From 649bf79117e30895108b7782d62daafd07bc5e6e Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 22 May 2016 01:23:33 +0100 Subject: Use govendor --- .../x/crypto/curve25519/mont25519_amd64.go | 240 +++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100644 vendor/golang.org/x/crypto/curve25519/mont25519_amd64.go (limited to 'vendor/golang.org/x/crypto/curve25519/mont25519_amd64.go') diff --git a/vendor/golang.org/x/crypto/curve25519/mont25519_amd64.go b/vendor/golang.org/x/crypto/curve25519/mont25519_amd64.go new file mode 100644 index 0000000..5822bd5 --- /dev/null +++ b/vendor/golang.org/x/crypto/curve25519/mont25519_amd64.go @@ -0,0 +1,240 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build amd64,!gccgo,!appengine + +package curve25519 + +// These functions are implemented in the .s files. The names of the functions +// in the rest of the file are also taken from the SUPERCOP sources to help +// people following along. + +//go:noescape + +func cswap(inout *[5]uint64, v uint64) + +//go:noescape + +func ladderstep(inout *[5][5]uint64) + +//go:noescape + +func freeze(inout *[5]uint64) + +//go:noescape + +func mul(dest, a, b *[5]uint64) + +//go:noescape + +func square(out, in *[5]uint64) + +// mladder uses a Montgomery ladder to calculate (xr/zr) *= s. +func mladder(xr, zr *[5]uint64, s *[32]byte) { + var work [5][5]uint64 + + work[0] = *xr + setint(&work[1], 1) + setint(&work[2], 0) + work[3] = *xr + setint(&work[4], 1) + + j := uint(6) + var prevbit byte + + for i := 31; i >= 0; i-- { + for j < 8 { + bit := ((*s)[i] >> j) & 1 + swap := bit ^ prevbit + prevbit = bit + cswap(&work[1], uint64(swap)) + ladderstep(&work) + j-- + } + j = 7 + } + + *xr = work[1] + *zr = work[2] +} + +func scalarMult(out, in, base *[32]byte) { + var e [32]byte + copy(e[:], (*in)[:]) + e[0] &= 248 + e[31] &= 127 + e[31] |= 64 + + var t, z [5]uint64 + unpack(&t, base) + mladder(&t, &z, &e) + invert(&z, &z) + mul(&t, &t, &z) + pack(out, &t) +} + +func setint(r *[5]uint64, v uint64) { + r[0] = v + r[1] = 0 + r[2] = 0 + r[3] = 0 + r[4] = 0 +} + +// unpack sets r = x where r consists of 5, 51-bit limbs in little-endian +// order. +func unpack(r *[5]uint64, x *[32]byte) { + r[0] = uint64(x[0]) | + uint64(x[1])<<8 | + uint64(x[2])<<16 | + uint64(x[3])<<24 | + uint64(x[4])<<32 | + uint64(x[5])<<40 | + uint64(x[6]&7)<<48 + + r[1] = uint64(x[6])>>3 | + uint64(x[7])<<5 | + uint64(x[8])<<13 | + uint64(x[9])<<21 | + uint64(x[10])<<29 | + uint64(x[11])<<37 | + uint64(x[12]&63)<<45 + + r[2] = uint64(x[12])>>6 | + uint64(x[13])<<2 | + uint64(x[14])<<10 | + uint64(x[15])<<18 | + uint64(x[16])<<26 | + uint64(x[17])<<34 | + uint64(x[18])<<42 | + uint64(x[19]&1)<<50 + + r[3] = uint64(x[19])>>1 | + uint64(x[20])<<7 | + uint64(x[21])<<15 | + uint64(x[22])<<23 | + uint64(x[23])<<31 | + uint64(x[24])<<39 | + uint64(x[25]&15)<<47 + + r[4] = uint64(x[25])>>4 | + uint64(x[26])<<4 | + uint64(x[27])<<12 | + uint64(x[28])<<20 | + uint64(x[29])<<28 | + uint64(x[30])<<36 | + uint64(x[31]&127)<<44 +} + +// pack sets out = x where out is the usual, little-endian form of the 5, +// 51-bit limbs in x. +func pack(out *[32]byte, x *[5]uint64) { + t := *x + freeze(&t) + + out[0] = byte(t[0]) + out[1] = byte(t[0] >> 8) + out[2] = byte(t[0] >> 16) + out[3] = byte(t[0] >> 24) + out[4] = byte(t[0] >> 32) + out[5] = byte(t[0] >> 40) + out[6] = byte(t[0] >> 48) + + out[6] ^= byte(t[1]<<3) & 0xf8 + out[7] = byte(t[1] >> 5) + out[8] = byte(t[1] >> 13) + out[9] = byte(t[1] >> 21) + out[10] = byte(t[1] >> 29) + out[11] = byte(t[1] >> 37) + out[12] = byte(t[1] >> 45) + + out[12] ^= byte(t[2]<<6) & 0xc0 + out[13] = byte(t[2] >> 2) + out[14] = byte(t[2] >> 10) + out[15] = byte(t[2] >> 18) + out[16] = byte(t[2] >> 26) + out[17] = byte(t[2] >> 34) + out[18] = byte(t[2] >> 42) + out[19] = byte(t[2] >> 50) + + out[19] ^= byte(t[3]<<1) & 0xfe + out[20] = byte(t[3] >> 7) + out[21] = byte(t[3] >> 15) + out[22] = byte(t[3] >> 23) + out[23] = byte(t[3] >> 31) + out[24] = byte(t[3] >> 39) + out[25] = byte(t[3] >> 47) + + out[25] ^= byte(t[4]<<4) & 0xf0 + out[26] = byte(t[4] >> 4) + out[27] = byte(t[4] >> 12) + out[28] = byte(t[4] >> 20) + out[29] = byte(t[4] >> 28) + out[30] = byte(t[4] >> 36) + out[31] = byte(t[4] >> 44) +} + +// invert calculates r = x^-1 mod p using Fermat's little theorem. +func invert(r *[5]uint64, x *[5]uint64) { + var z2, z9, z11, z2_5_0, z2_10_0, z2_20_0, z2_50_0, z2_100_0, t [5]uint64 + + square(&z2, x) /* 2 */ + square(&t, &z2) /* 4 */ + square(&t, &t) /* 8 */ + mul(&z9, &t, x) /* 9 */ + mul(&z11, &z9, &z2) /* 11 */ + square(&t, &z11) /* 22 */ + mul(&z2_5_0, &t, &z9) /* 2^5 - 2^0 = 31 */ + + square(&t, &z2_5_0) /* 2^6 - 2^1 */ + for i := 1; i < 5; i++ { /* 2^20 - 2^10 */ + square(&t, &t) + } + mul(&z2_10_0, &t, &z2_5_0) /* 2^10 - 2^0 */ + + square(&t, &z2_10_0) /* 2^11 - 2^1 */ + for i := 1; i < 10; i++ { /* 2^20 - 2^10 */ + square(&t, &t) + } + mul(&z2_20_0, &t, &z2_10_0) /* 2^20 - 2^0 */ + + square(&t, &z2_20_0) /* 2^21 - 2^1 */ + for i := 1; i < 20; i++ { /* 2^40 - 2^20 */ + square(&t, &t) + } + mul(&t, &t, &z2_20_0) /* 2^40 - 2^0 */ + + square(&t, &t) /* 2^41 - 2^1 */ + for i := 1; i < 10; i++ { /* 2^50 - 2^10 */ + square(&t, &t) + } + mul(&z2_50_0, &t, &z2_10_0) /* 2^50 - 2^0 */ + + square(&t, &z2_50_0) /* 2^51 - 2^1 */ + for i := 1; i < 50; i++ { /* 2^100 - 2^50 */ + square(&t, &t) + } + mul(&z2_100_0, &t, &z2_50_0) /* 2^100 - 2^0 */ + + square(&t, &z2_100_0) /* 2^101 - 2^1 */ + for i := 1; i < 100; i++ { /* 2^200 - 2^100 */ + square(&t, &t) + } + mul(&t, &t, &z2_100_0) /* 2^200 - 2^0 */ + + square(&t, &t) /* 2^201 - 2^1 */ + for i := 1; i < 50; i++ { /* 2^250 - 2^50 */ + square(&t, &t) + } + mul(&t, &t, &z2_50_0) /* 2^250 - 2^0 */ + + square(&t, &t) /* 2^251 - 2^1 */ + square(&t, &t) /* 2^252 - 2^2 */ + square(&t, &t) /* 2^253 - 2^3 */ + + square(&t, &t) /* 2^254 - 2^4 */ + + square(&t, &t) /* 2^255 - 2^5 */ + mul(r, &t, &z11) /* 2^255 - 21 */ +} -- cgit v1.2.3