linux/arch/arm64/crypto/aes-cipher-core.S
Ard Biesheuvel 96a74f7bdc crypto: arm64/aes-cipher - move S-box to .rodata section
Move the AES inverse S-box to the .rodata section where it is safe from
abuse by speculation.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-18 23:00:30 +11:00

174 lines
5.3 KiB
ArmAsm

/*
* Scalar AES core transform
*
* Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/cache.h>
.text
rk .req x0
out .req x1
in .req x2
rounds .req x3
tt .req x2
.macro __pair1, sz, op, reg0, reg1, in0, in1e, in1d, shift
.ifc \op\shift, b0
ubfiz \reg0, \in0, #2, #8
ubfiz \reg1, \in1e, #2, #8
.else
ubfx \reg0, \in0, #\shift, #8
ubfx \reg1, \in1e, #\shift, #8
.endif
/*
* AArch64 cannot do byte size indexed loads from a table containing
* 32-bit quantities, i.e., 'ldrb w12, [tt, w12, uxtw #2]' is not a
* valid instruction. So perform the shift explicitly first for the
* high bytes (the low byte is shifted implicitly by using ubfiz rather
* than ubfx above)
*/
.ifnc \op, b
ldr \reg0, [tt, \reg0, uxtw #2]
ldr \reg1, [tt, \reg1, uxtw #2]
.else
.if \shift > 0
lsl \reg0, \reg0, #2
lsl \reg1, \reg1, #2
.endif
ldrb \reg0, [tt, \reg0, uxtw]
ldrb \reg1, [tt, \reg1, uxtw]
.endif
.endm
.macro __pair0, sz, op, reg0, reg1, in0, in1e, in1d, shift
ubfx \reg0, \in0, #\shift, #8
ubfx \reg1, \in1d, #\shift, #8
ldr\op \reg0, [tt, \reg0, uxtw #\sz]
ldr\op \reg1, [tt, \reg1, uxtw #\sz]
.endm
.macro __hround, out0, out1, in0, in1, in2, in3, t0, t1, enc, sz, op
ldp \out0, \out1, [rk], #8
__pair\enc \sz, \op, w12, w13, \in0, \in1, \in3, 0
__pair\enc \sz, \op, w14, w15, \in1, \in2, \in0, 8
__pair\enc \sz, \op, w16, w17, \in2, \in3, \in1, 16
__pair\enc \sz, \op, \t0, \t1, \in3, \in0, \in2, 24
eor \out0, \out0, w12
eor \out1, \out1, w13
eor \out0, \out0, w14, ror #24
eor \out1, \out1, w15, ror #24
eor \out0, \out0, w16, ror #16
eor \out1, \out1, w17, ror #16
eor \out0, \out0, \t0, ror #8
eor \out1, \out1, \t1, ror #8
.endm
.macro fround, out0, out1, out2, out3, in0, in1, in2, in3, sz=2, op
__hround \out0, \out1, \in0, \in1, \in2, \in3, \out2, \out3, 1, \sz, \op
__hround \out2, \out3, \in2, \in3, \in0, \in1, \in1, \in2, 1, \sz, \op
.endm
.macro iround, out0, out1, out2, out3, in0, in1, in2, in3, sz=2, op
__hround \out0, \out1, \in0, \in3, \in2, \in1, \out2, \out3, 0, \sz, \op
__hround \out2, \out3, \in2, \in1, \in0, \in3, \in1, \in0, 0, \sz, \op
.endm
.macro do_crypt, round, ttab, ltab, bsz
ldp w4, w5, [in]
ldp w6, w7, [in, #8]
ldp w8, w9, [rk], #16
ldp w10, w11, [rk, #-8]
CPU_BE( rev w4, w4 )
CPU_BE( rev w5, w5 )
CPU_BE( rev w6, w6 )
CPU_BE( rev w7, w7 )
eor w4, w4, w8
eor w5, w5, w9
eor w6, w6, w10
eor w7, w7, w11
adr_l tt, \ttab
tbnz rounds, #1, 1f
0: \round w8, w9, w10, w11, w4, w5, w6, w7
\round w4, w5, w6, w7, w8, w9, w10, w11
1: subs rounds, rounds, #4
\round w8, w9, w10, w11, w4, w5, w6, w7
b.ls 3f
2: \round w4, w5, w6, w7, w8, w9, w10, w11
b 0b
3: adr_l tt, \ltab
\round w4, w5, w6, w7, w8, w9, w10, w11, \bsz, b
CPU_BE( rev w4, w4 )
CPU_BE( rev w5, w5 )
CPU_BE( rev w6, w6 )
CPU_BE( rev w7, w7 )
stp w4, w5, [out]
stp w6, w7, [out, #8]
ret
.endm
ENTRY(__aes_arm64_encrypt)
do_crypt fround, crypto_ft_tab, crypto_ft_tab + 1, 2
ENDPROC(__aes_arm64_encrypt)
.align 5
ENTRY(__aes_arm64_decrypt)
do_crypt iround, crypto_it_tab, __aes_arm64_inverse_sbox, 0
ENDPROC(__aes_arm64_decrypt)
.section ".rodata", "a"
.align L1_CACHE_SHIFT
.type __aes_arm64_inverse_sbox, %object
__aes_arm64_inverse_sbox:
.byte 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38
.byte 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb
.byte 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87
.byte 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb
.byte 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d
.byte 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e
.byte 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2
.byte 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25
.byte 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16
.byte 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92
.byte 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda
.byte 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84
.byte 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a
.byte 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06
.byte 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02
.byte 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b
.byte 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea
.byte 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73
.byte 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85
.byte 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e
.byte 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89
.byte 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b
.byte 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20
.byte 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4
.byte 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31
.byte 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f
.byte 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d
.byte 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef
.byte 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0
.byte 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61
.byte 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26
.byte 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
.size __aes_arm64_inverse_sbox, . - __aes_arm64_inverse_sbox