mbedtls/library/armv8ce_aes.c
Hanno Becker 140fd9c0ba Fix coding style in library/armv8ce_aes.c
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
2020-09-07 12:02:41 +01:00

143 lines
4.6 KiB
C

/*
* ARMv8 Cryptography Extensions -- Optimized code for AES and GCM
*
* Copyright (C) 2006-2017, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_ARMV8CE_AES_C)
#include <arm_neon.h>
#include "mbedtls/armv8ce_aes.h"
#ifndef asm
#define asm __asm
#endif
/*
* [Armv8 Cryptography Extensions] AES-ECB block en(de)cryption
*/
#if defined(MBEDTLS_AES_C)
int mbedtls_armv8ce_aes_crypt_ecb( mbedtls_aes_context *ctx,
int mode,
const unsigned char input[16],
unsigned char output[16] )
{
unsigned int i;
const uint8_t *rk;
uint8x16_t x, k;
x = vld1q_u8( input ); /* input block */
rk = (const uint8_t *) ctx->rk; /* round keys */
if( mode == MBEDTLS_AES_ENCRYPT )
{
for( i = ctx->nr - 1; i != 0; i-- ) /* encryption loop */
{
k = vld1q_u8( rk );
rk += 16;
x = vaeseq_u8( x, k );
x = vaesmcq_u8( x );
}
k = vld1q_u8( rk );
rk += 16;
x = vaeseq_u8( x, k );
}
else
{
for( i = ctx->nr - 1; i != 0 ; i-- ) /* decryption loop */
{
k = vld1q_u8( rk );
rk += 16;
x = vaesdq_u8( x, k );
x = vaesimcq_u8( x );
}
k = vld1q_u8( rk );
rk += 16;
x = vaesdq_u8( x, k );
}
k = vld1q_u8( rk ); /* final key just XORed */
x = veorq_u8( x, k );
vst1q_u8( output, x ); /* write out */
return ( 0 );
}
#endif /* MBEDTLS_AES_C */
/*
* [Armv8 Cryptography Extensions] Multiply in GF(2^128) for GCM
*/
#if defined(MBEDTLS_GCM_C)
void mbedtls_armv8ce_gcm_mult( unsigned char c[16],
const unsigned char a[16],
const unsigned char b[16] )
{
/* GCM's GF(2^128) polynomial basis is x^128 + x^7 + x^2 + x + 1 */
const uint64x2_t base = { 0, 0x86 }; /* note missing LS bit */
register uint8x16_t vc asm( "v0" ); /* named registers */
register uint8x16_t va asm( "v1" ); /* (to avoid conflict) */
register uint8x16_t vb asm( "v2" );
register uint64x2_t vp asm( "v3" );
va = vld1q_u8( a ); /* load inputs */
vb = vld1q_u8( b );
vp = base;
asm (
"rbit %1.16b, %1.16b \n\t" /* reverse bit order */
"rbit %2.16b, %2.16b \n\t"
"pmull2 %0.1q, %1.2d, %2.2d \n\t" /* v0 = a.hi * b.hi */
"pmull2 v4.1q, %0.2d, %3.2d \n\t" /* mul v0 by x^64, reduce */
"ext %0.16b, %0.16b, %0.16b, #8 \n\t"
"eor %0.16b, %0.16b, v4.16b \n\t"
"ext v5.16b, %2.16b, %2.16b, #8 \n\t" /* (swap hi and lo in b) */
"pmull v4.1q, %1.1d, v5.1d \n\t" /* v0 ^= a.lo * b.hi */
"eor %0.16b, %0.16b, v4.16b \n\t"
"pmull2 v4.1q, %1.2d, v5.2d \n\t" /* v0 ^= a.hi * b.lo */
"eor %0.16b, %0.16b, v4.16b \n\t"
"pmull2 v4.1q, %0.2d, %3.2d \n\t" /* mul v0 by x^64, reduce */
"ext %0.16b, %0.16b, %0.16b, #8 \n\t"
"eor %0.16b, %0.16b, v4.16b \n\t"
"pmull v4.1q, %1.1d, %2.1d \n\t" /* v0 ^= a.lo * b.lo */
"eor %0.16b, %0.16b, v4.16b \n\t"
"rbit %0.16b, %0.16b \n\t" /* reverse bits for output */
: "=w" (vc) /* q0: output */
: "w" (va), "w" (vb), "w" (vp) /* q1, q2: input */
: "v4", "v5" /* q4, q5: clobbered */
);
vst1q_u8( c, vc ); /* write out */
}
#endif /* MBEDTLS_GCM_C */
#endif /* MBEDTLS_ARMV8CE_AES_C */