime( &ctx->Q, ( nbits + 1 ) >> 1, 0, f_rng, p_rng ) );
if( mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 ) mpi_swap( &ctx->P, &ctx->Q );
if( mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 ) continue;
MPI_CHK( mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) ); if( mpi_msb( &ctx->N ) != nbits ) continue;
MPI_CHK( mpi_sub_int( &P1, &ctx->P, 1 ) ); MPI_CHK( mpi_sub_int( &Q1, &ctx->Q, 1 ) ); MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) ); MPI_CHK( mpi_gcd( &G, &ctx->E, &H ) ); } while( mpi_cmp_int( &G, 1 ) != 0 );
/* * D = E^-1 mod ((P-1)*(Q-1)) * DP = D mod (P - 1) * DQ = D mod (Q - 1) * QP = Q^-1 mod P */ MPI_CHK( mpi_inv_mod( &ctx->D , &ctx->E, &H ) ); MPI_CHK( mpi_mod_mpi( &ctx->DP, &ctx->D, &P1 ) ); MPI_CHK( mpi_mod_mpi( &ctx->DQ, &ctx->D, &Q1 ) ); MPI_CHK( mpi_inv_mod( &ctx->QP, &ctx->Q, &ctx->P ) );
ctx->len = ( mpi_msb( &ctx->N ) + 7 ) >> 3;
cleanup:
mpi_free( &P1 ); mpi_free( &Q1 ); mpi_free( &H ); mpi_free( &G );
if( ret != 0 ) { rsa_free( ctx ); return( POLARSSL_ERR_RSA_KEY_GEN_FAILED + ret ); }
return( 0 ); }
#endif
/* * Check a public RSA key */int rsa_check_pubkey( const rsa_context *ctx ){ if( !ctx->N.p || !ctx->E.p ) return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
if( ( ctx->N.p[0] & 1 ) == 0 || ( ctx->E.p[0] & 1 ) == 0 ) return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
if( mpi_msb( &ctx->N ) < 128 || mpi_msb( &ctx->N ) > POLARSSL_MPI_MAX_BITS ) return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
if( mpi_msb( &ctx->E ) < 2 || mpi_msb( &ctx->E ) > 64 ) return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
return( 0 );}
/* * Check a private RSA key */int rsa_check_privkey( const rsa_context *ctx ){ int ret; mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2;
if( ( ret = rsa_check_pubkey( ctx ) ) != 0 ) return( ret );
if( !ctx->P.p || !ctx->Q.p || !ctx->D.p ) return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
mpi_init( &PQ ); mpi_init( &DE ); mpi_init( &P1 ); mpi_init( &Q1 ); mpi_init( &H ); mpi_init( &I ); mpi_init( &G ); mpi_init( &G2 ); mpi_init( &L1 ); mpi_init( &L2 );
MPI_CHK( mpi_mul_mpi( &PQ, &ctx->P, &ctx->Q ) ); MPI_CHK( mpi_mul_mpi( &DE, &ctx->D, &ctx->E ) ); MPI_CHK( mpi_sub_int( &P1, &ctx->P, 1 ) ); MPI_CHK( mpi_sub_int( &Q1, &ctx->Q, 1 ) ); MPI_CHK( mpi_mul_mpi( &H, &P1, &Q1 ) ); MPI_CHK( mpi_gcd( &G, &ctx->E, &H ) );
MPI_CHK( mpi_gcd( &G2, &P1, &Q1 ) ); MPI_CHK( mpi_div_mpi( &L1, &L2, &H, &G2 ) ); MPI_CHK( mpi_mod_mpi( &I, &DE, &L1 ) );
/* * Check for a valid PKCS1v2 private key */ if( mpi_cmp_mpi( &PQ, &ctx->N ) != 0 || mpi_cmp_int( &L2, 0 ) != 0 || mpi_cmp_int( &I, 1 ) != 0 || mpi_cmp_int( &G, 1 ) != 0 ) { ret = POLARSSL_ERR_RSA_KEY_CHECK_FAILED; }
cleanup:
mpi_free( &PQ ); mpi_free( &DE ); mpi_free( &P1 ); mpi_free( &Q1 ); mpi_free( &H ); mpi_free( &I ); mpi_free( &G ); mpi_free( &G2 ); mpi_free( &L1 ); mpi_free( &L2 );
if( ret == POLARSSL_ERR_RSA_KEY_CHECK_FAILED ) return( ret );
if( ret != 0 ) return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED + ret );
return( 0 );}
/* * Do an RSA public key operation */int rsa_public( rsa_context *ctx, const unsigned char *input, unsigned char *output ){ int ret; size_t olen; mpi T;
mpi_init( &T );
MPI_CHK( mpi_read_binary( &T, input, ctx->len ) );
if( mpi_cmp_mpi( &T, &ctx->N ) >= 0 ) { mpi_free( &T ); return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); }
olen = ctx->len; MPI_CHK( mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) ); MPI_CHK( mpi_write_binary( &T, output, olen ) );
cleanup:
mpi_free( &T );
if( ret != 0 ) return( POLARSSL_ERR_RSA_PUBLIC_FAILED + ret );
return( 0 );}
/* * Do an RSA private key operation */int rsa_private( rsa_context *ctx, const unsigned char *input, unsigned char *output ){ int ret; size_t olen; mpi T, T1, T2;
mpi_init( &T ); mpi_init( &T1 ); mpi_init( &T2 );
MPI_CHK( mpi_read_binary( &T, input, ctx->len ) );
if( mpi_cmp_mpi( &T, &ctx->N ) >= 0 ) { mpi_free( &T ); return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); }
#if defined(POLARSSL_RSA_NO_CRT) MPI_CHK( mpi_exp_mod( &T, &T, &ctx->D, &ctx->N, &ctx->RN ) );#else /* * faster decryption using the CRT * * T1 = input ^ dP mod P * T2 = input ^ dQ mod Q */ MPI_CHK( mpi_exp_mod( &T1, &T, &ctx->DP, &ctx->P, &ctx->RP ) ); MPI_CHK( mpi_exp_mod( &T2, &T, &ctx->DQ, &ctx->Q, &ctx->RQ ) );
/* * T = (T1 - T2) * (Q^-1 mod P) mod P */ MPI_CHK( mpi_sub_mpi( &T, &T1, &T2 ) ); MPI_CHK( mpi_mul_mpi( &T1, &T, &ctx->QP ) ); MPI_CHK( mpi_mod_mpi( &T, &T1, &ctx->P ) );
/* * output = T2 + T * Q */ MPI_CHK( mpi_mul_mpi( &T1, &T, &ctx->Q ) ); MPI_CHK( mpi_add_mpi( &T, &T2, &T1 ) );#endif
olen = ctx->len; MPI_CHK( mpi_write_binary( &T, output, olen ) );
cleanup:
mpi_free( &T ); mpi_free( &T1 ); mpi_free( &T2 );
if( ret != 0 ) return( POLARSSL_ERR_RSA_PRIVATE_FAILED + ret );
return( 0 );}
#if defined(POLARSSL_PKCS1_V21)/** * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer. * * \param dst buffer to mask * \param dlen length of destination buffer * \param src source of the mask generation * \param slen length of the source buffer * \param md_ctx message digest context to use */static void mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src, size_t slen, md_context_t *md_ctx ){ unsigned char mask[POLARSSL_MD_MAX_SIZE]; unsigned char counter[4]; unsigned char *p; unsigned int hlen; size_t i, use_len;
memset( mask, 0, POLARSSL_MD_MAX_SIZE ); memset( counter, 0, 4 );
hlen = md_ctx->md_info->size;
// Generate and apply dbMask // p = dst;
while( dlen > 0 ) { use_len = hlen; if( dlen < hlen ) use_len = dlen;
md_starts( md_ctx ); md_update( md_ctx, src, slen ); md_update( md_ctx, counter, 4 ); md_finish( md_ctx, mask );
for( i = 0; i < use_len; ++i ) *p++ ^= mask[i];
counter[3]++;
dlen -= use_len; }}#endif
/* * Add the message padding, then do an RSA operation */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 ){ size_t nb_pad, olen; int ret; unsigned char *p = output;#if defined(POLARSSL_PKCS1_V21) unsigned int hlen; const md_info_t *md_info; md_context_t md_ctx;#endif
olen = ctx->len;
if( f_rng == NULL ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
switch( ctx->padding ) { case RSA_PKCS_V15:
if( olen < ilen + 11 ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
nb_pad = olen - 3 - ilen;
*p++ = 0; *p++ = RSA_CRYPT;
while( nb_pad-- > 0 ) { int rng_dl = 100;
do { ret = f_rng( p_rng, p, 1 ); } while( *p == 0 && --rng_dl && ret == 0 );
// Check if RNG failed to generate data // if( rng_dl == 0 || ret != 0) return POLARSSL_ERR_RSA_RNG_FAILED + ret;
p++; } *p++ = 0; memcpy( p, input, ilen ); break; #if defined(POLARSSL_PKCS1_V21) case RSA_PKCS_V21:
md_info = md_info_from_type( ctx->hash_id ); if( md_info == NULL ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
hlen = md_get_size( md_info );
if( olen < ilen + 2 * hlen + 2 || f_rng == NULL ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
memset( output, 0, olen ); memset( &md_ctx, 0, sizeof( md_context_t ) );
md_init_ctx( &md_ctx, md_info );
*p++ = 0;
// Generate a random octet string seed // if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 ) return( POLARSSL_ERR_RSA_RNG_FAILED + ret );
p += hlen;
// Construct DB // md( md_info, p, 0, p ); p += hlen; p += olen - 2 * hlen - 2 - ilen; *p++ = 1; memcpy( p, input, ilen );
// maskedDB: Apply dbMask to DB // mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen, &md_ctx );
// maskedSeed: Apply seedMask to seed // mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1, &md_ctx ); break;#endif
default:
return( POLARSSL_ERR_RSA_INVALID_PADDING ); }
return( ( mode == RSA_PUBLIC ) ? rsa_public( ctx, output, output ) : rsa_private( ctx, output, output ) );}
/* * Do an RSA operation, then remove the message padding */int rsa_pkcs1_decrypt( rsa_context *ctx, int mode, size_t *olen, const unsigned char *input, unsigned char *output, size_t output_max_len){ int ret; size_t ilen; unsigned char *p; unsigned char buf[1024];#if defined(POLARSSL_PKCS1_V21) unsigned char lhash[POLARSSL_MD_MAX_SIZE]; unsigned int hlen; const md_info_t *md_info; md_context_t md_ctx;#endif
ilen = ctx->len;
if( ilen < 16 || ilen > sizeof( buf ) ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
ret = ( mode == RSA_PUBLIC ) ? rsa_public( ctx, input, buf ) : rsa_private( ctx, input, buf );
if( ret != 0 ) return( ret );
p = buf;
switch( ctx->padding ) { case RSA_PKCS_V15:
if( *p++ != 0 || *p++ != RSA_CRYPT ) return( POLARSSL_ERR_RSA_INVALID_PADDING );
while( *p != 0 ) { if( p >= buf + ilen - 1 ) return( POLARSSL_ERR_RSA_INVALID_PADDING ); p++; } p++; break;
#if defined(POLARSSL_PKCS1_V21) case RSA_PKCS_V21: if( *p++ != 0 ) return( POLARSSL_ERR_RSA_INVALID_PADDING );
md_info = md_info_from_type( ctx->hash_id ); if( md_info == NULL ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); hlen = md_get_size( md_info ); memset( &md_ctx, 0, sizeof( md_context_t ) );
md_init_ctx( &md_ctx, md_info ); // Generate lHash // md( md_info, lhash, 0, lhash );
// seed: Apply seedMask to maskedSeed // mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1, &md_ctx );
// DB: Apply dbMask to maskedDB // mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen, &md_ctx );
p += hlen;
// Check validity // if( memcmp( lhash, p, hlen ) != 0 ) return( POLARSSL_ERR_RSA_INVALID_PADDING );
p += hlen;
while( *p == 0 && p < buf + ilen ) p++;
if( p == buf + ilen ) return( POLARSSL_ERR_RSA_INVALID_PADDING );
if( *p++ != 0x01 ) return( POLARSSL_ERR_RSA_INVALID_PADDING );
break;#endif
default:
return( POLARSSL_ERR_RSA_INVALID_PADDING ); }
if (ilen - (p - buf) > output_max_len) return( POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE );
*olen = ilen - (p - buf); memcpy( output, p, *olen );
return( 0 );}
/* * Do an RSA operation to sign the message digest */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 ){ size_t nb_pad, olen; unsigned char *p = sig;#if defined(POLARSSL_PKCS1_V21) unsigned char salt[POLARSSL_MD_MAX_SIZE]; unsigned int slen, hlen, offset = 0; int ret; size_t msb; const md_info_t *md_info; md_context_t md_ctx;#else (void) f_rng; (void) p_rng;#endif
olen = ctx->len;
switch( ctx->padding ) { case RSA_PKCS_V15:
switch( hash_id ) { case SIG_RSA_RAW: nb_pad = olen - 3 - hashlen; break;
case SIG_RSA_MD2: case SIG_RSA_MD4: case SIG_RSA_MD5: nb_pad = olen - 3 - 34; break;
case SIG_RSA_SHA1: nb_pad = olen - 3 - 35; break;
case SIG_RSA_SHA224: nb_pad = olen - 3 - 47; break;
case SIG_RSA_SHA256: nb_pad = olen - 3 - 51; break;
case SIG_RSA_SHA384: nb_pad = olen - 3 - 67; break;
case SIG_RSA_SHA512: nb_pad = olen - 3 - 83; break;
default: return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); }
if( nb_pad < 8 ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
*p++ = 0; *p++ = RSA_SIGN; memset( p, 0xFF, nb_pad ); p += nb_pad; *p++ = 0;
switch( hash_id ) { case SIG_RSA_RAW: memcpy( p, hash, hashlen ); break;
case SIG_RSA_MD2: memcpy( p, ASN1_HASH_MDX, 18 ); memcpy( p + 18, hash, 16 ); p[13] = 2; break;
case SIG_RSA_MD4: memcpy( p, ASN1_HASH_MDX, 18 ); memcpy( p + 18, hash, 16 ); p[13] = 4; break;
case SIG_RSA_MD5: memcpy( p, ASN1_HASH_MDX, 18 ); memcpy( p + 18, hash, 16 ); p[13] = 5; break;
case SIG_RSA_SHA1: memcpy( p, ASN1_HASH_SHA1, 15 ); memcpy( p + 15, hash, 20 ); break;
case SIG_RSA_SHA224: memcpy( p, ASN1_HASH_SHA2X, 19 ); memcpy( p + 19, hash, 28 ); p[1] += 28; p[14] = 4; p[18] += 28; break;
case SIG_RSA_SHA256: memcpy( p, ASN1_HASH_SHA2X, 19 ); memcpy( p + 19, hash, 32 ); p[1] += 32; p[14] = 1; p[18] += 32; break;
case SIG_RSA_SHA384: memcpy( p, ASN1_HASH_SHA2X, 19 ); memcpy( p + 19, hash, 48 ); p[1] += 48; p[14] = 2; p[18] += 48; break;
case SIG_RSA_SHA512: memcpy( p, ASN1_HASH_SHA2X, 19 ); memcpy( p + 19, hash, 64 ); p[1] += 64; p[14] = 3; p[18] += 64; break;
default: return( POLARSSL_ERR_RSA_BAD_INPUT_DATA ); }
break;
#if defined(POLARSSL_PKCS1_V21) case RSA_PKCS_V21:
if( f_rng == NULL ) return( POLARSSL_ERR_RSA_BAD_INPUT_DATA );
switch( hash_id ) { case SIG_RSA_MD2: case SIG_RSA_MD4: case SIG_RSA_MD5: hashlen = 16; break;
case SIG_RSA_SHA1: hashlen = 20; break;
case SIG_RSA_SHA224: hashlen = 28; break;
case SIG_RSA_SHA256: hashlen = 32; break;
case SIG_RSA_SHA384: hashlen = 48; break;
case SIG_RSA_SHA512: hashlen = 64; break;
default: return( POLARSSL_ERR_RS本文由职坐标整理并发布，希望对同学们有所帮助。了解更多详情请关注职坐标编程语言C/C+频道！
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