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Diffstat (limited to 'vendor/golang.org/x/crypto/curve25519/curve25519_amd64.go')
-rw-r--r--vendor/golang.org/x/crypto/curve25519/curve25519_amd64.go240
1 files changed, 240 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/curve25519/curve25519_amd64.go b/vendor/golang.org/x/crypto/curve25519/curve25519_amd64.go
new file mode 100644
index 000000000..5120b779b
--- /dev/null
+++ b/vendor/golang.org/x/crypto/curve25519/curve25519_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,!purego
+
+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 */
+}