2 * $Id: uams_dhx_pam.c,v 1.21 2002-02-05 20:42:04 srittau Exp $
4 * Copyright (c) 1990,1993 Regents of The University of Michigan.
5 * Copyright (c) 1999 Adrian Sun (asun@u.washington.edu)
6 * All Rights Reserved. See COPYRIGHT.
11 #endif /* HAVE_CONFIG_H */
13 #if defined(USE_PAM) && defined(UAM_DHX)
17 #include <atalk/logger.h>
21 #endif /* HAVE_UNISTD_H */
24 #include <security/pam_appl.h>
27 #include <openssl/bn.h>
28 #include <openssl/dh.h>
29 #include <openssl/cast.h>
30 #else /* OPENSSL_DHX */
34 #endif /* OPENSSL_DHX */
36 #include <atalk/afp.h>
37 #include <atalk/uam.h>
41 #define CRYPTBUFLEN (KEYSIZE*2)
42 #define CRYPT2BUFLEN (KEYSIZE + PASSWDLEN)
43 #define CHANGEPWBUFLEN (KEYSIZE + 2*PASSWDLEN)
45 /* hash a number to a 16-bit quantity */
46 #define dhxhash(a) ((((unsigned long) (a) >> 8) ^ \
47 (unsigned long) (a)) & 0xffff)
50 static CAST_KEY castkey;
51 static struct passwd *dhxpwd;
52 static u_int8_t randbuf[KEYSIZE];
54 /* diffie-hellman bits */
55 static unsigned char msg2_iv[] = "CJalbert";
56 static unsigned char msg3_iv[] = "LWallace";
57 static const u_int8_t p[] = {0xBA, 0x28, 0x73, 0xDF, 0xB0, 0x60, 0x57, 0xD4,
58 0x3F, 0x20, 0x24, 0x74, 0x4C, 0xEE, 0xE7, 0x5B};
59 static const u_int8_t g = 0x07;
62 /* Static variables used to communicate between the conversation function
63 * and the server_login function
65 static pam_handle_t *pamh = NULL;
66 static char *PAM_username;
67 static char *PAM_password;
69 /* PAM conversation function
70 * Here we assume (for now, at least) that echo on means login name, and
71 * echo off means password.
73 static int PAM_conv (int num_msg,
74 const struct pam_message **msg,
75 struct pam_response **resp,
78 struct pam_response *reply;
80 #define COPY_STRING(s) (s) ? strdup(s) : NULL
86 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM DHX Conversation Err -- %s",
92 reply = (struct pam_response *)
93 calloc(num_msg, sizeof(struct pam_response));
97 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM DHX Conversation Err -- %s",
103 for (count = 0; count < num_msg; count++) {
106 switch (msg[count]->msg_style) {
107 case PAM_PROMPT_ECHO_ON:
108 if (!(string = COPY_STRING(PAM_username))) {
110 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: username failure -- %s",
116 case PAM_PROMPT_ECHO_OFF:
117 if (!(string = COPY_STRING(PAM_password))) {
119 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: passwd failure: --: %s",
126 #ifdef PAM_BINARY_PROMPT
127 case PAM_BINARY_PROMPT:
128 #endif /* PAM_BINARY_PROMPT */
134 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Binary_Prompt -- %s",
141 reply[count].resp_retcode = 0;
142 reply[count].resp = string;
149 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM Success -- %s",
155 for (count = 0; count < num_msg; count++) {
156 if (!reply[count].resp)
158 switch (msg[count]->msg_style) {
159 case PAM_PROMPT_ECHO_OFF:
160 case PAM_PROMPT_ECHO_ON:
161 free(reply[count].resp);
167 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM DHX Conversation Err -- %s",
173 static struct pam_conv PAM_conversation = {
179 static int dhx_setup(void *obj, char *ibuf, int ibuflen,
180 char *rbuf, int *rbuflen)
184 BIGNUM *bn, *gbn, *pbn;
187 /* TODO: seed dhx_setup properly... this is a hack */
189 /* *SEVERE* hack... fix */
190 RAND_load_file("/var/adm/messages", KEYSIZE);
193 /* get the client's public key */
194 if (!(bn = BN_bin2bn(ibuf, KEYSIZE, NULL))) {
196 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM No Public Key -- %s",
203 if (!(gbn = BN_bin2bn(&g, sizeof(g), NULL))) {
206 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM No Primes: GBN -- %s",
212 if (!(pbn = BN_bin2bn(p, sizeof(p), NULL))) {
216 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM No Primes: PBN -- %s",
222 /* okay, we're ready */
223 if (!(dh = DH_new())) {
228 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM DH was equal to DH_New... Go figure... -- %s",
234 /* generate key and make sure that we have enough space */
237 if (!DH_generate_key(dh) || (BN_num_bytes(dh->pub_key) > KEYSIZE)) {
239 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Err Generating Key -- Not enough Space? -- %s",
245 /* figure out the key. store the key in rbuf for now. */
246 i = DH_compute_key(rbuf, bn, dh);
249 CAST_set_key(&castkey, i, rbuf);
251 /* session id. it's just a hashed version of the object pointer. */
252 sessid = dhxhash(obj);
253 memcpy(rbuf, &sessid, sizeof(sessid));
254 rbuf += sizeof(sessid);
255 *rbuflen += sizeof(sessid);
258 BN_bn2bin(dh->pub_key, rbuf);
262 /* buffer to be encrypted */
264 if (uam_afpserver_option(obj, UAM_OPTION_RANDNUM, (void *) randbuf,
268 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Buffer Encryption Err. -- %s",
273 memcpy(rbuf, &randbuf, sizeof(randbuf));
275 /* get the signature. it's always 16 bytes. */
277 if (uam_afpserver_option(obj, UAM_OPTION_SIGNATURE,
278 (void *) &buf, NULL) < 0) {
281 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Signature Retieval Failure -- %s",
286 memcpy(rbuf + KEYSIZE, buf, KEYSIZE);
288 memset(rbuf + KEYSIZE, 0, KEYSIZE);
291 /* encrypt using cast */
292 CAST_cbc_encrypt(rbuf, rbuf, CRYPTBUFLEN, &castkey, msg2_iv,
294 *rbuflen += CRYPTBUFLEN;
297 return AFPERR_AUTHCONT;
303 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Fail - Cast Encryption -- %s",
310 /* dhx login: things are done in a slightly bizarre order to avoid
311 * having to clean things up if there's an error. */
312 static int pam_login(void *obj, struct passwd **uam_pwd,
313 char *ibuf, int ibuflen,
314 char *rbuf, int *rbuflen)
321 /* grab some of the options */
322 if (uam_afpserver_option(obj, UAM_OPTION_USERNAME, (void *) &buf,
325 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: uam_afpserver_option didn't meet uam_option_username -- %s",
331 len = (unsigned char) *ibuf++;
334 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Signature Retieval Failure -- %s",
337 return( AFPERR_PARAM );
340 memcpy(buf, ibuf, len );
343 if ((unsigned long) ibuf & 1) /* pad to even boundary */
346 if (( dhxpwd = uam_getname(buf, i)) == NULL ) {
348 LOG(log_info, logtype_default, "uams_dhx_pam.c: unknown username");
354 LOG(log_info, logtype_default, "dhx login: %s", buf);
355 return dhx_setup(obj, ibuf, ibuflen, rbuf, rbuflen);
359 static int pam_logincont(void *obj, struct passwd **uam_pwd,
360 char *ibuf, int ibuflen,
361 char *rbuf, int *rbuflen)
364 BIGNUM *bn1, *bn2, *bn3;
370 /* check for session id */
371 memcpy(&sessid, ibuf, sizeof(sessid));
372 if (sessid != dhxhash(obj)) {
374 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM Session ID - DHXHash Mismatch -- %s",
379 ibuf += sizeof(sessid);
381 if (uam_afpserver_option(obj, UAM_OPTION_CLIENTNAME,
382 (void *) &hostname, NULL) < 0)
384 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: unable to retrieve client hostname");
388 CAST_cbc_encrypt(ibuf, rbuf, CRYPT2BUFLEN, &castkey,
389 msg3_iv, CAST_DECRYPT);
390 memset(&castkey, 0, sizeof(castkey));
392 /* check to make sure that the random number is the same. we
393 * get sent back an incremented random number. */
394 if (!(bn1 = BN_bin2bn(rbuf, KEYSIZE, NULL)))
397 if (!(bn2 = BN_bin2bn(randbuf, sizeof(randbuf), NULL))) {
402 /* zero out the random number */
403 memset(rbuf, 0, sizeof(randbuf));
404 memset(randbuf, 0, sizeof(randbuf));
407 if (!(bn3 = BN_new())) {
413 BN_sub(bn3, bn1, bn2);
417 /* okay. is it one more? */
418 if (!BN_is_one(bn3)) {
424 /* Set these things up for the conv function */
425 rbuf[PASSWDLEN] = '\0';
428 err = AFPERR_NOTAUTH;
429 PAM_error = pam_start("netatalk", PAM_username, &PAM_conversation,
431 if (PAM_error != PAM_SUCCESS) {
433 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM_Error: %s",
434 pam_strerror(pamh,PAM_error));
439 /* solaris craps out if PAM_TTY and PAM_RHOST aren't set. */
440 pam_set_item(pamh, PAM_TTY, "afpd");
441 pam_set_item(pamh, PAM_RHOST, hostname);
442 PAM_error = pam_authenticate(pamh,0);
443 if (PAM_error != PAM_SUCCESS) {
444 if (PAM_error == PAM_MAXTRIES)
445 err = AFPERR_PWDEXPR;
447 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM_Error: %s",
448 pam_strerror(pamh, PAM_error));
453 PAM_error = pam_acct_mgmt(pamh, 0);
454 if (PAM_error != PAM_SUCCESS) {
455 if (PAM_error == PAM_ACCT_EXPIRED)
456 err = AFPERR_PWDEXPR;
457 #ifdef PAM_AUTHTOKEN_REQD
458 else if (PAM_error == PAM_AUTHTOKEN_REQD)
459 err = AFPERR_PWDCHNG;
462 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM_Error: %s",
463 pam_strerror(pamh, PAM_error));
468 #ifndef PAM_CRED_ESTABLISH
469 #define PAM_CRED_ESTABLISH PAM_ESTABLISH_CRED
471 PAM_error = pam_setcred(pamh, PAM_CRED_ESTABLISH);
472 if (PAM_error != PAM_SUCCESS) {
474 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM_Error: %s",
475 pam_strerror(pamh, PAM_error));
480 PAM_error = pam_open_session(pamh, 0);
481 if (PAM_error != PAM_SUCCESS) {
483 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM_Error: %s",
484 pam_strerror(pamh, PAM_error));
489 memset(rbuf, 0, PASSWDLEN); /* zero out the password */
492 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: PAM Auth OK!");
497 pam_end(pamh, PAM_error);
499 memset(rbuf, 0, CRYPT2BUFLEN);
504 static void pam_logout() {
505 pam_close_session(pamh, 0);
511 /* change pw for dhx needs a couple passes to get everything all
512 * right. basically, it's like the login/logincont sequence */
513 static int pam_changepw(void *obj, char *username,
514 struct passwd *pwd, char *ibuf, int ibuflen,
515 char *rbuf, int *rbuflen)
517 BIGNUM *bn1, *bn2, *bn3;
526 memcpy(&sessid, ibuf, sizeof(sessid));
527 ibuf += sizeof(sessid);
529 if (!sessid) { /* no sessid -> initialization phase */
530 PAM_username = username;
531 ibuflen -= sizeof(sessid);
532 return dhx_setup(obj, ibuf, ibuflen, rbuf, rbuflen);
536 /* otherwise, it's like logincont but different. */
538 /* check out the session id */
539 if (sessid != dhxhash(obj)) {
541 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Session ID not Equal to DHX Hash -- %s",
547 /* we need this for pam */
548 if (uam_afpserver_option(obj, UAM_OPTION_HOSTNAME,
549 (void *) &hostname, NULL) < 0) {
551 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Hostname Null?? -- %s",
557 /* grab the client's nonce, old password, and new password. */
558 CAST_cbc_encrypt(ibuf, ibuf, CHANGEPWBUFLEN, &castkey,
559 msg3_iv, CAST_DECRYPT);
560 memset(&castkey, 0, sizeof(castkey));
562 /* check to make sure that the random number is the same. we
563 * get sent back an incremented random number. */
564 if (!(bn1 = BN_bin2bn(ibuf, KEYSIZE, NULL))) {
566 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Random Number Not the same or not incremented-- %s",
572 if (!(bn2 = BN_bin2bn(randbuf, sizeof(randbuf), NULL))) {
575 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Random Number Not the same or not incremented -- %s",
581 /* zero out the random number */
582 memset(rbuf, 0, sizeof(randbuf));
583 memset(randbuf, 0, sizeof(randbuf));
585 if (!(bn3 = BN_new())) {
589 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Random Number did not Zero -- %s",
595 BN_sub(bn3, bn1, bn2);
599 /* okay. is it one more? */
601 if (!BN_is_one(bn3)) {
604 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: After Random Number not Zero, is it one more? -- %s",
612 /* Set these things up for the conv function. the old password
615 ibuf[PASSWDLEN + PASSWDLEN] = '\0';
616 PAM_password = ibuf + PASSWDLEN;
618 PAM_error = pam_start("netatalk", username, &PAM_conversation,
620 if (PAM_error != PAM_SUCCESS) {
622 LOG(log_info, logtype_default, "uams_dhx_pam.c :PAM: Needless to say, PAM_error is != to PAM_SUCCESS -- %s",
627 pam_set_item(lpamh, PAM_TTY, "afpd");
628 pam_set_item(lpamh, PAM_RHOST, hostname);
630 /* we might need to do this as root */
633 PAM_error = pam_authenticate(lpamh, 0);
634 if (PAM_error != PAM_SUCCESS) {
636 pam_end(lpamh, PAM_error);
637 return AFPERR_NOTAUTH;
640 /* clear out old passwd */
641 memset(ibuf + PASSWDLEN, 0, PASSWDLEN);
645 ibuf[PASSWDLEN] = '\0';
647 /* this really does need to be done as root */
648 PAM_error = pam_chauthtok(lpamh, 0);
649 seteuid(uid); /* un-root ourselves. */
650 memset(ibuf, 0, PASSWDLEN);
651 if (PAM_error != PAM_SUCCESS) {
652 pam_end(lpamh, PAM_error);
653 return AFPERR_ACCESS;
661 static int uam_setup(const char *path)
663 if (uam_register(UAM_SERVER_LOGIN, path, "DHCAST128", pam_login,
664 pam_logincont, pam_logout) < 0)
667 if (uam_register(UAM_SERVER_CHANGEPW, path, "DHCAST128",
669 uam_unregister(UAM_SERVER_LOGIN, "DHCAST128");
673 /*uam_register(UAM_SERVER_PRINTAUTH, path, "DHCAST128",
679 static void uam_cleanup(void)
681 uam_unregister(UAM_SERVER_LOGIN, "DHCAST128");
682 uam_unregister(UAM_SERVER_CHANGEPW, "DHCAST128");
683 /*uam_unregister(UAM_SERVER_PRINTAUTH, "DHCAST128"); */
686 UAM_MODULE_EXPORT struct uam_export uams_dhx = {
689 uam_setup, uam_cleanup
692 UAM_MODULE_EXPORT struct uam_export uams_dhx_pam = {
695 uam_setup, uam_cleanup
698 #endif /* USE_PAM && UAM_DHX */