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armv8crypto: add AES-XTS support

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A straightforward(ish) port from aesni(4). This implementation does not
perform loop unrolling on the input blocks, so this is left as a future
performance improvement.

Submitted by:	Greg V <greg AT unrelenting.technology>
Looks good:	jhb, jmg
Tested by:	mhorne
Differential Revision:	https://reviews.freebsd.org/D21017
This commit is contained in:
Mitchell Horne 2021-01-07 15:30:40 -04:00
parent 1790f5e654
commit 4979620ece
3 changed files with 138 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
sys/crypto/armv8/armv8_crypto.c
View File

@ -114,7 +114,7 @@ armv8_crypto_probe(device_t dev)
break;
}
device_set_desc_copy(dev, "AES-CBC");
device_set_desc_copy(dev, "AES-CBC,AES-XTS");
/* TODO: Check more fields as we support more features */
@ -204,6 +204,17 @@ armv8_crypto_probesession(device_t dev,
return (EINVAL);
}
break;
case CRYPTO_AES_XTS:
if (csp->csp_ivlen != AES_XTS_IV_LEN)
return (EINVAL);
switch (csp->csp_cipher_klen * 8) {
case 256:
case 512:
break;
default:
return (EINVAL);
}
break;
default:
return (EINVAL);
}
@ -211,16 +222,19 @@ armv8_crypto_probesession(device_t dev,
default:
return (EINVAL);
}
return (CRYPTODEV_PROBE_ACCEL_SOFTWARE);
return (CRYPTODEV_PROBE_ACCEL_SOFTWARE);
}
static void
armv8_crypto_cipher_setup(struct armv8_crypto_session *ses,
const struct crypto_session_params *csp)
const struct crypto_session_params *csp, const uint8_t *key, int keylen)
{
int i;
switch (csp->csp_cipher_klen * 8) {
if (csp->csp_cipher_alg == CRYPTO_AES_XTS)
keylen /= 2;
switch (keylen * 8) {
case 128:
ses->rounds = AES128_ROUNDS;
break;
@ -231,16 +245,19 @@ armv8_crypto_cipher_setup(struct armv8_crypto_session *ses,
ses->rounds = AES256_ROUNDS;
break;
default:
panic("invalid CBC key length");
panic("invalid AES key length");
}
rijndaelKeySetupEnc(ses->enc_schedule, csp->csp_cipher_key,
csp->csp_cipher_klen * 8);
rijndaelKeySetupDec(ses->dec_schedule, csp->csp_cipher_key,
csp->csp_cipher_klen * 8);
rijndaelKeySetupEnc(ses->enc_schedule, key, keylen * 8);
rijndaelKeySetupDec(ses->dec_schedule, key, keylen * 8);
if (csp->csp_cipher_alg == CRYPTO_AES_XTS)
rijndaelKeySetupEnc(ses->xts_schedule, key + keylen, keylen * 8);
for (i = 0; i < nitems(ses->enc_schedule); i++) {
ses->enc_schedule[i] = bswap32(ses->enc_schedule[i]);
ses->dec_schedule[i] = bswap32(ses->dec_schedule[i]);
if (csp->csp_cipher_alg == CRYPTO_AES_XTS)
ses->xts_schedule[i] = bswap32(ses->xts_schedule[i]);
}
}
@ -259,7 +276,8 @@ armv8_crypto_newsession(device_t dev, crypto_session_t cses,
}
ses = crypto_get_driver_session(cses);
armv8_crypto_cipher_setup(ses, csp);
armv8_crypto_cipher_setup(ses, csp, csp->csp_cipher_key,
csp->csp_cipher_klen);
rw_wunlock(&sc->lock);
return (0);
}
@ -333,7 +351,8 @@ armv8_crypto_cipher_process(struct armv8_crypto_session *ses,
}
if (crp->crp_cipher_key != NULL) {
panic("armv8: new cipher key");
armv8_crypto_cipher_setup(ses, csp, crp->crp_cipher_key,
csp->csp_cipher_klen);
}
crypto_read_iv(crp, iv);
@ -348,6 +367,16 @@ armv8_crypto_cipher_process(struct armv8_crypto_session *ses,
armv8_aes_decrypt_cbc(ses->rounds, ses->dec_schedule,
crp->crp_payload_length, buf, iv);
break;
case CRYPTO_AES_XTS:
if (encflag)
armv8_aes_encrypt_xts(ses->rounds, ses->enc_schedule,
ses->xts_schedule, crp->crp_payload_length, buf,
buf, iv);
else
armv8_aes_decrypt_xts(ses->rounds, ses->dec_schedule,
ses->xts_schedule, crp->crp_payload_length, buf,
buf, iv);
break;
}
if (allocated)

6
sys/crypto/armv8/armv8_crypto.h
View File

@ -40,6 +40,7 @@
struct armv8_crypto_session {
uint32_t enc_schedule[AES_SCHED_LEN/4];
uint32_t dec_schedule[AES_SCHED_LEN/4];
uint32_t xts_schedule[AES_SCHED_LEN/4];
int algo;
int rounds;
};
@ -49,4 +50,9 @@ void armv8_aes_encrypt_cbc(int, const void *, size_t, const uint8_t *,
void armv8_aes_decrypt_cbc(int, const void *, size_t, uint8_t *,
const uint8_t[static AES_BLOCK_LEN]);
void armv8_aes_encrypt_xts(int, const void *, const void *, size_t,
const uint8_t *, uint8_t *, const uint8_t[AES_BLOCK_LEN]);
void armv8_aes_decrypt_xts(int, const void *, const void *, size_t,
const uint8_t *, uint8_t *, const uint8_t[AES_BLOCK_LEN]);
#endif /* _ARMV8_CRYPTO_H_ */

92
sys/crypto/armv8/armv8_crypto_wrap.c
View File

@ -126,3 +126,95 @@ armv8_aes_decrypt_cbc(int rounds, const void *key_schedule, size_t len,
buf += AES_BLOCK_LEN;
}
}
#define AES_XTS_BLOCKSIZE 16
#define AES_XTS_IVSIZE 8
#define AES_XTS_ALPHA 0x87 /* GF(2^128) generator polynomial */
static inline int32x4_t
xts_crank_lfsr(int32x4_t inp)
{
const int32x4_t alphamask = {AES_XTS_ALPHA, 1, 1, 1};
int32x4_t xtweak, ret;
/* set up xor mask */
xtweak = vextq_s32(inp, inp, 3);
xtweak = vshrq_n_s32(xtweak, 31);
xtweak &= alphamask;
/* next term */
ret = vshlq_n_s32(inp, 1);
ret ^= xtweak;
return ret;
}
static void
armv8_aes_crypt_xts_block(int rounds, const uint8x16_t *key_schedule,
uint8x16_t *tweak, const uint8_t *from, uint8_t *to, int do_encrypt)
{
uint8x16_t block;
block = vld1q_u8(from) ^ *tweak;
if (do_encrypt)
block = armv8_aes_enc(rounds - 1, key_schedule, block);
else
block = armv8_aes_dec(rounds - 1, key_schedule, block);
vst1q_u8(to, block ^ *tweak);
*tweak = vreinterpretq_u8_s32(xts_crank_lfsr(vreinterpretq_s32_u8(*tweak)));
}
static void
armv8_aes_crypt_xts(int rounds, const uint8x16_t *data_schedule,
const uint8x16_t *tweak_schedule, size_t len, const uint8_t *from,
uint8_t *to, const uint8_t iv[static AES_BLOCK_LEN], int do_encrypt)
{
uint8x16_t tweakreg;
uint8_t tweak[AES_XTS_BLOCKSIZE] __aligned(16);
size_t i, cnt;
/*
* Prepare tweak as E_k2(IV). IV is specified as LE representation
* of a 64-bit block number which we allow to be passed in directly.
*/
#if BYTE_ORDER == LITTLE_ENDIAN
bcopy(iv, tweak, AES_XTS_IVSIZE);
/* Last 64 bits of IV are always zero. */
bzero(tweak + AES_XTS_IVSIZE, AES_XTS_IVSIZE);
#else
#error Only LITTLE_ENDIAN architectures are supported.
#endif
tweakreg = vld1q_u8(tweak);
tweakreg = armv8_aes_enc(rounds - 1, tweak_schedule, tweakreg);
cnt = len / AES_XTS_BLOCKSIZE;
for (i = 0; i < cnt; i++) {
armv8_aes_crypt_xts_block(rounds, data_schedule, &tweakreg,
from, to, do_encrypt);
from += AES_XTS_BLOCKSIZE;
to += AES_XTS_BLOCKSIZE;
}
}
void
armv8_aes_encrypt_xts(int rounds, const void *data_schedule,
const void *tweak_schedule, size_t len, const uint8_t *from, uint8_t *to,
const uint8_t iv[static AES_BLOCK_LEN])
{
armv8_aes_crypt_xts(rounds, data_schedule, tweak_schedule, len, from, to,
iv, 1);
}
void
armv8_aes_decrypt_xts(int rounds, const void *data_schedule,
const void *tweak_schedule, size_t len, const uint8_t *from, uint8_t *to,
const uint8_t iv[static AES_BLOCK_LEN])
{
armv8_aes_crypt_xts(rounds, data_schedule, tweak_schedule, len, from, to,
iv, 0);
}