xref: /freebsd/contrib/openpam/lib/libpam/pam_vprompt.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2011 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  * $Id: pam_vprompt.c 648 2013-03-05 17:54:27Z des $
36  */
37 
38 #ifdef HAVE_CONFIG_H
39 # include "config.h"
40 #endif
41 
42 #include <stdarg.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 
46 #include <security/pam_appl.h>
47 
48 #include "openpam_impl.h"
49 
50 /*
51  * OpenPAM extension
52  *
53  * Call the conversation function
54  */
55 
56 int
57 pam_vprompt(const pam_handle_t *pamh,
58 	int style,
59 	char **resp,
60 	const char *fmt,
61 	va_list ap)
62 {
63 	char msgbuf[PAM_MAX_MSG_SIZE];
64 	struct pam_message msg;
65 	const struct pam_message *msgp;
66 	struct pam_response *rsp;
67 	const struct pam_conv *conv;
68 	const void *convp;
69 	int r;
70 
71 	ENTER();
72 	r = pam_get_item(pamh, PAM_CONV, &convp);
73 	if (r != PAM_SUCCESS)
74 		RETURNC(r);
75 	conv = convp;
76 	if (conv == NULL || conv->conv == NULL) {
77 		openpam_log(PAM_LOG_ERROR, "no conversation function");
78 		RETURNC(PAM_SYSTEM_ERR);
79 	}
80 	vsnprintf(msgbuf, PAM_MAX_MSG_SIZE, fmt, ap);
81 	msg.msg_style = style;
82 	msg.msg = msgbuf;
83 	msgp = &msg;
84 	rsp = NULL;
85 	r = (conv->conv)(1, &msgp, &rsp, conv->appdata_ptr);
86 	*resp = rsp == NULL ? NULL : rsp->resp;
87 	FREE(rsp);
88 	RETURNC(r);
89 }
90 
91 /*
92  * Error codes:
93  *
94  *     !PAM_SYMBOL_ERR
95  *	PAM_SYSTEM_ERR
96  *	PAM_BUF_ERR
97  *	PAM_CONV_ERR
98  */
99 
100 /**
101  * The =pam_vprompt function constructs a string from the =fmt and =ap
102  * arguments using =vsnprintf, and passes it to the given PAM context's
103  * conversation function.
104  *
105  * The =style argument specifies the type of interaction requested, and
106  * must be one of the following:
107  *
108  *	=PAM_PROMPT_ECHO_OFF:
109  *		Display the message and obtain the user's response without
110  *		displaying it.
111  *	=PAM_PROMPT_ECHO_ON:
112  *		Display the message and obtain the user's response.
113  *	=PAM_ERROR_MSG:
114  *		Display the message as an error message, and do not wait
115  *		for a response.
116  *	=PAM_TEXT_INFO:
117  *		Display the message as an informational message, and do
118  *		not wait for a response.
119  *
120  * A pointer to the response, or =NULL if the conversation function did
121  * not return one, is stored in the location pointed to by the =resp
122  * argument.
123  *
124  * The message and response should not exceed =PAM_MAX_MSG_SIZE or
125  * =PAM_MAX_RESP_SIZE, respectively.
126  * If they do, they may be truncated.
127  *
128  * >pam_error
129  * >pam_info
130  * >pam_prompt
131  * >pam_verror
132  * >pam_vinfo
133  */
134