1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
|
/* pam_mail module */
/*
* $Id: pam_mail.c,v 1.2 1997/02/15 16:06:14 morgan Exp morgan $
*
* Written by Andrew Morgan <morgan@parc.power.net> 1996/3/11
* $HOME additions by David Kinchlea <kinch@kinch.ark.com> 1997/1/7
*
* $Log: pam_mail.c,v $
* Revision 1.2 1997/02/15 16:06:14 morgan
* session -> setcred, also added "~"=$HOME
*
* Revision 1.1 1997/01/04 20:33:02 morgan
* Initial revision
*/
#define DEFAULT_MAIL_DIRECTORY "/var/spool/mail"
#define MAIL_FILE_FORMAT "%s/%s"
#define MAIL_ENV_NAME "MAIL"
#define MAIL_ENV_FORMAT MAIL_ENV_NAME "=%s"
#define YOUR_MAIL_FORMAT "You have %s mail in %s"
#ifdef linux
# define _GNU_SOURCE
# include <features.h>
#endif
#include <ctype.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#ifdef WANT_PWDB
#include <pwdb/pwdb_public.h>
#endif
/*
* here, we make a definition for the externally accessible function
* in this file (this definition is required for static a module
* but strongly encouraged generally) it is used to instruct the
* modules include file to define the function prototypes.
*/
#define PAM_SM_AUTH
#include <security/pam_modules.h>
#include <security/_pam_macros.h>
/* some syslogging */
static void _log_err(int err, const char *format, ...)
{
va_list args;
va_start(args, format);
openlog("PAM-mail", LOG_CONS|LOG_PID, LOG_AUTH);
vsyslog(err, format, args);
va_end(args);
closelog();
}
/* argument parsing */
#define PAM_DEBUG_ARG 01
#define PAM_NO_LOGIN 02
#define PAM_LOGOUT_TOO 04
#define PAM_NEW_MAIL_DIR 010
#define PAM_MAIL_SILENT 020
#define PAM_NO_ENV 040
#define PAM_HOME_MAIL 0100
#define PAM_EMPTY_TOO 0200
static int _pam_parse(int flags, int argc, const char **argv, char **maildir)
{
int ctrl=0;
if (flags & PAM_SILENT) {
ctrl |= PAM_MAIL_SILENT;
}
/* step through arguments */
for (; argc-- > 0; ++argv) {
/* generic options */
if (!strcmp(*argv,"debug"))
ctrl |= PAM_DEBUG_ARG;
else if (!strncmp(*argv,"dir=",4)) {
*maildir = x_strdup(4+*argv);
if (*maildir != NULL) {
D(("new mail directory: %s", *maildir));
ctrl |= PAM_NEW_MAIL_DIR;
} else {
_log_err(LOG_CRIT,
"failed to duplicate mail directory - ignored");
}
} else if (!strcmp(*argv,"close")) {
ctrl |= PAM_LOGOUT_TOO;
} else if (!strcmp(*argv,"nopen")) {
ctrl |= PAM_NO_LOGIN;
} else if (!strcmp(*argv,"noenv")) {
ctrl |= PAM_NO_ENV;
} else if (!strcmp(*argv,"empty")) {
ctrl |= PAM_EMPTY_TOO;
} else {
_log_err(LOG_ERR,"pam_parse: unknown option; %s",*argv);
}
}
return ctrl;
}
/* a front end for conversations */
static int converse(pam_handle_t *pamh, int ctrl, int nargs
, struct pam_message **message
, struct pam_response **response)
{
int retval;
struct pam_conv *conv;
D(("begin to converse"));
retval = pam_get_item( pamh, PAM_CONV, (const void **) &conv ) ;
if ( retval == PAM_SUCCESS ) {
retval = conv->conv(nargs, ( const struct pam_message ** ) message
, response, conv->appdata_ptr);
D(("returned from application's conversation function"));
if (retval != PAM_SUCCESS && (PAM_DEBUG_ARG & ctrl) ) {
_log_err(LOG_DEBUG, "conversation failure [%s]"
, pam_strerror(pamh, retval));
}
} else {
_log_err(LOG_ERR, "couldn't obtain coversation function [%s]"
, pam_strerror(pamh, retval));
}
D(("ready to return from module conversation"));
return retval; /* propagate error status */
}
static int get_folder(pam_handle_t *pamh, int ctrl
, char **path_mail, char **folder_p)
{
int retval;
const char *user, *path;
char *folder;
const struct passwd *pwd=NULL;
retval = pam_get_user(pamh, &user, NULL);
if (retval != PAM_SUCCESS || user == NULL) {
_log_err(LOG_ERR, "no user specified");
return PAM_USER_UNKNOWN;
}
if (ctrl & PAM_NEW_MAIL_DIR) {
path = *path_mail;
if (*path == '~') { /* support for $HOME delivery */
pwd = getpwnam(user);
if (pwd == NULL) {
_log_err(LOG_ERR, "user [%s] unknown", user);
_pam_overwrite(*path_mail);
_pam_drop(*path_mail);
return PAM_USER_UNKNOWN;
}
/*
* "~/xxx" and "~xxx" are treated as same
*/
if (!*++path || (*path == '/' && !*++path)) {
_log_err(LOG_ALERT, "badly formed mail path [%s]", *path_mail);
_pam_overwrite(*path_mail);
_pam_drop(*path_mail);
return PAM_ABORT;
}
ctrl |= PAM_HOME_MAIL;
}
} else {
path = DEFAULT_MAIL_DIRECTORY;
}
/* put folder together */
if (ctrl & PAM_HOME_MAIL) {
folder = malloc(sizeof(MAIL_FILE_FORMAT)
+strlen(pwd->pw_dir)+strlen(path));
} else {
folder = malloc(sizeof(MAIL_FILE_FORMAT)+strlen(path)+strlen(user));
}
if (folder != NULL) {
if (ctrl & PAM_HOME_MAIL) {
sprintf(folder, MAIL_FILE_FORMAT, pwd->pw_dir, path);
} else {
sprintf(folder, MAIL_FILE_FORMAT, path, user);
}
D(("folder =[%s]", folder));
}
/* tidy up */
_pam_overwrite(*path_mail);
_pam_drop(*path_mail);
user = NULL;
if (folder == NULL) {
_log_err(LOG_CRIT, "out of memory for mail folder");
return PAM_BUF_ERR;
}
*folder_p = folder;
folder = NULL;
return PAM_SUCCESS;
}
static const char *get_mail_status(int ctrl, const char *folder)
{
const char *type;
struct stat mail_st;
if (stat(folder, &mail_st) == 0 && mail_st.st_size > 0) {
type = (mail_st.st_atime < mail_st.st_mtime) ? "new":"old" ;
} else if (ctrl & PAM_EMPTY_TOO) {
type = "no";
} else {
type = NULL;
}
memset(&mail_st, 0, sizeof(mail_st));
D(("user has %s mail in %s folder", type, folder));
return type;
}
static int report_mail(pam_handle_t *pamh, int ctrl
, const char *type, const char *folder)
{
int retval;
if (!(ctrl & PAM_MAIL_SILENT)) {
char *remark;
remark = malloc(sizeof(YOUR_MAIL_FORMAT)+strlen(type)+strlen(folder));
if (remark == NULL) {
retval = PAM_BUF_ERR;
} else {
struct pam_message msg[1], *mesg[1];
struct pam_response *resp=NULL;
sprintf(remark, YOUR_MAIL_FORMAT, type, folder);
mesg[0] = &msg[0];
msg[0].msg_style = PAM_TEXT_INFO;
msg[0].msg = remark;
retval = converse(pamh, ctrl, 1, mesg, &resp);
_pam_overwrite(remark);
_pam_drop(remark);
if (resp)
_pam_drop_reply(resp, 1);
}
} else {
D(("keeping quiet"));
retval = PAM_SUCCESS;
}
D(("returning %s", pam_strerror(pamh, retval)));
return retval;
}
/* --- authentication management functions (only) --- */
/*
* Cannot use mail to authenticate yourself
*/
PAM_EXTERN
int pam_sm_authenticate(pam_handle_t *pamh,int flags,int argc
,const char **argv)
{
return PAM_IGNORE;
}
/*
* MAIL is a "credential"
*/
PAM_EXTERN
int pam_sm_setcred(pam_handle_t *pamh, int flags, int argc
, const char **argv)
{
int retval, ctrl;
char *path_mail=NULL, *folder;
const char *type;
/*
* this module (un)sets the MAIL environment variable, and checks if
* the user has any new mail.
*/
ctrl = _pam_parse(flags, argc, argv, &path_mail);
/* Do we have anything to do? */
if (!(flags & (PAM_ESTABLISH_CRED|PAM_DELETE_CRED))) {
return PAM_SUCCESS;
}
/* which folder? */
retval = get_folder(pamh, ctrl, &path_mail, &folder);
if (retval != PAM_SUCCESS) {
D(("failed to find folder"));
return retval;
}
/* set the MAIL variable? */
if (!(ctrl & PAM_NO_ENV) && (flags & PAM_ESTABLISH_CRED)) {
char *tmp;
tmp = malloc(strlen(folder)+sizeof(MAIL_ENV_FORMAT));
if (tmp != NULL) {
sprintf(tmp, MAIL_ENV_FORMAT, folder);
D(("setting env: %s", tmp));
retval = pam_putenv(pamh, tmp);
_pam_overwrite(tmp);
_pam_drop(tmp);
if (retval != PAM_SUCCESS) {
_pam_overwrite(folder);
_pam_drop(folder);
_log_err(LOG_CRIT, "unable to set " MAIL_ENV_NAME " variable");
return retval;
}
} else {
_log_err(LOG_CRIT, "no memory for " MAIL_ENV_NAME " variable");
_pam_overwrite(folder);
_pam_drop(folder);
return retval;
}
} else {
D(("not setting " MAIL_ENV_NAME " variable"));
}
/*
* OK. we've got the mail folder... what about its status?
*/
if (((flags & PAM_ESTABLISH_CRED) && !(ctrl & PAM_NO_LOGIN))
|| ((flags & PAM_DELETE_CRED) && (ctrl & PAM_LOGOUT_TOO))) {
type = get_mail_status(ctrl, folder);
if (type != NULL) {
retval = report_mail(pamh, ctrl, type, folder);
type = NULL;
}
}
/*
* Delete environment variable?
*/
if (flags & PAM_DELETE_CRED) {
(void) pam_putenv(pamh, MAIL_ENV_NAME);
}
_pam_overwrite(folder); /* clean up */
_pam_drop(folder);
/* indicate success or failure */
return retval;
}
#ifdef PAM_STATIC
/* static module data */
struct pam_module _pam_mail_modstruct = {
"pam_mail",
pam_sm_authenticate,
pam_sm_setcred,
NULL,
NULL,
NULL,
NULL,
};
#endif
/* end of module definition */
|