poly1305: implement a subset of the hash.Hash interface

This CL adds the poly1305.MAC type which implements a
subset of the hash.Hash interface. With MAC it is possible
to compute an authentication tag of data without copying
it into a single byte slice.

This commit modifies the reference/generic and the
AMD64 assembler but not the ARM/s390x implementation
to support an io.Writer interface.

Updates golang/go#25219

Change-Id: I7ee5a9eadd43387cf3cd887d734c625575eee47d
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/111335
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
This commit is contained in:
Andreas Auernhammer
2019-03-08 22:17:18 +00:00
committed by Filippo Valsorda
parent 8dd112bcdc
commit c2843e01d9
7 changed files with 322 additions and 92 deletions
+42 -19
View File
@@ -58,20 +58,17 @@ DATA ·poly1305Mask<>+0x00(SB)/8, $0x0FFFFFFC0FFFFFFF
DATA ·poly1305Mask<>+0x08(SB)/8, $0x0FFFFFFC0FFFFFFC
GLOBL ·poly1305Mask<>(SB), RODATA, $16
// func poly1305(out *[16]byte, m *byte, mlen uint64, key *[32]key)
TEXT ·poly1305(SB), $0-32
MOVQ out+0(FP), DI
MOVQ m+8(FP), SI
MOVQ mlen+16(FP), R15
MOVQ key+24(FP), AX
// func update(state *[7]uint64, msg []byte)
TEXT ·update(SB), $0-32
MOVQ state+0(FP), DI
MOVQ msg_base+8(FP), SI
MOVQ msg_len+16(FP), R15
MOVQ 0(AX), R11
MOVQ 8(AX), R12
ANDQ ·poly1305Mask<>(SB), R11 // r0
ANDQ ·poly1305Mask<>+8(SB), R12 // r1
XORQ R8, R8 // h0
XORQ R9, R9 // h1
XORQ R10, R10 // h2
MOVQ 0(DI), R8 // h0
MOVQ 8(DI), R9 // h1
MOVQ 16(DI), R10 // h2
MOVQ 24(DI), R11 // r0
MOVQ 32(DI), R12 // r1
CMPQ R15, $16
JB bytes_between_0_and_15
@@ -109,16 +106,42 @@ flush_buffer:
JMP multiply
done:
MOVQ R8, AX
MOVQ R9, BX
MOVQ R8, 0(DI)
MOVQ R9, 8(DI)
MOVQ R10, 16(DI)
RET
// func initialize(state *[7]uint64, key *[32]byte)
TEXT ·initialize(SB), $0-16
MOVQ state+0(FP), DI
MOVQ key+8(FP), SI
// state[0...7] is initialized with zero
MOVOU 0(SI), X0
MOVOU 16(SI), X1
MOVOU ·poly1305Mask<>(SB), X2
PAND X2, X0
MOVOU X0, 24(DI)
MOVOU X1, 40(DI)
RET
// func finalize(tag *[TagSize]byte, state *[7]uint64)
TEXT ·finalize(SB), $0-16
MOVQ tag+0(FP), DI
MOVQ state+8(FP), SI
MOVQ 0(SI), AX
MOVQ 8(SI), BX
MOVQ 16(SI), CX
MOVQ AX, R8
MOVQ BX, R9
SUBQ $0xFFFFFFFFFFFFFFFB, AX
SBBQ $0xFFFFFFFFFFFFFFFF, BX
SBBQ $3, R10
SBBQ $3, CX
CMOVQCS R8, AX
CMOVQCS R9, BX
MOVQ key+24(FP), R8
ADDQ 16(R8), AX
ADCQ 24(R8), BX
ADDQ 40(SI), AX
ADCQ 48(SI), BX
MOVQ AX, 0(DI)
MOVQ BX, 8(DI)