linux/arch/arm/crypto/aes-ce-core.S
Ard Biesheuvel f3456b9fd2 crypto: arm/aes-ce - work around Cortex-A57/A72 silion errata
ARM Cortex-A57 and Cortex-A72 cores running in 32-bit mode are affected
by silicon errata #1742098 and #1655431, respectively, where the second
instruction of a AES instruction pair may execute twice if an interrupt
is taken right after the first instruction consumes an input register of
which a single 32-bit lane has been updated the last time it was modified.

This is not such a rare occurrence as it may seem: in counter mode, only
the least significant 32-bit word is incremented in the absence of a
carry, which makes our counter mode implementation susceptible to these
errata.

So let's shuffle the counter assignments around a bit so that the most
recent updates when the AES instruction pair executes are 128-bit wide.

[0] ARM-EPM-049219 v23 Cortex-A57 MPCore Software Developers Errata Notice
[1] ARM-EPM-012079 v11.0 Cortex-A72 MPCore Software Developers Errata Notice

Cc: <stable@vger.kernel.org> # v5.4+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-12-04 18:13:14 +11:00

714 lines
15 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* aes-ce-core.S - AES in CBC/CTR/XTS mode using ARMv8 Crypto Extensions
*
* Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
.text
.arch armv8-a
.fpu crypto-neon-fp-armv8
.align 3
.macro enc_round, state, key
aese.8 \state, \key
aesmc.8 \state, \state
.endm
.macro dec_round, state, key
aesd.8 \state, \key
aesimc.8 \state, \state
.endm
.macro enc_dround, key1, key2
enc_round q0, \key1
enc_round q0, \key2
.endm
.macro dec_dround, key1, key2
dec_round q0, \key1
dec_round q0, \key2
.endm
.macro enc_fround, key1, key2, key3
enc_round q0, \key1
aese.8 q0, \key2
veor q0, q0, \key3
.endm
.macro dec_fround, key1, key2, key3
dec_round q0, \key1
aesd.8 q0, \key2
veor q0, q0, \key3
.endm
.macro enc_dround_4x, key1, key2
enc_round q0, \key1
enc_round q1, \key1
enc_round q2, \key1
enc_round q3, \key1
enc_round q0, \key2
enc_round q1, \key2
enc_round q2, \key2
enc_round q3, \key2
.endm
.macro dec_dround_4x, key1, key2
dec_round q0, \key1
dec_round q1, \key1
dec_round q2, \key1
dec_round q3, \key1
dec_round q0, \key2
dec_round q1, \key2
dec_round q2, \key2
dec_round q3, \key2
.endm
.macro enc_fround_4x, key1, key2, key3
enc_round q0, \key1
enc_round q1, \key1
enc_round q2, \key1
enc_round q3, \key1
aese.8 q0, \key2
aese.8 q1, \key2
aese.8 q2, \key2
aese.8 q3, \key2
veor q0, q0, \key3
veor q1, q1, \key3
veor q2, q2, \key3
veor q3, q3, \key3
.endm
.macro dec_fround_4x, key1, key2, key3
dec_round q0, \key1
dec_round q1, \key1
dec_round q2, \key1
dec_round q3, \key1
aesd.8 q0, \key2
aesd.8 q1, \key2
aesd.8 q2, \key2
aesd.8 q3, \key2
veor q0, q0, \key3
veor q1, q1, \key3
veor q2, q2, \key3
veor q3, q3, \key3
.endm
.macro do_block, dround, fround
cmp r3, #12 @ which key size?
vld1.32 {q10-q11}, [ip]!
\dround q8, q9
vld1.32 {q12-q13}, [ip]!
\dround q10, q11
vld1.32 {q10-q11}, [ip]!
\dround q12, q13
vld1.32 {q12-q13}, [ip]!
\dround q10, q11
blo 0f @ AES-128: 10 rounds
vld1.32 {q10-q11}, [ip]!
\dround q12, q13
beq 1f @ AES-192: 12 rounds
vld1.32 {q12-q13}, [ip]
\dround q10, q11
0: \fround q12, q13, q14
bx lr
1: \fround q10, q11, q14
bx lr
.endm
/*
* Internal, non-AAPCS compliant functions that implement the core AES
* transforms. These should preserve all registers except q0 - q2 and ip
* Arguments:
* q0 : first in/output block
* q1 : second in/output block (_4x version only)
* q2 : third in/output block (_4x version only)
* q3 : fourth in/output block (_4x version only)
* q8 : first round key
* q9 : secound round key
* q14 : final round key
* r2 : address of round key array
* r3 : number of rounds
*/
.align 6
aes_encrypt:
add ip, r2, #32 @ 3rd round key
.Laes_encrypt_tweak:
do_block enc_dround, enc_fround
ENDPROC(aes_encrypt)
.align 6
aes_decrypt:
add ip, r2, #32 @ 3rd round key
do_block dec_dround, dec_fround
ENDPROC(aes_decrypt)
.align 6
aes_encrypt_4x:
add ip, r2, #32 @ 3rd round key
do_block enc_dround_4x, enc_fround_4x
ENDPROC(aes_encrypt_4x)
.align 6
aes_decrypt_4x:
add ip, r2, #32 @ 3rd round key
do_block dec_dround_4x, dec_fround_4x
ENDPROC(aes_decrypt_4x)
.macro prepare_key, rk, rounds
add ip, \rk, \rounds, lsl #4
vld1.32 {q8-q9}, [\rk] @ load first 2 round keys
vld1.32 {q14}, [ip] @ load last round key
.endm
/*
* aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[], int rounds,
* int blocks)
* aes_ecb_decrypt(u8 out[], u8 const in[], u32 const rk[], int rounds,
* int blocks)
*/
ENTRY(ce_aes_ecb_encrypt)
push {r4, lr}
ldr r4, [sp, #8]
prepare_key r2, r3
.Lecbencloop4x:
subs r4, r4, #4
bmi .Lecbenc1x
vld1.8 {q0-q1}, [r1]!
vld1.8 {q2-q3}, [r1]!
bl aes_encrypt_4x
vst1.8 {q0-q1}, [r0]!
vst1.8 {q2-q3}, [r0]!
b .Lecbencloop4x
.Lecbenc1x:
adds r4, r4, #4
beq .Lecbencout
.Lecbencloop:
vld1.8 {q0}, [r1]!
bl aes_encrypt
vst1.8 {q0}, [r0]!
subs r4, r4, #1
bne .Lecbencloop
.Lecbencout:
pop {r4, pc}
ENDPROC(ce_aes_ecb_encrypt)
ENTRY(ce_aes_ecb_decrypt)
push {r4, lr}
ldr r4, [sp, #8]
prepare_key r2, r3
.Lecbdecloop4x:
subs r4, r4, #4
bmi .Lecbdec1x
vld1.8 {q0-q1}, [r1]!
vld1.8 {q2-q3}, [r1]!
bl aes_decrypt_4x
vst1.8 {q0-q1}, [r0]!
vst1.8 {q2-q3}, [r0]!
b .Lecbdecloop4x
.Lecbdec1x:
adds r4, r4, #4
beq .Lecbdecout
.Lecbdecloop:
vld1.8 {q0}, [r1]!
bl aes_decrypt
vst1.8 {q0}, [r0]!
subs r4, r4, #1
bne .Lecbdecloop
.Lecbdecout:
pop {r4, pc}
ENDPROC(ce_aes_ecb_decrypt)
/*
* aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[], int rounds,
* int blocks, u8 iv[])
* aes_cbc_decrypt(u8 out[], u8 const in[], u32 const rk[], int rounds,
* int blocks, u8 iv[])
*/
ENTRY(ce_aes_cbc_encrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
vld1.8 {q0}, [r5]
prepare_key r2, r3
.Lcbcencloop:
vld1.8 {q1}, [r1]! @ get next pt block
veor q0, q0, q1 @ ..and xor with iv
bl aes_encrypt
vst1.8 {q0}, [r0]!
subs r4, r4, #1
bne .Lcbcencloop
vst1.8 {q0}, [r5]
pop {r4-r6, pc}
ENDPROC(ce_aes_cbc_encrypt)
ENTRY(ce_aes_cbc_decrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
vld1.8 {q15}, [r5] @ keep iv in q15
prepare_key r2, r3
.Lcbcdecloop4x:
subs r4, r4, #4
bmi .Lcbcdec1x
vld1.8 {q0-q1}, [r1]!
vld1.8 {q2-q3}, [r1]!
vmov q4, q0
vmov q5, q1
vmov q6, q2
vmov q7, q3
bl aes_decrypt_4x
veor q0, q0, q15
veor q1, q1, q4
veor q2, q2, q5
veor q3, q3, q6
vmov q15, q7
vst1.8 {q0-q1}, [r0]!
vst1.8 {q2-q3}, [r0]!
b .Lcbcdecloop4x
.Lcbcdec1x:
adds r4, r4, #4
beq .Lcbcdecout
vmov q6, q14 @ preserve last round key
.Lcbcdecloop:
vld1.8 {q0}, [r1]! @ get next ct block
veor q14, q15, q6 @ combine prev ct with last key
vmov q15, q0
bl aes_decrypt
vst1.8 {q0}, [r0]!
subs r4, r4, #1
bne .Lcbcdecloop
.Lcbcdecout:
vst1.8 {q15}, [r5] @ keep iv in q15
pop {r4-r6, pc}
ENDPROC(ce_aes_cbc_decrypt)
/*
* ce_aes_cbc_cts_encrypt(u8 out[], u8 const in[], u32 const rk[],
* int rounds, int bytes, u8 const iv[])
* ce_aes_cbc_cts_decrypt(u8 out[], u8 const in[], u32 const rk[],
* int rounds, int bytes, u8 const iv[])
*/
ENTRY(ce_aes_cbc_cts_encrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
movw ip, :lower16:.Lcts_permute_table
movt ip, :upper16:.Lcts_permute_table
sub r4, r4, #16
add lr, ip, #32
add ip, ip, r4
sub lr, lr, r4
vld1.8 {q5}, [ip]
vld1.8 {q6}, [lr]
add ip, r1, r4
vld1.8 {q0}, [r1] @ overlapping loads
vld1.8 {q3}, [ip]
vld1.8 {q1}, [r5] @ get iv
prepare_key r2, r3
veor q0, q0, q1 @ xor with iv
bl aes_encrypt
vtbl.8 d4, {d0-d1}, d10
vtbl.8 d5, {d0-d1}, d11
vtbl.8 d2, {d6-d7}, d12
vtbl.8 d3, {d6-d7}, d13
veor q0, q0, q1
bl aes_encrypt
add r4, r0, r4
vst1.8 {q2}, [r4] @ overlapping stores
vst1.8 {q0}, [r0]
pop {r4-r6, pc}
ENDPROC(ce_aes_cbc_cts_encrypt)
ENTRY(ce_aes_cbc_cts_decrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
movw ip, :lower16:.Lcts_permute_table
movt ip, :upper16:.Lcts_permute_table
sub r4, r4, #16
add lr, ip, #32
add ip, ip, r4
sub lr, lr, r4
vld1.8 {q5}, [ip]
vld1.8 {q6}, [lr]
add ip, r1, r4
vld1.8 {q0}, [r1] @ overlapping loads
vld1.8 {q1}, [ip]
vld1.8 {q3}, [r5] @ get iv
prepare_key r2, r3
bl aes_decrypt
vtbl.8 d4, {d0-d1}, d10
vtbl.8 d5, {d0-d1}, d11
vtbx.8 d0, {d2-d3}, d12
vtbx.8 d1, {d2-d3}, d13
veor q1, q1, q2
bl aes_decrypt
veor q0, q0, q3 @ xor with iv
add r4, r0, r4
vst1.8 {q1}, [r4] @ overlapping stores
vst1.8 {q0}, [r0]
pop {r4-r6, pc}
ENDPROC(ce_aes_cbc_cts_decrypt)
/*
* aes_ctr_encrypt(u8 out[], u8 const in[], u32 const rk[], int rounds,
* int blocks, u8 ctr[])
*/
ENTRY(ce_aes_ctr_encrypt)
push {r4-r6, lr}
ldrd r4, r5, [sp, #16]
vld1.8 {q7}, [r5] @ load ctr
prepare_key r2, r3
vmov r6, s31 @ keep swabbed ctr in r6
rev r6, r6
cmn r6, r4 @ 32 bit overflow?
bcs .Lctrloop
.Lctrloop4x:
subs r4, r4, #4
bmi .Lctr1x
/*
* NOTE: the sequence below has been carefully tweaked to avoid
* a silicon erratum that exists in Cortex-A57 (#1742098) and
* Cortex-A72 (#1655431) cores, where AESE/AESMC instruction pairs
* may produce an incorrect result if they take their input from a
* register of which a single 32-bit lane has been updated the last
* time it was modified. To work around this, the lanes of registers
* q0-q3 below are not manipulated individually, and the different
* counter values are prepared by successive manipulations of q7.
*/
add ip, r6, #1
vmov q0, q7
rev ip, ip
add lr, r6, #2
vmov s31, ip @ set lane 3 of q1 via q7
add ip, r6, #3
rev lr, lr
vmov q1, q7
vmov s31, lr @ set lane 3 of q2 via q7
rev ip, ip
vmov q2, q7
vmov s31, ip @ set lane 3 of q3 via q7
add r6, r6, #4
vmov q3, q7
vld1.8 {q4-q5}, [r1]!
vld1.8 {q6}, [r1]!
vld1.8 {q15}, [r1]!
bl aes_encrypt_4x
veor q0, q0, q4
veor q1, q1, q5
veor q2, q2, q6
veor q3, q3, q15
rev ip, r6
vst1.8 {q0-q1}, [r0]!
vst1.8 {q2-q3}, [r0]!
vmov s31, ip
b .Lctrloop4x
.Lctr1x:
adds r4, r4, #4
beq .Lctrout
.Lctrloop:
vmov q0, q7
bl aes_encrypt
adds r6, r6, #1 @ increment BE ctr
rev ip, r6
vmov s31, ip
bcs .Lctrcarry
.Lctrcarrydone:
subs r4, r4, #1
bmi .Lctrtailblock @ blocks < 0 means tail block
vld1.8 {q3}, [r1]!
veor q3, q0, q3
vst1.8 {q3}, [r0]!
bne .Lctrloop
.Lctrout:
vst1.8 {q7}, [r5] @ return next CTR value
pop {r4-r6, pc}
.Lctrtailblock:
vst1.8 {q0}, [r0, :64] @ return the key stream
b .Lctrout
.Lctrcarry:
.irp sreg, s30, s29, s28
vmov ip, \sreg @ load next word of ctr
rev ip, ip @ ... to handle the carry
adds ip, ip, #1
rev ip, ip
vmov \sreg, ip
bcc .Lctrcarrydone
.endr
b .Lctrcarrydone
ENDPROC(ce_aes_ctr_encrypt)
/*
* aes_xts_encrypt(u8 out[], u8 const in[], u32 const rk1[], int rounds,
* int bytes, u8 iv[], u32 const rk2[], int first)
* aes_xts_decrypt(u8 out[], u8 const in[], u32 const rk1[], int rounds,
* int bytes, u8 iv[], u32 const rk2[], int first)
*/
.macro next_tweak, out, in, const, tmp
vshr.s64 \tmp, \in, #63
vand \tmp, \tmp, \const
vadd.u64 \out, \in, \in
vext.8 \tmp, \tmp, \tmp, #8
veor \out, \out, \tmp
.endm
ce_aes_xts_init:
vmov.i32 d30, #0x87 @ compose tweak mask vector
vmovl.u32 q15, d30
vshr.u64 d30, d31, #7
ldrd r4, r5, [sp, #16] @ load args
ldr r6, [sp, #28]
vld1.8 {q0}, [r5] @ load iv
teq r6, #1 @ start of a block?
bxne lr
@ Encrypt the IV in q0 with the second AES key. This should only
@ be done at the start of a block.
ldr r6, [sp, #24] @ load AES key 2
prepare_key r6, r3
add ip, r6, #32 @ 3rd round key of key 2
b .Laes_encrypt_tweak @ tail call
ENDPROC(ce_aes_xts_init)
ENTRY(ce_aes_xts_encrypt)
push {r4-r6, lr}
bl ce_aes_xts_init @ run shared prologue
prepare_key r2, r3
vmov q4, q0
teq r6, #0 @ start of a block?
bne .Lxtsenc4x
.Lxtsencloop4x:
next_tweak q4, q4, q15, q10
.Lxtsenc4x:
subs r4, r4, #64
bmi .Lxtsenc1x
vld1.8 {q0-q1}, [r1]! @ get 4 pt blocks
vld1.8 {q2-q3}, [r1]!
next_tweak q5, q4, q15, q10
veor q0, q0, q4
next_tweak q6, q5, q15, q10
veor q1, q1, q5
next_tweak q7, q6, q15, q10
veor q2, q2, q6
veor q3, q3, q7
bl aes_encrypt_4x
veor q0, q0, q4
veor q1, q1, q5
veor q2, q2, q6
veor q3, q3, q7
vst1.8 {q0-q1}, [r0]! @ write 4 ct blocks
vst1.8 {q2-q3}, [r0]!
vmov q4, q7
teq r4, #0
beq .Lxtsencret
b .Lxtsencloop4x
.Lxtsenc1x:
adds r4, r4, #64
beq .Lxtsencout
subs r4, r4, #16
bmi .LxtsencctsNx
.Lxtsencloop:
vld1.8 {q0}, [r1]!
.Lxtsencctsout:
veor q0, q0, q4
bl aes_encrypt
veor q0, q0, q4
teq r4, #0
beq .Lxtsencout
subs r4, r4, #16
next_tweak q4, q4, q15, q6
bmi .Lxtsenccts
vst1.8 {q0}, [r0]!
b .Lxtsencloop
.Lxtsencout:
vst1.8 {q0}, [r0]
.Lxtsencret:
vst1.8 {q4}, [r5]
pop {r4-r6, pc}
.LxtsencctsNx:
vmov q0, q3
sub r0, r0, #16
.Lxtsenccts:
movw ip, :lower16:.Lcts_permute_table
movt ip, :upper16:.Lcts_permute_table
add r1, r1, r4 @ rewind input pointer
add r4, r4, #16 @ # bytes in final block
add lr, ip, #32
add ip, ip, r4
sub lr, lr, r4
add r4, r0, r4 @ output address of final block
vld1.8 {q1}, [r1] @ load final partial block
vld1.8 {q2}, [ip]
vld1.8 {q3}, [lr]
vtbl.8 d4, {d0-d1}, d4
vtbl.8 d5, {d0-d1}, d5
vtbx.8 d0, {d2-d3}, d6
vtbx.8 d1, {d2-d3}, d7
vst1.8 {q2}, [r4] @ overlapping stores
mov r4, #0
b .Lxtsencctsout
ENDPROC(ce_aes_xts_encrypt)
ENTRY(ce_aes_xts_decrypt)
push {r4-r6, lr}
bl ce_aes_xts_init @ run shared prologue
prepare_key r2, r3
vmov q4, q0
/* subtract 16 bytes if we are doing CTS */
tst r4, #0xf
subne r4, r4, #0x10
teq r6, #0 @ start of a block?
bne .Lxtsdec4x
.Lxtsdecloop4x:
next_tweak q4, q4, q15, q10
.Lxtsdec4x:
subs r4, r4, #64
bmi .Lxtsdec1x
vld1.8 {q0-q1}, [r1]! @ get 4 ct blocks
vld1.8 {q2-q3}, [r1]!
next_tweak q5, q4, q15, q10
veor q0, q0, q4
next_tweak q6, q5, q15, q10
veor q1, q1, q5
next_tweak q7, q6, q15, q10
veor q2, q2, q6
veor q3, q3, q7
bl aes_decrypt_4x
veor q0, q0, q4
veor q1, q1, q5
veor q2, q2, q6
veor q3, q3, q7
vst1.8 {q0-q1}, [r0]! @ write 4 pt blocks
vst1.8 {q2-q3}, [r0]!
vmov q4, q7
teq r4, #0
beq .Lxtsdecout
b .Lxtsdecloop4x
.Lxtsdec1x:
adds r4, r4, #64
beq .Lxtsdecout
subs r4, r4, #16
.Lxtsdecloop:
vld1.8 {q0}, [r1]!
bmi .Lxtsdeccts
.Lxtsdecctsout:
veor q0, q0, q4
bl aes_decrypt
veor q0, q0, q4
vst1.8 {q0}, [r0]!
teq r4, #0
beq .Lxtsdecout
subs r4, r4, #16
next_tweak q4, q4, q15, q6
b .Lxtsdecloop
.Lxtsdecout:
vst1.8 {q4}, [r5]
pop {r4-r6, pc}
.Lxtsdeccts:
movw ip, :lower16:.Lcts_permute_table
movt ip, :upper16:.Lcts_permute_table
add r1, r1, r4 @ rewind input pointer
add r4, r4, #16 @ # bytes in final block
add lr, ip, #32
add ip, ip, r4
sub lr, lr, r4
add r4, r0, r4 @ output address of final block
next_tweak q5, q4, q15, q6
vld1.8 {q1}, [r1] @ load final partial block
vld1.8 {q2}, [ip]
vld1.8 {q3}, [lr]
veor q0, q0, q5
bl aes_decrypt
veor q0, q0, q5
vtbl.8 d4, {d0-d1}, d4
vtbl.8 d5, {d0-d1}, d5
vtbx.8 d0, {d2-d3}, d6
vtbx.8 d1, {d2-d3}, d7
vst1.8 {q2}, [r4] @ overlapping stores
mov r4, #0
b .Lxtsdecctsout
ENDPROC(ce_aes_xts_decrypt)
/*
* u32 ce_aes_sub(u32 input) - use the aese instruction to perform the
* AES sbox substitution on each byte in
* 'input'
*/
ENTRY(ce_aes_sub)
vdup.32 q1, r0
veor q0, q0, q0
aese.8 q0, q1
vmov r0, s0
bx lr
ENDPROC(ce_aes_sub)
/*
* void ce_aes_invert(u8 *dst, u8 *src) - perform the Inverse MixColumns
* operation on round key *src
*/
ENTRY(ce_aes_invert)
vld1.32 {q0}, [r1]
aesimc.8 q0, q0
vst1.32 {q0}, [r0]
bx lr
ENDPROC(ce_aes_invert)
.section ".rodata", "a"
.align 6
.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