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
53 total_key_bytes = tc_cipher_chain_klen(cipher_chain);
56 * Now we need to get prepare the keys, as the keys are in
57 * forward order with respect to the cipher cascade, but
58 * the actual decryption is in reverse cipher cascade order.
61 for (dummy_chain = cipher_chain;
63 dummy_chain = dummy_chain->next) {
64 dummy_chain->key = alloc_safe_mem(dummy_chain->cipher->klen);
65 if (dummy_chain->key == NULL) {
66 tc_log(1, "tc_decrypt: Could not allocate key "
71 /* XXX: here we assume XTS operation! */
72 memcpy(dummy_chain->key,
73 key + used_key_bytes/2,
74 dummy_chain->cipher->klen/2);
75 memcpy(dummy_chain->key + dummy_chain->cipher->klen/2,
76 key + (total_key_bytes/2) + used_key_bytes/2,
77 dummy_chain->cipher->klen/2);
79 /* Remember how many key bytes we've seen */
80 used_key_bytes += dummy_chain->cipher->klen;
87 tc_cipher_chain_free_keys(struct tc_cipher_chain *cipher_chain)
89 for (; cipher_chain != NULL; cipher_chain = cipher_chain->next) {
90 if (cipher_chain->key != NULL) {
91 free_safe_mem(cipher_chain->key);
92 cipher_chain->key = NULL;
100 tc_encrypt(struct tc_cipher_chain *cipher_chain, unsigned char *key,
102 unsigned char *in, int in_len, unsigned char *out)
104 struct tc_cipher_chain *chain_start;
107 chain_start = cipher_chain;
109 if ((err = tc_cipher_chain_populate_keys(cipher_chain, key)))
113 printf("tc_encrypt: starting chain\n");
117 * Now process the actual decryption, in forward cascade order.
120 cipher_chain != NULL;
121 cipher_chain = cipher_chain->next) {
123 printf("tc_encrypt: Currently using cipher %s\n",
124 cipher_chain->cipher->name);
127 err = syscrypt(cipher_chain->cipher, cipher_chain->key,
128 cipher_chain->cipher->klen, iv, in, out, in_len, 1);
130 /* Deallocate this key, since we won't need it anymore */
131 free_safe_mem(cipher_chain->key);
132 cipher_chain->key = NULL;
135 tc_cipher_chain_free_keys(chain_start);
139 /* Set next input buffer as current output buffer */
143 tc_cipher_chain_free_keys(chain_start);
149 tc_decrypt(struct tc_cipher_chain *cipher_chain, unsigned char *key,
151 unsigned char *in, int in_len, unsigned char *out)
153 struct tc_cipher_chain *chain_start;
156 chain_start = cipher_chain;
158 if ((err = tc_cipher_chain_populate_keys(cipher_chain, key)))
162 printf("tc_decrypt: starting chain!\n");
166 * Now process the actual decryption, in reverse cascade order; so
167 * first find the last element in the chain.
169 for (; cipher_chain->next != NULL; cipher_chain = cipher_chain->next)
172 cipher_chain != NULL;
173 cipher_chain = cipher_chain->prev) {
175 printf("tc_decrypt: Currently using cipher %s\n",
176 cipher_chain->cipher->name);
179 err = syscrypt(cipher_chain->cipher, cipher_chain->key,
180 cipher_chain->cipher->klen, iv, in, out, in_len, 0);
182 /* Deallocate this key, since we won't need it anymore */
183 free_safe_mem(cipher_chain->key);
184 cipher_chain->key = NULL;
187 tc_cipher_chain_free_keys(chain_start);
191 /* Set next input buffer as current output buffer */
195 tc_cipher_chain_free_keys(chain_start);
201 apply_keyfiles(unsigned char *pass, size_t pass_memsz, const char *keyfiles[],
205 unsigned char *kpool;
206 unsigned char *kdata;
211 if (pass_memsz < MAX_PASSSZ) {
212 tc_log(1, "Not enough memory for password manipulation\n");
216 pl = strlen((char *)pass);
217 memset(pass+pl, 0, MAX_PASSSZ-pl);
219 if ((kpool = alloc_safe_mem(KPOOL_SZ)) == NULL) {
220 tc_log(1, "Error allocating memory for keyfile pool\n");
224 memset(kpool, 0, KPOOL_SZ);
226 for (k = 0; k < nkeyfiles; k++) {
228 printf("Loading keyfile %s into kpool\n", keyfiles[k]);
232 kdata_sz = MAX_KFILE_SZ;
234 if ((kdata = read_to_safe_mem(keyfiles[k], 0, &kdata_sz)) == NULL) {
235 tc_log(1, "Error reading keyfile %s content\n",
237 free_safe_mem(kpool);
241 for (i = 0; i < kdata_sz; i++) {
242 crc = crc32_intermediate(crc, kdata[i]);
244 kpool[kpool_idx++] += (unsigned char)(crc >> 24);
245 kpool[kpool_idx++] += (unsigned char)(crc >> 16);
246 kpool[kpool_idx++] += (unsigned char)(crc >> 8);
247 kpool[kpool_idx++] += (unsigned char)(crc);
250 if (kpool_idx == KPOOL_SZ)
254 free_safe_mem(kdata);
258 printf("Applying kpool to passphrase\n");
260 /* Apply keyfile pool to passphrase */
261 for (i = 0; i < KPOOL_SZ; i++)
264 free_safe_mem(kpool);