[PATCH 1/7] crypto: aesni: make non-AVX AES-GCM work with any aadlen

From: Sabrina Dubroca
Date: Fri Apr 28 2017 - 12:16:10 EST


This is the first step to make the aesni AES-GCM implementation
generic. The current code was written for rfc4106, so it handles only
some specific sizes of associated data.

Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
---
arch/x86/crypto/aesni-intel_asm.S | 169 +++++++++++++++++++++++++++++---------
1 file changed, 132 insertions(+), 37 deletions(-)

diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index 3c465184ff8a..605726aaf0a2 100644
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -89,6 +89,29 @@ SHIFT_MASK: .octa 0x0f0e0d0c0b0a09080706050403020100
ALL_F: .octa 0xffffffffffffffffffffffffffffffff
.octa 0x00000000000000000000000000000000

+.section .rodata
+.align 16
+.type aad_shift_arr, @object
+.size aad_shift_arr, 272
+aad_shift_arr:
+ .octa 0xffffffffffffffffffffffffffffffff
+ .octa 0xffffffffffffffffffffffffffffff0C
+ .octa 0xffffffffffffffffffffffffffff0D0C
+ .octa 0xffffffffffffffffffffffffff0E0D0C
+ .octa 0xffffffffffffffffffffffff0F0E0D0C
+ .octa 0xffffffffffffffffffffff0C0B0A0908
+ .octa 0xffffffffffffffffffff0D0C0B0A0908
+ .octa 0xffffffffffffffffff0E0D0C0B0A0908
+ .octa 0xffffffffffffffff0F0E0D0C0B0A0908
+ .octa 0xffffffffffffff0C0B0A090807060504
+ .octa 0xffffffffffff0D0C0B0A090807060504
+ .octa 0xffffffffff0E0D0C0B0A090807060504
+ .octa 0xffffffff0F0E0D0C0B0A090807060504
+ .octa 0xffffff0C0B0A09080706050403020100
+ .octa 0xffff0D0C0B0A09080706050403020100
+ .octa 0xff0E0D0C0B0A09080706050403020100
+ .octa 0x0F0E0D0C0B0A09080706050403020100
+

.text

@@ -252,32 +275,66 @@ XMM2 XMM3 XMM4 XMMDst TMP6 TMP7 i i_seq operation
mov arg8, %r12 # %r12 = aadLen
mov %r12, %r11
pxor %xmm\i, %xmm\i
+ pxor \XMM2, \XMM2

-_get_AAD_loop\num_initial_blocks\operation:
- movd (%r10), \TMP1
- pslldq $12, \TMP1
- psrldq $4, %xmm\i
+ cmp $16, %r11
+ jl _get_AAD_rest8\num_initial_blocks\operation
+_get_AAD_blocks\num_initial_blocks\operation:
+ movdqu (%r10), %xmm\i
+ PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data
+ pxor %xmm\i, \XMM2
+ GHASH_MUL \XMM2, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1
+ add $16, %r10
+ sub $16, %r12
+ sub $16, %r11
+ cmp $16, %r11
+ jge _get_AAD_blocks\num_initial_blocks\operation
+
+ movdqu \XMM2, %xmm\i
+ cmp $0, %r11
+ je _get_AAD_done\num_initial_blocks\operation
+
+ pxor %xmm\i,%xmm\i
+
+ /* read the last <16B of AAD. since we have at least 4B of
+ data right after the AAD (the ICV, and maybe some CT), we can
+ read 4B/8B blocks safely, and then get rid of the extra stuff */
+_get_AAD_rest8\num_initial_blocks\operation:
+ cmp $4, %r11
+ jle _get_AAD_rest4\num_initial_blocks\operation
+ movq (%r10), \TMP1
+ add $8, %r10
+ sub $8, %r11
+ pslldq $8, \TMP1
+ psrldq $8, %xmm\i
pxor \TMP1, %xmm\i
+ jmp _get_AAD_rest8\num_initial_blocks\operation
+_get_AAD_rest4\num_initial_blocks\operation:
+ cmp $0, %r11
+ jle _get_AAD_rest0\num_initial_blocks\operation
+ mov (%r10), %eax
+ movq %rax, \TMP1
add $4, %r10
- sub $4, %r12
- jne _get_AAD_loop\num_initial_blocks\operation
-
- cmp $16, %r11
- je _get_AAD_loop2_done\num_initial_blocks\operation
-
- mov $16, %r12
-_get_AAD_loop2\num_initial_blocks\operation:
+ sub $4, %r10
+ pslldq $12, \TMP1
psrldq $4, %xmm\i
- sub $4, %r12
- cmp %r11, %r12
- jne _get_AAD_loop2\num_initial_blocks\operation
-
-_get_AAD_loop2_done\num_initial_blocks\operation:
+ pxor \TMP1, %xmm\i
+_get_AAD_rest0\num_initial_blocks\operation:
+ /* finalize: shift out the extra bytes we read, and align
+ left. since pslldq can only shift by an immediate, we use
+ vpshufb and an array of shuffle masks */
+ movq %r12, %r11
+ salq $4, %r11
+ movdqu aad_shift_arr(%r11), \TMP1
+ PSHUFB_XMM \TMP1, %xmm\i
+_get_AAD_rest_final\num_initial_blocks\operation:
PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data
+ pxor \XMM2, %xmm\i
+ GHASH_MUL %xmm\i, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1

+_get_AAD_done\num_initial_blocks\operation:
xor %r11, %r11 # initialise the data pointer offset as zero
-
- # start AES for num_initial_blocks blocks
+ # start AES for num_initial_blocks blocks

mov %arg5, %rax # %rax = *Y0
movdqu (%rax), \XMM0 # XMM0 = Y0
@@ -322,7 +379,7 @@ XMM2 XMM3 XMM4 XMMDst TMP6 TMP7 i i_seq operation
# prepare plaintext/ciphertext for GHASH computation
.endr
.endif
- GHASH_MUL %xmm\i, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1
+
# apply GHASH on num_initial_blocks blocks

.if \i == 5
@@ -477,28 +534,66 @@ XMM2 XMM3 XMM4 XMMDst TMP6 TMP7 i i_seq operation
mov arg8, %r12 # %r12 = aadLen
mov %r12, %r11
pxor %xmm\i, %xmm\i
-_get_AAD_loop\num_initial_blocks\operation:
- movd (%r10), \TMP1
- pslldq $12, \TMP1
- psrldq $4, %xmm\i
+ pxor \XMM2, \XMM2
+
+ cmp $16, %r11
+ jl _get_AAD_rest8\num_initial_blocks\operation
+_get_AAD_blocks\num_initial_blocks\operation:
+ movdqu (%r10), %xmm\i
+ PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data
+ pxor %xmm\i, \XMM2
+ GHASH_MUL \XMM2, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1
+ add $16, %r10
+ sub $16, %r12
+ sub $16, %r11
+ cmp $16, %r11
+ jge _get_AAD_blocks\num_initial_blocks\operation
+
+ movdqu \XMM2, %xmm\i
+ cmp $0, %r11
+ je _get_AAD_done\num_initial_blocks\operation
+
+ pxor %xmm\i,%xmm\i
+
+ /* read the last <16B of AAD. since we have at least 4B of
+ data right after the AAD (the ICV, and maybe some PT), we can
+ read 4B/8B blocks safely, and then get rid of the extra stuff */
+_get_AAD_rest8\num_initial_blocks\operation:
+ cmp $4, %r11
+ jle _get_AAD_rest4\num_initial_blocks\operation
+ movq (%r10), \TMP1
+ add $8, %r10
+ sub $8, %r11
+ pslldq $8, \TMP1
+ psrldq $8, %xmm\i
pxor \TMP1, %xmm\i
+ jmp _get_AAD_rest8\num_initial_blocks\operation
+_get_AAD_rest4\num_initial_blocks\operation:
+ cmp $0, %r11
+ jle _get_AAD_rest0\num_initial_blocks\operation
+ mov (%r10), %eax
+ movq %rax, \TMP1
add $4, %r10
- sub $4, %r12
- jne _get_AAD_loop\num_initial_blocks\operation
- cmp $16, %r11
- je _get_AAD_loop2_done\num_initial_blocks\operation
- mov $16, %r12
-_get_AAD_loop2\num_initial_blocks\operation:
+ sub $4, %r10
+ pslldq $12, \TMP1
psrldq $4, %xmm\i
- sub $4, %r12
- cmp %r11, %r12
- jne _get_AAD_loop2\num_initial_blocks\operation
-_get_AAD_loop2_done\num_initial_blocks\operation:
+ pxor \TMP1, %xmm\i
+_get_AAD_rest0\num_initial_blocks\operation:
+ /* finalize: shift out the extra bytes we read, and align
+ left. since pslldq can only shift by an immediate, we use
+ vpshufb and an array of shuffle masks */
+ movq %r12, %r11
+ salq $4, %r11
+ movdqu aad_shift_arr(%r11), \TMP1
+ PSHUFB_XMM \TMP1, %xmm\i
+_get_AAD_rest_final\num_initial_blocks\operation:
PSHUFB_XMM %xmm14, %xmm\i # byte-reflect the AAD data
+ pxor \XMM2, %xmm\i
+ GHASH_MUL %xmm\i, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1

+_get_AAD_done\num_initial_blocks\operation:
xor %r11, %r11 # initialise the data pointer offset as zero
-
- # start AES for num_initial_blocks blocks
+ # start AES for num_initial_blocks blocks

mov %arg5, %rax # %rax = *Y0
movdqu (%rax), \XMM0 # XMM0 = Y0
@@ -543,7 +638,7 @@ XMM2 XMM3 XMM4 XMMDst TMP6 TMP7 i i_seq operation
# prepare plaintext/ciphertext for GHASH computation
.endr
.endif
- GHASH_MUL %xmm\i, \TMP3, \TMP1, \TMP2, \TMP4, \TMP5, \XMM1
+
# apply GHASH on num_initial_blocks blocks

.if \i == 5
--
2.12.2