2 * loop-AES compatible volume handling
4 * Copyright (C) 2011-2012, Red Hat, Inc. All rights reserved.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 #include "libcryptsetup.h"
29 static const char *get_hash(unsigned int key_size)
34 case 16: hash = "sha256"; break;
35 case 24: hash = "sha384"; break;
36 case 32: hash = "sha512"; break;
43 static unsigned char get_tweak(unsigned int keys_count)
53 static int hash_key(const char *src, size_t src_len,
54 char *dst, size_t dst_len,
55 const char *hash_name)
57 struct crypt_hash *hd = NULL;
60 if (crypt_hash_init(&hd, hash_name))
63 r = crypt_hash_write(hd, src, src_len);
65 r = crypt_hash_final(hd, dst, dst_len);
67 crypt_hash_destroy(hd);
71 static int hash_keys(struct crypt_device *cd,
72 struct volume_key **vk,
73 const char *hash_override,
74 const char **input_keys,
75 unsigned int keys_count,
76 unsigned int key_len_output)
78 const char *hash_name;
80 unsigned i, key_len_input;
83 hash_name = hash_override ?: get_hash(key_len_output);
84 tweak = get_tweak(keys_count);
85 key_len_input = strlen(input_keys[0]);
87 if (!keys_count || !key_len_output || !hash_name || !key_len_input) {
88 log_err(cd, _("Key processing error (using hash %s).\n"),
89 hash_name ?: "[none]");
93 *vk = crypt_alloc_volume_key(key_len_output * keys_count, NULL);
97 for (i = 0; i < keys_count; i++) {
98 key_ptr = &(*vk)->key[i * key_len_output];
99 r = hash_key(input_keys[i], key_len_input, key_ptr,
100 key_len_output, hash_name);
108 crypt_free_volume_key(*vk);
114 static int keyfile_is_gpg(char *buffer, size_t buffer_len)
117 int index = buffer_len < 100 ? buffer_len - 1 : 100;
118 char eos = buffer[index];
120 buffer[index] = '\0';
121 if (strstr(buffer, "BEGIN PGP MESSAGE"))
127 int LOOPAES_parse_keyfile(struct crypt_device *cd,
128 struct volume_key **vk,
130 unsigned int *keys_count,
134 const char *keys[LOOPAES_KEYS_MAX];
135 unsigned i, key_index, key_len, offset;
137 log_dbg("Parsing loop-AES keyfile of size %d.", buffer_len);
142 if (keyfile_is_gpg(buffer, buffer_len)) {
143 log_err(cd, _("Detected not yet supported GPG encrypted keyfile.\n"));
144 log_std(cd, _("Please use gpg --decrypt <KEYFILE> | cryptsetup --keyfile=- ...\n"));
148 /* Remove EOL in buffer */
149 for (i = 0; i < buffer_len; i++)
150 if (buffer[i] == '\n' || buffer[i] == '\r')
155 while (offset < buffer_len && key_index < LOOPAES_KEYS_MAX) {
156 keys[key_index++] = &buffer[offset];
157 while (offset < buffer_len && buffer[offset])
159 while (offset < buffer_len && !buffer[offset])
163 /* All keys must be the same length */
164 key_len = key_index ? strlen(keys[0]) : 0;
165 for (i = 0; i < key_index; i++)
166 if (key_len != strlen(keys[i])) {
167 log_dbg("Unexpected length %d of key #%d (should be %d).",
168 strlen(keys[i]), i, key_len);
173 log_dbg("Keyfile: %d keys of length %d.", key_index, key_len);
174 if (offset != buffer_len || key_len == 0 ||
175 (key_index != 1 && key_index !=64 && key_index != 65)) {
176 log_err(cd, _("Incompatible loop-AES keyfile detected.\n"));
180 *keys_count = key_index;
181 return hash_keys(cd, vk, hash, keys, key_index, crypt_get_volume_key_size(cd));
184 int LOOPAES_activate(struct crypt_device *cd,
186 const char *base_cipher,
187 unsigned int keys_count,
188 struct volume_key *vk,
194 struct crypt_dm_active_device dmd = {
196 .uuid = crypt_get_uuid(cd),
199 .data_device = crypt_get_device_name(cd),
203 .offset = crypt_get_data_offset(cd),
204 .iv_offset = crypt_get_iv_offset(cd),
209 r = device_check_and_adjust(cd, dmd.data_device, DEV_EXCL,
210 &dmd.size, &dmd.u.crypt.offset, &flags);
214 if (keys_count == 1) {
215 req_flags = DM_PLAIN64_SUPPORTED;
216 r = asprintf(&cipher, "%s-%s", base_cipher, "cbc-plain64");
218 req_flags = DM_LMK_SUPPORTED;
219 r = asprintf(&cipher, "%s:%d-%s", base_cipher, 64, "cbc-lmk");
224 dmd.u.crypt.cipher = cipher;
225 log_dbg("Trying to activate loop-AES device %s using cipher %s.",
226 name, dmd.u.crypt.cipher);
228 r = dm_create_device(name, CRYPT_LOOPAES, &dmd, 0);
230 if (!r && !(dm_flags() & req_flags)) {
231 log_err(cd, _("Kernel doesn't support loop-AES compatible mapping.\n"));