linux/arch/arm/crypto/aes-ce-core.S
Ard Biesheuvel 6499e8cfaa crypto: arm/aes - streamline AES-192 code path
This trims off a couple of instructions of the total size of the
core AES transform by reordering the final branch in the AES-192
code path with the rounds that are performed regardless of whether
the branch is taken or not. Other than the slight size reduction,
this has no performance benefit.

Fix up a comment regarding the prototype of this function while
we're at it.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-11 15:08:01 +08:00

518 lines
11 KiB
ArmAsm

/*
* aes-ce-core.S - AES in CBC/CTR/XTS mode using ARMv8 Crypto Extensions
*
* Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
.text
.fpu crypto-neon-fp-armv8
.align 3
.macro enc_round, state, key
aese.8 \state, \key
aesmc.8 \state, \state
.endm
.macro dec_round, state, key
aesd.8 \state, \key
aesimc.8 \state, \state
.endm
.macro enc_dround, key1, key2
enc_round q0, \key1
enc_round q0, \key2
.endm
.macro dec_dround, key1, key2
dec_round q0, \key1
dec_round q0, \key2
.endm
.macro enc_fround, key1, key2, key3
enc_round q0, \key1
aese.8 q0, \key2
veor q0, q0, \key3
.endm
.macro dec_fround, key1, key2, key3
dec_round q0, \key1
aesd.8 q0, \key2
veor q0, q0, \key3
.endm
.macro enc_dround_3x, key1, key2
enc_round q0, \key1
enc_round q1, \key1
enc_round q2, \key1
enc_round q0, \key2
enc_round q1, \key2
enc_round q2, \key2
.endm
.macro dec_dround_3x, key1, key2
dec_round q0, \key1
dec_round q1, \key1
dec_round q2, \key1
dec_round q0, \key2
dec_round q1, \key2
dec_round q2, \key2
.endm
.macro enc_fround_3x, key1, key2, key3
enc_round q0, \key1
enc_round q1, \key1
enc_round q2, \key1
aese.8 q0, \key2
aese.8 q1, \key2
aese.8 q2, \key2
veor q0, q0, \key3
veor q1, q1, \key3
veor q2, q2, \key3
.endm
.macro dec_fround_3x, key1, key2, key3
dec_round q0, \key1
dec_round q1, \key1
dec_round q2, \key1
aesd.8 q0, \key2
aesd.8 q1, \key2
aesd.8 q2, \key2
veor q0, q0, \key3
veor q1, q1, \key3
veor q2, q2, \key3
.endm
.macro do_block, dround, fround
cmp r3, #12 @ which key size?
vld1.8 {q10-q11}, [ip]!
\dround q8, q9
vld1.8 {q12-q13}, [ip]!
\dround q10, q11
vld1.8 {q10-q11}, [ip]!
\dround q12, q13
vld1.8 {q12-q13}, [ip]!
\dround q10, q11
blo 0f @ AES-128: 10 rounds
vld1.8 {q10-q11}, [ip]!
\dround q12, q13
beq 1f @ AES-192: 12 rounds
vld1.8 {q12-q13}, [ip]
\dround q10, q11
0: \fround q12, q13, q14
bx lr
1: \fround q10, q11, q14
bx lr
.endm
/*
* Internal, non-AAPCS compliant functions that implement the core AES
* transforms. These should preserve all registers except q0 - q2 and ip
* Arguments:
* q0 : first in/output block
* q1 : second in/output block (_3x version only)
* q2 : third in/output block (_3x version only)
* q8 : first round key
* q9 : secound round key
* q14 : final round key
* r2 : address of round key array
* r3 : number of rounds
*/
.align 6
aes_encrypt:
add ip, r2, #32 @ 3rd round key
.Laes_encrypt_tweak:
do_block enc_dround, enc_fround
ENDPROC(aes_encrypt)
.align 6
aes_decrypt:
add ip, r2, #32 @ 3rd round key
do_block dec_dround, dec_fround
ENDPROC(aes_decrypt)
.align 6
aes_encrypt_3x:
add ip, r2, #32 @ 3rd round key
do_block enc_dround_3x, enc_fround_3x
ENDPROC(aes_encrypt_3x)
.align 6
aes_decrypt_3x:
add ip, r2, #32 @ 3rd round key
do_block dec_dround_3x, dec_fround_3x
ENDPROC(aes_decrypt_3x)
.macro prepare_key, rk, rounds
add ip, \rk, \rounds, lsl #4
vld1.8 {q8-q9}, [\rk] @ load first 2 round keys
vld1.8 {q14}, [ip] @ load last round key
.endm
/*
* aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks)
* aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks)
*/
ENTRY(ce_aes_ecb_encrypt)
push {r4, lr}
ldr r4, [sp, #8]
prepare_key r2, r3
.Lecbencloop3x:
subs r4, r4, #3
bmi .Lecbenc1x
vld1.8 {q0-q1}, [r1, :64]!
vld1.8 {q2}, [r1, :64]!
bl aes_encrypt_3x
vst1.8 {q0-q1}, [r0, :64]!
vst1.8 {q2}, [r0, :64]!
b .Lecbencloop3x
.Lecbenc1x:
adds r4, r4, #3
beq .Lecbencout
.Lecbencloop:
vld1.8 {q0}, [r1, :64]!
bl aes_encrypt
vst1.8 {q0}, [r0, :64]!
subs r4, r4, #1
bne .Lecbencloop
.Lecbencout:
pop {r4, pc}
ENDPROC(ce_aes_ecb_encrypt)
ENTRY(ce_aes_ecb_decrypt)
push {r4, lr}
ldr r4, [sp, #8]
prepare_key r2, r3
.Lecbdecloop3x:
subs r4, r4, #3
bmi .Lecbdec1x
vld1.8 {q0-q1}, [r1, :64]!
vld1.8 {q2}, [r1, :64]!
bl aes_decrypt_3x
vst1.8 {q0-q1}, [r0, :64]!
vst1.8 {q2}, [r0, :64]!
b .Lecbdecloop3x
.Lecbdec1x:
adds r4, r4, #3
beq .Lecbdecout
.Lecbdecloop:
vld1.8 {q0}, [r1, :64]!
bl aes_decrypt
vst1.8 {q0}, [r0, :64]!
subs r4, r4, #1
bne .Lecbdecloop
.Lecbdecout:
pop {r4, pc}
ENDPROC(ce_aes_ecb_decrypt)
/*
* aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 iv[])
* aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 iv[])
*/
ENTRY(ce_aes_cbc_encrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
vld1.8 {q0}, [r5]
prepare_key r2, r3
.Lcbcencloop:
vld1.8 {q1}, [r1, :64]! @ get next pt block
veor q0, q0, q1 @ ..and xor with iv
bl aes_encrypt
vst1.8 {q0}, [r0, :64]!
subs r4, r4, #1
bne .Lcbcencloop
vst1.8 {q0}, [r5]
pop {r4-r6, pc}
ENDPROC(ce_aes_cbc_encrypt)
ENTRY(ce_aes_cbc_decrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
vld1.8 {q6}, [r5] @ keep iv in q6
prepare_key r2, r3
.Lcbcdecloop3x:
subs r4, r4, #3
bmi .Lcbcdec1x
vld1.8 {q0-q1}, [r1, :64]!
vld1.8 {q2}, [r1, :64]!
vmov q3, q0
vmov q4, q1
vmov q5, q2
bl aes_decrypt_3x
veor q0, q0, q6
veor q1, q1, q3
veor q2, q2, q4
vmov q6, q5
vst1.8 {q0-q1}, [r0, :64]!
vst1.8 {q2}, [r0, :64]!
b .Lcbcdecloop3x
.Lcbcdec1x:
adds r4, r4, #3
beq .Lcbcdecout
vmov q15, q14 @ preserve last round key
.Lcbcdecloop:
vld1.8 {q0}, [r1, :64]! @ get next ct block
veor q14, q15, q6 @ combine prev ct with last key
vmov q6, q0
bl aes_decrypt
vst1.8 {q0}, [r0, :64]!
subs r4, r4, #1
bne .Lcbcdecloop
.Lcbcdecout:
vst1.8 {q6}, [r5] @ keep iv in q6
pop {r4-r6, pc}
ENDPROC(ce_aes_cbc_decrypt)
/*
* aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 ctr[])
*/
ENTRY(ce_aes_ctr_encrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
vld1.8 {q6}, [r5] @ load ctr
prepare_key r2, r3
vmov r6, s27 @ keep swabbed ctr in r6
rev r6, r6
cmn r6, r4 @ 32 bit overflow?
bcs .Lctrloop
.Lctrloop3x:
subs r4, r4, #3
bmi .Lctr1x
add r6, r6, #1
vmov q0, q6
vmov q1, q6
rev ip, r6
add r6, r6, #1
vmov q2, q6
vmov s7, ip
rev ip, r6
add r6, r6, #1
vmov s11, ip
vld1.8 {q3-q4}, [r1, :64]!
vld1.8 {q5}, [r1, :64]!
bl aes_encrypt_3x
veor q0, q0, q3
veor q1, q1, q4
veor q2, q2, q5
rev ip, r6
vst1.8 {q0-q1}, [r0, :64]!
vst1.8 {q2}, [r0, :64]!
vmov s27, ip
b .Lctrloop3x
.Lctr1x:
adds r4, r4, #3
beq .Lctrout
.Lctrloop:
vmov q0, q6
bl aes_encrypt
subs r4, r4, #1
bmi .Lctrhalfblock @ blocks < 0 means 1/2 block
vld1.8 {q3}, [r1, :64]!
veor q3, q0, q3
vst1.8 {q3}, [r0, :64]!
adds r6, r6, #1 @ increment BE ctr
rev ip, r6
vmov s27, ip
bcs .Lctrcarry
teq r4, #0
bne .Lctrloop
.Lctrout:
vst1.8 {q6}, [r5]
pop {r4-r6, pc}
.Lctrhalfblock:
vld1.8 {d1}, [r1, :64]
veor d0, d0, d1
vst1.8 {d0}, [r0, :64]
pop {r4-r6, pc}
.Lctrcarry:
.irp sreg, s26, s25, s24
vmov ip, \sreg @ load next word of ctr
rev ip, ip @ ... to handle the carry
adds ip, ip, #1
rev ip, ip
vmov \sreg, ip
bcc 0f
.endr
0: teq r4, #0
beq .Lctrout
b .Lctrloop
ENDPROC(ce_aes_ctr_encrypt)
/*
* aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
* int blocks, u8 iv[], u8 const rk2[], int first)
* aes_xts_decrypt(u8 out[], u8 const in[], u8 const rk1[], int rounds,
* int blocks, u8 iv[], u8 const rk2[], int first)
*/
.macro next_tweak, out, in, const, tmp
vshr.s64 \tmp, \in, #63
vand \tmp, \tmp, \const
vadd.u64 \out, \in, \in
vext.8 \tmp, \tmp, \tmp, #8
veor \out, \out, \tmp
.endm
.align 3
.Lxts_mul_x:
.quad 1, 0x87
ce_aes_xts_init:
vldr d14, .Lxts_mul_x
vldr d15, .Lxts_mul_x + 8
ldrd r4, r5, [sp, #16] @ load args
ldr r6, [sp, #28]
vld1.8 {q0}, [r5] @ load iv
teq r6, #1 @ start of a block?
bxne lr
@ Encrypt the IV in q0 with the second AES key. This should only
@ be done at the start of a block.
ldr r6, [sp, #24] @ load AES key 2
prepare_key r6, r3
add ip, r6, #32 @ 3rd round key of key 2
b .Laes_encrypt_tweak @ tail call
ENDPROC(ce_aes_xts_init)
ENTRY(ce_aes_xts_encrypt)
push {r4-r6, lr}
bl ce_aes_xts_init @ run shared prologue
prepare_key r2, r3
vmov q3, q0
teq r6, #0 @ start of a block?
bne .Lxtsenc3x
.Lxtsencloop3x:
next_tweak q3, q3, q7, q6
.Lxtsenc3x:
subs r4, r4, #3
bmi .Lxtsenc1x
vld1.8 {q0-q1}, [r1, :64]! @ get 3 pt blocks
vld1.8 {q2}, [r1, :64]!
next_tweak q4, q3, q7, q6
veor q0, q0, q3
next_tweak q5, q4, q7, q6
veor q1, q1, q4
veor q2, q2, q5
bl aes_encrypt_3x
veor q0, q0, q3
veor q1, q1, q4
veor q2, q2, q5
vst1.8 {q0-q1}, [r0, :64]! @ write 3 ct blocks
vst1.8 {q2}, [r0, :64]!
vmov q3, q5
teq r4, #0
beq .Lxtsencout
b .Lxtsencloop3x
.Lxtsenc1x:
adds r4, r4, #3
beq .Lxtsencout
.Lxtsencloop:
vld1.8 {q0}, [r1, :64]!
veor q0, q0, q3
bl aes_encrypt
veor q0, q0, q3
vst1.8 {q0}, [r0, :64]!
subs r4, r4, #1
beq .Lxtsencout
next_tweak q3, q3, q7, q6
b .Lxtsencloop
.Lxtsencout:
vst1.8 {q3}, [r5]
pop {r4-r6, pc}
ENDPROC(ce_aes_xts_encrypt)
ENTRY(ce_aes_xts_decrypt)
push {r4-r6, lr}
bl ce_aes_xts_init @ run shared prologue
prepare_key r2, r3
vmov q3, q0
teq r6, #0 @ start of a block?
bne .Lxtsdec3x
.Lxtsdecloop3x:
next_tweak q3, q3, q7, q6
.Lxtsdec3x:
subs r4, r4, #3
bmi .Lxtsdec1x
vld1.8 {q0-q1}, [r1, :64]! @ get 3 ct blocks
vld1.8 {q2}, [r1, :64]!
next_tweak q4, q3, q7, q6
veor q0, q0, q3
next_tweak q5, q4, q7, q6
veor q1, q1, q4
veor q2, q2, q5
bl aes_decrypt_3x
veor q0, q0, q3
veor q1, q1, q4
veor q2, q2, q5
vst1.8 {q0-q1}, [r0, :64]! @ write 3 pt blocks
vst1.8 {q2}, [r0, :64]!
vmov q3, q5
teq r4, #0
beq .Lxtsdecout
b .Lxtsdecloop3x
.Lxtsdec1x:
adds r4, r4, #3
beq .Lxtsdecout
.Lxtsdecloop:
vld1.8 {q0}, [r1, :64]!
veor q0, q0, q3
add ip, r2, #32 @ 3rd round key
bl aes_decrypt
veor q0, q0, q3
vst1.8 {q0}, [r0, :64]!
subs r4, r4, #1
beq .Lxtsdecout
next_tweak q3, q3, q7, q6
b .Lxtsdecloop
.Lxtsdecout:
vst1.8 {q3}, [r5]
pop {r4-r6, pc}
ENDPROC(ce_aes_xts_decrypt)
/*
* u32 ce_aes_sub(u32 input) - use the aese instruction to perform the
* AES sbox substitution on each byte in
* 'input'
*/
ENTRY(ce_aes_sub)
vdup.32 q1, r0
veor q0, q0, q0
aese.8 q0, q1
vmov r0, s0
bx lr
ENDPROC(ce_aes_sub)
/*
* void ce_aes_invert(u8 *dst, u8 *src) - perform the Inverse MixColumns
* operation on round key *src
*/
ENTRY(ce_aes_invert)
vld1.8 {q0}, [r1]
aesimc.8 q0, q0
vst1.8 {q0}, [r0]
bx lr
ENDPROC(ce_aes_invert)