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. 8296341Sdelphij * 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). 15296341Sdelphij * 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. 22296341Sdelphij * 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 :-). 37296341Sdelphij * 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)" 40296341Sdelphij * 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. 52296341Sdelphij * 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 */ 68296341Sdelphij#define SSL_SIG_LENGTH 36 6959191Skris 70109998Smarkmint RSA_sign(int type, const unsigned char *m, unsigned int m_len, 71296341Sdelphij unsigned char *sigret, unsigned int *siglen, RSA *rsa) 72296341Sdelphij{ 73296341Sdelphij X509_SIG sig; 74296341Sdelphij ASN1_TYPE parameter; 75296341Sdelphij int i, j, ret = 1; 76296341Sdelphij unsigned char *p, *tmps = NULL; 77296341Sdelphij const unsigned char *s = NULL; 78296341Sdelphij X509_ALGOR algor; 79296341Sdelphij ASN1_OCTET_STRING digest; 80238405Sjkim#ifdef OPENSSL_FIPS 81296341Sdelphij if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) 82296341Sdelphij && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) { 83296341Sdelphij RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD); 84296341Sdelphij return 0; 85296341Sdelphij } 86238405Sjkim#endif 87296341Sdelphij if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) { 88296341Sdelphij return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa); 89296341Sdelphij } 90296341Sdelphij /* Special case: SSL signature, just check the length */ 91296341Sdelphij if (type == NID_md5_sha1) { 92296341Sdelphij if (m_len != SSL_SIG_LENGTH) { 93296341Sdelphij RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH); 94296341Sdelphij return (0); 95296341Sdelphij } 96296341Sdelphij i = SSL_SIG_LENGTH; 97296341Sdelphij s = m; 98296341Sdelphij } else { 99296341Sdelphij sig.algor = &algor; 100296341Sdelphij sig.algor->algorithm = OBJ_nid2obj(type); 101296341Sdelphij if (sig.algor->algorithm == NULL) { 102296341Sdelphij RSAerr(RSA_F_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE); 103296341Sdelphij return (0); 104296341Sdelphij } 105296341Sdelphij if (sig.algor->algorithm->length == 0) { 106296341Sdelphij RSAerr(RSA_F_RSA_SIGN, 107296341Sdelphij RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); 108296341Sdelphij return (0); 109296341Sdelphij } 110296341Sdelphij parameter.type = V_ASN1_NULL; 111296341Sdelphij parameter.value.ptr = NULL; 112296341Sdelphij sig.algor->parameter = ¶meter; 11356083Skris 114296341Sdelphij sig.digest = &digest; 115296341Sdelphij sig.digest->data = (unsigned char *)m; /* TMP UGLY CAST */ 116296341Sdelphij sig.digest->length = m_len; 11756083Skris 118296341Sdelphij i = i2d_X509_SIG(&sig, NULL); 119296341Sdelphij } 120296341Sdelphij j = RSA_size(rsa); 121296341Sdelphij if (i > (j - RSA_PKCS1_PADDING_SIZE)) { 122296341Sdelphij RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); 123296341Sdelphij return (0); 124296341Sdelphij } 125296341Sdelphij if (type != NID_md5_sha1) { 126296341Sdelphij tmps = (unsigned char *)OPENSSL_malloc((unsigned int)j + 1); 127296341Sdelphij if (tmps == NULL) { 128296341Sdelphij RSAerr(RSA_F_RSA_SIGN, ERR_R_MALLOC_FAILURE); 129296341Sdelphij return (0); 130296341Sdelphij } 131296341Sdelphij p = tmps; 132296341Sdelphij i2d_X509_SIG(&sig, &p); 133296341Sdelphij s = tmps; 134296341Sdelphij } 135296341Sdelphij i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING); 136296341Sdelphij if (i <= 0) 137296341Sdelphij ret = 0; 138296341Sdelphij else 139296341Sdelphij *siglen = i; 14056083Skris 141296341Sdelphij if (type != NID_md5_sha1) { 142296341Sdelphij OPENSSL_cleanse(tmps, (unsigned int)j + 1); 143296341Sdelphij OPENSSL_free(tmps); 144296341Sdelphij } 145296341Sdelphij return (ret); 146296341Sdelphij} 14756083Skris 148273399Sdelphij/* 149273399Sdelphij * Check DigestInfo structure does not contain extraneous data by reencoding 150296341Sdelphij * using DER and checking encoding against original. 151273399Sdelphij */ 152296341Sdelphijstatic int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo, 153296341Sdelphij int dinfolen) 154296341Sdelphij{ 155296341Sdelphij unsigned char *der = NULL; 156296341Sdelphij int derlen; 157296341Sdelphij int ret = 0; 158296341Sdelphij derlen = i2d_X509_SIG(sig, &der); 159296341Sdelphij if (derlen <= 0) 160296341Sdelphij return 0; 161296341Sdelphij if (derlen == dinfolen && !memcmp(dinfo, der, derlen)) 162296341Sdelphij ret = 1; 163296341Sdelphij OPENSSL_cleanse(der, derlen); 164296341Sdelphij OPENSSL_free(der); 165296341Sdelphij return ret; 166296341Sdelphij} 167273399Sdelphij 168238405Sjkimint int_rsa_verify(int dtype, const unsigned char *m, 169296341Sdelphij unsigned int m_len, 170296341Sdelphij unsigned char *rm, size_t *prm_len, 171296341Sdelphij const unsigned char *sigbuf, size_t siglen, RSA *rsa) 172296341Sdelphij{ 173296341Sdelphij int i, ret = 0, sigtype; 174296341Sdelphij unsigned char *s; 175296341Sdelphij X509_SIG *sig = NULL; 17656083Skris 177238405Sjkim#ifdef OPENSSL_FIPS 178296341Sdelphij if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) 179296341Sdelphij && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) { 180296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD); 181296341Sdelphij return 0; 182296341Sdelphij } 183238405Sjkim#endif 184238405Sjkim 185296341Sdelphij if (siglen != (unsigned int)RSA_size(rsa)) { 186296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH); 187296341Sdelphij return (0); 188296341Sdelphij } 18956083Skris 190296341Sdelphij if ((dtype == NID_md5_sha1) && rm) { 191296341Sdelphij i = RSA_public_decrypt((int)siglen, 192296341Sdelphij sigbuf, rm, rsa, RSA_PKCS1_PADDING); 193296341Sdelphij if (i <= 0) 194296341Sdelphij return 0; 195296341Sdelphij *prm_len = i; 196296341Sdelphij return 1; 197296341Sdelphij } 19859191Skris 199296341Sdelphij s = (unsigned char *)OPENSSL_malloc((unsigned int)siglen); 200296341Sdelphij if (s == NULL) { 201296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE); 202296341Sdelphij goto err; 203296341Sdelphij } 204296341Sdelphij if ((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH)) { 205296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH); 206296341Sdelphij goto err; 207296341Sdelphij } 208296341Sdelphij i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING); 209238405Sjkim 210296341Sdelphij if (i <= 0) 211296341Sdelphij goto err; 212296341Sdelphij /* 213296341Sdelphij * Oddball MDC2 case: signature can be OCTET STRING. check for correct 214296341Sdelphij * tag and length octets. 215296341Sdelphij */ 216296341Sdelphij if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10) { 217296341Sdelphij if (rm) { 218296341Sdelphij memcpy(rm, s + 2, 16); 219296341Sdelphij *prm_len = 16; 220296341Sdelphij ret = 1; 221296341Sdelphij } else if (memcmp(m, s + 2, 16)) 222296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 223296341Sdelphij else 224296341Sdelphij ret = 1; 225296341Sdelphij } 22656083Skris 227296341Sdelphij /* Special case: SSL signature */ 228296341Sdelphij if (dtype == NID_md5_sha1) { 229296341Sdelphij if ((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH)) 230296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 231296341Sdelphij else 232296341Sdelphij ret = 1; 233296341Sdelphij } else { 234296341Sdelphij const unsigned char *p = s; 235296341Sdelphij sig = d2i_X509_SIG(NULL, &p, (long)i); 23656083Skris 237296341Sdelphij if (sig == NULL) 238296341Sdelphij goto err; 239162207Ssimon 240296341Sdelphij /* Excess data can be used to create forgeries */ 241296341Sdelphij if (p != s + i || !rsa_check_digestinfo(sig, s, i)) { 242296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 243296341Sdelphij goto err; 244296341Sdelphij } 245162207Ssimon 246296341Sdelphij /* 247296341Sdelphij * Parameters to the signature algorithm can also be used to create 248296341Sdelphij * forgeries 249296341Sdelphij */ 250296341Sdelphij if (sig->algor->parameter 251296341Sdelphij && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) { 252296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 253296341Sdelphij goto err; 254296341Sdelphij } 255162207Ssimon 256296341Sdelphij sigtype = OBJ_obj2nid(sig->algor->algorithm); 25756083Skris 258296341Sdelphij#ifdef RSA_DEBUG 259296341Sdelphij /* put a backward compatibility flag in EAY */ 260296341Sdelphij fprintf(stderr, "in(%s) expect(%s)\n", OBJ_nid2ln(sigtype), 261296341Sdelphij OBJ_nid2ln(dtype)); 262296341Sdelphij#endif 263296341Sdelphij if (sigtype != dtype) { 264296341Sdelphij if (((dtype == NID_md5) && 265296341Sdelphij (sigtype == NID_md5WithRSAEncryption)) || 266296341Sdelphij ((dtype == NID_md2) && 267296341Sdelphij (sigtype == NID_md2WithRSAEncryption))) { 268296341Sdelphij /* ok, we will let it through */ 269109998Smarkm#if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16) 270296341Sdelphij fprintf(stderr, 271296341Sdelphij "signature has problems, re-make with post SSLeay045\n"); 272109998Smarkm#endif 273296341Sdelphij } else { 274296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_ALGORITHM_MISMATCH); 275296341Sdelphij goto err; 276296341Sdelphij } 277296341Sdelphij } 278296341Sdelphij if (rm) { 279296341Sdelphij const EVP_MD *md; 280296341Sdelphij md = EVP_get_digestbynid(dtype); 281296341Sdelphij if (md && (EVP_MD_size(md) != sig->digest->length)) 282296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH); 283296341Sdelphij else { 284296341Sdelphij memcpy(rm, sig->digest->data, sig->digest->length); 285296341Sdelphij *prm_len = sig->digest->length; 286296341Sdelphij ret = 1; 287296341Sdelphij } 288296341Sdelphij } else if (((unsigned int)sig->digest->length != m_len) || 289296341Sdelphij (memcmp(m, sig->digest->data, m_len) != 0)) { 290296341Sdelphij RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE); 291296341Sdelphij } else 292296341Sdelphij ret = 1; 293296341Sdelphij } 294296341Sdelphij err: 295296341Sdelphij if (sig != NULL) 296296341Sdelphij X509_SIG_free(sig); 297296341Sdelphij if (s != NULL) { 298296341Sdelphij OPENSSL_cleanse(s, (unsigned int)siglen); 299296341Sdelphij OPENSSL_free(s); 300296341Sdelphij } 301296341Sdelphij return (ret); 302296341Sdelphij} 30356083Skris 304238405Sjkimint RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, 305296341Sdelphij const unsigned char *sigbuf, unsigned int siglen, RSA *rsa) 306296341Sdelphij{ 307238405Sjkim 308296341Sdelphij if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) { 309296341Sdelphij return rsa->meth->rsa_verify(dtype, m, m_len, sigbuf, siglen, rsa); 310296341Sdelphij } 311238405Sjkim 312296341Sdelphij return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa); 313296341Sdelphij} 314