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("$FreeBSD$");
28
29 #ifdef HAVE_ERRNO_H
30 #include <errno.h>
31 #endif
32 #include "archive_read_private.h"
33
34 static void
add_passphrase_to_tail(struct archive_read * a,struct archive_read_passphrase * p)35 add_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
43 static struct archive_read_passphrase *
remove_passphrases_from_head(struct archive_read * a)44 remove_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
54 static void
insert_passphrase_to_head(struct archive_read * a,struct archive_read_passphrase * p)55 insert_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
66 static struct archive_read_passphrase *
new_read_passphrase(struct archive_read * a,const char * passphrase)67 new_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
87 int
archive_read_add_passphrase(struct archive * _a,const char * passphrase)88 archive_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
110 int
archive_read_set_passphrase_callback(struct archive * _a,void * client_data,archive_passphrase_callback * cb)111 archive_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 */
128 void
__archive_read_reset_passphrase(struct archive_read * a)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 */
138 const char *
__archive_read_next_passphrase(struct archive_read * a)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