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