diff options
| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2017-02-02 11:38:56 +0000 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-02-03 18:16:21 +0800 |
| commit | 1a20b96612656b3ff2d6967c3111bec0e21904a8 (patch) | |
| tree | 02e48e1a60206f1c28ef3ca3950fd04518901669 /arch/arm/crypto/aes-neonbs-core.S | |
| parent | 88a3f582bea9e1da0346ea412950bbbdc3125cc1 (diff) | |
crypto: arm/aes - don't use IV buffer to return final keystream block
The ARM bit sliced AES core code uses the IV buffer to pass the final
keystream block back to the glue code if the input is not a multiple of
the block size, so that the asm code does not have to deal with anything
except 16 byte blocks. This is done under the assumption that the outgoing
IV is meaningless anyway in this case, given that chaining is no longer
possible under these circumstances.
However, as it turns out, the CCM driver does expect the IV to retain
a value that is equal to the original IV except for the counter value,
and even interprets byte zero as a length indicator, which may result
in memory corruption if the IV is overwritten with something else.
So use a separate buffer to return the final keystream block.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm/crypto/aes-neonbs-core.S')
| -rw-r--r-- | arch/arm/crypto/aes-neonbs-core.S | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/arm/crypto/aes-neonbs-core.S b/arch/arm/crypto/aes-neonbs-core.S index 12da247164d1..2b625c6d4712 100644 --- a/arch/arm/crypto/aes-neonbs-core.S +++ b/arch/arm/crypto/aes-neonbs-core.S @@ -779,14 +779,15 @@ ENDPROC(aesbs_cbc_decrypt) /* * aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], - * int rounds, int blocks, u8 ctr[], bool final) + * int rounds, int blocks, u8 ctr[], u8 final[]) */ ENTRY(aesbs_ctr_encrypt) mov ip, sp push {r4-r10, lr} ldm ip, {r5-r7} // load args 4-6 - add r5, r5, r7 // one extra block if final == 1 + teq r7, #0 + addne r5, r5, #1 // one extra block if final != 0 vld1.8 {q0}, [r6] // load counter vrev32.8 q1, q0 @@ -865,19 +866,20 @@ ENTRY(aesbs_ctr_encrypt) veor q2, q2, q14 vst1.8 {q2}, [r0]! teq r4, #0 // skip last block if 'final' - W(bne) 4f + W(bne) 5f 3: veor q5, q5, q15 vst1.8 {q5}, [r0]! - next_ctr q0 +4: next_ctr q0 subs r5, r5, #8 bgt 99b - vmov q5, q0 - -4: vst1.8 {q5}, [r6] + vst1.8 {q0}, [r6] pop {r4-r10, pc} + +5: vst1.8 {q5}, [r4] + b 4b ENDPROC(aesbs_ctr_encrypt) .macro next_tweak, out, in, const, tmp |