Annotation of src/usr.bin/ssh/ssh-pkcs11.c, Revision 1.2
1.1 markus 1: /*
2: * Copyright (c) 2010 Markus Friedl. All rights reserved.
3: *
4: * Permission to use, copy, modify, and distribute this software for any
5: * purpose with or without fee is hereby granted, provided that the above
6: * copyright notice and this permission notice appear in all copies.
7: *
8: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15: */
16:
17: #include <sys/types.h>
18: #include <sys/queue.h>
19: #include <stdarg.h>
20: #include <stdio.h>
21:
22: #include <string.h>
23: #include <dlfcn.h>
24:
25: #define CRYPTOKI_COMPAT
26: #include "pkcs11.h"
27:
28: #include "log.h"
29: #include "misc.h"
30: #include "key.h"
31: #include "ssh-pkcs11.h"
32: #include "xmalloc.h"
33:
34: struct pkcs11_slotinfo {
35: CK_TOKEN_INFO token;
36: CK_SESSION_HANDLE session;
37: int logged_in;
38: };
39:
40: struct pkcs11_provider {
41: char *name;
42: void *handle;
43: CK_FUNCTION_LIST *function_list;
44: CK_INFO info;
45: CK_ULONG nslots;
46: CK_SLOT_ID *slotlist;
47: struct pkcs11_slotinfo *slotinfo;
48: int valid;
49: int refcount;
50: TAILQ_ENTRY(pkcs11_provider) next;
51: };
52:
53: TAILQ_HEAD(, pkcs11_provider) pkcs11_providers;
54:
55: struct pkcs11_key {
56: struct pkcs11_provider *provider;
57: CK_ULONG slotidx;
58: int (*orig_finish)(RSA *rsa);
59: RSA_METHOD rsa_method;
60: char *keyid;
61: int keyid_len;
62: };
63:
64: int pkcs11_interactive = 0;
65:
66: int
67: pkcs11_init(int interactive)
68: {
69: pkcs11_interactive = interactive;
70: TAILQ_INIT(&pkcs11_providers);
71: return (0);
72: }
73:
74: /*
75: * finalize a provider shared libarary, it's no longer usable.
76: * however, there might still be keys referencing this provider,
77: * so the actuall freeing of memory is handled by pkcs11_provider_unref().
78: * this is called when a provider gets unregistered.
79: */
80: static void
81: pkcs11_provider_finalize(struct pkcs11_provider *p)
82: {
83: CK_RV rv;
84: CK_ULONG i;
85:
86: debug("pkcs11_provider_finalize: %p refcount %d valid %d",
87: p, p->refcount, p->valid);
88: if (!p->valid)
89: return;
90: for (i = 0; i < p->nslots; i++) {
91: if (p->slotinfo[i].session &&
92: (rv = p->function_list->C_CloseSession(
93: p->slotinfo[i].session)) != CKR_OK)
94: error("C_CloseSession failed: %lu", rv);
95: }
96: if ((rv = p->function_list->C_Finalize(NULL)) != CKR_OK)
97: error("C_Finalize failed: %lu", rv);
98: p->valid = 0;
99: p->function_list = NULL;
100: dlclose(p->handle);
101: }
102:
103: /*
104: * remove a reference to the provider.
105: * called when a key gets destroyed or when the provider is unregistered.
106: */
107: static void
108: pkcs11_provider_unref(struct pkcs11_provider *p)
109: {
110: debug("pkcs11_provider_unref: %p refcount %d", p, p->refcount);
111: if (--p->refcount <= 0) {
112: if (p->valid)
113: error("pkcs11_provider_unref: %p still valid", p);
114: xfree(p->slotlist);
115: xfree(p->slotinfo);
116: xfree(p);
117: }
118: }
119:
120: /* unregister all providers, keys might still point to the providers */
121: void
122: pkcs11_terminate(void)
123: {
124: struct pkcs11_provider *p;
125:
126: while ((p = TAILQ_FIRST(&pkcs11_providers)) != NULL) {
127: TAILQ_REMOVE(&pkcs11_providers, p, next);
128: pkcs11_provider_finalize(p);
129: pkcs11_provider_unref(p);
130: }
131: }
132:
133: /* lookup provider by name */
134: static struct pkcs11_provider *
135: pkcs11_provider_lookup(char *provider_id)
136: {
137: struct pkcs11_provider *p;
138:
139: TAILQ_FOREACH(p, &pkcs11_providers, next) {
140: debug("check %p %s", p, p->name);
141: if (!strcmp(provider_id, p->name))
142: return (p);
143: }
144: return (NULL);
145: }
146:
147: /* unregister provider by name */
148: int
149: pkcs11_del_provider(char *provider_id)
150: {
151: struct pkcs11_provider *p;
152:
153: if ((p = pkcs11_provider_lookup(provider_id)) != NULL) {
154: TAILQ_REMOVE(&pkcs11_providers, p, next);
155: pkcs11_provider_finalize(p);
156: pkcs11_provider_unref(p);
157: return (0);
158: }
159: return (-1);
160: }
161:
162: /* openssl callback for freeing an RSA key */
163: static int
164: pkcs11_rsa_finish(RSA *rsa)
165: {
166: struct pkcs11_key *k11;
167: int rv = -1;
168:
169: if ((k11 = RSA_get_app_data(rsa)) != NULL) {
170: if (k11->orig_finish)
171: rv = k11->orig_finish(rsa);
172: if (k11->provider)
173: pkcs11_provider_unref(k11->provider);
174: if (k11->keyid)
175: xfree(k11->keyid);
176: xfree(k11);
177: }
178: return (rv);
179: }
180:
181: /* openssl callback doing the actual signing operation */
182: static int
183: pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
184: int padding)
185: {
186: struct pkcs11_key *k11;
187: struct pkcs11_slotinfo *si;
188: CK_FUNCTION_LIST *f;
189: CK_OBJECT_HANDLE obj;
190: CK_ULONG tlen = 0, nfound = 0;
191: CK_RV rv;
192: CK_OBJECT_CLASS private_key_class = CKO_PRIVATE_KEY;
193: CK_BBOOL true = CK_TRUE;
194: CK_MECHANISM mech = {
195: CKM_RSA_PKCS, NULL_PTR, 0
196: };
197: CK_ATTRIBUTE key_filter[] = {
198: {CKA_CLASS, &private_key_class, sizeof(private_key_class) },
199: {CKA_ID, NULL, 0},
200: {CKA_SIGN, &true, sizeof(true) }
201: };
202: char *pin, prompt[1024];
203: int rval = -1;
204:
205: if ((k11 = RSA_get_app_data(rsa)) == NULL) {
206: error("RSA_get_app_data failed for rsa %p", rsa);
207: return (-1);
208: }
209: if (!k11->provider || !k11->provider->valid) {
210: error("no pkcs11 (valid) provider for rsa %p", rsa);
211: return (-1);
212: }
213: f = k11->provider->function_list;
214: si = &k11->provider->slotinfo[k11->slotidx];
215: if ((si->token.flags & CKF_LOGIN_REQUIRED) && !si->logged_in) {
216: if (!pkcs11_interactive) {
217: error("need pin");
218: return (-1);
219: }
220: snprintf(prompt, sizeof(prompt), "Enter PIN for '%s': ",
221: si->token.label);
222: pin = read_passphrase(prompt, RP_ALLOW_EOF);
223: if (pin == NULL)
224: return (-1); /* bail out */
225: if ((rv = f->C_Login(si->session, CKU_USER, pin, strlen(pin)))
226: != CKR_OK) {
227: xfree(pin);
228: error("C_Login failed: %lu", rv);
229: return (-1);
230: }
231: xfree(pin);
232: si->logged_in = 1;
233: }
234: key_filter[1].pValue = k11->keyid;
235: key_filter[1].ulValueLen = k11->keyid_len;
236: if ((rv = f->C_FindObjectsInit(si->session, key_filter, 3)) != CKR_OK) {
237: error("C_FindObjectsInit failed: %lu", rv);
238: return (-1);
239: }
240: if ((rv = f->C_FindObjects(si->session, &obj, 1, &nfound)) != CKR_OK ||
241: nfound != 1) {
242: error("C_FindObjects failed (%lu nfound): %lu", nfound, rv);
243: } else if ((rv = f->C_SignInit(si->session, &mech, obj)) != CKR_OK) {
244: error("C_SignInit failed: %lu", rv);
245: } else {
246: /* XXX handle CKR_BUFFER_TOO_SMALL */
247: tlen = RSA_size(rsa);
248: rv = f->C_Sign(si->session, (CK_BYTE *)from, flen, to, &tlen);
249: if (rv == CKR_OK)
250: rval = tlen;
251: else
252: error("C_Sign failed: %lu", rv);
253: }
254: if ((rv = f->C_FindObjectsFinal(si->session)) != CKR_OK)
255: error("C_FindObjectsFinal failed: %lu", rv);
256: return (rval);
257: }
258:
259: static int
260: pkcs11_rsa_private_decrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
261: int padding)
262: {
263: return (-1);
264: }
265:
266: /* redirect private key operations for rsa key to pkcs11 token */
267: static int
268: pkcs11_rsa_wrap(struct pkcs11_provider *provider, CK_ULONG slotidx,
269: CK_ATTRIBUTE *keyid_attrib, RSA *rsa)
270: {
271: struct pkcs11_key *k11;
272: const RSA_METHOD *def = RSA_get_default_method();
273:
274: k11 = xcalloc(1, sizeof(*k11));
275: k11->provider = provider;
276: provider->refcount++; /* provider referenced by RSA key */
277: k11->slotidx = slotidx;
278: /* identify key object on smartcard */
279: k11->keyid_len = keyid_attrib->ulValueLen;
280: k11->keyid = xmalloc(k11->keyid_len);
281: memcpy(k11->keyid, keyid_attrib->pValue, k11->keyid_len);
282: k11->orig_finish = def->finish;
283: memcpy(&k11->rsa_method, def, sizeof(k11->rsa_method));
284: k11->rsa_method.name = "pkcs11";
285: k11->rsa_method.rsa_priv_enc = pkcs11_rsa_private_encrypt;
286: k11->rsa_method.rsa_priv_dec = pkcs11_rsa_private_decrypt;
287: k11->rsa_method.finish = pkcs11_rsa_finish;
288: RSA_set_method(rsa, &k11->rsa_method);
289: RSA_set_app_data(rsa, k11);
290: return (0);
291: }
292:
293: /* remove trailing spaces */
294: static void
295: rmspace(char *buf, size_t len)
296: {
297: size_t i;
298:
299: if (!len)
300: return;
301: for (i = len - 1; i > 0; i--)
302: if (i == len - 1 || buf[i] == ' ')
303: buf[i] = '\0';
304: else
305: break;
306: }
307:
308: /*
309: * open a pkcs11 session and login if required.
310: * if pin == NULL we delay login until key use
311: */
312: static int
313: pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin)
314: {
315: CK_RV rv;
316: CK_FUNCTION_LIST *f;
317: CK_SESSION_HANDLE session;
318: int login_required;
319:
320: f = p->function_list;
321: login_required = p->slotinfo[slotidx].token.flags & CKF_LOGIN_REQUIRED;
322: if (pin && login_required && !strlen(pin)) {
323: error("pin required");
324: return (-1);
325: }
326: if ((rv = f->C_OpenSession(p->slotlist[slotidx], CKF_RW_SESSION|
327: CKF_SERIAL_SESSION, NULL, NULL, &session))
328: != CKR_OK) {
329: error("C_OpenSession failed: %lu", rv);
330: return (-1);
331: }
332: if (login_required && pin) {
333: if ((rv = f->C_Login(session, CKU_USER, pin, strlen(pin)))
334: != CKR_OK) {
335: error("C_Login failed: %lu", rv);
336: if ((rv = f->C_CloseSession(session)) != CKR_OK)
337: error("C_CloseSession failed: %lu", rv);
338: return (-1);
339: }
340: p->slotinfo[slotidx].logged_in = 1;
341: }
342: p->slotinfo[slotidx].session = session;
343: return (0);
344: }
345:
346: /*
347: * lookup public keys for token in slot identified by slotidx,
348: * add 'wrapped' public keys to the 'keysp' array and increment nkeys.
349: * keysp points to an (possibly empty) array with *nkeys keys.
350: */
351: static int
352: pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx, Key ***keysp,
353: int *nkeys)
354: {
355: Key *key;
356: RSA *rsa;
357: int i;
358: CK_RV rv;
359: CK_OBJECT_HANDLE obj;
360: CK_ULONG nfound;
361: CK_SESSION_HANDLE session;
362: CK_FUNCTION_LIST *f;
363: CK_OBJECT_CLASS pubkey_class = CKO_PUBLIC_KEY;
364: CK_ATTRIBUTE pubkey_filter[] = {
365: { CKA_CLASS, &pubkey_class, sizeof(pubkey_class) }
366: };
367: CK_ATTRIBUTE attribs[] = {
368: { CKA_ID, NULL, 0 },
369: { CKA_MODULUS, NULL, 0 },
370: { CKA_PUBLIC_EXPONENT, NULL, 0 }
371: };
372:
373: f = p->function_list;
374: session = p->slotinfo[slotidx].session;
375: /* setup a filter the looks for public keys */
376: if ((rv = f->C_FindObjectsInit(session, pubkey_filter, 1)) != CKR_OK) {
377: error("C_FindObjectsInit failed: %lu", rv);
378: return (-1);
379: }
380: while (1) {
381: /* XXX 3 attributes in attribs[] */
382: for (i = 0; i < 3; i++) {
383: attribs[i].pValue = NULL;
384: attribs[i].ulValueLen = 0;
385: }
386: if ((rv = f->C_FindObjects(session, &obj, 1, &nfound)) != CKR_OK
387: || nfound == 0)
388: break;
389: /* found a key, so figure out size of the attributes */
390: if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
391: != CKR_OK) {
392: error("C_GetAttributeValue failed: %lu", rv);
393: continue;
394: }
395: /* allocate buffers for attributes, XXX check ulValueLen? */
396: for (i = 0; i < 3; i++)
397: attribs[i].pValue = xmalloc(attribs[i].ulValueLen);
398: /* retrieve ID, modulus and public exponent of RSA key */
399: if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
400: != CKR_OK) {
401: error("C_GetAttributeValue failed: %lu", rv);
402: } else if ((rsa = RSA_new()) == NULL) {
403: error("RSA_new failed");
404: } else {
405: rsa->n = BN_bin2bn(attribs[1].pValue,
406: attribs[1].ulValueLen, NULL);
407: rsa->e = BN_bin2bn(attribs[2].pValue,
408: attribs[2].ulValueLen, NULL);
409: if (rsa->n && rsa->e &&
410: pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
411: key = key_new(KEY_UNSPEC);
412: key->rsa = rsa;
413: key->type = KEY_RSA;
414: key->flags |= KEY_FLAG_EXT;
415: /* expand key array and add key */
416: *keysp = xrealloc(*keysp, *nkeys + 1,
417: sizeof(Key *));
418: (*keysp)[*nkeys] = key;
419: *nkeys = *nkeys + 1;
420: debug("have %d keys", *nkeys);
421: } else {
422: RSA_free(rsa);
423: }
424: }
425: for (i = 0; i < 3; i++)
426: xfree(attribs[i].pValue);
427: }
428: if ((rv = f->C_FindObjectsFinal(session)) != CKR_OK)
429: error("C_FindObjectsFinal failed: %lu", rv);
430: return (0);
431: }
432:
1.2 ! markus 433: #ifdef HAVE_DLOPEN
1.1 markus 434: /* register a new provider, fails if provider already exists */
435: int
436: pkcs11_add_provider(char *provider_id, char *pin, Key ***keyp)
437: {
438: int nkeys, need_finalize = 0;
439: struct pkcs11_provider *p = NULL;
440: void *handle = NULL;
441: CK_RV (*getfunctionlist)(CK_FUNCTION_LIST **);
442: CK_RV rv;
443: CK_FUNCTION_LIST *f = NULL;
444: CK_TOKEN_INFO *token;
445: CK_ULONG i;
446:
447: *keyp = NULL;
448: if (pkcs11_provider_lookup(provider_id) != NULL) {
449: error("provider already registered: %s", provider_id);
450: goto fail;
451: }
452: /* open shared pkcs11-libarary */
453: if ((handle = dlopen(provider_id, RTLD_NOW)) == NULL) {
454: error("dlopen %s failed: %s", provider_id, dlerror());
455: goto fail;
456: }
457: if ((getfunctionlist = dlsym(handle, "C_GetFunctionList")) == NULL) {
458: error("dlsym(C_GetFunctionList) failed: %s", dlerror());
459: goto fail;
460: }
461: p = xcalloc(1, sizeof(*p));
462: p->name = xstrdup(provider_id);
463: p->handle = handle;
464: /* setup the pkcs11 callbacks */
465: if ((rv = (*getfunctionlist)(&f)) != CKR_OK) {
466: error("C_GetFunctionList failed: %lu", rv);
467: goto fail;
468: }
469: p->function_list = f;
470: if ((rv = f->C_Initialize(NULL)) != CKR_OK) {
471: error("C_Initialize failed: %lu", rv);
472: goto fail;
473: }
474: need_finalize = 1;
475: if ((rv = f->C_GetInfo(&p->info)) != CKR_OK) {
476: error("C_GetInfo failed: %lu", rv);
477: goto fail;
478: }
479: rmspace(p->info.manufacturerID, sizeof(p->info.manufacturerID));
480: rmspace(p->info.libraryDescription, sizeof(p->info.libraryDescription));
481: debug("manufacturerID <%s> cryptokiVersion %d.%d"
482: " libraryDescription <%s> libraryVersion %d.%d",
483: p->info.manufacturerID,
484: p->info.cryptokiVersion.major,
485: p->info.cryptokiVersion.minor,
486: p->info.libraryDescription,
487: p->info.libraryVersion.major,
488: p->info.libraryVersion.minor);
489: if ((rv = f->C_GetSlotList(CK_TRUE, NULL, &p->nslots)) != CKR_OK) {
490: error("C_GetSlotList failed: %lu", rv);
491: goto fail;
492: }
493: if (p->nslots == 0) {
494: error("no slots");
495: goto fail;
496: }
497: p->slotlist = xcalloc(p->nslots, sizeof(CK_SLOT_ID));
498: if ((rv = f->C_GetSlotList(CK_TRUE, p->slotlist, &p->nslots))
499: != CKR_OK) {
500: error("C_GetSlotList failed: %lu", rv);
501: goto fail;
502: }
503: p->slotinfo = xcalloc(p->nslots, sizeof(struct pkcs11_slotinfo));
504: p->valid = 1;
505: nkeys = 0;
506: for (i = 0; i < p->nslots; i++) {
507: token = &p->slotinfo[i].token;
508: if ((rv = f->C_GetTokenInfo(p->slotlist[i], token))
509: != CKR_OK) {
510: error("C_GetTokenInfo failed: %lu", rv);
511: continue;
512: }
513: rmspace(token->label, sizeof(token->label));
514: rmspace(token->manufacturerID, sizeof(token->manufacturerID));
515: rmspace(token->model, sizeof(token->model));
516: rmspace(token->serialNumber, sizeof(token->serialNumber));
517: debug("label <%s> manufacturerID <%s> model <%s> serial <%s>"
518: " flags 0x%lx",
519: token->label, token->manufacturerID, token->model,
520: token->serialNumber, token->flags);
521: /* open session, login with pin and retrieve public keys */
522: if (pkcs11_open_session(p, i, pin) == 0)
523: pkcs11_fetch_keys(p, i, keyp, &nkeys);
524: }
525: if (nkeys > 0) {
526: TAILQ_INSERT_TAIL(&pkcs11_providers, p, next);
527: p->refcount++; /* add to provider list */
528: return (nkeys);
529: }
530: error("no keys");
531: /* don't add the provider, since it does not have any keys */
532: fail:
533: if (need_finalize && (rv = f->C_Finalize(NULL)) != CKR_OK)
534: error("C_Finalize failed: %lu", rv);
535: if (p) {
536: if (p->slotlist)
537: xfree(p->slotlist);
538: if (p->slotinfo)
539: xfree(p->slotinfo);
540: xfree(p);
541: }
542: if (handle)
543: dlclose(handle);
544: return (-1);
545: }
1.2 ! markus 546: #else
! 547: int
! 548: pkcs11_add_provider(char *provider_id, char *pin, Key ***keyp)
! 549: {
! 550: error("dlopen() not supported");
! 551: return (-1);
! 552: }
! 553: #endif
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