diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/tcrypt/tcrypt.c | 1131 | ||||
| -rw-r--r-- | lib/tcrypt/tcrypt.h | 121 |
2 files changed, 1252 insertions, 0 deletions
diff --git a/lib/tcrypt/tcrypt.c b/lib/tcrypt/tcrypt.c new file mode 100644 index 0000000..bf20b69 --- /dev/null +++ b/lib/tcrypt/tcrypt.c @@ -0,0 +1,1131 @@ +/* + * TCRYPT (TrueCrypt-compatible) and VeraCrypt volume handling + * + * Copyright (C) 2012-2021 Red Hat, Inc. All rights reserved. + * Copyright (C) 2012-2021 Milan Broz + * + * This file is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This file is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#include "libcryptsetup.h" +#include "tcrypt.h" +#include "internal.h" + +/* TCRYPT PBKDF variants */ +static const struct { + unsigned int legacy:1; + unsigned int veracrypt:1; + const char *name; + const char *hash; + unsigned int iterations; + uint32_t veracrypt_pim_const; + uint32_t veracrypt_pim_mult; +} tcrypt_kdf[] = { + { 0, 0, "pbkdf2", "ripemd160", 2000, 0, 0 }, + { 0, 0, "pbkdf2", "ripemd160", 1000, 0, 0 }, + { 0, 0, "pbkdf2", "sha512", 1000, 0, 0 }, + { 0, 0, "pbkdf2", "whirlpool", 1000, 0, 0 }, + { 1, 0, "pbkdf2", "sha1", 2000, 0, 0 }, + { 0, 1, "pbkdf2", "sha512", 500000, 15000, 1000 }, + { 0, 1, "pbkdf2", "whirlpool", 500000, 15000, 1000 }, + { 0, 1, "pbkdf2", "sha256", 500000, 15000, 1000 }, // VeraCrypt 1.0f + { 0, 1, "pbkdf2", "sha256", 200000, 0, 2048 }, // boot only + { 0, 1, "pbkdf2", "ripemd160", 655331, 15000, 1000 }, + { 0, 1, "pbkdf2", "ripemd160", 327661, 0, 2048 }, // boot only + { 0, 1, "pbkdf2", "stribog512",500000, 15000, 1000 }, +// { 0, 1, "pbkdf2", "stribog512",200000, 0, 2048 }, // boot only + { 0, 0, NULL, NULL, 0, 0, 0 } +}; + +struct tcrypt_alg { + const char *name; + unsigned int key_size; + unsigned int iv_size; + unsigned int key_offset; + unsigned int iv_offset; /* or tweak key offset */ + unsigned int key_extra_size; +}; + +struct tcrypt_algs { + unsigned int legacy:1; + unsigned int chain_count; + unsigned int chain_key_size; + const char *long_name; + const char *mode; + struct tcrypt_alg cipher[3]; +}; + +/* TCRYPT cipher variants */ +static struct tcrypt_algs tcrypt_cipher[] = { +/* XTS mode */ +{0,1,64,"aes","xts-plain64", + {{"aes", 64,16,0,32,0}}}, +{0,1,64,"serpent","xts-plain64", + {{"serpent",64,16,0,32,0}}}, +{0,1,64,"twofish","xts-plain64", + {{"twofish",64,16,0,32,0}}}, +{0,2,128,"twofish-aes","xts-plain64", + {{"twofish",64,16, 0,64,0}, + {"aes", 64,16,32,96,0}}}, +{0,3,192,"serpent-twofish-aes","xts-plain64", + {{"serpent",64,16, 0, 96,0}, + {"twofish",64,16,32,128,0}, + {"aes", 64,16,64,160,0}}}, +{0,2,128,"aes-serpent","xts-plain64", + {{"aes", 64,16, 0,64,0}, + {"serpent",64,16,32,96,0}}}, +{0,3,192,"aes-twofish-serpent","xts-plain64", + {{"aes", 64,16, 0, 96,0}, + {"twofish",64,16,32,128,0}, + {"serpent",64,16,64,160,0}}}, +{0,2,128,"serpent-twofish","xts-plain64", + {{"serpent",64,16, 0,64,0}, + {"twofish",64,16,32,96,0}}}, +{0,1,64,"camellia","xts-plain64", + {{"camellia", 64,16,0,32,0}}}, +{0,1,64,"kuznyechik","xts-plain64", + {{"kuznyechik", 64,16,0,32,0}}}, +{0,2,128,"kuznyechik-camellia","xts-plain64", + {{"kuznyechik",64,16, 0,64,0}, + {"camellia", 64,16,32,96,0}}}, +{0,2,128,"twofish-kuznyechik","xts-plain64", + {{"twofish", 64,16, 0,64,0}, + {"kuznyechik",64,16,32,96,0}}}, +{0,2,128,"serpent-camellia","xts-plain64", + {{"serpent", 64,16, 0,64,0}, + {"camellia", 64,16,32,96,0}}}, +{0,2,128,"aes-kuznyechik","xts-plain64", + {{"aes", 64,16, 0,64,0}, + {"kuznyechik",64,16,32,96,0}}}, +{0,3,192,"camellia-serpent-kuznyechik","xts-plain64", + {{"camellia", 64,16, 0, 96,0}, + {"serpent", 64,16,32,128,0}, + {"kuznyechik",64,16,64,160,0}}}, + +/* LRW mode */ +{0,1,48,"aes","lrw-benbi", + {{"aes", 48,16,32,0,0}}}, +{0,1,48,"serpent","lrw-benbi", + {{"serpent",48,16,32,0,0}}}, +{0,1,48,"twofish","lrw-benbi", + {{"twofish",48,16,32,0,0}}}, +{0,2,96,"twofish-aes","lrw-benbi", + {{"twofish",48,16,32,0,0}, + {"aes", 48,16,64,0,0}}}, +{0,3,144,"serpent-twofish-aes","lrw-benbi", + {{"serpent",48,16,32,0,0}, + {"twofish",48,16,64,0,0}, + {"aes", 48,16,96,0,0}}}, +{0,2,96,"aes-serpent","lrw-benbi", + {{"aes", 48,16,32,0,0}, + {"serpent",48,16,64,0,0}}}, +{0,3,144,"aes-twofish-serpent","lrw-benbi", + {{"aes", 48,16,32,0,0}, + {"twofish",48,16,64,0,0}, + {"serpent",48,16,96,0,0}}}, +{0,2,96,"serpent-twofish", "lrw-benbi", + {{"serpent",48,16,32,0,0}, + {"twofish",48,16,64,0,0}}}, + +/* Kernel LRW block size is fixed to 16 bytes for GF(2^128) + * thus cannot be used with blowfish where block is 8 bytes. + * There also no GF(2^64) support. +{1,1,64,"blowfish_le","lrw-benbi", + {{"blowfish_le",64,8,32,0,0}}}, +{1,2,112,"blowfish_le-aes","lrw-benbi", + {{"blowfish_le",64, 8,32,0,0}, + {"aes", 48,16,88,0,0}}}, +{1,3,160,"serpent-blowfish_le-aes","lrw-benbi", + {{"serpent", 48,16, 32,0,0}, + {"blowfish_le",64, 8, 64,0,0}, + {"aes", 48,16,120,0,0}}},*/ + +/* + * CBC + "outer" CBC (both with whitening) + * chain_key_size: alg_keys_bytes + IV_seed_bytes + whitening_bytes + */ +{1,1,32+16+16,"aes","cbc-tcw", + {{"aes", 32,16,32,0,32}}}, +{1,1,32+16+16,"serpent","cbc-tcw", + {{"serpent",32,16,32,0,32}}}, +{1,1,32+16+16,"twofish","cbc-tcw", + {{"twofish",32,16,32,0,32}}}, +{1,2,64+16+16,"twofish-aes","cbci-tcrypt", + {{"twofish",32,16,32,0,0}, + {"aes", 32,16,64,0,32}}}, +{1,3,96+16+16,"serpent-twofish-aes","cbci-tcrypt", + {{"serpent",32,16,32,0,0}, + {"twofish",32,16,64,0,0}, + {"aes", 32,16,96,0,32}}}, +{1,2,64+16+16,"aes-serpent","cbci-tcrypt", + {{"aes", 32,16,32,0,0}, + {"serpent",32,16,64,0,32}}}, +{1,3,96+16+16,"aes-twofish-serpent", "cbci-tcrypt", + {{"aes", 32,16,32,0,0}, + {"twofish",32,16,64,0,0}, + {"serpent",32,16,96,0,32}}}, +{1,2,64+16+16,"serpent-twofish", "cbci-tcrypt", + {{"serpent",32,16,32,0,0}, + {"twofish",32,16,64,0,32}}}, +{1,1,16+8+16,"cast5","cbc-tcw", + {{"cast5", 16,8,32,0,24}}}, +{1,1,24+8+16,"des3_ede","cbc-tcw", + {{"des3_ede",24,8,32,0,24}}}, +{1,1,56+8+16,"blowfish_le","cbc-tcrypt", + {{"blowfish_le",56,8,32,0,24}}}, +{1,2,88+16+16,"blowfish_le-aes","cbc-tcrypt", + {{"blowfish_le",56, 8,32,0,0}, + {"aes", 32,16,88,0,32}}}, +{1,3,120+16+16,"serpent-blowfish_le-aes","cbc-tcrypt", + {{"serpent", 32,16, 32,0,0}, + {"blowfish_le",56, 8, 64,0,0}, + {"aes", 32,16,120,0,32}}}, +{} +}; + +static int TCRYPT_hdr_from_disk(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params, + int kdf_index, int cipher_index) +{ + uint32_t crc32; + size_t size; + + /* Check CRC32 of header */ + size = TCRYPT_HDR_LEN - sizeof(hdr->d.keys) - sizeof(hdr->d.header_crc32); + crc32 = crypt_crc32(~0, (unsigned char*)&hdr->d, size) ^ ~0; + if (be16_to_cpu(hdr->d.version) > 3 && + crc32 != be32_to_cpu(hdr->d.header_crc32)) { + log_dbg(cd, "TCRYPT header CRC32 mismatch."); + return -EINVAL; + } + + /* Check CRC32 of keys */ + crc32 = crypt_crc32(~0, (unsigned char*)hdr->d.keys, sizeof(hdr->d.keys)) ^ ~0; + if (crc32 != be32_to_cpu(hdr->d.keys_crc32)) { + log_dbg(cd, "TCRYPT keys CRC32 mismatch."); + return -EINVAL; + } + + /* Convert header to cpu format */ + hdr->d.version = be16_to_cpu(hdr->d.version); + hdr->d.version_tc = be16_to_cpu(hdr->d.version_tc); + + hdr->d.keys_crc32 = be32_to_cpu(hdr->d.keys_crc32); + + hdr->d.hidden_volume_size = be64_to_cpu(hdr->d.hidden_volume_size); + hdr->d.volume_size = be64_to_cpu(hdr->d.volume_size); + + hdr->d.mk_offset = be64_to_cpu(hdr->d.mk_offset); + if (!hdr->d.mk_offset) + hdr->d.mk_offset = 512; + + hdr->d.mk_size = be64_to_cpu(hdr->d.mk_size); + + hdr->d.flags = be32_to_cpu(hdr->d.flags); + + hdr->d.sector_size = be32_to_cpu(hdr->d.sector_size); + if (!hdr->d.sector_size) + hdr->d.sector_size = 512; + + hdr->d.header_crc32 = be32_to_cpu(hdr->d.header_crc32); + + /* Set params */ + params->passphrase = NULL; + params->passphrase_size = 0; + params->hash_name = tcrypt_kdf[kdf_index].hash; + params->key_size = tcrypt_cipher[cipher_index].chain_key_size; + params->cipher = tcrypt_cipher[cipher_index].long_name; + params->mode = tcrypt_cipher[cipher_index].mode; + + return 0; +} + +/* + * Kernel implements just big-endian version of blowfish, hack it here + */ +static void TCRYPT_swab_le(char *buf) +{ + uint32_t *l = (uint32_t*)&buf[0]; + uint32_t *r = (uint32_t*)&buf[4]; + *l = swab32(*l); + *r = swab32(*r); +} + +static int decrypt_blowfish_le_cbc(struct tcrypt_alg *alg, + const char *key, char *buf) +{ + int bs = alg->iv_size; + char iv[bs], iv_old[bs]; + struct crypt_cipher *cipher = NULL; + int i, j, r; + + assert(bs == 2*sizeof(uint32_t)); + + r = crypt_cipher_init(&cipher, "blowfish", "ecb", + &key[alg->key_offset], alg->key_size); + if (r < 0) + return r; + + memcpy(iv, &key[alg->iv_offset], alg->iv_size); + for (i = 0; i < TCRYPT_HDR_LEN; i += bs) { + memcpy(iv_old, &buf[i], bs); + TCRYPT_swab_le(&buf[i]); + r = crypt_cipher_decrypt(cipher, &buf[i], &buf[i], + bs, NULL, 0); + TCRYPT_swab_le(&buf[i]); + if (r < 0) + break; + for (j = 0; j < bs; j++) + buf[i + j] ^= iv[j]; + memcpy(iv, iv_old, bs); + } + + crypt_cipher_destroy(cipher); + crypt_safe_memzero(iv, bs); + crypt_safe_memzero(iv_old, bs); + return r; +} + +static void TCRYPT_remove_whitening(char *buf, const char *key) +{ + int j; + + for (j = 0; j < TCRYPT_HDR_LEN; j++) + buf[j] ^= key[j % 8]; +} + +static void TCRYPT_copy_key(struct tcrypt_alg *alg, const char *mode, + char *out_key, const char *key) +{ + int ks2; + if (!strncmp(mode, "xts", 3)) { + ks2 = alg->key_size / 2; + memcpy(out_key, &key[alg->key_offset], ks2); + memcpy(&out_key[ks2], &key[alg->iv_offset], ks2); + } else if (!strncmp(mode, "lrw", 3)) { + ks2 = alg->key_size - TCRYPT_LRW_IKEY_LEN; + memcpy(out_key, &key[alg->key_offset], ks2); + memcpy(&out_key[ks2], key, TCRYPT_LRW_IKEY_LEN); + } else if (!strncmp(mode, "cbc", 3)) { + memcpy(out_key, &key[alg->key_offset], alg->key_size); + /* IV + whitening */ + memcpy(&out_key[alg->key_size], &key[alg->iv_offset], + alg->key_extra_size); + } +} + +static int TCRYPT_decrypt_hdr_one(struct tcrypt_alg *alg, const char *mode, + const char *key,struct tcrypt_phdr *hdr) +{ + char backend_key[TCRYPT_HDR_KEY_LEN]; + char iv[TCRYPT_HDR_IV_LEN] = {}; + char mode_name[MAX_CIPHER_LEN + 1]; + struct crypt_cipher *cipher; + char *c, *buf = (char*)&hdr->e; + int r; + + /* Remove IV if present */ + mode_name[MAX_CIPHER_LEN] = '\0'; + strncpy(mode_name, mode, MAX_CIPHER_LEN); + c = strchr(mode_name, '-'); + if (c) + *c = '\0'; + + if (!strncmp(mode, "lrw", 3)) + iv[alg->iv_size - 1] = 1; + else if (!strncmp(mode, "cbc", 3)) { + TCRYPT_remove_whitening(buf, &key[8]); + if (!strcmp(alg->name, "blowfish_le")) + return decrypt_blowfish_le_cbc(alg, key, buf); + memcpy(iv, &key[alg->iv_offset], alg->iv_size); + } + + TCRYPT_copy_key(alg, mode, backend_key, key); + r = crypt_cipher_init(&cipher, alg->name, mode_name, + backend_key, alg->key_size); + if (!r) { + r = crypt_cipher_decrypt(cipher, buf, buf, TCRYPT_HDR_LEN, + iv, alg->iv_size); + crypt_cipher_destroy(cipher); + } + + crypt_safe_memzero(backend_key, sizeof(backend_key)); + crypt_safe_memzero(iv, TCRYPT_HDR_IV_LEN); + return r; +} + +/* + * For chained ciphers and CBC mode we need "outer" decryption. + * Backend doesn't provide this, so implement it here directly using ECB. + */ +static int TCRYPT_decrypt_cbci(struct tcrypt_algs *ciphers, + const char *key, struct tcrypt_phdr *hdr) +{ + struct crypt_cipher *cipher[ciphers->chain_count]; + unsigned int bs = ciphers->cipher[0].iv_size; + char *buf = (char*)&hdr->e, iv[bs], iv_old[bs]; + unsigned int i, j; + int r = -EINVAL; + + TCRYPT_remove_whitening(buf, &key[8]); + + memcpy(iv, &key[ciphers->cipher[0].iv_offset], bs); + + /* Initialize all ciphers in chain in ECB mode */ + for (j = 0; j < ciphers->chain_count; j++) + cipher[j] = NULL; + for (j = 0; j < ciphers->chain_count; j++) { + r = crypt_cipher_init(&cipher[j], ciphers->cipher[j].name, "ecb", + &key[ciphers->cipher[j].key_offset], + ciphers->cipher[j].key_size); + if (r < 0) + goto out; + } + + /* Implements CBC with chained ciphers in loop inside */ + for (i = 0; i < TCRYPT_HDR_LEN; i += bs) { + memcpy(iv_old, &buf[i], bs); + for (j = ciphers->chain_count; j > 0; j--) { + r = crypt_cipher_decrypt(cipher[j - 1], &buf[i], &buf[i], + bs, NULL, 0); + if (r < 0) + goto out; + } + for (j = 0; j < bs; j++) + buf[i + j] ^= iv[j]; + memcpy(iv, iv_old, bs); + } +out: + for (j = 0; j < ciphers->chain_count; j++) + if (cipher[j]) + crypt_cipher_destroy(cipher[j]); + + crypt_safe_memzero(iv, bs); + crypt_safe_memzero(iv_old, bs); + return r; +} + +static int TCRYPT_decrypt_hdr(struct crypt_device *cd, struct tcrypt_phdr *hdr, + const char *key, uint32_t flags) +{ + struct tcrypt_phdr hdr2; + int i, j, r = -EINVAL; + + for (i = 0; tcrypt_cipher[i].chain_count; i++) { + if (!(flags & CRYPT_TCRYPT_LEGACY_MODES) && tcrypt_cipher[i].legacy) + continue; + log_dbg(cd, "TCRYPT: trying cipher %s-%s", + tcrypt_cipher[i].long_name, tcrypt_cipher[i].mode); + + memcpy(&hdr2.e, &hdr->e, TCRYPT_HDR_LEN); + + if (!strncmp(tcrypt_cipher[i].mode, "cbci", 4)) + r = TCRYPT_decrypt_cbci(&tcrypt_cipher[i], key, &hdr2); + else for (j = tcrypt_cipher[i].chain_count - 1; j >= 0 ; j--) { + if (!tcrypt_cipher[i].cipher[j].name) + continue; + r = TCRYPT_decrypt_hdr_one(&tcrypt_cipher[i].cipher[j], + tcrypt_cipher[i].mode, key, &hdr2); + if (r < 0) + break; + } + + if (r < 0) { + log_dbg(cd, "TCRYPT: returned error %d, skipped.", r); + if (r == -ENOTSUP) + break; + r = -ENOENT; + continue; + } + + if (!strncmp(hdr2.d.magic, TCRYPT_HDR_MAGIC, TCRYPT_HDR_MAGIC_LEN)) { + log_dbg(cd, "TCRYPT: Signature magic detected."); + memcpy(&hdr->e, &hdr2.e, TCRYPT_HDR_LEN); + r = i; + break; + } + if ((flags & CRYPT_TCRYPT_VERA_MODES) && + !strncmp(hdr2.d.magic, VCRYPT_HDR_MAGIC, TCRYPT_HDR_MAGIC_LEN)) { + log_dbg(cd, "TCRYPT: Signature magic detected (Veracrypt)."); + memcpy(&hdr->e, &hdr2.e, TCRYPT_HDR_LEN); + r = i; + break; + } + r = -EPERM; + } + + crypt_safe_memzero(&hdr2, sizeof(hdr2)); + return r; +} + +static int TCRYPT_pool_keyfile(struct crypt_device *cd, + unsigned char pool[VCRYPT_KEY_POOL_LEN], + const char *keyfile, int keyfiles_pool_length) +{ + unsigned char *data; + int i, j, fd, data_size, r = -EIO; + uint32_t crc; + + log_dbg(cd, "TCRYPT: using keyfile %s.", keyfile); + + data = malloc(TCRYPT_KEYFILE_LEN); + if (!data) + return -ENOMEM; + memset(data, 0, TCRYPT_KEYFILE_LEN); + + fd = open(keyfile, O_RDONLY); + if (fd < 0) { + log_err(cd, _("Failed to open key file.")); + goto out; + } + + data_size = read_buffer(fd, data, TCRYPT_KEYFILE_LEN); + close(fd); + if (data_size < 0) { + log_err(cd, _("Error reading keyfile %s."), keyfile); + goto out; + } + + for (i = 0, j = 0, crc = ~0U; i < data_size; i++) { + crc = crypt_crc32(crc, &data[i], 1); + pool[j++] += (unsigned char)(crc >> 24); + pool[j++] += (unsigned char)(crc >> 16); + pool[j++] += (unsigned char)(crc >> 8); + pool[j++] += (unsigned char)(crc); + j %= keyfiles_pool_length; + } + r = 0; +out: + crypt_safe_memzero(&crc, sizeof(crc)); + crypt_safe_memzero(data, TCRYPT_KEYFILE_LEN); + free(data); + + return r; +} + +static int TCRYPT_init_hdr(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params) +{ + unsigned char pwd[VCRYPT_KEY_POOL_LEN] = {}; + size_t passphrase_size, max_passphrase_size; + char *key; + unsigned int i, skipped = 0, iterations; + int r = -EPERM, keyfiles_pool_length; + + if (posix_memalign((void*)&key, crypt_getpagesize(), TCRYPT_HDR_KEY_LEN)) + return -ENOMEM; + + if (params->flags & CRYPT_TCRYPT_VERA_MODES && + params->passphrase_size > TCRYPT_KEY_POOL_LEN) { + /* Really. Keyfile pool length depends on passphrase size in Veracrypt. */ + max_passphrase_size = VCRYPT_KEY_POOL_LEN; + keyfiles_pool_length = VCRYPT_KEY_POOL_LEN; + } else { + max_passphrase_size = TCRYPT_KEY_POOL_LEN; + keyfiles_pool_length = TCRYPT_KEY_POOL_LEN; + } + + if (params->keyfiles_count) + passphrase_size = max_passphrase_size; + else + passphrase_size = params->passphrase_size; + + if (params->passphrase_size > max_passphrase_size) { + log_err(cd, _("Maximum TCRYPT passphrase length (%zu) exceeded."), + max_passphrase_size); + goto out; + } + + /* Calculate pool content from keyfiles */ + for (i = 0; i < params->keyfiles_count; i++) { + r = TCRYPT_pool_keyfile(cd, pwd, params->keyfiles[i], keyfiles_pool_length); + if (r < 0) + goto out; + } + + /* If provided password, combine it with pool */ + for (i = 0; i < params->passphrase_size; i++) + pwd[i] += params->passphrase[i]; + + for (i = 0; tcrypt_kdf[i].name; i++) { + if (!(params->flags & CRYPT_TCRYPT_LEGACY_MODES) && tcrypt_kdf[i].legacy) + continue; + if (!(params->flags & CRYPT_TCRYPT_VERA_MODES) && tcrypt_kdf[i].veracrypt) + continue; + if ((params->flags & CRYPT_TCRYPT_VERA_MODES) && params->veracrypt_pim) { + /* Do not try TrueCrypt modes if we have PIM value */ + if (!tcrypt_kdf[i].veracrypt) + continue; + /* adjust iterations to given PIM cmdline parameter */ + iterations = tcrypt_kdf[i].veracrypt_pim_const + + (tcrypt_kdf[i].veracrypt_pim_mult * params->veracrypt_pim); + } else + iterations = tcrypt_kdf[i].iterations; + + /* Derive header key */ + log_dbg(cd, "TCRYPT: trying KDF: %s-%s-%d%s.", + tcrypt_kdf[i].name, tcrypt_kdf[i].hash, tcrypt_kdf[i].iterations, + params->veracrypt_pim && tcrypt_kdf[i].veracrypt ? "-PIM" : ""); + r = crypt_pbkdf(tcrypt_kdf[i].name, tcrypt_kdf[i].hash, + (char*)pwd, passphrase_size, + hdr->salt, TCRYPT_HDR_SALT_LEN, + key, TCRYPT_HDR_KEY_LEN, + iterations, 0, 0); + if (r < 0) { + log_verbose(cd, _("PBKDF2 hash algorithm %s not available, skipping."), + tcrypt_kdf[i].hash); + continue; + } + + /* Decrypt header */ + r = TCRYPT_decrypt_hdr(cd, hdr, key, params->flags); + if (r == -ENOENT) { + skipped++; + r = -EPERM; + } + if (r != -EPERM) + break; + } + + if ((r < 0 && r != -EPERM && skipped && skipped == i) || r == -ENOTSUP) { + log_err(cd, _("Required kernel crypto interface not available.")); +#ifdef ENABLE_AF_ALG + log_err(cd, _("Ensure you have algif_skcipher kernel module loaded.")); +#endif + } + if (r < 0) + goto out; + + r = TCRYPT_hdr_from_disk(cd, hdr, params, i, r); + if (!r) { + log_dbg(cd, "TCRYPT: Magic: %s, Header version: %d, req. %d, sector %d" + ", mk_offset %" PRIu64 ", hidden_size %" PRIu64 + ", volume size %" PRIu64, tcrypt_kdf[i].veracrypt ? + VCRYPT_HDR_MAGIC : TCRYPT_HDR_MAGIC, + (int)hdr->d.version, (int)hdr->d.version_tc, (int)hdr->d.sector_size, + hdr->d.mk_offset, hdr->d.hidden_volume_size, hdr->d.volume_size); + log_dbg(cd, "TCRYPT: Header cipher %s-%s, key size %zu", + params->cipher, params->mode, params->key_size); + } +out: + crypt_safe_memzero(pwd, TCRYPT_KEY_POOL_LEN); + if (key) + crypt_safe_memzero(key, TCRYPT_HDR_KEY_LEN); + free(key); + return r; +} + +int TCRYPT_read_phdr(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params) +{ + struct device *base_device = NULL, *device = crypt_metadata_device(cd); + ssize_t hdr_size = sizeof(struct tcrypt_phdr); + char *base_device_path; + int devfd, r; + + assert(sizeof(struct tcrypt_phdr) == 512); + + log_dbg(cd, "Reading TCRYPT header of size %zu bytes from device %s.", + hdr_size, device_path(device)); + + if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER && + crypt_dev_is_partition(device_path(device))) { + base_device_path = crypt_get_base_device(device_path(device)); + + log_dbg(cd, "Reading TCRYPT system header from device %s.", base_device_path ?: "?"); + if (!base_device_path) + return -EINVAL; + + r = device_alloc(cd, &base_device, base_device_path); + free(base_device_path); + if (r < 0) + return r; + devfd = device_open(cd, base_device, O_RDONLY); + } else + devfd = device_open(cd, device, O_RDONLY); + + if (devfd < 0) { + device_free(cd, base_device); + log_err(cd, _("Cannot open device %s."), device_path(device)); + return -EINVAL; + } + + r = -EIO; + if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) { + if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr, hdr_size, + TCRYPT_HDR_SYSTEM_OFFSET) == hdr_size) { + r = TCRYPT_init_hdr(cd, hdr, params); + } + } else if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) { + if (params->flags & CRYPT_TCRYPT_BACKUP_HEADER) { + if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr, hdr_size, + TCRYPT_HDR_HIDDEN_OFFSET_BCK) == hdr_size) + r = TCRYPT_init_hdr(cd, hdr, params); + } else { + if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr, hdr_size, + TCRYPT_HDR_HIDDEN_OFFSET) == hdr_size) + r = TCRYPT_init_hdr(cd, hdr, params); + if (r && read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr, hdr_size, + TCRYPT_HDR_HIDDEN_OFFSET_OLD) == hdr_size) + r = TCRYPT_init_hdr(cd, hdr, params); + } + } else if (params->flags & CRYPT_TCRYPT_BACKUP_HEADER) { + if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr, hdr_size, + TCRYPT_HDR_OFFSET_BCK) == hdr_size) + r = TCRYPT_init_hdr(cd, hdr, params); + } else if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr, hdr_size, 0) == hdr_size) + r = TCRYPT_init_hdr(cd, hdr, params); + + device_free(cd, base_device); + if (r < 0) + memset(hdr, 0, sizeof (*hdr)); + return r; +} + +static struct tcrypt_algs *TCRYPT_get_algs(const char *cipher, const char *mode) +{ + int i; + + if (!cipher || !mode) + return NULL; + + for (i = 0; tcrypt_cipher[i].chain_count; i++) + if (!strcmp(tcrypt_cipher[i].long_name, cipher) && + !strcmp(tcrypt_cipher[i].mode, mode)) + return &tcrypt_cipher[i]; + + return NULL; +} + +int TCRYPT_activate(struct crypt_device *cd, + const char *name, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params, + uint32_t flags) +{ + char dm_name[PATH_MAX], dm_dev_name[PATH_MAX], cipher_spec[MAX_CIPHER_LEN*2+1]; + char *part_path; + unsigned int i; + int r; + uint32_t req_flags, dmc_flags; + struct tcrypt_algs *algs; + enum devcheck device_check; + uint64_t offset = crypt_get_data_offset(cd); + struct volume_key *vk = NULL; + struct device *ptr_dev = crypt_data_device(cd), *device = NULL, *part_device = NULL; + struct crypt_dm_active_device dmd = { + .flags = flags + }; + + if (!hdr->d.version) { + log_dbg(cd, "TCRYPT: this function is not supported without encrypted header load."); + return -ENOTSUP; + } + + if (hdr->d.sector_size % SECTOR_SIZE) { + log_err(cd, _("Activation is not supported for %d sector size."), + hdr->d.sector_size); + return -ENOTSUP; + } + + if (strstr(params->mode, "-tcrypt")) { + log_err(cd, _("Kernel does not support activation for this TCRYPT legacy mode.")); + return -ENOTSUP; + } + + if (strstr(params->mode, "-tcw")) + req_flags = DM_TCW_SUPPORTED; + else + req_flags = DM_PLAIN64_SUPPORTED; + + algs = TCRYPT_get_algs(params->cipher, params->mode); + if (!algs) + return -EINVAL; + + if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) + dmd.size = 0; + else if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) + dmd.size = hdr->d.hidden_volume_size / SECTOR_SIZE; + else + dmd.size = hdr->d.volume_size / SECTOR_SIZE; + + if (dmd.flags & CRYPT_ACTIVATE_SHARED) + device_check = DEV_OK; + else + device_check = DEV_EXCL; + + if ((params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) && + !crypt_dev_is_partition(device_path(crypt_data_device(cd)))) { + part_path = crypt_get_partition_device(device_path(crypt_data_device(cd)), + crypt_get_data_offset(cd), dmd.size); + if (part_path) { + if (!device_alloc(cd, &part_device, part_path)) { + log_verbose(cd, _("Activating TCRYPT system encryption for partition %s."), + part_path); + ptr_dev = part_device; + offset = 0; + } + free(part_path); + } else + /* + * System encryption use the whole device mapping, there can + * be active partitions. + */ + device_check = DEV_OK; + } + + r = device_block_adjust(cd, ptr_dev, device_check, + offset, &dmd.size, &dmd.flags); + if (r) + goto out; + + /* From here, key size for every cipher must be the same */ + vk = crypt_alloc_volume_key(algs->cipher[0].key_size + + algs->cipher[0].key_extra_size, NULL); + if (!vk) { + r = -ENOMEM; + goto out; + } + + for (i = algs->chain_count; i > 0; i--) { + if (i == 1) { + dm_name[sizeof(dm_name)-1] = '\0'; + strncpy(dm_name, name, sizeof(dm_name)-1); + dmd.flags = flags; + } else { + snprintf(dm_name, sizeof(dm_name), "%s_%d", name, i-1); + dmd.flags = flags | CRYPT_ACTIVATE_PRIVATE; + } + + TCRYPT_copy_key(&algs->cipher[i-1], algs->mode, + vk->key, hdr->d.keys); + + if (algs->chain_count != i) { + snprintf(dm_dev_name, sizeof(dm_dev_name), "%s/%s_%d", + dm_get_dir(), name, i); + r = device_alloc(cd, &device, dm_dev_name); + if (r) + break; + ptr_dev = device; + offset = 0; + } + + r = snprintf(cipher_spec, sizeof(cipher_spec), "%s-%s", algs->cipher[i-1].name, algs->mode); + if (r < 0 || (size_t)r >= sizeof(cipher_spec)) { + r = -ENOMEM; + break; + } + + r = dm_crypt_target_set(&dmd.segment, 0, dmd.size, ptr_dev, vk, + cipher_spec, crypt_get_iv_offset(cd), offset, + crypt_get_integrity(cd), + crypt_get_integrity_tag_size(cd), + crypt_get_sector_size(cd)); + if (r) + break; + + log_dbg(cd, "Trying to activate TCRYPT device %s using cipher %s.", + dm_name, dmd.segment.u.crypt.cipher); + r = dm_create_device(cd, dm_name, CRYPT_TCRYPT, &dmd); + + dm_targets_free(cd, &dmd); + device_free(cd, device); + device = NULL; + + if (r) + break; + } + + if (r < 0 && + (dm_flags(cd, DM_CRYPT, &dmc_flags) || ((dmc_flags & req_flags) != req_flags))) { + log_err(cd, _("Kernel does not support TCRYPT compatible mapping.")); + r = -ENOTSUP; + } + +out: + crypt_free_volume_key(vk); + device_free(cd, device); + device_free(cd, part_device); + return r; +} + +static int TCRYPT_remove_one(struct crypt_device *cd, const char *name, + const char *base_uuid, int index, uint32_t flags) +{ + struct crypt_dm_active_device dmd; + char dm_name[PATH_MAX]; + int r; + + if (snprintf(dm_name, sizeof(dm_name), "%s_%d", name, index) < 0) + return -ENOMEM; + + r = dm_status_device(cd, dm_name); + if (r < 0) + return r; + + r = dm_query_device(cd, dm_name, DM_ACTIVE_UUID, &dmd); + if (!r && !strncmp(dmd.uuid, base_uuid, strlen(base_uuid))) + r = dm_remove_device(cd, dm_name, flags); + + free(CONST_CAST(void*)dmd.uuid); + return r; +} + +int TCRYPT_deactivate(struct crypt_device *cd, const char *name, uint32_t flags) +{ + struct crypt_dm_active_device dmd; + int r; + + r = dm_query_device(cd, name, DM_ACTIVE_UUID, &dmd); + if (r < 0) + return r; + if (!dmd.uuid) + return -EINVAL; + + r = dm_remove_device(cd, name, flags); + if (r < 0) + goto out; + + r = TCRYPT_remove_one(cd, name, dmd.uuid, 1, flags); + if (r < 0) + goto out; + + r = TCRYPT_remove_one(cd, name, dmd.uuid, 2, flags); +out: + free(CONST_CAST(void*)dmd.uuid); + return (r == -ENODEV) ? 0 : r; +} + +static int TCRYPT_status_one(struct crypt_device *cd, const char *name, + const char *base_uuid, int index, + size_t *key_size, char *cipher, + struct tcrypt_phdr *tcrypt_hdr, + struct device **device) +{ + struct crypt_dm_active_device dmd; + struct dm_target *tgt = &dmd.segment; + char dm_name[PATH_MAX], *c; + int r; + + if (snprintf(dm_name, sizeof(dm_name), "%s_%d", name, index) < 0) + return -ENOMEM; + + r = dm_status_device(cd, dm_name); + if (r < 0) + return r; + + r = dm_query_device(cd, dm_name, DM_ACTIVE_DEVICE | + DM_ACTIVE_UUID | + DM_ACTIVE_CRYPT_CIPHER | + DM_ACTIVE_CRYPT_KEYSIZE, &dmd); + if (r < 0) + return r; + if (!single_segment(&dmd) || tgt->type != DM_CRYPT) { + r = -ENOTSUP; + goto out; + } + + r = 0; + + if (!strncmp(dmd.uuid, base_uuid, strlen(base_uuid))) { + if ((c = strchr(tgt->u.crypt.cipher, '-'))) + *c = '\0'; + strcat(cipher, "-"); + strncat(cipher, tgt->u.crypt.cipher, MAX_CIPHER_LEN); + *key_size += tgt->u.crypt.vk->keylength; + tcrypt_hdr->d.mk_offset = tgt->u.crypt.offset * SECTOR_SIZE; + device_free(cd, *device); + MOVE_REF(*device, tgt->data_device); + } else + r = -ENODEV; +out: + dm_targets_free(cd, &dmd); + free(CONST_CAST(void*)dmd.uuid); + return r; +} + +int TCRYPT_init_by_name(struct crypt_device *cd, const char *name, + const char *uuid, + const struct dm_target *tgt, + struct device **device, + struct crypt_params_tcrypt *tcrypt_params, + struct tcrypt_phdr *tcrypt_hdr) +{ + struct tcrypt_algs *algs; + char cipher[MAX_CIPHER_LEN * 4], mode[MAX_CIPHER_LEN+1], *tmp; + size_t key_size; + int r; + + memset(tcrypt_params, 0, sizeof(*tcrypt_params)); + memset(tcrypt_hdr, 0, sizeof(*tcrypt_hdr)); + tcrypt_hdr->d.sector_size = SECTOR_SIZE; + tcrypt_hdr->d.mk_offset = tgt->u.crypt.offset * SECTOR_SIZE; + + strncpy(cipher, tgt->u.crypt.cipher, MAX_CIPHER_LEN); + tmp = strchr(cipher, '-'); + if (!tmp) + return -EINVAL; + *tmp = '\0'; + mode[MAX_CIPHER_LEN] = '\0'; + strncpy(mode, ++tmp, MAX_CIPHER_LEN); + + key_size = tgt->u.crypt.vk->keylength; + r = TCRYPT_status_one(cd, name, uuid, 1, &key_size, + cipher, tcrypt_hdr, device); + if (!r) + r = TCRYPT_status_one(cd, name, uuid, 2, &key_size, + cipher, tcrypt_hdr, device); + + if (r < 0 && r != -ENODEV) + return r; + + algs = TCRYPT_get_algs(cipher, mode); + if (!algs || key_size != algs->chain_key_size) + return -EINVAL; + + tcrypt_params->key_size = algs->chain_key_size; + tcrypt_params->cipher = algs->long_name; + tcrypt_params->mode = algs->mode; + return 0; +} + +uint64_t TCRYPT_get_data_offset(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params) +{ + uint64_t size; + + /* No real header loaded, initialized by active device */ + if (!hdr->d.version) + goto hdr_offset; + + /* Mapping through whole device, not partition! */ + if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) { + if (crypt_dev_is_partition(device_path(crypt_data_device(cd)))) + return 0; + goto hdr_offset; + } + + if (params->mode && !strncmp(params->mode, "xts", 3)) { + if (hdr->d.version < 3) + return 1; + + if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) { + if (hdr->d.version > 3) + return (hdr->d.mk_offset / SECTOR_SIZE); + if (device_size(crypt_metadata_device(cd), &size) < 0) + return 0; + return (size - hdr->d.hidden_volume_size + + (TCRYPT_HDR_HIDDEN_OFFSET_OLD)) / SECTOR_SIZE; + } + goto hdr_offset; + } + + if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) { + if (device_size(crypt_metadata_device(cd), &size) < 0) + return 0; + return (size - hdr->d.hidden_volume_size + + (TCRYPT_HDR_HIDDEN_OFFSET_OLD)) / SECTOR_SIZE; + } + +hdr_offset: + return hdr->d.mk_offset / SECTOR_SIZE; +} + +uint64_t TCRYPT_get_iv_offset(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params) +{ + uint64_t iv_offset; + + if (params->mode && !strncmp(params->mode, "xts", 3)) + iv_offset = TCRYPT_get_data_offset(cd, hdr, params); + else if (params->mode && !strncmp(params->mode, "lrw", 3)) + iv_offset = 0; + else + iv_offset = hdr->d.mk_offset / SECTOR_SIZE; + + if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) + iv_offset += crypt_dev_partition_offset(device_path(crypt_data_device(cd))); + + return iv_offset; +} + +int TCRYPT_get_volume_key(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params, + struct volume_key **vk) +{ + struct tcrypt_algs *algs; + unsigned int i, key_index; + + if (!hdr->d.version) { + log_err(cd, _("This function is not supported without TCRYPT header load.")); + return -ENOTSUP; + } + + algs = TCRYPT_get_algs(params->cipher, params->mode); + if (!algs) + return -EINVAL; + + *vk = crypt_alloc_volume_key(params->key_size, NULL); + if (!*vk) + return -ENOMEM; + + for (i = 0, key_index = 0; i < algs->chain_count; i++) { + TCRYPT_copy_key(&algs->cipher[i], algs->mode, + &(*vk)->key[key_index], hdr->d.keys); + key_index += algs->cipher[i].key_size; + } + + return 0; +} + +int TCRYPT_dump(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params) +{ + log_std(cd, "%s header information for %s\n", + hdr->d.magic[0] == 'T' ? "TCRYPT" : "VERACRYPT", + device_path(crypt_metadata_device(cd))); + if (hdr->d.version) { + log_std(cd, "Version: \t%d\n", hdr->d.version); + log_std(cd, "Driver req.:\t%x.%x\n", hdr->d.version_tc >> 8, + hdr->d.version_tc & 0xFF); + + log_std(cd, "Sector size:\t%" PRIu32 "\n", hdr->d.sector_size); + log_std(cd, "MK offset:\t%" PRIu64 "\n", hdr->d.mk_offset); + log_std(cd, "PBKDF2 hash:\t%s\n", params->hash_name); + } + log_std(cd, "Cipher chain:\t%s\n", params->cipher); + log_std(cd, "Cipher mode:\t%s\n", params->mode); + log_std(cd, "MK bits: \t%zu\n", params->key_size * 8); + return 0; +} diff --git a/lib/tcrypt/tcrypt.h b/lib/tcrypt/tcrypt.h new file mode 100644 index 0000000..ff12cbd --- /dev/null +++ b/lib/tcrypt/tcrypt.h @@ -0,0 +1,121 @@ +/* + * TCRYPT (TrueCrypt-compatible) header definition + * + * Copyright (C) 2012-2021 Red Hat, Inc. All rights reserved. + * Copyright (C) 2012-2021 Milan Broz + * + * This file is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This file is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef _CRYPTSETUP_TCRYPT_H +#define _CRYPTSETUP_TCRYPT_H + +#include <stdint.h> + +#define TCRYPT_HDR_SALT_LEN 64 +#define TCRYPT_HDR_IV_LEN 16 +#define TCRYPT_HDR_LEN 448 +#define TCRYPT_HDR_KEY_LEN 192 +#define TCRYPT_HDR_MAGIC "TRUE" +#define VCRYPT_HDR_MAGIC "VERA" +#define TCRYPT_HDR_MAGIC_LEN 4 + +#define TCRYPT_HDR_HIDDEN_OFFSET_OLD -1536 +#define TCRYPT_HDR_HIDDEN_OFFSET 65536 + +#define TCRYPT_HDR_HIDDEN_OFFSET_BCK -65536 +#define TCRYPT_HDR_OFFSET_BCK -131072 + +#define TCRYPT_HDR_SYSTEM_OFFSET 31744 + +#define TCRYPT_LRW_IKEY_LEN 16 +#define TCRYPT_KEY_POOL_LEN 64 +#define VCRYPT_KEY_POOL_LEN 128 +#define TCRYPT_KEYFILE_LEN 1048576 + +#define TCRYPT_HDR_FLAG_SYSTEM (1 << 0) +#define TCRYPT_HDR_FLAG_NONSYSTEM (1 << 1) + +struct tcrypt_phdr { + char salt[TCRYPT_HDR_SALT_LEN]; + + /* encrypted part, TCRYPT_HDR_LEN bytes */ + union { + struct __attribute__((__packed__)) { + char magic[TCRYPT_HDR_MAGIC_LEN]; + uint16_t version; + uint16_t version_tc; + uint32_t keys_crc32; + uint64_t _reserved1[2]; /* data/header ctime */ + uint64_t hidden_volume_size; + uint64_t volume_size; + uint64_t mk_offset; + uint64_t mk_size; + uint32_t flags; + uint32_t sector_size; + uint8_t _reserved2[120]; + uint32_t header_crc32; + char keys[256]; + } d; + char e[TCRYPT_HDR_LEN]; + }; +} __attribute__((__packed__)); + +struct crypt_device; +struct crypt_params_tcrypt; +struct crypt_dm_active_device; +struct dm_target; +struct volume_key; +struct device; + +int TCRYPT_read_phdr(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params); + +int TCRYPT_init_by_name(struct crypt_device *cd, const char *name, + const char *uuid, + const struct dm_target *tgt, + struct device **device, + struct crypt_params_tcrypt *tcrypt_params, + struct tcrypt_phdr *tcrypt_hdr); + +int TCRYPT_activate(struct crypt_device *cd, + const char *name, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params, + uint32_t flags); + +int TCRYPT_deactivate(struct crypt_device *cd, + const char *name, + uint32_t flags); + +uint64_t TCRYPT_get_data_offset(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params); + +uint64_t TCRYPT_get_iv_offset(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params); + +int TCRYPT_get_volume_key(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params, + struct volume_key **vk); + +int TCRYPT_dump(struct crypt_device *cd, + struct tcrypt_phdr *hdr, + struct crypt_params_tcrypt *params); + +#endif |