1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/* $OpenBSD: ssh-pkcs11-client.c,v 1.5 2014/06/24 01:13:21 djm Exp $ */
/*
* Copyright (c) 2010 Markus Friedl. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <openssl/rsa.h>
#include "pathnames.h"
#include "xmalloc.h"
#include "buffer.h"
#include "log.h"
#include "misc.h"
#include "key.h"
#include "authfd.h"
#include "atomicio.h"
#include "ssh-pkcs11.h"
/* borrows code from sftp-server and ssh-agent */
int fd = -1;
pid_t pid = -1;
static void
send_msg(Buffer *m)
{
u_char buf[4];
int mlen = buffer_len(m);
put_u32(buf, mlen);
if (atomicio(vwrite, fd, buf, 4) != 4 ||
atomicio(vwrite, fd, buffer_ptr(m),
buffer_len(m)) != buffer_len(m))
error("write to helper failed");
buffer_consume(m, mlen);
}
static int
recv_msg(Buffer *m)
{
u_int l, len;
u_char buf[1024];
if ((len = atomicio(read, fd, buf, 4)) != 4) {
error("read from helper failed: %u", len);
return (0); /* XXX */
}
len = get_u32(buf);
if (len > 256 * 1024)
fatal("response too long: %u", len);
/* read len bytes into m */
buffer_clear(m);
while (len > 0) {
l = len;
if (l > sizeof(buf))
l = sizeof(buf);
if (atomicio(read, fd, buf, l) != l) {
error("response from helper failed.");
return (0); /* XXX */
}
buffer_append(m, buf, l);
len -= l;
}
return (buffer_get_char(m));
}
int
pkcs11_init(int interactive)
{
return (0);
}
void
pkcs11_terminate(void)
{
close(fd);
}
static int
pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
int padding)
{
Key key;
u_char *blob, *signature = NULL;
u_int blen, slen = 0;
int ret = -1;
Buffer msg;
if (padding != RSA_PKCS1_PADDING)
return (-1);
key.type = KEY_RSA;
key.rsa = rsa;
if (key_to_blob(&key, &blob, &blen) == 0)
return -1;
buffer_init(&msg);
buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
buffer_put_string(&msg, blob, blen);
buffer_put_string(&msg, from, flen);
buffer_put_int(&msg, 0);
free(blob);
send_msg(&msg);
buffer_clear(&msg);
if (recv_msg(&msg) == SSH2_AGENT_SIGN_RESPONSE) {
signature = buffer_get_string(&msg, &slen);
if (slen <= (u_int)RSA_size(rsa)) {
memcpy(to, signature, slen);
ret = slen;
}
free(signature);
}
buffer_free(&msg);
return (ret);
}
/* redirect the private key encrypt operation to the ssh-pkcs11-helper */
static int
wrap_key(RSA *rsa)
{
static RSA_METHOD helper_rsa;
memcpy(&helper_rsa, RSA_get_default_method(), sizeof(helper_rsa));
helper_rsa.name = "ssh-pkcs11-helper";
helper_rsa.rsa_priv_enc = pkcs11_rsa_private_encrypt;
RSA_set_method(rsa, &helper_rsa);
return (0);
}
static int
pkcs11_start_helper(void)
{
int pair[2];
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
error("socketpair: %s", strerror(errno));
return (-1);
}
if ((pid = fork()) == -1) {
error("fork: %s", strerror(errno));
return (-1);
} else if (pid == 0) {
if ((dup2(pair[1], STDIN_FILENO) == -1) ||
(dup2(pair[1], STDOUT_FILENO) == -1)) {
fprintf(stderr, "dup2: %s\n", strerror(errno));
_exit(1);
}
close(pair[0]);
close(pair[1]);
execlp(_PATH_SSH_PKCS11_HELPER, _PATH_SSH_PKCS11_HELPER,
(char *) 0);
fprintf(stderr, "exec: %s: %s\n", _PATH_SSH_PKCS11_HELPER,
strerror(errno));
_exit(1);
}
close(pair[1]);
fd = pair[0];
return (0);
}
int
pkcs11_add_provider(char *name, char *pin, Key ***keysp)
{
Key *k;
int i, nkeys;
u_char *blob;
u_int blen;
Buffer msg;
if (fd < 0 && pkcs11_start_helper() < 0)
return (-1);
buffer_init(&msg);
buffer_put_char(&msg, SSH_AGENTC_ADD_SMARTCARD_KEY);
buffer_put_cstring(&msg, name);
buffer_put_cstring(&msg, pin);
send_msg(&msg);
buffer_clear(&msg);
if (recv_msg(&msg) == SSH2_AGENT_IDENTITIES_ANSWER) {
nkeys = buffer_get_int(&msg);
*keysp = xcalloc(nkeys, sizeof(Key *));
for (i = 0; i < nkeys; i++) {
blob = buffer_get_string(&msg, &blen);
free(buffer_get_string(&msg, NULL));
k = key_from_blob(blob, blen);
wrap_key(k->rsa);
(*keysp)[i] = k;
free(blob);
}
} else {
nkeys = -1;
}
buffer_free(&msg);
return (nkeys);
}
int
pkcs11_del_provider(char *name)
{
int ret = -1;
Buffer msg;
buffer_init(&msg);
buffer_put_char(&msg, SSH_AGENTC_REMOVE_SMARTCARD_KEY);
buffer_put_cstring(&msg, name);
buffer_put_cstring(&msg, "");
send_msg(&msg);
buffer_clear(&msg);
if (recv_msg(&msg) == SSH_AGENT_SUCCESS)
ret = 0;
buffer_free(&msg);
return (ret);
}
|
