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-rw-r--r--src/crypto/elliptic/p256_ppc64le.go522
1 files changed, 522 insertions, 0 deletions
diff --git a/src/crypto/elliptic/p256_ppc64le.go b/src/crypto/elliptic/p256_ppc64le.go
new file mode 100644
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--- /dev/null
+++ b/src/crypto/elliptic/p256_ppc64le.go
@@ -0,0 +1,522 @@
+// Copyright 2019 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.
+
+//go:build ppc64le
+// +build ppc64le
+
+package elliptic
+
+import (
+ "crypto/subtle"
+ "encoding/binary"
+ "math/big"
+)
+
+// This was ported from the s390x implementation for ppc64le.
+// Some hints are included here for changes that should be
+// in the big endian ppc64 implementation, however more
+// investigation and testing is needed for the ppc64 big
+// endian version to work.
+type p256CurveFast struct {
+ *CurveParams
+}
+
+type p256Point struct {
+ x [32]byte
+ y [32]byte
+ z [32]byte
+}
+
+var (
+ p256 Curve
+ p256PreFast *[37][64]p256Point
+)
+
+func initP256Arch() {
+ p256 = p256CurveFast{p256Params}
+ initTable()
+ return
+}
+
+func (curve p256CurveFast) Params() *CurveParams {
+ return curve.CurveParams
+}
+
+// Functions implemented in p256_asm_ppc64le.s
+// Montgomery multiplication modulo P256
+//
+//go:noescape
+func p256MulAsm(res, in1, in2 []byte)
+
+// Montgomery square modulo P256
+//
+func p256Sqr(res, in []byte) {
+ p256MulAsm(res, in, in)
+}
+
+// Montgomery multiplication by 1
+//
+//go:noescape
+func p256FromMont(res, in []byte)
+
+// iff cond == 1 val <- -val
+//
+//go:noescape
+func p256NegCond(val *p256Point, cond int)
+
+// if cond == 0 res <- b; else res <- a
+//
+//go:noescape
+func p256MovCond(res, a, b *p256Point, cond int)
+
+// Constant time table access
+//
+//go:noescape
+func p256Select(point *p256Point, table []p256Point, idx int)
+
+//
+//go:noescape
+func p256SelectBase(point *p256Point, table []p256Point, idx int)
+
+// Point add with P2 being affine point
+// If sign == 1 -> P2 = -P2
+// If sel == 0 -> P3 = P1
+// if zero == 0 -> P3 = P2
+//
+//go:noescape
+func p256PointAddAffineAsm(res, in1, in2 *p256Point, sign, sel, zero int)
+
+// Point add
+//
+//go:noescape
+func p256PointAddAsm(res, in1, in2 *p256Point) int
+
+//
+//go:noescape
+func p256PointDoubleAsm(res, in *p256Point)
+
+// The result should be a slice in LE order, but the slice
+// from big.Bytes is in BE order.
+// TODO: For big endian implementation, do not reverse bytes.
+//
+func fromBig(big *big.Int) []byte {
+ // This could be done a lot more efficiently...
+ res := big.Bytes()
+ t := make([]byte, 32)
+ if len(res) < 32 {
+ copy(t[32-len(res):], res)
+ } else if len(res) == 32 {
+ copy(t, res)
+ } else {
+ copy(t, res[len(res)-32:])
+ }
+ p256ReverseBytes(t, t)
+ return t
+}
+
+// p256GetMultiplier makes sure byte array will have 32 byte elements, If the scalar
+// is equal or greater than the order of the group, it's reduced modulo that order.
+func p256GetMultiplier(in []byte) []byte {
+ n := new(big.Int).SetBytes(in)
+
+ if n.Cmp(p256Params.N) >= 0 {
+ n.Mod(n, p256Params.N)
+ }
+ return fromBig(n)
+}
+
+// p256MulAsm operates in a Montgomery domain with R = 2^256 mod p, where p is the
+// underlying field of the curve. (See initP256 for the value.) Thus rr here is
+// R×R mod p. See comment in Inverse about how this is used.
+// TODO: For big endian implementation, the bytes in these slices should be in reverse order,
+// as found in the s390x implementation.
+var rr = []byte{0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0, 0xff, 0xff, 0xff, 0xff, 0xfb, 0xff, 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0x04, 0x00, 0x00, 0x00}
+
+// (This is one, in the Montgomery domain.)
+var one = []byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00}
+
+func maybeReduceModP(in *big.Int) *big.Int {
+ if in.Cmp(p256Params.P) < 0 {
+ return in
+ }
+ return new(big.Int).Mod(in, p256Params.P)
+}
+
+// p256ReverseBytes copies the first 32 bytes from in to res in reverse order.
+func p256ReverseBytes(res, in []byte) {
+ // remove bounds check
+ in = in[:32]
+ res = res[:32]
+
+ // Load in reverse order
+ a := binary.BigEndian.Uint64(in[0:])
+ b := binary.BigEndian.Uint64(in[8:])
+ c := binary.BigEndian.Uint64(in[16:])
+ d := binary.BigEndian.Uint64(in[24:])
+
+ // Store in normal order
+ binary.LittleEndian.PutUint64(res[0:], d)
+ binary.LittleEndian.PutUint64(res[8:], c)
+ binary.LittleEndian.PutUint64(res[16:], b)
+ binary.LittleEndian.PutUint64(res[24:], a)
+}
+
+func (curve p256CurveFast) CombinedMult(bigX, bigY *big.Int, baseScalar, scalar []byte) (x, y *big.Int) {
+ var r1, r2 p256Point
+
+ scalarReduced := p256GetMultiplier(baseScalar)
+ r1IsInfinity := scalarIsZero(scalarReduced)
+ r1.p256BaseMult(scalarReduced)
+
+ copy(r2.x[:], fromBig(maybeReduceModP(bigX)))
+ copy(r2.y[:], fromBig(maybeReduceModP(bigY)))
+ copy(r2.z[:], one)
+ p256MulAsm(r2.x[:], r2.x[:], rr[:])
+ p256MulAsm(r2.y[:], r2.y[:], rr[:])
+
+ scalarReduced = p256GetMultiplier(scalar)
+ r2IsInfinity := scalarIsZero(scalarReduced)
+ r2.p256ScalarMult(scalarReduced)
+
+ var sum, double p256Point
+ pointsEqual := p256PointAddAsm(&sum, &r1, &r2)
+ p256PointDoubleAsm(&double, &r1)
+ p256MovCond(&sum, &double, &sum, pointsEqual)
+ p256MovCond(&sum, &r1, &sum, r2IsInfinity)
+ p256MovCond(&sum, &r2, &sum, r1IsInfinity)
+ return sum.p256PointToAffine()
+}
+
+func (curve p256CurveFast) ScalarBaseMult(scalar []byte) (x, y *big.Int) {
+ var r p256Point
+ reducedScalar := p256GetMultiplier(scalar)
+ r.p256BaseMult(reducedScalar)
+ return r.p256PointToAffine()
+}
+
+func (curve p256CurveFast) ScalarMult(bigX, bigY *big.Int, scalar []byte) (x, y *big.Int) {
+ scalarReduced := p256GetMultiplier(scalar)
+ var r p256Point
+ copy(r.x[:], fromBig(maybeReduceModP(bigX)))
+ copy(r.y[:], fromBig(maybeReduceModP(bigY)))
+ copy(r.z[:], one)
+ p256MulAsm(r.x[:], r.x[:], rr[:])
+ p256MulAsm(r.y[:], r.y[:], rr[:])
+ r.p256ScalarMult(scalarReduced)
+ return r.p256PointToAffine()
+}
+
+func scalarIsZero(scalar []byte) int {
+ // If any byte is not zero, return 0.
+ // Check for -0.... since that appears to compare to 0.
+ b := byte(0)
+ for _, s := range scalar {
+ b |= s
+ }
+ return subtle.ConstantTimeByteEq(b, 0)
+}
+
+func (p *p256Point) p256PointToAffine() (x, y *big.Int) {
+ zInv := make([]byte, 32)
+ zInvSq := make([]byte, 32)
+
+ p256Inverse(zInv, p.z[:])
+ p256Sqr(zInvSq, zInv)
+ p256MulAsm(zInv, zInv, zInvSq)
+
+ p256MulAsm(zInvSq, p.x[:], zInvSq)
+ p256MulAsm(zInv, p.y[:], zInv)
+
+ p256FromMont(zInvSq, zInvSq)
+ p256FromMont(zInv, zInv)
+
+ // SetBytes expects a slice in big endian order,
+ // since ppc64le is little endian, reverse the bytes.
+ // TODO: For big endian, bytes don't need to be reversed.
+ p256ReverseBytes(zInvSq, zInvSq)
+ p256ReverseBytes(zInv, zInv)
+ rx := new(big.Int).SetBytes(zInvSq)
+ ry := new(big.Int).SetBytes(zInv)
+ return rx, ry
+}
+
+// p256Inverse sets out to in^-1 mod p.
+func p256Inverse(out, in []byte) {
+ var stack [6 * 32]byte
+ p2 := stack[32*0 : 32*0+32]
+ p4 := stack[32*1 : 32*1+32]
+ p8 := stack[32*2 : 32*2+32]
+ p16 := stack[32*3 : 32*3+32]
+ p32 := stack[32*4 : 32*4+32]
+
+ p256Sqr(out, in)
+ p256MulAsm(p2, out, in) // 3*p
+
+ p256Sqr(out, p2)
+ p256Sqr(out, out)
+ p256MulAsm(p4, out, p2) // f*p
+
+ p256Sqr(out, p4)
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256MulAsm(p8, out, p4) // ff*p
+
+ p256Sqr(out, p8)
+
+ for i := 0; i < 7; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(p16, out, p8) // ffff*p
+
+ p256Sqr(out, p16)
+ for i := 0; i < 15; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(p32, out, p16) // ffffffff*p
+
+ p256Sqr(out, p32)
+
+ for i := 0; i < 31; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(out, out, in)
+
+ for i := 0; i < 32*4; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(out, out, p32)
+
+ for i := 0; i < 32; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(out, out, p32)
+
+ for i := 0; i < 16; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(out, out, p16)
+
+ for i := 0; i < 8; i++ {
+ p256Sqr(out, out)
+ }
+ p256MulAsm(out, out, p8)
+
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256MulAsm(out, out, p4)
+
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256MulAsm(out, out, p2)
+
+ p256Sqr(out, out)
+ p256Sqr(out, out)
+ p256MulAsm(out, out, in)
+}
+
+func boothW5(in uint) (int, int) {
+ var s uint = ^((in >> 5) - 1)
+ var d uint = (1 << 6) - in - 1
+ d = (d & s) | (in & (^s))
+ d = (d >> 1) + (d & 1)
+ return int(d), int(s & 1)
+}
+
+func boothW6(in uint) (int, int) {
+ var s uint = ^((in >> 6) - 1)
+ var d uint = (1 << 7) - in - 1
+ d = (d & s) | (in & (^s))
+ d = (d >> 1) + (d & 1)
+ return int(d), int(s & 1)
+}
+
+func boothW7(in uint) (int, int) {
+ var s uint = ^((in >> 7) - 1)
+ var d uint = (1 << 8) - in - 1
+ d = (d & s) | (in & (^s))
+ d = (d >> 1) + (d & 1)
+ return int(d), int(s & 1)
+}
+
+func initTable() {
+
+ p256PreFast = new([37][64]p256Point)
+
+ // TODO: For big endian, these slices should be in reverse byte order,
+ // as found in the s390x implementation.
+ basePoint := p256Point{
+ x: [32]byte{0x3c, 0x14, 0xa9, 0x18, 0xd4, 0x30, 0xe7, 0x79, 0x01, 0xb6, 0xed, 0x5f, 0xfc, 0x95, 0xba, 0x75,
+ 0x10, 0x25, 0x62, 0x77, 0x2b, 0x73, 0xfb, 0x79, 0xc6, 0x55, 0x37, 0xa5, 0x76, 0x5f, 0x90, 0x18}, //(p256.x*2^256)%p
+ y: [32]byte{0x0a, 0x56, 0x95, 0xce, 0x57, 0x53, 0xf2, 0xdd, 0x5c, 0xe4, 0x19, 0xba, 0xe4, 0xb8, 0x4a, 0x8b,
+ 0x25, 0xf3, 0x21, 0xdd, 0x88, 0x86, 0xe8, 0xd2, 0x85, 0x5d, 0x88, 0x25, 0x18, 0xff, 0x71, 0x85}, //(p256.y*2^256)%p
+ z: [32]byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00}, //(p256.z*2^256)%p
+
+ }
+
+ t1 := new(p256Point)
+ t2 := new(p256Point)
+ *t2 = basePoint
+
+ zInv := make([]byte, 32)
+ zInvSq := make([]byte, 32)
+ for j := 0; j < 64; j++ {
+ *t1 = *t2
+ for i := 0; i < 37; i++ {
+ // The window size is 7 so we need to double 7 times.
+ if i != 0 {
+ for k := 0; k < 7; k++ {
+ p256PointDoubleAsm(t1, t1)
+ }
+ }
+ // Convert the point to affine form. (Its values are
+ // still in Montgomery form however.)
+ p256Inverse(zInv, t1.z[:])
+ p256Sqr(zInvSq, zInv)
+ p256MulAsm(zInv, zInv, zInvSq)
+
+ p256MulAsm(t1.x[:], t1.x[:], zInvSq)
+ p256MulAsm(t1.y[:], t1.y[:], zInv)
+
+ copy(t1.z[:], basePoint.z[:])
+ // Update the table entry
+ copy(p256PreFast[i][j].x[:], t1.x[:])
+ copy(p256PreFast[i][j].y[:], t1.y[:])
+ }
+ if j == 0 {
+ p256PointDoubleAsm(t2, &basePoint)
+ } else {
+ p256PointAddAsm(t2, t2, &basePoint)
+ }
+ }
+}
+
+func (p *p256Point) p256BaseMult(scalar []byte) {
+ // TODO: For big endian, the index should be 31 not 0.
+ wvalue := (uint(scalar[0]) << 1) & 0xff
+ sel, sign := boothW7(uint(wvalue))
+ p256SelectBase(p, p256PreFast[0][:], sel)
+ p256NegCond(p, sign)
+
+ copy(p.z[:], one[:])
+ var t0 p256Point
+
+ copy(t0.z[:], one[:])
+
+ index := uint(6)
+ zero := sel
+ for i := 1; i < 37; i++ {
+ // TODO: For big endian, use the same index values as found
+ // in the s390x implementation.
+ if index < 247 {
+ wvalue = ((uint(scalar[index/8]) >> (index % 8)) + (uint(scalar[index/8+1]) << (8 - (index % 8)))) & 0xff
+ } else {
+ wvalue = (uint(scalar[index/8]) >> (index % 8)) & 0xff
+ }
+ index += 7
+ sel, sign = boothW7(uint(wvalue))
+ p256SelectBase(&t0, p256PreFast[i][:], sel)
+ p256PointAddAffineAsm(p, p, &t0, sign, sel, zero)
+ zero |= sel
+ }
+}
+
+func (p *p256Point) p256ScalarMult(scalar []byte) {
+ // precomp is a table of precomputed points that stores powers of p
+ // from p^1 to p^16.
+ var precomp [16]p256Point
+ var t0, t1, t2, t3 p256Point
+
+ *&precomp[0] = *p
+ p256PointDoubleAsm(&t0, p)
+ p256PointDoubleAsm(&t1, &t0)
+ p256PointDoubleAsm(&t2, &t1)
+ p256PointDoubleAsm(&t3, &t2)
+ *&precomp[1] = t0
+ *&precomp[3] = t1
+ *&precomp[7] = t2
+ *&precomp[15] = t3
+
+ p256PointAddAsm(&t0, &t0, p)
+ p256PointAddAsm(&t1, &t1, p)
+ p256PointAddAsm(&t2, &t2, p)
+
+ *&precomp[2] = t0
+ *&precomp[4] = t1
+ *&precomp[8] = t2
+
+ p256PointDoubleAsm(&t0, &t0)
+ p256PointDoubleAsm(&t1, &t1)
+ *&precomp[5] = t0
+ *&precomp[9] = t1
+
+ p256PointAddAsm(&t2, &t0, p)
+ p256PointAddAsm(&t1, &t1, p)
+ *&precomp[6] = t2
+ *&precomp[10] = t1
+
+ p256PointDoubleAsm(&t0, &t0)
+ p256PointDoubleAsm(&t2, &t2)
+ *&precomp[11] = t0
+ *&precomp[13] = t2
+
+ p256PointAddAsm(&t0, &t0, p)
+ p256PointAddAsm(&t2, &t2, p)
+ *&precomp[12] = t0
+ *&precomp[14] = t2
+
+ // Start scanning the window from top bit
+ index := uint(254)
+ var sel, sign int
+
+ // TODO: For big endian, use index found in s390x implementation.
+ wvalue := (uint(scalar[index/8]) >> (index % 8)) & 0x3f
+ sel, _ = boothW5(uint(wvalue))
+ p256Select(p, precomp[:], sel)
+ zero := sel
+
+ for index > 4 {
+ index -= 5
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+
+ // TODO: For big endian, use index values as found in s390x implementation.
+ if index < 247 {
+ wvalue = ((uint(scalar[index/8]) >> (index % 8)) + (uint(scalar[index/8+1]) << (8 - (index % 8)))) & 0x3f
+ } else {
+ wvalue = (uint(scalar[index/8]) >> (index % 8)) & 0x3f
+ }
+
+ sel, sign = boothW5(uint(wvalue))
+
+ p256Select(&t0, precomp[:], sel)
+ p256NegCond(&t0, sign)
+ p256PointAddAsm(&t1, p, &t0)
+ p256MovCond(&t1, &t1, p, sel)
+ p256MovCond(p, &t1, &t0, zero)
+ zero |= sel
+ }
+
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+ p256PointDoubleAsm(p, p)
+
+ // TODO: Use index for big endian as found in s390x implementation.
+ wvalue = (uint(scalar[0]) << 1) & 0x3f
+ sel, sign = boothW5(uint(wvalue))
+
+ p256Select(&t0, precomp[:], sel)
+ p256NegCond(&t0, sign)
+ p256PointAddAsm(&t1, p, &t0)
+ p256MovCond(&t1, &t1, p, sel)
+ p256MovCond(p, &t1, &t0, zero)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-11 01:49:32 +0000