[PATCH 4.2 085/120] crypto: vmx - Fixing AES-CTR counter bug

Greg Kroah-Hartman
2015-09-19T18:04:26Z

From: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>

commit 1d4aa0b4c1816e8ca92a6aadb0d8f6b43c56c0d0 upstream.

AES-CTR is using a counter 8bytes-8bytes what miss match with
kernel specs.

In the previous code a vadduwm was done to increment counter.
Replacing this for a vadduqm now considering both cases counter
8-8 bytes and full 16bytes.

Signed-off-by: Leonidas S Barbosa <leosilva@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/crypto/vmx/aes_ctr.c | 8 +++++++-
drivers/crypto/vmx/aesp8-ppc.pl | 34 +++++++++++++++++-----------------
2 files changed, 24 insertions(+), 18 deletions(-)

--- a/drivers/crypto/vmx/aes_ctr.c
+++ b/drivers/crypto/vmx/aes_ctr.c
@@ -113,6 +113,7 @@ static int p8_aes_ctr_crypt(struct blkci
struct scatterlist *src, unsigned int nbytes)
{
int ret;
+ u64 inc;
struct blkcipher_walk walk;
struct p8_aes_ctr_ctx *ctx =
crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
@@ -140,7 +141,12 @@ static int p8_aes_ctr_crypt(struct blkci
walk.iv);
pagefault_enable();

- crypto_inc(walk.iv, AES_BLOCK_SIZE);
+ /* We need to update IV mostly for last bytes/round */
+ inc = (nbytes & AES_BLOCK_MASK) / AES_BLOCK_SIZE;
+ if (inc > 0)
+ while (inc--)
+ crypto_inc(walk.iv, AES_BLOCK_SIZE);
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
--- a/drivers/crypto/vmx/aesp8-ppc.pl
+++ b/drivers/crypto/vmx/aesp8-ppc.pl
@@ -1437,28 +1437,28 @@ Load_ctr32_enc_key:
?vperm v31,v31,$out0,$keyperm
lvx v25,$x10,$key_ # pre-load round[2]

- vadduwm $two,$one,$one
+ vadduqm $two,$one,$one
subi $inp,$inp,15 # undo "caller"
$SHL $len,$len,4

- vadduwm $out1,$ivec,$one # counter values ...
- vadduwm $out2,$ivec,$two
+ vadduqm $out1,$ivec,$one # counter values ...
+ vadduqm $out2,$ivec,$two
vxor $out0,$ivec,$rndkey0 # ... xored with rndkey[0]
le?li $idx,8
- vadduwm $out3,$out1,$two
+ vadduqm $out3,$out1,$two
vxor $out1,$out1,$rndkey0
le?lvsl $inpperm,0,$idx
- vadduwm $out4,$out2,$two
+ vadduqm $out4,$out2,$two
vxor $out2,$out2,$rndkey0
le?vspltisb $tmp,0x0f
- vadduwm $out5,$out3,$two
+ vadduqm $out5,$out3,$two
vxor $out3,$out3,$rndkey0
le?vxor $inpperm,$inpperm,$tmp # transform for lvx_u/stvx_u
- vadduwm $out6,$out4,$two
+ vadduqm $out6,$out4,$two
vxor $out4,$out4,$rndkey0
- vadduwm $out7,$out5,$two
+ vadduqm $out7,$out5,$two
vxor $out5,$out5,$rndkey0
- vadduwm $ivec,$out6,$two # next counter value
+ vadduqm $ivec,$out6,$two # next counter value
vxor $out6,$out6,$rndkey0
vxor $out7,$out7,$rndkey0

@@ -1594,27 +1594,27 @@ Loop_ctr32_enc8x_middle:

vcipherlast $in0,$out0,$in0
vcipherlast $in1,$out1,$in1
- vadduwm $out1,$ivec,$one # counter values ...
+ vadduqm $out1,$ivec,$one # counter values ...
vcipherlast $in2,$out2,$in2
- vadduwm $out2,$ivec,$two
+ vadduqm $out2,$ivec,$two
vxor $out0,$ivec,$rndkey0 # ... xored with rndkey[0]
vcipherlast $in3,$out3,$in3
- vadduwm $out3,$out1,$two
+ vadduqm $out3,$out1,$two
vxor $out1,$out1,$rndkey0
vcipherlast $in4,$out4,$in4
- vadduwm $out4,$out2,$two
+ vadduqm $out4,$out2,$two
vxor $out2,$out2,$rndkey0
vcipherlast $in5,$out5,$in5
- vadduwm $out5,$out3,$two
+ vadduqm $out5,$out3,$two
vxor $out3,$out3,$rndkey0
vcipherlast $in6,$out6,$in6
- vadduwm $out6,$out4,$two
+ vadduqm $out6,$out4,$two
vxor $out4,$out4,$rndkey0
vcipherlast $in7,$out7,$in7
- vadduwm $out7,$out5,$two
+ vadduqm $out7,$out5,$two
vxor $out5,$out5,$rndkey0
le?vperm $in0,$in0,$in0,$inpperm
- vadduwm $ivec,$out6,$two # next counter value
+ vadduqm $ivec,$out6,$two # next counter value
vxor $out6,$out6,$rndkey0
le?vperm $in1,$in1,$in1,$inpperm
vxor $out7,$out7,$rndkey0