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
RSA_sign(int type,const unsigned char * m,unsigned int m_len,unsigned char * sigret,unsigned int * siglen,RSA * rsa)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 */
rsa_check_digestinfo(X509_SIG * sig,const unsigned char * dinfo,int dinfolen)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
int_rsa_verify(int dtype,const unsigned char * m,unsigned int m_len,unsigned char * rm,size_t * prm_len,const unsigned char * sigbuf,size_t siglen,RSA * rsa)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
RSA_verify(int dtype,const unsigned char * m,unsigned int m_len,const unsigned char * sigbuf,unsigned int siglen,RSA * rsa)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