Annotation of src/usr.bin/snmp/usm.c, Revision 1.4.2.1
1.4.2.1 ! tb 1: /* $OpenBSD: usm.c,v 1.4 2019/09/18 09:59:05 martijn Exp $ */
1.1 martijn 2:
3: /*
4: * Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org>
5: *
6: * Permission to use, copy, modify, and distribute this software for any
7: * purpose with or without fee is hereby granted, provided that the above
8: * copyright notice and this permission notice appear in all copies.
9: *
10: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17: */
18:
19: #include <sys/time.h>
20:
21: #include <openssl/evp.h>
22: #include <openssl/hmac.h>
23:
24: #include <ber.h>
25: #include <errno.h>
26: #include <string.h>
27: #include <time.h>
28:
29: #include "smi.h"
30: #include "snmp.h"
31: #include "usm.h"
32:
33: #define USM_MAX_DIGESTLEN 48
34: #define USM_MAX_TIMEWINDOW 150
35: #define USM_SALTOFFSET 8
36:
37: struct usm_sec {
38: struct snmp_sec snmp;
39: char *user;
40: size_t userlen;
41: int engineidset;
42: char *engineid;
43: size_t engineidlen;
1.2 martijn 44: enum usm_key_level authlevel;
45: const EVP_MD *digest;
46: char *authkey;
1.3 martijn 47: enum usm_key_level privlevel;
48: const EVP_CIPHER *cipher;
49: char *privkey;
1.1 martijn 50: int bootsset;
51: uint32_t boots;
52: int timeset;
53: uint32_t time;
54: struct timespec timecheck;
55: };
56:
1.2 martijn 57: struct usm_cookie {
58: size_t digestoffset;
1.3 martijn 59: long long salt;
60: uint32_t boots;
61: uint32_t time;
1.2 martijn 62: };
63:
1.1 martijn 64: static int usm_doinit(struct snmp_agent *);
1.2 martijn 65: static char *usm_genparams(struct snmp_agent *, size_t *, void **);
66: static int usm_finalparams(struct snmp_agent *, char *, size_t, size_t, void *);
1.3 martijn 67: static struct ber_element *usm_encpdu(struct snmp_agent *agent,
68: struct ber_element *pdu, void *cookie);
69: static char *usm_crypt(const EVP_CIPHER *, int, char *, struct usm_cookie *,
70: char *, size_t, size_t *);
1.1 martijn 71: static int usm_parseparams(struct snmp_agent *, char *, size_t, off_t, char *,
1.3 martijn 72: size_t, uint8_t, void **);
73: struct ber_element *usm_decpdu(struct snmp_agent *, char *, size_t, void *);
1.2 martijn 74: static void usm_digest_pos(void *, size_t);
1.1 martijn 75: static void usm_free(void *);
1.2 martijn 76: static char *usm_passwd2mkey(const EVP_MD *, const char *);
77: static char *usm_mkey2lkey(struct usm_sec *, const EVP_MD *, const char *);
78: static size_t usm_digestlen(const EVP_MD *);
1.1 martijn 79:
80: struct snmp_sec *
81: usm_init(const char *user, size_t userlen)
82: {
83: struct snmp_sec *sec;
84: struct usm_sec *usm;
85:
86: if (user == NULL || user[0] == '\0') {
87: errno = EINVAL;
88: return NULL;
89: }
90:
91: if ((sec = malloc(sizeof(*sec))) == NULL)
92: return NULL;
93:
94: if ((usm = calloc(1, sizeof(struct usm_sec))) == NULL) {
95: free(sec);
96: return NULL;
97: }
98: if ((usm->user = malloc(userlen)) == NULL) {
99: free(sec);
100: free(usm);
101: return NULL;
102: }
103: memcpy(usm->user, user, userlen);
104: usm->userlen = userlen;
105:
106: sec->model = SNMP_SEC_USM;
107: sec->init = usm_doinit;
108: sec->genparams = usm_genparams;
1.3 martijn 109: sec->encpdu = usm_encpdu;
1.1 martijn 110: sec->parseparams = usm_parseparams;
1.3 martijn 111: sec->decpdu = usm_decpdu;
1.2 martijn 112: sec->finalparams = usm_finalparams;
1.1 martijn 113: sec->free = usm_free;
1.2 martijn 114: sec->freecookie = free;
1.1 martijn 115: sec->data = usm;
116: return sec;
117: }
118:
119: static int
120: usm_doinit(struct snmp_agent *agent)
121: {
122: struct ber_element *ber;
123: struct usm_sec *usm = agent->v3->sec->data;
124: int level;
125: size_t userlen;
126:
127: if (usm->engineidset && usm->bootsset && usm->timeset)
128: return 0;
129:
130: level = agent->v3->level;
131: agent->v3->level = SNMP_MSGFLAG_REPORT;
132: userlen = usm->userlen;
133: usm->userlen = 0;
134:
135: if ((ber = snmp_get(agent, NULL, 0)) == NULL) {
136: agent->v3->level = level;
137: usm->userlen = userlen;
138: return -1;
139: }
1.4.2.1 ! tb 140: ober_free_element(ber);
1.1 martijn 141:
142: agent->v3->level = level;
143: usm->userlen = userlen;
144:
1.4 martijn 145: /*
146: * Ugly hack for HP Laserjet:
147: * This device returns the engineid on probing, but only returns boots
148: * and time after a packet has been sent with full auth/enc.
149: */
150: if (!usm->engineidset || !usm->bootsset || !usm->timeset) {
151: if ((ber = snmp_get(agent, NULL, 0)) == NULL)
152: return -1;
1.4.2.1 ! tb 153: ober_free_element(ber);
1.4 martijn 154: }
1.1 martijn 155: return 0;
156: }
157:
158: static char *
1.2 martijn 159: usm_genparams(struct snmp_agent *agent, size_t *len, void **cookie)
1.1 martijn 160: {
161: struct ber ber;
1.2 martijn 162: struct ber_element *params, *digestelm;
1.1 martijn 163: struct usm_sec *usm = agent->v3->sec->data;
1.2 martijn 164: char digest[USM_MAX_DIGESTLEN];
1.3 martijn 165: size_t digestlen = 0, saltlen = 0;
1.1 martijn 166: char *secparams = NULL;
167: ssize_t berlen = 0;
1.2 martijn 168: struct usm_cookie *usmcookie;
1.1 martijn 169: struct timespec now, timediff;
170:
1.2 martijn 171: bzero(digest, sizeof(digest));
172:
173: if ((usmcookie = calloc(1, sizeof(*usmcookie))) == NULL)
174: return NULL;
175: *cookie = usmcookie;
176:
1.3 martijn 177: arc4random_buf(&(usmcookie->salt), sizeof(usmcookie->salt));
1.1 martijn 178: if (usm->timeset) {
1.2 martijn 179: if (clock_gettime(CLOCK_MONOTONIC, &now) == -1) {
180: free(usmcookie);
1.1 martijn 181: return NULL;
1.2 martijn 182: }
1.1 martijn 183: timespecsub(&now, &(usm->timecheck), &timediff);
1.3 martijn 184: usmcookie->time = usm->time + timediff.tv_sec;
1.1 martijn 185: } else
1.3 martijn 186: usmcookie->time = 0;
187: usmcookie->boots = usm->boots;
188:
1.2 martijn 189: if (agent->v3->level & SNMP_MSGFLAG_AUTH)
190: digestlen = usm_digestlen(usm->digest);
1.3 martijn 191: if (agent->v3->level & SNMP_MSGFLAG_PRIV)
192: saltlen = sizeof(usmcookie->salt);
193:
1.4.2.1 ! tb 194: if ((params = ober_printf_elements(NULL, "{xddxxx}", usm->engineid,
1.3 martijn 195: usm->engineidlen, usmcookie->boots, usmcookie->time, usm->user,
196: usm->userlen, digest, digestlen, &(usmcookie->salt),
197: saltlen)) == NULL) {
1.2 martijn 198: free(usmcookie);
199: return NULL;
200: }
1.1 martijn 201:
1.4.2.1 ! tb 202: if (ober_scanf_elements(params, "{SSSSe", &digestelm) == -1) {
! 203: ober_free_element(params);
1.2 martijn 204: free(usmcookie);
1.1 martijn 205: return NULL;
1.2 martijn 206: }
207:
1.4.2.1 ! tb 208: ober_set_writecallback(digestelm, usm_digest_pos, usmcookie);
1.1 martijn 209:
210: bzero(&ber, sizeof(ber));
1.4.2.1 ! tb 211: ober_set_application(&ber, smi_application);
! 212: if (ober_write_elements(&ber, params) != -1)
1.1 martijn 213: berlen = ber_copy_writebuf(&ber, (void **)&secparams);
214:
215: *len = berlen;
1.4.2.1 ! tb 216: ober_free_element(params);
! 217: ober_free(&ber);
1.1 martijn 218: return secparams;
219: }
220:
1.3 martijn 221: static struct ber_element *
222: usm_encpdu(struct snmp_agent *agent, struct ber_element *pdu, void *cookie)
223: {
224: struct usm_sec *usm = agent->v3->sec->data;
225: struct usm_cookie *usmcookie = cookie;
226: struct ber ber;
227: struct ber_element *retpdu;
228: char *serialpdu, *encpdu;
229: ssize_t pdulen;
230: size_t encpdulen;
231:
232: bzero(&ber, sizeof(ber));
1.4.2.1 ! tb 233: ober_set_application(&ber, smi_application);
! 234: pdulen = ober_write_elements(&ber, pdu);
1.3 martijn 235: if (pdulen == -1)
236: return NULL;
237:
1.4.2.1 ! tb 238: ober_get_writebuf(&ber, (void **)&serialpdu);
1.3 martijn 239:
240: encpdu = usm_crypt(usm->cipher, 1, usm->privkey, usmcookie, serialpdu,
241: pdulen, &encpdulen);
1.4.2.1 ! tb 242: ober_free(&ber);
1.3 martijn 243: if (encpdu == NULL)
244: return NULL;
245:
1.4.2.1 ! tb 246: retpdu = ober_add_nstring(NULL, encpdu, encpdulen);
1.3 martijn 247: free(encpdu);
248: return retpdu;
249: }
250:
251: static char *
252: usm_crypt(const EVP_CIPHER *cipher, int do_enc, char *key,
253: struct usm_cookie *cookie, char *serialpdu, size_t pdulen, size_t *outlen)
254: {
255: EVP_CIPHER_CTX ctx;
256: size_t i;
257: char iv[EVP_MAX_IV_LENGTH];
258: char *salt = (char *)&(cookie->salt);
259: char *outtext;
260: int len, len2, bs;
261: uint32_t ivv;
262:
263: switch (EVP_CIPHER_type(cipher)) {
264: case NID_des_cbc:
265: /* RFC3414, chap 8.1.1.1. */
266: for (i = 0; i < 8; i++)
267: iv[i] = salt[i] ^ key[USM_SALTOFFSET + i];
268: break;
269: case NID_aes_128_cfb128:
270: /* RFC3826, chap 3.1.2.1. */
271: ivv = htobe32(cookie->boots);
272: memcpy(iv, &ivv, sizeof(ivv));
273: ivv = htobe32(cookie->time);
274: memcpy(iv + sizeof(ivv), &ivv, sizeof(ivv));
275: memcpy(iv + 2 * sizeof(ivv), &(cookie->salt),
276: sizeof(cookie->salt));
277: break;
278: default:
279: return NULL;
280: }
281:
282: bzero(&ctx, sizeof(ctx));
283: if (!EVP_CipherInit(&ctx, cipher, key, iv, do_enc))
284: return NULL;
285:
286: EVP_CIPHER_CTX_set_padding(&ctx, do_enc);
287:
288: bs = EVP_CIPHER_block_size(cipher);
289: /* Maximum output size */
290: *outlen = pdulen + (bs - (pdulen % bs));
291:
292: if ((outtext = malloc(*outlen)) == NULL)
293: return NULL;
294:
295: if (EVP_CipherUpdate(&ctx, outtext, &len, serialpdu, pdulen) &&
296: EVP_CipherFinal_ex(&ctx, outtext + len, &len2))
297: *outlen = len + len2;
298: else {
299: free(outtext);
300: outtext = NULL;
301: }
302:
303: EVP_CIPHER_CTX_cleanup(&ctx);
304:
305: return outtext;
306: }
307:
1.1 martijn 308: static int
1.2 martijn 309: usm_finalparams(struct snmp_agent *agent, char *buf, size_t buflen,
310: size_t secparamsoffset, void *cookie)
311: {
312: struct usm_sec *usm = agent->v3->sec->data;
313: struct usm_cookie *usmcookie = cookie;
314: u_char digest[EVP_MAX_MD_SIZE];
315:
316: if ((agent->v3->level & SNMP_MSGFLAG_AUTH) == 0)
317: return 0;
318:
319: if (usm->authlevel != USM_KEY_LOCALIZED)
320: return -1;
321:
322: if (HMAC(usm->digest, usm->authkey, EVP_MD_size(usm->digest), buf,
323: buflen, digest, NULL) == NULL)
324: return -1;
325:
326: memcpy(buf + secparamsoffset + usmcookie->digestoffset, digest,
327: usm_digestlen(usm->digest));
328: return 0;
329: }
330:
331: static int
1.1 martijn 332: usm_parseparams(struct snmp_agent *agent, char *packet, size_t packetlen,
1.3 martijn 333: off_t secparamsoffset, char *buf, size_t buflen, uint8_t level,
334: void **cookie)
1.1 martijn 335: {
336: struct usm_sec *usm = agent->v3->sec->data;
337: struct ber ber;
338: struct ber_element *secparams;
1.3 martijn 339: char *engineid, *user, *digest, *salt;
340: size_t engineidlen, userlen, digestlen, saltlen;
1.1 martijn 341: struct timespec now, timediff;
1.2 martijn 342: off_t digestoffset;
343: char exp_digest[EVP_MAX_MD_SIZE];
1.3 martijn 344: struct usm_cookie *usmcookie;
1.1 martijn 345:
346: bzero(&ber, sizeof(ber));
1.2 martijn 347: bzero(exp_digest, sizeof(exp_digest));
1.1 martijn 348:
1.4.2.1 ! tb 349: ober_set_application(&ber, smi_application);
! 350: ober_set_readbuf(&ber, buf, buflen);
! 351: if ((secparams = ober_read_elements(&ber, NULL)) == NULL)
1.1 martijn 352: return -1;
1.4.2.1 ! tb 353: ober_free(&ber);
1.1 martijn 354:
1.3 martijn 355: if ((usmcookie = malloc(sizeof(*usmcookie))) == NULL)
356: goto fail;
357: *cookie = usmcookie;
358:
1.4.2.1 ! tb 359: if (ober_scanf_elements(secparams, "{xddxpxx}", &engineid, &engineidlen,
1.3 martijn 360: &(usmcookie->boots), &(usmcookie->time), &user, &userlen,
361: &digestoffset, &digest, &digestlen, &salt, &saltlen) == -1)
362: goto fail;
363: if (saltlen != sizeof(usmcookie->salt) && saltlen != 0)
1.1 martijn 364: goto fail;
1.3 martijn 365: memcpy(&(usmcookie->salt), salt, saltlen);
1.1 martijn 366:
367: if (!usm->engineidset) {
368: if (usm_setengineid(agent->v3->sec, engineid,
369: engineidlen) == -1)
370: goto fail;
371: } else {
372: if (usm->engineidlen != engineidlen)
373: goto fail;
374: if (memcmp(usm->engineid, engineid, engineidlen) != 0)
375: goto fail;
376: }
377:
378: if (!usm->bootsset) {
1.3 martijn 379: usm->boots = usmcookie->boots;
1.1 martijn 380: usm->bootsset = 1;
381: } else {
1.3 martijn 382: if (usmcookie->boots < usm->boots)
1.1 martijn 383: goto fail;
1.3 martijn 384: if (usmcookie->boots > usm->boots) {
1.1 martijn 385: usm->bootsset = 0;
386: usm->timeset = 0;
387: usm_doinit(agent);
388: goto fail;
389: }
390: }
391:
392: if (!usm->timeset) {
1.3 martijn 393: usm->time = usmcookie->time;
1.1 martijn 394: if (clock_gettime(CLOCK_MONOTONIC, &usm->timecheck) == -1)
395: goto fail;
396: usm->timeset = 1;
397: } else {
398: if (clock_gettime(CLOCK_MONOTONIC, &now) == -1)
399: goto fail;
400: timespecsub(&now, &(usm->timecheck), &timediff);
1.3 martijn 401: if (usmcookie->time <
402: usm->time + timediff.tv_sec - USM_MAX_TIMEWINDOW ||
403: usmcookie->time >
404: usm->time + timediff.tv_sec + USM_MAX_TIMEWINDOW) {
1.1 martijn 405: usm->bootsset = 0;
406: usm->timeset = 0;
407: usm_doinit(agent);
408: goto fail;
409: }
1.4 martijn 410: }
411: /*
412: * Don't assume these are set if both are zero.
413: * Ugly hack for HP Laserjet
414: */
415: if (usm->boots == 0 && usm->time == 0) {
416: usm->bootsset = 0;
417: usm->timeset = 0;
1.1 martijn 418: }
419:
420: if (userlen != usm->userlen ||
421: memcmp(user, usm->user, userlen) != 0)
422: goto fail;
423:
1.2 martijn 424: if (level & SNMP_MSGFLAG_AUTH) {
425: if (digestlen != usm_digestlen(usm->digest))
426: goto fail;
427: }
428: if ((agent->v3->level & SNMP_MSGFLAG_AUTH)) {
429: bzero(packet + secparamsoffset + digestoffset, digestlen);
430: if (HMAC(usm->digest, usm->authkey, EVP_MD_size(usm->digest), packet,
431: packetlen, exp_digest, NULL) == NULL)
432: goto fail;
433:
434: if (memcmp(exp_digest, digest, digestlen) != 0)
435: goto fail;
436: } else
437: if (digestlen != 0)
438: goto fail;
439:
1.4.2.1 ! tb 440: ober_free_element(secparams);
1.1 martijn 441: return 0;
442:
443: fail:
1.3 martijn 444: free(usmcookie);
1.4.2.1 ! tb 445: ober_free_element(secparams);
1.1 martijn 446: return -1;
447: }
448:
1.3 martijn 449: struct ber_element *
450: usm_decpdu(struct snmp_agent *agent, char *encpdu, size_t encpdulen, void *cookie)
451: {
452: struct usm_sec *usm = agent->v3->sec->data;
453: struct usm_cookie *usmcookie = cookie;
454: struct ber ber;
455: struct ber_element *scopedpdu;
456: char *rawpdu;
457: size_t rawpdulen;
458:
459: if ((rawpdu = usm_crypt(usm->cipher, 0, usm->privkey, usmcookie,
460: encpdu, encpdulen, &rawpdulen)) == NULL)
461: return NULL;
462:
463: bzero(&ber, sizeof(ber));
1.4.2.1 ! tb 464: ober_set_application(&ber, smi_application);
! 465: ober_set_readbuf(&ber, rawpdu, rawpdulen);
! 466: scopedpdu = ober_read_elements(&ber, NULL);
! 467: ober_free(&ber);
1.3 martijn 468: free(rawpdu);
469:
470: return scopedpdu;
471: }
472:
1.1 martijn 473: static void
1.2 martijn 474: usm_digest_pos(void *data, size_t offset)
475: {
476: struct usm_cookie *usmcookie = data;
477:
478: usmcookie->digestoffset = offset;
479: }
480:
481: static void
1.1 martijn 482: usm_free(void *data)
483: {
484: struct usm_sec *usm = data;
485:
486: free(usm->user);
1.2 martijn 487: free(usm->authkey);
1.3 martijn 488: free(usm->privkey);
1.1 martijn 489: free(usm->engineid);
490: free(usm);
491: }
492:
493: int
1.2 martijn 494: usm_setauth(struct snmp_sec *sec, const EVP_MD *digest, const char *key,
495: size_t keylen, enum usm_key_level level)
496: {
497: struct usm_sec *usm = sec->data;
498: char *lkey;
499:
500: /*
501: * We could transform a master key to a local key here if we already
502: * have usm_setengineid called. Sine snmpc.c is the only caller at
503: * the moment there's no need, since it always calls this function
504: * first.
505: */
506: if (level == USM_KEY_PASSWORD) {
507: if ((usm->authkey = usm_passwd2mkey(digest, key)) == NULL)
508: return -1;
509: level = USM_KEY_MASTER;
510: keylen = EVP_MD_size(digest);
511: } else {
512: if (keylen != (size_t)EVP_MD_size(digest)) {
513: errno = EINVAL;
514: return -1;
515: }
516: if ((lkey = malloc(keylen)) == NULL)
517: return -1;
518: memcpy(lkey, key, keylen);
519: usm->authkey = lkey;
520: }
521: usm->digest = digest;
522: usm->authlevel = level;
523: return 0;
524: }
525:
526: int
1.3 martijn 527: usm_setpriv(struct snmp_sec *sec, const EVP_CIPHER *cipher, const char *key,
528: size_t keylen, enum usm_key_level level)
529: {
530: struct usm_sec *usm = sec->data;
531: char *lkey;
532:
533: if (usm->digest == NULL) {
534: errno = EINVAL;
535: return -1;
536: }
537:
538: /*
539: * We could transform a master key to a local key here if we already
540: * have usm_setengineid called. Sine snmpc.c is the only caller at
541: * the moment there's no need, since it always calls us first.
542: */
543: if (level == USM_KEY_PASSWORD) {
544: if ((usm->privkey = usm_passwd2mkey(usm->digest, key)) == NULL)
545: return -1;
546: level = USM_KEY_MASTER;
547: keylen = EVP_MD_size(usm->digest);
548: } else {
549: if (keylen != (size_t)EVP_MD_size(usm->digest)) {
550: errno = EINVAL;
551: return -1;
552: }
553: if ((lkey = malloc(keylen)) == NULL)
554: return -1;
555: memcpy(lkey, key, keylen);
556: usm->privkey = lkey;
557: }
558: usm->cipher = cipher;
559: usm->privlevel = level;
560: return 0;
561: }
562:
563: int
1.1 martijn 564: usm_setengineid(struct snmp_sec *sec, char *engineid, size_t engineidlen)
565: {
566: struct usm_sec *usm = sec->data;
1.2 martijn 567: char *mkey;
1.1 martijn 568:
569: if (usm->engineid != NULL)
570: free(usm->engineid);
571: if ((usm->engineid = malloc(engineidlen)) == NULL)
572: return -1;
573: memcpy(usm->engineid, engineid, engineidlen);
574: usm->engineidlen = engineidlen;
575: usm->engineidset = 1;
576:
1.2 martijn 577: if (usm->authlevel == USM_KEY_MASTER) {
578: mkey = usm->authkey;
579: if ((usm->authkey = usm_mkey2lkey(usm, usm->digest,
580: mkey)) == NULL) {
581: usm->authkey = mkey;
582: return -1;
583: }
584: free(mkey);
585: usm->authlevel = USM_KEY_LOCALIZED;
1.3 martijn 586: }
587: if (usm->privlevel == USM_KEY_MASTER) {
588: mkey = usm->privkey;
589: if ((usm->privkey = usm_mkey2lkey(usm, usm->digest,
590: mkey)) == NULL) {
591: usm->privkey = mkey;
592: return -1;
593: }
594: free(mkey);
595: usm->privlevel = USM_KEY_LOCALIZED;
1.2 martijn 596: }
597:
1.1 martijn 598: return 0;
599: }
600:
601: int
602: usm_setbootstime(struct snmp_sec *sec, uint32_t boots, uint32_t time)
603: {
604: struct usm_sec *usm = sec->data;
605:
606: if (clock_gettime(CLOCK_MONOTONIC, &(usm->timecheck)) == -1)
607: return -1;
608:
609: usm->boots = boots;
610: usm->bootsset = 1;
611: usm->time = time;
612: usm->timeset = 1;
613: return 0;
1.2 martijn 614: }
615:
616: static char *
617: usm_passwd2mkey(const EVP_MD *md, const char *passwd)
618: {
619: EVP_MD_CTX ctx;
620: int i, count;
621: const u_char *pw;
622: u_char *c;
623: u_char keybuf[EVP_MAX_MD_SIZE];
624: unsigned dlen;
625: char *key;
626:
627: bzero(&ctx, sizeof(ctx));
628: EVP_DigestInit_ex(&ctx, md, NULL);
629: pw = (const u_char *)passwd;
630: for (count = 0; count < 1048576; count += 64) {
631: c = keybuf;
632: for (i = 0; i < 64; i++) {
633: if (*pw == '\0')
634: pw = (const u_char *)passwd;
635: *c++ = *pw++;
636: }
637: EVP_DigestUpdate(&ctx, keybuf, 64);
638: }
639: EVP_DigestFinal_ex(&ctx, keybuf, &dlen);
640: EVP_MD_CTX_cleanup(&ctx);
641:
642: if ((key = malloc(dlen)) == NULL)
643: return NULL;
644: memcpy(key, keybuf, dlen);
645: return key;
646: }
647:
648: static char *
649: usm_mkey2lkey(struct usm_sec *usm, const EVP_MD *md, const char *mkey)
650: {
651: EVP_MD_CTX ctx;
652: u_char buf[EVP_MAX_MD_SIZE];
653: u_char *lkey;
654: unsigned lklen;
655:
656: bzero(&ctx, sizeof(ctx));
657: EVP_DigestInit_ex(&ctx, md, NULL);
658:
659: EVP_DigestUpdate(&ctx, mkey, EVP_MD_size(md));
660: EVP_DigestUpdate(&ctx, usm->engineid, usm->engineidlen);
661: EVP_DigestUpdate(&ctx, mkey, EVP_MD_size(md));
662:
663: EVP_DigestFinal_ex(&ctx, buf, &lklen);
664: EVP_MD_CTX_cleanup(&ctx);
665:
666: if ((lkey = malloc(lklen)) == NULL)
667: return NULL;
668: memcpy(lkey, buf, lklen);
669: return lkey;
670: }
671:
672: static size_t
673: usm_digestlen(const EVP_MD *md)
674: {
675: switch (EVP_MD_type(md)) {
676: case NID_md5:
677: case NID_sha1:
678: return 12;
679: case NID_sha224:
680: return 16;
681: case NID_sha256:
682: return 24;
683: case NID_sha384:
684: return 32;
685: case NID_sha512:
686: return 48;
687: default:
688: return 0;
689: }
1.1 martijn 690: }
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