archive_read_add_passphrase.c revision 362133 
1/*-
2 * Copyright (c) 2014 Michihiro NAKAJIMA
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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "archive_platform.h"
27__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/archive_read_add_passphrase.c 362133 2020-06-12 23:01:29Z mm $");
28
29#ifdef HAVE_ERRNO_H
30#include <errno.h>
31#endif
32#include "archive_read_private.h"
33
34static void
35add_passphrase_to_tail(struct archive_read *a,
36    struct archive_read_passphrase *p)
37{
38	*a->passphrases.last = p;
39	a->passphrases.last = &p->next;
40	p->next = NULL;
41}
42
43static struct archive_read_passphrase *
44remove_passphrases_from_head(struct archive_read *a)
45{
46	struct archive_read_passphrase *p;
47
48	p = a->passphrases.first;
49	if (p != NULL)
50		a->passphrases.first = p->next;
51	return (p);
52}
53
54static void
55insert_passphrase_to_head(struct archive_read *a,
56    struct archive_read_passphrase *p)
57{
58	p->next = a->passphrases.first;
59	a->passphrases.first = p;
60	if (&a->passphrases.first == a->passphrases.last) {
61		a->passphrases.last = &p->next;
62		p->next = NULL;
63	}
64}
65
66static struct archive_read_passphrase *
67new_read_passphrase(struct archive_read *a, const char *passphrase)
68{
69	struct archive_read_passphrase *p;
70
71	p = malloc(sizeof(*p));
72	if (p == NULL) {
73		archive_set_error(&a->archive, ENOMEM,
74		    "Can't allocate memory");
75		return (NULL);
76	}
77	p->passphrase = strdup(passphrase);
78	if (p->passphrase == NULL) {
79		free(p);
80		archive_set_error(&a->archive, ENOMEM,
81		    "Can't allocate memory");
82		return (NULL);
83	}
84	return (p);
85}
86
87int
88archive_read_add_passphrase(struct archive *_a, const char *passphrase)
89{
90	struct archive_read *a = (struct archive_read *)_a;
91	struct archive_read_passphrase *p;
92
93	archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW,
94		"archive_read_add_passphrase");
95
96	if (passphrase == NULL || passphrase[0] == '\0') {
97		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
98		    "Empty passphrase is unacceptable");
99		return (ARCHIVE_FAILED);
100	}
101
102	p = new_read_passphrase(a, passphrase);
103	if (p == NULL)
104		return (ARCHIVE_FATAL);
105	add_passphrase_to_tail(a, p);
106
107	return (ARCHIVE_OK);
108}
109
110int
111archive_read_set_passphrase_callback(struct archive *_a, void *client_data,
112    archive_passphrase_callback *cb)
113{
114	struct archive_read *a = (struct archive_read *)_a;
115
116	archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW,
117		"archive_read_set_passphrase_callback");
118
119	a->passphrases.callback = cb;
120	a->passphrases.client_data = client_data;
121	return (ARCHIVE_OK);
122}
123
124/*
125 * Call this in advance when you start to get a passphrase for decryption
126 * for a entry.
127 */
128void
129__archive_read_reset_passphrase(struct archive_read *a)
130{
131
132	a->passphrases.candidate = -1;
133}
134
135/*
136 * Get a passphrase for decryption.
137 */
138const char *
139__archive_read_next_passphrase(struct archive_read *a)
140{
141	struct archive_read_passphrase *p;
142	const char *passphrase;
143
144	if (a->passphrases.candidate < 0) {
145		/* Count out how many passphrases we have. */
146		int cnt = 0;
147
148		for (p = a->passphrases.first; p != NULL; p = p->next)
149			cnt++;
150		a->passphrases.candidate = cnt;
151		p = a->passphrases.first;
152	} else if (a->passphrases.candidate > 1) {
153		/* Rotate a passphrase list. */
154		a->passphrases.candidate--;
155		p = remove_passphrases_from_head(a);
156		add_passphrase_to_tail(a, p);
157		/* Pick a new passphrase candidate up. */
158		p = a->passphrases.first;
159	} else if (a->passphrases.candidate == 1) {
160		/* This case is that all candidates failed to decrypt. */
161		a->passphrases.candidate = 0;
162		if (a->passphrases.first->next != NULL) {
163			/* Rotate a passphrase list. */
164			p = remove_passphrases_from_head(a);
165			add_passphrase_to_tail(a, p);
166		}
167		p = NULL;
168	} else  /* There is no passphrase candidate. */
169		p = NULL;
170
171	if (p != NULL)
172		passphrase = p->passphrase;
173	else if (a->passphrases.callback != NULL) {
174		/* Get a passphrase through a call-back function
175		 * since we tried all passphrases out or we don't
176		 * have it. */
177		passphrase = a->passphrases.callback(&a->archive,
178		    a->passphrases.client_data);
179		if (passphrase != NULL) {
180			p = new_read_passphrase(a, passphrase);
181			if (p == NULL)
182				return (NULL);
183			insert_passphrase_to_head(a, p);
184			a->passphrases.candidate = 1;
185		}
186	} else
187		passphrase = NULL;
188
189	return (passphrase);
190}
191