diff options
Diffstat (limited to 'crypto/polyval-generic.c')
| -rw-r--r-- | crypto/polyval-generic.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/crypto/polyval-generic.c b/crypto/polyval-generic.c index bf2b03b7bfc0..16bfa6925b31 100644 --- a/crypto/polyval-generic.c +++ b/crypto/polyval-generic.c @@ -76,6 +76,46 @@ static void copy_and_reverse(u8 dst[POLYVAL_BLOCK_SIZE], put_unaligned(swab64(b), (u64 *)&dst[0]); } +/* + * Performs multiplication in the POLYVAL field using the GHASH field as a + * subroutine. This function is used as a fallback for hardware accelerated + * implementations when simd registers are unavailable. + * + * Note: This function is not used for polyval-generic, instead we use the 4k + * lookup table implementation for finite field multiplication. + */ +void polyval_mul_non4k(u8 *op1, const u8 *op2) +{ + be128 a, b; + + // Assume one argument is in Montgomery form and one is not. + copy_and_reverse((u8 *)&a, op1); + copy_and_reverse((u8 *)&b, op2); + gf128mul_x_lle(&a, &a); + gf128mul_lle(&a, &b); + copy_and_reverse(op1, (u8 *)&a); +} +EXPORT_SYMBOL_GPL(polyval_mul_non4k); + +/* + * Perform a POLYVAL update using non4k multiplication. This function is used + * as a fallback for hardware accelerated implementations when simd registers + * are unavailable. + * + * Note: This function is not used for polyval-generic, instead we use the 4k + * lookup table implementation of finite field multiplication. + */ +void polyval_update_non4k(const u8 *key, const u8 *in, + size_t nblocks, u8 *accumulator) +{ + while (nblocks--) { + crypto_xor(accumulator, in, POLYVAL_BLOCK_SIZE); + polyval_mul_non4k(accumulator, key); + in += POLYVAL_BLOCK_SIZE; + } +} +EXPORT_SYMBOL_GPL(polyval_update_non4k); + static int polyval_setkey(struct crypto_shash *tfm, const u8 *key, unsigned int keylen) { |