/*
* TCRYPT (TrueCrypt-compatible) and VeraCrypt volume handling
*
* Copyright (C) 2012-2020 Red Hat, Inc. All rights reserved.
* Copyright (C) 2012-2020 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 && 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 (hdr->d.sector_size == 0)
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 / hdr->d.sector_size;
else
dmd.size = hdr->d.volume_size / hdr->d.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_metadata_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 / hdr->d.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)) / hdr->d.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)) / hdr->d.sector_size;
}
hdr_offset:
return hdr->d.mk_offset / hdr->d.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 / hdr->d.sector_size;
if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER)
iv_offset += crypt_dev_partition_offset(device_path(crypt_metadata_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;
}