1 /* $OpenBSD: ssh-pkcs11-client.c,v 1.20 2024/08/15 00:51:51 djm Exp $ */
2 /*
3 * Copyright (c) 2010 Markus Friedl. All rights reserved.
4 * Copyright (c) 2014 Pedro Martelletto. All rights reserved.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20 #include <sys/time.h>
21 #include <sys/socket.h>
22
23 #include <stdarg.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <errno.h>
27 #include <limits.h>
28
29 #include <openssl/ecdsa.h>
30 #include <openssl/rsa.h>
31
32 #include "pathnames.h"
33 #include "xmalloc.h"
34 #include "sshbuf.h"
35 #include "log.h"
36 #include "misc.h"
37 #include "sshkey.h"
38 #include "authfd.h"
39 #include "atomicio.h"
40 #include "ssh-pkcs11.h"
41 #include "ssherr.h"
42
43 /* borrows code from sftp-server and ssh-agent */
44
45 /*
46 * Maintain a list of ssh-pkcs11-helper subprocesses. These may be looked up
47 * by provider path or their unique EC/RSA METHOD pointers.
48 */
49 struct helper {
50 char *path;
51 pid_t pid;
52 int fd;
53 RSA_METHOD *rsa_meth;
54 EC_KEY_METHOD *ec_meth;
55 int (*rsa_finish)(RSA *rsa);
56 void (*ec_finish)(EC_KEY *key);
57 size_t nrsa, nec; /* number of active keys of each type */
58 };
59 static struct helper **helpers;
60 static size_t nhelpers;
61
62 static struct helper *
helper_by_provider(const char * path)63 helper_by_provider(const char *path)
64 {
65 size_t i;
66
67 for (i = 0; i < nhelpers; i++) {
68 if (helpers[i] == NULL || helpers[i]->path == NULL ||
69 helpers[i]->fd == -1)
70 continue;
71 if (strcmp(helpers[i]->path, path) == 0)
72 return helpers[i];
73 }
74 return NULL;
75 }
76
77 static struct helper *
helper_by_rsa(const RSA * rsa)78 helper_by_rsa(const RSA *rsa)
79 {
80 size_t i;
81 const RSA_METHOD *meth;
82
83 if ((meth = RSA_get_method(rsa)) == NULL)
84 return NULL;
85 for (i = 0; i < nhelpers; i++) {
86 if (helpers[i] != NULL && helpers[i]->rsa_meth == meth)
87 return helpers[i];
88 }
89 return NULL;
90
91 }
92
93 static struct helper *
helper_by_ec(const EC_KEY * ec)94 helper_by_ec(const EC_KEY *ec)
95 {
96 size_t i;
97 const EC_KEY_METHOD *meth;
98
99 if ((meth = EC_KEY_get_method(ec)) == NULL)
100 return NULL;
101 for (i = 0; i < nhelpers; i++) {
102 if (helpers[i] != NULL && helpers[i]->ec_meth == meth)
103 return helpers[i];
104 }
105 return NULL;
106
107 }
108
109 static void
helper_free(struct helper * helper)110 helper_free(struct helper *helper)
111 {
112 size_t i;
113 int found = 0;
114
115 if (helper == NULL)
116 return;
117 if (helper->path == NULL || helper->ec_meth == NULL ||
118 helper->rsa_meth == NULL)
119 fatal_f("inconsistent helper");
120 debug3_f("free helper for provider %s", helper->path);
121 for (i = 0; i < nhelpers; i++) {
122 if (helpers[i] == helper) {
123 if (found)
124 fatal_f("helper recorded more than once");
125 found = 1;
126 }
127 else if (found)
128 helpers[i - 1] = helpers[i];
129 }
130 if (found) {
131 helpers = xrecallocarray(helpers, nhelpers,
132 nhelpers - 1, sizeof(*helpers));
133 nhelpers--;
134 }
135 free(helper->path);
136 EC_KEY_METHOD_free(helper->ec_meth);
137 RSA_meth_free(helper->rsa_meth);
138 free(helper);
139 }
140
141 static void
helper_terminate(struct helper * helper)142 helper_terminate(struct helper *helper)
143 {
144 if (helper == NULL) {
145 return;
146 } else if (helper->fd == -1) {
147 debug3_f("already terminated");
148 } else {
149 debug3_f("terminating helper for %s; "
150 "remaining %zu RSA %zu ECDSA",
151 helper->path, helper->nrsa, helper->nec);
152 close(helper->fd);
153 /* XXX waitpid() */
154 helper->fd = -1;
155 helper->pid = -1;
156 }
157 /*
158 * Don't delete the helper entry until there are no remaining keys
159 * that reference it. Otherwise, any signing operation would call
160 * a free'd METHOD pointer and that would be bad.
161 */
162 if (helper->nrsa == 0 && helper->nec == 0)
163 helper_free(helper);
164 }
165
166 static void
send_msg(int fd,struct sshbuf * m)167 send_msg(int fd, struct sshbuf *m)
168 {
169 u_char buf[4];
170 size_t mlen = sshbuf_len(m);
171 int r;
172
173 if (fd == -1)
174 return;
175 POKE_U32(buf, mlen);
176 if (atomicio(vwrite, fd, buf, 4) != 4 ||
177 atomicio(vwrite, fd, sshbuf_mutable_ptr(m),
178 sshbuf_len(m)) != sshbuf_len(m))
179 error("write to helper failed");
180 if ((r = sshbuf_consume(m, mlen)) != 0)
181 fatal_fr(r, "consume");
182 }
183
184 static int
recv_msg(int fd,struct sshbuf * m)185 recv_msg(int fd, struct sshbuf *m)
186 {
187 u_int l, len;
188 u_char c, buf[1024];
189 int r;
190
191 sshbuf_reset(m);
192 if (fd == -1)
193 return 0; /* XXX */
194 if ((len = atomicio(read, fd, buf, 4)) != 4) {
195 error("read from helper failed: %u", len);
196 return (0); /* XXX */
197 }
198 len = PEEK_U32(buf);
199 if (len > 256 * 1024)
200 fatal("response too long: %u", len);
201 /* read len bytes into m */
202 while (len > 0) {
203 l = len;
204 if (l > sizeof(buf))
205 l = sizeof(buf);
206 if (atomicio(read, fd, buf, l) != l) {
207 error("response from helper failed.");
208 return (0); /* XXX */
209 }
210 if ((r = sshbuf_put(m, buf, l)) != 0)
211 fatal_fr(r, "sshbuf_put");
212 len -= l;
213 }
214 if ((r = sshbuf_get_u8(m, &c)) != 0)
215 fatal_fr(r, "parse type");
216 return c;
217 }
218
219 int
pkcs11_init(int interactive)220 pkcs11_init(int interactive)
221 {
222 return 0;
223 }
224
225 void
pkcs11_terminate(void)226 pkcs11_terminate(void)
227 {
228 size_t i;
229
230 debug3_f("terminating %zu helpers", nhelpers);
231 for (i = 0; i < nhelpers; i++)
232 helper_terminate(helpers[i]);
233 }
234
235 static int
rsa_encrypt(int flen,const u_char * from,u_char * to,RSA * rsa,int padding)236 rsa_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa, int padding)
237 {
238 struct sshkey *key = NULL;
239 struct sshbuf *msg = NULL;
240 u_char *blob = NULL, *signature = NULL;
241 size_t blen, slen = 0;
242 int r, ret = -1;
243 struct helper *helper;
244
245 if ((helper = helper_by_rsa(rsa)) == NULL || helper->fd == -1)
246 fatal_f("no helper for PKCS11 key");
247 debug3_f("signing with PKCS11 provider %s", helper->path);
248 if (padding != RSA_PKCS1_PADDING)
249 goto fail;
250 if ((key = sshkey_new(KEY_UNSPEC)) == NULL) {
251 error_f("sshkey_new failed");
252 goto fail;
253 }
254 if ((key->pkey = EVP_PKEY_new()) == NULL ||
255 EVP_PKEY_set1_RSA(key->pkey, rsa) != 1) {
256 error_f("pkey setup failed");
257 goto fail;
258 }
259
260 key->type = KEY_RSA;
261 if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) {
262 error_fr(r, "encode key");
263 goto fail;
264 }
265 if ((msg = sshbuf_new()) == NULL)
266 fatal_f("sshbuf_new failed");
267 if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
268 (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
269 (r = sshbuf_put_string(msg, from, flen)) != 0 ||
270 (r = sshbuf_put_u32(msg, 0)) != 0)
271 fatal_fr(r, "compose");
272 send_msg(helper->fd, msg);
273 sshbuf_reset(msg);
274
275 if (recv_msg(helper->fd, msg) == SSH2_AGENT_SIGN_RESPONSE) {
276 if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0)
277 fatal_fr(r, "parse");
278 if (slen <= (size_t)RSA_size(rsa)) {
279 memcpy(to, signature, slen);
280 ret = slen;
281 }
282 free(signature);
283 }
284 fail:
285 free(blob);
286 sshkey_free(key);
287 sshbuf_free(msg);
288 return (ret);
289 }
290
291 static int
rsa_finish(RSA * rsa)292 rsa_finish(RSA *rsa)
293 {
294 struct helper *helper;
295
296 if ((helper = helper_by_rsa(rsa)) == NULL)
297 fatal_f("no helper for PKCS11 key");
298 debug3_f("free PKCS11 RSA key for provider %s", helper->path);
299 if (helper->rsa_finish != NULL)
300 helper->rsa_finish(rsa);
301 if (helper->nrsa == 0)
302 fatal_f("RSA refcount error");
303 helper->nrsa--;
304 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA",
305 helper->path, helper->nrsa, helper->nec);
306 if (helper->nrsa == 0 && helper->nec == 0)
307 helper_terminate(helper);
308 return 1;
309 }
310
311 static ECDSA_SIG *
ecdsa_do_sign(const unsigned char * dgst,int dgst_len,const BIGNUM * inv,const BIGNUM * rp,EC_KEY * ec)312 ecdsa_do_sign(const unsigned char *dgst, int dgst_len, const BIGNUM *inv,
313 const BIGNUM *rp, EC_KEY *ec)
314 {
315 struct sshkey *key = NULL;
316 struct sshbuf *msg = NULL;
317 ECDSA_SIG *ret = NULL;
318 const u_char *cp;
319 u_char *blob = NULL, *signature = NULL;
320 size_t blen, slen = 0;
321 int r, nid;
322 struct helper *helper;
323
324 if ((helper = helper_by_ec(ec)) == NULL || helper->fd == -1)
325 fatal_f("no helper for PKCS11 key");
326 debug3_f("signing with PKCS11 provider %s", helper->path);
327
328 if ((key = sshkey_new(KEY_UNSPEC)) == NULL) {
329 error_f("sshkey_new failed");
330 goto fail;
331 }
332 if ((key->pkey = EVP_PKEY_new()) == NULL ||
333 EVP_PKEY_set1_EC_KEY(key->pkey, ec) != 1) {
334 error("pkey setup failed");
335 goto fail;
336 }
337 if ((nid = sshkey_ecdsa_pkey_to_nid(key->pkey)) < 0) {
338 error("couldn't get curve nid");
339 goto fail;
340 }
341 key->ecdsa_nid = nid;
342 key->type = KEY_ECDSA;
343
344 if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) {
345 error_fr(r, "encode key");
346 goto fail;
347 }
348 if ((msg = sshbuf_new()) == NULL)
349 fatal_f("sshbuf_new failed");
350 if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
351 (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
352 (r = sshbuf_put_string(msg, dgst, dgst_len)) != 0 ||
353 (r = sshbuf_put_u32(msg, 0)) != 0)
354 fatal_fr(r, "compose");
355 send_msg(helper->fd, msg);
356 sshbuf_reset(msg);
357
358 if (recv_msg(helper->fd, msg) == SSH2_AGENT_SIGN_RESPONSE) {
359 if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0)
360 fatal_fr(r, "parse");
361 cp = signature;
362 ret = d2i_ECDSA_SIG(NULL, &cp, slen);
363 free(signature);
364 }
365
366 fail:
367 free(blob);
368 sshkey_free(key);
369 sshbuf_free(msg);
370 return (ret);
371 }
372
373 static void
ecdsa_do_finish(EC_KEY * ec)374 ecdsa_do_finish(EC_KEY *ec)
375 {
376 struct helper *helper;
377
378 if ((helper = helper_by_ec(ec)) == NULL)
379 fatal_f("no helper for PKCS11 key");
380 debug3_f("free PKCS11 ECDSA key for provider %s", helper->path);
381 if (helper->ec_finish != NULL)
382 helper->ec_finish(ec);
383 if (helper->nec == 0)
384 fatal_f("ECDSA refcount error");
385 helper->nec--;
386 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA",
387 helper->path, helper->nrsa, helper->nec);
388 if (helper->nrsa == 0 && helper->nec == 0)
389 helper_terminate(helper);
390 }
391
392 /* redirect private key crypto operations to the ssh-pkcs11-helper */
393 static void
wrap_key(struct helper * helper,struct sshkey * k)394 wrap_key(struct helper *helper, struct sshkey *k)
395 {
396 RSA *rsa = NULL;
397 EC_KEY *ecdsa = NULL;
398
399 debug3_f("wrap %s for provider %s", sshkey_type(k), helper->path);
400 if (k->type == KEY_RSA) {
401 if ((rsa = EVP_PKEY_get1_RSA(k->pkey)) == NULL)
402 fatal_f("no RSA key");
403 if (RSA_set_method(rsa, helper->rsa_meth) != 1)
404 fatal_f("RSA_set_method failed");
405 if (helper->nrsa++ >= INT_MAX)
406 fatal_f("RSA refcount error");
407 if (EVP_PKEY_set1_RSA(k->pkey, rsa) != 1)
408 fatal_f("EVP_PKEY_set1_RSA failed");
409 RSA_free(rsa);
410 } else if (k->type == KEY_ECDSA) {
411 if ((ecdsa = EVP_PKEY_get1_EC_KEY(k->pkey)) == NULL)
412 fatal_f("no ECDSA key");
413 if (EC_KEY_set_method(ecdsa, helper->ec_meth) != 1)
414 fatal_f("EC_KEY_set_method failed");
415 if (helper->nec++ >= INT_MAX)
416 fatal_f("EC refcount error");
417 if (EVP_PKEY_set1_EC_KEY(k->pkey, ecdsa) != 1)
418 fatal_f("EVP_PKEY_set1_EC_KEY failed");
419 EC_KEY_free(ecdsa);
420 } else
421 fatal_f("unknown key type");
422 k->flags |= SSHKEY_FLAG_EXT;
423 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA",
424 helper->path, helper->nrsa, helper->nec);
425 }
426
427 /*
428 * Make a private PKCS#11-backed certificate by grafting a previously-loaded
429 * PKCS#11 private key and a public certificate key.
430 */
431 int
pkcs11_make_cert(const struct sshkey * priv,const struct sshkey * certpub,struct sshkey ** certprivp)432 pkcs11_make_cert(const struct sshkey *priv,
433 const struct sshkey *certpub, struct sshkey **certprivp)
434 {
435 struct helper *helper = NULL;
436 struct sshkey *ret;
437 int r;
438 RSA *rsa_priv = NULL, *rsa_cert = NULL;
439 EC_KEY *ec_priv = NULL, *ec_cert = NULL;
440
441 debug3_f("private key type %s cert type %s", sshkey_type(priv),
442 sshkey_type(certpub));
443 *certprivp = NULL;
444 if (!sshkey_is_cert(certpub) || sshkey_is_cert(priv) ||
445 !sshkey_equal_public(priv, certpub)) {
446 error_f("private key %s doesn't match cert %s",
447 sshkey_type(priv), sshkey_type(certpub));
448 return SSH_ERR_INVALID_ARGUMENT;
449 }
450 *certprivp = NULL;
451 if (priv->type == KEY_RSA) {
452 if ((rsa_priv = EVP_PKEY_get1_RSA(priv->pkey)) == NULL)
453 fatal_f("no RSA pkey");
454 if ((helper = helper_by_rsa(rsa_priv)) == NULL ||
455 helper->fd == -1)
456 fatal_f("no helper for PKCS11 RSA key");
457 if ((r = sshkey_from_private(priv, &ret)) != 0)
458 fatal_fr(r, "copy key");
459 if ((rsa_cert = EVP_PKEY_get1_RSA(ret->pkey)) == NULL)
460 fatal_f("no RSA cert pkey");
461 if (RSA_set_method(rsa_cert, helper->rsa_meth) != 1)
462 fatal_f("RSA_set_method failed");
463 if (helper->nrsa++ >= INT_MAX)
464 fatal_f("RSA refcount error");
465 if (EVP_PKEY_set1_RSA(ret->pkey, rsa_cert) != 1)
466 fatal_f("EVP_PKEY_set1_RSA failed");
467 RSA_free(rsa_priv);
468 RSA_free(rsa_cert);
469 } else if (priv->type == KEY_ECDSA) {
470 if ((ec_priv = EVP_PKEY_get1_EC_KEY(priv->pkey)) == NULL)
471 fatal_f("no EC pkey");
472 if ((helper = helper_by_ec(ec_priv)) == NULL ||
473 helper->fd == -1)
474 fatal_f("no helper for PKCS11 EC key");
475 if ((r = sshkey_from_private(priv, &ret)) != 0)
476 fatal_fr(r, "copy key");
477 if ((ec_cert = EVP_PKEY_get1_EC_KEY(ret->pkey)) == NULL)
478 fatal_f("no EC cert pkey");
479 if (EC_KEY_set_method(ec_cert, helper->ec_meth) != 1)
480 fatal_f("EC_KEY_set_method failed");
481 if (helper->nec++ >= INT_MAX)
482 fatal_f("EC refcount error");
483 if (EVP_PKEY_set1_EC_KEY(ret->pkey, ec_cert) != 1)
484 fatal_f("EVP_PKEY_set1_EC_KEY failed");
485 EC_KEY_free(ec_priv);
486 EC_KEY_free(ec_cert);
487 } else
488 fatal_f("unknown key type %s", sshkey_type(priv));
489
490 ret->flags |= SSHKEY_FLAG_EXT;
491 if ((r = sshkey_to_certified(ret)) != 0 ||
492 (r = sshkey_cert_copy(certpub, ret)) != 0)
493 fatal_fr(r, "graft certificate");
494 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA",
495 helper->path, helper->nrsa, helper->nec);
496 /* success */
497 *certprivp = ret;
498 return 0;
499 }
500
501 static int
pkcs11_start_helper_methods(struct helper * helper)502 pkcs11_start_helper_methods(struct helper *helper)
503 {
504 int (*ec_init)(EC_KEY *key);
505 int (*ec_copy)(EC_KEY *dest, const EC_KEY *src);
506 int (*ec_set_group)(EC_KEY *key, const EC_GROUP *grp);
507 int (*ec_set_private)(EC_KEY *key, const BIGNUM *priv_key);
508 int (*ec_set_public)(EC_KEY *key, const EC_POINT *pub_key);
509 int (*ec_sign)(int, const unsigned char *, int, unsigned char *,
510 unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) = NULL;
511 RSA_METHOD *rsa_meth;
512 EC_KEY_METHOD *ec_meth;
513
514 if ((ec_meth = EC_KEY_METHOD_new(EC_KEY_OpenSSL())) == NULL)
515 return -1;
516 EC_KEY_METHOD_get_sign(ec_meth, &ec_sign, NULL, NULL);
517 EC_KEY_METHOD_set_sign(ec_meth, ec_sign, NULL, ecdsa_do_sign);
518 EC_KEY_METHOD_get_init(ec_meth, &ec_init, &helper->ec_finish,
519 &ec_copy, &ec_set_group, &ec_set_private, &ec_set_public);
520 EC_KEY_METHOD_set_init(ec_meth, ec_init, ecdsa_do_finish,
521 ec_copy, ec_set_group, ec_set_private, ec_set_public);
522
523 if ((rsa_meth = RSA_meth_dup(RSA_get_default_method())) == NULL)
524 fatal_f("RSA_meth_dup failed");
525 helper->rsa_finish = RSA_meth_get_finish(rsa_meth);
526 if (!RSA_meth_set1_name(rsa_meth, "ssh-pkcs11-helper") ||
527 !RSA_meth_set_priv_enc(rsa_meth, rsa_encrypt) ||
528 !RSA_meth_set_finish(rsa_meth, rsa_finish))
529 fatal_f("failed to prepare method");
530
531 helper->ec_meth = ec_meth;
532 helper->rsa_meth = rsa_meth;
533 return 0;
534 }
535
536 static struct helper *
pkcs11_start_helper(const char * path)537 pkcs11_start_helper(const char *path)
538 {
539 int pair[2];
540 char *prog, *verbosity = NULL;
541 struct helper *helper;
542 pid_t pid;
543
544 if (nhelpers >= INT_MAX)
545 fatal_f("too many helpers");
546 debug3_f("start helper for %s", path);
547 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
548 error_f("socketpair: %s", strerror(errno));
549 return NULL;
550 }
551 helper = xcalloc(1, sizeof(*helper));
552 if (pkcs11_start_helper_methods(helper) == -1) {
553 error_f("pkcs11_start_helper_methods failed");
554 goto fail;
555 }
556 if ((pid = fork()) == -1) {
557 error_f("fork: %s", strerror(errno));
558 fail:
559 close(pair[0]);
560 close(pair[1]);
561 RSA_meth_free(helper->rsa_meth);
562 EC_KEY_METHOD_free(helper->ec_meth);
563 free(helper);
564 return NULL;
565 } else if (pid == 0) {
566 if ((dup2(pair[1], STDIN_FILENO) == -1) ||
567 (dup2(pair[1], STDOUT_FILENO) == -1)) {
568 fprintf(stderr, "dup2: %s\n", strerror(errno));
569 _exit(1);
570 }
571 close(pair[0]);
572 close(pair[1]);
573 prog = getenv("SSH_PKCS11_HELPER");
574 if (prog == NULL || strlen(prog) == 0)
575 prog = _PATH_SSH_PKCS11_HELPER;
576 if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
577 verbosity = "-vvv";
578 debug_f("starting %s %s", prog,
579 verbosity == NULL ? "" : verbosity);
580 execlp(prog, prog, verbosity, (char *)NULL);
581 fprintf(stderr, "exec: %s: %s\n", prog, strerror(errno));
582 _exit(1);
583 }
584 close(pair[1]);
585 helper->fd = pair[0];
586 helper->path = xstrdup(path);
587 helper->pid = pid;
588 debug3_f("helper %zu for \"%s\" on fd %d pid %ld", nhelpers,
589 helper->path, helper->fd, (long)helper->pid);
590 helpers = xrecallocarray(helpers, nhelpers,
591 nhelpers + 1, sizeof(*helpers));
592 helpers[nhelpers++] = helper;
593 return helper;
594 }
595
596 int
pkcs11_add_provider(char * name,char * pin,struct sshkey *** keysp,char *** labelsp)597 pkcs11_add_provider(char *name, char *pin, struct sshkey ***keysp,
598 char ***labelsp)
599 {
600 struct sshkey *k;
601 int r, type;
602 u_char *blob;
603 char *label;
604 size_t blen;
605 u_int nkeys, i;
606 struct sshbuf *msg;
607 struct helper *helper;
608
609 if ((helper = helper_by_provider(name)) == NULL &&
610 (helper = pkcs11_start_helper(name)) == NULL)
611 return -1;
612
613 if ((msg = sshbuf_new()) == NULL)
614 fatal_f("sshbuf_new failed");
615 if ((r = sshbuf_put_u8(msg, SSH_AGENTC_ADD_SMARTCARD_KEY)) != 0 ||
616 (r = sshbuf_put_cstring(msg, name)) != 0 ||
617 (r = sshbuf_put_cstring(msg, pin)) != 0)
618 fatal_fr(r, "compose");
619 send_msg(helper->fd, msg);
620 sshbuf_reset(msg);
621
622 type = recv_msg(helper->fd, msg);
623 if (type == SSH2_AGENT_IDENTITIES_ANSWER) {
624 if ((r = sshbuf_get_u32(msg, &nkeys)) != 0)
625 fatal_fr(r, "parse nkeys");
626 *keysp = xcalloc(nkeys, sizeof(struct sshkey *));
627 if (labelsp)
628 *labelsp = xcalloc(nkeys, sizeof(char *));
629 for (i = 0; i < nkeys; i++) {
630 /* XXX clean up properly instead of fatal() */
631 if ((r = sshbuf_get_string(msg, &blob, &blen)) != 0 ||
632 (r = sshbuf_get_cstring(msg, &label, NULL)) != 0)
633 fatal_fr(r, "parse key");
634 if ((r = sshkey_from_blob(blob, blen, &k)) != 0)
635 fatal_fr(r, "decode key");
636 wrap_key(helper, k);
637 (*keysp)[i] = k;
638 if (labelsp)
639 (*labelsp)[i] = label;
640 else
641 free(label);
642 free(blob);
643 }
644 } else if (type == SSH2_AGENT_FAILURE) {
645 if ((r = sshbuf_get_u32(msg, &nkeys)) != 0)
646 nkeys = -1;
647 } else {
648 nkeys = -1;
649 }
650 sshbuf_free(msg);
651 return (nkeys);
652 }
653
654 int
pkcs11_del_provider(char * name)655 pkcs11_del_provider(char *name)
656 {
657 struct helper *helper;
658
659 /*
660 * ssh-agent deletes keys before calling this, so the helper entry
661 * should be gone before we get here.
662 */
663 debug3_f("delete %s", name);
664 if ((helper = helper_by_provider(name)) != NULL)
665 helper_terminate(helper);
666 return 0;
667 }
668