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 69 int 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 sig.algor= &algor; 94 sig.algor->algorithm=OBJ_nid2obj(type); 95 if (sig.algor->algorithm == NULL) 96 { 97 RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE); 98 return(0); 99 } 100 if (sig.algor->algorithm->length == 0) 101 { 102 RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD); 103 return(0); 104 } 105 parameter.type=V_ASN1_NULL; 106 parameter.value.ptr=NULL; 107 sig.algor->parameter= ¶meter; 108 109 sig.digest= &digest; 110 sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */ 111 sig.digest->length=m_len; 112 113 i=i2d_X509_SIG(&sig,NULL); 114 } 115 j=RSA_size(rsa); 116 if (i > (j-RSA_PKCS1_PADDING_SIZE)) 117 { 118 RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY); 119 return(0); 120 } 121 if(type != NID_md5_sha1) { 122 tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1); 123 if (tmps == NULL) 124 { 125 RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE); 126 return(0); 127 } 128 p=tmps; 129 i2d_X509_SIG(&sig,&p); 130 s=tmps; 131 } 132 i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING); 133 if (i <= 0) 134 ret=0; 135 else 136 *siglen=i; 137 138 if(type != NID_md5_sha1) { 139 OPENSSL_cleanse(tmps,(unsigned int)j+1); 140 OPENSSL_free(tmps); 141 } 142 return(ret); 143 } 144 145 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, 146 unsigned char *sigbuf, unsigned int siglen, RSA *rsa) 147 { 148 int i,ret=0,sigtype; 149 unsigned char *s; 150 X509_SIG *sig=NULL; 151 152 if (siglen != (unsigned int)RSA_size(rsa)) 153 { 154 RSAerr(RSA_F_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH); 155 return(0); 156 } 157 158 if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) 159 { 160 return rsa->meth->rsa_verify(dtype, m, m_len, 161 sigbuf, siglen, rsa); 162 } 163 164 s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen); 165 if (s == NULL) 166 { 167 RSAerr(RSA_F_RSA_VERIFY,ERR_R_MALLOC_FAILURE); 168 goto err; 169 } 170 if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) { 171 RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH); 172 goto err; 173 } 174 i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING); 175 176 if (i <= 0) goto err; 177 178 /* Special case: SSL signature */ 179 if(dtype == NID_md5_sha1) { 180 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH)) 181 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 182 else ret = 1; 183 } else { 184 const unsigned char *p=s; 185 sig=d2i_X509_SIG(NULL,&p,(long)i); 186 187 if (sig == NULL) goto err; 188 189 /* Excess data can be used to create forgeries */ 190 if(p != s+i) 191 { 192 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 193 goto err; 194 } 195 196 /* Parameters to the signature algorithm can also be used to 197 create forgeries */ 198 if(sig->algor->parameter 199 && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) 200 { 201 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 202 goto err; 203 } 204 205 sigtype=OBJ_obj2nid(sig->algor->algorithm); 206 207 208 #ifdef RSA_DEBUG 209 /* put a backward compatibility flag in EAY */ 210 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype), 211 OBJ_nid2ln(dtype)); 212 #endif 213 if (sigtype != dtype) 214 { 215 if (((dtype == NID_md5) && 216 (sigtype == NID_md5WithRSAEncryption)) || 217 ((dtype == NID_md2) && 218 (sigtype == NID_md2WithRSAEncryption))) 219 { 220 /* ok, we will let it through */ 221 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16) 222 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n"); 223 #endif 224 } 225 else 226 { 227 RSAerr(RSA_F_RSA_VERIFY, 228 RSA_R_ALGORITHM_MISMATCH); 229 goto err; 230 } 231 } 232 if ( ((unsigned int)sig->digest->length != m_len) || 233 (memcmp(m,sig->digest->data,m_len) != 0)) 234 { 235 RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); 236 } 237 else 238 ret=1; 239 } 240 err: 241 if (sig != NULL) X509_SIG_free(sig); 242 if (s != NULL) 243 { 244 OPENSSL_cleanse(s,(unsigned int)siglen); 245 OPENSSL_free(s); 246 } 247 return(ret); 248 } 249 250