Hi,
I'm implementing a new cipher block within the kernel and I'm stuck into a
problem. My algorithm works pretty well, it can cipher and decipher a block. The
algorithm also works with ECB, CBC, and CTR modes, however when I try to use the
modes such as XTS or LRW I have the following errors which are attached. Did I
need to add more code to make it work with XTS and other modes ?
Cheers,
--
Jonathan "Coldshell" Thieuleux
Mail : [email protected]
IRC : coldshell [Freenode, OFTC]
Shaarli : https://links.stdcall.me/
"If you write interfaces with more than 4 or 5 function arguments, it's
possible that you and I cannot be friends." -- David Miller
-----------------------------Cryptsetup----------------------------
$sudo cryptsetup luksFormat --debug --cipher gost-xts-plain64 ~/test
# cryptsetup 1.6.6 processing "cryptsetup luksFormat --debug --cipher
gost-xts-plain64 /home/coldshell/test"
# Running command luksFormat.
# Locking memory.
# Installing SIGINT/SIGTERM handler.
# Unblocking interruption on signal.
WARNING!
========
This will overwrite data on /home/coldshell/test irrevocably.
Are you sure? (Type uppercase yes): YES
# Allocating crypt device /home/coldshell/test context.
# Trying to open and read device /home/coldshell/test.
# Initialising device-mapper backend library.
# Timeout set to 0 miliseconds.
# Iteration time set to 1000 miliseconds.
# Interactive passphrase entry requested.
Enter passphrase:
Verify passphrase:
# Formatting device /home/coldshell/test as type LUKS1.
# Crypto backend (gcrypt 1.6.3) initialized.
# Detected kernel Linux 3.19.3-3-ARCH x86_64.
# Topology info for /home/coldshell/test not supported, using default offset
1048576 bytes.
# Checking if cipher gost-xts-plain64 is usable.
# Userspace crypto wrapper cannot use gost-xts-plain64 (-2).
# Using dmcrypt to access keyslot area.
# Allocating a free loop device.
# Trying to open and read device /dev/loop0.
# Calculated device size is 8 sectors (RW), offset 0.
# dm version OF [16384] (*1)
# dm versions OF [16384] (*1)
# Detected dm-crypt version 1.13.0, dm-ioctl version 4.29.0.
# Device-mapper backend running with UDEV support enabled.
# DM-UUID is CRYPT-TEMP-temporary-cryptsetup-1570
# Udev cookie 0xd4dffcb (semid 11042818) created
# Udev cookie 0xd4dffcb (semid 11042818) incremented to 1
# Udev cookie 0xd4dffcb (semid 11042818) incremented to 2
# Udev cookie 0xd4dffcb (semid 11042818) assigned to CREATE task(0) with flags
DISABLE_SUBSYSTEM_RULES DISABLE_DISK_RULES DISABLE_OTHER_RULES (0xe)
# dm create temporary-cryptsetup-1570 CRYPT-TEMP-temporary-cryptsetup-1570 OF
[16384] (*1)
# dm reload temporary-cryptsetup-1570 OFRW [16384] (*1)
device-mapper: reload ioctl on failed: Invalid argument
# Udev cookie 0xd4dffcb (semid 11042818) decremented to 1
# Udev cookie 0xd4dffcb (semid 11042818) incremented to 2
# Udev cookie 0xd4dffcb (semid 11042818) assigned to REMOVE task(2) with flags
DISABLE_SUBSYSTEM_RULES DISABLE_DISK_RULES DISABLE_OTHER_RULES (0xe)
# dm remove temporary-cryptsetup-1570 OFRW [16384] (*1)
# temporary-cryptsetup-1570: Stacking NODE_DEL [verify_udev]
# Udev cookie 0xd4dffcb (semid 11042818) decremented to 0
# Udev cookie 0xd4dffcb (semid 11042818) waiting for zero
# Udev cookie 0xd4dffcb (semid 11042818) destroyed
# temporary-cryptsetup-1570: Processing NODE_DEL [verify_udev]
Failed to setup dm-crypt key mapping for device /home/coldshell/test.
Check that kernel supports gost-xts-plain64 cipher (check syslog for more info).
# Releasing crypt device /home/coldshell/test context.
# Releasing device-mapper backend.
# Closed loop /dev/loop0 (/home/coldshell/test).
# Unlocking memory.
Command failed with code 5: Failed to setup dm-crypt key mapping for device
/home/coldshell/test.
Check that kernel supports gost-xts-plain64 cipher (check syslog for more info).
-----------------------------------Dmesg---------------------------------
$dmesg
[159333.709726] device-mapper: table: 254:0: crypt: Error allocating crypto tfm
[159333.709734] device-mapper: ioctl: error adding target to table
-----------------------------------Debug---------------------------------
When I debug, it fails at the function crypto_alloc_ablkcipher(), see below:
file : /drivers/md/dm-crypt.c
1399│ static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1400│ {
1401│ unsigned i;
1402│ int err;
1403│
1404│ cc->tfms = kmalloc(cc->tfms_count * sizeof(struct
crypto_ablkcipher *),
1405│ GFP_KERNEL);
1406│ if (!cc->tfms)
1407│ return -ENOMEM;
1408│
1409│ for (i = 0; i < cc->tfms_count; i++) {
1410│ cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1411├───────────────> if (IS_ERR(cc->tfms[i])) {
1412│ err = PTR_ERR(cc->tfms[i]);
1413│ crypt_free_tfms(cc);
1414│ return err;
1415│ }
1416│ }
1417│
1418│ return 0;
1419│ }
1420│
(gdb) p/x cc->tfms[i]
$1 = 0xffffffffffffffea
Input of the function : crypto_alloc_ablkcipher (alg_name=0xffff880039607cc0
"xts(gost)", type=0, mask=0) at crypto/ablkcipher.c:676
name : xts(gost)
driver : xts(gost-generic)
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : givcipher
async : no
blocksize : 8
min keysize : 64
max keysize : 64
ivsize : 8
geniv : eseqiv
name : xts(gost)
driver : xts(gost-generic)
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : blkcipher
blocksize : 8
min keysize : 64
max keysize : 64
ivsize : 8
geniv : <default>
name : xts(aes)
driver : xts(aes-generic)
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : givcipher
async : no
blocksize : 16
min keysize : 32
max keysize : 64
ivsize : 16
geniv : eseqiv
name : xts(aes)
driver : xts(aes-generic)
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : blkcipher
blocksize : 16
min keysize : 32
max keysize : 64
ivsize : 16
geniv : <default>
name : gost
driver : gost-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : cipher
blocksize : 8
min keysize : 32
max keysize : 32
name : stribog-256
driver : stribog-256-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 32
name : stribog-512
driver : stribog-512-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 64
name : ghash
driver : ghash-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : shash
blocksize : 16
digestsize : 16
name : stdrng
driver : krng
module : kernel
priority : 200
refcnt : 2
selftest : passed
type : rng
seedsize : 0
name : crc32c
driver : crc32c-generic
module : kernel
priority : 100
refcnt : 2
selftest : passed
type : shash
blocksize : 1
digestsize : 4
name : ecb(arc4)
driver : ecb(arc4)-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : blkcipher
blocksize : 1
min keysize : 1
max keysize : 256
ivsize : 0
geniv : <default>
name : arc4
driver : arc4-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : cipher
blocksize : 1
min keysize : 1
max keysize : 256
name : cast5
driver : cast5-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : cipher
blocksize : 8
min keysize : 5
max keysize : 16
name : aes
driver : aes-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : cipher
blocksize : 16
min keysize : 16
max keysize : 32
name : des3_ede
driver : des3_ede-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : cipher
blocksize : 8
min keysize : 24
max keysize : 24
name : des
driver : des-generic
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : cipher
blocksize : 8
min keysize : 8
max keysize : 8
name : tgr128
driver : tgr128-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 16
name : tgr160
driver : tgr160-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 20
name : tgr192
driver : tgr192-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 24
name : wp256
driver : wp256-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 32
name : wp384
driver : wp384-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 48
name : wp512
driver : wp512-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 64
name : sha384
driver : sha384-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 128
digestsize : 48
name : sha512
driver : sha512-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 128
digestsize : 64
name : sha224
driver : sha224-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 28
name : sha256
driver : sha256-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 32
name : sha1
driver : sha1-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 20
name : md5
driver : md5-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 64
digestsize : 16
name : digest_null
driver : digest_null-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : shash
blocksize : 1
digestsize : 0
name : compress_null
driver : compress_null-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : compression
name : ecb(cipher_null)
driver : ecb-cipher_null
module : kernel
priority : 100
refcnt : 1
selftest : passed
type : blkcipher
blocksize : 1
min keysize : 0
max keysize : 0
ivsize : 0
geniv : <default>
name : cipher_null
driver : cipher_null-generic
module : kernel
priority : 0
refcnt : 1
selftest : passed
type : cipher
blocksize : 1
min keysize : 0
max keysize : 0
/*
*
*
* Based on "Applied Cryptography" book
* Dev:
* Me
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/crypto.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <crypto/gost28147-89.h>
int gost_expand_key(struct gost_ctx *CTX, const u8 *key, unsigned int keylen)
{
if(unlikely(keylen != GOST_MAX_KEY_SIZE))
goto gost_expand_keysize_err;
memset(CTX, 0, sizeof(struct gost_ctx));
/* Copy of the cipher key */
memcpy(CTX->key_enc, key, keylen);
if(IS_ERR(CTX->key_dec))
goto gost_expand_copy_err;
/* Copy of the decipher key */
memcpy(CTX->key_dec, key, keylen);
if(IS_ERR(CTX->key_dec))
goto gost_expand_copy_err;
CTX->key_length = keylen;
CTX->sbox = &gost_sboxes[0];
return 0;
gost_expand_keysize_err:
pr_err("An error occurred with the key size, key size is %u,"
"expected size is %u\n", keylen, GOST_MAX_KEY_SIZE);
return -1;
gost_expand_copy_err:
pr_err("An error occurred during the copy of the structure\n");
return -2;
}
inline void split_in_two(const u8 *src, u32 block[2])
{
/* MSB */
block[0] = *(u32 *) src;
/* LSB */
block[1] = *(u32 *) (src + sizeof(u32));
}
inline void merge_in_one(u32 block[2], u8 *dst)
{
dst[0] = block[0] & 0xFF;
dst[1] = block[0] >> 8 & 0xFF;
dst[2] = block[0] >> 16 & 0xFF;
dst[3] = block[0] >> 24 & 0xFF;
dst[4] = block[1] & 0xFF;
dst[5] = block[1] >> 8 & 0xFF;
dst[6] = block[1] >> 16 & 0xFF;
dst[7] = block[1] >> 24 & 0xFF;
}
inline u32 transform(u32 cm1, struct gost_ctx *CTX){
cm1 = (uint32_t) (CTX->sbox->sbox[7][(cm1>>28) & 0xF]<< 28 |
CTX->sbox->sbox[6][cm1>>24 & 0xF] << 24 |
CTX->sbox->sbox[5][cm1>>20 & 0xF] << 20 |
CTX->sbox->sbox[4][cm1>>16 & 0xF] << 16 |
CTX->sbox->sbox[3][cm1>>12 & 0xF] << 12 |
CTX->sbox->sbox[2][cm1>> 8 & 0xF] << 8 |
CTX->sbox->sbox[1][cm1>> 4 & 0xF] << 4 |
CTX->sbox->sbox[0][cm1 & 0xF]);
return (cm1 << 11) | (cm1 >> 21);
}
int gost_setkey(struct crypto_tfm * tfm, const u8 * key,
unsigned int keylen)
{
int ret;
struct gost_ctx *CTX = crypto_tfm_ctx(tfm);
ret = gost_expand_key(CTX, key, keylen);
if(unlikely(ret != 0))
goto gost_expand_err;
return 0;
gost_expand_err:
pr_err("An error occurred during initialization of the key\n");
return -1;
}
EXPORT_SYMBOL(gost_setkey);
void gost_encrypt(struct crypto_tfm * tfm,
u8 * dst,
const u8 * src)
{
u32 in[2], out[2];
register u32 n1, n2; /* see rfc5830 */
struct gost_ctx *CTX = crypto_tfm_ctx(tfm);
split_in_two(src, in);
n1 = in[1]; /* R_{i-1} (lsb)*/
n2 = in[0]; /* L_{i-1} (msb) */
n2 ^= transform(n1+CTX->key_enc[0], CTX);/* n2 = R_{i}; n1 = R_{i-1} = L_{i} */
n1 ^= transform(n2+CTX->key_enc[1], CTX);/* n1 = R{i+1}; n2 = R_{i} = L_{i+1} */
n2 ^= transform(n1+CTX->key_enc[2], CTX);
n1 ^= transform(n2+CTX->key_enc[3], CTX);
n2 ^= transform(n1+CTX->key_enc[4], CTX);
n1 ^= transform(n2+CTX->key_enc[5], CTX);
n2 ^= transform(n1+CTX->key_enc[6], CTX);
n1 ^= transform(n2+CTX->key_enc[7], CTX);
n2 ^= transform(n1+CTX->key_enc[0], CTX);
n1 ^= transform(n2+CTX->key_enc[1], CTX);
n2 ^= transform(n1+CTX->key_enc[2], CTX);
n1 ^= transform(n2+CTX->key_enc[3], CTX);
n2 ^= transform(n1+CTX->key_enc[4], CTX);
n1 ^= transform(n2+CTX->key_enc[5], CTX);
n2 ^= transform(n1+CTX->key_enc[6], CTX);
n1 ^= transform(n2+CTX->key_enc[7], CTX);
n2 ^= transform(n1+CTX->key_enc[0], CTX);
n1 ^= transform(n2+CTX->key_enc[1], CTX);
n2 ^= transform(n1+CTX->key_enc[2], CTX);
n1 ^= transform(n2+CTX->key_enc[3], CTX);
n2 ^= transform(n1+CTX->key_enc[4], CTX);
n1 ^= transform(n2+CTX->key_enc[5], CTX);
n2 ^= transform(n1+CTX->key_enc[6], CTX);
n1 ^= transform(n2+CTX->key_enc[7], CTX);
n2 ^= transform(n1+CTX->key_enc[7], CTX);
n1 ^= transform(n2+CTX->key_enc[6], CTX);
n2 ^= transform(n1+CTX->key_enc[5], CTX);
n1 ^= transform(n2+CTX->key_enc[4], CTX);
n2 ^= transform(n1+CTX->key_enc[3], CTX);
n1 ^= transform(n2+CTX->key_enc[2], CTX);
n2 ^= transform(n1+CTX->key_enc[1], CTX);
n1 ^= transform(n2+CTX->key_enc[0], CTX);
/* In the RFC order - N1, then N2 */
out[0] = n2;
out[1] = n1;
merge_in_one(out, dst);
}
EXPORT_SYMBOL(gost_encrypt);
void gost_decrypt(struct crypto_tfm * tfm,
u8 * dst,
const u8 * src)
{
u32 in[2], out[2];
register u32 n1, n2; /* see rfc5830 */
struct gost_ctx *CTX = crypto_tfm_ctx(tfm);
split_in_two(src, in);
n1 = in[0]; /* R_{i-1} (lsb)*/
n2 = in[1]; /* L_{i-1} (msb) */
n2 ^= transform(n1+CTX->key_dec[0], CTX); /* n2 = R_{i}; n1 = R_{i-1} = L_{i} */
n1 ^= transform(n2+CTX->key_dec[1], CTX); /* n1 = R_{i+1}; n2 = R_{i} = L_{i+1} */
n2 ^= transform(n1+CTX->key_dec[2], CTX);
n1 ^= transform(n2+CTX->key_dec[3], CTX);
n2 ^= transform(n1+CTX->key_dec[4], CTX);
n1 ^= transform(n2+CTX->key_dec[5], CTX);
n2 ^= transform(n1+CTX->key_dec[6], CTX);
n1 ^= transform(n2+CTX->key_dec[7], CTX);
n2 ^= transform(n1+CTX->key_dec[7], CTX);
n1 ^= transform(n2+CTX->key_dec[6], CTX);
n2 ^= transform(n1+CTX->key_dec[5], CTX);
n1 ^= transform(n2+CTX->key_dec[4], CTX);
n2 ^= transform(n1+CTX->key_dec[3], CTX);
n1 ^= transform(n2+CTX->key_dec[2], CTX);
n2 ^= transform(n1+CTX->key_dec[1], CTX);
n1 ^= transform(n2+CTX->key_dec[0], CTX);
n2 ^= transform(n1+CTX->key_dec[7], CTX);
n1 ^= transform(n2+CTX->key_dec[6], CTX);
n2 ^= transform(n1+CTX->key_dec[5], CTX);
n1 ^= transform(n2+CTX->key_dec[4], CTX);
n2 ^= transform(n1+CTX->key_dec[3], CTX);
n1 ^= transform(n2+CTX->key_dec[2], CTX);
n2 ^= transform(n1+CTX->key_dec[1], CTX);
n1 ^= transform(n2+CTX->key_dec[0], CTX);
n2 ^= transform(n1+CTX->key_dec[7], CTX);
n1 ^= transform(n2+CTX->key_dec[6], CTX);
n2 ^= transform(n1+CTX->key_dec[5], CTX);
n1 ^= transform(n2+CTX->key_dec[4], CTX);
n2 ^= transform(n1+CTX->key_dec[3], CTX);
n1 ^= transform(n2+CTX->key_dec[2], CTX);
n2 ^= transform(n1+CTX->key_dec[1], CTX);
n1 ^= transform(n2+CTX->key_dec[0], CTX);
out[0] = n1;
out[1] = n2;
merge_in_one(out, dst);
}
EXPORT_SYMBOL(gost_decrypt);
static struct crypto_alg gost_alg = {
.cra_name = "gost",
.cra_driver_name = "gost-generic",
.cra_priority = 100,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = GOST_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct gost_ctx),
.cra_alignmask = 3,
.cra_module = THIS_MODULE,
.cra_u = {
.cipher = {
.cia_min_keysize = GOST_MIN_KEY_SIZE,
.cia_max_keysize = GOST_MAX_KEY_SIZE,
.cia_setkey = gost_setkey,
.cia_encrypt = gost_encrypt,
.cia_decrypt = gost_decrypt
}
}
};
static int __init gost_init(void)
{
pr_info("Initialization : GOST 28147-89 module\n");
return crypto_register_alg(&gost_alg);
}
static void __exit gost_exit(void)
{
pr_info("Exit : GOST 28147-89 module\n");
crypto_unregister_alg(&gost_alg);
}
module_init(gost_init);
module_exit(gost_exit);
MODULE_DESCRIPTION("GOST 28147-89 cipher algorithm");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CRYPTO("gost28147-89");
MODULE_ALIAS_CRYPTO("gost89");
#ifndef GOST28147_89
#define GOST28147_89
#include <linux/types.h>
#define GOST_BLOCK_SIZE 8
#define GOST_MIN_KEY_SIZE 32
#define GOST_MAX_KEY_SIZE 32
struct gost_s_box {
char *name;
char *oid;
u8 sbox[8][16];
u8 sbox_opti[4][256];
};
struct gost_ctx {
u8 key_enc[GOST_MAX_KEY_SIZE];
u8 key_dec[GOST_MAX_KEY_SIZE];
u8 key_length;
struct gost_s_box *sbox;
};
static struct gost_s_box gost_sboxes[] = {
/*Russian Central Bank*/
{ "test_3411",
"1.2.643.2.2.30.0",
{
{0x4, 0xA, 0x9, 0x2, 0xD, 0x8, 0x0, 0xE, 0x6, 0xB, 0x1, 0xC, 0x7, 0xF, 0x5, 0x3},
{0xE, 0xB, 0x4, 0xC, 0x6, 0xD, 0xF, 0xA, 0x2, 0x3, 0x8, 0x1, 0x0, 0x7, 0x5, 0x9},
{0x5, 0x8, 0x1, 0xD, 0xA, 0x3, 0x4, 0x2, 0xE, 0xF, 0xC, 0x7, 0x6, 0x0, 0x9, 0xB},
{0x7, 0xD, 0xA, 0x1, 0x0, 0x8, 0x9, 0xF, 0xE, 0x4, 0x6, 0xC, 0xB, 0x2, 0x5, 0x3},
{0x6, 0xC, 0x7, 0x1, 0x5, 0xF, 0xD, 0x8, 0x4, 0xA, 0x9, 0xE, 0x0, 0x3, 0xB, 0x2},
{0x4, 0xB, 0xA, 0x0, 0x7, 0x2, 0x1, 0xD, 0x3, 0x6, 0x8, 0x5, 0x9, 0xC, 0xF, 0xE},
{0xD, 0xB, 0x4, 0x1, 0x3, 0xF, 0x5, 0x9, 0x0, 0xA, 0xE, 0x7, 0x6, 0x8, 0x2, 0xC},
{0x1, 0xF, 0xD, 0x0, 0x5, 0x7, 0xA, 0x4, 0x9, 0x2, 0x3, 0xE, 0x6, 0xB, 0x8, 0xC}
},
{
{0},{0},{0},{0}
}
}
};
#endif /* GOST28147_89 */
