xref: /freebsd/crypto/openssl/crypto/rsa/rsa_sign.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
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, 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,*s = NULL;
76 	X509_ALGOR algor;
77 	ASN1_OCTET_STRING digest;
78 	if(rsa->flags & RSA_FLAG_SIGN_VER)
79 	      return rsa->meth->rsa_sign(type, m, m_len, sigret, siglen, rsa);
80 	/* Special case: SSL signature, just check the length */
81 	if(type == NID_md5_sha1) {
82 		if(m_len != SSL_SIG_LENGTH) {
83 			RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);
84 			return(0);
85 		}
86 		i = SSL_SIG_LENGTH;
87 		s = m;
88 	} else {
89 		sig.algor= &algor;
90 		sig.algor->algorithm=OBJ_nid2obj(type);
91 		if (sig.algor->algorithm == NULL)
92 			{
93 			RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);
94 			return(0);
95 			}
96 		if (sig.algor->algorithm->length == 0)
97 			{
98 			RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
99 			return(0);
100 			}
101 		parameter.type=V_ASN1_NULL;
102 		parameter.value.ptr=NULL;
103 		sig.algor->parameter= &parameter;
104 
105 		sig.digest= &digest;
106 		sig.digest->data=m;
107 		sig.digest->length=m_len;
108 
109 		i=i2d_X509_SIG(&sig,NULL);
110 	}
111 	j=RSA_size(rsa);
112 	if ((i-RSA_PKCS1_PADDING) > j)
113 		{
114 		RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
115 		return(0);
116 		}
117 	if(type != NID_md5_sha1) {
118 		s=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);
119 		if (s == NULL)
120 			{
121 			RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);
122 			return(0);
123 			}
124 		p=s;
125 		i2d_X509_SIG(&sig,&p);
126 	}
127 	i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);
128 	if (i <= 0)
129 		ret=0;
130 	else
131 		*siglen=i;
132 
133 	if(type != NID_md5_sha1) {
134 		memset(s,0,(unsigned int)j+1);
135 		OPENSSL_free(s);
136 	}
137 	return(ret);
138 	}
139 
140 int RSA_verify(int dtype, unsigned char *m, unsigned int m_len,
141 	     unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
142 	{
143 	int i,ret=0,sigtype;
144 	unsigned char *p,*s;
145 	X509_SIG *sig=NULL;
146 
147 	if (siglen != (unsigned int)RSA_size(rsa))
148 		{
149 		RSAerr(RSA_F_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
150 		return(0);
151 		}
152 
153 	if(rsa->flags & RSA_FLAG_SIGN_VER)
154 	    return rsa->meth->rsa_verify(dtype, m, m_len, sigbuf, siglen, rsa);
155 
156 	s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
157 	if (s == NULL)
158 		{
159 		RSAerr(RSA_F_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
160 		goto err;
161 		}
162 	if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
163 			RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
164 			return(0);
165 	}
166 	i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
167 
168 	if (i <= 0) goto err;
169 
170 	/* Special case: SSL signature */
171 	if(dtype == NID_md5_sha1) {
172 		if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
173 				RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
174 		else ret = 1;
175 	} else {
176 		p=s;
177 		sig=d2i_X509_SIG(NULL,&p,(long)i);
178 
179 		if (sig == NULL) goto err;
180 		sigtype=OBJ_obj2nid(sig->algor->algorithm);
181 
182 
183 	#ifdef RSA_DEBUG
184 		/* put a backward compatibility flag in EAY */
185 		fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
186 			OBJ_nid2ln(dtype));
187 	#endif
188 		if (sigtype != dtype)
189 			{
190 			if (((dtype == NID_md5) &&
191 				(sigtype == NID_md5WithRSAEncryption)) ||
192 				((dtype == NID_md2) &&
193 				(sigtype == NID_md2WithRSAEncryption)))
194 				{
195 				/* ok, we will let it through */
196 	#if !defined(NO_STDIO) && !defined(WIN16)
197 				fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
198 	#endif
199 				}
200 			else
201 				{
202 				RSAerr(RSA_F_RSA_VERIFY,
203 						RSA_R_ALGORITHM_MISMATCH);
204 				goto err;
205 				}
206 			}
207 		if (	((unsigned int)sig->digest->length != m_len) ||
208 			(memcmp(m,sig->digest->data,m_len) != 0))
209 			{
210 			RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
211 			}
212 		else
213 			ret=1;
214 	}
215 err:
216 	if (sig != NULL) X509_SIG_free(sig);
217 	memset(s,0,(unsigned int)siglen);
218 	OPENSSL_free(s);
219 	return(ret);
220 	}
221 
222