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
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 int int_rsa_verify(int dtype, const unsigned char *m,
155 unsigned int m_len,
156 unsigned char *rm, size_t *prm_len,
157 const unsigned char *sigbuf, size_t siglen,
158 RSA *rsa)
159 {
160 int i,ret=0,sigtype;
161 unsigned char *s;
162 X509_SIG *sig=NULL;
163
164 #ifdef OPENSSL_FIPS
165 if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
166 && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW))
167 {
168 RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD);
169 return 0;
170 }
171 #endif
172
173 if (siglen != (unsigned int)RSA_size(rsa))
174 {
175 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
176 return(0);
177 }
178
179 if((dtype == NID_md5_sha1) && rm)
180 {
181 i = RSA_public_decrypt((int)siglen,
182 sigbuf,rm,rsa,RSA_PKCS1_PADDING);
183 if (i <= 0)
184 return 0;
185 *prm_len = i;
186 return 1;
187 }
188
189 s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
190 if (s == NULL)
191 {
192 RSAerr(RSA_F_INT_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
193 goto err;
194 }
195 if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
196 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
197 goto err;
198 }
199 i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
200
201 if (i <= 0) goto err;
202 /* Oddball MDC2 case: signature can be OCTET STRING.
203 * check for correct tag and length octets.
204 */
205 if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10)
206 {
207 if (rm)
208 {
209 memcpy(rm, s + 2, 16);
210 *prm_len = 16;
211 ret = 1;
212 }
213 else if(memcmp(m, s + 2, 16))
214 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
215 else
216 ret = 1;
217 }
218
219 /* Special case: SSL signature */
220 if(dtype == NID_md5_sha1) {
221 if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
222 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
223 else ret = 1;
224 } else {
225 const unsigned char *p=s;
226 sig=d2i_X509_SIG(NULL,&p,(long)i);
227
228 if (sig == NULL) goto err;
229
230 /* Excess data can be used to create forgeries */
231 if(p != s+i)
232 {
233 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
234 goto err;
235 }
236
237 /* Parameters to the signature algorithm can also be used to
238 create forgeries */
239 if(sig->algor->parameter
240 && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)
241 {
242 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
243 goto err;
244 }
245
246 sigtype=OBJ_obj2nid(sig->algor->algorithm);
247
248
249 #ifdef RSA_DEBUG
250 /* put a backward compatibility flag in EAY */
251 fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
252 OBJ_nid2ln(dtype));
253 #endif
254 if (sigtype != dtype)
255 {
256 if (((dtype == NID_md5) &&
257 (sigtype == NID_md5WithRSAEncryption)) ||
258 ((dtype == NID_md2) &&
259 (sigtype == NID_md2WithRSAEncryption)))
260 {
261 /* ok, we will let it through */
262 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
263 fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
264 #endif
265 }
266 else
267 {
268 RSAerr(RSA_F_INT_RSA_VERIFY,
269 RSA_R_ALGORITHM_MISMATCH);
270 goto err;
271 }
272 }
273 if (rm)
274 {
275 const EVP_MD *md;
276 md = EVP_get_digestbynid(dtype);
277 if (md && (EVP_MD_size(md) != sig->digest->length))
278 RSAerr(RSA_F_INT_RSA_VERIFY,
279 RSA_R_INVALID_DIGEST_LENGTH);
280 else
281 {
282 memcpy(rm, sig->digest->data,
283 sig->digest->length);
284 *prm_len = sig->digest->length;
285 ret = 1;
286 }
287 }
288 else if (((unsigned int)sig->digest->length != m_len) ||
289 (memcmp(m,sig->digest->data,m_len) != 0))
290 {
291 RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
292 }
293 else
294 ret=1;
295 }
296 err:
297 if (sig != NULL) X509_SIG_free(sig);
298 if (s != NULL)
299 {
300 OPENSSL_cleanse(s,(unsigned int)siglen);
301 OPENSSL_free(s);
302 }
303 return(ret);
304 }
305
306 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
307 const unsigned char *sigbuf, unsigned int siglen,
308 RSA *rsa)
309 {
310
311 if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
312 {
313 return rsa->meth->rsa_verify(dtype, m, m_len,
314 sigbuf, siglen, rsa);
315 }
316
317 return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
318 }