xref: /openbsd-src/usr.bin/ssh/ssh-pkcs11.c (revision ae3cb403620ab940fbaabb3055fac045a63d56b7)
1 /* $OpenBSD: ssh-pkcs11.c,v 1.25 2017/05/31 09:15:42 deraadt Exp $ */
2 /*
3  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
4  *
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.
8  *
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.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <stdarg.h>
21 #include <stdio.h>
22 
23 #include <string.h>
24 #include <dlfcn.h>
25 
26 #include <openssl/x509.h>
27 
28 #define CRYPTOKI_COMPAT
29 #include "pkcs11.h"
30 
31 #include "log.h"
32 #include "misc.h"
33 #include "sshkey.h"
34 #include "ssh-pkcs11.h"
35 #include "xmalloc.h"
36 
37 struct pkcs11_slotinfo {
38 	CK_TOKEN_INFO		token;
39 	CK_SESSION_HANDLE	session;
40 	int			logged_in;
41 };
42 
43 struct pkcs11_provider {
44 	char			*name;
45 	void			*handle;
46 	CK_FUNCTION_LIST	*function_list;
47 	CK_INFO			info;
48 	CK_ULONG		nslots;
49 	CK_SLOT_ID		*slotlist;
50 	struct pkcs11_slotinfo	*slotinfo;
51 	int			valid;
52 	int			refcount;
53 	TAILQ_ENTRY(pkcs11_provider) next;
54 };
55 
56 TAILQ_HEAD(, pkcs11_provider) pkcs11_providers;
57 
58 struct pkcs11_key {
59 	struct pkcs11_provider	*provider;
60 	CK_ULONG		slotidx;
61 	int			(*orig_finish)(RSA *rsa);
62 	RSA_METHOD		rsa_method;
63 	char			*keyid;
64 	int			keyid_len;
65 };
66 
67 int pkcs11_interactive = 0;
68 
69 int
70 pkcs11_init(int interactive)
71 {
72 	pkcs11_interactive = interactive;
73 	TAILQ_INIT(&pkcs11_providers);
74 	return (0);
75 }
76 
77 /*
78  * finalize a provider shared libarary, it's no longer usable.
79  * however, there might still be keys referencing this provider,
80  * so the actuall freeing of memory is handled by pkcs11_provider_unref().
81  * this is called when a provider gets unregistered.
82  */
83 static void
84 pkcs11_provider_finalize(struct pkcs11_provider *p)
85 {
86 	CK_RV rv;
87 	CK_ULONG i;
88 
89 	debug("pkcs11_provider_finalize: %p refcount %d valid %d",
90 	    p, p->refcount, p->valid);
91 	if (!p->valid)
92 		return;
93 	for (i = 0; i < p->nslots; i++) {
94 		if (p->slotinfo[i].session &&
95 		    (rv = p->function_list->C_CloseSession(
96 		    p->slotinfo[i].session)) != CKR_OK)
97 			error("C_CloseSession failed: %lu", rv);
98 	}
99 	if ((rv = p->function_list->C_Finalize(NULL)) != CKR_OK)
100 		error("C_Finalize failed: %lu", rv);
101 	p->valid = 0;
102 	p->function_list = NULL;
103 #ifdef HAVE_DLOPEN
104 	dlclose(p->handle);
105 #endif
106 }
107 
108 /*
109  * remove a reference to the provider.
110  * called when a key gets destroyed or when the provider is unregistered.
111  */
112 static void
113 pkcs11_provider_unref(struct pkcs11_provider *p)
114 {
115 	debug("pkcs11_provider_unref: %p refcount %d", p, p->refcount);
116 	if (--p->refcount <= 0) {
117 		if (p->valid)
118 			error("pkcs11_provider_unref: %p still valid", p);
119 		free(p->slotlist);
120 		free(p->slotinfo);
121 		free(p);
122 	}
123 }
124 
125 /* unregister all providers, keys might still point to the providers */
126 void
127 pkcs11_terminate(void)
128 {
129 	struct pkcs11_provider *p;
130 
131 	while ((p = TAILQ_FIRST(&pkcs11_providers)) != NULL) {
132 		TAILQ_REMOVE(&pkcs11_providers, p, next);
133 		pkcs11_provider_finalize(p);
134 		pkcs11_provider_unref(p);
135 	}
136 }
137 
138 /* lookup provider by name */
139 static struct pkcs11_provider *
140 pkcs11_provider_lookup(char *provider_id)
141 {
142 	struct pkcs11_provider *p;
143 
144 	TAILQ_FOREACH(p, &pkcs11_providers, next) {
145 		debug("check %p %s", p, p->name);
146 		if (!strcmp(provider_id, p->name))
147 			return (p);
148 	}
149 	return (NULL);
150 }
151 
152 /* unregister provider by name */
153 int
154 pkcs11_del_provider(char *provider_id)
155 {
156 	struct pkcs11_provider *p;
157 
158 	if ((p = pkcs11_provider_lookup(provider_id)) != NULL) {
159 		TAILQ_REMOVE(&pkcs11_providers, p, next);
160 		pkcs11_provider_finalize(p);
161 		pkcs11_provider_unref(p);
162 		return (0);
163 	}
164 	return (-1);
165 }
166 
167 /* openssl callback for freeing an RSA key */
168 static int
169 pkcs11_rsa_finish(RSA *rsa)
170 {
171 	struct pkcs11_key	*k11;
172 	int rv = -1;
173 
174 	if ((k11 = RSA_get_app_data(rsa)) != NULL) {
175 		if (k11->orig_finish)
176 			rv = k11->orig_finish(rsa);
177 		if (k11->provider)
178 			pkcs11_provider_unref(k11->provider);
179 		free(k11->keyid);
180 		free(k11);
181 	}
182 	return (rv);
183 }
184 
185 /* find a single 'obj' for given attributes */
186 static int
187 pkcs11_find(struct pkcs11_provider *p, CK_ULONG slotidx, CK_ATTRIBUTE *attr,
188     CK_ULONG nattr, CK_OBJECT_HANDLE *obj)
189 {
190 	CK_FUNCTION_LIST	*f;
191 	CK_SESSION_HANDLE	session;
192 	CK_ULONG		nfound = 0;
193 	CK_RV			rv;
194 	int			ret = -1;
195 
196 	f = p->function_list;
197 	session = p->slotinfo[slotidx].session;
198 	if ((rv = f->C_FindObjectsInit(session, attr, nattr)) != CKR_OK) {
199 		error("C_FindObjectsInit failed (nattr %lu): %lu", nattr, rv);
200 		return (-1);
201 	}
202 	if ((rv = f->C_FindObjects(session, obj, 1, &nfound)) != CKR_OK ||
203 	    nfound != 1) {
204 		debug("C_FindObjects failed (nfound %lu nattr %lu): %lu",
205 		    nfound, nattr, rv);
206 	} else
207 		ret = 0;
208 	if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
209 		error("C_FindObjectsFinal failed: %lu", rv);
210 	return (ret);
211 }
212 
213 /* openssl callback doing the actual signing operation */
214 static int
215 pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
216     int padding)
217 {
218 	struct pkcs11_key	*k11;
219 	struct pkcs11_slotinfo	*si;
220 	CK_FUNCTION_LIST	*f;
221 	CK_OBJECT_HANDLE	obj;
222 	CK_ULONG		tlen = 0;
223 	CK_RV			rv;
224 	CK_OBJECT_CLASS		private_key_class = CKO_PRIVATE_KEY;
225 	CK_BBOOL		true_val = CK_TRUE;
226 	CK_MECHANISM		mech = {
227 		CKM_RSA_PKCS, NULL_PTR, 0
228 	};
229 	CK_ATTRIBUTE		key_filter[] = {
230 		{CKA_CLASS, &private_key_class, sizeof(private_key_class) },
231 		{CKA_ID, NULL, 0},
232 		{CKA_SIGN, &true_val, sizeof(true_val) }
233 	};
234 	char			*pin = NULL, prompt[1024];
235 	int			rval = -1;
236 
237 	if ((k11 = RSA_get_app_data(rsa)) == NULL) {
238 		error("RSA_get_app_data failed for rsa %p", rsa);
239 		return (-1);
240 	}
241 	if (!k11->provider || !k11->provider->valid) {
242 		error("no pkcs11 (valid) provider for rsa %p", rsa);
243 		return (-1);
244 	}
245 	f = k11->provider->function_list;
246 	si = &k11->provider->slotinfo[k11->slotidx];
247 	if ((si->token.flags & CKF_LOGIN_REQUIRED) && !si->logged_in) {
248 		if (!pkcs11_interactive) {
249 			error("need pin entry%s", (si->token.flags &
250 			    CKF_PROTECTED_AUTHENTICATION_PATH) ?
251 			    " on reader keypad" : "");
252 			return (-1);
253 		}
254 		if (si->token.flags & CKF_PROTECTED_AUTHENTICATION_PATH)
255 			verbose("Deferring PIN entry to reader keypad.");
256 		else {
257 			snprintf(prompt, sizeof(prompt),
258 			    "Enter PIN for '%s': ", si->token.label);
259 			pin = read_passphrase(prompt, RP_ALLOW_EOF);
260 			if (pin == NULL)
261 				return (-1);	/* bail out */
262 		}
263 		rv = f->C_Login(si->session, CKU_USER, (u_char *)pin,
264 		    (pin != NULL) ? strlen(pin) : 0);
265 		if (pin != NULL) {
266 			explicit_bzero(pin, strlen(pin));
267 			free(pin);
268 		}
269 		if (rv != CKR_OK && rv != CKR_USER_ALREADY_LOGGED_IN) {
270 			error("C_Login failed: %lu", rv);
271 			return (-1);
272 		}
273 		si->logged_in = 1;
274 	}
275 	key_filter[1].pValue = k11->keyid;
276 	key_filter[1].ulValueLen = k11->keyid_len;
277 	/* try to find object w/CKA_SIGN first, retry w/o */
278 	if (pkcs11_find(k11->provider, k11->slotidx, key_filter, 3, &obj) < 0 &&
279 	    pkcs11_find(k11->provider, k11->slotidx, key_filter, 2, &obj) < 0) {
280 		error("cannot find private key");
281 	} else if ((rv = f->C_SignInit(si->session, &mech, obj)) != CKR_OK) {
282 		error("C_SignInit failed: %lu", rv);
283 	} else {
284 		/* XXX handle CKR_BUFFER_TOO_SMALL */
285 		tlen = RSA_size(rsa);
286 		rv = f->C_Sign(si->session, (CK_BYTE *)from, flen, to, &tlen);
287 		if (rv == CKR_OK)
288 			rval = tlen;
289 		else
290 			error("C_Sign failed: %lu", rv);
291 	}
292 	return (rval);
293 }
294 
295 static int
296 pkcs11_rsa_private_decrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
297     int padding)
298 {
299 	return (-1);
300 }
301 
302 /* redirect private key operations for rsa key to pkcs11 token */
303 static int
304 pkcs11_rsa_wrap(struct pkcs11_provider *provider, CK_ULONG slotidx,
305     CK_ATTRIBUTE *keyid_attrib, RSA *rsa)
306 {
307 	struct pkcs11_key	*k11;
308 	const RSA_METHOD	*def = RSA_get_default_method();
309 
310 	k11 = xcalloc(1, sizeof(*k11));
311 	k11->provider = provider;
312 	provider->refcount++;	/* provider referenced by RSA key */
313 	k11->slotidx = slotidx;
314 	/* identify key object on smartcard */
315 	k11->keyid_len = keyid_attrib->ulValueLen;
316 	if (k11->keyid_len > 0) {
317 		k11->keyid = xmalloc(k11->keyid_len);
318 		memcpy(k11->keyid, keyid_attrib->pValue, k11->keyid_len);
319 	}
320 	k11->orig_finish = def->finish;
321 	memcpy(&k11->rsa_method, def, sizeof(k11->rsa_method));
322 	k11->rsa_method.name = "pkcs11";
323 	k11->rsa_method.rsa_priv_enc = pkcs11_rsa_private_encrypt;
324 	k11->rsa_method.rsa_priv_dec = pkcs11_rsa_private_decrypt;
325 	k11->rsa_method.finish = pkcs11_rsa_finish;
326 	RSA_set_method(rsa, &k11->rsa_method);
327 	RSA_set_app_data(rsa, k11);
328 	return (0);
329 }
330 
331 /* remove trailing spaces */
332 static void
333 rmspace(u_char *buf, size_t len)
334 {
335 	size_t i;
336 
337 	if (!len)
338 		return;
339 	for (i = len - 1;  i > 0; i--)
340 		if (i == len - 1 || buf[i] == ' ')
341 			buf[i] = '\0';
342 		else
343 			break;
344 }
345 
346 /*
347  * open a pkcs11 session and login if required.
348  * if pin == NULL we delay login until key use
349  */
350 static int
351 pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin)
352 {
353 	CK_RV			rv;
354 	CK_FUNCTION_LIST	*f;
355 	CK_SESSION_HANDLE	session;
356 	int			login_required;
357 
358 	f = p->function_list;
359 	login_required = p->slotinfo[slotidx].token.flags & CKF_LOGIN_REQUIRED;
360 	if (pin && login_required && !strlen(pin)) {
361 		error("pin required");
362 		return (-1);
363 	}
364 	if ((rv = f->C_OpenSession(p->slotlist[slotidx], CKF_RW_SESSION|
365 	    CKF_SERIAL_SESSION, NULL, NULL, &session))
366 	    != CKR_OK) {
367 		error("C_OpenSession failed: %lu", rv);
368 		return (-1);
369 	}
370 	if (login_required && pin) {
371 		rv = f->C_Login(session, CKU_USER,
372 		    (u_char *)pin, strlen(pin));
373 		if (rv != CKR_OK && rv != CKR_USER_ALREADY_LOGGED_IN) {
374 			error("C_Login failed: %lu", rv);
375 			if ((rv = f->C_CloseSession(session)) != CKR_OK)
376 				error("C_CloseSession failed: %lu", rv);
377 			return (-1);
378 		}
379 		p->slotinfo[slotidx].logged_in = 1;
380 	}
381 	p->slotinfo[slotidx].session = session;
382 	return (0);
383 }
384 
385 /*
386  * lookup public keys for token in slot identified by slotidx,
387  * add 'wrapped' public keys to the 'keysp' array and increment nkeys.
388  * keysp points to an (possibly empty) array with *nkeys keys.
389  */
390 static int pkcs11_fetch_keys_filter(struct pkcs11_provider *, CK_ULONG,
391     CK_ATTRIBUTE [], CK_ATTRIBUTE [3], struct sshkey ***, int *)
392 	__attribute__((__bounded__(__minbytes__,4, 3 * sizeof(CK_ATTRIBUTE))));
393 
394 static int
395 pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx,
396     struct sshkey ***keysp, int *nkeys)
397 {
398 	CK_OBJECT_CLASS		pubkey_class = CKO_PUBLIC_KEY;
399 	CK_OBJECT_CLASS		cert_class = CKO_CERTIFICATE;
400 	CK_ATTRIBUTE		pubkey_filter[] = {
401 		{ CKA_CLASS, &pubkey_class, sizeof(pubkey_class) }
402 	};
403 	CK_ATTRIBUTE		cert_filter[] = {
404 		{ CKA_CLASS, &cert_class, sizeof(cert_class) }
405 	};
406 	CK_ATTRIBUTE		pubkey_attribs[] = {
407 		{ CKA_ID, NULL, 0 },
408 		{ CKA_MODULUS, NULL, 0 },
409 		{ CKA_PUBLIC_EXPONENT, NULL, 0 }
410 	};
411 	CK_ATTRIBUTE		cert_attribs[] = {
412 		{ CKA_ID, NULL, 0 },
413 		{ CKA_SUBJECT, NULL, 0 },
414 		{ CKA_VALUE, NULL, 0 }
415 	};
416 
417 	if (pkcs11_fetch_keys_filter(p, slotidx, pubkey_filter, pubkey_attribs,
418 	    keysp, nkeys) < 0 ||
419 	    pkcs11_fetch_keys_filter(p, slotidx, cert_filter, cert_attribs,
420 	    keysp, nkeys) < 0)
421 		return (-1);
422 	return (0);
423 }
424 
425 static int
426 pkcs11_key_included(struct sshkey ***keysp, int *nkeys, struct sshkey *key)
427 {
428 	int i;
429 
430 	for (i = 0; i < *nkeys; i++)
431 		if (sshkey_equal(key, (*keysp)[i]))
432 			return (1);
433 	return (0);
434 }
435 
436 static int
437 pkcs11_fetch_keys_filter(struct pkcs11_provider *p, CK_ULONG slotidx,
438     CK_ATTRIBUTE filter[], CK_ATTRIBUTE attribs[3],
439     struct sshkey ***keysp, int *nkeys)
440 {
441 	struct sshkey		*key;
442 	RSA			*rsa;
443 	X509 			*x509;
444 	EVP_PKEY		*evp;
445 	int			i;
446 	const u_char		*cp;
447 	CK_RV			rv;
448 	CK_OBJECT_HANDLE	obj;
449 	CK_ULONG		nfound;
450 	CK_SESSION_HANDLE	session;
451 	CK_FUNCTION_LIST	*f;
452 
453 	f = p->function_list;
454 	session = p->slotinfo[slotidx].session;
455 	/* setup a filter the looks for public keys */
456 	if ((rv = f->C_FindObjectsInit(session, filter, 1)) != CKR_OK) {
457 		error("C_FindObjectsInit failed: %lu", rv);
458 		return (-1);
459 	}
460 	while (1) {
461 		/* XXX 3 attributes in attribs[] */
462 		for (i = 0; i < 3; i++) {
463 			attribs[i].pValue = NULL;
464 			attribs[i].ulValueLen = 0;
465 		}
466 		if ((rv = f->C_FindObjects(session, &obj, 1, &nfound)) != CKR_OK
467 		    || nfound == 0)
468 			break;
469 		/* found a key, so figure out size of the attributes */
470 		if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
471 		    != CKR_OK) {
472 			error("C_GetAttributeValue failed: %lu", rv);
473 			continue;
474 		}
475 		/*
476 		 * Allow CKA_ID (always first attribute) to be empty, but
477 		 * ensure that none of the others are zero length.
478 		 * XXX assumes CKA_ID is always first.
479 		 */
480 		if (attribs[1].ulValueLen == 0 ||
481 		    attribs[2].ulValueLen == 0) {
482 			continue;
483 		}
484 		/* allocate buffers for attributes */
485 		for (i = 0; i < 3; i++) {
486 			if (attribs[i].ulValueLen > 0) {
487 				attribs[i].pValue = xmalloc(
488 				    attribs[i].ulValueLen);
489 			}
490 		}
491 
492 		/*
493 		 * retrieve ID, modulus and public exponent of RSA key,
494 		 * or ID, subject and value for certificates.
495 		 */
496 		rsa = NULL;
497 		if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
498 		    != CKR_OK) {
499 			error("C_GetAttributeValue failed: %lu", rv);
500 		} else if (attribs[1].type == CKA_MODULUS ) {
501 			if ((rsa = RSA_new()) == NULL) {
502 				error("RSA_new failed");
503 			} else {
504 				rsa->n = BN_bin2bn(attribs[1].pValue,
505 				    attribs[1].ulValueLen, NULL);
506 				rsa->e = BN_bin2bn(attribs[2].pValue,
507 				    attribs[2].ulValueLen, NULL);
508 			}
509 		} else {
510 			cp = attribs[2].pValue;
511 			if ((x509 = X509_new()) == NULL) {
512 				error("X509_new failed");
513 			} else if (d2i_X509(&x509, &cp, attribs[2].ulValueLen)
514 			    == NULL) {
515 				error("d2i_X509 failed");
516 			} else if ((evp = X509_get_pubkey(x509)) == NULL ||
517 			    evp->type != EVP_PKEY_RSA ||
518 			    evp->pkey.rsa == NULL) {
519 				debug("X509_get_pubkey failed or no rsa");
520 			} else if ((rsa = RSAPublicKey_dup(evp->pkey.rsa))
521 			    == NULL) {
522 				error("RSAPublicKey_dup");
523 			}
524 			if (x509)
525 				X509_free(x509);
526 		}
527 		if (rsa && rsa->n && rsa->e &&
528 		    pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
529 			if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
530 				fatal("sshkey_new failed");
531 			key->rsa = rsa;
532 			key->type = KEY_RSA;
533 			key->flags |= SSHKEY_FLAG_EXT;
534 			if (pkcs11_key_included(keysp, nkeys, key)) {
535 				sshkey_free(key);
536 			} else {
537 				/* expand key array and add key */
538 				*keysp = xrecallocarray(*keysp, *nkeys,
539 				    *nkeys + 1, sizeof(struct sshkey *));
540 				(*keysp)[*nkeys] = key;
541 				*nkeys = *nkeys + 1;
542 				debug("have %d keys", *nkeys);
543 			}
544 		} else if (rsa) {
545 			RSA_free(rsa);
546 		}
547 		for (i = 0; i < 3; i++)
548 			free(attribs[i].pValue);
549 	}
550 	if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
551 		error("C_FindObjectsFinal failed: %lu", rv);
552 	return (0);
553 }
554 
555 #ifdef HAVE_DLOPEN
556 /* register a new provider, fails if provider already exists */
557 int
558 pkcs11_add_provider(char *provider_id, char *pin, struct sshkey ***keyp)
559 {
560 	int nkeys, need_finalize = 0;
561 	struct pkcs11_provider *p = NULL;
562 	void *handle = NULL;
563 	CK_RV (*getfunctionlist)(CK_FUNCTION_LIST **);
564 	CK_RV rv;
565 	CK_FUNCTION_LIST *f = NULL;
566 	CK_TOKEN_INFO *token;
567 	CK_ULONG i;
568 
569 	*keyp = NULL;
570 	if (pkcs11_provider_lookup(provider_id) != NULL) {
571 		debug("%s: provider already registered: %s",
572 		    __func__, provider_id);
573 		goto fail;
574 	}
575 	/* open shared pkcs11-libarary */
576 	if ((handle = dlopen(provider_id, RTLD_NOW)) == NULL) {
577 		error("dlopen %s failed: %s", provider_id, dlerror());
578 		goto fail;
579 	}
580 	if ((getfunctionlist = dlsym(handle, "C_GetFunctionList")) == NULL) {
581 		error("dlsym(C_GetFunctionList) failed: %s", dlerror());
582 		goto fail;
583 	}
584 	p = xcalloc(1, sizeof(*p));
585 	p->name = xstrdup(provider_id);
586 	p->handle = handle;
587 	/* setup the pkcs11 callbacks */
588 	if ((rv = (*getfunctionlist)(&f)) != CKR_OK) {
589 		error("C_GetFunctionList for provider %s failed: %lu",
590 		    provider_id, rv);
591 		goto fail;
592 	}
593 	p->function_list = f;
594 	if ((rv = f->C_Initialize(NULL)) != CKR_OK) {
595 		error("C_Initialize for provider %s failed: %lu",
596 		    provider_id, rv);
597 		goto fail;
598 	}
599 	need_finalize = 1;
600 	if ((rv = f->C_GetInfo(&p->info)) != CKR_OK) {
601 		error("C_GetInfo for provider %s failed: %lu",
602 		    provider_id, rv);
603 		goto fail;
604 	}
605 	rmspace(p->info.manufacturerID, sizeof(p->info.manufacturerID));
606 	rmspace(p->info.libraryDescription, sizeof(p->info.libraryDescription));
607 	debug("provider %s: manufacturerID <%s> cryptokiVersion %d.%d"
608 	    " libraryDescription <%s> libraryVersion %d.%d",
609 	    provider_id,
610 	    p->info.manufacturerID,
611 	    p->info.cryptokiVersion.major,
612 	    p->info.cryptokiVersion.minor,
613 	    p->info.libraryDescription,
614 	    p->info.libraryVersion.major,
615 	    p->info.libraryVersion.minor);
616 	if ((rv = f->C_GetSlotList(CK_TRUE, NULL, &p->nslots)) != CKR_OK) {
617 		error("C_GetSlotList failed: %lu", rv);
618 		goto fail;
619 	}
620 	if (p->nslots == 0) {
621 		debug("%s: provider %s returned no slots", __func__,
622 		    provider_id);
623 		goto fail;
624 	}
625 	p->slotlist = xcalloc(p->nslots, sizeof(CK_SLOT_ID));
626 	if ((rv = f->C_GetSlotList(CK_TRUE, p->slotlist, &p->nslots))
627 	    != CKR_OK) {
628 		error("C_GetSlotList for provider %s failed: %lu",
629 		    provider_id, rv);
630 		goto fail;
631 	}
632 	p->slotinfo = xcalloc(p->nslots, sizeof(struct pkcs11_slotinfo));
633 	p->valid = 1;
634 	nkeys = 0;
635 	for (i = 0; i < p->nslots; i++) {
636 		token = &p->slotinfo[i].token;
637 		if ((rv = f->C_GetTokenInfo(p->slotlist[i], token))
638 		    != CKR_OK) {
639 			error("C_GetTokenInfo for provider %s slot %lu "
640 			    "failed: %lu", provider_id, (unsigned long)i, rv);
641 			continue;
642 		}
643 		if ((token->flags & CKF_TOKEN_INITIALIZED) == 0) {
644 			debug2("%s: ignoring uninitialised token in "
645 			    "provider %s slot %lu", __func__,
646 			    provider_id, (unsigned long)i);
647 			continue;
648 		}
649 		rmspace(token->label, sizeof(token->label));
650 		rmspace(token->manufacturerID, sizeof(token->manufacturerID));
651 		rmspace(token->model, sizeof(token->model));
652 		rmspace(token->serialNumber, sizeof(token->serialNumber));
653 		debug("provider %s slot %lu: label <%s> manufacturerID <%s> "
654 		    "model <%s> serial <%s> flags 0x%lx",
655 		    provider_id, (unsigned long)i,
656 		    token->label, token->manufacturerID, token->model,
657 		    token->serialNumber, token->flags);
658 		/* open session, login with pin and retrieve public keys */
659 		if (pkcs11_open_session(p, i, pin) == 0)
660 			pkcs11_fetch_keys(p, i, keyp, &nkeys);
661 	}
662 	if (nkeys > 0) {
663 		TAILQ_INSERT_TAIL(&pkcs11_providers, p, next);
664 		p->refcount++;	/* add to provider list */
665 		return (nkeys);
666 	}
667 	debug("%s: provider %s returned no keys", __func__, provider_id);
668 	/* don't add the provider, since it does not have any keys */
669 fail:
670 	if (need_finalize && (rv = f->C_Finalize(NULL)) != CKR_OK)
671 		error("C_Finalize for provider %s failed: %lu",
672 		    provider_id, rv);
673 	if (p) {
674 		free(p->slotlist);
675 		free(p->slotinfo);
676 		free(p);
677 	}
678 	if (handle)
679 		dlclose(handle);
680 	return (-1);
681 }
682 #else
683 int
684 pkcs11_add_provider(char *provider_id, char *pin, struct sshkey ***keyp)
685 {
686 	error("dlopen() not supported");
687 	return (-1);
688 }
689 #endif
690