xref: /freebsd/crypto/openssl/crypto/rsa/rsa_sign.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
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 #ifndef OPENSSL_NO_ENGINE
66 #include <openssl/engine.h>
67 #endif
68 
69 /* Size of an SSL signature: MD5+SHA1 */
70 #define SSL_SIG_LENGTH	36
71 
72 int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
73 	     unsigned char *sigret, unsigned int *siglen, RSA *rsa)
74 	{
75 	X509_SIG sig;
76 	ASN1_TYPE parameter;
77 	int i,j,ret=1;
78 	unsigned char *p, *tmps = NULL;
79 	const unsigned char *s = NULL;
80 	X509_ALGOR algor;
81 	ASN1_OCTET_STRING digest;
82 #ifndef OPENSSL_NO_ENGINE
83 	if((rsa->flags & RSA_FLAG_SIGN_VER)
84 	      && ENGINE_get_RSA(rsa->engine)->rsa_sign)
85 	      return ENGINE_get_RSA(rsa->engine)->rsa_sign(type,
86 			m, m_len, sigret, siglen, rsa);
87 #endif
88 	/* Special case: SSL signature, just check the length */
89 	if(type == NID_md5_sha1) {
90 		if(m_len != SSL_SIG_LENGTH) {
91 			RSAerr(RSA_F_RSA_SIGN,RSA_R_INVALID_MESSAGE_LENGTH);
92 			return(0);
93 		}
94 		i = SSL_SIG_LENGTH;
95 		s = m;
96 	} else {
97 		sig.algor= &algor;
98 		sig.algor->algorithm=OBJ_nid2obj(type);
99 		if (sig.algor->algorithm == NULL)
100 			{
101 			RSAerr(RSA_F_RSA_SIGN,RSA_R_UNKNOWN_ALGORITHM_TYPE);
102 			return(0);
103 			}
104 		if (sig.algor->algorithm->length == 0)
105 			{
106 			RSAerr(RSA_F_RSA_SIGN,RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);
107 			return(0);
108 			}
109 		parameter.type=V_ASN1_NULL;
110 		parameter.value.ptr=NULL;
111 		sig.algor->parameter= &parameter;
112 
113 		sig.digest= &digest;
114 		sig.digest->data=(unsigned char *)m; /* TMP UGLY CAST */
115 		sig.digest->length=m_len;
116 
117 		i=i2d_X509_SIG(&sig,NULL);
118 	}
119 	j=RSA_size(rsa);
120 	if (i > (j-RSA_PKCS1_PADDING_SIZE))
121 		{
122 		RSAerr(RSA_F_RSA_SIGN,RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);
123 		return(0);
124 		}
125 	if(type != NID_md5_sha1) {
126 		tmps=(unsigned char *)OPENSSL_malloc((unsigned int)j+1);
127 		if (tmps == NULL)
128 			{
129 			RSAerr(RSA_F_RSA_SIGN,ERR_R_MALLOC_FAILURE);
130 			return(0);
131 			}
132 		p=tmps;
133 		i2d_X509_SIG(&sig,&p);
134 		s=tmps;
135 	}
136 	i=RSA_private_encrypt(i,s,sigret,rsa,RSA_PKCS1_PADDING);
137 	if (i <= 0)
138 		ret=0;
139 	else
140 		*siglen=i;
141 
142 	if(type != NID_md5_sha1) {
143 		OPENSSL_cleanse(tmps,(unsigned int)j+1);
144 		OPENSSL_free(tmps);
145 	}
146 	return(ret);
147 	}
148 
149 int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len,
150 	     unsigned char *sigbuf, unsigned int siglen, RSA *rsa)
151 	{
152 	int i,ret=0,sigtype;
153 	unsigned char *p,*s;
154 	X509_SIG *sig=NULL;
155 
156 	if (siglen != (unsigned int)RSA_size(rsa))
157 		{
158 		RSAerr(RSA_F_RSA_VERIFY,RSA_R_WRONG_SIGNATURE_LENGTH);
159 		return(0);
160 		}
161 
162 #ifndef OPENSSL_NO_ENGINE
163 	if((rsa->flags & RSA_FLAG_SIGN_VER)
164 	    && ENGINE_get_RSA(rsa->engine)->rsa_verify)
165 	    return ENGINE_get_RSA(rsa->engine)->rsa_verify(dtype,
166 			m, m_len, sigbuf, siglen, rsa);
167 #endif
168 
169 	s=(unsigned char *)OPENSSL_malloc((unsigned int)siglen);
170 	if (s == NULL)
171 		{
172 		RSAerr(RSA_F_RSA_VERIFY,ERR_R_MALLOC_FAILURE);
173 		goto err;
174 		}
175 	if((dtype == NID_md5_sha1) && (m_len != SSL_SIG_LENGTH) ) {
176 			RSAerr(RSA_F_RSA_VERIFY,RSA_R_INVALID_MESSAGE_LENGTH);
177 			return(0);
178 	}
179 	i=RSA_public_decrypt((int)siglen,sigbuf,s,rsa,RSA_PKCS1_PADDING);
180 
181 	if (i <= 0) goto err;
182 
183 	/* Special case: SSL signature */
184 	if(dtype == NID_md5_sha1) {
185 		if((i != SSL_SIG_LENGTH) || memcmp(s, m, SSL_SIG_LENGTH))
186 				RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
187 		else ret = 1;
188 	} else {
189 		p=s;
190 		sig=d2i_X509_SIG(NULL,&p,(long)i);
191 
192 		if (sig == NULL) goto err;
193 		sigtype=OBJ_obj2nid(sig->algor->algorithm);
194 
195 
196 	#ifdef RSA_DEBUG
197 		/* put a backward compatibility flag in EAY */
198 		fprintf(stderr,"in(%s) expect(%s)\n",OBJ_nid2ln(sigtype),
199 			OBJ_nid2ln(dtype));
200 	#endif
201 		if (sigtype != dtype)
202 			{
203 			if (((dtype == NID_md5) &&
204 				(sigtype == NID_md5WithRSAEncryption)) ||
205 				((dtype == NID_md2) &&
206 				(sigtype == NID_md2WithRSAEncryption)))
207 				{
208 				/* ok, we will let it through */
209 #if !defined(OPENSSL_NO_STDIO) && !defined(OPENSSL_SYS_WIN16)
210 				fprintf(stderr,"signature has problems, re-make with post SSLeay045\n");
211 #endif
212 				}
213 			else
214 				{
215 				RSAerr(RSA_F_RSA_VERIFY,
216 						RSA_R_ALGORITHM_MISMATCH);
217 				goto err;
218 				}
219 			}
220 		if (	((unsigned int)sig->digest->length != m_len) ||
221 			(memcmp(m,sig->digest->data,m_len) != 0))
222 			{
223 			RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE);
224 			}
225 		else
226 			ret=1;
227 	}
228 err:
229 	if (sig != NULL) X509_SIG_free(sig);
230 	OPENSSL_cleanse(s,(unsigned int)siglen);
231 	OPENSSL_free(s);
232 	return(ret);
233 	}
234 
235