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linux-zen-desktop/arch/arm64/crypto/sm4-ce-gcm-core.S

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ArmAsm
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Initial commit
2023-08-30 17:31:07 +02:00
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* SM4-GCM AEAD Algorithm using ARMv8 Crypto Extensions
* as specified in rfc8998
* https://datatracker.ietf.org/doc/html/rfc8998
*
* Copyright (C) 2016 Jussi Kivilinna <jussi.kivilinna@iki.fi>
* Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
*/
#include <linux/linkage.h>
#include <linux/cfi_types.h>
#include <asm/assembler.h>
#include "sm4-ce-asm.h"
.arch armv8-a+crypto
.irp b, 0, 1, 2, 3, 24, 25, 26, 27, 28, 29, 30, 31
.set .Lv\b\().4s, \b
.endr
.macro sm4e, vd, vn
.inst 0xcec08400 | (.L\vn << 5) | .L\vd
.endm
/* Register macros */
/* Used for both encryption and decryption */
#define RHASH v21
#define RRCONST v22
#define RZERO v23
/* Helper macros. */
/*
* input: m0, m1
* output: r0:r1 (low 128-bits in r0, high in r1)
*/
#define PMUL_128x128(r0, r1, m0, m1, T0, T1) \
ext T0.16b, m1.16b, m1.16b, #8; \
pmull r0.1q, m0.1d, m1.1d; \
pmull T1.1q, m0.1d, T0.1d; \
pmull2 T0.1q, m0.2d, T0.2d; \
pmull2 r1.1q, m0.2d, m1.2d; \
eor T0.16b, T0.16b, T1.16b; \
ext T1.16b, RZERO.16b, T0.16b, #8; \
ext T0.16b, T0.16b, RZERO.16b, #8; \
eor r0.16b, r0.16b, T1.16b; \
eor r1.16b, r1.16b, T0.16b;
#define PMUL_128x128_4x(r0, r1, m0, m1, T0, T1, \
r2, r3, m2, m3, T2, T3, \
r4, r5, m4, m5, T4, T5, \
r6, r7, m6, m7, T6, T7) \
ext T0.16b, m1.16b, m1.16b, #8; \
ext T2.16b, m3.16b, m3.16b, #8; \
ext T4.16b, m5.16b, m5.16b, #8; \
ext T6.16b, m7.16b, m7.16b, #8; \
pmull r0.1q, m0.1d, m1.1d; \
pmull r2.1q, m2.1d, m3.1d; \
pmull r4.1q, m4.1d, m5.1d; \
pmull r6.1q, m6.1d, m7.1d; \
pmull T1.1q, m0.1d, T0.1d; \
pmull T3.1q, m2.1d, T2.1d; \
pmull T5.1q, m4.1d, T4.1d; \
pmull T7.1q, m6.1d, T6.1d; \
pmull2 T0.1q, m0.2d, T0.2d; \
pmull2 T2.1q, m2.2d, T2.2d; \
pmull2 T4.1q, m4.2d, T4.2d; \
pmull2 T6.1q, m6.2d, T6.2d; \
pmull2 r1.1q, m0.2d, m1.2d; \
pmull2 r3.1q, m2.2d, m3.2d; \
pmull2 r5.1q, m4.2d, m5.2d; \
pmull2 r7.1q, m6.2d, m7.2d; \
eor T0.16b, T0.16b, T1.16b; \
eor T2.16b, T2.16b, T3.16b; \
eor T4.16b, T4.16b, T5.16b; \
eor T6.16b, T6.16b, T7.16b; \
ext T1.16b, RZERO.16b, T0.16b, #8; \
ext T3.16b, RZERO.16b, T2.16b, #8; \
ext T5.16b, RZERO.16b, T4.16b, #8; \
ext T7.16b, RZERO.16b, T6.16b, #8; \
ext T0.16b, T0.16b, RZERO.16b, #8; \
ext T2.16b, T2.16b, RZERO.16b, #8; \
ext T4.16b, T4.16b, RZERO.16b, #8; \
ext T6.16b, T6.16b, RZERO.16b, #8; \
eor r0.16b, r0.16b, T1.16b; \
eor r2.16b, r2.16b, T3.16b; \
eor r4.16b, r4.16b, T5.16b; \
eor r6.16b, r6.16b, T7.16b; \
eor r1.16b, r1.16b, T0.16b; \
eor r3.16b, r3.16b, T2.16b; \
eor r5.16b, r5.16b, T4.16b; \
eor r7.16b, r7.16b, T6.16b;
/*
* input: r0:r1 (low 128-bits in r0, high in r1)
* output: a
*/
#define REDUCTION(a, r0, r1, rconst, T0, T1) \
pmull2 T0.1q, r1.2d, rconst.2d; \
ext T1.16b, T0.16b, RZERO.16b, #8; \
ext T0.16b, RZERO.16b, T0.16b, #8; \
eor r1.16b, r1.16b, T1.16b; \
eor r0.16b, r0.16b, T0.16b; \
pmull T0.1q, r1.1d, rconst.1d; \
eor a.16b, r0.16b, T0.16b;
#define SM4_CRYPT_PMUL_128x128_BLK(b0, r0, r1, m0, m1, T0, T1) \
rev32 b0.16b, b0.16b; \
ext T0.16b, m1.16b, m1.16b, #8; \
sm4e b0.4s, v24.4s; \
pmull r0.1q, m0.1d, m1.1d; \
sm4e b0.4s, v25.4s; \
pmull T1.1q, m0.1d, T0.1d; \
sm4e b0.4s, v26.4s; \
pmull2 T0.1q, m0.2d, T0.2d; \
sm4e b0.4s, v27.4s; \
pmull2 r1.1q, m0.2d, m1.2d; \
sm4e b0.4s, v28.4s; \
eor T0.16b, T0.16b, T1.16b; \
sm4e b0.4s, v29.4s; \
ext T1.16b, RZERO.16b, T0.16b, #8; \
sm4e b0.4s, v30.4s; \
ext T0.16b, T0.16b, RZERO.16b, #8; \
sm4e b0.4s, v31.4s; \
eor r0.16b, r0.16b, T1.16b; \
rev64 b0.4s, b0.4s; \
eor r1.16b, r1.16b, T0.16b; \
ext b0.16b, b0.16b, b0.16b, #8; \
rev32 b0.16b, b0.16b;
#define SM4_CRYPT_PMUL_128x128_BLK3(b0, b1, b2, \
r0, r1, m0, m1, T0, T1, \
r2, r3, m2, m3, T2, T3, \
r4, r5, m4, m5, T4, T5) \
rev32 b0.16b, b0.16b; \
rev32 b1.16b, b1.16b; \
rev32 b2.16b, b2.16b; \
ext T0.16b, m1.16b, m1.16b, #8; \
ext T2.16b, m3.16b, m3.16b, #8; \
ext T4.16b, m5.16b, m5.16b, #8; \
sm4e b0.4s, v24.4s; \
sm4e b1.4s, v24.4s; \
sm4e b2.4s, v24.4s; \
pmull r0.1q, m0.1d, m1.1d; \
pmull r2.1q, m2.1d, m3.1d; \
pmull r4.1q, m4.1d, m5.1d; \
sm4e b0.4s, v25.4s; \
sm4e b1.4s, v25.4s; \
sm4e b2.4s, v25.4s; \
pmull T1.1q, m0.1d, T0.1d; \
pmull T3.1q, m2.1d, T2.1d; \
pmull T5.1q, m4.1d, T4.1d; \
sm4e b0.4s, v26.4s; \
sm4e b1.4s, v26.4s; \
sm4e b2.4s, v26.4s; \
pmull2 T0.1q, m0.2d, T0.2d; \
pmull2 T2.1q, m2.2d, T2.2d; \
pmull2 T4.1q, m4.2d, T4.2d; \
sm4e b0.4s, v27.4s; \
sm4e b1.4s, v27.4s; \
sm4e b2.4s, v27.4s; \
pmull2 r1.1q, m0.2d, m1.2d; \
pmull2 r3.1q, m2.2d, m3.2d; \
pmull2 r5.1q, m4.2d, m5.2d; \
sm4e b0.4s, v28.4s; \
sm4e b1.4s, v28.4s; \
sm4e b2.4s, v28.4s; \
eor T0.16b, T0.16b, T1.16b; \
eor T2.16b, T2.16b, T3.16b; \
eor T4.16b, T4.16b, T5.16b; \
sm4e b0.4s, v29.4s; \
sm4e b1.4s, v29.4s; \
sm4e b2.4s, v29.4s; \
ext T1.16b, RZERO.16b, T0.16b, #8; \
ext T3.16b, RZERO.16b, T2.16b, #8; \
ext T5.16b, RZERO.16b, T4.16b, #8; \
sm4e b0.4s, v30.4s; \
sm4e b1.4s, v30.4s; \
sm4e b2.4s, v30.4s; \
ext T0.16b, T0.16b, RZERO.16b, #8; \
ext T2.16b, T2.16b, RZERO.16b, #8; \
ext T4.16b, T4.16b, RZERO.16b, #8; \
sm4e b0.4s, v31.4s; \
sm4e b1.4s, v31.4s; \
sm4e b2.4s, v31.4s; \
eor r0.16b, r0.16b, T1.16b; \
eor r2.16b, r2.16b, T3.16b; \
eor r4.16b, r4.16b, T5.16b; \
rev64 b0.4s, b0.4s; \
rev64 b1.4s, b1.4s; \
rev64 b2.4s, b2.4s; \
eor r1.16b, r1.16b, T0.16b; \
eor r3.16b, r3.16b, T2.16b; \
eor r5.16b, r5.16b, T4.16b; \
ext b0.16b, b0.16b, b0.16b, #8; \
ext b1.16b, b1.16b, b1.16b, #8; \
ext b2.16b, b2.16b, b2.16b, #8; \
eor r0.16b, r0.16b, r2.16b; \
eor r1.16b, r1.16b, r3.16b; \
rev32 b0.16b, b0.16b; \
rev32 b1.16b, b1.16b; \
rev32 b2.16b, b2.16b; \
eor r0.16b, r0.16b, r4.16b; \
eor r1.16b, r1.16b, r5.16b;
#define inc32_le128(vctr) \
mov vctr.d[1], x9; \
add w6, w9, #1; \
mov vctr.d[0], x8; \
bfi x9, x6, #0, #32; \
rev64 vctr.16b, vctr.16b;
#define GTAG_HASH_LENGTHS(vctr0, vlen) \
ld1 {vlen.16b}, [x7]; \
/* construct CTR0 */ \
/* the lower 32-bits of initial IV is always be32(1) */ \
mov x6, #0x1; \
bfi x9, x6, #0, #32; \
mov vctr0.d[0], x8; \
mov vctr0.d[1], x9; \
rbit vlen.16b, vlen.16b; \
rev64 vctr0.16b, vctr0.16b; \
/* authtag = GCTR(CTR0, GHASH) */ \
eor RHASH.16b, RHASH.16b, vlen.16b; \
SM4_CRYPT_PMUL_128x128_BLK(vctr0, RR0, RR1, RHASH, RH1, \
RTMP0, RTMP1); \
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP2, RTMP3); \
rbit RHASH.16b, RHASH.16b; \
eor RHASH.16b, RHASH.16b, vctr0.16b;
/* Register macros for encrypt and ghash */
/* can be the same as input v0-v3 */
#define RR1 v0
#define RR3 v1
#define RR5 v2
#define RR7 v3
#define RR0 v4
#define RR2 v5
#define RR4 v6
#define RR6 v7
#define RTMP0 v8
#define RTMP1 v9
#define RTMP2 v10
#define RTMP3 v11
#define RTMP4 v12
#define RTMP5 v13
#define RTMP6 v14
#define RTMP7 v15
#define RH1 v16
#define RH2 v17
#define RH3 v18
#define RH4 v19
.align 3
SYM_FUNC_START(sm4_ce_pmull_ghash_setup)
/* input:
* x0: round key array, CTX
* x1: ghash table
*/
SM4_PREPARE(x0)
adr_l x2, .Lghash_rconst
ld1r {RRCONST.2d}, [x2]
eor RZERO.16b, RZERO.16b, RZERO.16b
/* H = E(K, 0^128) */
rev32 v0.16b, RZERO.16b
SM4_CRYPT_BLK_BE(v0)
/* H ^ 1 */
rbit RH1.16b, v0.16b
/* H ^ 2 */
PMUL_128x128(RR0, RR1, RH1, RH1, RTMP0, RTMP1)
REDUCTION(RH2, RR0, RR1, RRCONST, RTMP2, RTMP3)
/* H ^ 3 */
PMUL_128x128(RR0, RR1, RH2, RH1, RTMP0, RTMP1)
REDUCTION(RH3, RR0, RR1, RRCONST, RTMP2, RTMP3)
/* H ^ 4 */
PMUL_128x128(RR0, RR1, RH2, RH2, RTMP0, RTMP1)
REDUCTION(RH4, RR0, RR1, RRCONST, RTMP2, RTMP3)
st1 {RH1.16b-RH4.16b}, [x1]
ret
SYM_FUNC_END(sm4_ce_pmull_ghash_setup)
.align 3
SYM_FUNC_START(pmull_ghash_update)
/* input:
* x0: ghash table
* x1: ghash result
* x2: src
* w3: nblocks
*/
ld1 {RH1.16b-RH4.16b}, [x0]
ld1 {RHASH.16b}, [x1]
rbit RHASH.16b, RHASH.16b
adr_l x4, .Lghash_rconst
ld1r {RRCONST.2d}, [x4]
eor RZERO.16b, RZERO.16b, RZERO.16b
.Lghash_loop_4x:
cmp w3, #4
blt .Lghash_loop_1x
sub w3, w3, #4
ld1 {v0.16b-v3.16b}, [x2], #64
rbit v0.16b, v0.16b
rbit v1.16b, v1.16b
rbit v2.16b, v2.16b
rbit v3.16b, v3.16b
/*
* (in0 ^ HASH) * H^4 => rr0:rr1
* (in1) * H^3 => rr2:rr3
* (in2) * H^2 => rr4:rr5
* (in3) * H^1 => rr6:rr7
*/
eor RHASH.16b, RHASH.16b, v0.16b
PMUL_128x128_4x(RR0, RR1, RHASH, RH4, RTMP0, RTMP1,
RR2, RR3, v1, RH3, RTMP2, RTMP3,
RR4, RR5, v2, RH2, RTMP4, RTMP5,
RR6, RR7, v3, RH1, RTMP6, RTMP7)
eor RR0.16b, RR0.16b, RR2.16b
eor RR1.16b, RR1.16b, RR3.16b
eor RR0.16b, RR0.16b, RR4.16b
eor RR1.16b, RR1.16b, RR5.16b
eor RR0.16b, RR0.16b, RR6.16b
eor RR1.16b, RR1.16b, RR7.16b
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP0, RTMP1)
cbz w3, .Lghash_end
b .Lghash_loop_4x
.Lghash_loop_1x:
sub w3, w3, #1
ld1 {v0.16b}, [x2], #16
rbit v0.16b, v0.16b
eor RHASH.16b, RHASH.16b, v0.16b
PMUL_128x128(RR0, RR1, RHASH, RH1, RTMP0, RTMP1)
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP2, RTMP3)
cbnz w3, .Lghash_loop_1x
.Lghash_end:
rbit RHASH.16b, RHASH.16b
st1 {RHASH.2d}, [x1]
ret
SYM_FUNC_END(pmull_ghash_update)
.align 3
SYM_TYPED_FUNC_START(sm4_ce_pmull_gcm_enc)
/* input:
* x0: round key array, CTX
* x1: dst
* x2: src
* x3: ctr (big endian, 128 bit)
* w4: nbytes
* x5: ghash result
* x6: ghash table
* x7: lengths (only for last block)
*/
SM4_PREPARE(x0)
ldp x8, x9, [x3]
rev x8, x8
rev x9, x9
ld1 {RH1.16b-RH4.16b}, [x6]
ld1 {RHASH.16b}, [x5]
rbit RHASH.16b, RHASH.16b
adr_l x6, .Lghash_rconst
ld1r {RRCONST.2d}, [x6]
eor RZERO.16b, RZERO.16b, RZERO.16b
cbz w4, .Lgcm_enc_hash_len
.Lgcm_enc_loop_4x:
cmp w4, #(4 * 16)
blt .Lgcm_enc_loop_1x
sub w4, w4, #(4 * 16)
/* construct CTRs */
inc32_le128(v0) /* +0 */
inc32_le128(v1) /* +1 */
inc32_le128(v2) /* +2 */
inc32_le128(v3) /* +3 */
ld1 {RTMP0.16b-RTMP3.16b}, [x2], #64
SM4_CRYPT_BLK4(v0, v1, v2, v3)
eor v0.16b, v0.16b, RTMP0.16b
eor v1.16b, v1.16b, RTMP1.16b
eor v2.16b, v2.16b, RTMP2.16b
eor v3.16b, v3.16b, RTMP3.16b
st1 {v0.16b-v3.16b}, [x1], #64
/* ghash update */
rbit v0.16b, v0.16b
rbit v1.16b, v1.16b
rbit v2.16b, v2.16b
rbit v3.16b, v3.16b
/*
* (in0 ^ HASH) * H^4 => rr0:rr1
* (in1) * H^3 => rr2:rr3
* (in2) * H^2 => rr4:rr5
* (in3) * H^1 => rr6:rr7
*/
eor RHASH.16b, RHASH.16b, v0.16b
PMUL_128x128_4x(RR0, RR1, RHASH, RH4, RTMP0, RTMP1,
RR2, RR3, v1, RH3, RTMP2, RTMP3,
RR4, RR5, v2, RH2, RTMP4, RTMP5,
RR6, RR7, v3, RH1, RTMP6, RTMP7)
eor RR0.16b, RR0.16b, RR2.16b
eor RR1.16b, RR1.16b, RR3.16b
eor RR0.16b, RR0.16b, RR4.16b
eor RR1.16b, RR1.16b, RR5.16b
eor RR0.16b, RR0.16b, RR6.16b
eor RR1.16b, RR1.16b, RR7.16b
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP0, RTMP1)
cbz w4, .Lgcm_enc_hash_len
b .Lgcm_enc_loop_4x
.Lgcm_enc_loop_1x:
cmp w4, #16
blt .Lgcm_enc_tail
sub w4, w4, #16
/* construct CTRs */
inc32_le128(v0)
ld1 {RTMP0.16b}, [x2], #16
SM4_CRYPT_BLK(v0)
eor v0.16b, v0.16b, RTMP0.16b
st1 {v0.16b}, [x1], #16
/* ghash update */
rbit v0.16b, v0.16b
eor RHASH.16b, RHASH.16b, v0.16b
PMUL_128x128(RR0, RR1, RHASH, RH1, RTMP0, RTMP1)
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP2, RTMP3)
cbz w4, .Lgcm_enc_hash_len
b .Lgcm_enc_loop_1x
.Lgcm_enc_tail:
/* construct CTRs */
inc32_le128(v0)
SM4_CRYPT_BLK(v0)
/* load permute table */
adr_l x0, .Lcts_permute_table
add x0, x0, #32
sub x0, x0, w4, uxtw
ld1 {v3.16b}, [x0]
.Lgcm_enc_tail_loop:
/* do encrypt */
ldrb w0, [x2], #1 /* get 1 byte from input */
umov w6, v0.b[0] /* get top crypted byte */
eor w6, w6, w0 /* w6 = CTR ^ input */
strb w6, [x1], #1 /* store out byte */
/* shift right out one byte */
ext v0.16b, v0.16b, v0.16b, #1
/* the last ciphertext is placed in high bytes */
ins v0.b[15], w6
subs w4, w4, #1
bne .Lgcm_enc_tail_loop
/* padding last block with zeros */
tbl v0.16b, {v0.16b}, v3.16b
/* ghash update */
rbit v0.16b, v0.16b
eor RHASH.16b, RHASH.16b, v0.16b
PMUL_128x128(RR0, RR1, RHASH, RH1, RTMP0, RTMP1)
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP2, RTMP3)
.Lgcm_enc_hash_len:
cbz x7, .Lgcm_enc_end
GTAG_HASH_LENGTHS(v1, v3)
b .Lgcm_enc_ret
.Lgcm_enc_end:
/* store new CTR */
rev x8, x8
rev x9, x9
stp x8, x9, [x3]
rbit RHASH.16b, RHASH.16b
.Lgcm_enc_ret:
/* store new MAC */
st1 {RHASH.2d}, [x5]
ret
SYM_FUNC_END(sm4_ce_pmull_gcm_enc)
#undef RR1
#undef RR3
#undef RR5
#undef RR7
#undef RR0
#undef RR2
#undef RR4
#undef RR6
#undef RTMP0
#undef RTMP1
#undef RTMP2
#undef RTMP3
#undef RTMP4
#undef RTMP5
#undef RTMP6
#undef RTMP7
#undef RH1
#undef RH2
#undef RH3
#undef RH4
/* Register macros for decrypt */
/* v0-v2 for building CTRs, v3-v5 for saving inputs */
#define RR1 v6
#define RR3 v7
#define RR5 v8
#define RR0 v9
#define RR2 v10
#define RR4 v11
#define RTMP0 v12
#define RTMP1 v13
#define RTMP2 v14
#define RTMP3 v15
#define RTMP4 v16
#define RTMP5 v17
#define RH1 v18
#define RH2 v19
#define RH3 v20
.align 3
SYM_TYPED_FUNC_START(sm4_ce_pmull_gcm_dec)
/* input:
* x0: round key array, CTX
* x1: dst
* x2: src
* x3: ctr (big endian, 128 bit)
* w4: nbytes
* x5: ghash result
* x6: ghash table
* x7: lengths (only for last block)
*/
SM4_PREPARE(x0)
ldp x8, x9, [x3]
rev x8, x8
rev x9, x9
ld1 {RH1.16b-RH3.16b}, [x6]
ld1 {RHASH.16b}, [x5]
rbit RHASH.16b, RHASH.16b
adr_l x6, .Lghash_rconst
ld1r {RRCONST.2d}, [x6]
eor RZERO.16b, RZERO.16b, RZERO.16b
cbz w4, .Lgcm_dec_hash_len
.Lgcm_dec_loop_3x:
cmp w4, #(3 * 16)
blt .Lgcm_dec_loop_1x
sub w4, w4, #(3 * 16)
ld1 {v3.16b-v5.16b}, [x2], #(3 * 16)
/* construct CTRs */
inc32_le128(v0) /* +0 */
rbit v6.16b, v3.16b
inc32_le128(v1) /* +1 */
rbit v7.16b, v4.16b
inc32_le128(v2) /* +2 */
rbit v8.16b, v5.16b
eor RHASH.16b, RHASH.16b, v6.16b
/* decrypt & ghash update */
SM4_CRYPT_PMUL_128x128_BLK3(v0, v1, v2,
RR0, RR1, RHASH, RH3, RTMP0, RTMP1,
RR2, RR3, v7, RH2, RTMP2, RTMP3,
RR4, RR5, v8, RH1, RTMP4, RTMP5)
eor v0.16b, v0.16b, v3.16b
eor v1.16b, v1.16b, v4.16b
eor v2.16b, v2.16b, v5.16b
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP0, RTMP1)
st1 {v0.16b-v2.16b}, [x1], #(3 * 16)
cbz w4, .Lgcm_dec_hash_len
b .Lgcm_dec_loop_3x
.Lgcm_dec_loop_1x:
cmp w4, #16
blt .Lgcm_dec_tail
sub w4, w4, #16
ld1 {v3.16b}, [x2], #16
/* construct CTRs */
inc32_le128(v0)
rbit v6.16b, v3.16b
eor RHASH.16b, RHASH.16b, v6.16b
SM4_CRYPT_PMUL_128x128_BLK(v0, RR0, RR1, RHASH, RH1, RTMP0, RTMP1)
eor v0.16b, v0.16b, v3.16b
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP2, RTMP3)
st1 {v0.16b}, [x1], #16
cbz w4, .Lgcm_dec_hash_len
b .Lgcm_dec_loop_1x
.Lgcm_dec_tail:
/* construct CTRs */
inc32_le128(v0)
SM4_CRYPT_BLK(v0)
/* load permute table */
adr_l x0, .Lcts_permute_table
add x0, x0, #32
sub x0, x0, w4, uxtw
ld1 {v3.16b}, [x0]
.Lgcm_dec_tail_loop:
/* do decrypt */
ldrb w0, [x2], #1 /* get 1 byte from input */
umov w6, v0.b[0] /* get top crypted byte */
eor w6, w6, w0 /* w6 = CTR ^ input */
strb w6, [x1], #1 /* store out byte */
/* shift right out one byte */
ext v0.16b, v0.16b, v0.16b, #1
/* the last ciphertext is placed in high bytes */
ins v0.b[15], w0
subs w4, w4, #1
bne .Lgcm_dec_tail_loop
/* padding last block with zeros */
tbl v0.16b, {v0.16b}, v3.16b
/* ghash update */
rbit v0.16b, v0.16b
eor RHASH.16b, RHASH.16b, v0.16b
PMUL_128x128(RR0, RR1, RHASH, RH1, RTMP0, RTMP1)
REDUCTION(RHASH, RR0, RR1, RRCONST, RTMP2, RTMP3)
.Lgcm_dec_hash_len:
cbz x7, .Lgcm_dec_end
GTAG_HASH_LENGTHS(v1, v3)
b .Lgcm_dec_ret
.Lgcm_dec_end:
/* store new CTR */
rev x8, x8
rev x9, x9
stp x8, x9, [x3]
rbit RHASH.16b, RHASH.16b
.Lgcm_dec_ret:
/* store new MAC */
st1 {RHASH.2d}, [x5]
ret
SYM_FUNC_END(sm4_ce_pmull_gcm_dec)
.section ".rodata", "a"
.align 4
.Lcts_permute_table:
.byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
.byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
.byte 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7
.byte 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf
.byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
.byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
.Lghash_rconst:
.quad 0x87