1/* $OpenBSD: ssh-dss.c,v 1.25 2010/02/26 20:29:54 djm Exp $ */
| 1/* $OpenBSD: ssh-dss.c,v 1.26 2010/04/16 01:47:26 djm Exp $ */
|
2/*
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27
28#include <sys/types.h>
29
30#include <openssl/bn.h>
31#include <openssl/evp.h>
32
33#include <stdarg.h>
34#include <string.h>
35
36#include "xmalloc.h"
37#include "buffer.h"
38#include "compat.h"
39#include "log.h"
40#include "key.h"
41
42#define INTBLOB_LEN 20
43#define SIGBLOB_LEN (2*INTBLOB_LEN)
44
45int
46ssh_dss_sign(const Key *key, u_char **sigp, u_int *lenp,
47 const u_char *data, u_int datalen)
48{
49 DSA_SIG *sig;
50 const EVP_MD *evp_md = EVP_sha1();
51 EVP_MD_CTX md;
52 u_char digest[EVP_MAX_MD_SIZE], sigblob[SIGBLOB_LEN];
53 u_int rlen, slen, len, dlen;
54 Buffer b;
55
| 2/*
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27
28#include <sys/types.h>
29
30#include <openssl/bn.h>
31#include <openssl/evp.h>
32
33#include <stdarg.h>
34#include <string.h>
35
36#include "xmalloc.h"
37#include "buffer.h"
38#include "compat.h"
39#include "log.h"
40#include "key.h"
41
42#define INTBLOB_LEN 20
43#define SIGBLOB_LEN (2*INTBLOB_LEN)
44
45int
46ssh_dss_sign(const Key *key, u_char **sigp, u_int *lenp,
47 const u_char *data, u_int datalen)
48{
49 DSA_SIG *sig;
50 const EVP_MD *evp_md = EVP_sha1();
51 EVP_MD_CTX md;
52 u_char digest[EVP_MAX_MD_SIZE], sigblob[SIGBLOB_LEN];
53 u_int rlen, slen, len, dlen;
54 Buffer b;
55
|
56 if (key == NULL ||
57 (key->type != KEY_DSA && key->type != KEY_DSA_CERT) ||
58 key->dsa == NULL) {
| 56 if (key == NULL || key->dsa == NULL || (key->type != KEY_DSA &&
57 key->type != KEY_DSA_CERT && key->type != KEY_DSA_CERT_V00)) {
|
59 error("ssh_dss_sign: no DSA key");
60 return -1;
61 }
62 EVP_DigestInit(&md, evp_md);
63 EVP_DigestUpdate(&md, data, datalen);
64 EVP_DigestFinal(&md, digest, &dlen);
65
66 sig = DSA_do_sign(digest, dlen, key->dsa);
67 memset(digest, 'd', sizeof(digest));
68
69 if (sig == NULL) {
70 error("ssh_dss_sign: sign failed");
71 return -1;
72 }
73
74 rlen = BN_num_bytes(sig->r);
75 slen = BN_num_bytes(sig->s);
76 if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
77 error("bad sig size %u %u", rlen, slen);
78 DSA_SIG_free(sig);
79 return -1;
80 }
81 memset(sigblob, 0, SIGBLOB_LEN);
82 BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
83 BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
84 DSA_SIG_free(sig);
85
86 if (datafellows & SSH_BUG_SIGBLOB) {
87 if (lenp != NULL)
88 *lenp = SIGBLOB_LEN;
89 if (sigp != NULL) {
90 *sigp = xmalloc(SIGBLOB_LEN);
91 memcpy(*sigp, sigblob, SIGBLOB_LEN);
92 }
93 } else {
94 /* ietf-drafts */
95 buffer_init(&b);
96 buffer_put_cstring(&b, "ssh-dss");
97 buffer_put_string(&b, sigblob, SIGBLOB_LEN);
98 len = buffer_len(&b);
99 if (lenp != NULL)
100 *lenp = len;
101 if (sigp != NULL) {
102 *sigp = xmalloc(len);
103 memcpy(*sigp, buffer_ptr(&b), len);
104 }
105 buffer_free(&b);
106 }
107 return 0;
108}
109int
110ssh_dss_verify(const Key *key, const u_char *signature, u_int signaturelen,
111 const u_char *data, u_int datalen)
112{
113 DSA_SIG *sig;
114 const EVP_MD *evp_md = EVP_sha1();
115 EVP_MD_CTX md;
116 u_char digest[EVP_MAX_MD_SIZE], *sigblob;
117 u_int len, dlen;
118 int rlen, ret;
119 Buffer b;
120
| 58 error("ssh_dss_sign: no DSA key");
59 return -1;
60 }
61 EVP_DigestInit(&md, evp_md);
62 EVP_DigestUpdate(&md, data, datalen);
63 EVP_DigestFinal(&md, digest, &dlen);
64
65 sig = DSA_do_sign(digest, dlen, key->dsa);
66 memset(digest, 'd', sizeof(digest));
67
68 if (sig == NULL) {
69 error("ssh_dss_sign: sign failed");
70 return -1;
71 }
72
73 rlen = BN_num_bytes(sig->r);
74 slen = BN_num_bytes(sig->s);
75 if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
76 error("bad sig size %u %u", rlen, slen);
77 DSA_SIG_free(sig);
78 return -1;
79 }
80 memset(sigblob, 0, SIGBLOB_LEN);
81 BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
82 BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
83 DSA_SIG_free(sig);
84
85 if (datafellows & SSH_BUG_SIGBLOB) {
86 if (lenp != NULL)
87 *lenp = SIGBLOB_LEN;
88 if (sigp != NULL) {
89 *sigp = xmalloc(SIGBLOB_LEN);
90 memcpy(*sigp, sigblob, SIGBLOB_LEN);
91 }
92 } else {
93 /* ietf-drafts */
94 buffer_init(&b);
95 buffer_put_cstring(&b, "ssh-dss");
96 buffer_put_string(&b, sigblob, SIGBLOB_LEN);
97 len = buffer_len(&b);
98 if (lenp != NULL)
99 *lenp = len;
100 if (sigp != NULL) {
101 *sigp = xmalloc(len);
102 memcpy(*sigp, buffer_ptr(&b), len);
103 }
104 buffer_free(&b);
105 }
106 return 0;
107}
108int
109ssh_dss_verify(const Key *key, const u_char *signature, u_int signaturelen,
110 const u_char *data, u_int datalen)
111{
112 DSA_SIG *sig;
113 const EVP_MD *evp_md = EVP_sha1();
114 EVP_MD_CTX md;
115 u_char digest[EVP_MAX_MD_SIZE], *sigblob;
116 u_int len, dlen;
117 int rlen, ret;
118 Buffer b;
119
|
121 if (key == NULL ||
122 (key->type != KEY_DSA && key->type != KEY_DSA_CERT) ||
123 key->dsa == NULL) {
| 120 if (key == NULL || key->dsa == NULL || (key->type != KEY_DSA &&
121 key->type != KEY_DSA_CERT && key->type != KEY_DSA_CERT_V00)) {
|
124 error("ssh_dss_verify: no DSA key");
125 return -1;
126 }
127
128 /* fetch signature */
129 if (datafellows & SSH_BUG_SIGBLOB) {
130 sigblob = xmalloc(signaturelen);
131 memcpy(sigblob, signature, signaturelen);
132 len = signaturelen;
133 } else {
134 /* ietf-drafts */
135 char *ktype;
136 buffer_init(&b);
137 buffer_append(&b, signature, signaturelen);
138 ktype = buffer_get_string(&b, NULL);
139 if (strcmp("ssh-dss", ktype) != 0) {
140 error("ssh_dss_verify: cannot handle type %s", ktype);
141 buffer_free(&b);
142 xfree(ktype);
143 return -1;
144 }
145 xfree(ktype);
146 sigblob = buffer_get_string(&b, &len);
147 rlen = buffer_len(&b);
148 buffer_free(&b);
149 if (rlen != 0) {
150 error("ssh_dss_verify: "
151 "remaining bytes in signature %d", rlen);
152 xfree(sigblob);
153 return -1;
154 }
155 }
156
157 if (len != SIGBLOB_LEN) {
158 fatal("bad sigbloblen %u != SIGBLOB_LEN", len);
159 }
160
161 /* parse signature */
162 if ((sig = DSA_SIG_new()) == NULL)
163 fatal("ssh_dss_verify: DSA_SIG_new failed");
164 if ((sig->r = BN_new()) == NULL)
165 fatal("ssh_dss_verify: BN_new failed");
166 if ((sig->s = BN_new()) == NULL)
167 fatal("ssh_dss_verify: BN_new failed");
168 if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) ||
169 (BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL))
170 fatal("ssh_dss_verify: BN_bin2bn failed");
171
172 /* clean up */
173 memset(sigblob, 0, len);
174 xfree(sigblob);
175
176 /* sha1 the data */
177 EVP_DigestInit(&md, evp_md);
178 EVP_DigestUpdate(&md, data, datalen);
179 EVP_DigestFinal(&md, digest, &dlen);
180
181 ret = DSA_do_verify(digest, dlen, sig, key->dsa);
182 memset(digest, 'd', sizeof(digest));
183
184 DSA_SIG_free(sig);
185
186 debug("ssh_dss_verify: signature %s",
187 ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
188 return ret;
189}
| 122 error("ssh_dss_verify: no DSA key");
123 return -1;
124 }
125
126 /* fetch signature */
127 if (datafellows & SSH_BUG_SIGBLOB) {
128 sigblob = xmalloc(signaturelen);
129 memcpy(sigblob, signature, signaturelen);
130 len = signaturelen;
131 } else {
132 /* ietf-drafts */
133 char *ktype;
134 buffer_init(&b);
135 buffer_append(&b, signature, signaturelen);
136 ktype = buffer_get_string(&b, NULL);
137 if (strcmp("ssh-dss", ktype) != 0) {
138 error("ssh_dss_verify: cannot handle type %s", ktype);
139 buffer_free(&b);
140 xfree(ktype);
141 return -1;
142 }
143 xfree(ktype);
144 sigblob = buffer_get_string(&b, &len);
145 rlen = buffer_len(&b);
146 buffer_free(&b);
147 if (rlen != 0) {
148 error("ssh_dss_verify: "
149 "remaining bytes in signature %d", rlen);
150 xfree(sigblob);
151 return -1;
152 }
153 }
154
155 if (len != SIGBLOB_LEN) {
156 fatal("bad sigbloblen %u != SIGBLOB_LEN", len);
157 }
158
159 /* parse signature */
160 if ((sig = DSA_SIG_new()) == NULL)
161 fatal("ssh_dss_verify: DSA_SIG_new failed");
162 if ((sig->r = BN_new()) == NULL)
163 fatal("ssh_dss_verify: BN_new failed");
164 if ((sig->s = BN_new()) == NULL)
165 fatal("ssh_dss_verify: BN_new failed");
166 if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) ||
167 (BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL))
168 fatal("ssh_dss_verify: BN_bin2bn failed");
169
170 /* clean up */
171 memset(sigblob, 0, len);
172 xfree(sigblob);
173
174 /* sha1 the data */
175 EVP_DigestInit(&md, evp_md);
176 EVP_DigestUpdate(&md, data, datalen);
177 EVP_DigestFinal(&md, digest, &dlen);
178
179 ret = DSA_do_verify(digest, dlen, sig, key->dsa);
180 memset(digest, 'd', sizeof(digest));
181
182 DSA_SIG_free(sig);
183
184 debug("ssh_dss_verify: signature %s",
185 ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
186 return ret;
187}
|