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