1/*
2 * Copyright (c) 1990,1993 Regents of The University of Michigan.
3 * Copyright (c) 1999 Adrian Sun (asun@u.washington.edu)
4 * All Rights Reserved.  See COPYRIGHT.
5 */
6
7#ifdef HAVE_CONFIG_H
8#include "config.h"
9#endif /* HAVE_CONFIG_H */
10
11#include <atalk/standards.h>
12
13#include <stdio.h>
14#include <stdlib.h>
15#include <string.h>
16#include <unistd.h>
17#ifdef HAVE_CRYPT_H
18#include <crypt.h>
19#endif /* ! HAVE_CRYPT_H */
20#include <sys/time.h>
21#include <time.h>
22#include <pwd.h>
23#include <arpa/inet.h>
24
25#ifdef SHADOWPW
26#include <shadow.h>
27#endif /* SHADOWPW */
28
29#if defined(GNUTLS_DHX)
30#include <gnutls/openssl.h>
31#elif defined(OPENSSL_DHX)
32#include <openssl/bn.h>
33#include <openssl/dh.h>
34#include <openssl/cast.h>
35#else /* OPENSSL_DHX */
36#include <bn.h>
37#include <dh.h>
38#include <cast.h>
39#endif /* OPENSSL_DHX */
40
41#include <atalk/logger.h>
42#include <atalk/afp.h>
43#include <atalk/uam.h>
44
45#define KEYSIZE 16
46#define PASSWDLEN 64
47#define CRYPTBUFLEN  (KEYSIZE*2)
48#define CRYPT2BUFLEN (KEYSIZE + PASSWDLEN)
49
50/* hash a number to a 16-bit quantity */
51#define dhxhash(a) ((((unsigned long) (a) >> 8) ^ \
52		     (unsigned long) (a)) & 0xffff)
53
54/* the secret key */
55static CAST_KEY castkey;
56static struct passwd *dhxpwd;
57static uint8_t randbuf[16];
58
59#ifdef TRU64
60#include <sia.h>
61#include <siad.h>
62
63static const char *clientname;
64#endif /* TRU64 */
65
66/* dhx passwd */
67static int pwd_login(void *obj, char *username, int ulen, struct passwd **uam_pwd _U_,
68			char *ibuf, size_t ibuflen _U_,
69			char *rbuf, size_t *rbuflen)
70{
71    unsigned char iv[] = "CJalbert";
72    uint8_t p[] = {0xBA, 0x28, 0x73, 0xDF, 0xB0, 0x60, 0x57, 0xD4,
73		    0x3F, 0x20, 0x24, 0x74, 0x4C, 0xEE, 0xE7, 0x5B };
74    uint8_t g = 0x07;
75#ifdef SHADOWPW
76    struct spwd *sp;
77#endif /* SHADOWPW */
78    BIGNUM *bn, *gbn, *pbn;
79    uint16_t sessid;
80    size_t i;
81    DH *dh;
82
83#ifdef TRU64
84    int rnd_seed[256];
85    for (i = 0; i < 256; i++)
86        rnd_seed[i] = random();
87    RAND_seed(rnd_seed, sizeof(rnd_seed));
88#endif /* TRU64 */
89
90    *rbuflen = 0;
91
92#ifdef TRU64
93    if( uam_afpserver_option( obj, UAM_OPTION_CLIENTNAME,
94                              (void *) &clientname, NULL ) < 0 )
95        return AFPERR_PARAM;
96#endif /* TRU64 */
97
98    if (( dhxpwd = uam_getname(obj, username, ulen)) == NULL ) {
99        return AFPERR_NOTAUTH;
100    }
101
102    LOG(log_info, logtype_uams, "dhx login: %s", username);
103    if (uam_checkuser(dhxpwd) < 0)
104      return AFPERR_NOTAUTH;
105
106#ifdef SHADOWPW
107    if (( sp = getspnam( dhxpwd->pw_name )) == NULL ) {
108	LOG(log_info, logtype_uams, "no shadow passwd entry for %s", username);
109	return AFPERR_NOTAUTH;
110    }
111    dhxpwd->pw_passwd = sp->sp_pwdp;
112#endif /* SHADOWPW */
113
114    if (!dhxpwd->pw_passwd)
115      return AFPERR_NOTAUTH;
116
117    /* get the client's public key */
118    if (!(bn = BN_bin2bn((unsigned char *)ibuf, KEYSIZE, NULL))) {
119      return AFPERR_PARAM;
120    }
121
122    /* get our primes */
123    if (!(gbn = BN_bin2bn(&g, sizeof(g), NULL))) {
124      BN_free(bn);
125      return AFPERR_PARAM;
126    }
127
128    if (!(pbn = BN_bin2bn(p, sizeof(p), NULL))) {
129      BN_free(gbn);
130      BN_free(bn);
131      return AFPERR_PARAM;
132    }
133
134    /* okay, we're ready */
135    if (!(dh = DH_new())) {
136      BN_free(pbn);
137      BN_free(gbn);
138      BN_free(bn);
139      return AFPERR_PARAM;
140    }
141
142    /* generate key and make sure we have enough space */
143    dh->p = pbn;
144    dh->g = gbn;
145    if (!DH_generate_key(dh) || (BN_num_bytes(dh->pub_key) > KEYSIZE)) {
146      goto passwd_fail;
147    }
148
149    /* figure out the key. use rbuf as a temporary buffer. */
150    i = DH_compute_key((unsigned char *)rbuf, bn, dh);
151
152    /* set the key */
153    CAST_set_key(&castkey, i, (unsigned char *)rbuf);
154
155    /* session id. it's just a hashed version of the object pointer. */
156    sessid = dhxhash(obj);
157    memcpy(rbuf, &sessid, sizeof(sessid));
158    rbuf += sizeof(sessid);
159    *rbuflen += sizeof(sessid);
160
161    /* send our public key */
162    BN_bn2bin(dh->pub_key, (unsigned char *)rbuf);
163    rbuf += KEYSIZE;
164    *rbuflen += KEYSIZE;
165
166    /* buffer to be encrypted */
167    i = sizeof(randbuf);
168    if (uam_afpserver_option(obj, UAM_OPTION_RANDNUM, (void *) randbuf,
169			     &i) < 0) {
170      *rbuflen = 0;
171      goto passwd_fail;
172    }
173    memcpy(rbuf, &randbuf, sizeof(randbuf));
174
175#if 0
176    /* get the signature. it's always 16 bytes. */
177    if (uam_afpserver_option(obj, UAM_OPTION_SIGNATURE,
178			     (void *) &name, NULL) < 0) {
179      *rbuflen = 0;
180      goto passwd_fail;
181    }
182    memcpy(rbuf + KEYSIZE, name, KEYSIZE);
183#else /* 0 */
184    memset(rbuf + KEYSIZE, 0, KEYSIZE);
185#endif /* 0 */
186
187    /* encrypt using cast */
188    CAST_cbc_encrypt((unsigned char *)rbuf, (unsigned char *)rbuf, CRYPTBUFLEN, &castkey, iv, CAST_ENCRYPT);
189    *rbuflen += CRYPTBUFLEN;
190    BN_free(bn);
191    DH_free(dh);
192    return AFPERR_AUTHCONT;
193
194passwd_fail:
195    BN_free(bn);
196    DH_free(dh);
197    return AFPERR_PARAM;
198}
199
200/* cleartxt login */
201static int passwd_login(void *obj, struct passwd **uam_pwd,
202			char *ibuf, size_t ibuflen,
203			char *rbuf, size_t *rbuflen)
204{
205    char *username;
206    size_t len, ulen;
207
208    *rbuflen = 0;
209
210    if (uam_afpserver_option(obj, UAM_OPTION_USERNAME,
211			     (void *) &username, &ulen) < 0)
212	return AFPERR_MISC;
213
214    if (ibuflen < 2) {
215	return( AFPERR_PARAM );
216    }
217
218    len = (unsigned char) *ibuf++;
219    ibuflen--;
220    if (!len || len > ibuflen || len > ulen ) {
221	return( AFPERR_PARAM );
222    }
223    memcpy(username, ibuf, len );
224    ibuf += len;
225    ibuflen -=len;
226    username[ len ] = '\0';
227
228    if ((unsigned long) ibuf & 1) { /* pad character */
229	++ibuf;
230	ibuflen--;
231    }
232    return (pwd_login(obj, username, ulen, uam_pwd, ibuf, ibuflen, rbuf, rbuflen));
233
234}
235
236/* cleartxt login ext
237 * uname format :
238    byte      3
239    2 bytes   len (network order)
240    len bytes utf8 name
241*/
242static int passwd_login_ext(void *obj, char *uname, struct passwd **uam_pwd,
243			char *ibuf, size_t ibuflen,
244			char *rbuf, size_t *rbuflen)
245{
246    char       *username;
247    size_t     len, ulen;
248    uint16_t  temp16;
249
250    *rbuflen = 0;
251
252    if (uam_afpserver_option(obj, UAM_OPTION_USERNAME,
253			     (void *) &username, &ulen) < 0)
254	return AFPERR_MISC;
255
256    if (*uname != 3)
257	return AFPERR_PARAM;
258    uname++;
259    memcpy(&temp16, uname, sizeof(temp16));
260    len = ntohs(temp16);
261    if (!len || len > ulen ) {
262	return( AFPERR_PARAM );
263    }
264    memcpy(username, uname +2, len );
265    username[ len ] = '\0';
266    return (pwd_login(obj, username, ulen, uam_pwd, ibuf, ibuflen, rbuf, rbuflen));
267}
268
269static int passwd_logincont(void *obj, struct passwd **uam_pwd,
270			    char *ibuf, size_t ibuflen _U_,
271			    char *rbuf, size_t *rbuflen)
272{
273#ifdef SHADOWPW
274    struct spwd *sp;
275#endif /* SHADOWPW */
276    unsigned char iv[] = "LWallace";
277    BIGNUM *bn1, *bn2, *bn3;
278    uint16_t sessid;
279    char *p;
280    int err = AFPERR_NOTAUTH;
281
282    *rbuflen = 0;
283
284    /* check for session id */
285    memcpy(&sessid, ibuf, sizeof(sessid));
286    if (sessid != dhxhash(obj))
287      return AFPERR_PARAM;
288    ibuf += sizeof(sessid);
289
290    /* use rbuf as scratch space */
291    CAST_cbc_encrypt((unsigned char *)ibuf, (unsigned char *)rbuf, CRYPT2BUFLEN, &castkey,
292		     iv, CAST_DECRYPT);
293
294    /* check to make sure that the random number is the same. we
295     * get sent back an incremented random number. */
296    if (!(bn1 = BN_bin2bn((unsigned char *)rbuf, KEYSIZE, NULL)))
297      return AFPERR_PARAM;
298
299    if (!(bn2 = BN_bin2bn(randbuf, sizeof(randbuf), NULL))) {
300      BN_free(bn1);
301      return AFPERR_PARAM;
302    }
303
304    /* zero out the random number */
305    memset(rbuf, 0, sizeof(randbuf));
306    memset(randbuf, 0, sizeof(randbuf));
307    rbuf += KEYSIZE;
308
309    if (!(bn3 = BN_new())) {
310      BN_free(bn2);
311      BN_free(bn1);
312      return AFPERR_PARAM;
313    }
314
315    BN_sub(bn3, bn1, bn2);
316    BN_free(bn2);
317    BN_free(bn1);
318
319    /* okay. is it one more? */
320    if (!BN_is_one(bn3)) {
321      BN_free(bn3);
322      return AFPERR_PARAM;
323    }
324    BN_free(bn3);
325
326    rbuf[PASSWDLEN] = '\0';
327#ifdef TRU64
328    {
329        int ac;
330        char **av;
331        char hostname[256];
332
333        uam_afp_getcmdline( &ac, &av );
334        sprintf( hostname, "%s@%s", dhxpwd->pw_name, clientname );
335
336        if( uam_sia_validate_user( NULL, ac, av, hostname, dhxpwd->pw_name,
337                                   NULL, FALSE, NULL, rbuf ) != SIASUCCESS )
338            return AFPERR_NOTAUTH;
339
340        memset( rbuf, 0, PASSWDLEN );
341        *uam_pwd = dhxpwd;
342        return AFP_OK;
343    }
344#else /* TRU64 */
345    p = crypt( rbuf, dhxpwd->pw_passwd );
346    memset(rbuf, 0, PASSWDLEN);
347    if ( strcmp( p, dhxpwd->pw_passwd ) == 0 ) {
348      *uam_pwd = dhxpwd;
349      err = AFP_OK;
350    }
351#ifdef SHADOWPW
352    if (( sp = getspnam( dhxpwd->pw_name )) == NULL ) {
353	LOG(log_info, logtype_uams, "no shadow passwd entry for %s", dhxpwd->pw_name);
354	return (AFPERR_NOTAUTH);
355    }
356
357    /* check for expired password */
358    if (sp && sp->sp_max != -1 && sp->sp_lstchg) {
359        time_t now = time(NULL) / (60*60*24);
360        int32_t expire_days = sp->sp_lstchg - now + sp->sp_max;
361        if ( expire_days < 0 ) {
362                LOG(log_info, logtype_uams, "password for user %s expired", dhxpwd->pw_name);
363		err = AFPERR_PWDEXPR;
364        }
365    }
366#endif /* SHADOWPW */
367    return err;
368#endif /* TRU64 */
369
370    return AFPERR_NOTAUTH;
371}
372
373
374static int uam_setup(const char *path)
375{
376  if (uam_register(UAM_SERVER_LOGIN_EXT, path, "DHCAST128",
377		   passwd_login, passwd_logincont, NULL, passwd_login_ext) < 0)
378    return -1;
379  /*uam_register(UAM_SERVER_PRINTAUTH, path, "DHCAST128",
380    passwd_printer);*/
381
382  return 0;
383}
384
385static void uam_cleanup(void)
386{
387  uam_unregister(UAM_SERVER_LOGIN, "DHCAST128");
388  /*uam_unregister(UAM_SERVER_PRINTAUTH, "DHCAST128"); */
389}
390
391UAM_MODULE_EXPORT struct uam_export uams_dhx = {
392  UAM_MODULE_SERVER,
393  UAM_MODULE_VERSION,
394  uam_setup, uam_cleanup
395};
396
397UAM_MODULE_EXPORT struct uam_export uams_dhx_passwd = {
398  UAM_MODULE_SERVER,
399  UAM_MODULE_VERSION,
400  uam_setup, uam_cleanup
401};
402