2 * Copyright (c) 2011 Alex Hornung <alex@alexhornung.com>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in
13 * the documentation and/or other materials provided with the
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
20 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/types.h>
30 #include <sys/param.h>
43 tc_cipher_chain_populate_keys(struct tc_cipher_chain *cipher_chain,
46 int total_key_bytes, used_key_bytes;
47 struct tc_cipher_chain *dummy_chain;
50 * We need to determine the total key bytes as the key locations
54 for (dummy_chain = cipher_chain;
56 dummy_chain = dummy_chain->next) {
57 total_key_bytes += dummy_chain->cipher->klen;
61 * Now we need to get prepare the keys, as the keys are in
62 * forward order with respect to the cipher cascade, but
63 * the actual decryption is in reverse cipher cascade order.
66 for (dummy_chain = cipher_chain;
68 dummy_chain = dummy_chain->next) {
69 dummy_chain->key = alloc_safe_mem(dummy_chain->cipher->klen);
70 if (dummy_chain->key == NULL) {
71 tc_log(1, "tc_decrypt: Could not allocate key "
76 /* XXX: here we assume XTS operation! */
77 memcpy(dummy_chain->key,
78 key + used_key_bytes/2,
79 dummy_chain->cipher->klen/2);
80 memcpy(dummy_chain->key + dummy_chain->cipher->klen/2,
81 key + (total_key_bytes/2) + used_key_bytes/2,
82 dummy_chain->cipher->klen/2);
84 /* Remember how many key bytes we've seen */
85 used_key_bytes += dummy_chain->cipher->klen;
92 tc_cipher_chain_free_keys(struct tc_cipher_chain *cipher_chain)
94 for (; cipher_chain != NULL; cipher_chain = cipher_chain->next) {
95 if (cipher_chain->key != NULL) {
96 free_safe_mem(cipher_chain->key);
97 cipher_chain->key = NULL;
105 tc_encrypt(struct tc_cipher_chain *cipher_chain, unsigned char *key,
107 unsigned char *in, int in_len, unsigned char *out)
109 struct tc_cipher_chain *chain_start;
112 chain_start = cipher_chain;
114 if ((err = tc_cipher_chain_populate_keys(cipher_chain, key)))
118 printf("tc_encrypt: starting chain\n");
122 * Now process the actual decryption, in forward cascade order.
125 cipher_chain != NULL;
126 cipher_chain = cipher_chain->next) {
128 printf("tc_encrypt: Currently using cipher %s\n",
129 cipher_chain->cipher->name);
132 err = syscrypt(cipher_chain->cipher, cipher_chain->key,
133 cipher_chain->cipher->klen, iv, in, out, in_len, 1);
135 /* Deallocate this key, since we won't need it anymore */
136 free_safe_mem(cipher_chain->key);
137 cipher_chain->key = NULL;
140 tc_cipher_chain_free_keys(chain_start);
144 /* Set next input buffer as current output buffer */
148 tc_cipher_chain_free_keys(chain_start);
154 tc_decrypt(struct tc_cipher_chain *cipher_chain, unsigned char *key,
156 unsigned char *in, int in_len, unsigned char *out)
158 struct tc_cipher_chain *chain_start;
161 chain_start = cipher_chain;
163 if ((err = tc_cipher_chain_populate_keys(cipher_chain, key)))
167 printf("tc_decrypt: starting chain!\n");
171 * Now process the actual decryption, in reverse cascade order; so
172 * first find the last element in the chain.
174 for (; cipher_chain->next != NULL; cipher_chain = cipher_chain->next)
177 cipher_chain != NULL;
178 cipher_chain = cipher_chain->prev) {
180 printf("tc_decrypt: Currently using cipher %s\n",
181 cipher_chain->cipher->name);
184 err = syscrypt(cipher_chain->cipher, cipher_chain->key,
185 cipher_chain->cipher->klen, iv, in, out, in_len, 0);
187 /* Deallocate this key, since we won't need it anymore */
188 free_safe_mem(cipher_chain->key);
189 cipher_chain->key = NULL;
192 tc_cipher_chain_free_keys(chain_start);
196 /* Set next input buffer as current output buffer */
200 tc_cipher_chain_free_keys(chain_start);
206 apply_keyfiles(unsigned char *pass, size_t pass_memsz, const char *keyfiles[],
210 unsigned char *kpool;
211 unsigned char *kdata;
216 if (pass_memsz < MAX_PASSSZ) {
217 tc_log(1, "Not enough memory for password manipluation\n");
221 pl = strlen((char *)pass);
222 memset(pass+pl, 0, MAX_PASSSZ-pl);
224 if ((kpool = alloc_safe_mem(KPOOL_SZ)) == NULL) {
225 tc_log(1, "Error allocating memory for keyfile pool\n");
229 memset(kpool, 0, KPOOL_SZ);
231 for (k = 0; k < nkeyfiles; k++) {
233 printf("Loading keyfile %s into kpool\n", keyfiles[k]);
237 kdata_sz = MAX_KFILE_SZ;
239 if ((kdata = read_to_safe_mem(keyfiles[k], 0, &kdata_sz)) == NULL) {
240 tc_log(1, "Error reading keyfile %s content\n",
242 free_safe_mem(kpool);
246 for (i = 0; i < kdata_sz; i++) {
247 crc = crc32_intermediate(crc, kdata[i]);
249 kpool[kpool_idx++] += (unsigned char)(crc >> 24);
250 kpool[kpool_idx++] += (unsigned char)(crc >> 16);
251 kpool[kpool_idx++] += (unsigned char)(crc >> 8);
252 kpool[kpool_idx++] += (unsigned char)(crc);
255 if (kpool_idx == KPOOL_SZ)
259 free_safe_mem(kdata);
263 printf("Applying kpool to passphrase\n");
265 /* Apply keyfile pool to passphrase */
266 for (i = 0; i < KPOOL_SZ; i++)
269 free_safe_mem(kpool);