1 /* crypto/rsa/rsa_sign.c */ 2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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 #include "rsa_locl.h" 66 67 /* Size of an SSL signature: MD5+SHA1 */ 68 #define SSL_SIG_LENGTH 36 69 70 int RSA_sign(int type, const unsigned char *m, unsigned int m_len, 71 unsigned char *sigret, unsigned int *siglen, RSA *rsa) 72 { 73 X509_SIG sig; 74 ASN1_TYPE parameter; 75 int i,j,ret=1; 76 unsigned char *p, *tmps = NULL; 77 const unsigned char *s = NULL; 78 X509_ALGOR algor; 79 ASN1_OCTET_STRING digest; 80 #ifdef OPENSSL_FIPS 81 if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) 82 && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) 83 { 84 RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD); 85 return 0; 86 } 87 #endif 88 if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) 89 { 90 return rsa->meth->rsa_sign(type, m, m_len, 91 sigret, siglen, rsa); 92 } 93 /* Special case: SSL signature, just check the length */ 94 if(type == NID_md5_sha1) { 95 if(m_len != SSL_SIG_LENGTH) { 96 RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH); 97 return(0); 98 } 99 i = SSL_SIG_LENGTH; 100 s = m; 101 } else { 102 sig.algor= &algor; 103 sig.algor->algorithm=OBJ_nid2obj(type); 104 if (sig.algor->algorithm == NULL) 105 { 106 RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE); 107 return(0); 108 } 109 if (sig.algor->algorithm->length == 0) 110 { 111 RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); 112 return(0); 113 } 114 parameter.type=V_ASN1_NULL; 115 parameter.value.ptr=NULL; 116 sig.algor->parameter= ¶meter; 117 118 sig.digest= &digest; 119 sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */ 120 sig.digest->length=m_len; 121 122 i=i2d_X509_SIG(&sig,NULL); 123 } 124 j=RSA_size(rsa); 125 if (i > (j-RSA_PKCS1_PADDING_SIZE)) 126 { 127 RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); 128 return(0); 129 } 130 if(type != NID_md5_sha1) { 131 tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1); 132 if (tmps == NULL) 133 { 134 RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE); 135 return(0); 136 } 137 p=tmps; 138 i2d_X509_SIG(&sig,&p); 139 s=tmps; 140 } 141 i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING); 142 if (i <= 0) 143 ret=0; 144 else 145 *siglen=i; 146 147 if(type != NID_md5_sha1) { 148 OPENSSL_cleanse(tmps,(unsigned int)j+1); 149 OPENSSL_free(tmps); 150 } 151 return(ret); 152 } 153 154 /* 155 * Check DigestInfo structure does not contain extraneous data by reencoding 156 * using DER and checking encoding against original. 157 */ 158 static int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo, int dinfolen) 159 { 160 unsigned char *der = NULL; 161 int derlen; 162 int ret = 0; 163 derlen = i2d_X509_SIG(sig, &der); 164 if (derlen <= 0) 165 return 0; 166 if (derlen == dinfolen && !memcmp(dinfo, der, derlen)) 167 ret = 1; 168 OPENSSL_cleanse(der, derlen); 169 OPENSSL_free(der); 170 return ret; 171 } 172 173 int int_rsa_verify(int dtype, const unsigned char *m, 174 unsigned int m_len, 175 unsigned char *rm, size_t *prm_len, 176 const unsigned char *sigbuf, size_t siglen, 177 RSA *rsa) 178 { 179 int i,ret=0,sigtype; 180 unsigned char *s; 181 X509_SIG *sig=NULL; 182 183 #ifdef OPENSSL_FIPS 184 if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD) 185 && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) 186 { 187 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD); 188 return 0; 189 } 190 #endif 191 192 if (siglen != (unsigned int)RSA_size(rsa)) 193 { 194 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH); 195 return(0); 196 } 197 198 if((dtype == NID_md5_sha1) && rm) 199 { 200 i = RSA_public_decrypt((int)siglen, 201 sigbuf,rm,rsa,RSA_PKCS1_PADDING); 202 if (i <= 0) 203 return 0; 204 *prm_len = i; 205 return 1; 206 } 207 208 s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen); 209 if (s == NULL) 210 { 211 RSAerr(RSA_F_INT_RSA_VERIFY,ERR_R_MALLOC_FAILURE); 212 goto err; 213 } 214 if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) { 215 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH); 216 goto err; 217 } 218 i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING); 219 220 if (i <= 0) goto err; 221 /* Oddball MDC2 case: signature can be OCTET STRING. 222 * check for correct tag and length octets. 223 */ 224 if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10) 225 { 226 if (rm) 227 { 228 memcpy(rm, s + 2, 16); 229 *prm_len = 16; 230 ret = 1; 231 } 232 else if(memcmp(m, s + 2, 16)) 233 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 234 else 235 ret = 1; 236 } 237 238 /* Special case: SSL signature */ 239 if(dtype == NID_md5_sha1) { 240 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH)) 241 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 242 else ret = 1; 243 } else { 244 const unsigned char *p=s; 245 sig=d2i_X509_SIG(NULL,&p,(long)i); 246 247 if (sig == NULL) goto err; 248 249 /* Excess data can be used to create forgeries */ 250 if(p != s+i || !rsa_check_digestinfo(sig, s, i)) 251 { 252 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 253 goto err; 254 } 255 256 /* Parameters to the signature algorithm can also be used to 257 create forgeries */ 258 if(sig->algor->parameter 259 && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) 260 { 261 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 262 goto err; 263 } 264 265 sigtype=OBJ_obj2nid(sig->algor->algorithm); 266 267 268 #ifdef RSA_DEBUG 269 /* put a backward compatibility flag in EAY */ 270 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype), 271 OBJ_nid2ln(dtype)); 272 #endif 273 if (sigtype != dtype) 274 { 275 if (((dtype == NID_md5) && 276 (sigtype == NID_md5WithRSAEncryption)) || 277 ((dtype == NID_md2) && 278 (sigtype == NID_md2WithRSAEncryption))) 279 { 280 /* ok, we will let it through */ 281 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16) 282 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n"); 283 #endif 284 } 285 else 286 { 287 RSAerr(RSA_F_INT_RSA_VERIFY, 288 RSA_R_ALGORITHM_MISMATCH); 289 goto err; 290 } 291 } 292 if (rm) 293 { 294 const EVP_MD *md; 295 md = EVP_get_digestbynid(dtype); 296 if (md && (EVP_MD_size(md) != sig->digest->length)) 297 RSAerr(RSA_F_INT_RSA_VERIFY, 298 RSA_R_INVALID_DIGEST_LENGTH); 299 else 300 { 301 memcpy(rm, sig->digest->data, 302 sig->digest->length); 303 *prm_len = sig->digest->length; 304 ret = 1; 305 } 306 } 307 else if (((unsigned int)sig->digest->length != m_len) || 308 (memcmp(m,sig->digest->data,m_len) != 0)) 309 { 310 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 311 } 312 else 313 ret=1; 314 } 315 err: 316 if (sig != NULL) X509_SIG_free(sig); 317 if (s != NULL) 318 { 319 OPENSSL_cleanse(s,(unsigned int)siglen); 320 OPENSSL_free(s); 321 } 322 return(ret); 323 } 324 325 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, 326 const unsigned char *sigbuf, unsigned int siglen, 327 RSA *rsa) 328 { 329 330 if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) 331 { 332 return rsa->meth->rsa_verify(dtype, m, m_len, 333 sigbuf, siglen, rsa); 334 } 335 336 return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa); 337 } 338
