source: openpam/trunk/lib/libpam/pam_get_user.c

Last change on this file was 938, checked in by Dag-Erling Smørgrav, 4 years ago

Switch from $Id$ to $OpenPAM$.

  • Property svn:eol-style set to native
  • Property svn:keywords set to OpenPAM=%I
File size: 4.5 KB
Line 
1/*-
2 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3 * Copyright (c) 2004-2017 Dag-Erling Smørgrav
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by ThinkSec AS and
7 * Network Associates Laboratories, the Security Research Division of
8 * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
9 * ("CBOSS"), as part of the DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote
20 *    products derived from this software without specific prior written
21 *    permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * $OpenPAM: pam_get_user.c 938 2017-04-30 21:34:42Z des $
36 */
37
38#ifdef HAVE_CONFIG_H
39# include "config.h"
40#endif
41
42#include <sys/param.h>
43
44#include <stdlib.h>
45
46#include <security/pam_appl.h>
47#include <security/openpam.h>
48
49#include "openpam_impl.h"
50
51static const char user_prompt[] = "Login:";
52
53/*
54 * XSSO 4.2.1
55 * XSSO 6 page 52
56 *
57 * Retrieve user name
58 */
59
60int
61pam_get_user(pam_handle_t *pamh,
62        const char **user,
63        const char *prompt)
64{
65        char prompt_buf[1024];
66        size_t prompt_size;
67        const void *promptp;
68        char *resp;
69        int r;
70
71        ENTER();
72        r = pam_get_item(pamh, PAM_USER, (const void **)user);
73        if (r == PAM_SUCCESS && *user != NULL)
74                RETURNC(PAM_SUCCESS);
75        /* pam policy overrides the module's choice */
76        if ((promptp = openpam_get_option(pamh, "user_prompt")) != NULL)
77                prompt = promptp;
78        /* no prompt provided, see if there is one tucked away somewhere */
79        if (prompt == NULL) {
80                r = pam_get_item(pamh, PAM_USER_PROMPT, &promptp);
81                if (r == PAM_SUCCESS && promptp != NULL)
82                        prompt = promptp;
83        }
84        /* fall back to hardcoded default */
85        if (prompt == NULL)
86                prompt = user_prompt;
87        /* expand */
88        prompt_size = sizeof prompt_buf;
89        r = openpam_subst(pamh, prompt_buf, &prompt_size, prompt);
90        if (r == PAM_SUCCESS && prompt_size <= sizeof prompt_buf)
91                prompt = prompt_buf;
92        r = pam_prompt(pamh, PAM_PROMPT_ECHO_ON, &resp, "%s", prompt);
93        if (r != PAM_SUCCESS)
94                RETURNC(r);
95        r = pam_set_item(pamh, PAM_USER, resp);
96        FREE(resp);
97        if (r != PAM_SUCCESS)
98                RETURNC(r);
99        r = pam_get_item(pamh, PAM_USER, (const void **)user);
100        RETURNC(r);
101}
102
103/*
104 * Error codes:
105 *
106 *      =pam_get_item
107 *      =pam_prompt
108 *      =pam_set_item
109 *      !PAM_SYMBOL_ERR
110 */
111
112/**
113 * The =pam_get_user function returns the name of the target user, as
114 * specified to =pam_start.
115 * If no user was specified, nor set using =pam_set_item, =pam_get_user
116 * will prompt for a user name.
117 * Either way, a pointer to the user name is stored in the location
118 * pointed to by the =user argument, and the corresponding PAM item is
119 * updated.
120 *
121 * The =prompt argument specifies a prompt to use if no user name is
122 * cached.
123 * If it is =NULL, the =PAM_USER_PROMPT item will be used.
124 * If that item is also =NULL, a hardcoded default prompt will be used.
125 * Additionally, when =pam_get_user is called from a service module, the
126 * prompt may be affected by module options as described below.
127 * The prompt is then expanded using =openpam_subst before it is passed to
128 * the conversation function.
129 *
130 * MODULE OPTIONS
131 *
132 * When called by a service module, =pam_get_user will recognize the
133 * following module options:
134 *
135 *      ;user_prompt:
136 *              Prompt to use when asking for the user name.
137 *              This option overrides both the =prompt argument and the
138 *              =PAM_USER_PROMPT item.
139 *
140 * >pam_conv
141 * >pam_get_item
142 * >pam_get_authtok
143 * >openpam_get_option
144 * >openpam_subst
145 */
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