@@ -2,10 +2,11 @@
/*
* AES-NI + SSE4.1 implementation of AEGIS-128
*
* Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com>
* Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
+ * Copyright 2024 Google LLC
*/
#include <linux/linkage.h>
#include <asm/frame.h>
@@ -26,15 +27,15 @@
.byte 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62
.Laegis128_const_1:
.byte 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1
.byte 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd
-.section .rodata.cst16.aegis128_counter, "aM", @progbits, 16
-.align 16
-.Laegis128_counter:
- .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07
- .byte 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+.section .rodata.cst32.zeropad_mask, "aM", @progbits, 32
+.align 32
+.Lzeropad_mask:
+ .octa 0xffffffffffffffffffffffffffffffff
+ .octa 0
.text
/*
* aegis128_update
@@ -53,136 +54,90 @@
aesenc STATE3, STATE2
aesenc T0, STATE3
.endm
/*
- * __load_partial: internal ABI
- * input:
- * LEN - bytes
- * SRC - src
- * output:
- * MSG - message block
- * changed:
- * T0
- * %r8
- * %r9
+ * Load 1 <= LEN (%ecx) <= 15 bytes from the pointer SRC into the xmm register
+ * MSG and zeroize any remaining bytes. Clobbers %rax, %rcx, and %r8.
*/
-SYM_FUNC_START_LOCAL(__load_partial)
- .set LEN, %ecx
- .set SRC, %rsi
- xor %r9d, %r9d
- pxor MSG, MSG
-
- mov LEN, %r8d
- and $0x1, %r8
- jz .Lld_partial_1
-
- mov LEN, %r8d
- and $0x1E, %r8
- add SRC, %r8
- mov (%r8), %r9b
-
-.Lld_partial_1:
- mov LEN, %r8d
- and $0x2, %r8
- jz .Lld_partial_2
-
- mov LEN, %r8d
- and $0x1C, %r8
- add SRC, %r8
- shl $0x10, %r9
- mov (%r8), %r9w
-
-.Lld_partial_2:
- mov LEN, %r8d
- and $0x4, %r8
- jz .Lld_partial_4
-
- mov LEN, %r8d
- and $0x18, %r8
- add SRC, %r8
- shl $32, %r9
- mov (%r8), %r8d
- xor %r8, %r9
-
-.Lld_partial_4:
- movq %r9, MSG
-
- mov LEN, %r8d
- and $0x8, %r8
- jz .Lld_partial_8
-
- mov LEN, %r8d
- and $0x10, %r8
- add SRC, %r8
- pslldq $8, MSG
- movq (%r8), T0
- pxor T0, MSG
-
-.Lld_partial_8:
- RET
-SYM_FUNC_END(__load_partial)
+.macro load_partial
+ sub $8, %ecx /* LEN - 8 */
+ jle .Lle8\@
+
+ /* Load 9 <= LEN <= 15 bytes: */
+ movq (SRC), MSG /* Load first 8 bytes */
+ mov (SRC, %rcx), %rax /* Load last 8 bytes */
+ neg %ecx
+ shl $3, %ecx
+ shr %cl, %rax /* Discard overlapping bytes */
+ pinsrq $1, %rax, MSG
+ jmp .Ldone\@
+
+.Lle8\@:
+ add $4, %ecx /* LEN - 4 */
+ jl .Llt4\@
+
+ /* Load 4 <= LEN <= 8 bytes: */
+ mov (SRC), %eax /* Load first 4 bytes */
+ mov (SRC, %rcx), %r8d /* Load last 4 bytes */
+ jmp .Lcombine\@
+
+.Llt4\@:
+ /* Load 1 <= LEN <= 3 bytes: */
+ add $2, %ecx /* LEN - 2 */
+ movzbl (SRC), %eax /* Load first byte */
+ jl .Lmovq\@
+ movzwl (SRC, %rcx), %r8d /* Load last 2 bytes */
+.Lcombine\@:
+ shl $3, %ecx
+ shl %cl, %r8
+ or %r8, %rax /* Combine the two parts */
+.Lmovq\@:
+ movq %rax, MSG
+.Ldone\@:
+.endm
/*
- * __store_partial: internal ABI
- * input:
- * LEN - bytes
- * DST - dst
- * output:
- * T0 - message block
- * changed:
- * %r8
- * %r9
- * %r10
+ * Store 1 <= LEN (%ecx) <= 15 bytes from the xmm register \msg to the pointer
+ * DST. Clobbers %rax, %rcx, and %r8.
*/
-SYM_FUNC_START_LOCAL(__store_partial)
- .set LEN, %ecx
- .set DST, %rdx
- mov LEN, %r8d
- mov DST, %r9
-
- movq T0, %r10
-
- cmp $8, %r8
- jl .Lst_partial_8
-
- mov %r10, (%r9)
- psrldq $8, T0
- movq T0, %r10
-
- sub $8, %r8
- add $8, %r9
-
-.Lst_partial_8:
- cmp $4, %r8
- jl .Lst_partial_4
-
- mov %r10d, (%r9)
- shr $32, %r10
-
- sub $4, %r8
- add $4, %r9
-
-.Lst_partial_4:
- cmp $2, %r8
- jl .Lst_partial_2
-
- mov %r10w, (%r9)
- shr $0x10, %r10
-
- sub $2, %r8
- add $2, %r9
-
-.Lst_partial_2:
- cmp $1, %r8
- jl .Lst_partial_1
-
- mov %r10b, (%r9)
-
-.Lst_partial_1:
- RET
-SYM_FUNC_END(__store_partial)
+.macro store_partial msg
+ sub $8, %ecx /* LEN - 8 */
+ jl .Llt8\@
+
+ /* Store 8 <= LEN <= 15 bytes: */
+ pextrq $1, \msg, %rax
+ mov %ecx, %r8d
+ shl $3, %ecx
+ ror %cl, %rax
+ mov %rax, (DST, %r8) /* Store last LEN - 8 bytes */
+ movq \msg, (DST) /* Store first 8 bytes */
+ jmp .Ldone\@
+
+.Llt8\@:
+ add $4, %ecx /* LEN - 4 */
+ jl .Llt4\@
+
+ /* Store 4 <= LEN <= 7 bytes: */
+ pextrd $1, \msg, %eax
+ mov %ecx, %r8d
+ shl $3, %ecx
+ ror %cl, %eax
+ mov %eax, (DST, %r8) /* Store last LEN - 4 bytes */
+ movd \msg, (DST) /* Store first 4 bytes */
+ jmp .Ldone\@
+
+.Llt4\@:
+ /* Store 1 <= LEN <= 3 bytes: */
+ pextrb $0, \msg, 0(DST)
+ cmp $-2, %ecx /* LEN - 4 == -2, i.e. LEN == 2? */
+ jl .Ldone\@
+ pextrb $1, \msg, 1(DST)
+ je .Ldone\@
+ pextrb $2, \msg, 2(DST)
+.Ldone\@:
+.endm
/*
* void aegis128_aesni_init(struct aegis_state *state,
* const struct aegis_block *key,
* const u8 iv[AEGIS128_NONCE_SIZE]);
@@ -451,31 +406,33 @@ SYM_FUNC_END(aegis128_aesni_enc)
*/
SYM_FUNC_START(aegis128_aesni_enc_tail)
.set STATEP, %rdi
.set SRC, %rsi
.set DST, %rdx
- .set LEN, %ecx
+ .set LEN, %ecx /* {load,store}_partial rely on this being %ecx */
FRAME_BEGIN
/* load the state: */
movdqu 0x00(STATEP), STATE0
movdqu 0x10(STATEP), STATE1
movdqu 0x20(STATEP), STATE2
movdqu 0x30(STATEP), STATE3
movdqu 0x40(STATEP), STATE4
/* encrypt message: */
- call __load_partial
+ mov LEN, %r9d
+ load_partial
movdqa MSG, T0
pxor STATE1, T0
pxor STATE4, T0
movdqa STATE2, T1
pand STATE3, T1
pxor T1, T0
- call __store_partial
+ mov %r9d, LEN
+ store_partial T0
aegis128_update
pxor MSG, STATE4
/* store the state: */
@@ -596,40 +553,37 @@ SYM_FUNC_END(aegis128_aesni_dec)
*/
SYM_FUNC_START(aegis128_aesni_dec_tail)
.set STATEP, %rdi
.set SRC, %rsi
.set DST, %rdx
- .set LEN, %ecx
+ .set LEN, %ecx /* {load,store}_partial rely on this being %ecx */
FRAME_BEGIN
/* load the state: */
movdqu 0x00(STATEP), STATE0
movdqu 0x10(STATEP), STATE1
movdqu 0x20(STATEP), STATE2
movdqu 0x30(STATEP), STATE3
movdqu 0x40(STATEP), STATE4
/* decrypt message: */
- call __load_partial
+ mov LEN, %r9d
+ load_partial
pxor STATE1, MSG
pxor STATE4, MSG
movdqa STATE2, T1
pand STATE3, T1
pxor T1, MSG
- movdqa MSG, T0
- call __store_partial
+ mov %r9d, LEN
+ store_partial MSG
/* mask with byte count: */
- movd LEN, T0
- punpcklbw T0, T0
- punpcklbw T0, T0
- punpcklbw T0, T0
- punpcklbw T0, T0
- movdqa .Laegis128_counter(%rip), T1
- pcmpgtb T1, T0
+ lea .Lzeropad_mask+16(%rip), %rax
+ sub %r9, %rax
+ movdqu (%rax), T0
pand T0, MSG
aegis128_update
pxor MSG, STATE4