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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 	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= &parameter;
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 
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)146 int int_rsa_verify(int dtype, const unsigned char *m,
147 			  unsigned int m_len,
148 			  unsigned char *rm, size_t *prm_len,
149 			  const unsigned char *sigbuf, size_t siglen,
150 			  RSA *rsa)
151 	{
152 	int i,ret=0,sigtype;
153 	unsigned char *s;
154 	X509_SIG *sig=NULL;
155 
156 	if (siglen != (unsigned int)RSA_size(rsa))
157 		{
158 		RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
159 		return(0);
160 		}
161 
162 	if((dtype == NID_md5_sha1) && rm)
163 		{
164 		i = RSA_public_decrypt((int)siglen,
165 					sigbuf,rm,rsa,RSA_PKCS1_PADDING);
166 		if (i <= 0)
167 			return 0;
168 		*prm_len = i;
169 		return 1;
170 		}
171 
172 	s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
173 	if (s == NULL)
174 		{
175 		RSAerr(RSA_F_INT_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
176 		goto err;
177 		}
178 	if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
179 			RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
180 			goto err;
181 	}
182 	i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
183 
184 	if (i <= 0) goto err;
185 
186 	/* Special case: SSL signature */
187 	if(dtype == NID_md5_sha1) {
188 		if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
189 				RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
190 		else ret = 1;
191 	} else {
192 		const unsigned char *p=s;
193 		sig=d2i_X509_SIG(NULL,&p,(long)i);
194 
195 		if (sig == NULL) goto err;
196 
197 		/* Excess data can be used to create forgeries */
198 		if(p != s+i)
199 			{
200 			RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
201 			goto err;
202 			}
203 
204 		/* Parameters to the signature algorithm can also be used to
205 		   create forgeries */
206 		if(sig->algor->parameter
207 		   && ASN1_TYPE_get(sig->algor->parameter) != V_ASN1_NULL)
208 			{
209 			RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
210 			goto err;
211 			}
212 
213 		sigtype=OBJ_obj2nid(sig->algor->algorithm);
214 
215 
216 	#ifdef RSA_DEBUG
217 		/* put a backward compatibility flag in EAY */
218 		fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
219 			OBJ_nid2ln(dtype));
220 	#endif
221 		if (sigtype != dtype)
222 			{
223 			if (((dtype == NID_md5) &&
224 				(sigtype == NID_md5WithRSAEncryption)) ||
225 				((dtype == NID_md2) &&
226 				(sigtype == NID_md2WithRSAEncryption)))
227 				{
228 				/* ok, we will let it through */
229 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
230 				fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
231 #endif
232 				}
233 			else
234 				{
235 				RSAerr(RSA_F_INT_RSA_VERIFY,
236 						RSA_R_ALGORITHM_MISMATCH);
237 				goto err;
238 				}
239 			}
240 		if (rm)
241 			{
242 			const EVP_MD *md;
243 			md = EVP_get_digestbynid(dtype);
244 			if (md && (EVP_MD_size(md) != sig->digest->length))
245 				RSAerr(RSA_F_INT_RSA_VERIFY,
246 						RSA_R_INVALID_DIGEST_LENGTH);
247 			else
248 				{
249 				memcpy(rm, sig->digest->data,
250 							sig->digest->length);
251 				*prm_len = sig->digest->length;
252 				ret = 1;
253 				}
254 			}
255 		else if (((unsigned int)sig->digest->length != m_len) ||
256 			(memcmp(m,sig->digest->data,m_len) != 0))
257 			{
258 			RSAerr(RSA_F_INT_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
259 			}
260 		else
261 			ret=1;
262 	}
263 err:
264 	if (sig != NULL) X509_SIG_free(sig);
265 	if (s != NULL)
266 		{
267 		OPENSSL_cleanse(s,(unsigned int)siglen);
268 		OPENSSL_free(s);
269 		}
270 	return(ret);
271 	}
272 
RSA_verify(int dtype,const unsigned char * m,unsigned int m_len,const unsigned char * sigbuf,unsigned int siglen,RSA * rsa)273 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
274 		const unsigned char *sigbuf, unsigned int siglen,
275 		RSA *rsa)
276 	{
277 
278 	if((rsa->flags & RSA_FLAG_SIGN_VER) && rsa->meth->rsa_verify)
279 		{
280 		return rsa->meth->rsa_verify(dtype, m, m_len,
281 			sigbuf, siglen, rsa);
282 		}
283 
284 	return int_rsa_verify(dtype, m, m_len, NULL, NULL, sigbuf, siglen, rsa);
285 	}
286