linux/crypto/cast6_generic.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/* Kernel cryptographic api.
* cast6.c - Cast6 cipher algorithm [rfc2612].
*
* CAST-256 (*cast6*) is a DES like Substitution-Permutation Network (SPN)
* cryptosystem built upon the CAST-128 (*cast5*) [rfc2144] encryption
* algorithm.
*
* Copyright (C) 2003 Kartikey Mahendra Bhatt <kartik_me@hotmail.com>.
*/
#include <asm/unaligned.h>
#include <crypto/algapi.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <crypto/cast6.h>
#define s1 cast_s1
#define s2 cast_s2
#define s3 cast_s3
#define s4 cast_s4
#define F1(D, r, m) ((I = ((m) + (D))), (I = rol32(I, (r))), \
(((s1[I >> 24] ^ s2[(I>>16)&0xff]) - s3[(I>>8)&0xff]) + s4[I&0xff]))
#define F2(D, r, m) ((I = ((m) ^ (D))), (I = rol32(I, (r))), \
(((s1[I >> 24] - s2[(I>>16)&0xff]) + s3[(I>>8)&0xff]) ^ s4[I&0xff]))
#define F3(D, r, m) ((I = ((m) - (D))), (I = rol32(I, (r))), \
(((s1[I >> 24] + s2[(I>>16)&0xff]) ^ s3[(I>>8)&0xff]) - s4[I&0xff]))
static const u32 Tm[24][8] = {
{ 0x5a827999, 0xc95c653a, 0x383650db, 0xa7103c7c, 0x15ea281d,
0x84c413be, 0xf39dff5f, 0x6277eb00 } ,
{ 0xd151d6a1, 0x402bc242, 0xaf05ade3, 0x1ddf9984, 0x8cb98525,
0xfb9370c6, 0x6a6d5c67, 0xd9474808 } ,
{ 0x482133a9, 0xb6fb1f4a, 0x25d50aeb, 0x94aef68c, 0x0388e22d,
0x7262cdce, 0xe13cb96f, 0x5016a510 } ,
{ 0xbef090b1, 0x2dca7c52, 0x9ca467f3, 0x0b7e5394, 0x7a583f35,
0xe9322ad6, 0x580c1677, 0xc6e60218 } ,
{ 0x35bfedb9, 0xa499d95a, 0x1373c4fb, 0x824db09c, 0xf1279c3d,
0x600187de, 0xcedb737f, 0x3db55f20 } ,
{ 0xac8f4ac1, 0x1b693662, 0x8a432203, 0xf91d0da4, 0x67f6f945,
0xd6d0e4e6, 0x45aad087, 0xb484bc28 } ,
{ 0x235ea7c9, 0x9238936a, 0x01127f0b, 0x6fec6aac, 0xdec6564d,
0x4da041ee, 0xbc7a2d8f, 0x2b541930 } ,
{ 0x9a2e04d1, 0x0907f072, 0x77e1dc13, 0xe6bbc7b4, 0x5595b355,
0xc46f9ef6, 0x33498a97, 0xa2237638 } ,
{ 0x10fd61d9, 0x7fd74d7a, 0xeeb1391b, 0x5d8b24bc, 0xcc65105d,
0x3b3efbfe, 0xaa18e79f, 0x18f2d340 } ,
{ 0x87ccbee1, 0xf6a6aa82, 0x65809623, 0xd45a81c4, 0x43346d65,
0xb20e5906, 0x20e844a7, 0x8fc23048 } ,
{ 0xfe9c1be9, 0x6d76078a, 0xdc4ff32b, 0x4b29decc, 0xba03ca6d,
0x28ddb60e, 0x97b7a1af, 0x06918d50 } ,
{ 0x756b78f1, 0xe4456492, 0x531f5033, 0xc1f93bd4, 0x30d32775,
0x9fad1316, 0x0e86feb7, 0x7d60ea58 } ,
{ 0xec3ad5f9, 0x5b14c19a, 0xc9eead3b, 0x38c898dc, 0xa7a2847d,
0x167c701e, 0x85565bbf, 0xf4304760 } ,
{ 0x630a3301, 0xd1e41ea2, 0x40be0a43, 0xaf97f5e4, 0x1e71e185,
0x8d4bcd26, 0xfc25b8c7, 0x6affa468 } ,
{ 0xd9d99009, 0x48b37baa, 0xb78d674b, 0x266752ec, 0x95413e8d,
0x041b2a2e, 0x72f515cf, 0xe1cf0170 } ,
{ 0x50a8ed11, 0xbf82d8b2, 0x2e5cc453, 0x9d36aff4, 0x0c109b95,
0x7aea8736, 0xe9c472d7, 0x589e5e78 } ,
{ 0xc7784a19, 0x365235ba, 0xa52c215b, 0x14060cfc, 0x82dff89d,
0xf1b9e43e, 0x6093cfdf, 0xcf6dbb80 } ,
{ 0x3e47a721, 0xad2192c2, 0x1bfb7e63, 0x8ad56a04, 0xf9af55a5,
0x68894146, 0xd7632ce7, 0x463d1888 } ,
{ 0xb5170429, 0x23f0efca, 0x92cadb6b, 0x01a4c70c, 0x707eb2ad,
0xdf589e4e, 0x4e3289ef, 0xbd0c7590 } ,
{ 0x2be66131, 0x9ac04cd2, 0x099a3873, 0x78742414, 0xe74e0fb5,
0x5627fb56, 0xc501e6f7, 0x33dbd298 } ,
{ 0xa2b5be39, 0x118fa9da, 0x8069957b, 0xef43811c, 0x5e1d6cbd,
0xccf7585e, 0x3bd143ff, 0xaaab2fa0 } ,
{ 0x19851b41, 0x885f06e2, 0xf738f283, 0x6612de24, 0xd4ecc9c5,
0x43c6b566, 0xb2a0a107, 0x217a8ca8 } ,
{ 0x90547849, 0xff2e63ea, 0x6e084f8b, 0xdce23b2c, 0x4bbc26cd,
0xba96126e, 0x296ffe0f, 0x9849e9b0 } ,
{ 0x0723d551, 0x75fdc0f2, 0xe4d7ac93, 0x53b19834, 0xc28b83d5,
0x31656f76, 0xa03f5b17, 0x0f1946b8 }
};
static const u8 Tr[4][8] = {
{ 0x13, 0x04, 0x15, 0x06, 0x17, 0x08, 0x19, 0x0a } ,
{ 0x1b, 0x0c, 0x1d, 0x0e, 0x1f, 0x10, 0x01, 0x12 } ,
{ 0x03, 0x14, 0x05, 0x16, 0x07, 0x18, 0x09, 0x1a } ,
{ 0x0b, 0x1c, 0x0d, 0x1e, 0x0f, 0x00, 0x11, 0x02 }
};
/* forward octave */
static inline void W(u32 *key, unsigned int i)
{
u32 I;
key[6] ^= F1(key[7], Tr[i % 4][0], Tm[i][0]);
key[5] ^= F2(key[6], Tr[i % 4][1], Tm[i][1]);
key[4] ^= F3(key[5], Tr[i % 4][2], Tm[i][2]);
key[3] ^= F1(key[4], Tr[i % 4][3], Tm[i][3]);
key[2] ^= F2(key[3], Tr[i % 4][4], Tm[i][4]);
key[1] ^= F3(key[2], Tr[i % 4][5], Tm[i][5]);
key[0] ^= F1(key[1], Tr[i % 4][6], Tm[i][6]);
key[7] ^= F2(key[0], Tr[i % 4][7], Tm[i][7]);
}
crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to make the ->setkey() functions provide more information about errors. However, no one actually checks for this flag, which makes it pointless. Also, many algorithms fail to set this flag when given a bad length key. Reviewing just the generic implementations, this is the case for aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309, rfc7539, rfc7539esp, salsa20, seqiv, and xcbc. But there are probably many more in arch/*/crypto/ and drivers/crypto/. Some algorithms can even set this flag when the key is the correct length. For example, authenc and authencesn set it when the key payload is malformed in any way (not just a bad length), the atmel-sha and ccree drivers can set it if a memory allocation fails, and the chelsio driver sets it for bad auth tag lengths, not just bad key lengths. So even if someone actually wanted to start checking this flag (which seems unlikely, since it's been unused for a long time), there would be a lot of work needed to get it working correctly. But it would probably be much better to go back to the drawing board and just define different return values, like -EINVAL if the key is invalid for the algorithm vs. -EKEYREJECTED if the key was rejected by a policy like "no weak keys". That would be much simpler, less error-prone, and easier to test. So just remove this flag. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Horia Geantă <horia.geanta@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-31 03:19:36 +00:00
int __cast6_setkey(struct cast6_ctx *c, const u8 *in_key, unsigned int key_len)
{
int i;
u32 key[8];
__be32 p_key[8]; /* padded key */
crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to make the ->setkey() functions provide more information about errors. However, no one actually checks for this flag, which makes it pointless. Also, many algorithms fail to set this flag when given a bad length key. Reviewing just the generic implementations, this is the case for aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309, rfc7539, rfc7539esp, salsa20, seqiv, and xcbc. But there are probably many more in arch/*/crypto/ and drivers/crypto/. Some algorithms can even set this flag when the key is the correct length. For example, authenc and authencesn set it when the key payload is malformed in any way (not just a bad length), the atmel-sha and ccree drivers can set it if a memory allocation fails, and the chelsio driver sets it for bad auth tag lengths, not just bad key lengths. So even if someone actually wanted to start checking this flag (which seems unlikely, since it's been unused for a long time), there would be a lot of work needed to get it working correctly. But it would probably be much better to go back to the drawing board and just define different return values, like -EINVAL if the key is invalid for the algorithm vs. -EKEYREJECTED if the key was rejected by a policy like "no weak keys". That would be much simpler, less error-prone, and easier to test. So just remove this flag. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Horia Geantă <horia.geanta@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-31 03:19:36 +00:00
if (key_len % 4 != 0)
return -EINVAL;
memset(p_key, 0, 32);
memcpy(p_key, in_key, key_len);
key[0] = be32_to_cpu(p_key[0]); /* A */
key[1] = be32_to_cpu(p_key[1]); /* B */
key[2] = be32_to_cpu(p_key[2]); /* C */
key[3] = be32_to_cpu(p_key[3]); /* D */
key[4] = be32_to_cpu(p_key[4]); /* E */
key[5] = be32_to_cpu(p_key[5]); /* F */
key[6] = be32_to_cpu(p_key[6]); /* G */
key[7] = be32_to_cpu(p_key[7]); /* H */
for (i = 0; i < 12; i++) {
W(key, 2 * i);
W(key, 2 * i + 1);
c->Kr[i][0] = key[0] & 0x1f;
c->Kr[i][1] = key[2] & 0x1f;
c->Kr[i][2] = key[4] & 0x1f;
c->Kr[i][3] = key[6] & 0x1f;
c->Km[i][0] = key[7];
c->Km[i][1] = key[5];
c->Km[i][2] = key[3];
c->Km[i][3] = key[1];
}
return 0;
}
EXPORT_SYMBOL_GPL(__cast6_setkey);
int cast6_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to make the ->setkey() functions provide more information about errors. However, no one actually checks for this flag, which makes it pointless. Also, many algorithms fail to set this flag when given a bad length key. Reviewing just the generic implementations, this is the case for aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309, rfc7539, rfc7539esp, salsa20, seqiv, and xcbc. But there are probably many more in arch/*/crypto/ and drivers/crypto/. Some algorithms can even set this flag when the key is the correct length. For example, authenc and authencesn set it when the key payload is malformed in any way (not just a bad length), the atmel-sha and ccree drivers can set it if a memory allocation fails, and the chelsio driver sets it for bad auth tag lengths, not just bad key lengths. So even if someone actually wanted to start checking this flag (which seems unlikely, since it's been unused for a long time), there would be a lot of work needed to get it working correctly. But it would probably be much better to go back to the drawing board and just define different return values, like -EINVAL if the key is invalid for the algorithm vs. -EKEYREJECTED if the key was rejected by a policy like "no weak keys". That would be much simpler, less error-prone, and easier to test. So just remove this flag. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Horia Geantă <horia.geanta@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-31 03:19:36 +00:00
return __cast6_setkey(crypto_tfm_ctx(tfm), key, keylen);
}
EXPORT_SYMBOL_GPL(cast6_setkey);
/*forward quad round*/
static inline void Q(u32 *block, const u8 *Kr, const u32 *Km)
{
u32 I;
block[2] ^= F1(block[3], Kr[0], Km[0]);
block[1] ^= F2(block[2], Kr[1], Km[1]);
block[0] ^= F3(block[1], Kr[2], Km[2]);
block[3] ^= F1(block[0], Kr[3], Km[3]);
}
/*reverse quad round*/
static inline void QBAR(u32 *block, const u8 *Kr, const u32 *Km)
{
u32 I;
block[3] ^= F1(block[0], Kr[3], Km[3]);
block[0] ^= F3(block[1], Kr[2], Km[2]);
block[1] ^= F2(block[2], Kr[1], Km[1]);
block[2] ^= F1(block[3], Kr[0], Km[0]);
}
void __cast6_encrypt(const void *ctx, u8 *outbuf, const u8 *inbuf)
{
const struct cast6_ctx *c = ctx;
u32 block[4];
const u32 *Km;
const u8 *Kr;
block[0] = get_unaligned_be32(inbuf);
block[1] = get_unaligned_be32(inbuf + 4);
block[2] = get_unaligned_be32(inbuf + 8);
block[3] = get_unaligned_be32(inbuf + 12);
Km = c->Km[0]; Kr = c->Kr[0]; Q(block, Kr, Km);
Km = c->Km[1]; Kr = c->Kr[1]; Q(block, Kr, Km);
Km = c->Km[2]; Kr = c->Kr[2]; Q(block, Kr, Km);
Km = c->Km[3]; Kr = c->Kr[3]; Q(block, Kr, Km);
Km = c->Km[4]; Kr = c->Kr[4]; Q(block, Kr, Km);
Km = c->Km[5]; Kr = c->Kr[5]; Q(block, Kr, Km);
Km = c->Km[6]; Kr = c->Kr[6]; QBAR(block, Kr, Km);
Km = c->Km[7]; Kr = c->Kr[7]; QBAR(block, Kr, Km);
Km = c->Km[8]; Kr = c->Kr[8]; QBAR(block, Kr, Km);
Km = c->Km[9]; Kr = c->Kr[9]; QBAR(block, Kr, Km);
Km = c->Km[10]; Kr = c->Kr[10]; QBAR(block, Kr, Km);
Km = c->Km[11]; Kr = c->Kr[11]; QBAR(block, Kr, Km);
put_unaligned_be32(block[0], outbuf);
put_unaligned_be32(block[1], outbuf + 4);
put_unaligned_be32(block[2], outbuf + 8);
put_unaligned_be32(block[3], outbuf + 12);
}
EXPORT_SYMBOL_GPL(__cast6_encrypt);
static void cast6_encrypt(struct crypto_tfm *tfm, u8 *outbuf, const u8 *inbuf)
{
__cast6_encrypt(crypto_tfm_ctx(tfm), outbuf, inbuf);
}
void __cast6_decrypt(const void *ctx, u8 *outbuf, const u8 *inbuf)
{
const struct cast6_ctx *c = ctx;
u32 block[4];
const u32 *Km;
const u8 *Kr;
block[0] = get_unaligned_be32(inbuf);
block[1] = get_unaligned_be32(inbuf + 4);
block[2] = get_unaligned_be32(inbuf + 8);
block[3] = get_unaligned_be32(inbuf + 12);
Km = c->Km[11]; Kr = c->Kr[11]; Q(block, Kr, Km);
Km = c->Km[10]; Kr = c->Kr[10]; Q(block, Kr, Km);
Km = c->Km[9]; Kr = c->Kr[9]; Q(block, Kr, Km);
Km = c->Km[8]; Kr = c->Kr[8]; Q(block, Kr, Km);
Km = c->Km[7]; Kr = c->Kr[7]; Q(block, Kr, Km);
Km = c->Km[6]; Kr = c->Kr[6]; Q(block, Kr, Km);
Km = c->Km[5]; Kr = c->Kr[5]; QBAR(block, Kr, Km);
Km = c->Km[4]; Kr = c->Kr[4]; QBAR(block, Kr, Km);
Km = c->Km[3]; Kr = c->Kr[3]; QBAR(block, Kr, Km);
Km = c->Km[2]; Kr = c->Kr[2]; QBAR(block, Kr, Km);
Km = c->Km[1]; Kr = c->Kr[1]; QBAR(block, Kr, Km);
Km = c->Km[0]; Kr = c->Kr[0]; QBAR(block, Kr, Km);
put_unaligned_be32(block[0], outbuf);
put_unaligned_be32(block[1], outbuf + 4);
put_unaligned_be32(block[2], outbuf + 8);
put_unaligned_be32(block[3], outbuf + 12);
}
EXPORT_SYMBOL_GPL(__cast6_decrypt);
static void cast6_decrypt(struct crypto_tfm *tfm, u8 *outbuf, const u8 *inbuf)
{
__cast6_decrypt(crypto_tfm_ctx(tfm), outbuf, inbuf);
}
static struct crypto_alg alg = {
.cra_name = "cast6",
.cra_driver_name = "cast6-generic",
.cra_priority = 100,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = CAST6_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct cast6_ctx),
.cra_module = THIS_MODULE,
.cra_u = {
.cipher = {
.cia_min_keysize = CAST6_MIN_KEY_SIZE,
.cia_max_keysize = CAST6_MAX_KEY_SIZE,
.cia_setkey = cast6_setkey,
.cia_encrypt = cast6_encrypt,
.cia_decrypt = cast6_decrypt}
}
};
static int __init cast6_mod_init(void)
{
return crypto_register_alg(&alg);
}
static void __exit cast6_mod_fini(void)
{
crypto_unregister_alg(&alg);
}
subsys_initcall(cast6_mod_init);
module_exit(cast6_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cast6 Cipher Algorithm");
MODULE_ALIAS_CRYPTO("cast6");
MODULE_ALIAS_CRYPTO("cast6-generic");