1 /* $OpenBSD: ssh-pkcs11-helper.c,v 1.17 2019/01/23 02:01:10 djm Exp $ */
3 * Copyright (c) 2010 Markus Friedl. All rights reserved.
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.
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.
20 #include <sys/types.h>
21 #ifdef HAVE_SYS_TIME_H
22 # include <sys/time.h>
25 #include "openbsd-compat/sys-queue.h"
39 #include "ssh-pkcs11.h"
44 /* borrows code from sftp-server and ssh-agent */
46 struct pkcs11_keyinfo {
49 TAILQ_ENTRY(pkcs11_keyinfo) next;
52 TAILQ_HEAD(, pkcs11_keyinfo) pkcs11_keylist;
54 #define MAX_MSG_LENGTH 10240 /*XXX*/
56 /* input and output queue */
57 struct sshbuf *iqueue;
58 struct sshbuf *oqueue;
61 add_key(struct sshkey *k, char *name)
63 struct pkcs11_keyinfo *ki;
65 ki = xcalloc(1, sizeof(*ki));
66 ki->providername = xstrdup(name);
68 TAILQ_INSERT_TAIL(&pkcs11_keylist, ki, next);
72 del_keys_by_name(char *name)
74 struct pkcs11_keyinfo *ki, *nxt;
76 for (ki = TAILQ_FIRST(&pkcs11_keylist); ki; ki = nxt) {
77 nxt = TAILQ_NEXT(ki, next);
78 if (!strcmp(ki->providername, name)) {
79 TAILQ_REMOVE(&pkcs11_keylist, ki, next);
80 free(ki->providername);
87 /* lookup matching 'private' key */
88 static struct sshkey *
89 lookup_key(struct sshkey *k)
91 struct pkcs11_keyinfo *ki;
93 TAILQ_FOREACH(ki, &pkcs11_keylist, next) {
94 debug("check %p %s", ki, ki->providername);
95 if (sshkey_equal(k, ki->key))
102 send_msg(struct sshbuf *m)
106 if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
107 fatal("%s: buffer error: %s", __func__, ssh_err(r));
114 struct sshkey **keys = NULL;
120 if ((msg = sshbuf_new()) == NULL)
121 fatal("%s: sshbuf_new failed", __func__);
122 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
123 (r = sshbuf_get_cstring(iqueue, &pin, NULL)) != 0)
124 fatal("%s: buffer error: %s", __func__, ssh_err(r));
125 if ((nkeys = pkcs11_add_provider(name, pin, &keys)) > 0) {
126 if ((r = sshbuf_put_u8(msg,
127 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
128 (r = sshbuf_put_u32(msg, nkeys)) != 0)
129 fatal("%s: buffer error: %s", __func__, ssh_err(r));
130 for (i = 0; i < nkeys; i++) {
131 if ((r = sshkey_to_blob(keys[i], &blob, &blen)) != 0) {
132 debug("%s: sshkey_to_blob: %s",
133 __func__, ssh_err(r));
136 if ((r = sshbuf_put_string(msg, blob, blen)) != 0 ||
137 (r = sshbuf_put_cstring(msg, name)) != 0)
138 fatal("%s: buffer error: %s",
139 __func__, ssh_err(r));
141 add_key(keys[i], name);
144 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
145 fatal("%s: buffer error: %s", __func__, ssh_err(r));
146 if ((r = sshbuf_put_u32(msg, -nkeys)) != 0)
147 fatal("%s: buffer error: %s", __func__, ssh_err(r));
163 if ((msg = sshbuf_new()) == NULL)
164 fatal("%s: sshbuf_new failed", __func__);
165 if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
166 (r = sshbuf_get_cstring(iqueue, &pin, NULL)) != 0)
167 fatal("%s: buffer error: %s", __func__, ssh_err(r));
168 del_keys_by_name(name);
169 if ((r = sshbuf_put_u8(msg, pkcs11_del_provider(name) == 0 ?
170 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
171 fatal("%s: buffer error: %s", __func__, ssh_err(r));
181 u_char *blob, *data, *signature = NULL;
182 size_t blen, dlen, slen = 0;
184 struct sshkey *key, *found;
187 /* XXX support SHA2 signature flags */
188 if ((r = sshbuf_get_string(iqueue, &blob, &blen)) != 0 ||
189 (r = sshbuf_get_string(iqueue, &data, &dlen)) != 0 ||
190 (r = sshbuf_get_u32(iqueue, NULL)) != 0)
191 fatal("%s: buffer error: %s", __func__, ssh_err(r));
193 if ((r = sshkey_from_blob(blob, blen, &key)) != 0)
194 error("%s: sshkey_from_blob: %s", __func__, ssh_err(r));
196 if ((found = lookup_key(key)) != NULL) {
201 if (key->type == KEY_RSA) {
202 slen = RSA_size(key->rsa);
203 signature = xmalloc(slen);
204 ret = RSA_private_encrypt(dlen, data, signature,
205 found->rsa, RSA_PKCS1_PADDING);
210 } else if (key->type == KEY_ECDSA) {
211 xslen = ECDSA_size(key->ecdsa);
212 signature = xmalloc(xslen);
213 /* "The parameter type is ignored." */
214 ret = ECDSA_sign(-1, data, dlen, signature,
215 &xslen, found->ecdsa);
219 error("%s: ECDSA_sign"
220 " returns %d", __func__, ret);
223 error("%s: don't know how to sign with key "
224 "type %d", __func__, (int)key->type);
225 #endif /* WITH_OPENSSL */
229 if ((msg = sshbuf_new()) == NULL)
230 fatal("%s: sshbuf_new failed", __func__);
232 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
233 (r = sshbuf_put_string(msg, signature, slen)) != 0)
234 fatal("%s: buffer error: %s", __func__, ssh_err(r));
236 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_FAILURE)) != 0)
237 fatal("%s: buffer error: %s", __func__, ssh_err(r));
256 buf_len = sshbuf_len(iqueue);
258 return; /* Incomplete message. */
259 cp = sshbuf_ptr(iqueue);
260 msg_len = get_u32(cp);
261 if (msg_len > MAX_MSG_LENGTH) {
262 error("bad message len %d", msg_len);
265 if (buf_len < msg_len + 4)
267 if ((r = sshbuf_consume(iqueue, 4)) != 0 ||
268 (r = sshbuf_get_u8(iqueue, &type)) != 0)
269 fatal("%s: buffer error: %s", __func__, ssh_err(r));
272 case SSH_AGENTC_ADD_SMARTCARD_KEY:
273 debug("process_add");
276 case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
277 debug("process_del");
280 case SSH2_AGENTC_SIGN_REQUEST:
281 debug("process_sign");
285 error("Unknown message %d", type);
288 /* discard the remaining bytes from the current packet */
289 if (buf_len < sshbuf_len(iqueue)) {
290 error("iqueue grew unexpectedly");
293 consumed = buf_len - sshbuf_len(iqueue);
294 if (msg_len < consumed) {
295 error("msg_len %d < consumed %d", msg_len, consumed);
298 if (msg_len > consumed) {
299 if ((r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
300 fatal("%s: buffer error: %s", __func__, ssh_err(r));
313 main(int argc, char **argv)
315 int r, ch, in, out, max, log_stderr = 0;
317 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
318 LogLevel log_level = SYSLOG_LEVEL_ERROR;
320 extern char *__progname;
321 struct pollfd pfd[2];
323 ssh_malloc_init(); /* must be called before any mallocs */
324 __progname = ssh_get_progname(argv[0]);
326 TAILQ_INIT(&pkcs11_keylist);
328 log_init(__progname, log_level, log_facility, log_stderr);
330 while ((ch = getopt(argc, argv, "v")) != -1) {
334 if (log_level == SYSLOG_LEVEL_ERROR)
335 log_level = SYSLOG_LEVEL_DEBUG1;
336 else if (log_level < SYSLOG_LEVEL_DEBUG3)
340 fprintf(stderr, "usage: %s [-v]\n", __progname);
345 log_init(__progname, log_level, log_facility, log_stderr);
358 if ((iqueue = sshbuf_new()) == NULL)
359 fatal("%s: sshbuf_new failed", __func__);
360 if ((oqueue = sshbuf_new()) == NULL)
361 fatal("%s: sshbuf_new failed", __func__);
364 memset(pfd, 0, sizeof(pfd));
369 * Ensure that we can read a full buffer and handle
370 * the worst-case length packet it can generate,
371 * otherwise apply backpressure by stopping reads.
373 if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
374 (r = sshbuf_check_reserve(oqueue, MAX_MSG_LENGTH)) == 0)
375 pfd[0].events = POLLIN;
376 else if (r != SSH_ERR_NO_BUFFER_SPACE)
377 fatal("%s: buffer error: %s", __func__, ssh_err(r));
379 if (sshbuf_len(oqueue) > 0)
380 pfd[1].events = POLLOUT;
382 if ((r = poll(pfd, 2, -1 /* INFTIM */)) <= 0) {
383 if (r == 0 || errno == EINTR)
385 fatal("poll: %s", strerror(errno));
388 /* copy stdin to iqueue */
389 if ((pfd[0].revents & (POLLIN|POLLERR)) != 0) {
390 len = read(in, buf, sizeof buf);
394 } else if (len < 0) {
395 error("read: %s", strerror(errno));
397 } else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
398 fatal("%s: buffer error: %s",
399 __func__, ssh_err(r));
402 /* send oqueue to stdout */
403 if ((pfd[1].revents & (POLLOUT|POLLHUP)) != 0) {
404 len = write(out, sshbuf_ptr(oqueue),
407 error("write: %s", strerror(errno));
409 } else if ((r = sshbuf_consume(oqueue, len)) != 0) {
410 fatal("%s: buffer error: %s",
411 __func__, ssh_err(r));
416 * Process requests from client if we can fit the results
417 * into the output buffer, otherwise stop processing input
418 * and let the output queue drain.
420 if ((r = sshbuf_check_reserve(oqueue, MAX_MSG_LENGTH)) == 0)
422 else if (r != SSH_ERR_NO_BUFFER_SPACE)
423 fatal("%s: buffer error: %s", __func__, ssh_err(r));
426 #else /* ENABLE_PKCS11 */
428 main(int argc, char **argv)
430 extern char *__progname;
432 __progname = ssh_get_progname(argv[0]);
433 log_init(__progname, SYSLOG_LEVEL_ERROR, SYSLOG_FACILITY_AUTH, 0);
434 fatal("PKCS#11 support disabled at compile time");
436 #endif /* ENABLE_PKCS11 */