1 /* $OpenBSD: ssh-pkcs11.c,v 1.26 2018/02/07 02:06:51 jsing 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.
22 #include <sys/types.h>
23 #ifdef HAVE_SYS_TIME_H
24 # include <sys/time.h>
32 #include "openbsd-compat/sys-queue.h"
33 #include "openbsd-compat/openssl-compat.h"
35 #include <openssl/x509.h>
37 #define CRYPTOKI_COMPAT
43 #include "ssh-pkcs11.h"
46 struct pkcs11_slotinfo {
48 CK_SESSION_HANDLE session;
52 struct pkcs11_provider {
55 CK_FUNCTION_LIST *function_list;
59 struct pkcs11_slotinfo *slotinfo;
62 TAILQ_ENTRY(pkcs11_provider) next;
65 TAILQ_HEAD(, pkcs11_provider) pkcs11_providers;
68 struct pkcs11_provider *provider;
70 int (*orig_finish)(RSA *rsa);
71 RSA_METHOD *rsa_method;
76 int pkcs11_interactive = 0;
79 pkcs11_init(int interactive)
81 pkcs11_interactive = interactive;
82 TAILQ_INIT(&pkcs11_providers);
87 * finalize a provider shared libarary, it's no longer usable.
88 * however, there might still be keys referencing this provider,
89 * so the actuall freeing of memory is handled by pkcs11_provider_unref().
90 * this is called when a provider gets unregistered.
93 pkcs11_provider_finalize(struct pkcs11_provider *p)
98 debug("pkcs11_provider_finalize: %p refcount %d valid %d",
99 p, p->refcount, p->valid);
102 for (i = 0; i < p->nslots; i++) {
103 if (p->slotinfo[i].session &&
104 (rv = p->function_list->C_CloseSession(
105 p->slotinfo[i].session)) != CKR_OK)
106 error("C_CloseSession failed: %lu", rv);
108 if ((rv = p->function_list->C_Finalize(NULL)) != CKR_OK)
109 error("C_Finalize failed: %lu", rv);
111 p->function_list = NULL;
116 * remove a reference to the provider.
117 * called when a key gets destroyed or when the provider is unregistered.
120 pkcs11_provider_unref(struct pkcs11_provider *p)
122 debug("pkcs11_provider_unref: %p refcount %d", p, p->refcount);
123 if (--p->refcount <= 0) {
125 error("pkcs11_provider_unref: %p still valid", p);
132 /* unregister all providers, keys might still point to the providers */
134 pkcs11_terminate(void)
136 struct pkcs11_provider *p;
138 while ((p = TAILQ_FIRST(&pkcs11_providers)) != NULL) {
139 TAILQ_REMOVE(&pkcs11_providers, p, next);
140 pkcs11_provider_finalize(p);
141 pkcs11_provider_unref(p);
145 /* lookup provider by name */
146 static struct pkcs11_provider *
147 pkcs11_provider_lookup(char *provider_id)
149 struct pkcs11_provider *p;
151 TAILQ_FOREACH(p, &pkcs11_providers, next) {
152 debug("check %p %s", p, p->name);
153 if (!strcmp(provider_id, p->name))
159 /* unregister provider by name */
161 pkcs11_del_provider(char *provider_id)
163 struct pkcs11_provider *p;
165 if ((p = pkcs11_provider_lookup(provider_id)) != NULL) {
166 TAILQ_REMOVE(&pkcs11_providers, p, next);
167 pkcs11_provider_finalize(p);
168 pkcs11_provider_unref(p);
174 /* openssl callback for freeing an RSA key */
176 pkcs11_rsa_finish(RSA *rsa)
178 struct pkcs11_key *k11;
181 if ((k11 = RSA_get_app_data(rsa)) != NULL) {
182 if (k11->orig_finish)
183 rv = k11->orig_finish(rsa);
185 pkcs11_provider_unref(k11->provider);
186 RSA_meth_free(k11->rsa_method);
193 /* find a single 'obj' for given attributes */
195 pkcs11_find(struct pkcs11_provider *p, CK_ULONG slotidx, CK_ATTRIBUTE *attr,
196 CK_ULONG nattr, CK_OBJECT_HANDLE *obj)
199 CK_SESSION_HANDLE session;
204 f = p->function_list;
205 session = p->slotinfo[slotidx].session;
206 if ((rv = f->C_FindObjectsInit(session, attr, nattr)) != CKR_OK) {
207 error("C_FindObjectsInit failed (nattr %lu): %lu", nattr, rv);
210 if ((rv = f->C_FindObjects(session, obj, 1, &nfound)) != CKR_OK ||
212 debug("C_FindObjects failed (nfound %lu nattr %lu): %lu",
216 if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
217 error("C_FindObjectsFinal failed: %lu", rv);
221 /* openssl callback doing the actual signing operation */
223 pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
226 struct pkcs11_key *k11;
227 struct pkcs11_slotinfo *si;
229 CK_OBJECT_HANDLE obj;
232 CK_OBJECT_CLASS private_key_class = CKO_PRIVATE_KEY;
233 CK_BBOOL true_val = CK_TRUE;
234 CK_MECHANISM mech = {
235 CKM_RSA_PKCS, NULL_PTR, 0
237 CK_ATTRIBUTE key_filter[] = {
238 {CKA_CLASS, NULL, sizeof(private_key_class) },
240 {CKA_SIGN, NULL, sizeof(true_val) }
242 char *pin = NULL, prompt[1024];
245 key_filter[0].pValue = &private_key_class;
246 key_filter[2].pValue = &true_val;
248 if ((k11 = RSA_get_app_data(rsa)) == NULL) {
249 error("RSA_get_app_data failed for rsa %p", rsa);
252 if (!k11->provider || !k11->provider->valid) {
253 error("no pkcs11 (valid) provider for rsa %p", rsa);
256 f = k11->provider->function_list;
257 si = &k11->provider->slotinfo[k11->slotidx];
258 if ((si->token.flags & CKF_LOGIN_REQUIRED) && !si->logged_in) {
259 if (!pkcs11_interactive) {
260 error("need pin entry%s", (si->token.flags &
261 CKF_PROTECTED_AUTHENTICATION_PATH) ?
262 " on reader keypad" : "");
265 if (si->token.flags & CKF_PROTECTED_AUTHENTICATION_PATH)
266 verbose("Deferring PIN entry to reader keypad.");
268 snprintf(prompt, sizeof(prompt),
269 "Enter PIN for '%s': ", si->token.label);
270 pin = read_passphrase(prompt, RP_ALLOW_EOF);
272 return (-1); /* bail out */
274 rv = f->C_Login(si->session, CKU_USER, (u_char *)pin,
275 (pin != NULL) ? strlen(pin) : 0);
277 explicit_bzero(pin, strlen(pin));
280 if (rv != CKR_OK && rv != CKR_USER_ALREADY_LOGGED_IN) {
281 error("C_Login failed: %lu", rv);
286 key_filter[1].pValue = k11->keyid;
287 key_filter[1].ulValueLen = k11->keyid_len;
288 /* try to find object w/CKA_SIGN first, retry w/o */
289 if (pkcs11_find(k11->provider, k11->slotidx, key_filter, 3, &obj) < 0 &&
290 pkcs11_find(k11->provider, k11->slotidx, key_filter, 2, &obj) < 0) {
291 error("cannot find private key");
292 } else if ((rv = f->C_SignInit(si->session, &mech, obj)) != CKR_OK) {
293 error("C_SignInit failed: %lu", rv);
295 /* XXX handle CKR_BUFFER_TOO_SMALL */
296 tlen = RSA_size(rsa);
297 rv = f->C_Sign(si->session, (CK_BYTE *)from, flen, to, &tlen);
301 error("C_Sign failed: %lu", rv);
307 pkcs11_rsa_private_decrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
313 /* redirect private key operations for rsa key to pkcs11 token */
315 pkcs11_rsa_wrap(struct pkcs11_provider *provider, CK_ULONG slotidx,
316 CK_ATTRIBUTE *keyid_attrib, RSA *rsa)
318 struct pkcs11_key *k11;
319 const RSA_METHOD *def = RSA_get_default_method();
321 k11 = xcalloc(1, sizeof(*k11));
322 k11->provider = provider;
323 provider->refcount++; /* provider referenced by RSA key */
324 k11->slotidx = slotidx;
325 /* identify key object on smartcard */
326 k11->keyid_len = keyid_attrib->ulValueLen;
327 if (k11->keyid_len > 0) {
328 k11->keyid = xmalloc(k11->keyid_len);
329 memcpy(k11->keyid, keyid_attrib->pValue, k11->keyid_len);
331 k11->rsa_method = RSA_meth_dup(def);
332 if (k11->rsa_method == NULL)
333 fatal("%s: RSA_meth_dup failed", __func__);
334 k11->orig_finish = RSA_meth_get_finish(def);
335 if (!RSA_meth_set1_name(k11->rsa_method, "pkcs11") ||
336 !RSA_meth_set_priv_enc(k11->rsa_method,
337 pkcs11_rsa_private_encrypt) ||
338 !RSA_meth_set_priv_dec(k11->rsa_method,
339 pkcs11_rsa_private_decrypt) ||
340 !RSA_meth_set_finish(k11->rsa_method, pkcs11_rsa_finish))
341 fatal("%s: setup pkcs11 method failed", __func__);
342 RSA_set_method(rsa, k11->rsa_method);
343 RSA_set_app_data(rsa, k11);
347 /* remove trailing spaces */
349 rmspace(u_char *buf, size_t len)
355 for (i = len - 1; i > 0; i--)
356 if (i == len - 1 || buf[i] == ' ')
363 * open a pkcs11 session and login if required.
364 * if pin == NULL we delay login until key use
367 pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin)
371 CK_SESSION_HANDLE session;
374 f = p->function_list;
375 login_required = p->slotinfo[slotidx].token.flags & CKF_LOGIN_REQUIRED;
376 if (pin && login_required && !strlen(pin)) {
377 error("pin required");
380 if ((rv = f->C_OpenSession(p->slotlist[slotidx], CKF_RW_SESSION|
381 CKF_SERIAL_SESSION, NULL, NULL, &session))
383 error("C_OpenSession failed: %lu", rv);
386 if (login_required && pin) {
387 rv = f->C_Login(session, CKU_USER,
388 (u_char *)pin, strlen(pin));
389 if (rv != CKR_OK && rv != CKR_USER_ALREADY_LOGGED_IN) {
390 error("C_Login failed: %lu", rv);
391 if ((rv = f->C_CloseSession(session)) != CKR_OK)
392 error("C_CloseSession failed: %lu", rv);
395 p->slotinfo[slotidx].logged_in = 1;
397 p->slotinfo[slotidx].session = session;
402 * lookup public keys for token in slot identified by slotidx,
403 * add 'wrapped' public keys to the 'keysp' array and increment nkeys.
404 * keysp points to an (possibly empty) array with *nkeys keys.
406 static int pkcs11_fetch_keys_filter(struct pkcs11_provider *, CK_ULONG,
407 CK_ATTRIBUTE [], CK_ATTRIBUTE [3], struct sshkey ***, int *)
408 __attribute__((__bounded__(__minbytes__,4, 3 * sizeof(CK_ATTRIBUTE))));
411 pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx,
412 struct sshkey ***keysp, int *nkeys)
414 CK_OBJECT_CLASS pubkey_class = CKO_PUBLIC_KEY;
415 CK_OBJECT_CLASS cert_class = CKO_CERTIFICATE;
416 CK_ATTRIBUTE pubkey_filter[] = {
417 { CKA_CLASS, NULL, sizeof(pubkey_class) }
419 CK_ATTRIBUTE cert_filter[] = {
420 { CKA_CLASS, NULL, sizeof(cert_class) }
422 CK_ATTRIBUTE pubkey_attribs[] = {
424 { CKA_MODULUS, NULL, 0 },
425 { CKA_PUBLIC_EXPONENT, NULL, 0 }
427 CK_ATTRIBUTE cert_attribs[] = {
429 { CKA_SUBJECT, NULL, 0 },
430 { CKA_VALUE, NULL, 0 }
432 pubkey_filter[0].pValue = &pubkey_class;
433 cert_filter[0].pValue = &cert_class;
435 if (pkcs11_fetch_keys_filter(p, slotidx, pubkey_filter, pubkey_attribs,
437 pkcs11_fetch_keys_filter(p, slotidx, cert_filter, cert_attribs,
444 pkcs11_key_included(struct sshkey ***keysp, int *nkeys, struct sshkey *key)
448 for (i = 0; i < *nkeys; i++)
449 if (sshkey_equal(key, (*keysp)[i]))
455 have_rsa_key(const RSA *rsa)
457 const BIGNUM *rsa_n, *rsa_e;
459 RSA_get0_key(rsa, &rsa_n, &rsa_e, NULL);
460 return rsa_n != NULL && rsa_e != NULL;
464 pkcs11_fetch_keys_filter(struct pkcs11_provider *p, CK_ULONG slotidx,
465 CK_ATTRIBUTE filter[], CK_ATTRIBUTE attribs[3],
466 struct sshkey ***keysp, int *nkeys)
475 CK_OBJECT_HANDLE obj;
477 CK_SESSION_HANDLE session;
480 f = p->function_list;
481 session = p->slotinfo[slotidx].session;
482 /* setup a filter the looks for public keys */
483 if ((rv = f->C_FindObjectsInit(session, filter, 1)) != CKR_OK) {
484 error("C_FindObjectsInit failed: %lu", rv);
488 /* XXX 3 attributes in attribs[] */
489 for (i = 0; i < 3; i++) {
490 attribs[i].pValue = NULL;
491 attribs[i].ulValueLen = 0;
493 if ((rv = f->C_FindObjects(session, &obj, 1, &nfound)) != CKR_OK
496 /* found a key, so figure out size of the attributes */
497 if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
499 error("C_GetAttributeValue failed: %lu", rv);
503 * Allow CKA_ID (always first attribute) to be empty, but
504 * ensure that none of the others are zero length.
505 * XXX assumes CKA_ID is always first.
507 if (attribs[1].ulValueLen == 0 ||
508 attribs[2].ulValueLen == 0) {
511 /* allocate buffers for attributes */
512 for (i = 0; i < 3; i++) {
513 if (attribs[i].ulValueLen > 0) {
514 attribs[i].pValue = xmalloc(
515 attribs[i].ulValueLen);
520 * retrieve ID, modulus and public exponent of RSA key,
521 * or ID, subject and value for certificates.
524 if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
526 error("C_GetAttributeValue failed: %lu", rv);
527 } else if (attribs[1].type == CKA_MODULUS ) {
528 if ((rsa = RSA_new()) == NULL) {
529 error("RSA_new failed");
531 BIGNUM *rsa_n, *rsa_e;
533 rsa_n = BN_bin2bn(attribs[1].pValue,
534 attribs[1].ulValueLen, NULL);
535 rsa_e = BN_bin2bn(attribs[2].pValue,
536 attribs[2].ulValueLen, NULL);
537 if (rsa_n != NULL && rsa_e != NULL) {
538 if (!RSA_set0_key(rsa,
540 fatal("%s: set key", __func__);
541 rsa_n = rsa_e = NULL; /* transferred */
547 cp = attribs[2].pValue;
548 if ((x509 = X509_new()) == NULL) {
549 error("X509_new failed");
550 } else if (d2i_X509(&x509, &cp, attribs[2].ulValueLen)
552 error("d2i_X509 failed");
553 } else if ((evp = X509_get_pubkey(x509)) == NULL ||
554 EVP_PKEY_base_id(evp) != EVP_PKEY_RSA ||
555 EVP_PKEY_get0_RSA(evp) == NULL) {
556 debug("X509_get_pubkey failed or no rsa");
557 } else if ((rsa = RSAPublicKey_dup(
558 EVP_PKEY_get0_RSA(evp))) == NULL) {
559 error("RSAPublicKey_dup");
563 if (rsa && have_rsa_key(rsa) &&
564 pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
565 if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
566 fatal("sshkey_new failed");
569 key->flags |= SSHKEY_FLAG_EXT;
570 if (pkcs11_key_included(keysp, nkeys, key)) {
573 /* expand key array and add key */
574 *keysp = xrecallocarray(*keysp, *nkeys,
575 *nkeys + 1, sizeof(struct sshkey *));
576 (*keysp)[*nkeys] = key;
578 debug("have %d keys", *nkeys);
583 for (i = 0; i < 3; i++)
584 free(attribs[i].pValue);
586 if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
587 error("C_FindObjectsFinal failed: %lu", rv);
591 /* register a new provider, fails if provider already exists */
593 pkcs11_add_provider(char *provider_id, char *pin, struct sshkey ***keyp)
595 int nkeys, need_finalize = 0;
596 struct pkcs11_provider *p = NULL;
598 CK_RV (*getfunctionlist)(CK_FUNCTION_LIST **);
600 CK_FUNCTION_LIST *f = NULL;
601 CK_TOKEN_INFO *token;
605 if (pkcs11_provider_lookup(provider_id) != NULL) {
606 debug("%s: provider already registered: %s",
607 __func__, provider_id);
610 /* open shared pkcs11-libarary */
611 if ((handle = dlopen(provider_id, RTLD_NOW)) == NULL) {
612 error("dlopen %s failed: %s", provider_id, dlerror());
615 if ((getfunctionlist = dlsym(handle, "C_GetFunctionList")) == NULL) {
616 error("dlsym(C_GetFunctionList) failed: %s", dlerror());
619 p = xcalloc(1, sizeof(*p));
620 p->name = xstrdup(provider_id);
622 /* setup the pkcs11 callbacks */
623 if ((rv = (*getfunctionlist)(&f)) != CKR_OK) {
624 error("C_GetFunctionList for provider %s failed: %lu",
628 p->function_list = f;
629 if ((rv = f->C_Initialize(NULL)) != CKR_OK) {
630 error("C_Initialize for provider %s failed: %lu",
635 if ((rv = f->C_GetInfo(&p->info)) != CKR_OK) {
636 error("C_GetInfo for provider %s failed: %lu",
640 rmspace(p->info.manufacturerID, sizeof(p->info.manufacturerID));
641 rmspace(p->info.libraryDescription, sizeof(p->info.libraryDescription));
642 debug("provider %s: manufacturerID <%s> cryptokiVersion %d.%d"
643 " libraryDescription <%s> libraryVersion %d.%d",
645 p->info.manufacturerID,
646 p->info.cryptokiVersion.major,
647 p->info.cryptokiVersion.minor,
648 p->info.libraryDescription,
649 p->info.libraryVersion.major,
650 p->info.libraryVersion.minor);
651 if ((rv = f->C_GetSlotList(CK_TRUE, NULL, &p->nslots)) != CKR_OK) {
652 error("C_GetSlotList failed: %lu", rv);
655 if (p->nslots == 0) {
656 debug("%s: provider %s returned no slots", __func__,
660 p->slotlist = xcalloc(p->nslots, sizeof(CK_SLOT_ID));
661 if ((rv = f->C_GetSlotList(CK_TRUE, p->slotlist, &p->nslots))
663 error("C_GetSlotList for provider %s failed: %lu",
667 p->slotinfo = xcalloc(p->nslots, sizeof(struct pkcs11_slotinfo));
670 for (i = 0; i < p->nslots; i++) {
671 token = &p->slotinfo[i].token;
672 if ((rv = f->C_GetTokenInfo(p->slotlist[i], token))
674 error("C_GetTokenInfo for provider %s slot %lu "
675 "failed: %lu", provider_id, (unsigned long)i, rv);
678 if ((token->flags & CKF_TOKEN_INITIALIZED) == 0) {
679 debug2("%s: ignoring uninitialised token in "
680 "provider %s slot %lu", __func__,
681 provider_id, (unsigned long)i);
684 rmspace(token->label, sizeof(token->label));
685 rmspace(token->manufacturerID, sizeof(token->manufacturerID));
686 rmspace(token->model, sizeof(token->model));
687 rmspace(token->serialNumber, sizeof(token->serialNumber));
688 debug("provider %s slot %lu: label <%s> manufacturerID <%s> "
689 "model <%s> serial <%s> flags 0x%lx",
690 provider_id, (unsigned long)i,
691 token->label, token->manufacturerID, token->model,
692 token->serialNumber, token->flags);
693 /* open session, login with pin and retrieve public keys */
694 if (pkcs11_open_session(p, i, pin) == 0)
695 pkcs11_fetch_keys(p, i, keyp, &nkeys);
698 TAILQ_INSERT_TAIL(&pkcs11_providers, p, next);
699 p->refcount++; /* add to provider list */
702 debug("%s: provider %s returned no keys", __func__, provider_id);
703 /* don't add the provider, since it does not have any keys */
705 if (need_finalize && (rv = f->C_Finalize(NULL)) != CKR_OK)
706 error("C_Finalize for provider %s failed: %lu",
721 pkcs11_init(int interactive)
727 pkcs11_terminate(void)
732 #endif /* ENABLE_PKCS11 */