/* rijndael-arm.S - ARM assembly implementation of AES cipher
*
* Copyright (C) 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#if defined(__ARMEL__)
#ifdef HAVE_COMPATIBLE_GCC_ARM_PLATFORM_AS
.text
.syntax unified
.arm
/* register macros */
#define CTX %r0
#define RTAB %lr
#define RMASK %ip
#define RA %r4
#define RB %r5
#define RC %r6
#define RD %r7
#define RNA %r8
#define RNB %r9
#define RNC %r10
#define RND %r11
#define RT0 %r1
#define RT1 %r2
#define RT2 %r3
/* helper macros */
#define ldr_unaligned_le(rout, rsrc, offs, rtmp) \
ldrb rout, [rsrc, #((offs) + 0)]; \
ldrb rtmp, [rsrc, #((offs) + 1)]; \
orr rout, rout, rtmp, lsl #8; \
ldrb rtmp, [rsrc, #((offs) + 2)]; \
orr rout, rout, rtmp, lsl #16; \
ldrb rtmp, [rsrc, #((offs) + 3)]; \
orr rout, rout, rtmp, lsl #24;
#define str_unaligned_le(rin, rdst, offs, rtmp0, rtmp1) \
mov rtmp0, rin, lsr #8; \
strb rin, [rdst, #((offs) + 0)]; \
mov rtmp1, rin, lsr #16; \
strb rtmp0, [rdst, #((offs) + 1)]; \
mov rtmp0, rin, lsr #24; \
strb rtmp1, [rdst, #((offs) + 2)]; \
strb rtmp0, [rdst, #((offs) + 3)];
/***********************************************************************
* ARM assembly implementation of the AES cipher
***********************************************************************/
#define preload_first_key(round, ra) \
ldr ra, [CTX, #(((round) * 16) + 0 * 4)];
#define dummy(round, ra) /* nothing */
#define addroundkey(ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key) \
ldm CTX, {rna, rnb, rnc, rnd}; \
eor ra, rna; \
eor rb, rnb; \
eor rc, rnc; \
preload_key(1, rna); \
eor rd, rnd;
#define do_encround(next_r, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key) \
ldr rnb, [CTX, #(((next_r) * 16) + 1 * 4)]; \
\
and RT0, RMASK, ra, lsl#2; \
ldr rnc, [CTX, #(((next_r) * 16) + 2 * 4)]; \
and RT1, RMASK, ra, lsr#(8 - 2); \
ldr rnd, [CTX, #(((next_r) * 16) + 3 * 4)]; \
and RT2, RMASK, ra, lsr#(16 - 2); \
ldr RT0, [RTAB, RT0]; \
and ra, RMASK, ra, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rna, rna, RT0; \
ldr RT2, [RTAB, RT2]; \
and RT0, RMASK, rd, lsl#2; \
ldr ra, [RTAB, ra]; \
\
eor rnd, rnd, RT1, ror #24; \
and RT1, RMASK, rd, lsr#(8 - 2); \
eor rnc, rnc, RT2, ror #16; \
and RT2, RMASK, rd, lsr#(16 - 2); \
eor rnb, rnb, ra, ror #8; \
ldr RT0, [RTAB, RT0]; \
and rd, RMASK, rd, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rnd, rnd, RT0; \
ldr RT2, [RTAB, RT2]; \
and RT0, RMASK, rc, lsl#2; \
ldr rd, [RTAB, rd]; \
\
eor rnc, rnc, RT1, ror #24; \
and RT1, RMASK, rc, lsr#(8 - 2); \
eor rnb, rnb, RT2, ror #16; \
and RT2, RMASK, rc, lsr#(16 - 2); \
eor rna, rna, rd, ror #8; \
ldr RT0, [RTAB, RT0]; \
and rc, RMASK, rc, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rnc, rnc, RT0; \
ldr RT2, [RTAB, RT2]; \
and RT0, RMASK, rb, lsl#2; \
ldr rc, [RTAB, rc]; \
\
eor rnb, rnb, RT1, ror #24; \
and RT1, RMASK, rb, lsr#(8 - 2); \
eor rna, rna, RT2, ror #16; \
and RT2, RMASK, rb, lsr#(16 - 2); \
eor rnd, rnd, rc, ror #8; \
ldr RT0, [RTAB, RT0]; \
and rb, RMASK, rb, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rnb, rnb, RT0; \
ldr RT2, [RTAB, RT2]; \
eor rna, rna, RT1, ror #24; \
ldr rb, [RTAB, rb]; \
\
eor rnd, rnd, RT2, ror #16; \
preload_key((next_r) + 1, ra); \
eor rnc, rnc, rb, ror #8;
#define do_lastencround(ra, rb, rc, rd, rna, rnb, rnc, rnd) \
and RT0, RMASK, ra, lsl#2; \
and RT1, RMASK, ra, lsr#(8 - 2); \
and RT2, RMASK, ra, lsr#(16 - 2); \
ldrb rna, [RTAB, RT0]; \
and ra, RMASK, ra, lsr#(24 - 2); \
ldrb rnd, [RTAB, RT1]; \
and RT0, RMASK, rd, lsl#2; \
ldrb rnc, [RTAB, RT2]; \
mov rnd, rnd, ror #24; \
ldrb rnb, [RTAB, ra]; \
and RT1, RMASK, rd, lsr#(8 - 2); \
mov rnc, rnc, ror #16; \
and RT2, RMASK, rd, lsr#(16 - 2); \
mov rnb, rnb, ror #8; \
ldrb RT0, [RTAB, RT0]; \
and rd, RMASK, rd, lsr#(24 - 2); \
ldrb RT1, [RTAB, RT1]; \
\
orr rnd, rnd, RT0; \
ldrb RT2, [RTAB, RT2]; \
and RT0, RMASK, rc, lsl#2; \
ldrb rd, [RTAB, rd]; \
orr rnc, rnc, RT1, ror #24; \
and RT1, RMASK, rc, lsr#(8 - 2); \
orr rnb, rnb, RT2, ror #16; \
and RT2, RMASK, rc, lsr#(16 - 2); \
orr rna, rna, rd, ror #8; \
ldrb RT0, [RTAB, RT0]; \
and rc, RMASK, rc, lsr#(24 - 2); \
ldrb RT1, [RTAB, RT1]; \
\
orr rnc, rnc, RT0; \
ldrb RT2, [RTAB, RT2]; \
and RT0, RMASK, rb, lsl#2; \
ldrb rc, [RTAB, rc]; \
orr rnb, rnb, RT1, ror #24; \
and RT1, RMASK, rb, lsr#(8 - 2); \
orr rna, rna, RT2, ror #16; \
ldrb RT0, [RTAB, RT0]; \
and RT2, RMASK, rb, lsr#(16 - 2); \
ldrb RT1, [RTAB, RT1]; \
orr rnd, rnd, rc, ror #8; \
ldrb RT2, [RTAB, RT2]; \
and rb, RMASK, rb, lsr#(24 - 2); \
ldrb rb, [RTAB, rb]; \
\
orr rnb, rnb, RT0; \
orr rna, rna, RT1, ror #24; \
orr rnd, rnd, RT2, ror #16; \
orr rnc, rnc, rb, ror #8;
#define firstencround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd) \
addroundkey(ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_first_key); \
do_encround((round) + 1, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_first_key);
#define encround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key) \
do_encround((round) + 1, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key);
#define lastencround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd) \
add CTX, #(((round) + 1) * 16); \
add RTAB, #1; \
do_lastencround(ra, rb, rc, rd, rna, rnb, rnc, rnd); \
addroundkey(rna, rnb, rnc, rnd, ra, rb, rc, rd, dummy);
.align 3
.globl _gcry_aes_arm_encrypt_block
.type _gcry_aes_arm_encrypt_block,%function;
_gcry_aes_arm_encrypt_block:
/* input:
* %r0: keysched, CTX
* %r1: dst
* %r2: src
* %r3: number of rounds.. 10, 12 or 14
* %st+0: encryption table
*/
push {%r4-%r11, %ip, %lr};
/* read input block */
/* test if src is unaligned */
tst %r2, #3;
beq 1f;
/* unaligned load */
ldr_unaligned_le(RA, %r2, 0, RNA);
ldr_unaligned_le(RB, %r2, 4, RNB);
ldr_unaligned_le(RC, %r2, 8, RNA);
ldr_unaligned_le(RD, %r2, 12, RNB);
b 2f;
.ltorg
1:
/* aligned load */
ldm %r2, {RA, RB, RC, RD};
#ifndef __ARMEL__
rev RA, RA;
rev RB, RB;
rev RC, RC;
rev RD, RD;
#endif
2:
ldr RTAB, [%sp, #40];
sub %sp, #16;
str %r1, [%sp, #4]; /* dst */
mov RMASK, #0xff;
str %r3, [%sp, #8]; /* nrounds */
mov RMASK, RMASK, lsl#2; /* byte mask */
firstencround(0, RA, RB, RC, RD, RNA, RNB, RNC, RND);
encround(1, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
encround(2, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
encround(3, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
encround(4, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
encround(5, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
encround(6, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
encround(7, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
ldr RT0, [%sp, #8]; /* nrounds */
cmp RT0, #12;
bge .Lenc_not_128;
encround(8, RA, RB, RC, RD, RNA, RNB, RNC, RND, dummy);
lastencround(9, RNA, RNB, RNC, RND, RA, RB, RC, RD);
.Lenc_done:
ldr RT0, [%sp, #4]; /* dst */
add %sp, #16;
/* store output block */
/* test if dst is unaligned */
tst RT0, #3;
beq 1f;
/* unaligned store */
str_unaligned_le(RA, RT0, 0, RNA, RNB);
str_unaligned_le(RB, RT0, 4, RNA, RNB);
str_unaligned_le(RC, RT0, 8, RNA, RNB);
str_unaligned_le(RD, RT0, 12, RNA, RNB);
b 2f;
.ltorg
1:
/* aligned store */
#ifndef __ARMEL__
rev RA, RA;
rev RB, RB;
rev RC, RC;
rev RD, RD;
#endif
/* write output block */
stm RT0, {RA, RB, RC, RD};
2:
mov r0, #(10 * 4);
pop {%r4-%r11, %ip, %pc};
.ltorg
.Lenc_not_128:
beq .Lenc_192
encround(8, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
encround(9, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
encround(10, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
encround(11, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
encround(12, RA, RB, RC, RD, RNA, RNB, RNC, RND, dummy);
lastencround(13, RNA, RNB, RNC, RND, RA, RB, RC, RD);
b .Lenc_done;
.ltorg
.Lenc_192:
encround(8, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
encround(9, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
encround(10, RA, RB, RC, RD, RNA, RNB, RNC, RND, dummy);
lastencround(11, RNA, RNB, RNC, RND, RA, RB, RC, RD);
b .Lenc_done;
.size _gcry_aes_arm_encrypt_block,.-_gcry_aes_arm_encrypt_block;
#define addroundkey_dec(round, ra, rb, rc, rd, rna, rnb, rnc, rnd) \
ldr rna, [CTX, #(((round) * 16) + 0 * 4)]; \
ldr rnb, [CTX, #(((round) * 16) + 1 * 4)]; \
eor ra, rna; \
ldr rnc, [CTX, #(((round) * 16) + 2 * 4)]; \
eor rb, rnb; \
ldr rnd, [CTX, #(((round) * 16) + 3 * 4)]; \
eor rc, rnc; \
preload_first_key((round) - 1, rna); \
eor rd, rnd;
#define do_decround(next_r, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key) \
ldr rnb, [CTX, #(((next_r) * 16) + 1 * 4)]; \
\
and RT0, RMASK, ra, lsl#2; \
ldr rnc, [CTX, #(((next_r) * 16) + 2 * 4)]; \
and RT1, RMASK, ra, lsr#(8 - 2); \
ldr rnd, [CTX, #(((next_r) * 16) + 3 * 4)]; \
and RT2, RMASK, ra, lsr#(16 - 2); \
ldr RT0, [RTAB, RT0]; \
and ra, RMASK, ra, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rna, rna, RT0; \
ldr RT2, [RTAB, RT2]; \
and RT0, RMASK, rb, lsl#2; \
ldr ra, [RTAB, ra]; \
\
eor rnb, rnb, RT1, ror #24; \
and RT1, RMASK, rb, lsr#(8 - 2); \
eor rnc, rnc, RT2, ror #16; \
and RT2, RMASK, rb, lsr#(16 - 2); \
eor rnd, rnd, ra, ror #8; \
ldr RT0, [RTAB, RT0]; \
and rb, RMASK, rb, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rnb, rnb, RT0; \
ldr RT2, [RTAB, RT2]; \
and RT0, RMASK, rc, lsl#2; \
ldr rb, [RTAB, rb]; \
\
eor rnc, rnc, RT1, ror #24; \
and RT1, RMASK, rc, lsr#(8 - 2); \
eor rnd, rnd, RT2, ror #16; \
and RT2, RMASK, rc, lsr#(16 - 2); \
eor rna, rna, rb, ror #8; \
ldr RT0, [RTAB, RT0]; \
and rc, RMASK, rc, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rnc, rnc, RT0; \
ldr RT2, [RTAB, RT2]; \
and RT0, RMASK, rd, lsl#2; \
ldr rc, [RTAB, rc]; \
\
eor rnd, rnd, RT1, ror #24; \
and RT1, RMASK, rd, lsr#(8 - 2); \
eor rna, rna, RT2, ror #16; \
and RT2, RMASK, rd, lsr#(16 - 2); \
eor rnb, rnb, rc, ror #8; \
ldr RT0, [RTAB, RT0]; \
and rd, RMASK, rd, lsr#(24 - 2); \
\
ldr RT1, [RTAB, RT1]; \
eor rnd, rnd, RT0; \
ldr RT2, [RTAB, RT2]; \
eor rna, rna, RT1, ror #24; \
ldr rd, [RTAB, rd]; \
\
eor rnb, rnb, RT2, ror #16; \
preload_key((next_r) - 1, ra); \
eor rnc, rnc, rd, ror #8;
#define do_lastdecround(ra, rb, rc, rd, rna, rnb, rnc, rnd) \
and RT0, RMASK, ra; \
and RT1, RMASK, ra, lsr#8; \
and RT2, RMASK, ra, lsr#16; \
ldrb rna, [RTAB, RT0]; \
mov ra, ra, lsr#24; \
ldrb rnb, [RTAB, RT1]; \
and RT0, RMASK, rb; \
ldrb rnc, [RTAB, RT2]; \
mov rnb, rnb, ror #24; \
ldrb rnd, [RTAB, ra]; \
and RT1, RMASK, rb, lsr#8; \
mov rnc, rnc, ror #16; \
and RT2, RMASK, rb, lsr#16; \
mov rnd, rnd, ror #8; \
ldrb RT0, [RTAB, RT0]; \
mov rb, rb, lsr#24; \
ldrb RT1, [RTAB, RT1]; \
\
orr rnb, rnb, RT0; \
ldrb RT2, [RTAB, RT2]; \
and RT0, RMASK, rc; \
ldrb rb, [RTAB, rb]; \
orr rnc, rnc, RT1, ror #24; \
and RT1, RMASK, rc, lsr#8; \
orr rnd, rnd, RT2, ror #16; \
and RT2, RMASK, rc, lsr#16; \
orr rna, rna, rb, ror #8; \
ldrb RT0, [RTAB, RT0]; \
mov rc, rc, lsr#24; \
ldrb RT1, [RTAB, RT1]; \
\
orr rnc, rnc, RT0; \
ldrb RT2, [RTAB, RT2]; \
and RT0, RMASK, rd; \
ldrb rc, [RTAB, rc]; \
orr rnd, rnd, RT1, ror #24; \
and RT1, RMASK, rd, lsr#8; \
orr rna, rna, RT2, ror #16; \
ldrb RT0, [RTAB, RT0]; \
and RT2, RMASK, rd, lsr#16; \
ldrb RT1, [RTAB, RT1]; \
orr rnb, rnb, rc, ror #8; \
ldrb RT2, [RTAB, RT2]; \
mov rd, rd, lsr#24; \
ldrb rd, [RTAB, rd]; \
\
orr rnd, rnd, RT0; \
orr rna, rna, RT1, ror #24; \
orr rnb, rnb, RT2, ror #16; \
orr rnc, rnc, rd, ror #8;
#define firstdecround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd) \
addroundkey_dec(((round) + 1), ra, rb, rc, rd, rna, rnb, rnc, rnd); \
do_decround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_first_key);
#define decround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key) \
do_decround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd, preload_key);
#define set_last_round_rmask(_, __) \
mov RMASK, #0xff;
#define lastdecround(round, ra, rb, rc, rd, rna, rnb, rnc, rnd) \
add RTAB, #(4 * 256); \
do_lastdecround(ra, rb, rc, rd, rna, rnb, rnc, rnd); \
addroundkey(rna, rnb, rnc, rnd, ra, rb, rc, rd, dummy);
.align 3
.globl _gcry_aes_arm_decrypt_block
.type _gcry_aes_arm_decrypt_block,%function;
_gcry_aes_arm_decrypt_block:
/* input:
* %r0: keysched, CTX
* %r1: dst
* %r2: src
* %r3: number of rounds.. 10, 12 or 14
* %st+0: decryption table
*/
push {%r4-%r11, %ip, %lr};
/* read input block */
/* test if src is unaligned */
tst %r2, #3;
beq 1f;
/* unaligned load */
ldr_unaligned_le(RA, %r2, 0, RNA);
ldr_unaligned_le(RB, %r2, 4, RNB);
ldr_unaligned_le(RC, %r2, 8, RNA);
ldr_unaligned_le(RD, %r2, 12, RNB);
b 2f;
.ltorg
1:
/* aligned load */
ldm %r2, {RA, RB, RC, RD};
#ifndef __ARMEL__
rev RA, RA;
rev RB, RB;
rev RC, RC;
rev RD, RD;
#endif
2:
ldr RTAB, [%sp, #40];
sub %sp, #16;
mov RMASK, #0xff;
str %r1, [%sp, #4]; /* dst */
mov RMASK, RMASK, lsl#2; /* byte mask */
cmp %r3, #12;
bge .Ldec_256;
firstdecround(9, RA, RB, RC, RD, RNA, RNB, RNC, RND);
.Ldec_tail:
decround(8, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(7, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
decround(6, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(5, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
decround(4, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(3, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
decround(2, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(1, RA, RB, RC, RD, RNA, RNB, RNC, RND, set_last_round_rmask);
lastdecround(0, RNA, RNB, RNC, RND, RA, RB, RC, RD);
ldr RT0, [%sp, #4]; /* dst */
add %sp, #16;
/* store output block */
/* test if dst is unaligned */
tst RT0, #3;
beq 1f;
/* unaligned store */
str_unaligned_le(RA, RT0, 0, RNA, RNB);
str_unaligned_le(RB, RT0, 4, RNA, RNB);
str_unaligned_le(RC, RT0, 8, RNA, RNB);
str_unaligned_le(RD, RT0, 12, RNA, RNB);
b 2f;
.ltorg
1:
/* aligned store */
#ifndef __ARMEL__
rev RA, RA;
rev RB, RB;
rev RC, RC;
rev RD, RD;
#endif
/* write output block */
stm RT0, {RA, RB, RC, RD};
2:
mov r0, #(10 * 4);
pop {%r4-%r11, %ip, %pc};
.ltorg
.Ldec_256:
beq .Ldec_192;
firstdecround(13, RA, RB, RC, RD, RNA, RNB, RNC, RND);
decround(12, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(11, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
decround(10, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(9, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
b .Ldec_tail;
.ltorg
.Ldec_192:
firstdecround(11, RA, RB, RC, RD, RNA, RNB, RNC, RND);
decround(10, RNA, RNB, RNC, RND, RA, RB, RC, RD, preload_first_key);
decround(9, RA, RB, RC, RD, RNA, RNB, RNC, RND, preload_first_key);
b .Ldec_tail;
.size _gcry_aes_arm_encrypt_block,.-_gcry_aes_arm_encrypt_block;
#endif /*HAVE_COMPATIBLE_GCC_ARM_PLATFORM_AS*/
#endif /*__ARMEL__ */