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crypto: arm/aes-ce - update IV after partial final CTR block
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Make the arm ctr-aes-ce algorithm update the IV buffer to contain the
next counter after processing a partial final block, rather than leave
it as the last counter.  This makes ctr-aes-ce pass the updated AES-CTR
tests.  This change also makes the code match the arm64 version in
arch/arm64/crypto/aes-modes.S more closely.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Eric Biggers authored and Herbert Xu committed Feb 22, 2019
1 parent fa5fd3a commit 511306b
Showing 1 changed file with 13 additions and 13 deletions.
26 changes: 13 additions & 13 deletions arch/arm/crypto/aes-ce-core.S
Original file line number Diff line number Diff line change
Expand Up @@ -317,25 +317,27 @@ ENTRY(ce_aes_ctr_encrypt)
.Lctrloop:
vmov q0, q6
bl aes_encrypt
subs r4, r4, #1
bmi .Lctrtailblock @ blocks < 0 means tail block
vld1.8 {q3}, [r1]!
veor q3, q0, q3
vst1.8 {q3}, [r0]!

adds r6, r6, #1 @ increment BE ctr
rev ip, r6
vmov s27, ip
bcs .Lctrcarry
teq r4, #0

.Lctrcarrydone:
subs r4, r4, #1
bmi .Lctrtailblock @ blocks < 0 means tail block
vld1.8 {q3}, [r1]!
veor q3, q0, q3
vst1.8 {q3}, [r0]!
bne .Lctrloop

.Lctrout:
vst1.8 {q6}, [r5]
vst1.8 {q6}, [r5] @ return next CTR value
pop {r4-r6, pc}

.Lctrtailblock:
vst1.8 {q0}, [r0, :64] @ return just the key stream
pop {r4-r6, pc}
vst1.8 {q0}, [r0, :64] @ return the key stream
b .Lctrout

.Lctrcarry:
.irp sreg, s26, s25, s24
Expand All @@ -344,11 +346,9 @@ ENTRY(ce_aes_ctr_encrypt)
adds ip, ip, #1
rev ip, ip
vmov \sreg, ip
bcc 0f
bcc .Lctrcarrydone
.endr
0: teq r4, #0
beq .Lctrout
b .Lctrloop
b .Lctrcarrydone
ENDPROC(ce_aes_ctr_encrypt)

/*
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