blob: 8c74864aa3629fdb42d4f928fbfd04eda5609325 [file] [log] [blame]
Damien Miller86687062014-07-02 15:28:02 +10001/* $OpenBSD: ssh-pkcs11-client.c,v 1.5 2014/06/24 01:13:21 djm Exp $ */
Damien Miller7ea845e2010-02-12 09:21:02 +11002/*
3 * Copyright (c) 2010 Markus Friedl. All rights reserved.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
Damien Miller8ad0fbd2010-02-12 09:49:06 +110018#include "includes.h"
19
Damien Millerdfa41562010-02-12 10:06:28 +110020#ifdef ENABLE_PKCS11
21
Damien Miller7ea845e2010-02-12 09:21:02 +110022#include <sys/types.h>
Damien Miller8ad0fbd2010-02-12 09:49:06 +110023#ifdef HAVE_SYS_TIME_H
24# include <sys/time.h>
25#endif
Damien Miller7ea845e2010-02-12 09:21:02 +110026#include <sys/socket.h>
27
28#include <stdarg.h>
29#include <string.h>
30#include <unistd.h>
31#include <errno.h>
32
Damien Miller86687062014-07-02 15:28:02 +100033#include <openssl/rsa.h>
34
Damien Miller7ea845e2010-02-12 09:21:02 +110035#include "pathnames.h"
36#include "xmalloc.h"
37#include "buffer.h"
38#include "log.h"
39#include "misc.h"
40#include "key.h"
41#include "authfd.h"
42#include "atomicio.h"
43#include "ssh-pkcs11.h"
44
45/* borrows code from sftp-server and ssh-agent */
46
47int fd = -1;
48pid_t pid = -1;
49
50static void
51send_msg(Buffer *m)
52{
53 u_char buf[4];
54 int mlen = buffer_len(m);
55
56 put_u32(buf, mlen);
57 if (atomicio(vwrite, fd, buf, 4) != 4 ||
58 atomicio(vwrite, fd, buffer_ptr(m),
59 buffer_len(m)) != buffer_len(m))
60 error("write to helper failed");
61 buffer_consume(m, mlen);
62}
63
64static int
65recv_msg(Buffer *m)
66{
67 u_int l, len;
68 u_char buf[1024];
69
70 if ((len = atomicio(read, fd, buf, 4)) != 4) {
71 error("read from helper failed: %u", len);
72 return (0); /* XXX */
73 }
74 len = get_u32(buf);
75 if (len > 256 * 1024)
76 fatal("response too long: %u", len);
77 /* read len bytes into m */
78 buffer_clear(m);
79 while (len > 0) {
80 l = len;
81 if (l > sizeof(buf))
82 l = sizeof(buf);
83 if (atomicio(read, fd, buf, l) != l) {
84 error("response from helper failed.");
85 return (0); /* XXX */
86 }
87 buffer_append(m, buf, l);
88 len -= l;
89 }
90 return (buffer_get_char(m));
91}
92
93int
94pkcs11_init(int interactive)
95{
96 return (0);
97}
98
99void
100pkcs11_terminate(void)
101{
102 close(fd);
103}
104
105static int
106pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
107 int padding)
108{
109 Key key;
110 u_char *blob, *signature = NULL;
111 u_int blen, slen = 0;
112 int ret = -1;
113 Buffer msg;
114
115 if (padding != RSA_PKCS1_PADDING)
116 return (-1);
117 key.type = KEY_RSA;
118 key.rsa = rsa;
119 if (key_to_blob(&key, &blob, &blen) == 0)
120 return -1;
121 buffer_init(&msg);
122 buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
123 buffer_put_string(&msg, blob, blen);
124 buffer_put_string(&msg, from, flen);
125 buffer_put_int(&msg, 0);
Darren Tuckera627d422013-06-02 07:31:17 +1000126 free(blob);
Damien Miller7ea845e2010-02-12 09:21:02 +1100127 send_msg(&msg);
Damien Millerfb12c6d2012-02-11 08:17:52 +1100128 buffer_clear(&msg);
Damien Miller7ea845e2010-02-12 09:21:02 +1100129
130 if (recv_msg(&msg) == SSH2_AGENT_SIGN_RESPONSE) {
131 signature = buffer_get_string(&msg, &slen);
132 if (slen <= (u_int)RSA_size(rsa)) {
133 memcpy(to, signature, slen);
134 ret = slen;
135 }
Darren Tuckera627d422013-06-02 07:31:17 +1000136 free(signature);
Damien Miller7ea845e2010-02-12 09:21:02 +1100137 }
Damien Millerfb12c6d2012-02-11 08:17:52 +1100138 buffer_free(&msg);
Damien Miller7ea845e2010-02-12 09:21:02 +1100139 return (ret);
140}
141
142/* redirect the private key encrypt operation to the ssh-pkcs11-helper */
143static int
144wrap_key(RSA *rsa)
145{
146 static RSA_METHOD helper_rsa;
147
148 memcpy(&helper_rsa, RSA_get_default_method(), sizeof(helper_rsa));
149 helper_rsa.name = "ssh-pkcs11-helper";
150 helper_rsa.rsa_priv_enc = pkcs11_rsa_private_encrypt;
151 RSA_set_method(rsa, &helper_rsa);
152 return (0);
153}
154
155static int
156pkcs11_start_helper(void)
157{
158 int pair[2];
159
160 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
161 error("socketpair: %s", strerror(errno));
162 return (-1);
163 }
164 if ((pid = fork()) == -1) {
165 error("fork: %s", strerror(errno));
166 return (-1);
167 } else if (pid == 0) {
168 if ((dup2(pair[1], STDIN_FILENO) == -1) ||
169 (dup2(pair[1], STDOUT_FILENO) == -1)) {
170 fprintf(stderr, "dup2: %s\n", strerror(errno));
171 _exit(1);
172 }
173 close(pair[0]);
174 close(pair[1]);
175 execlp(_PATH_SSH_PKCS11_HELPER, _PATH_SSH_PKCS11_HELPER,
176 (char *) 0);
177 fprintf(stderr, "exec: %s: %s\n", _PATH_SSH_PKCS11_HELPER,
178 strerror(errno));
179 _exit(1);
180 }
181 close(pair[1]);
182 fd = pair[0];
183 return (0);
184}
185
186int
187pkcs11_add_provider(char *name, char *pin, Key ***keysp)
188{
189 Key *k;
190 int i, nkeys;
191 u_char *blob;
192 u_int blen;
193 Buffer msg;
194
195 if (fd < 0 && pkcs11_start_helper() < 0)
196 return (-1);
197
198 buffer_init(&msg);
199 buffer_put_char(&msg, SSH_AGENTC_ADD_SMARTCARD_KEY);
200 buffer_put_cstring(&msg, name);
201 buffer_put_cstring(&msg, pin);
202 send_msg(&msg);
203 buffer_clear(&msg);
204
205 if (recv_msg(&msg) == SSH2_AGENT_IDENTITIES_ANSWER) {
206 nkeys = buffer_get_int(&msg);
207 *keysp = xcalloc(nkeys, sizeof(Key *));
208 for (i = 0; i < nkeys; i++) {
209 blob = buffer_get_string(&msg, &blen);
Darren Tuckera627d422013-06-02 07:31:17 +1000210 free(buffer_get_string(&msg, NULL));
Damien Miller7ea845e2010-02-12 09:21:02 +1100211 k = key_from_blob(blob, blen);
212 wrap_key(k->rsa);
213 (*keysp)[i] = k;
Darren Tuckera627d422013-06-02 07:31:17 +1000214 free(blob);
Damien Miller7ea845e2010-02-12 09:21:02 +1100215 }
216 } else {
217 nkeys = -1;
218 }
219 buffer_free(&msg);
220 return (nkeys);
221}
222
223int
224pkcs11_del_provider(char *name)
225{
226 int ret = -1;
227 Buffer msg;
228
229 buffer_init(&msg);
230 buffer_put_char(&msg, SSH_AGENTC_REMOVE_SMARTCARD_KEY);
231 buffer_put_cstring(&msg, name);
232 buffer_put_cstring(&msg, "");
233 send_msg(&msg);
234 buffer_clear(&msg);
235
236 if (recv_msg(&msg) == SSH_AGENT_SUCCESS)
237 ret = 0;
238 buffer_free(&msg);
239 return (ret);
240}
Damien Millerdfa41562010-02-12 10:06:28 +1100241
242#endif /* ENABLE_PKCS11 */