Annotation of src/usr.bin/ssh/ssh-pkcs11.c, Revision 1.6
1.6 ! markus 1: /* $OpenBSD: ssh-pkcs11.c,v 1.5 2010/04/15 20:32:55 markus Exp $ */
1.1 markus 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: #define CRYPTOKI_COMPAT
27: #include "pkcs11.h"
28:
29: #include "log.h"
30: #include "misc.h"
31: #include "key.h"
32: #include "ssh-pkcs11.h"
33: #include "xmalloc.h"
34:
35: struct pkcs11_slotinfo {
36: CK_TOKEN_INFO token;
37: CK_SESSION_HANDLE session;
38: int logged_in;
39: };
40:
41: struct pkcs11_provider {
42: char *name;
43: void *handle;
44: CK_FUNCTION_LIST *function_list;
45: CK_INFO info;
46: CK_ULONG nslots;
47: CK_SLOT_ID *slotlist;
48: struct pkcs11_slotinfo *slotinfo;
49: int valid;
50: int refcount;
51: TAILQ_ENTRY(pkcs11_provider) next;
52: };
53:
54: TAILQ_HEAD(, pkcs11_provider) pkcs11_providers;
55:
56: struct pkcs11_key {
57: struct pkcs11_provider *provider;
58: CK_ULONG slotidx;
59: int (*orig_finish)(RSA *rsa);
60: RSA_METHOD rsa_method;
61: char *keyid;
62: int keyid_len;
63: };
64:
65: int pkcs11_interactive = 0;
66:
67: int
68: pkcs11_init(int interactive)
69: {
70: pkcs11_interactive = interactive;
71: TAILQ_INIT(&pkcs11_providers);
72: return (0);
73: }
74:
75: /*
76: * finalize a provider shared libarary, it's no longer usable.
77: * however, there might still be keys referencing this provider,
78: * so the actuall freeing of memory is handled by pkcs11_provider_unref().
79: * this is called when a provider gets unregistered.
80: */
81: static void
82: pkcs11_provider_finalize(struct pkcs11_provider *p)
83: {
84: CK_RV rv;
85: CK_ULONG i;
86:
87: debug("pkcs11_provider_finalize: %p refcount %d valid %d",
88: p, p->refcount, p->valid);
89: if (!p->valid)
90: return;
91: for (i = 0; i < p->nslots; i++) {
92: if (p->slotinfo[i].session &&
93: (rv = p->function_list->C_CloseSession(
94: p->slotinfo[i].session)) != CKR_OK)
95: error("C_CloseSession failed: %lu", rv);
96: }
97: if ((rv = p->function_list->C_Finalize(NULL)) != CKR_OK)
98: error("C_Finalize failed: %lu", rv);
99: p->valid = 0;
100: p->function_list = NULL;
1.3 deraadt 101: #ifdef HAVE_DLOPEN
1.1 markus 102: dlclose(p->handle);
1.3 deraadt 103: #endif
1.1 markus 104: }
105:
106: /*
107: * remove a reference to the provider.
108: * called when a key gets destroyed or when the provider is unregistered.
109: */
110: static void
111: pkcs11_provider_unref(struct pkcs11_provider *p)
112: {
113: debug("pkcs11_provider_unref: %p refcount %d", p, p->refcount);
114: if (--p->refcount <= 0) {
115: if (p->valid)
116: error("pkcs11_provider_unref: %p still valid", p);
117: xfree(p->slotlist);
118: xfree(p->slotinfo);
119: xfree(p);
120: }
121: }
122:
123: /* unregister all providers, keys might still point to the providers */
124: void
125: pkcs11_terminate(void)
126: {
127: struct pkcs11_provider *p;
128:
129: while ((p = TAILQ_FIRST(&pkcs11_providers)) != NULL) {
130: TAILQ_REMOVE(&pkcs11_providers, p, next);
131: pkcs11_provider_finalize(p);
132: pkcs11_provider_unref(p);
133: }
134: }
135:
136: /* lookup provider by name */
137: static struct pkcs11_provider *
138: pkcs11_provider_lookup(char *provider_id)
139: {
140: struct pkcs11_provider *p;
141:
142: TAILQ_FOREACH(p, &pkcs11_providers, next) {
143: debug("check %p %s", p, p->name);
144: if (!strcmp(provider_id, p->name))
145: return (p);
146: }
147: return (NULL);
148: }
149:
150: /* unregister provider by name */
151: int
152: pkcs11_del_provider(char *provider_id)
153: {
154: struct pkcs11_provider *p;
155:
156: if ((p = pkcs11_provider_lookup(provider_id)) != NULL) {
157: TAILQ_REMOVE(&pkcs11_providers, p, next);
158: pkcs11_provider_finalize(p);
159: pkcs11_provider_unref(p);
160: return (0);
161: }
162: return (-1);
163: }
164:
165: /* openssl callback for freeing an RSA key */
166: static int
167: pkcs11_rsa_finish(RSA *rsa)
168: {
169: struct pkcs11_key *k11;
170: int rv = -1;
171:
172: if ((k11 = RSA_get_app_data(rsa)) != NULL) {
173: if (k11->orig_finish)
174: rv = k11->orig_finish(rsa);
175: if (k11->provider)
176: pkcs11_provider_unref(k11->provider);
177: if (k11->keyid)
178: xfree(k11->keyid);
179: xfree(k11);
180: }
181: return (rv);
182: }
183:
1.5 markus 184: /* find a single 'obj' for given attributes */
185: static int
186: pkcs11_find(struct pkcs11_provider *p, CK_ULONG slotidx, CK_ATTRIBUTE *attr,
187: CK_ULONG nattr, CK_OBJECT_HANDLE *obj)
188: {
189: CK_FUNCTION_LIST *f;
190: CK_SESSION_HANDLE session;
191: CK_ULONG nfound = 0;
192: CK_RV rv;
193: int ret = -1;
194:
195: f = p->function_list;
196: session = p->slotinfo[slotidx].session;
197: if ((rv = f->C_FindObjectsInit(session, attr, nattr)) != CKR_OK) {
198: error("C_FindObjectsInit failed (nattr %lu): %lu", nattr, rv);
199: return (-1);
200: }
201: if ((rv = f->C_FindObjects(session, obj, 1, &nfound)) != CKR_OK ||
202: nfound != 1) {
203: debug("C_FindObjects failed (nfound %lu nattr %lu): %lu",
204: nfound, nattr, rv);
205: } else
206: ret = 0;
207: if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
208: error("C_FindObjectsFinal failed: %lu", rv);
209: return (ret);
210: }
211:
1.1 markus 212: /* openssl callback doing the actual signing operation */
213: static int
214: pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
215: int padding)
216: {
217: struct pkcs11_key *k11;
218: struct pkcs11_slotinfo *si;
219: CK_FUNCTION_LIST *f;
220: CK_OBJECT_HANDLE obj;
1.5 markus 221: CK_ULONG tlen = 0;
1.1 markus 222: CK_RV rv;
223: CK_OBJECT_CLASS private_key_class = CKO_PRIVATE_KEY;
224: CK_BBOOL true = CK_TRUE;
225: CK_MECHANISM mech = {
226: CKM_RSA_PKCS, NULL_PTR, 0
227: };
228: CK_ATTRIBUTE key_filter[] = {
229: {CKA_CLASS, &private_key_class, sizeof(private_key_class) },
230: {CKA_ID, NULL, 0},
231: {CKA_SIGN, &true, sizeof(true) }
232: };
233: char *pin, prompt[1024];
234: int rval = -1;
235:
236: if ((k11 = RSA_get_app_data(rsa)) == NULL) {
237: error("RSA_get_app_data failed for rsa %p", rsa);
238: return (-1);
239: }
240: if (!k11->provider || !k11->provider->valid) {
241: error("no pkcs11 (valid) provider for rsa %p", rsa);
242: return (-1);
243: }
244: f = k11->provider->function_list;
245: si = &k11->provider->slotinfo[k11->slotidx];
246: if ((si->token.flags & CKF_LOGIN_REQUIRED) && !si->logged_in) {
247: if (!pkcs11_interactive) {
248: error("need pin");
249: return (-1);
250: }
251: snprintf(prompt, sizeof(prompt), "Enter PIN for '%s': ",
252: si->token.label);
253: pin = read_passphrase(prompt, RP_ALLOW_EOF);
254: if (pin == NULL)
255: return (-1); /* bail out */
256: if ((rv = f->C_Login(si->session, CKU_USER, pin, strlen(pin)))
257: != CKR_OK) {
258: xfree(pin);
259: error("C_Login failed: %lu", rv);
260: return (-1);
261: }
262: xfree(pin);
263: si->logged_in = 1;
264: }
265: key_filter[1].pValue = k11->keyid;
266: key_filter[1].ulValueLen = k11->keyid_len;
1.5 markus 267: /* try to find object w/CKA_SIGN first, retry w/o */
268: if (pkcs11_find(k11->provider, k11->slotidx, key_filter, 3, &obj) < 0 &&
269: pkcs11_find(k11->provider, k11->slotidx, key_filter, 2, &obj) < 0) {
270: error("cannot find private key");
1.1 markus 271: } else if ((rv = f->C_SignInit(si->session, &mech, obj)) != CKR_OK) {
272: error("C_SignInit failed: %lu", rv);
273: } else {
274: /* XXX handle CKR_BUFFER_TOO_SMALL */
275: tlen = RSA_size(rsa);
276: rv = f->C_Sign(si->session, (CK_BYTE *)from, flen, to, &tlen);
277: if (rv == CKR_OK)
278: rval = tlen;
279: else
280: error("C_Sign failed: %lu", rv);
281: }
282: return (rval);
283: }
284:
285: static int
286: pkcs11_rsa_private_decrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
287: int padding)
288: {
289: return (-1);
290: }
291:
292: /* redirect private key operations for rsa key to pkcs11 token */
293: static int
294: pkcs11_rsa_wrap(struct pkcs11_provider *provider, CK_ULONG slotidx,
295: CK_ATTRIBUTE *keyid_attrib, RSA *rsa)
296: {
297: struct pkcs11_key *k11;
298: const RSA_METHOD *def = RSA_get_default_method();
299:
300: k11 = xcalloc(1, sizeof(*k11));
301: k11->provider = provider;
302: provider->refcount++; /* provider referenced by RSA key */
303: k11->slotidx = slotidx;
304: /* identify key object on smartcard */
305: k11->keyid_len = keyid_attrib->ulValueLen;
306: k11->keyid = xmalloc(k11->keyid_len);
307: memcpy(k11->keyid, keyid_attrib->pValue, k11->keyid_len);
308: k11->orig_finish = def->finish;
309: memcpy(&k11->rsa_method, def, sizeof(k11->rsa_method));
310: k11->rsa_method.name = "pkcs11";
311: k11->rsa_method.rsa_priv_enc = pkcs11_rsa_private_encrypt;
312: k11->rsa_method.rsa_priv_dec = pkcs11_rsa_private_decrypt;
313: k11->rsa_method.finish = pkcs11_rsa_finish;
314: RSA_set_method(rsa, &k11->rsa_method);
315: RSA_set_app_data(rsa, k11);
316: return (0);
317: }
318:
319: /* remove trailing spaces */
320: static void
321: rmspace(char *buf, size_t len)
322: {
323: size_t i;
324:
325: if (!len)
326: return;
327: for (i = len - 1; i > 0; i--)
328: if (i == len - 1 || buf[i] == ' ')
329: buf[i] = '\0';
330: else
331: break;
332: }
333:
334: /*
335: * open a pkcs11 session and login if required.
336: * if pin == NULL we delay login until key use
337: */
338: static int
339: pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin)
340: {
341: CK_RV rv;
342: CK_FUNCTION_LIST *f;
343: CK_SESSION_HANDLE session;
344: int login_required;
345:
346: f = p->function_list;
347: login_required = p->slotinfo[slotidx].token.flags & CKF_LOGIN_REQUIRED;
348: if (pin && login_required && !strlen(pin)) {
349: error("pin required");
350: return (-1);
351: }
352: if ((rv = f->C_OpenSession(p->slotlist[slotidx], CKF_RW_SESSION|
353: CKF_SERIAL_SESSION, NULL, NULL, &session))
354: != CKR_OK) {
355: error("C_OpenSession failed: %lu", rv);
356: return (-1);
357: }
358: if (login_required && pin) {
359: if ((rv = f->C_Login(session, CKU_USER, pin, strlen(pin)))
360: != CKR_OK) {
361: error("C_Login failed: %lu", rv);
362: if ((rv = f->C_CloseSession(session)) != CKR_OK)
363: error("C_CloseSession failed: %lu", rv);
364: return (-1);
365: }
366: p->slotinfo[slotidx].logged_in = 1;
367: }
368: p->slotinfo[slotidx].session = session;
369: return (0);
370: }
371:
372: /*
373: * lookup public keys for token in slot identified by slotidx,
374: * add 'wrapped' public keys to the 'keysp' array and increment nkeys.
375: * keysp points to an (possibly empty) array with *nkeys keys.
376: */
377: static int
378: pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx, Key ***keysp,
379: int *nkeys)
380: {
381: Key *key;
382: RSA *rsa;
383: int i;
384: CK_RV rv;
385: CK_OBJECT_HANDLE obj;
386: CK_ULONG nfound;
387: CK_SESSION_HANDLE session;
388: CK_FUNCTION_LIST *f;
389: CK_OBJECT_CLASS pubkey_class = CKO_PUBLIC_KEY;
390: CK_ATTRIBUTE pubkey_filter[] = {
391: { CKA_CLASS, &pubkey_class, sizeof(pubkey_class) }
392: };
393: CK_ATTRIBUTE attribs[] = {
394: { CKA_ID, NULL, 0 },
395: { CKA_MODULUS, NULL, 0 },
396: { CKA_PUBLIC_EXPONENT, NULL, 0 }
397: };
398:
399: f = p->function_list;
400: session = p->slotinfo[slotidx].session;
401: /* setup a filter the looks for public keys */
402: if ((rv = f->C_FindObjectsInit(session, pubkey_filter, 1)) != CKR_OK) {
403: error("C_FindObjectsInit failed: %lu", rv);
404: return (-1);
405: }
406: while (1) {
407: /* XXX 3 attributes in attribs[] */
408: for (i = 0; i < 3; i++) {
409: attribs[i].pValue = NULL;
410: attribs[i].ulValueLen = 0;
411: }
412: if ((rv = f->C_FindObjects(session, &obj, 1, &nfound)) != CKR_OK
413: || nfound == 0)
414: break;
415: /* found a key, so figure out size of the attributes */
416: if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
417: != CKR_OK) {
418: error("C_GetAttributeValue failed: %lu", rv);
419: continue;
420: }
1.6 ! markus 421: /* check that none of the attributes are zero length */
! 422: if (attribs[0].ulValueLen == 0 ||
! 423: attribs[1].ulValueLen == 0 ||
! 424: attribs[2].ulValueLen == 0) {
! 425: continue;
! 426: }
! 427: /* allocate buffers for attributes */
1.1 markus 428: for (i = 0; i < 3; i++)
429: attribs[i].pValue = xmalloc(attribs[i].ulValueLen);
430: /* retrieve ID, modulus and public exponent of RSA key */
431: if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
432: != CKR_OK) {
433: error("C_GetAttributeValue failed: %lu", rv);
434: } else if ((rsa = RSA_new()) == NULL) {
435: error("RSA_new failed");
436: } else {
437: rsa->n = BN_bin2bn(attribs[1].pValue,
438: attribs[1].ulValueLen, NULL);
439: rsa->e = BN_bin2bn(attribs[2].pValue,
440: attribs[2].ulValueLen, NULL);
441: if (rsa->n && rsa->e &&
442: pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
443: key = key_new(KEY_UNSPEC);
444: key->rsa = rsa;
445: key->type = KEY_RSA;
446: key->flags |= KEY_FLAG_EXT;
447: /* expand key array and add key */
448: *keysp = xrealloc(*keysp, *nkeys + 1,
449: sizeof(Key *));
450: (*keysp)[*nkeys] = key;
451: *nkeys = *nkeys + 1;
452: debug("have %d keys", *nkeys);
453: } else {
454: RSA_free(rsa);
455: }
456: }
457: for (i = 0; i < 3; i++)
458: xfree(attribs[i].pValue);
459: }
460: if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
461: error("C_FindObjectsFinal failed: %lu", rv);
462: return (0);
463: }
464:
1.2 markus 465: #ifdef HAVE_DLOPEN
1.1 markus 466: /* register a new provider, fails if provider already exists */
467: int
468: pkcs11_add_provider(char *provider_id, char *pin, Key ***keyp)
469: {
470: int nkeys, need_finalize = 0;
471: struct pkcs11_provider *p = NULL;
472: void *handle = NULL;
473: CK_RV (*getfunctionlist)(CK_FUNCTION_LIST **);
474: CK_RV rv;
475: CK_FUNCTION_LIST *f = NULL;
476: CK_TOKEN_INFO *token;
477: CK_ULONG i;
478:
479: *keyp = NULL;
480: if (pkcs11_provider_lookup(provider_id) != NULL) {
481: error("provider already registered: %s", provider_id);
482: goto fail;
483: }
484: /* open shared pkcs11-libarary */
485: if ((handle = dlopen(provider_id, RTLD_NOW)) == NULL) {
486: error("dlopen %s failed: %s", provider_id, dlerror());
487: goto fail;
488: }
489: if ((getfunctionlist = dlsym(handle, "C_GetFunctionList")) == NULL) {
490: error("dlsym(C_GetFunctionList) failed: %s", dlerror());
491: goto fail;
492: }
493: p = xcalloc(1, sizeof(*p));
494: p->name = xstrdup(provider_id);
495: p->handle = handle;
496: /* setup the pkcs11 callbacks */
497: if ((rv = (*getfunctionlist)(&f)) != CKR_OK) {
498: error("C_GetFunctionList failed: %lu", rv);
499: goto fail;
500: }
501: p->function_list = f;
502: if ((rv = f->C_Initialize(NULL)) != CKR_OK) {
503: error("C_Initialize failed: %lu", rv);
504: goto fail;
505: }
506: need_finalize = 1;
507: if ((rv = f->C_GetInfo(&p->info)) != CKR_OK) {
508: error("C_GetInfo failed: %lu", rv);
509: goto fail;
510: }
511: rmspace(p->info.manufacturerID, sizeof(p->info.manufacturerID));
512: rmspace(p->info.libraryDescription, sizeof(p->info.libraryDescription));
513: debug("manufacturerID <%s> cryptokiVersion %d.%d"
514: " libraryDescription <%s> libraryVersion %d.%d",
515: p->info.manufacturerID,
516: p->info.cryptokiVersion.major,
517: p->info.cryptokiVersion.minor,
518: p->info.libraryDescription,
519: p->info.libraryVersion.major,
520: p->info.libraryVersion.minor);
521: if ((rv = f->C_GetSlotList(CK_TRUE, NULL, &p->nslots)) != CKR_OK) {
522: error("C_GetSlotList failed: %lu", rv);
523: goto fail;
524: }
525: if (p->nslots == 0) {
526: error("no slots");
527: goto fail;
528: }
529: p->slotlist = xcalloc(p->nslots, sizeof(CK_SLOT_ID));
530: if ((rv = f->C_GetSlotList(CK_TRUE, p->slotlist, &p->nslots))
531: != CKR_OK) {
532: error("C_GetSlotList failed: %lu", rv);
533: goto fail;
534: }
535: p->slotinfo = xcalloc(p->nslots, sizeof(struct pkcs11_slotinfo));
536: p->valid = 1;
537: nkeys = 0;
538: for (i = 0; i < p->nslots; i++) {
539: token = &p->slotinfo[i].token;
540: if ((rv = f->C_GetTokenInfo(p->slotlist[i], token))
541: != CKR_OK) {
542: error("C_GetTokenInfo failed: %lu", rv);
543: continue;
544: }
545: rmspace(token->label, sizeof(token->label));
546: rmspace(token->manufacturerID, sizeof(token->manufacturerID));
547: rmspace(token->model, sizeof(token->model));
548: rmspace(token->serialNumber, sizeof(token->serialNumber));
549: debug("label <%s> manufacturerID <%s> model <%s> serial <%s>"
550: " flags 0x%lx",
551: token->label, token->manufacturerID, token->model,
552: token->serialNumber, token->flags);
553: /* open session, login with pin and retrieve public keys */
554: if (pkcs11_open_session(p, i, pin) == 0)
555: pkcs11_fetch_keys(p, i, keyp, &nkeys);
556: }
557: if (nkeys > 0) {
558: TAILQ_INSERT_TAIL(&pkcs11_providers, p, next);
559: p->refcount++; /* add to provider list */
560: return (nkeys);
561: }
562: error("no keys");
563: /* don't add the provider, since it does not have any keys */
564: fail:
565: if (need_finalize && (rv = f->C_Finalize(NULL)) != CKR_OK)
566: error("C_Finalize failed: %lu", rv);
567: if (p) {
568: if (p->slotlist)
569: xfree(p->slotlist);
570: if (p->slotinfo)
571: xfree(p->slotinfo);
572: xfree(p);
573: }
574: if (handle)
575: dlclose(handle);
576: return (-1);
577: }
1.2 markus 578: #else
579: int
580: pkcs11_add_provider(char *provider_id, char *pin, Key ***keyp)
581: {
582: error("dlopen() not supported");
583: return (-1);
584: }
585: #endif
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