1 /* $NetBSD: ssh-pkcs11-client.c,v 1.20 2024/09/24 21:32:19 christos Exp $ */ 2 /* $OpenBSD: ssh-pkcs11-client.c,v 1.20 2024/08/15 00:51:51 djm Exp $ */ 3 4 /* 5 * Copyright (c) 2010 Markus Friedl. All rights reserved. 6 * Copyright (c) 2014 Pedro Martelletto. All rights reserved. 7 * 8 * Permission to use, copy, modify, and distribute this software for any 9 * purpose with or without fee is hereby granted, provided that the above 10 * copyright notice and this permission notice appear in all copies. 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 19 */ 20 #include "includes.h" 21 __RCSID("$NetBSD: ssh-pkcs11-client.c,v 1.20 2024/09/24 21:32:19 christos Exp $"); 22 23 #include <sys/types.h> 24 #include <sys/time.h> 25 #include <sys/socket.h> 26 27 #include <stdarg.h> 28 #include <string.h> 29 #include <unistd.h> 30 #include <errno.h> 31 #include <limits.h> 32 33 #include <openssl/ecdsa.h> 34 #include <openssl/rsa.h> 35 36 #include "pathnames.h" 37 #include "xmalloc.h" 38 #include "sshbuf.h" 39 #include "log.h" 40 #include "misc.h" 41 #include "sshkey.h" 42 #include "authfd.h" 43 #include "atomicio.h" 44 #include "ssh-pkcs11.h" 45 #include "ssherr.h" 46 47 /* borrows code from sftp-server and ssh-agent */ 48 49 /* 50 * Maintain a list of ssh-pkcs11-helper subprocesses. These may be looked up 51 * by provider path or their unique EC/RSA METHOD pointers. 52 */ 53 struct helper { 54 char *path; 55 pid_t pid; 56 int fd; 57 RSA_METHOD *rsa_meth; 58 EC_KEY_METHOD *ec_meth; 59 int (*rsa_finish)(RSA *rsa); 60 void (*ec_finish)(EC_KEY *key); 61 size_t nrsa, nec; /* number of active keys of each type */ 62 }; 63 static struct helper **helpers; 64 static size_t nhelpers; 65 66 static struct helper * 67 helper_by_provider(const char *path) 68 { 69 size_t i; 70 71 for (i = 0; i < nhelpers; i++) { 72 if (helpers[i] == NULL || helpers[i]->path == NULL || 73 helpers[i]->fd == -1) 74 continue; 75 if (strcmp(helpers[i]->path, path) == 0) 76 return helpers[i]; 77 } 78 return NULL; 79 } 80 81 static struct helper * 82 helper_by_rsa(const RSA *rsa) 83 { 84 size_t i; 85 const RSA_METHOD *meth; 86 87 if ((meth = RSA_get_method(rsa)) == NULL) 88 return NULL; 89 for (i = 0; i < nhelpers; i++) { 90 if (helpers[i] != NULL && helpers[i]->rsa_meth == meth) 91 return helpers[i]; 92 } 93 return NULL; 94 95 } 96 97 static struct helper * 98 helper_by_ec(const EC_KEY *ec) 99 { 100 size_t i; 101 const EC_KEY_METHOD *meth; 102 103 if ((meth = EC_KEY_get_method(ec)) == NULL) 104 return NULL; 105 for (i = 0; i < nhelpers; i++) { 106 if (helpers[i] != NULL && helpers[i]->ec_meth == meth) 107 return helpers[i]; 108 } 109 return NULL; 110 111 } 112 113 static void 114 helper_free(struct helper *helper) 115 { 116 size_t i; 117 int found = 0; 118 119 if (helper == NULL) 120 return; 121 if (helper->path == NULL || helper->ec_meth == NULL || 122 helper->rsa_meth == NULL) 123 fatal_f("inconsistent helper"); 124 debug3_f("free helper for provider %s", helper->path); 125 for (i = 0; i < nhelpers; i++) { 126 if (helpers[i] == helper) { 127 if (found) 128 fatal_f("helper recorded more than once"); 129 found = 1; 130 } 131 else if (found) 132 helpers[i - 1] = helpers[i]; 133 } 134 if (found) { 135 helpers = xrecallocarray(helpers, nhelpers, 136 nhelpers - 1, sizeof(*helpers)); 137 nhelpers--; 138 } 139 free(helper->path); 140 EC_KEY_METHOD_free(helper->ec_meth); 141 RSA_meth_free(helper->rsa_meth); 142 free(helper); 143 } 144 145 static void 146 helper_terminate(struct helper *helper) 147 { 148 if (helper == NULL) { 149 return; 150 } else if (helper->fd == -1) { 151 debug3_f("already terminated"); 152 } else { 153 debug3_f("terminating helper for %s; " 154 "remaining %zu RSA %zu ECDSA", 155 helper->path, helper->nrsa, helper->nec); 156 close(helper->fd); 157 /* XXX waitpid() */ 158 helper->fd = -1; 159 helper->pid = -1; 160 } 161 /* 162 * Don't delete the helper entry until there are no remaining keys 163 * that reference it. Otherwise, any signing operation would call 164 * a free'd METHOD pointer and that would be bad. 165 */ 166 if (helper->nrsa == 0 && helper->nec == 0) 167 helper_free(helper); 168 } 169 170 static void 171 send_msg(int fd, struct sshbuf *m) 172 { 173 u_char buf[4]; 174 size_t mlen = sshbuf_len(m); 175 int r; 176 177 if (fd == -1) 178 return; 179 POKE_U32(buf, mlen); 180 if (atomicio(vwrite, fd, buf, 4) != 4 || 181 atomicio(vwrite, fd, sshbuf_mutable_ptr(m), 182 sshbuf_len(m)) != sshbuf_len(m)) 183 error("write to helper failed"); 184 if ((r = sshbuf_consume(m, mlen)) != 0) 185 fatal_fr(r, "consume"); 186 } 187 188 static int 189 recv_msg(int fd, struct sshbuf *m) 190 { 191 u_int l, len; 192 u_char c, buf[1024]; 193 int r; 194 195 sshbuf_reset(m); 196 if (fd == -1) 197 return 0; /* XXX */ 198 if ((len = atomicio(read, fd, buf, 4)) != 4) { 199 error("read from helper failed: %u", len); 200 return (0); /* XXX */ 201 } 202 len = PEEK_U32(buf); 203 if (len > 256 * 1024) 204 fatal("response too long: %u", len); 205 /* read len bytes into m */ 206 while (len > 0) { 207 l = len; 208 if (l > sizeof(buf)) 209 l = sizeof(buf); 210 if (atomicio(read, fd, buf, l) != l) { 211 error("response from helper failed."); 212 return (0); /* XXX */ 213 } 214 if ((r = sshbuf_put(m, buf, l)) != 0) 215 fatal_fr(r, "sshbuf_put"); 216 len -= l; 217 } 218 if ((r = sshbuf_get_u8(m, &c)) != 0) 219 fatal_fr(r, "parse type"); 220 return c; 221 } 222 223 int 224 pkcs11_init(int interactive) 225 { 226 return 0; 227 } 228 229 void 230 pkcs11_terminate(void) 231 { 232 size_t i; 233 234 debug3_f("terminating %zu helpers", nhelpers); 235 for (i = 0; i < nhelpers; i++) 236 helper_terminate(helpers[i]); 237 } 238 239 static int 240 rsa_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa, int padding) 241 { 242 struct sshkey *key = NULL; 243 struct sshbuf *msg = NULL; 244 u_char *blob = NULL, *signature = NULL; 245 size_t blen, slen = 0; 246 int r, ret = -1; 247 struct helper *helper; 248 249 if ((helper = helper_by_rsa(rsa)) == NULL || helper->fd == -1) 250 fatal_f("no helper for PKCS11 key"); 251 debug3_f("signing with PKCS11 provider %s", helper->path); 252 if (padding != RSA_PKCS1_PADDING) 253 goto fail; 254 if ((key = sshkey_new(KEY_UNSPEC)) == NULL) { 255 error_f("sshkey_new failed"); 256 goto fail; 257 } 258 if ((key->pkey = EVP_PKEY_new()) == NULL || 259 EVP_PKEY_set1_RSA(key->pkey, rsa) != 1) { 260 error_f("pkey setup failed"); 261 goto fail; 262 } 263 264 key->type = KEY_RSA; 265 if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) { 266 error_fr(r, "encode key"); 267 goto fail; 268 } 269 if ((msg = sshbuf_new()) == NULL) 270 fatal_f("sshbuf_new failed"); 271 if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 || 272 (r = sshbuf_put_string(msg, blob, blen)) != 0 || 273 (r = sshbuf_put_string(msg, from, flen)) != 0 || 274 (r = sshbuf_put_u32(msg, 0)) != 0) 275 fatal_fr(r, "compose"); 276 send_msg(helper->fd, msg); 277 sshbuf_reset(msg); 278 279 if (recv_msg(helper->fd, msg) == SSH2_AGENT_SIGN_RESPONSE) { 280 if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0) 281 fatal_fr(r, "parse"); 282 if (slen <= (size_t)RSA_size(rsa)) { 283 memcpy(to, signature, slen); 284 ret = slen; 285 } 286 free(signature); 287 } 288 fail: 289 free(blob); 290 sshkey_free(key); 291 sshbuf_free(msg); 292 return (ret); 293 } 294 295 static int 296 rsa_finish(RSA *rsa) 297 { 298 struct helper *helper; 299 300 if ((helper = helper_by_rsa(rsa)) == NULL) 301 fatal_f("no helper for PKCS11 key"); 302 debug3_f("free PKCS11 RSA key for provider %s", helper->path); 303 if (helper->rsa_finish != NULL) 304 helper->rsa_finish(rsa); 305 if (helper->nrsa == 0) 306 fatal_f("RSA refcount error"); 307 helper->nrsa--; 308 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", 309 helper->path, helper->nrsa, helper->nec); 310 if (helper->nrsa == 0 && helper->nec == 0) 311 helper_terminate(helper); 312 return 1; 313 } 314 315 static ECDSA_SIG * 316 ecdsa_do_sign(const unsigned char *dgst, int dgst_len, const BIGNUM *inv, 317 const BIGNUM *rp, EC_KEY *ec) 318 { 319 struct sshkey *key = NULL; 320 struct sshbuf *msg = NULL; 321 ECDSA_SIG *ret = NULL; 322 const u_char *cp; 323 u_char *blob = NULL, *signature = NULL; 324 size_t blen, slen = 0; 325 int r, nid; 326 struct helper *helper; 327 328 if ((helper = helper_by_ec(ec)) == NULL || helper->fd == -1) 329 fatal_f("no helper for PKCS11 key"); 330 debug3_f("signing with PKCS11 provider %s", helper->path); 331 332 if ((key = sshkey_new(KEY_UNSPEC)) == NULL) { 333 error_f("sshkey_new failed"); 334 goto fail; 335 } 336 if ((key->pkey = EVP_PKEY_new()) == NULL || 337 EVP_PKEY_set1_EC_KEY(key->pkey, ec) != 1) { 338 error("pkey setup failed"); 339 goto fail; 340 } 341 if ((nid = sshkey_ecdsa_pkey_to_nid(key->pkey)) < 0) { 342 error("couldn't get curve nid"); 343 goto fail; 344 } 345 key->ecdsa_nid = nid; 346 key->type = KEY_ECDSA; 347 348 if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) { 349 error_fr(r, "encode key"); 350 goto fail; 351 } 352 if ((msg = sshbuf_new()) == NULL) 353 fatal_f("sshbuf_new failed"); 354 if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 || 355 (r = sshbuf_put_string(msg, blob, blen)) != 0 || 356 (r = sshbuf_put_string(msg, dgst, dgst_len)) != 0 || 357 (r = sshbuf_put_u32(msg, 0)) != 0) 358 fatal_fr(r, "compose"); 359 send_msg(helper->fd, msg); 360 sshbuf_reset(msg); 361 362 if (recv_msg(helper->fd, msg) == SSH2_AGENT_SIGN_RESPONSE) { 363 if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0) 364 fatal_fr(r, "parse"); 365 cp = signature; 366 ret = d2i_ECDSA_SIG(NULL, &cp, slen); 367 free(signature); 368 } 369 370 fail: 371 free(blob); 372 sshkey_free(key); 373 sshbuf_free(msg); 374 return (ret); 375 } 376 377 static void 378 ecdsa_do_finish(EC_KEY *ec) 379 { 380 struct helper *helper; 381 382 if ((helper = helper_by_ec(ec)) == NULL) 383 fatal_f("no helper for PKCS11 key"); 384 debug3_f("free PKCS11 ECDSA key for provider %s", helper->path); 385 if (helper->ec_finish != NULL) 386 helper->ec_finish(ec); 387 if (helper->nec == 0) 388 fatal_f("ECDSA refcount error"); 389 helper->nec--; 390 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", 391 helper->path, helper->nrsa, helper->nec); 392 if (helper->nrsa == 0 && helper->nec == 0) 393 helper_terminate(helper); 394 } 395 396 /* redirect private key crypto operations to the ssh-pkcs11-helper */ 397 static void 398 wrap_key(struct helper *helper, struct sshkey *k) 399 { 400 RSA *rsa = NULL; 401 EC_KEY *ecdsa = NULL; 402 403 debug3_f("wrap %s for provider %s", sshkey_type(k), helper->path); 404 if (k->type == KEY_RSA) { 405 if ((rsa = EVP_PKEY_get1_RSA(k->pkey)) == NULL) 406 fatal_f("no RSA key"); 407 if (RSA_set_method(rsa, helper->rsa_meth) != 1) 408 fatal_f("RSA_set_method failed"); 409 if (helper->nrsa++ >= INT_MAX) 410 fatal_f("RSA refcount error"); 411 if (EVP_PKEY_set1_RSA(k->pkey, rsa) != 1) 412 fatal_f("EVP_PKEY_set1_RSA failed"); 413 RSA_free(rsa); 414 } else if (k->type == KEY_ECDSA) { 415 if ((ecdsa = EVP_PKEY_get1_EC_KEY(k->pkey)) == NULL) 416 fatal_f("no ECDSA key"); 417 if (EC_KEY_set_method(ecdsa, helper->ec_meth) != 1) 418 fatal_f("EC_KEY_set_method failed"); 419 if (helper->nec++ >= INT_MAX) 420 fatal_f("EC refcount error"); 421 if (EVP_PKEY_set1_EC_KEY(k->pkey, ecdsa) != 1) 422 fatal_f("EVP_PKEY_set1_EC_KEY failed"); 423 EC_KEY_free(ecdsa); 424 } else 425 fatal_f("unknown key type"); 426 k->flags |= SSHKEY_FLAG_EXT; 427 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", 428 helper->path, helper->nrsa, helper->nec); 429 } 430 431 /* 432 * Make a private PKCS#11-backed certificate by grafting a previously-loaded 433 * PKCS#11 private key and a public certificate key. 434 */ 435 int 436 pkcs11_make_cert(const struct sshkey *priv, 437 const struct sshkey *certpub, struct sshkey **certprivp) 438 { 439 struct helper *helper = NULL; 440 struct sshkey *ret; 441 int r; 442 RSA *rsa_priv = NULL, *rsa_cert = NULL; 443 EC_KEY *ec_priv = NULL, *ec_cert = NULL; 444 445 debug3_f("private key type %s cert type %s", sshkey_type(priv), 446 sshkey_type(certpub)); 447 *certprivp = NULL; 448 if (!sshkey_is_cert(certpub) || sshkey_is_cert(priv) || 449 !sshkey_equal_public(priv, certpub)) { 450 error_f("private key %s doesn't match cert %s", 451 sshkey_type(priv), sshkey_type(certpub)); 452 return SSH_ERR_INVALID_ARGUMENT; 453 } 454 *certprivp = NULL; 455 if (priv->type == KEY_RSA) { 456 if ((rsa_priv = EVP_PKEY_get1_RSA(priv->pkey)) == NULL) 457 fatal_f("no RSA pkey"); 458 if ((helper = helper_by_rsa(rsa_priv)) == NULL || 459 helper->fd == -1) 460 fatal_f("no helper for PKCS11 RSA key"); 461 if ((r = sshkey_from_private(priv, &ret)) != 0) 462 fatal_fr(r, "copy key"); 463 if ((rsa_cert = EVP_PKEY_get1_RSA(ret->pkey)) == NULL) 464 fatal_f("no RSA cert pkey"); 465 if (RSA_set_method(rsa_cert, helper->rsa_meth) != 1) 466 fatal_f("RSA_set_method failed"); 467 if (helper->nrsa++ >= INT_MAX) 468 fatal_f("RSA refcount error"); 469 if (EVP_PKEY_set1_RSA(ret->pkey, rsa_cert) != 1) 470 fatal_f("EVP_PKEY_set1_RSA failed"); 471 RSA_free(rsa_priv); 472 RSA_free(rsa_cert); 473 } else if (priv->type == KEY_ECDSA) { 474 if ((ec_priv = EVP_PKEY_get1_EC_KEY(priv->pkey)) == NULL) 475 fatal_f("no EC pkey"); 476 if ((helper = helper_by_ec(ec_priv)) == NULL || 477 helper->fd == -1) 478 fatal_f("no helper for PKCS11 EC key"); 479 if ((r = sshkey_from_private(priv, &ret)) != 0) 480 fatal_fr(r, "copy key"); 481 if ((ec_cert = EVP_PKEY_get1_EC_KEY(ret->pkey)) == NULL) 482 fatal_f("no EC cert pkey"); 483 if (EC_KEY_set_method(ec_cert, helper->ec_meth) != 1) 484 fatal_f("EC_KEY_set_method failed"); 485 if (helper->nec++ >= INT_MAX) 486 fatal_f("EC refcount error"); 487 if (EVP_PKEY_set1_EC_KEY(ret->pkey, ec_cert) != 1) 488 fatal_f("EVP_PKEY_set1_EC_KEY failed"); 489 EC_KEY_free(ec_priv); 490 EC_KEY_free(ec_cert); 491 } else 492 fatal_f("unknown key type %s", sshkey_type(priv)); 493 494 ret->flags |= SSHKEY_FLAG_EXT; 495 if ((r = sshkey_to_certified(ret)) != 0 || 496 (r = sshkey_cert_copy(certpub, ret)) != 0) 497 fatal_fr(r, "graft certificate"); 498 debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", 499 helper->path, helper->nrsa, helper->nec); 500 /* success */ 501 *certprivp = ret; 502 return 0; 503 } 504 505 static int 506 pkcs11_start_helper_methods(struct helper *helper) 507 { 508 int (*ec_init)(EC_KEY *key); 509 int (*ec_copy)(EC_KEY *dest, const EC_KEY *src); 510 int (*ec_set_group)(EC_KEY *key, const EC_GROUP *grp); 511 int (*ec_set_private)(EC_KEY *key, const BIGNUM *priv_key); 512 int (*ec_set_public)(EC_KEY *key, const EC_POINT *pub_key); 513 int (*ec_sign)(int, const unsigned char *, int, unsigned char *, 514 unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) = NULL; 515 RSA_METHOD *rsa_meth; 516 EC_KEY_METHOD *ec_meth; 517 518 if ((ec_meth = EC_KEY_METHOD_new(EC_KEY_OpenSSL())) == NULL) 519 return -1; 520 EC_KEY_METHOD_get_sign(ec_meth, &ec_sign, NULL, NULL); 521 EC_KEY_METHOD_set_sign(ec_meth, ec_sign, NULL, ecdsa_do_sign); 522 EC_KEY_METHOD_get_init(ec_meth, &ec_init, &helper->ec_finish, 523 &ec_copy, &ec_set_group, &ec_set_private, &ec_set_public); 524 EC_KEY_METHOD_set_init(ec_meth, ec_init, ecdsa_do_finish, 525 ec_copy, ec_set_group, ec_set_private, ec_set_public); 526 527 if ((rsa_meth = RSA_meth_dup(RSA_get_default_method())) == NULL) 528 fatal_f("RSA_meth_dup failed"); 529 helper->rsa_finish = RSA_meth_get_finish(rsa_meth); 530 if (!RSA_meth_set1_name(rsa_meth, "ssh-pkcs11-helper") || 531 !RSA_meth_set_priv_enc(rsa_meth, rsa_encrypt) || 532 !RSA_meth_set_finish(rsa_meth, rsa_finish)) 533 fatal_f("failed to prepare method"); 534 535 helper->ec_meth = ec_meth; 536 helper->rsa_meth = rsa_meth; 537 return 0; 538 } 539 540 static struct helper * 541 pkcs11_start_helper(const char *path) 542 { 543 int pair[2]; 544 const char *prog, *verbosity = NULL; 545 struct helper *helper; 546 pid_t pid; 547 548 if (nhelpers >= INT_MAX) 549 fatal_f("too many helpers"); 550 debug3_f("start helper for %s", path); 551 if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) { 552 error_f("socketpair: %s", strerror(errno)); 553 return NULL; 554 } 555 helper = xcalloc(1, sizeof(*helper)); 556 if (pkcs11_start_helper_methods(helper) == -1) { 557 error_f("pkcs11_start_helper_methods failed"); 558 goto fail; 559 } 560 if ((pid = fork()) == -1) { 561 error_f("fork: %s", strerror(errno)); 562 fail: 563 close(pair[0]); 564 close(pair[1]); 565 RSA_meth_free(helper->rsa_meth); 566 EC_KEY_METHOD_free(helper->ec_meth); 567 free(helper); 568 return NULL; 569 } else if (pid == 0) { 570 if ((dup2(pair[1], STDIN_FILENO) == -1) || 571 (dup2(pair[1], STDOUT_FILENO) == -1)) { 572 fprintf(stderr, "dup2: %s\n", strerror(errno)); 573 _exit(1); 574 } 575 close(pair[0]); 576 close(pair[1]); 577 prog = getenv("SSH_PKCS11_HELPER"); 578 if (prog == NULL || strlen(prog) == 0) 579 prog = _PATH_SSH_PKCS11_HELPER; 580 if (log_level_get() >= SYSLOG_LEVEL_DEBUG1) 581 verbosity = "-vvv"; 582 debug_f("starting %s %s", prog, 583 verbosity == NULL ? "" : verbosity); 584 execlp(prog, prog, verbosity, (char *)NULL); 585 fprintf(stderr, "exec: %s: %s\n", prog, strerror(errno)); 586 _exit(1); 587 } 588 close(pair[1]); 589 helper->fd = pair[0]; 590 helper->path = xstrdup(path); 591 helper->pid = pid; 592 debug3_f("helper %zu for \"%s\" on fd %d pid %ld", nhelpers, 593 helper->path, helper->fd, (long)helper->pid); 594 helpers = xrecallocarray(helpers, nhelpers, 595 nhelpers + 1, sizeof(*helpers)); 596 helpers[nhelpers++] = helper; 597 return helper; 598 } 599 600 int 601 pkcs11_add_provider(char *name, char *pin, struct sshkey ***keysp, 602 char ***labelsp) 603 { 604 struct sshkey *k; 605 int r, type; 606 u_char *blob; 607 char *label; 608 size_t blen; 609 u_int nkeys, i; 610 struct sshbuf *msg; 611 struct helper *helper; 612 613 if ((helper = helper_by_provider(name)) == NULL && 614 (helper = pkcs11_start_helper(name)) == NULL) 615 return -1; 616 617 if ((msg = sshbuf_new()) == NULL) 618 fatal_f("sshbuf_new failed"); 619 if ((r = sshbuf_put_u8(msg, SSH_AGENTC_ADD_SMARTCARD_KEY)) != 0 || 620 (r = sshbuf_put_cstring(msg, name)) != 0 || 621 (r = sshbuf_put_cstring(msg, pin)) != 0) 622 fatal_fr(r, "compose"); 623 send_msg(helper->fd, msg); 624 sshbuf_reset(msg); 625 626 type = recv_msg(helper->fd, msg); 627 if (type == SSH2_AGENT_IDENTITIES_ANSWER) { 628 if ((r = sshbuf_get_u32(msg, &nkeys)) != 0) 629 fatal_fr(r, "parse nkeys"); 630 *keysp = xcalloc(nkeys, sizeof(struct sshkey *)); 631 if (labelsp) 632 *labelsp = xcalloc(nkeys, sizeof(char *)); 633 for (i = 0; i < nkeys; i++) { 634 /* XXX clean up properly instead of fatal() */ 635 if ((r = sshbuf_get_string(msg, &blob, &blen)) != 0 || 636 (r = sshbuf_get_cstring(msg, &label, NULL)) != 0) 637 fatal_fr(r, "parse key"); 638 if ((r = sshkey_from_blob(blob, blen, &k)) != 0) 639 fatal_fr(r, "decode key"); 640 wrap_key(helper, k); 641 (*keysp)[i] = k; 642 if (labelsp) 643 (*labelsp)[i] = label; 644 else 645 free(label); 646 free(blob); 647 } 648 } else if (type == SSH2_AGENT_FAILURE) { 649 if ((r = sshbuf_get_u32(msg, &nkeys)) != 0) 650 nkeys = -1; 651 } else { 652 nkeys = -1; 653 } 654 sshbuf_free(msg); 655 return (nkeys); 656 } 657 658 int 659 pkcs11_del_provider(char *name) 660 { 661 struct helper *helper; 662 663 /* 664 * ssh-agent deletes keys before calling this, so the helper entry 665 * should be gone before we get here. 666 */ 667 debug3_f("delete %s", name); 668 if ((helper = helper_by_provider(name)) != NULL) 669 helper_terminate(helper); 670 return 0; 671 } 672