diff options
Diffstat (limited to 'ssh-rsa.c')
-rw-r--r-- | ssh-rsa.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/ssh-rsa.c b/ssh-rsa.c new file mode 100644 index 000000000..cc31154d9 --- /dev/null +++ b/ssh-rsa.c | |||
@@ -0,0 +1,163 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | ||
3 | * | ||
4 | * Redistribution and use in source and binary forms, with or without | ||
5 | * modification, are permitted provided that the following conditions | ||
6 | * are met: | ||
7 | * 1. Redistributions of source code must retain the above copyright | ||
8 | * notice, this list of conditions and the following disclaimer. | ||
9 | * 2. Redistributions in binary form must reproduce the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer in the | ||
11 | * documentation and/or other materials provided with the distribution. | ||
12 | * | ||
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | ||
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | ||
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | ||
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | ||
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | ||
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | ||
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | ||
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
23 | */ | ||
24 | |||
25 | #include "includes.h" | ||
26 | RCSID("$OpenBSD: ssh-rsa.c,v 1.1 2000/11/12 19:50:38 markus Exp $"); | ||
27 | |||
28 | #include "ssh.h" | ||
29 | #include "xmalloc.h" | ||
30 | #include "buffer.h" | ||
31 | #include "bufaux.h" | ||
32 | |||
33 | #include <openssl/evp.h> | ||
34 | #include <openssl/dsa.h> | ||
35 | #include <openssl/rsa.h> | ||
36 | #include <openssl/err.h> | ||
37 | |||
38 | #include "key.h" | ||
39 | |||
40 | #define INTBLOB_LEN 20 | ||
41 | #define SIGBLOB_LEN (2*INTBLOB_LEN) | ||
42 | |||
43 | /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ | ||
44 | int | ||
45 | ssh_rsa_sign( | ||
46 | Key *key, | ||
47 | unsigned char **sigp, int *lenp, | ||
48 | unsigned char *data, int datalen) | ||
49 | { | ||
50 | EVP_MD *evp_md = EVP_sha1(); | ||
51 | EVP_MD_CTX md; | ||
52 | unsigned char *digest, *sig, *ret; | ||
53 | unsigned int slen, dlen, len; | ||
54 | int ok; | ||
55 | Buffer b; | ||
56 | |||
57 | if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) { | ||
58 | error("ssh_rsa_sign: no RSA key"); | ||
59 | return -1; | ||
60 | } | ||
61 | slen = RSA_size(key->rsa); | ||
62 | sig = xmalloc(slen); | ||
63 | |||
64 | dlen = evp_md->md_size; | ||
65 | digest = xmalloc(dlen); | ||
66 | EVP_DigestInit(&md, evp_md); | ||
67 | EVP_DigestUpdate(&md, data, datalen); | ||
68 | EVP_DigestFinal(&md, digest, NULL); | ||
69 | |||
70 | ok = RSA_sign(NID_sha1, digest, dlen, sig, &len, key->rsa); | ||
71 | memset(digest, 'd', dlen); | ||
72 | xfree(digest); | ||
73 | |||
74 | if (ok != 1) { | ||
75 | int ecode = ERR_get_error(); | ||
76 | error("ssh_rsa_sign: RSA_sign failed: %s", ERR_error_string(ecode, NULL)); | ||
77 | xfree(sig); | ||
78 | return -1; | ||
79 | } | ||
80 | if (len < slen) { | ||
81 | int diff = slen - len; | ||
82 | debug("slen %d > len %d", slen, len); | ||
83 | memmove(sig + diff, sig, len); | ||
84 | memset(sig, 0, diff); | ||
85 | } else if (len > slen) { | ||
86 | error("ssh_rsa_sign: slen %d slen2 %d", slen, len); | ||
87 | xfree(sig); | ||
88 | return -1; | ||
89 | } | ||
90 | /* encode signature */ | ||
91 | buffer_init(&b); | ||
92 | buffer_put_cstring(&b, "ssh-rsa"); | ||
93 | buffer_put_string(&b, sig, slen); | ||
94 | len = buffer_len(&b); | ||
95 | ret = xmalloc(len); | ||
96 | memcpy(ret, buffer_ptr(&b), len); | ||
97 | buffer_free(&b); | ||
98 | memset(sig, 's', slen); | ||
99 | xfree(sig); | ||
100 | |||
101 | if (lenp != NULL) | ||
102 | *lenp = len; | ||
103 | if (sigp != NULL) | ||
104 | *sigp = ret; | ||
105 | debug2("ssh_rsa_sign: done"); | ||
106 | return 0; | ||
107 | } | ||
108 | |||
109 | int | ||
110 | ssh_rsa_verify( | ||
111 | Key *key, | ||
112 | unsigned char *signature, int signaturelen, | ||
113 | unsigned char *data, int datalen) | ||
114 | { | ||
115 | Buffer b; | ||
116 | EVP_MD *evp_md = EVP_sha1(); | ||
117 | EVP_MD_CTX md; | ||
118 | char *ktype; | ||
119 | unsigned char *sigblob, *digest; | ||
120 | unsigned int len, dlen; | ||
121 | int rlen; | ||
122 | int ret; | ||
123 | |||
124 | if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) { | ||
125 | error("ssh_rsa_verify: no RSA key"); | ||
126 | return -1; | ||
127 | } | ||
128 | buffer_init(&b); | ||
129 | buffer_append(&b, (char *) signature, signaturelen); | ||
130 | ktype = buffer_get_string(&b, NULL); | ||
131 | if (strcmp("ssh-rsa", ktype) != 0) { | ||
132 | error("ssh_rsa_verify: cannot handle type %s", ktype); | ||
133 | buffer_free(&b); | ||
134 | xfree(ktype); | ||
135 | return -1; | ||
136 | } | ||
137 | xfree(ktype); | ||
138 | sigblob = (unsigned char *)buffer_get_string(&b, &len); | ||
139 | rlen = buffer_len(&b); | ||
140 | buffer_free(&b); | ||
141 | if(rlen != 0) { | ||
142 | error("ssh_rsa_verify: remaining bytes in signature %d", rlen); | ||
143 | return -1; | ||
144 | } | ||
145 | |||
146 | dlen = evp_md->md_size; | ||
147 | digest = xmalloc(dlen); | ||
148 | EVP_DigestInit(&md, evp_md); | ||
149 | EVP_DigestUpdate(&md, data, datalen); | ||
150 | EVP_DigestFinal(&md, digest, NULL); | ||
151 | |||
152 | ret = RSA_verify(NID_sha1, digest, dlen, sigblob, len, key->rsa); | ||
153 | memset(digest, 'd', dlen); | ||
154 | xfree(digest); | ||
155 | memset(sigblob, 's', len); | ||
156 | xfree(sigblob); | ||
157 | if (ret == 0) { | ||
158 | int ecode = ERR_get_error(); | ||
159 | error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL)); | ||
160 | } | ||
161 | debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : ""); | ||
162 | return ret; | ||
163 | } | ||