Line data Source code
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 :
70 381 : 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 : RSAerr(RSA_F_RSA_SIGN, RSA_R_NON_FIPS_RSA_METHOD);
84 : return 0;
85 : }
86 : #endif
87 381 : if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_sign) {
88 0 : return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa);
89 : }
90 : /* Special case: SSL signature, just check the length */
91 381 : if (type == NID_md5_sha1) {
92 0 : if (m_len != SSL_SIG_LENGTH) {
93 0 : RSAerr(RSA_F_RSA_SIGN, RSA_R_INVALID_MESSAGE_LENGTH);
94 0 : return (0);
95 : }
96 : i = SSL_SIG_LENGTH;
97 : s = m;
98 : } else {
99 381 : sig.algor = &algor;
100 381 : sig.algor->algorithm = OBJ_nid2obj(type);
101 381 : if (sig.algor->algorithm == NULL) {
102 0 : RSAerr(RSA_F_RSA_SIGN, RSA_R_UNKNOWN_ALGORITHM_TYPE);
103 0 : return (0);
104 : }
105 381 : if (sig.algor->algorithm->length == 0) {
106 0 : RSAerr(RSA_F_RSA_SIGN,
107 : RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
108 0 : return (0);
109 : }
110 381 : parameter.type = V_ASN1_NULL;
111 381 : parameter.value.ptr = NULL;
112 381 : sig.algor->parameter = ¶meter;
113 :
114 381 : sig.digest = &digest;
115 381 : sig.digest->data = (unsigned char *)m; /* TMP UGLY CAST */
116 381 : sig.digest->length = m_len;
117 :
118 381 : i = i2d_X509_SIG(&sig, NULL);
119 : }
120 381 : j = RSA_size(rsa);
121 381 : if (i > (j - RSA_PKCS1_PADDING_SIZE)) {
122 0 : RSAerr(RSA_F_RSA_SIGN, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
123 0 : return (0);
124 : }
125 381 : if (type != NID_md5_sha1) {
126 381 : tmps = (unsigned char *)OPENSSL_malloc((unsigned int)j + 1);
127 381 : if (tmps == NULL) {
128 0 : RSAerr(RSA_F_RSA_SIGN, ERR_R_MALLOC_FAILURE);
129 0 : return (0);
130 : }
131 381 : p = tmps;
132 381 : i2d_X509_SIG(&sig, &p);
133 : s = tmps;
134 : }
135 381 : i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);
136 381 : if (i <= 0)
137 : ret = 0;
138 : else
139 381 : *siglen = i;
140 :
141 381 : if (type != NID_md5_sha1) {
142 381 : OPENSSL_cleanse(tmps, (unsigned int)j + 1);
143 381 : OPENSSL_free(tmps);
144 : }
145 381 : return (ret);
146 : }
147 :
148 : /*
149 : * Check DigestInfo structure does not contain extraneous data by reencoding
150 : * using DER and checking encoding against original.
151 : */
152 745 : static int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo,
153 : int dinfolen)
154 : {
155 745 : unsigned char *der = NULL;
156 : int derlen;
157 : int ret = 0;
158 745 : derlen = i2d_X509_SIG(sig, &der);
159 745 : if (derlen <= 0)
160 : return 0;
161 745 : if (derlen == dinfolen && !memcmp(dinfo, der, derlen))
162 : ret = 1;
163 745 : OPENSSL_cleanse(der, derlen);
164 745 : OPENSSL_free(der);
165 745 : return ret;
166 : }
167 :
168 746 : int int_rsa_verify(int dtype, const unsigned char *m,
169 : unsigned int m_len,
170 : unsigned char *rm, size_t *prm_len,
171 : const unsigned char *sigbuf, size_t siglen, RSA *rsa)
172 : {
173 : int i, ret = 0, sigtype;
174 : unsigned char *s;
175 : X509_SIG *sig = NULL;
176 :
177 : #ifdef OPENSSL_FIPS
178 : if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
179 : && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
180 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_NON_FIPS_RSA_METHOD);
181 : return 0;
182 : }
183 : #endif
184 :
185 746 : if (siglen != (unsigned int)RSA_size(rsa)) {
186 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_WRONG_SIGNATURE_LENGTH);
187 0 : return (0);
188 : }
189 :
190 746 : if ((dtype == NID_md5_sha1) && rm) {
191 0 : i = RSA_public_decrypt((int)siglen,
192 : sigbuf, rm, rsa, RSA_PKCS1_PADDING);
193 0 : if (i <= 0)
194 : return 0;
195 0 : *prm_len = i;
196 0 : return 1;
197 : }
198 :
199 746 : s = (unsigned char *)OPENSSL_malloc((unsigned int)siglen);
200 746 : if (s == NULL) {
201 0 : RSAerr(RSA_F_INT_RSA_VERIFY, ERR_R_MALLOC_FAILURE);
202 0 : goto err;
203 : }
204 746 : if ((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH)) {
205 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_MESSAGE_LENGTH);
206 0 : goto err;
207 : }
208 746 : i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING);
209 :
210 746 : if (i <= 0)
211 : goto err;
212 : /*
213 : * Oddball MDC2 case: signature can be OCTET STRING. check for correct
214 : * tag and length octets.
215 : */
216 745 : if (dtype == NID_mdc2 && i == 18 && s[0] == 0x04 && s[1] == 0x10) {
217 0 : if (rm) {
218 0 : memcpy(rm, s + 2, 16);
219 0 : *prm_len = 16;
220 : ret = 1;
221 0 : } else if (memcmp(m, s + 2, 16))
222 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
223 : else
224 : ret = 1;
225 : }
226 :
227 : /* Special case: SSL signature */
228 745 : if (dtype == NID_md5_sha1) {
229 0 : if ((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
230 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
231 : else
232 : ret = 1;
233 : } else {
234 745 : const unsigned char *p = s;
235 745 : sig = d2i_X509_SIG(NULL, &p, (long)i);
236 :
237 745 : if (sig == NULL)
238 : goto err;
239 :
240 : /* Excess data can be used to create forgeries */
241 745 : if (p != s + i || !rsa_check_digestinfo(sig, s, i)) {
242 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
243 0 : goto err;
244 : }
245 :
246 : /*
247 : * Parameters to the signature algorithm can also be used to create
248 : * forgeries
249 : */
250 745 : if (sig->algor->parameter
251 745 : && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL) {
252 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
253 0 : goto err;
254 : }
255 :
256 745 : sigtype = OBJ_obj2nid(sig->algor->algorithm);
257 :
258 : #ifdef RSA_DEBUG
259 : /* put a backward compatibility flag in EAY */
260 : fprintf(stderr, "in(%s) expect(%s)\n", OBJ_nid2ln(sigtype),
261 : OBJ_nid2ln(dtype));
262 : #endif
263 745 : if (sigtype != dtype) {
264 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_ALGORITHM_MISMATCH);
265 0 : goto err;
266 : }
267 745 : if (rm) {
268 : const EVP_MD *md;
269 0 : md = EVP_get_digestbynid(dtype);
270 0 : if (md && (EVP_MD_size(md) != sig->digest->length))
271 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_INVALID_DIGEST_LENGTH);
272 : else {
273 0 : memcpy(rm, sig->digest->data, sig->digest->length);
274 0 : *prm_len = sig->digest->length;
275 : ret = 1;
276 : }
277 1490 : } else if (((unsigned int)sig->digest->length != m_len) ||
278 745 : (memcmp(m, sig->digest->data, m_len) != 0)) {
279 0 : RSAerr(RSA_F_INT_RSA_VERIFY, RSA_R_BAD_SIGNATURE);
280 : } else
281 : ret = 1;
282 : }
283 : err:
284 746 : if (sig != NULL)
285 745 : X509_SIG_free(sig);
286 746 : if (s != NULL) {
287 746 : OPENSSL_cleanse(s, (unsigned int)siglen);
288 746 : OPENSSL_free(s);
289 : }
290 746 : return (ret);
291 : }
292 :
293 746 : int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
294 : const unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
295 : {
296 :
297 746 : if ((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify) {
298 0 : return rsa->meth->rsa_verify(dtype, m, m_len, sigbuf, siglen, rsa);
299 : }
300 :
301 746 : return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
302 : }
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