/* Get size of struct luks_phdr with all keyslots material space */
static size_t LUKS_device_sectors(size_t keyLen)
{
size_t keyslot_sectors, sector;
int i;
keyslot_sectors = AF_split_sectors(keyLen, LUKS_STRIPES);
sector = LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE;
for (i = 0; i < LUKS_NUMKEYS; i++) {
sector = size_round_up(sector, LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
sector += keyslot_sectors;
}
return sector;
}
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_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;
}
int LUKS_hdr_backup(const char *backup_file, struct crypt_device *ctx)
{
struct device *device = crypt_metadata_device(ctx);
struct luks_phdr hdr;
int r = 0, devfd = -1;
ssize_t hdr_size;
ssize_t buffer_size;
char *buffer = NULL;
r = LUKS_read_phdr(&hdr, 1, 0, ctx);
if (r)
return r;
hdr_size = LUKS_device_sectors(hdr.keyBytes) << SECTOR_SHIFT;
buffer_size = size_round_up(hdr_size, crypt_getpagesize());
buffer = crypt_safe_alloc(buffer_size);
if (!buffer || hdr_size < LUKS_ALIGN_KEYSLOTS || hdr_size > buffer_size) {
r = -ENOMEM;
goto out;
}
log_dbg("Storing backup of header (%zu bytes) and keyslot area (%zu bytes).",
sizeof(hdr), hdr_size - LUKS_ALIGN_KEYSLOTS);
log_dbg("Output backup file size: %zu bytes.", buffer_size);
devfd = device_open(device, O_RDONLY);
if(devfd == -1) {
log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device_path(device));
r = -EINVAL;
goto out;
}
if (read_blockwise(devfd, device_block_size(device), buffer, hdr_size) < hdr_size) {
r = -EIO;
goto out;
}
close(devfd);
/* Wipe unused area, so backup cannot contain old signatures */
if (hdr.keyblock[0].keyMaterialOffset * SECTOR_SIZE == LUKS_ALIGN_KEYSLOTS)
memset(buffer + sizeof(hdr), 0, LUKS_ALIGN_KEYSLOTS - sizeof(hdr));
devfd = open(backup_file, O_CREAT|O_EXCL|O_WRONLY, S_IRUSR);
if (devfd == -1) {
if (errno == EEXIST)
log_err(ctx, _("Requested header backup file %s already exists.\n"), backup_file);
else
log_err(ctx, _("Cannot create header backup file %s.\n"), backup_file);
r = -EINVAL;
goto out;
}
if (write(devfd, buffer, buffer_size) < buffer_size) {
log_err(ctx, _("Cannot write header backup file %s.\n"), backup_file);
r = -EIO;
goto out;
}
close(devfd);
r = 0;
out:
if (devfd != -1)
close(devfd);
crypt_memzero(&hdr, sizeof(hdr));
crypt_safe_free(buffer);
return r;
}
/**
* fname_encrypt() -
*
* This function encrypts the input filename, and returns the length of the
* ciphertext. Errors are returned as negative numbers. We trust the caller to
* allocate sufficient memory to oname string.
*/
static int fname_encrypt(struct inode *inode,
const struct qstr *iname, struct fscrypt_str *oname)
{
u32 ciphertext_len;
struct ablkcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_ablkcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[FS_CRYPTO_BLOCK_SIZE];
struct scatterlist src_sg, dst_sg;
int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
char *workbuf, buf[32], *alloc_buf = NULL;
unsigned lim;
lim = inode->i_sb->s_cop->max_namelen(inode);
if (iname->len <= 0 || iname->len > lim)
return -EIO;
ciphertext_len = (iname->len < FS_CRYPTO_BLOCK_SIZE) ?
FS_CRYPTO_BLOCK_SIZE : iname->len;
ciphertext_len = size_round_up(ciphertext_len, padding);
ciphertext_len = (ciphertext_len > lim) ? lim : ciphertext_len;
if (ciphertext_len <= sizeof(buf)) {
workbuf = buf;
} else {
alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
if (!alloc_buf)
return -ENOMEM;
workbuf = alloc_buf;
}
/* Allocate request */
req = ablkcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(KERN_ERR
"%s: crypto_request_alloc() failed\n", __func__);
kfree(alloc_buf);
return -ENOMEM;
}
ablkcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
dir_crypt_complete, &ecr);
/* Copy the input */
memcpy(workbuf, iname->name, iname->len);
if (iname->len < ciphertext_len)
memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
/* Initialize IV */
memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
/* Create encryption request */
sg_init_one(&src_sg, workbuf, ciphertext_len);
sg_init_one(&dst_sg, oname->name, ciphertext_len);
ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
res = crypto_ablkcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
wait_for_completion(&ecr.completion);
res = ecr.res;
}
kfree(alloc_buf);
ablkcipher_request_free(req);
if (res < 0)
printk_ratelimited(KERN_ERR
"%s: Error (error code %d)\n", __func__, res);
oname->len = ciphertext_len;
return res;
}