xref: /freebsd/contrib/openpam/lib/libpam/pam_vprompt.c (revision 3ba4c8c81a28de3e00ccf6d7f92c6f8e58bef456)
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 
36 #ifdef HAVE_CONFIG_H
37 # include "config.h"
38 #endif
39 
40 #include <stdarg.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 
44 #include <security/pam_appl.h>
45 
46 #include "openpam_impl.h"
47 
48 /*
49  * OpenPAM extension
50  *
51  * Call the conversation function
52  */
53 
54 int
pam_vprompt(const pam_handle_t * pamh,int style,char ** resp,const char * fmt,va_list ap)55 pam_vprompt(const pam_handle_t *pamh,
56 	int style,
57 	char **resp,
58 	const char *fmt,
59 	va_list ap)
60 {
61 	char msgbuf[PAM_MAX_MSG_SIZE];
62 	struct pam_message msg;
63 	const struct pam_message *msgp;
64 	struct pam_response *rsp;
65 	const struct pam_conv *conv;
66 	const void *convp;
67 	int r;
68 
69 	ENTER();
70 	r = pam_get_item(pamh, PAM_CONV, &convp);
71 	if (r != PAM_SUCCESS)
72 		RETURNC(r);
73 	conv = convp;
74 	if (conv == NULL || conv->conv == NULL) {
75 		openpam_log(PAM_LOG_ERROR, "no conversation function");
76 		RETURNC(PAM_SYSTEM_ERR);
77 	}
78 	vsnprintf(msgbuf, PAM_MAX_MSG_SIZE, fmt, ap);
79 	msg.msg_style = style;
80 	msg.msg = msgbuf;
81 	msgp = &msg;
82 	rsp = NULL;
83 	r = (conv->conv)(1, &msgp, &rsp, conv->appdata_ptr);
84 	*resp = rsp == NULL ? NULL : rsp->resp;
85 	FREE(rsp);
86 	RETURNC(r);
87 }
88 
89 /*
90  * Error codes:
91  *
92  *     !PAM_SYMBOL_ERR
93  *	PAM_SYSTEM_ERR
94  *	PAM_BUF_ERR
95  *	PAM_CONV_ERR
96  */
97 
98 /**
99  * The =pam_vprompt function constructs a string from the =fmt and =ap
100  * arguments using =vsnprintf, and passes it to the given PAM context's
101  * conversation function.
102  *
103  * The =style argument specifies the type of interaction requested, and
104  * must be one of the following:
105  *
106  *	=PAM_PROMPT_ECHO_OFF:
107  *		Display the message and obtain the user's response without
108  *		displaying it.
109  *	=PAM_PROMPT_ECHO_ON:
110  *		Display the message and obtain the user's response.
111  *	=PAM_ERROR_MSG:
112  *		Display the message as an error message, and do not wait
113  *		for a response.
114  *	=PAM_TEXT_INFO:
115  *		Display the message as an informational message, and do
116  *		not wait for a response.
117  *
118  * A pointer to the response, or =NULL if the conversation function did
119  * not return one, is stored in the location pointed to by the =resp
120  * argument.
121  *
122  * The message and response should not exceed =PAM_MAX_MSG_SIZE or
123  * =PAM_MAX_RESP_SIZE, respectively.
124  * If they do, they may be truncated.
125  *
126  * >pam_error
127  * >pam_info
128  * >pam_prompt
129  * >pam_verror
130  * >pam_vinfo
131  */
132