1 /* crypto/rsa/rsa_sign.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
60 #include "internal/cryptlib.h"
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/objects.h>
64 #include <openssl/x509.h>
67 /* Size of an SSL signature: MD5+SHA1 */
68 #define SSL_SIG_LENGTH 36
70 int RSA_sign(int type
, const unsigned char *m
, unsigned int m_len
,
71 unsigned char *sigret
, unsigned int *siglen
, RSA
*rsa
)
76 unsigned char *p
, *tmps
= NULL
;
77 const unsigned char *s
= NULL
;
79 ASN1_OCTET_STRING digest
;
80 if ((rsa
->flags
& RSA_FLAG_SIGN_VER
) && rsa
->meth
->rsa_sign
) {
81 return rsa
->meth
->rsa_sign(type
, m
, m_len
, sigret
, siglen
, rsa
);
83 /* Special case: SSL signature, just check the length */
84 if (type
== NID_md5_sha1
) {
85 if (m_len
!= SSL_SIG_LENGTH
) {
86 RSAerr(RSA_F_RSA_SIGN
, RSA_R_INVALID_MESSAGE_LENGTH
);
93 sig
.algor
->algorithm
= OBJ_nid2obj(type
);
94 if (sig
.algor
->algorithm
== NULL
) {
95 RSAerr(RSA_F_RSA_SIGN
, RSA_R_UNKNOWN_ALGORITHM_TYPE
);
98 if (OBJ_length(sig
.algor
->algorithm
) == 0) {
99 RSAerr(RSA_F_RSA_SIGN
,
100 RSA_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD
);
103 parameter
.type
= V_ASN1_NULL
;
104 parameter
.value
.ptr
= NULL
;
105 sig
.algor
->parameter
= ¶meter
;
107 sig
.digest
= &digest
;
108 sig
.digest
->data
= (unsigned char *)m
; /* TMP UGLY CAST */
109 sig
.digest
->length
= m_len
;
111 i
= i2d_X509_SIG(&sig
, NULL
);
114 if (i
> (j
- RSA_PKCS1_PADDING_SIZE
)) {
115 RSAerr(RSA_F_RSA_SIGN
, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY
);
118 if (type
!= NID_md5_sha1
) {
119 tmps
= OPENSSL_malloc((unsigned int)j
+ 1);
121 RSAerr(RSA_F_RSA_SIGN
, ERR_R_MALLOC_FAILURE
);
125 i2d_X509_SIG(&sig
, &p
);
128 i
= RSA_private_encrypt(i
, s
, sigret
, rsa
, RSA_PKCS1_PADDING
);
134 if (type
!= NID_md5_sha1
)
135 OPENSSL_clear_free(tmps
, (unsigned int)j
+ 1);
140 * Check DigestInfo structure does not contain extraneous data by reencoding
141 * using DER and checking encoding against original.
143 static int rsa_check_digestinfo(X509_SIG
*sig
, const unsigned char *dinfo
,
146 unsigned char *der
= NULL
;
149 derlen
= i2d_X509_SIG(sig
, &der
);
152 if (derlen
== dinfolen
&& !memcmp(dinfo
, der
, derlen
))
154 OPENSSL_clear_free(der
, derlen
);
158 int int_rsa_verify(int dtype
, const unsigned char *m
,
160 unsigned char *rm
, size_t *prm_len
,
161 const unsigned char *sigbuf
, size_t siglen
, RSA
*rsa
)
163 int i
, ret
= 0, sigtype
;
165 X509_SIG
*sig
= NULL
;
167 if (siglen
!= (unsigned int)RSA_size(rsa
)) {
168 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_WRONG_SIGNATURE_LENGTH
);
172 if ((dtype
== NID_md5_sha1
) && rm
) {
173 i
= RSA_public_decrypt((int)siglen
,
174 sigbuf
, rm
, rsa
, RSA_PKCS1_PADDING
);
181 s
= OPENSSL_malloc((unsigned int)siglen
);
183 RSAerr(RSA_F_INT_RSA_VERIFY
, ERR_R_MALLOC_FAILURE
);
186 if ((dtype
== NID_md5_sha1
) && (m_len
!= SSL_SIG_LENGTH
)) {
187 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_INVALID_MESSAGE_LENGTH
);
190 i
= RSA_public_decrypt((int)siglen
, sigbuf
, s
, rsa
, RSA_PKCS1_PADDING
);
195 * Oddball MDC2 case: signature can be OCTET STRING. check for correct
196 * tag and length octets.
198 if (dtype
== NID_mdc2
&& i
== 18 && s
[0] == 0x04 && s
[1] == 0x10) {
200 memcpy(rm
, s
+ 2, 16);
203 } else if (memcmp(m
, s
+ 2, 16)) {
204 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_BAD_SIGNATURE
);
208 } else if (dtype
== NID_md5_sha1
) {
209 /* Special case: SSL signature */
210 if ((i
!= SSL_SIG_LENGTH
) || memcmp(s
, m
, SSL_SIG_LENGTH
))
211 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_BAD_SIGNATURE
);
215 const unsigned char *p
= s
;
216 sig
= d2i_X509_SIG(NULL
, &p
, (long)i
);
221 /* Excess data can be used to create forgeries */
222 if (p
!= s
+ i
|| !rsa_check_digestinfo(sig
, s
, i
)) {
223 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_BAD_SIGNATURE
);
228 * Parameters to the signature algorithm can also be used to create
231 if (sig
->algor
->parameter
232 && ASN1_TYPE_get(sig
->algor
->parameter
) != V_ASN1_NULL
) {
233 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_BAD_SIGNATURE
);
237 sigtype
= OBJ_obj2nid(sig
->algor
->algorithm
);
240 /* put a backward compatibility flag in EAY */
241 fprintf(stderr
, "in(%s) expect(%s)\n", OBJ_nid2ln(sigtype
),
244 if (sigtype
!= dtype
) {
245 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_ALGORITHM_MISMATCH
);
250 md
= EVP_get_digestbynid(dtype
);
251 if (md
&& (EVP_MD_size(md
) != sig
->digest
->length
))
252 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_INVALID_DIGEST_LENGTH
);
254 memcpy(rm
, sig
->digest
->data
, sig
->digest
->length
);
255 *prm_len
= sig
->digest
->length
;
258 } else if (((unsigned int)sig
->digest
->length
!= m_len
) ||
259 (memcmp(m
, sig
->digest
->data
, m_len
) != 0)) {
260 RSAerr(RSA_F_INT_RSA_VERIFY
, RSA_R_BAD_SIGNATURE
);
266 OPENSSL_clear_free(s
, (unsigned int)siglen
);
270 int RSA_verify(int dtype
, const unsigned char *m
, unsigned int m_len
,
271 const unsigned char *sigbuf
, unsigned int siglen
, RSA
*rsa
)
274 if ((rsa
->flags
& RSA_FLAG_SIGN_VER
) && rsa
->meth
->rsa_verify
) {
275 return rsa
->meth
->rsa_verify(dtype
, m
, m_len
, sigbuf
, siglen
, rsa
);
278 return int_rsa_verify(dtype
, m
, m_len
, NULL
, NULL
, sigbuf
, siglen
, rsa
);