File: support.c

package info (click to toggle)
libpam-tacplus 1.3.8-2
  • links: PTS
  • area: main
  • in suites: bullseye, buster, jessie, jessie-kfreebsd, sid, stretch
  • size: 1,996 kB
  • ctags: 497
  • sloc: sh: 11,338; ansic: 2,323; makefile: 59
file content (286 lines) | stat: -rw-r--r-- 9,462 bytes parent folder | download
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
/* support.c - support functions for pam_tacplus.c
 * 
 * Copyright (C) 2010, Pawel Krawczyk <pawel.krawczyk@hush.com> and
 * Jeroen Nijhof <jeroen@jeroennijhof.nl>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program - see the file COPYING.
 *
 * See `CHANGES' file for revision history.
 */

#define PAM_SM_AUTH
#define PAM_SM_ACCOUNT
#define PAM_SM_SESSION
#define PAM_SM_PASSWORD

#include "support.h"
#include "pam_tacplus.h"

#include <stdlib.h>
#include <string.h>

tacplus_server_t tac_srv[TAC_PLUS_MAXSERVERS];
int tac_srv_no = 0;

char tac_service[64];
char tac_protocol[64];
char tac_prompt[64];

void _pam_log(int err, const char *format,...) {
    char msg[256];
    va_list args;

    va_start(args, format);
    vsnprintf(msg, sizeof(msg), format, args);
    openlog("PAM-tacplus", LOG_PID, LOG_AUTH);
    syslog(err, "%s", msg);
    va_end(args);
    closelog();
}

char *_pam_get_user(pam_handle_t *pamh) {
    int retval;
    char *user;

    retval = pam_get_user(pamh, (void *)&user, "Username: ");
    if (retval != PAM_SUCCESS || user == NULL || *user == '\0') {
        _pam_log(LOG_ERR, "unable to obtain username");
        user = NULL;
    }
    return user;
}

char *_pam_get_terminal(pam_handle_t *pamh) {
    int retval;
    char *tty;

    retval = pam_get_item(pamh, PAM_TTY, (void *)&tty);
    if (retval != PAM_SUCCESS || tty == NULL || *tty == '\0') {
        tty = ttyname(STDIN_FILENO);
        if(tty == NULL || *tty == '\0')
            tty = "unknown";
    }
    return tty;
}

char *_pam_get_rhost(pam_handle_t *pamh) {
    int retval;
    char *rhost;

    retval = pam_get_item(pamh, PAM_RHOST, (void *)&rhost);
    if (retval != PAM_SUCCESS || rhost == NULL || *rhost == '\0') {
        rhost = "unknown";
    }
    return rhost;
}

int converse(pam_handle_t * pamh, int nargs, const struct pam_message *message,
    struct pam_response **response) {

    int retval;
    struct pam_conv *conv;

    if ((retval = pam_get_item (pamh, PAM_CONV, (const void **)&conv)) == PAM_SUCCESS) {
        retval = conv->conv(nargs, &message, response, conv->appdata_ptr);

        if (retval != PAM_SUCCESS) {
            _pam_log(LOG_ERR, "(pam_tacplus) converse returned %d", retval);
            _pam_log(LOG_ERR, "that is: %s", pam_strerror (pamh, retval));
        }
    } else {
        _pam_log (LOG_ERR, "(pam_tacplus) converse failed to get pam_conv");
    }

    return retval;
}

/* stolen from pam_stress */
int tacacs_get_password (pam_handle_t * pamh, int flags
    ,int ctrl, char **password) {

    const void *pam_pass;
    char *pass = NULL;

    if (ctrl & PAM_TAC_DEBUG)
        syslog (LOG_DEBUG, "%s: called", __FUNCTION__);

    if ( (ctrl & (PAM_TAC_TRY_FIRST_PASS | PAM_TAC_USE_FIRST_PASS))
        && (pam_get_item(pamh, PAM_AUTHTOK, &pam_pass) == PAM_SUCCESS)
        && (pam_pass != NULL) ) {
         if ((pass = strdup(pam_pass)) == NULL)
              return PAM_BUF_ERR;
    } else if ((ctrl & PAM_TAC_USE_FIRST_PASS)) {
         _pam_log(LOG_WARNING, "no forwarded password");
         return PAM_PERM_DENIED;
    } else {
         struct pam_message msg;
         struct pam_response *resp = NULL;
         int retval;

         /* set up conversation call */
         msg.msg_style = PAM_PROMPT_ECHO_OFF;

         if (!tac_prompt) {
             msg.msg = "Password: ";
         } else {
             msg.msg = tac_prompt;
         }

         if ((retval = converse (pamh, 1, &msg, &resp)) != PAM_SUCCESS)
             return retval;

         if (resp != NULL) {
             if (resp->resp == NULL && (ctrl & PAM_TAC_DEBUG))
                 _pam_log (LOG_DEBUG, "pam_sm_authenticate: NULL authtok given");

             pass = resp->resp;    /* remember this! */
             resp->resp = NULL;

             free(resp);
             resp = NULL;
         } else {
             if (ctrl & PAM_TAC_DEBUG) {
               _pam_log (LOG_DEBUG, "pam_sm_authenticate: no error reported");
               _pam_log (LOG_DEBUG, "getting password, but NULL returned!?");
             }
             return PAM_CONV_ERR;
         }
    }

    /*
       FIXME *password can still turn out as NULL
       and it can't be free()d when it's NULL
    */
    *password = pass;       /* this *MUST* be free()'d by this module */

    if(ctrl & PAM_TAC_DEBUG)
        syslog(LOG_DEBUG, "%s: obtained password", __FUNCTION__);

    return PAM_SUCCESS;
}

int _pam_parse (int argc, const char **argv) {
    int ctrl = 0;
    const char *current_secret = NULL;

    /* otherwise the list will grow with each call */
    memset(tac_srv, 0, sizeof(tacplus_server_t) * TAC_PLUS_MAXSERVERS);
    tac_srv_no = 0;

    tac_service[0] = 0;
    tac_protocol[0] = 0;
    tac_prompt[0] = 0;
    tac_login[0] = 0;

    for (ctrl = 0; argc-- > 0; ++argv) {
        if (!strcmp (*argv, "debug")) { /* all */
            ctrl |= PAM_TAC_DEBUG;
        } else if (!strcmp (*argv, "use_first_pass")) {
            ctrl |= PAM_TAC_USE_FIRST_PASS;
        } else if (!strcmp (*argv, "try_first_pass")) { 
            ctrl |= PAM_TAC_TRY_FIRST_PASS;
        } else if (!strncmp (*argv, "service=", 8)) { /* author & acct */
            xstrcpy (tac_service, *argv + 8, sizeof(tac_service));
        } else if (!strncmp (*argv, "protocol=", 9)) { /* author & acct */
            xstrcpy (tac_protocol, *argv + 9, sizeof(tac_protocol));
        } else if (!strncmp (*argv, "prompt=", 7)) { /* authentication */
            xstrcpy (tac_prompt, *argv + 7, sizeof(tac_prompt));
            /* Replace _ with space */
            int chr;
            for (chr = 0; chr < strlen(tac_prompt); chr++) {
                if (tac_prompt[chr] == '_') {
                    tac_prompt[chr] = ' ';
                }
            }
        } else if (!strncmp (*argv, "login=", 6)) {
            xstrcpy (tac_login, *argv + 6, sizeof(tac_login));
        } else if (!strcmp (*argv, "acct_all")) {
            ctrl |= PAM_TAC_ACCT;
        } else if (!strncmp (*argv, "server=", 7)) { /* authen & acct */
            if(tac_srv_no < TAC_PLUS_MAXSERVERS) { 
                struct addrinfo hints, *servers, *server;
                int rv;
                char *port, server_buf[256];

                memset(&hints, 0, sizeof hints);
                hints.ai_family = AF_UNSPEC;  /* use IPv4 or IPv6, whichever */
                hints.ai_socktype = SOCK_STREAM;

                if (strlen(*argv + 7) >= sizeof(server_buf)) {
                    _pam_log(LOG_ERR, "server address too long, sorry");
                    continue;
                }
                strcpy(server_buf, *argv + 7);

                port = strchr(server_buf, ':');
                if (port != NULL) {
                    *port = '\0';
					port++;
                }
                if ((rv = getaddrinfo(server_buf, (port == NULL) ? "49" : port, &hints, &servers)) == 0) {
                    for(server = servers; server != NULL && tac_srv_no < TAC_PLUS_MAXSERVERS; server = server->ai_next) {
                        tac_srv[tac_srv_no].addr = server;
                        tac_srv[tac_srv_no].key = current_secret;
                        tac_srv_no++;
                    }
                } else {
                    _pam_log (LOG_ERR,
                        "skip invalid server: %s (getaddrinfo: %s)",
                        server_buf, gai_strerror(rv));
                }
            } else {
                _pam_log(LOG_ERR, "maximum number of servers (%d) exceeded, skipping",
                    TAC_PLUS_MAXSERVERS);
            }
        } else if (!strncmp (*argv, "secret=", 7)) {
            int i;

            current_secret = *argv + 7;     /* points right into argv (which is const) */

            /* if 'secret=' was given after a 'server=' parameter, fill in the current secret */
            for(i = tac_srv_no-1; i >= 0; i--) {
                if (tac_srv[i].key != NULL)
                    break;

                tac_srv[i].key = current_secret;
            }
        } else if (!strncmp (*argv, "timeout=", 8)) {
            /* FIXME atoi() doesn't handle invalid numeric strings well */
            tac_timeout = atoi(*argv + 8);

            if (tac_timeout < 0)
                tac_timeout = 0;
        } else {
            _pam_log (LOG_WARNING, "unrecognized option: %s", *argv);
        }
    }

    if (ctrl & PAM_TAC_DEBUG) {
        int n;

        _pam_log(LOG_DEBUG, "%d servers defined", tac_srv_no);

        for(n = 0; n < tac_srv_no; n++) {
            _pam_log(LOG_DEBUG, "server[%d] { addr=%s, key='%s' }", n, tac_ntop(tac_srv[n].addr->ai_addr), tac_srv[n].key);
        }

        _pam_log(LOG_DEBUG, "tac_service='%s'", tac_service);
        _pam_log(LOG_DEBUG, "tac_protocol='%s'", tac_protocol);
        _pam_log(LOG_DEBUG, "tac_prompt='%s'", tac_prompt);
        _pam_log(LOG_DEBUG, "tac_login='%s'", tac_login);
    }

    return ctrl;
}    /* _pam_parse */