rsa_sign.c revision 279265
1/* crypto/rsa/rsa_sign.c */ 2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59#include <stdio.h> 60#include "cryptlib.h" 61#include <openssl/bn.h> 62#include <openssl/rsa.h> 63#include <openssl/objects.h> 64#include <openssl/x509.h> 65 66/* Size of an SSL signature: MD5+SHA1 */ 67#define SSL_SIG_LENGTH 36 68 69int RSA_sign(int type, const unsigned char *m, unsigned int m_len, 70 unsigned char *sigret, unsigned int *siglen, RSA *rsa) 71 { 72 X509_SIG sig; 73 ASN1_TYPE parameter; 74 int i,j,ret=1; 75 unsigned char *p, *tmps = NULL; 76 const unsigned char *s = NULL; 77 X509_ALGOR algor; 78 ASN1_OCTET_STRING digest; 79 if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) 80 { 81 return rsa->meth->rsa_sign(type, m, m_len, 82 sigret, siglen, rsa); 83 } 84 /* Special case: SSL signature, just check the length */ 85 if(type == NID_md5_sha1) { 86 if(m_len != SSL_SIG_LENGTH) { 87 RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH); 88 return(0); 89 } 90 i = SSL_SIG_LENGTH; 91 s = m; 92 } else { 93 /* NB: in FIPS mode block anything that isn't a TLS signature */ 94#ifdef OPENSSL_FIPS 95 if(FIPS_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) 96 { 97 RSAerr(RSA_F_RSA_SIGN, RSA_R_OPERATION_NOT_ALLOWED_IN_FIPS_MODE); 98 return 0; 99 } 100#endif 101 sig.algor= &algor; 102 sig.algor->algorithm=OBJ_nid2obj(type); 103 if (sig.algor->algorithm == NULL) 104 { 105 RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE); 106 return(0); 107 } 108 if (sig.algor->algorithm->length == 0) 109 { 110 RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); 111 return(0); 112 } 113 parameter.type=V_ASN1_NULL; 114 parameter.value.ptr=NULL; 115 sig.algor->parameter= ¶meter; 116 117 sig.digest= &digest; 118 sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */ 119 sig.digest->length=m_len; 120 121 i=i2d_X509_SIG(&sig,NULL); 122 } 123 j=RSA_size(rsa); 124 if (i > (j-RSA_PKCS1_PADDING_SIZE)) 125 { 126 RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); 127 return(0); 128 } 129 if(type != NID_md5_sha1) { 130 tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1); 131 if (tmps == NULL) 132 { 133 RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE); 134 return(0); 135 } 136 p=tmps; 137 i2d_X509_SIG(&sig,&p); 138 s=tmps; 139 } 140#ifdef OPENSSL_FIPS 141 /* Bypass algorithm blocking: this is allowed if we get this far */ 142 i=rsa->meth->rsa_priv_enc(i,s,sigret,rsa,RSA_PKCS1_PADDING); 143#else 144 i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING); 145#endif 146 if (i <= 0) 147 ret=0; 148 else 149 *siglen=i; 150 151 if(type != NID_md5_sha1) { 152 OPENSSL_cleanse(tmps,(unsigned int)j+1); 153 OPENSSL_free(tmps); 154 } 155 return(ret); 156 } 157 158/* 159 * Check DigestInfo structure does not contain extraneous data by reencoding 160 * using DER and checking encoding against original. 161 */ 162static int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo, int dinfolen) 163 { 164 unsigned char *der = NULL; 165 int derlen; 166 int ret = 0; 167 derlen = i2d_X509_SIG(sig, &der); 168 if (derlen <= 0) 169 return 0; 170 if (derlen == dinfolen && !memcmp(dinfo, der, derlen)) 171 ret = 1; 172 OPENSSL_cleanse(der, derlen); 173 OPENSSL_free(der); 174 return ret; 175 } 176 177int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, 178 unsigned char *sigbuf, unsigned int siglen, RSA *rsa) 179 { 180 int i,ret=0,sigtype; 181 unsigned char *s; 182 X509_SIG *sig=NULL; 183 184 if (siglen != (unsigned int)RSA_size(rsa)) 185 { 186 RSAerr(RSA_F_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH); 187 return(0); 188 } 189 190 if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) 191 { 192 return rsa->meth->rsa_verify(dtype, m, m_len, 193 sigbuf, siglen, rsa); 194 } 195 196 s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen); 197 if (s == NULL) 198 { 199 RSAerr(RSA_F_RSA_VERIFY,ERR_R_MALLOC_FAILURE); 200 goto err; 201 } 202 if(dtype == NID_md5_sha1) 203 { 204 if (m_len != SSL_SIG_LENGTH) 205 { 206 RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH); 207 goto err; 208 } 209 } 210 /* NB: in FIPS mode block anything that isn't a TLS signature */ 211#ifdef OPENSSL_FIPS 212 else if(FIPS_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) 213 { 214 RSAerr(RSA_F_RSA_VERIFY, RSA_R_OPERATION_NOT_ALLOWED_IN_FIPS_MODE); 215 return 0; 216 } 217 /* Bypass algorithm blocking: this is allowed */ 218 i=rsa->meth->rsa_pub_dec((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING); 219#else 220 i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING); 221#endif 222 223 if (i <= 0) goto err; 224 225 /* Special case: SSL signature */ 226 if(dtype == NID_md5_sha1) { 227 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH)) 228 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 229 else ret = 1; 230 } else { 231 const unsigned char *p=s; 232 sig=d2i_X509_SIG(NULL,&p,(long)i); 233 234 if (sig == NULL) goto err; 235 236 /* Excess data can be used to create forgeries */ 237 if(p != s+i || !rsa_check_digestinfo(sig, s, i)) 238 { 239 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 240 goto err; 241 } 242 243 /* Parameters to the signature algorithm can also be used to 244 create forgeries */ 245 if(sig->algor->parameter 246 && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) 247 { 248 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 249 goto err; 250 } 251 252 sigtype=OBJ_obj2nid(sig->algor->algorithm); 253 254 255 #ifdef RSA_DEBUG 256 /* put a backward compatibility flag in EAY */ 257 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype), 258 OBJ_nid2ln(dtype)); 259 #endif 260 if (sigtype != dtype) 261 { 262 if (((dtype == NID_md5) && 263 (sigtype == NID_md5WithRSAEncryption)) || 264 ((dtype == NID_md2) && 265 (sigtype == NID_md2WithRSAEncryption))) 266 { 267 /* ok, we will let it through */ 268#if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16) 269 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n"); 270#endif 271 } 272 else 273 { 274 RSAerr(RSA_F_RSA_VERIFY, 275 RSA_R_ALGORITHM_MISMATCH); 276 goto err; 277 } 278 } 279 if ( ((unsigned int)sig->digest->length != m_len) || 280 (memcmp(m,sig->digest->data,m_len) != 0)) 281 { 282 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 283 } 284 else 285 ret=1; 286 } 287err: 288 if (sig != NULL) X509_SIG_free(sig); 289 if (s != NULL) 290 { 291 OPENSSL_cleanse(s,(unsigned int)siglen); 292 OPENSSL_free(s); 293 } 294 return(ret); 295 } 296 297