/* Try to open a particular key slot */
static int LUKS_open_key(unsigned int keyIndex,
const char *password,
size_t passwordLen,
struct luks_phdr *hdr,
struct volume_key *vk,
struct crypt_device *ctx)
{
crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyIndex);
struct volume_key *derived_key;
char *AfKey;
size_t AFEKSize;
int r;
log_dbg("Trying to open key slot %d [%s].", keyIndex,
dbg_slot_state(ki));
if (ki < CRYPT_SLOT_ACTIVE)
return -ENOENT;
derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
if (!derived_key)
return -ENOMEM;
assert(vk->keylength == hdr->keyBytes);
AFEKSize = AF_split_sectors(vk->keylength, hdr->keyblock[keyIndex].stripes) * SECTOR_SIZE;
AfKey = crypt_safe_alloc(AFEKSize);
if (!AfKey) {
r = -ENOMEM;
goto out;
}
r = crypt_pbkdf("pbkdf2", hdr->hashSpec, password, passwordLen,
hdr->keyblock[keyIndex].passwordSalt, LUKS_SALTSIZE,
derived_key->key, hdr->keyBytes,
hdr->keyblock[keyIndex].passwordIterations);
if (r < 0)
goto out;
log_dbg("Reading key slot %d area.", keyIndex);
r = LUKS_decrypt_from_storage(AfKey,
AFEKSize,
hdr->cipherName, hdr->cipherMode,
derived_key,
hdr->keyblock[keyIndex].keyMaterialOffset,
ctx);
if (r < 0)
goto out;
r = AF_merge(AfKey,vk->key,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
if (r < 0)
goto out;
r = LUKS_verify_volume_key(hdr, vk);
if (!r)
log_verbose(ctx, _("Key slot %d unlocked.\n"), keyIndex);
out:
crypt_safe_free(AfKey);
crypt_free_volume_key(derived_key);
return r;
}
/* Check whether a volume key is invalid. */
int LUKS_verify_volume_key(const struct luks_phdr *hdr,
const struct volume_key *vk)
{
char checkHashBuf[LUKS_DIGESTSIZE];
if (crypt_pbkdf("pbkdf2", hdr->hashSpec, vk->key, vk->keylength,
hdr->mkDigestSalt, LUKS_SALTSIZE,
checkHashBuf, LUKS_DIGESTSIZE,
hdr->mkDigestIterations) < 0)
return -EINVAL;
if (memcmp(checkHashBuf, hdr->mkDigest, LUKS_DIGESTSIZE))
return -EPERM;
return 0;
}
int LUKS_set_key(unsigned int keyIndex,
const char *password, size_t passwordLen,
struct luks_phdr *hdr, struct volume_key *vk,
uint32_t iteration_time_ms,
uint64_t *PBKDF2_per_sec,
struct crypt_device *ctx)
{
struct volume_key *derived_key;
char *AfKey = NULL;
size_t AFEKSize;
uint64_t PBKDF2_temp;
int r;
if(hdr->keyblock[keyIndex].active != LUKS_KEY_DISABLED) {
log_err(ctx, _("Key slot %d active, purge first.\n"), keyIndex);
return -EINVAL;
}
/* LUKS keyslot has always at least 4000 stripes accoding to specification */
if(hdr->keyblock[keyIndex].stripes < 4000) {
log_err(ctx, _("Key slot %d material includes too few stripes. Header manipulation?\n"),
keyIndex);
return -EINVAL;
}
log_dbg("Calculating data for key slot %d", keyIndex);
r = crypt_benchmark_kdf(ctx, "pbkdf2", hdr->hashSpec,
"foo", 3, "bar", 3, PBKDF2_per_sec);
if (r < 0) {
log_err(ctx, _("Not compatible PBKDF2 options (using hash algorithm %s).\n"),
hdr->hashSpec);
return r;
}
/*
* Avoid floating point operation
* Final iteration count is at least LUKS_SLOT_ITERATIONS_MIN
*/
PBKDF2_temp = (*PBKDF2_per_sec / 2) * (uint64_t)iteration_time_ms;
PBKDF2_temp /= 1024;
if (PBKDF2_temp > UINT32_MAX)
PBKDF2_temp = UINT32_MAX;
hdr->keyblock[keyIndex].passwordIterations = at_least((uint32_t)PBKDF2_temp,
LUKS_SLOT_ITERATIONS_MIN);
log_dbg("Key slot %d use %" PRIu32 " password iterations.", keyIndex, hdr->keyblock[keyIndex].passwordIterations);
derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
if (!derived_key)
return -ENOMEM;
r = crypt_random_get(ctx, hdr->keyblock[keyIndex].passwordSalt,
LUKS_SALTSIZE, CRYPT_RND_SALT);
if (r < 0)
goto out;
r = crypt_pbkdf("pbkdf2", hdr->hashSpec, password, passwordLen,
hdr->keyblock[keyIndex].passwordSalt, LUKS_SALTSIZE,
derived_key->key, hdr->keyBytes,
hdr->keyblock[keyIndex].passwordIterations);
if (r < 0)
goto out;
/*
* AF splitting, the masterkey stored in vk->key is split to AfKey
*/
assert(vk->keylength == hdr->keyBytes);
AFEKSize = AF_split_sectors(vk->keylength, hdr->keyblock[keyIndex].stripes) * SECTOR_SIZE;
AfKey = crypt_safe_alloc(AFEKSize);
if (!AfKey) {
r = -ENOMEM;
goto out;
}
log_dbg("Using hash %s for AF in key slot %d, %d stripes",
hdr->hashSpec, keyIndex, hdr->keyblock[keyIndex].stripes);
r = AF_split(vk->key,AfKey,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
if (r < 0)
goto out;
log_dbg("Updating key slot %d [0x%04x] area.", keyIndex,
hdr->keyblock[keyIndex].keyMaterialOffset << 9);
/* Encryption via dm */
r = LUKS_encrypt_to_storage(AfKey,
AFEKSize,
hdr->cipherName, hdr->cipherMode,
derived_key,
hdr->keyblock[keyIndex].keyMaterialOffset,
ctx);
if (r < 0)
goto out;
/* Mark the key as active in phdr */
r = LUKS_keyslot_set(hdr, (int)keyIndex, 1);
if (r < 0)
goto out;
r = LUKS_write_phdr(hdr, ctx);
if (r < 0)
goto out;
r = 0;
out:
crypt_safe_free(AfKey);
crypt_free_volume_key(derived_key);
return r;
}
int LUKS_generate_phdr(struct luks_phdr *header,
const struct volume_key *vk,
const char *cipherName, const char *cipherMode, const char *hashSpec,
const char *uuid, unsigned int stripes,
unsigned int alignPayload,
unsigned int alignOffset,
uint32_t iteration_time_ms,
uint64_t *PBKDF2_per_sec,
int detached_metadata_device,
struct crypt_device *ctx)
{
unsigned int i = 0, hdr_sectors = LUKS_device_sectors(vk->keylength);
size_t blocksPerStripeSet, currentSector;
int r;
uuid_t partitionUuid;
char luksMagic[] = LUKS_MAGIC;
/* For separate metadata device allow zero alignment */
if (alignPayload == 0 && !detached_metadata_device)
alignPayload = DEFAULT_DISK_ALIGNMENT / SECTOR_SIZE;
if (alignPayload && detached_metadata_device && alignPayload < hdr_sectors) {
log_err(ctx, _("Data offset for detached LUKS header must be "
"either 0 or higher than header size (%d sectors).\n"),
hdr_sectors);
return -EINVAL;
}
if (crypt_hmac_size(hashSpec) < LUKS_DIGESTSIZE) {
log_err(ctx, _("Requested LUKS hash %s is not supported.\n"), hashSpec);
return -EINVAL;
}
if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
log_err(ctx, _("Wrong LUKS UUID format provided.\n"));
return -EINVAL;
}
if (!uuid)
uuid_generate(partitionUuid);
memset(header,0,sizeof(struct luks_phdr));
/* Set Magic */
memcpy(header->magic,luksMagic,LUKS_MAGIC_L);
header->version=1;
strncpy(header->cipherName,cipherName,LUKS_CIPHERNAME_L);
strncpy(header->cipherMode,cipherMode,LUKS_CIPHERMODE_L);
strncpy(header->hashSpec,hashSpec,LUKS_HASHSPEC_L);
header->keyBytes=vk->keylength;
LUKS_fix_header_compatible(header);
r = LUKS_check_cipher(header, ctx);
if (r < 0)
return r;
log_dbg("Generating LUKS header version %d using hash %s, %s, %s, MK %d bytes",
header->version, header->hashSpec ,header->cipherName, header->cipherMode,
header->keyBytes);
r = crypt_random_get(ctx, header->mkDigestSalt, LUKS_SALTSIZE, CRYPT_RND_SALT);
if(r < 0) {
log_err(ctx, _("Cannot create LUKS header: reading random salt failed.\n"));
return r;
}
r = crypt_benchmark_kdf(ctx, "pbkdf2", header->hashSpec,
"foo", 3, "bar", 3, PBKDF2_per_sec);
if (r < 0) {
log_err(ctx, _("Not compatible PBKDF2 options (using hash algorithm %s).\n"),
header->hashSpec);
return r;
}
/* Compute master key digest */
iteration_time_ms /= 8;
header->mkDigestIterations = at_least((uint32_t)(*PBKDF2_per_sec/1024) * iteration_time_ms,
LUKS_MKD_ITERATIONS_MIN);
r = crypt_pbkdf("pbkdf2", header->hashSpec, vk->key,vk->keylength,
header->mkDigestSalt, LUKS_SALTSIZE,
header->mkDigest,LUKS_DIGESTSIZE,
header->mkDigestIterations);
if(r < 0) {
log_err(ctx, _("Cannot create LUKS header: header digest failed (using hash %s).\n"),
header->hashSpec);
return r;
}
currentSector = LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE;
blocksPerStripeSet = AF_split_sectors(vk->keylength, stripes);
for(i = 0; i < LUKS_NUMKEYS; ++i) {
header->keyblock[i].active = LUKS_KEY_DISABLED;
header->keyblock[i].keyMaterialOffset = currentSector;
header->keyblock[i].stripes = stripes;
currentSector = size_round_up(currentSector + blocksPerStripeSet,
LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
}
if (detached_metadata_device) {
/* for separate metadata device use alignPayload directly */
header->payloadOffset = alignPayload;
} else {
/* alignOffset - offset from natural device alignment provided by topology info */
currentSector = size_round_up(currentSector, alignPayload);
header->payloadOffset = currentSector + alignOffset;
}
uuid_unparse(partitionUuid, header->uuid);
log_dbg("Data offset %d, UUID %s, digest iterations %" PRIu32,
header->payloadOffset, header->uuid, header->mkDigestIterations);
return 0;
}
int LUKS_set_key(unsigned int keyIndex,
const char *password, size_t passwordLen,
struct luks_phdr *hdr, struct volume_key *vk,
struct crypt_device *ctx)
{
struct volume_key *derived_key;
char *AfKey = NULL;
size_t AFEKSize;
struct crypt_pbkdf_type *pbkdf;
int r;
if(hdr->keyblock[keyIndex].active != LUKS_KEY_DISABLED) {
log_err(ctx, _("Key slot %d active, purge first."), keyIndex);
return -EINVAL;
}
/* LUKS keyslot has always at least 4000 stripes according to specification */
if(hdr->keyblock[keyIndex].stripes < 4000) {
log_err(ctx, _("Key slot %d material includes too few stripes. Header manipulation?"),
keyIndex);
return -EINVAL;
}
log_dbg("Calculating data for key slot %d", keyIndex);
pbkdf = crypt_get_pbkdf(ctx);
r = crypt_benchmark_pbkdf_internal(ctx, pbkdf, vk->keylength);
if (r < 0)
return r;
assert(pbkdf->iterations);
/*
* Final iteration count is at least LUKS_SLOT_ITERATIONS_MIN
*/
hdr->keyblock[keyIndex].passwordIterations =
at_least(pbkdf->iterations, LUKS_SLOT_ITERATIONS_MIN);
log_dbg("Key slot %d use %" PRIu32 " password iterations.", keyIndex,
hdr->keyblock[keyIndex].passwordIterations);
derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
if (!derived_key)
return -ENOMEM;
r = crypt_random_get(ctx, hdr->keyblock[keyIndex].passwordSalt,
LUKS_SALTSIZE, CRYPT_RND_SALT);
if (r < 0)
goto out;
r = crypt_pbkdf(CRYPT_KDF_PBKDF2, hdr->hashSpec, password, passwordLen,
hdr->keyblock[keyIndex].passwordSalt, LUKS_SALTSIZE,
derived_key->key, hdr->keyBytes,
hdr->keyblock[keyIndex].passwordIterations, 0, 0);
if (r < 0)
goto out;
/*
* AF splitting, the masterkey stored in vk->key is split to AfKey
*/
assert(vk->keylength == hdr->keyBytes);
AFEKSize = AF_split_sectors(vk->keylength, hdr->keyblock[keyIndex].stripes) * SECTOR_SIZE;
AfKey = crypt_safe_alloc(AFEKSize);
if (!AfKey) {
r = -ENOMEM;
goto out;
}
log_dbg("Using hash %s for AF in key slot %d, %d stripes",
hdr->hashSpec, keyIndex, hdr->keyblock[keyIndex].stripes);
r = AF_split(vk->key,AfKey,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
if (r < 0)
goto out;
log_dbg("Updating key slot %d [0x%04x] area.", keyIndex,
hdr->keyblock[keyIndex].keyMaterialOffset << 9);
/* Encryption via dm */
r = LUKS_encrypt_to_storage(AfKey,
AFEKSize,
hdr->cipherName, hdr->cipherMode,
derived_key,
hdr->keyblock[keyIndex].keyMaterialOffset,
ctx);
if (r < 0)
goto out;
/* Mark the key as active in phdr */
r = LUKS_keyslot_set(hdr, (int)keyIndex, 1);
if (r < 0)
goto out;
r = LUKS_write_phdr(hdr, ctx);
if (r < 0)
goto out;
r = 0;
out:
crypt_safe_free(AfKey);
crypt_free_volume_key(derived_key);
return r;
}
static int TCRYPT_init_hdr(struct crypt_device *cd,
struct tcrypt_phdr *hdr,
struct crypt_params_tcrypt *params)
{
unsigned char pwd[TCRYPT_KEY_POOL_LEN] = {};
size_t passphrase_size;
char *key;
unsigned int i, skipped = 0;
int r = -EPERM;
if (posix_memalign((void*)&key, crypt_getpagesize(), TCRYPT_HDR_KEY_LEN))
return -ENOMEM;
if (params->keyfiles_count)
passphrase_size = TCRYPT_KEY_POOL_LEN;
else
passphrase_size = params->passphrase_size;
if (params->passphrase_size > TCRYPT_KEY_POOL_LEN) {
log_err(cd, _("Maximum TCRYPT passphrase length (%d) exceeded.\n"),
TCRYPT_KEY_POOL_LEN);
goto out;
}
/* Calculate pool content from keyfiles */
for (i = 0; i < params->keyfiles_count; i++) {
r = TCRYPT_pool_keyfile(cd, pwd, params->keyfiles[i]);
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;
/* Derive header key */
log_dbg("TCRYPT: trying KDF: %s-%s-%d.",
tcrypt_kdf[i].name, tcrypt_kdf[i].hash, tcrypt_kdf[i].iterations);
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,
tcrypt_kdf[i].iterations);
if (r < 0 && crypt_hash_size(tcrypt_kdf[i].hash) < 0) {
log_verbose(cd, _("PBKDF2 hash algorithm %s not available, skipping.\n"),
tcrypt_kdf[i].hash);
continue;
}
if (r < 0)
break;
/* 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.\n"));
#ifdef ENABLE_AF_ALG
log_err(cd, _("Ensure you have algif_skcipher kernel module loaded.\n"));
#endif
}
if (r < 0)
goto out;
r = TCRYPT_hdr_from_disk(hdr, params, i, r);
if (!r) {
log_dbg("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("TCRYPT: Header cipher %s-%s, key size %zu",
params->cipher, params->mode, params->key_size);
}
out:
crypt_memzero(pwd, TCRYPT_KEY_POOL_LEN);
if (key)
crypt_memzero(key, TCRYPT_HDR_KEY_LEN);
free(key);
return r;
}
int LUKS_generate_phdr(struct luks_phdr *header,
const struct volume_key *vk,
const char *cipherName,
const char *cipherMode,
const char *hashSpec,
const char *uuid,
uint64_t data_offset, /* in bytes */
uint64_t align_offset, /* in bytes */
uint64_t required_alignment, /* in bytes */
struct crypt_device *ctx)
{
int i, r;
size_t keyslot_sectors, header_sectors;
uuid_t partitionUuid;
struct crypt_pbkdf_type *pbkdf;
double PBKDF2_temp;
char luksMagic[] = LUKS_MAGIC;
if (data_offset % SECTOR_SIZE || align_offset % SECTOR_SIZE ||
required_alignment % SECTOR_SIZE)
return -EINVAL;
memset(header, 0, sizeof(struct luks_phdr));
keyslot_sectors = AF_split_sectors(vk->keylength, LUKS_STRIPES);
header_sectors = LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE;
for (i = 0; i < LUKS_NUMKEYS; i++) {
header->keyblock[i].active = LUKS_KEY_DISABLED;
header->keyblock[i].keyMaterialOffset = header_sectors;
header->keyblock[i].stripes = LUKS_STRIPES;
header_sectors = size_round_up(header_sectors + keyslot_sectors,
LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
}
/* In sector is now size of all keyslot material space */
/* Data offset has priority */
if (data_offset)
header->payloadOffset = data_offset / SECTOR_SIZE;
else if (required_alignment) {
header->payloadOffset = size_round_up(header_sectors, (required_alignment / SECTOR_SIZE));
header->payloadOffset += (align_offset / SECTOR_SIZE);
} else
header->payloadOffset = 0;
if (header->payloadOffset && header->payloadOffset < header_sectors) {
log_err(ctx, _("Data offset for LUKS header must be "
"either 0 or higher than header size."));
return -EINVAL;
}
if (crypt_hmac_size(hashSpec) < LUKS_DIGESTSIZE) {
log_err(ctx, _("Requested LUKS hash %s is not supported."), hashSpec);
return -EINVAL;
}
if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
log_err(ctx, _("Wrong LUKS UUID format provided."));
return -EINVAL;
}
if (!uuid)
uuid_generate(partitionUuid);
/* Set Magic */
memcpy(header->magic,luksMagic,LUKS_MAGIC_L);
header->version=1;
strncpy(header->cipherName,cipherName,LUKS_CIPHERNAME_L-1);
strncpy(header->cipherMode,cipherMode,LUKS_CIPHERMODE_L-1);
strncpy(header->hashSpec,hashSpec,LUKS_HASHSPEC_L-1);
header->keyBytes=vk->keylength;
LUKS_fix_header_compatible(header);
log_dbg(ctx, "Generating LUKS header version %d using hash %s, %s, %s, MK %d bytes",
header->version, header->hashSpec ,header->cipherName, header->cipherMode,
header->keyBytes);
r = crypt_random_get(ctx, header->mkDigestSalt, LUKS_SALTSIZE, CRYPT_RND_SALT);
if(r < 0) {
log_err(ctx, _("Cannot create LUKS header: reading random salt failed."));
return r;
}
/* Compute master key digest */
pbkdf = crypt_get_pbkdf(ctx);
r = crypt_benchmark_pbkdf_internal(ctx, pbkdf, vk->keylength);
if (r < 0)
return r;
assert(pbkdf->iterations);
PBKDF2_temp = (double)pbkdf->iterations * LUKS_MKD_ITERATIONS_MS / pbkdf->time_ms;
if (PBKDF2_temp > (double)UINT32_MAX)
return -EINVAL;
header->mkDigestIterations = at_least((uint32_t)PBKDF2_temp, LUKS_MKD_ITERATIONS_MIN);
r = crypt_pbkdf(CRYPT_KDF_PBKDF2, header->hashSpec, vk->key,vk->keylength,
header->mkDigestSalt, LUKS_SALTSIZE,
header->mkDigest,LUKS_DIGESTSIZE,
header->mkDigestIterations, 0, 0);
if (r < 0) {
log_err(ctx, _("Cannot create LUKS header: header digest failed (using hash %s)."),
header->hashSpec);
return r;
}
uuid_unparse(partitionUuid, header->uuid);
log_dbg(ctx, "Data offset %d, UUID %s, digest iterations %" PRIu32,
header->payloadOffset, header->uuid, header->mkDigestIterations);
return 0;
}
