156083Skris/* crypto/rsa/rsa_sign.c */ 256083Skris/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 356083Skris * All rights reserved. 456083Skris * 556083Skris * This package is an SSL implementation written 656083Skris * by Eric Young (eay@cryptsoft.com). 756083Skris * The implementation was written so as to conform with Netscapes SSL. 8280297Sjkim * 956083Skris * This library is free for commercial and non-commercial use as long as 1056083Skris * the following conditions are aheared to. The following conditions 1156083Skris * apply to all code found in this distribution, be it the RC4, RSA, 1256083Skris * lhash, DES, etc., code; not just the SSL code. The SSL documentation 1356083Skris * included with this distribution is covered by the same copyright terms 1456083Skris * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15280297Sjkim * 1656083Skris * Copyright remains Eric Young's, and as such any Copyright notices in 1756083Skris * the code are not to be removed. 1856083Skris * If this package is used in a product, Eric Young should be given attribution 1956083Skris * as the author of the parts of the library used. 2056083Skris * This can be in the form of a textual message at program startup or 2156083Skris * in documentation (online or textual) provided with the package. 22280297Sjkim * 2356083Skris * Redistribution and use in source and binary forms, with or without 2456083Skris * modification, are permitted provided that the following conditions 2556083Skris * are met: 2656083Skris * 1. Redistributions of source code must retain the copyright 2756083Skris * notice, this list of conditions and the following disclaimer. 2856083Skris * 2. Redistributions in binary form must reproduce the above copyright 2956083Skris * notice, this list of conditions and the following disclaimer in the 3056083Skris * documentation and/or other materials provided with the distribution. 3156083Skris * 3. All advertising materials mentioning features or use of this software 3256083Skris * must display the following acknowledgement: 3356083Skris * "This product includes cryptographic software written by 3456083Skris * Eric Young (eay@cryptsoft.com)" 3556083Skris * The word 'cryptographic' can be left out if the rouines from the library 3656083Skris * being used are not cryptographic related :-). 37280297Sjkim * 4. If you include any Windows specific code (or a derivative thereof) from 3856083Skris * the apps directory (application code) you must include an acknowledgement: 3956083Skris * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40280297Sjkim * 4156083Skris * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 4256083Skris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 4356083Skris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 4456083Skris * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 4556083Skris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 4656083Skris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 4756083Skris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 4856083Skris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 4956083Skris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 5056083Skris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 5156083Skris * SUCH DAMAGE. 52280297Sjkim * 5356083Skris * The licence and distribution terms for any publically available version or 5456083Skris * derivative of this code cannot be changed. i.e. this code cannot simply be 5556083Skris * copied and put under another distribution licence 5656083Skris * [including the GNU Public Licence.] 5756083Skris */ 5856083Skris 5956083Skris#include <stdio.h> 6056083Skris#include "cryptlib.h" 6156083Skris#include <openssl/bn.h> 6256083Skris#include <openssl/rsa.h> 6356083Skris#include <openssl/objects.h> 6456083Skris#include <openssl/x509.h> 65238405Sjkim#include "rsa_locl.h" 6656083Skris 6759191Skris/* Size of an SSL signature: MD5+SHA1 */ 68280297Sjkim#define SSL_SIG_LENGTH 36 6959191Skris 70109998Smarkmint RSA_sign(int type, const unsigned char *m, unsigned int m_len, 71280297Sjkim unsigned char *sigret, unsigned int *siglen, RSA *rsa) 72280297Sjkim{ 73280297Sjkim X509_SIG sig; 74280297Sjkim ASN1_TYPE parameter; 75280297Sjkim int i, j, ret = 1; 76280297Sjkim unsigned char *p, *tmps = NULL; 77280297Sjkim const unsigned char *s = NULL; 78280297Sjkim X509_ALGOR algor; 79280297Sjkim ASN1_OCTET_STRING digest; 80238405Sjkim#ifdef OPENSSL_FIPS 81280297Sjkim if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) 82280297Sjkim && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) { 83280297Sjkim RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD); 84280297Sjkim return 0; 85280297Sjkim } 86238405Sjkim#endif 87337982Sjkim if ((rsa->meth->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) { 88280297Sjkim return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa); 89280297Sjkim } 90280297Sjkim /* Special case: SSL signature, just check the length */ 91280297Sjkim if (type == NID_md5_sha1) { 92280297Sjkim if (m_len != SSL_SIG_LENGTH) { 93280297Sjkim RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH); 94280297Sjkim return (0); 95280297Sjkim } 96280297Sjkim i = SSL_SIG_LENGTH; 97280297Sjkim s = m; 98280297Sjkim } else { 99280297Sjkim sig.algor = &algor; 100280297Sjkim sig.algor->algorithm = OBJ_nid2obj(type); 101280297Sjkim if (sig.algor->algorithm == NULL) { 102280297Sjkim RSAerr(RSA_F_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE); 103280297Sjkim return (0); 104280297Sjkim } 105280297Sjkim if (sig.algor->algorithm->length == 0) { 106280297Sjkim RSAerr(RSA_F_RSA_SIGN, 107280297Sjkim RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); 108280297Sjkim return (0); 109280297Sjkim } 110280297Sjkim parameter.type = V_ASN1_NULL; 111280297Sjkim parameter.value.ptr = NULL; 112280297Sjkim sig.algor->parameter = ¶meter; 11356083Skris 114280297Sjkim sig.digest = &digest; 115280297Sjkim sig.digest->data = (unsigned char *)m; /* TMP UGLY CAST */ 116280297Sjkim sig.digest->length = m_len; 11756083Skris 118280297Sjkim i = i2d_X509_SIG(&sig, NULL); 119280297Sjkim } 120280297Sjkim j = RSA_size(rsa); 121280297Sjkim if (i > (j - RSA_PKCS1_PADDING_SIZE)) { 122280297Sjkim RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); 123280297Sjkim return (0); 124280297Sjkim } 125280297Sjkim if (type != NID_md5_sha1) { 126280297Sjkim tmps = (unsigned char *)OPENSSL_malloc((unsigned int)j + 1); 127280297Sjkim if (tmps == NULL) { 128280297Sjkim RSAerr(RSA_F_RSA_SIGN, ERR_R_MALLOC_FAILURE); 129280297Sjkim return (0); 130280297Sjkim } 131280297Sjkim p = tmps; 132280297Sjkim i2d_X509_SIG(&sig, &p); 133280297Sjkim s = tmps; 134280297Sjkim } 135280297Sjkim i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING); 136280297Sjkim if (i <= 0) 137280297Sjkim ret = 0; 138280297Sjkim else 139280297Sjkim *siglen = i; 14056083Skris 141280297Sjkim if (type != NID_md5_sha1) { 142280297Sjkim OPENSSL_cleanse(tmps, (unsigned int)j + 1); 143280297Sjkim OPENSSL_free(tmps); 144280297Sjkim } 145280297Sjkim return (ret); 146280297Sjkim} 14756083Skris 148273144Sjkim/* 149273144Sjkim * Check DigestInfo structure does not contain extraneous data by reencoding 150280297Sjkim * using DER and checking encoding against original. 151273144Sjkim */ 152280297Sjkimstatic int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo, 153280297Sjkim int dinfolen) 154280297Sjkim{ 155280297Sjkim unsigned char *der = NULL; 156280297Sjkim int derlen; 157280297Sjkim int ret = 0; 158280297Sjkim derlen = i2d_X509_SIG(sig, &der); 159280297Sjkim if (derlen <= 0) 160280297Sjkim return 0; 161280297Sjkim if (derlen == dinfolen && !memcmp(dinfo, der, derlen)) 162280297Sjkim ret = 1; 163280297Sjkim OPENSSL_cleanse(der, derlen); 164280297Sjkim OPENSSL_free(der); 165280297Sjkim return ret; 166280297Sjkim} 167273144Sjkim 168238405Sjkimint int_rsa_verify(int dtype, const unsigned char *m, 169280297Sjkim unsigned int m_len, 170280297Sjkim unsigned char *rm, size_t *prm_len, 171280297Sjkim const unsigned char *sigbuf, size_t siglen, RSA *rsa) 172280297Sjkim{ 173280297Sjkim int i, ret = 0, sigtype; 174280297Sjkim unsigned char *s; 175280297Sjkim X509_SIG *sig = NULL; 17656083Skris 177238405Sjkim#ifdef OPENSSL_FIPS 178280297Sjkim if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) 179280297Sjkim && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) { 180280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD); 181280297Sjkim return 0; 182280297Sjkim } 183238405Sjkim#endif 184238405Sjkim 185280297Sjkim if (siglen != (unsigned int)RSA_size(rsa)) { 186280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH); 187280297Sjkim return (0); 188280297Sjkim } 18956083Skris 190280297Sjkim if ((dtype == NID_md5_sha1) && rm) { 191280297Sjkim i = RSA_public_decrypt((int)siglen, 192280297Sjkim sigbuf, rm, rsa, RSA_PKCS1_PADDING); 193280297Sjkim if (i <= 0) 194280297Sjkim return 0; 195280297Sjkim *prm_len = i; 196280297Sjkim return 1; 197280297Sjkim } 19859191Skris 199280297Sjkim s = (unsigned char *)OPENSSL_malloc((unsigned int)siglen); 200280297Sjkim if (s == NULL) { 201280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE); 202280297Sjkim goto err; 203280297Sjkim } 204280297Sjkim if ((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH)) { 205280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); 206280297Sjkim goto err; 207280297Sjkim } 208280297Sjkim i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING); 209238405Sjkim 210280297Sjkim if (i <= 0) 211280297Sjkim goto err; 212280297Sjkim /* 213280297Sjkim * Oddball MDC2 case: signature can be OCTET STRING. check for correct 214280297Sjkim * tag and length octets. 215280297Sjkim */ 216280297Sjkim if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10) { 217280297Sjkim if (rm) { 218280297Sjkim memcpy(rm, s + 2, 16); 219280297Sjkim *prm_len = 16; 220280297Sjkim ret = 1; 221291719Sjkim } else if (memcmp(m, s + 2, 16)) { 222280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 223291719Sjkim } else { 224280297Sjkim ret = 1; 225291719Sjkim } 226291719Sjkim } else if (dtype == NID_md5_sha1) { 227291719Sjkim /* Special case: SSL signature */ 228280297Sjkim if ((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH)) 229280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 230280297Sjkim else 231280297Sjkim ret = 1; 232280297Sjkim } else { 233280297Sjkim const unsigned char *p = s; 234280297Sjkim sig = d2i_X509_SIG(NULL, &p, (long)i); 23556083Skris 236280297Sjkim if (sig == NULL) 237280297Sjkim goto err; 238162207Ssimon 239280297Sjkim /* Excess data can be used to create forgeries */ 240280297Sjkim if (p != s + i || !rsa_check_digestinfo(sig, s, i)) { 241280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 242280297Sjkim goto err; 243280297Sjkim } 244162207Ssimon 245280297Sjkim /* 246280297Sjkim * Parameters to the signature algorithm can also be used to create 247280297Sjkim * forgeries 248280297Sjkim */ 249280297Sjkim if (sig->algor->parameter 250280297Sjkim && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) { 251280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 252280297Sjkim goto err; 253280297Sjkim } 254162207Ssimon 255280297Sjkim sigtype = OBJ_obj2nid(sig->algor->algorithm); 25656083Skris 257280297Sjkim#ifdef RSA_DEBUG 258280297Sjkim /* put a backward compatibility flag in EAY */ 259280297Sjkim fprintf(stderr, "in(%s) expect(%s)\n", OBJ_nid2ln(sigtype), 260280297Sjkim OBJ_nid2ln(dtype)); 261280297Sjkim#endif 262280297Sjkim if (sigtype != dtype) { 263290207Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_ALGORITHM_MISMATCH); 264290207Sjkim goto err; 265280297Sjkim } 266280297Sjkim if (rm) { 267280297Sjkim const EVP_MD *md; 268280297Sjkim md = EVP_get_digestbynid(dtype); 269280297Sjkim if (md && (EVP_MD_size(md) != sig->digest->length)) 270280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH); 271280297Sjkim else { 272280297Sjkim memcpy(rm, sig->digest->data, sig->digest->length); 273280297Sjkim *prm_len = sig->digest->length; 274280297Sjkim ret = 1; 275280297Sjkim } 276280297Sjkim } else if (((unsigned int)sig->digest->length != m_len) || 277280297Sjkim (memcmp(m, sig->digest->data, m_len) != 0)) { 278280297Sjkim RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 279280297Sjkim } else 280280297Sjkim ret = 1; 281280297Sjkim } 282280297Sjkim err: 283280297Sjkim if (sig != NULL) 284280297Sjkim X509_SIG_free(sig); 285280297Sjkim if (s != NULL) { 286280297Sjkim OPENSSL_cleanse(s, (unsigned int)siglen); 287280297Sjkim OPENSSL_free(s); 288280297Sjkim } 289280297Sjkim return (ret); 290280297Sjkim} 29156083Skris 292238405Sjkimint RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, 293280297Sjkim const unsigned char *sigbuf, unsigned int siglen, RSA *rsa) 294280297Sjkim{ 295238405Sjkim 296337982Sjkim if ((rsa->meth->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) { 297280297Sjkim return rsa->meth->rsa_verify(dtype, m, m_len, sigbuf, siglen, rsa); 298280297Sjkim } 299238405Sjkim 300280297Sjkim return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa); 301280297Sjkim} 302