426 lines
6.0 KiB
ArmAsm
426 lines
6.0 KiB
ArmAsm
/* aes_dec-asm.S */
|
|
/*
|
|
This file is part of the AVR-Crypto-Lib.
|
|
Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
/**
|
|
* \file aes_dec-asm.S
|
|
* \email bg@nerilex.org
|
|
* \author Daniel Otte
|
|
* \date 2009-01-10
|
|
* \license GPLv3 or later
|
|
*
|
|
*/
|
|
|
|
#include "avr-asm-macros.S"
|
|
A = 28
|
|
B = 29
|
|
P = 0
|
|
xREDUCER = 25
|
|
gf256mul:
|
|
clr P
|
|
1:
|
|
lsr A
|
|
breq 4f
|
|
brcc 2f
|
|
eor P, B
|
|
2:
|
|
lsl B
|
|
brcc 3f
|
|
eor B, xREDUCER
|
|
3:
|
|
rjmp 1b
|
|
4:
|
|
brcc 2f
|
|
eor P, B
|
|
2:
|
|
ret
|
|
|
|
.global aes256_dec
|
|
aes256_dec:
|
|
ldi r20, 14
|
|
rjmp aes_decrypt_core
|
|
|
|
.global aes192_dec
|
|
aes192_dec:
|
|
ldi r20, 12
|
|
rjmp aes_decrypt_core
|
|
|
|
.global aes128_dec
|
|
aes128_dec:
|
|
ldi r20, 10
|
|
|
|
|
|
/*
|
|
void aes_decrypt_core(aes_cipher_state_t *state, const aes_genctx_t *ks, uint8_t rounds)
|
|
*/
|
|
T0= 2
|
|
T1= 3
|
|
T2= 4
|
|
T3= 5
|
|
T4 = 6
|
|
T5 = 7
|
|
ST00 = 8
|
|
ST01 = 9
|
|
ST02 = 10
|
|
ST03 = 11
|
|
ST10 = 12
|
|
ST11 = 13
|
|
ST12 = 14
|
|
ST13 = 15
|
|
ST20 = 16
|
|
ST21 = 17
|
|
ST22 = 18
|
|
ST23 = 19
|
|
ST30 = 20
|
|
ST31 = 21
|
|
ST32 = 22
|
|
ST33 = 23
|
|
CTR = 24
|
|
/*
|
|
* param state: r24:r25
|
|
* param ks: r22:r23
|
|
* param rounds: r20
|
|
*/
|
|
.global aes_decrypt_core
|
|
aes_decrypt_core:
|
|
push_range 2, 17
|
|
push r28
|
|
push r29
|
|
push r24
|
|
push r25
|
|
movw r26, r22
|
|
movw r30, r24
|
|
mov CTR, r20
|
|
inc r20
|
|
swap r20 /* r20*16 */
|
|
add r26, r20
|
|
adc r27, r1
|
|
clt
|
|
; ldi CTR, 2
|
|
.irp param, ST00, ST01, ST02, ST03, ST10, ST11, ST12, ST13, ST20, ST21, ST22, ST23, ST30, ST31, ST32, ST33
|
|
ld \param, Z+
|
|
.endr
|
|
|
|
ldi xREDUCER, 0x1b /* load reducer */
|
|
ldi r31, hi8(aes_invsbox)
|
|
|
|
|
|
.irp param, ST33, ST32, ST31, ST30, ST23, ST22, ST21, ST20, ST13, ST12, ST11, ST10, ST03, ST02, ST01, ST00
|
|
ld r0, -X
|
|
eor \param, r0
|
|
.endr
|
|
1:
|
|
dec CTR
|
|
brne 2f
|
|
set
|
|
2:
|
|
/* substitute and invShift */
|
|
.irp param, ST00, ST10, ST20, ST30
|
|
mov r30, \param
|
|
lpm \param, Z
|
|
.endr
|
|
mov r30, ST31
|
|
lpm T0, Z
|
|
mov r30, ST21
|
|
lpm ST31, Z
|
|
mov r30, ST11
|
|
lpm ST21, Z
|
|
mov r30, ST01
|
|
lpm ST11, Z
|
|
mov ST01, T0
|
|
|
|
mov r30, ST32
|
|
lpm T0, Z
|
|
mov r30, ST22
|
|
lpm T1,Z
|
|
mov r30, ST12
|
|
lpm ST32, Z
|
|
mov r30, ST02
|
|
lpm ST22, Z
|
|
mov ST12, T0
|
|
mov ST02, T1
|
|
|
|
mov r30, ST03
|
|
lpm T0, Z
|
|
mov r30, ST13
|
|
lpm ST03, Z
|
|
mov r30, ST23
|
|
lpm ST13, Z
|
|
mov r30, ST33
|
|
lpm ST23, Z
|
|
mov ST33, T0
|
|
|
|
/* key addition */
|
|
.irp param, ST33, ST32, ST31, ST30, ST23, ST22, ST21, ST20, ST13, ST12, ST11, ST10, ST03, ST02, ST01, ST00
|
|
ld r0, -X
|
|
eor \param, r0
|
|
.endr
|
|
brtc 2f
|
|
exit:
|
|
pop r31
|
|
pop r30
|
|
st Z+, ST00
|
|
st Z+, ST01
|
|
st Z+, ST02
|
|
st Z+, ST03
|
|
st Z+, ST10
|
|
st Z+, ST11
|
|
st Z+, ST12
|
|
st Z+, ST13
|
|
st Z+, ST20
|
|
st Z+, ST21
|
|
st Z+, ST22
|
|
st Z+, ST23
|
|
st Z+, ST30
|
|
st Z+, ST31
|
|
st Z+, ST32
|
|
st Z+, ST33
|
|
pop r29
|
|
pop r28
|
|
pop_range 2, 17
|
|
ret
|
|
2:
|
|
/* inv column (row) mixing*/
|
|
/* invMixCol (Row) 1 */
|
|
/* preparing */
|
|
mov T0, ST03
|
|
eor T0, ST02 ; T0 = t
|
|
mov T1, ST00
|
|
eor T1, ST01 ; T1 = u
|
|
mov T2, T0
|
|
eor T2, T1
|
|
|
|
mov B, T2
|
|
ldi A, 0x08
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v'
|
|
|
|
mov B, ST02
|
|
eor B, ST00
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
mov T3, P
|
|
eor T3, T2; T3 = w
|
|
|
|
mov B, ST03
|
|
eor B, ST01
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v
|
|
|
|
/* now the big move */
|
|
mov T4, ST00
|
|
eor T4, ST03
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST03, T4
|
|
|
|
mov T4, ST02
|
|
eor T4, ST01
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST01, T4
|
|
|
|
lsl T0
|
|
brcc 3f
|
|
eor T0, xREDUCER
|
|
3: eor T0, T3
|
|
eor ST02, T0
|
|
|
|
lsl T1
|
|
brcc 3f
|
|
eor T1, xREDUCER
|
|
3: eor T1, T3
|
|
eor ST00, T1
|
|
|
|
/* invMixCol (Row) 2 */
|
|
/* preparing */
|
|
mov T0, ST13
|
|
eor T0, ST12 ; T0 = t
|
|
mov T1, ST10
|
|
eor T1, ST11 ; T1 = u
|
|
mov T2, T0
|
|
eor T2, T1
|
|
|
|
mov B, T2
|
|
ldi A, 0x08
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v'
|
|
|
|
mov B, ST12
|
|
eor B, ST10
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
mov T3, P
|
|
eor T3, T2; T3 = w
|
|
|
|
mov B, ST13
|
|
eor B, ST11
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v
|
|
|
|
/* now the big move */
|
|
mov T4, ST10
|
|
eor T4, ST13
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST13, T4
|
|
|
|
mov T4, ST12
|
|
eor T4, ST11
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST11, T4
|
|
|
|
lsl T0
|
|
brcc 3f
|
|
eor T0, xREDUCER
|
|
3: eor T0, T3
|
|
eor ST12, T0
|
|
|
|
lsl T1
|
|
brcc 3f
|
|
eor T1, xREDUCER
|
|
3: eor T1, T3
|
|
eor ST10, T1
|
|
|
|
/* invMixCol (Row) 2 */
|
|
/* preparing */
|
|
mov T0, ST23
|
|
eor T0, ST22 ; T0 = t
|
|
mov T1, ST20
|
|
eor T1, ST21 ; T1 = u
|
|
mov T2, T0
|
|
eor T2, T1
|
|
|
|
mov B, T2
|
|
ldi A, 0x08
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v'
|
|
|
|
mov B, ST22
|
|
eor B, ST20
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
mov T3, P
|
|
eor T3, T2; T3 = w
|
|
|
|
mov B, ST23
|
|
eor B, ST21
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v
|
|
|
|
/* now the big move */
|
|
mov T4, ST20
|
|
eor T4, ST23
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST23, T4
|
|
|
|
mov T4, ST22
|
|
eor T4, ST21
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST21, T4
|
|
|
|
lsl T0
|
|
brcc 3f
|
|
eor T0, xREDUCER
|
|
3: eor T0, T3
|
|
eor ST22, T0
|
|
|
|
lsl T1
|
|
brcc 3f
|
|
eor T1, xREDUCER
|
|
3: eor T1, T3
|
|
eor ST20, T1
|
|
|
|
/* invMixCol (Row) 3 */
|
|
/* preparing */
|
|
mov T0, ST33
|
|
eor T0, ST32 ; T0 = t
|
|
mov T1, ST30
|
|
eor T1, ST31 ; T1 = u
|
|
mov T2, T0
|
|
eor T2, T1
|
|
|
|
mov B, T2
|
|
ldi A, 0x08
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v'
|
|
|
|
mov B, ST32
|
|
eor B, ST30
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
mov T3, P
|
|
eor T3, T2; T3 = w
|
|
|
|
mov B, ST33
|
|
eor B, ST31
|
|
ldi A, 0x04
|
|
rcall gf256mul
|
|
eor T2, P ; T2 = v
|
|
|
|
/* now the big move */
|
|
mov T4, ST30
|
|
eor T4, ST33
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST33, T4
|
|
|
|
mov T4, ST32
|
|
eor T4, ST31
|
|
lsl T4
|
|
brcc 3f
|
|
eor T4, xREDUCER
|
|
3: eor T4, T2
|
|
eor ST31, T4
|
|
|
|
lsl T0
|
|
brcc 3f
|
|
eor T0, xREDUCER
|
|
3: eor T0, T3
|
|
eor ST32, T0
|
|
|
|
lsl T1
|
|
brcc 3f
|
|
eor T1, xREDUCER
|
|
3: eor T1, T3
|
|
eor ST30, T1
|
|
|
|
rjmp 1b
|
|
|
|
|
|
|