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| author |   Ard Biesheuvel <ardb@kernel.org> | 2020-11-10 10:10:42 +0100 |
|---|---|---|
| committer |   Herbert Xu <herbert@gondor.apana.org.au> | 2020-11-20 14:45:32 +1100 |
| commit | 3ad99c22cebee84034bc53e42f5115dbc97490e8 (patch) | |
| tree | ae5d8b21d02aab542d2040e79e69b9cb7ecf0301 /arch/arm64/crypto/ghash-ce-core.S | |
| parent | crypto: hisilicon/sec2 - Fix aead authentication setting key error (diff) | |
| download | linux-dev-3ad99c22cebee84034bc53e42f5115dbc97490e8.tar.xz linux-dev-3ad99c22cebee84034bc53e42f5115dbc97490e8.zip | |
crypto: arm64/gcm - move authentication tag check to SIMD domain
Instead of copying the calculated authentication tag to memory and
calling crypto_memneq() to verify it, use vector bytewise compare and
min across vector instructions to decide whether the tag is valid. This
is more efficient, and given that the tag is only transiently held in a
NEON register, it is also safer, given that calculated tags for failed
decryptions should be withheld.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm64/crypto/ghash-ce-core.S')
| -rw-r--r-- | arch/arm64/crypto/ghash-ce-core.S | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/crypto/ghash-ce-core.S b/arch/arm64/crypto/ghash-ce-core.S index 6b958dcdf136..7868330dd54e 100644 --- a/arch/arm64/crypto/ghash-ce-core.S +++ b/arch/arm64/crypto/ghash-ce-core.S @@ -544,7 +544,22 @@ CPU_LE( rev w8, w8 ) ext XL.16b, XL.16b, XL.16b, #8 rev64 XL.16b, XL.16b eor XL.16b, XL.16b, KS0.16b + + .if \enc == 1 st1 {XL.16b}, [x10] // store tag + .else + ldp x11, x12, [sp, #40] // load tag pointer and authsize + adr_l x17, .Lpermute_table + ld1 {KS0.16b}, [x11] // load supplied tag + add x17, x17, x12 + ld1 {KS1.16b}, [x17] // load permute vector + + cmeq XL.16b, XL.16b, KS0.16b // compare tags + mvn XL.16b, XL.16b // -1 for fail, 0 for pass + tbl XL.16b, {XL.16b}, KS1.16b // keep authsize bytes only + sminv b0, XL.16b // signed minimum across XL + smov w0, v0.b[0] // return b0 + .endif 4: ldp x29, x30, [sp], #32 ret |