| From 009b30ac7444c17fae34c4f435ebce8e8e2b3250 Mon Sep 17 00:00:00 2001 |
| From: Daniel Axtens <dja@axtens.net> |
| Date: Wed, 15 May 2019 20:24:50 +1000 |
| Subject: crypto: vmx - CTR: always increment IV as quadword |
| |
| From: Daniel Axtens <dja@axtens.net> |
| |
| commit 009b30ac7444c17fae34c4f435ebce8e8e2b3250 upstream. |
| |
| The kernel self-tests picked up an issue with CTR mode: |
| alg: skcipher: p8_aes_ctr encryption test failed (wrong result) on test vector 3, cfg="uneven misaligned splits, may sleep" |
| |
| Test vector 3 has an IV of FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFD, so |
| after 3 increments it should wrap around to 0. |
| |
| In the aesp8-ppc code from OpenSSL, there are two paths that |
| increment IVs: the bulk (8 at a time) path, and the individual |
| path which is used when there are fewer than 8 AES blocks to |
| process. |
| |
| In the bulk path, the IV is incremented with vadduqm: "Vector |
| Add Unsigned Quadword Modulo", which does 128-bit addition. |
| |
| In the individual path, however, the IV is incremented with |
| vadduwm: "Vector Add Unsigned Word Modulo", which instead |
| does 4 32-bit additions. Thus the IV would instead become |
| FFFFFFFFFFFFFFFFFFFFFFFF00000000, throwing off the result. |
| |
| Use vadduqm. |
| |
| This was probably a typo originally, what with q and w being |
| adjacent. It is a pretty narrow edge case: I am really |
| impressed by the quality of the kernel self-tests! |
| |
| Fixes: 5c380d623ed3 ("crypto: vmx - Add support for VMS instructions by ASM") |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Daniel Axtens <dja@axtens.net> |
| Acked-by: Nayna Jain <nayna@linux.ibm.com> |
| Tested-by: Nayna Jain <nayna@linux.ibm.com> |
| Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/crypto/vmx/aesp8-ppc.pl | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/crypto/vmx/aesp8-ppc.pl |
| +++ b/drivers/crypto/vmx/aesp8-ppc.pl |
| @@ -1357,7 +1357,7 @@ Loop_ctr32_enc: |
| addi $idx,$idx,16 |
| bdnz Loop_ctr32_enc |
| |
| - vadduwm $ivec,$ivec,$one |
| + vadduqm $ivec,$ivec,$one |
| vmr $dat,$inptail |
| lvx $inptail,0,$inp |
| addi $inp,$inp,16 |
