1/*-
2 * Copyright (c) 2015-2017 Dag-Erling Sm��rgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote
14 *    products derived from this software without specific prior written
15 *    permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $OpenPAM: t_pam_conv.c 938 2017-04-30 21:34:42Z des $
30 */
31
32#ifdef HAVE_CONFIG_H
33# include "config.h"
34#endif
35
36#include <err.h>
37#include <errno.h>
38#include <stdint.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42
43#include <cryb/test.h>
44
45#include <security/pam_appl.h>
46#include <security/openpam.h>
47
48#include "openpam_impl.h"
49#include "openpam_asprintf.h"
50
51#include "t_pam_conv.h"
52
53/*
54 * Conversation function
55 *
56 * The appdata argument points to a struct t_pam_conv_script which
57 * contains both the expected messages and the desired responses.  If
58 * script.responses is NULL, t_pam_conv() will return PAM_CONV_ERR.  If an
59 * error occurs (incorrect number of messages, messages don't match script
60 * etc.), script.comment will be set to point to a malloc()ed string
61 * describing the error.  Otherwise, t_pam_conv() will return to its
62 * caller a malloc()ed copy of script.responses.
63 */
64int
65t_pam_conv(int nm, const struct pam_message **msgs,
66    struct pam_response **respsp, void *ad)
67{
68	struct t_pam_conv_script *s = ad;
69	struct pam_response *resps;
70	int i;
71
72	/* check message count */
73	if (nm != s->nmsg) {
74		asprintf(&s->comment, "expected %d messages, got %d",
75		    s->nmsg, nm);
76		return (PAM_CONV_ERR);
77	}
78	if (nm <= 0 || nm > PAM_MAX_NUM_MSG) {
79		/* since the previous test passed, this is intentional! */
80		s->comment = NULL;
81		return (PAM_CONV_ERR);
82	}
83
84	/* check each message and provide the sed answer */
85	if ((resps = calloc(nm, sizeof *resps)) == NULL)
86		goto enomem;
87	for (i = 0; i < nm; ++i) {
88		if (msgs[i]->msg_style != s->msgs[i].msg_style) {
89			asprintf(&s->comment,
90			    "message %d expected style %d got %d", i,
91			    s->msgs[i].msg_style, msgs[i]->msg_style);
92			goto fail;
93		}
94		if (strcmp(msgs[i]->msg, s->msgs[i].msg) != 0) {
95			asprintf(&s->comment,
96			    "message %d expected \"%s\" got \"%s\"", i,
97			    s->msgs[i].msg, msgs[i]->msg);
98			goto fail;
99		}
100		switch (msgs[i]->msg_style) {
101		case PAM_PROMPT_ECHO_OFF:
102			t_printv("[PAM_PROMPT_ECHO_OFF] %s\n", msgs[i]->msg);
103			break;
104		case PAM_PROMPT_ECHO_ON:
105			t_printv("[PAM_PROMPT_ECHO_ON] %s\n", msgs[i]->msg);
106			break;
107		case PAM_ERROR_MSG:
108			t_printv("[PAM_ERROR_MSG] %s\n", msgs[i]->msg);
109			break;
110		case PAM_TEXT_INFO:
111			t_printv("[PAM_TEXT_INFO] %s\n", msgs[i]->msg);
112			break;
113		default:
114			asprintf(&s->comment, "invalid message style %d",
115			    msgs[i]->msg_style);
116			goto fail;
117		}
118		/* copy the response, if there is one */
119		if (s->resps[i].resp != NULL &&
120		    (resps[i].resp = strdup(s->resps[i].resp)) == NULL)
121			goto enomem;
122		resps[i].resp_retcode = s->resps[i].resp_retcode;
123	}
124	s->comment = NULL;
125	*respsp = resps;
126	return (PAM_SUCCESS);
127enomem:
128	asprintf(&s->comment, "%s", strerror(ENOMEM));
129fail:
130	for (i = 0; i < nm; ++i)
131		free(resps[i].resp);
132	free(resps);
133	return (PAM_CONV_ERR);
134}
135