234 lines
3.4 KiB
ArmAsm
234 lines
3.4 KiB
ArmAsm
/* aes_enc-asm.S */
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/*
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This file is part of the AVR-Crypto-Lib.
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Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* \file aes_enc-asm.S
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* \email bg@nerilex.org
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* \author Daniel Otte
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* \date 2009-01-10
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* \license GPLv3 or later
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*
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*/
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#include "avr-asm-macros.S"
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/*
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* param a: r24
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* param b: r22
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* param reducer: r0
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*/
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A = 28
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B = 29
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P = 0
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xREDUCER = 25
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.global aes256_enc
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aes256_enc:
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ldi r20, 14
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rjmp aes_encrypt_core
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.global aes192_enc
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aes192_enc:
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ldi r20, 12
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rjmp aes_encrypt_core
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.global aes128_enc
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aes128_enc:
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ldi r20, 10
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/*
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void aes_encrypt_core(aes_cipher_state_t *state, const aes_genctx_t *ks, uint8_t rounds)
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*/
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T0= 2
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T1= 3
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T2= 4
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T3= 5
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SBOX_SAVE0 = 6
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SBOX_SAVE1 = 7
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ST00 = 8
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ST01 = 9
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ST02 = 10
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ST03 = 11
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ST10 = 12
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ST11 = 13
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ST12 = 14
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ST13 = 15
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ST20 = 16
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ST21 = 17
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ST22 = 18
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ST23 = 19
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ST30 = 20
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ST31 = 21
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ST32 = 22
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ST33 = 23
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CTR = 24
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/*
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* param state: r24:r25
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* param ks: r22:r23
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* param rounds: r20
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*/
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.global aes_encrypt_core
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aes_encrypt_core:
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push_range 2, 17
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push r28
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push r29
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push r24
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push r25
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movw r26, r22
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movw r30, r24
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mov CTR, r20
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clt
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.irp row, 0, 1, 2, 3
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.irp col, 0, 1, 2, 3
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ld ST\row\col, Z+
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.endr
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.endr
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ldi xREDUCER, 0x1b /* load reducer */
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ldi r31, hi8(aes_sbox)
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/* key whitening */
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1:
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.irp row, 0, 1, 2, 3
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.irp col, 0, 1, 2, 3
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ld r0, X+
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eor ST\row\col, r0
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.endr
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.endr
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brtc 2f
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exit:
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pop r31
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pop r30
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.irp row, 0, 1, 2, 3
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.irp col, 0, 1, 2, 3
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st Z+, ST\row\col
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.endr
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.endr
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pop r29
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pop r28
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pop_range 2, 17
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ret
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2: dec CTR
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brne 3f
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set
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3:
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/* encryption loop */
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/* SBOX substitution and shifting */
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mov r30, ST00
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lpm ST00, Z
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mov r30, ST10
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lpm ST10, Z
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mov r30, ST20
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lpm ST20, Z
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mov r30, ST30
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lpm ST30, Z
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mov r30, ST01
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lpm T0, Z
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mov r30, ST11
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lpm ST01, Z
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mov r30, ST21
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lpm ST11, Z
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mov r30, ST31
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lpm ST21, Z
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mov ST31, T0
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mov r30, ST02
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lpm T0, Z
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mov r30, ST12
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lpm T1, Z
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mov r30, ST22
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lpm ST02, Z
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mov r30, ST32
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lpm ST12, Z
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mov ST22, T0
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mov ST32, T1
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mov r30, ST03
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lpm T0, Z
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mov r30, ST33
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lpm ST03, Z
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mov r30, ST23
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lpm ST33, Z
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mov r30, ST13
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lpm ST23, Z
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mov ST13, T0
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/* mixcols (or rows in our case) */
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brtc 2f
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rjmp 1b
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2:
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/* mixrows */
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.irp row, 0, 1, 2, 3
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mov r0, ST\row\()2
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eor r0, ST\row\()3
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mov T2, r0
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mov T0, ST\row\()0
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eor ST\row\()0, ST\row\()1
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eor r0, ST\row\()0
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lsl ST\row\()0
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brcc 3f
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eor ST\row\()0, xREDUCER
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3: eor ST\row\()0, r0
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eor ST\row\()0, T0
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mov T1, ST\row\()1
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eor T1, ST\row\()2
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lsl T1
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brcc 3f
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eor T1, xREDUCER
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3: eor T1, r0
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eor ST\row\()1, T1
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lsl T2
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brcc 3f
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eor T2, xREDUCER
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3: eor T2, r0
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eor ST\row\()2, T2
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eor T0, ST\row\()3
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lsl T0
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brcc 3f
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eor T0, xREDUCER
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3: eor T0, r0
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eor ST\row\()3, T0
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.endr
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/* mix colums (rows) done */
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/* add key*/
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rjmp 1b
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