source: openpam/trunk/lib/pam_get_authtok.c @ 232

Last change on this file since 232 was 232, checked in by des, 11 years ago

With one single exception (where the pointer is obviously being
immediately overwritten), replace all use of free(3) with a macro
that clears the pointer after freeing the memory it pointed to.

Suggested by: Dmitry V. Levin <ldv@…>

File size: 5.1 KB
Line 
1/*-
2 * Copyright (c) 2002,2003 Networks Associates Technology, Inc.
3 * All rights reserved.
4 *
5 * This software was developed for the FreeBSD Project by ThinkSec AS and
6 * Network Associates Laboratories, the Security Research Division of
7 * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
8 * ("CBOSS"), as part of the DARPA CHATS research program.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote
19 *    products derived from this software without specific prior written
20 *    permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $P4: //depot/projects/openpam/lib/pam_get_authtok.c#23 $
35 */
36
37#include <sys/param.h>
38
39#include <stdlib.h>
40#include <string.h>
41
42#include <security/pam_appl.h>
43#include <security/openpam.h>
44
45#include "openpam_impl.h"
46
47const char authtok_prompt[] = "Password:";
48const char oldauthtok_prompt[] = "Old Password:";
49const char newauthtok_prompt[] = "New Password:";
50
51/*
52 * OpenPAM extension
53 *
54 * Retrieve authentication token
55 */
56
57int
58pam_get_authtok(pam_handle_t *pamh,
59        int item,
60        const char **authtok,
61        const char *prompt)
62{
63        const void *oldauthtok;
64        const char *default_prompt;
65        char *resp, *resp2;
66        int pitem, r, style, twice;
67
68        ENTER();
69        if (pamh == NULL || authtok == NULL)
70                RETURNC(PAM_SYSTEM_ERR);
71        *authtok = NULL;
72        twice = 0;
73        switch (item) {
74        case PAM_AUTHTOK:
75                pitem = PAM_AUTHTOK_PROMPT;
76                default_prompt = authtok_prompt;
77                r = pam_get_item(pamh, PAM_OLDAUTHTOK, &oldauthtok);
78                if (r == PAM_SUCCESS && oldauthtok != NULL) {
79                        default_prompt = newauthtok_prompt;
80                        twice = 1;
81                }
82                break;
83        case PAM_OLDAUTHTOK:
84                pitem = PAM_OLDAUTHTOK_PROMPT;
85                default_prompt = oldauthtok_prompt;
86                twice = 0;
87                break;
88        default:
89                RETURNC(PAM_SYMBOL_ERR);
90        }
91        if (openpam_get_option(pamh, "try_first_pass") ||
92            openpam_get_option(pamh, "use_first_pass")) {
93                r = pam_get_item(pamh, item, (const void **)authtok);
94                if (r == PAM_SUCCESS && *authtok != NULL)
95                        RETURNC(PAM_SUCCESS);
96                else if (openpam_get_option(pamh, "use_first_pass"))
97                        RETURNC(r == PAM_SUCCESS ? PAM_AUTH_ERR : r);
98        }
99        if (prompt == NULL) {
100                r = pam_get_item(pamh, pitem, (const void **)&prompt);
101                if (r != PAM_SUCCESS || prompt == NULL)
102                        prompt = default_prompt;
103        }
104        style = openpam_get_option(pamh, "echo_pass") ?
105            PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF;
106        r = pam_prompt(pamh, style, &resp, "%s", prompt);
107        if (r != PAM_SUCCESS)
108                RETURNC(r);
109        if (twice) {
110                r = pam_prompt(pamh, style, &resp2, "Retype %s", prompt);
111                if (r != PAM_SUCCESS) {
112                        FREE(resp);
113                        RETURNC(r);
114                }
115                if (strcmp(resp, resp2) != 0) {
116                        FREE(resp);
117                        resp = NULL;
118                }
119                FREE(resp2);
120        }
121        if (resp == NULL)
122                RETURNC(PAM_TRY_AGAIN);
123        r = pam_set_item(pamh, item, resp);
124        FREE(resp);
125        if (r != PAM_SUCCESS)
126                RETURNC(r);
127        r = pam_get_item(pamh, item, (const void **)authtok);
128        RETURNC(r);
129}
130
131/*
132 * Error codes:
133 *
134 *      =pam_get_item
135 *      =pam_prompt
136 *      =pam_set_item
137 *      !PAM_SYMBOL_ERR
138 *      PAM_TRY_AGAIN
139 */
140
141/**
142 * The =pam_get_authtok function returns the cached authentication token,
143 * or prompts the user if no token is currently cached.  Either way, a
144 * pointer to the authentication token is stored in the location pointed
145 * to by the =authtok argument.
146 *
147 * The =item argument must have one of the following values:
148 *
149 *      =PAM_AUTHTOK:
150 *              Returns the current authentication token, or the new token
151 *              when changing authentication tokens.
152 *      =PAM_OLDAUTHTOK:
153 *              Returns the previous authentication token when changing
154 *              authentication tokens.
155 *
156 * The =prompt argument specifies a prompt to use if no token is cached.
157 * If it is =NULL, the =PAM_AUTHTOK_PROMPT or =PAM_OLDAUTHTOK_PROMPT item,
158 * as appropriate, will be used.  If that item is also =NULL, a hardcoded
159 * default prompt will be used.
160 *
161 * If =item is set to =PAM_AUTHTOK and there is a non-null =PAM_OLDAUTHTOK
162 * item, =pam_get_authtok will ask the user to confirm the new token by
163 * retyping it.  If there is a mismatch, =pam_get_authtok will return
164 * =PAM_TRY_AGAIN.
165 *
166 * >pam_get_item
167 * >pam_get_user
168 */
Note: See TracBrowser for help on using the repository browser.