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#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
#pragma warning disable
using System;
using System.Diagnostics;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Digests;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Math.EC.Rfc7748;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Math.Raw;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Security;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities;
namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Math.EC.Rfc8032
{
public abstract class Ed25519
{
// -x^2 + y^2 == 1 + 0x52036CEE2B6FFE738CC740797779E89800700A4D4141D8AB75EB4DCA135978A3 * x^2 * y^2
public enum Algorithm
{
Ed25519 = 0,
Ed25519ctx = 1,
Ed25519ph = 2,
}
private const long M28L = 0x0FFFFFFFL;
private const long M32L = 0xFFFFFFFFL;
private const int PointBytes = 32;
private const int ScalarUints = 8;
private const int ScalarBytes = ScalarUints * 4;
public static readonly int PrehashSize = 64;
public static readonly int PublicKeySize = PointBytes;
public static readonly int SecretKeySize = 32;
public static readonly int SignatureSize = PointBytes + ScalarBytes;
private static readonly byte[] Dom2Prefix = Strings.ToByteArray("SigEd25519 no Ed25519 collisions");
private static readonly uint[] P = { 0xFFFFFFEDU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0x7FFFFFFFU };
private static readonly uint[] L = { 0x5CF5D3EDU, 0x5812631AU, 0xA2F79CD6U, 0x14DEF9DEU, 0x00000000U, 0x00000000U, 0x00000000U, 0x10000000U };
private const int L0 = unchecked((int)0xFCF5D3ED); // L0:26/--
private const int L1 = 0x012631A6; // L1:24/22
private const int L2 = 0x079CD658; // L2:27/--
private const int L3 = unchecked((int)0xFF9DEA2F); // L3:23/--
private const int L4 = 0x000014DF; // L4:12/11
private static readonly int[] B_x = { 0x0325D51A, 0x018B5823, 0x007B2C95, 0x0304A92D, 0x00D2598E, 0x01D6DC5C,
0x01388C7F, 0x013FEC0A, 0x029E6B72, 0x0042D26D };
private static readonly int[] B_y = { 0x02666658, 0x01999999, 0x00666666, 0x03333333, 0x00CCCCCC, 0x02666666,
0x01999999, 0x00666666, 0x03333333, 0x00CCCCCC, };
private static readonly int[] C_d = { 0x035978A3, 0x02D37284, 0x018AB75E, 0x026A0A0E, 0x0000E014, 0x0379E898,
0x01D01E5D, 0x01E738CC, 0x03715B7F, 0x00A406D9 };
private static readonly int[] C_d2 = { 0x02B2F159, 0x01A6E509, 0x01156EBD, 0x00D4141D, 0x0001C029, 0x02F3D130,
0x03A03CBB, 0x01CE7198, 0x02E2B6FF, 0x00480DB3 };
private static readonly int[] C_d4 = { 0x0165E2B2, 0x034DCA13, 0x002ADD7A, 0x01A8283B, 0x00038052, 0x01E7A260,
0x03407977, 0x019CE331, 0x01C56DFF, 0x00901B67 };
private const int WnafWidthBase = 7;
private const int PrecompBlocks = 8;
private const int PrecompTeeth = 4;
private const int PrecompSpacing = 8;
private const int PrecompPoints = 1 << (PrecompTeeth - 1);
private const int PrecompMask = PrecompPoints - 1;
private static readonly object precompLock = new object();
// TODO[ed25519] Convert to PointPrecomp
private static PointExt[] precompBaseTable = null;
private static int[] precompBase = null;
private class PointAccum
{
internal int[] x = X25519Field.Create();
internal int[] y = X25519Field.Create();
internal int[] z = X25519Field.Create();
internal int[] u = X25519Field.Create();
internal int[] v = X25519Field.Create();
}
private class PointExt
{
internal int[] x = X25519Field.Create();
internal int[] y = X25519Field.Create();
internal int[] z = X25519Field.Create();
internal int[] t = X25519Field.Create();
}
private class PointPrecomp
{
internal int[] ypx_h = X25519Field.Create();
internal int[] ymx_h = X25519Field.Create();
internal int[] xyd = X25519Field.Create();
}
private static byte[] CalculateS(byte[] r, byte[] k, byte[] s)
{
uint[] t = new uint[ScalarUints * 2]; DecodeScalar(r, 0, t);
uint[] u = new uint[ScalarUints]; DecodeScalar(k, 0, u);
uint[] v = new uint[ScalarUints]; DecodeScalar(s, 0, v);
Nat256.MulAddTo(u, v, t);
byte[] result = new byte[ScalarBytes * 2];
for (int i = 0; i < t.Length; ++i)
{
Encode32(t[i], result, i * 4);
}
return ReduceScalar(result);
}
private static bool CheckContextVar(byte[] ctx, byte phflag)
{
return ctx == null && phflag == 0x00
|| ctx != null && ctx.Length < 256;
}
private static int CheckPoint(int[] x, int[] y)
{
int[] t = X25519Field.Create();
int[] u = X25519Field.Create();
int[] v = X25519Field.Create();
X25519Field.Sqr(x, u);
X25519Field.Sqr(y, v);
X25519Field.Mul(u, v, t);
X25519Field.Sub(v, u, v);
X25519Field.Mul(t, C_d, t);
X25519Field.AddOne(t);
X25519Field.Sub(t, v, t);
X25519Field.Normalize(t);
return X25519Field.IsZero(t);
}
private static int CheckPoint(int[] x, int[] y, int[] z)
{
int[] t = X25519Field.Create();
int[] u = X25519Field.Create();
int[] v = X25519Field.Create();
int[] w = X25519Field.Create();
X25519Field.Sqr(x, u);
X25519Field.Sqr(y, v);
X25519Field.Sqr(z, w);
X25519Field.Mul(u, v, t);
X25519Field.Sub(v, u, v);
X25519Field.Mul(v, w, v);
X25519Field.Sqr(w, w);
X25519Field.Mul(t, C_d, t);
X25519Field.Add(t, w, t);
X25519Field.Sub(t, v, t);
X25519Field.Normalize(t);
return X25519Field.IsZero(t);
}
private static bool CheckPointVar(byte[] p)
{
uint[] t = new uint[8];
Decode32(p, 0, t, 0, 8);
t[7] &= 0x7FFFFFFFU;
return !Nat256.Gte(t, P);
}
private static bool CheckScalarVar(byte[] s)
{
uint[] n = new uint[ScalarUints];
DecodeScalar(s, 0, n);
return !Nat256.Gte(n, L);
}
private static IDigest CreateDigest()
{
return new Sha512Digest();
}
public static IDigest CreatePrehash()
{
return CreateDigest();
}
private static uint Decode24(byte[] bs, int off)
{
uint n = bs[off];
n |= (uint)bs[++off] << 8;
n |= (uint)bs[++off] << 16;
return n;
}
private static uint Decode32(byte[] bs, int off)
{
uint n = bs[off];
n |= (uint)bs[++off] << 8;
n |= (uint)bs[++off] << 16;
n |= (uint)bs[++off] << 24;
return n;
}
private static void Decode32(byte[] bs, int bsOff, uint[] n, int nOff, int nLen)
{
for (int i = 0; i < nLen; ++i)
{
n[nOff + i] = Decode32(bs, bsOff + i * 4);
}
}
private static bool DecodePointVar(byte[] p, int pOff, bool negate, PointExt r)
{
byte[] py = Arrays.CopyOfRange(p, pOff, pOff + PointBytes);
if (!CheckPointVar(py))
return false;
int x_0 = (py[PointBytes - 1] & 0x80) >> 7;
py[PointBytes - 1] &= 0x7F;
X25519Field.Decode(py, 0, r.y);
int[] u = X25519Field.Create();
int[] v = X25519Field.Create();
X25519Field.Sqr(r.y, u);
X25519Field.Mul(C_d, u, v);
X25519Field.SubOne(u);
X25519Field.AddOne(v);
if (!X25519Field.SqrtRatioVar(u, v, r.x))
return false;
X25519Field.Normalize(r.x);
if (x_0 == 1 && X25519Field.IsZeroVar(r.x))
return false;
if (negate ^ (x_0 != (r.x[0] & 1)))
{
X25519Field.Negate(r.x, r.x);
}
PointExtendXY(r);
return true;
}
private static void DecodeScalar(byte[] k, int kOff, uint[] n)
{
Decode32(k, kOff, n, 0, ScalarUints);
}
private static void Dom2(IDigest d, byte phflag, byte[] ctx)
{
if (ctx != null)
{
d.BlockUpdate(Dom2Prefix, 0, Dom2Prefix.Length);
d.Update(phflag);
d.Update((byte)ctx.Length);
d.BlockUpdate(ctx, 0, ctx.Length);
}
}
private static void Encode24(uint n, byte[] bs, int off)
{
bs[off] = (byte)(n);
bs[++off] = (byte)(n >> 8);
bs[++off] = (byte)(n >> 16);
}
private static void Encode32(uint n, byte[] bs, int off)
{
bs[off] = (byte)(n);
bs[++off] = (byte)(n >> 8);
bs[++off] = (byte)(n >> 16);
bs[++off] = (byte)(n >> 24);
}
private static void Encode56(ulong n, byte[] bs, int off)
{
Encode32((uint)n, bs, off);
Encode24((uint)(n >> 32), bs, off + 4);
}
private static int EncodePoint(PointAccum p, byte[] r, int rOff)
{
int[] x = X25519Field.Create();
int[] y = X25519Field.Create();
X25519Field.Inv(p.z, y);
X25519Field.Mul(p.x, y, x);
X25519Field.Mul(p.y, y, y);
X25519Field.Normalize(x);
X25519Field.Normalize(y);
int result = CheckPoint(x, y);
X25519Field.Encode(y, r, rOff);
r[rOff + PointBytes - 1] |= (byte)((x[0] & 1) << 7);
return result;
}
public static void GeneratePrivateKey(SecureRandom random, byte[] k)
{
random.NextBytes(k);
}
public static void GeneratePublicKey(byte[] sk, int skOff, byte[] pk, int pkOff)
{
IDigest d = CreateDigest();
byte[] h = new byte[d.GetDigestSize()];
d.BlockUpdate(sk, skOff, SecretKeySize);
d.DoFinal(h, 0);
byte[] s = new byte[ScalarBytes];
PruneScalar(h, 0, s);
ScalarMultBaseEncoded(s, pk, pkOff);
}
private static sbyte[] GetWnaf(uint[] n, int width)
{
Debug.Assert(n[ScalarUints - 1] >> 28 == 0);
uint[] t = new uint[ScalarUints * 2];
{
uint c = 0;
int tPos = t.Length, i = ScalarUints;
while (--i >= 0)
{
uint next = n[i];
t[--tPos] = (next >> 16) | (c << 16);
t[--tPos] = c = next;
}
}
sbyte[] ws = new sbyte[253];
uint pow2 = 1U << width;
uint mask = pow2 - 1U;
uint sign = pow2 >> 1;
uint carry = 0U;
int j = 0;
for (int i = 0; i < t.Length; ++i, j -= 16)
{
uint word = t[i];
while (j < 16)
{
uint word16 = word >> j;
uint bit = word16 & 1U;
if (bit == carry)
{
++j;
continue;
}
uint digit = (word16 & mask) + carry;
carry = digit & sign;
digit -= (carry << 1);
carry >>= (width - 1);
ws[(i << 4) + j] = (sbyte)digit;
j += width;
}
}
Debug.Assert(carry == 0);
return ws;
}
private static void ImplSign(IDigest d, byte[] h, byte[] s, byte[] pk, int pkOff, byte[] ctx, byte phflag,
byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
{
Dom2(d, phflag, ctx);
d.BlockUpdate(h, ScalarBytes, ScalarBytes);
d.BlockUpdate(m, mOff, mLen);
d.DoFinal(h, 0);
byte[] r = ReduceScalar(h);
byte[] R = new byte[PointBytes];
ScalarMultBaseEncoded(r, R, 0);
Dom2(d, phflag, ctx);
d.BlockUpdate(R, 0, PointBytes);
d.BlockUpdate(pk, pkOff, PointBytes);
d.BlockUpdate(m, mOff, mLen);
d.DoFinal(h, 0);
byte[] k = ReduceScalar(h);
byte[] S = CalculateS(r, k, s);
Array.Copy(R, 0, sig, sigOff, PointBytes);
Array.Copy(S, 0, sig, sigOff + PointBytes, ScalarBytes);
}
private static void ImplSign(byte[] sk, int skOff, byte[] ctx, byte phflag, byte[] m, int mOff, int mLen,
byte[] sig, int sigOff)
{
if (!CheckContextVar(ctx, phflag))
throw new ArgumentException("ctx");
IDigest d = CreateDigest();
byte[] h = new byte[d.GetDigestSize()];
d.BlockUpdate(sk, skOff, SecretKeySize);
d.DoFinal(h, 0);
byte[] s = new byte[ScalarBytes];
PruneScalar(h, 0, s);
byte[] pk = new byte[PointBytes];
ScalarMultBaseEncoded(s, pk, 0);
ImplSign(d, h, s, pk, 0, ctx, phflag, m, mOff, mLen, sig, sigOff);
}
private static void ImplSign(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, byte phflag,
byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
{
if (!CheckContextVar(ctx, phflag))
throw new ArgumentException("ctx");
IDigest d = CreateDigest();
byte[] h = new byte[d.GetDigestSize()];
d.BlockUpdate(sk, skOff, SecretKeySize);
d.DoFinal(h, 0);
byte[] s = new byte[ScalarBytes];
PruneScalar(h, 0, s);
ImplSign(d, h, s, pk, pkOff, ctx, phflag, m, mOff, mLen, sig, sigOff);
}
private static bool ImplVerify(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, byte phflag,
byte[] m, int mOff, int mLen)
{
if (!CheckContextVar(ctx, phflag))
throw new ArgumentException("ctx");
byte[] R = Arrays.CopyOfRange(sig, sigOff, sigOff + PointBytes);
byte[] S = Arrays.CopyOfRange(sig, sigOff + PointBytes, sigOff + SignatureSize);
if (!CheckPointVar(R))
return false;
if (!CheckScalarVar(S))
return false;
PointExt pA = new PointExt();
if (!DecodePointVar(pk, pkOff, true, pA))
return false;
IDigest d = CreateDigest();
byte[] h = new byte[d.GetDigestSize()];
Dom2(d, phflag, ctx);
d.BlockUpdate(R, 0, PointBytes);
d.BlockUpdate(pk, pkOff, PointBytes);
d.BlockUpdate(m, mOff, mLen);
d.DoFinal(h, 0);
byte[] k = ReduceScalar(h);
uint[] nS = new uint[ScalarUints];
DecodeScalar(S, 0, nS);
uint[] nA = new uint[ScalarUints];
DecodeScalar(k, 0, nA);
PointAccum pR = new PointAccum();
ScalarMultStrausVar(nS, nA, pA, pR);
byte[] check = new byte[PointBytes];
return 0 != EncodePoint(pR, check, 0) && Arrays.AreEqual(check, R);
}
private static void PointAddVar(bool negate, PointExt p, PointAccum r)
{
int[] A = X25519Field.Create();
int[] B = X25519Field.Create();
int[] C = X25519Field.Create();
int[] D = X25519Field.Create();
int[] E = r.u;
int[] F = X25519Field.Create();
int[] G = X25519Field.Create();
int[] H = r.v;
int[] c, d, f, g;
if (negate)
{
c = D; d = C; f = G; g = F;
}
else
{
c = C; d = D; f = F; g = G;
}
X25519Field.Apm(r.y, r.x, B, A);
X25519Field.Apm(p.y, p.x, d, c);
X25519Field.Mul(A, C, A);
X25519Field.Mul(B, D, B);
X25519Field.Mul(r.u, r.v, C);
X25519Field.Mul(C, p.t, C);
X25519Field.Mul(C, C_d2, C);
X25519Field.Mul(r.z, p.z, D);
X25519Field.Add(D, D, D);
X25519Field.Apm(B, A, H, E);
X25519Field.Apm(D, C, g, f);
X25519Field.Carry(g);
X25519Field.Mul(E, F, r.x);
X25519Field.Mul(G, H, r.y);
X25519Field.Mul(F, G, r.z);
}
private static void PointAddVar(bool negate, PointExt p, PointExt q, PointExt r)
{
int[] A = X25519Field.Create();
int[] B = X25519Field.Create();
int[] C = X25519Field.Create();
int[] D = X25519Field.Create();
int[] E = X25519Field.Create();
int[] F = X25519Field.Create();
int[] G = X25519Field.Create();
int[] H = X25519Field.Create();
int[] c, d, f, g;
if (negate)
{
c = D; d = C; f = G; g = F;
}
else
{
c = C; d = D; f = F; g = G;
}
X25519Field.Apm(p.y, p.x, B, A);
X25519Field.Apm(q.y, q.x, d, c);
X25519Field.Mul(A, C, A);
X25519Field.Mul(B, D, B);
X25519Field.Mul(p.t, q.t, C);
X25519Field.Mul(C, C_d2, C);
X25519Field.Mul(p.z, q.z, D);
X25519Field.Add(D, D, D);
X25519Field.Apm(B, A, H, E);
X25519Field.Apm(D, C, g, f);
X25519Field.Carry(g);
X25519Field.Mul(E, F, r.x);
X25519Field.Mul(G, H, r.y);
X25519Field.Mul(F, G, r.z);
X25519Field.Mul(E, H, r.t);
}
private static void PointAddPrecomp(PointPrecomp p, PointAccum r)
{
int[] A = X25519Field.Create();
int[] B = X25519Field.Create();
int[] C = X25519Field.Create();
int[] E = r.u;
int[] F = X25519Field.Create();
int[] G = X25519Field.Create();
int[] H = r.v;
X25519Field.Apm(r.y, r.x, B, A);
X25519Field.Mul(A, p.ymx_h, A);
X25519Field.Mul(B, p.ypx_h, B);
X25519Field.Mul(r.u, r.v, C);
X25519Field.Mul(C, p.xyd, C);
X25519Field.Apm(B, A, H, E);
X25519Field.Apm(r.z, C, G, F);
X25519Field.Carry(G);
X25519Field.Mul(E, F, r.x);
X25519Field.Mul(G, H, r.y);
X25519Field.Mul(F, G, r.z);
}
private static PointExt PointCopy(PointAccum p)
{
PointExt r = new PointExt();
X25519Field.Copy(p.x, 0, r.x, 0);
X25519Field.Copy(p.y, 0, r.y, 0);
X25519Field.Copy(p.z, 0, r.z, 0);
X25519Field.Mul(p.u, p.v, r.t);
return r;
}
private static PointExt PointCopy(PointExt p)
{
PointExt r = new PointExt();
X25519Field.Copy(p.x, 0, r.x, 0);
X25519Field.Copy(p.y, 0, r.y, 0);
X25519Field.Copy(p.z, 0, r.z, 0);
X25519Field.Copy(p.t, 0, r.t, 0);
return r;
}
private static void PointDouble(PointAccum r)
{
int[] A = X25519Field.Create();
int[] B = X25519Field.Create();
int[] C = X25519Field.Create();
int[] E = r.u;
int[] F = X25519Field.Create();
int[] G = X25519Field.Create();
int[] H = r.v;
X25519Field.Sqr(r.x, A);
X25519Field.Sqr(r.y, B);
X25519Field.Sqr(r.z, C);
X25519Field.Add(C, C, C);
X25519Field.Apm(A, B, H, G);
X25519Field.Add(r.x, r.y, E);
X25519Field.Sqr(E, E);
X25519Field.Sub(H, E, E);
X25519Field.Add(C, G, F);
X25519Field.Carry(F);
X25519Field.Mul(E, F, r.x);
X25519Field.Mul(G, H, r.y);
X25519Field.Mul(F, G, r.z);
}
private static void PointExtendXY(PointAccum p)
{
X25519Field.One(p.z);
X25519Field.Copy(p.x, 0, p.u, 0);
X25519Field.Copy(p.y, 0, p.v, 0);
}
private static void PointExtendXY(PointExt p)
{
X25519Field.One(p.z);
X25519Field.Mul(p.x, p.y, p.t);
}
private static void PointLookup(int block, int index, PointPrecomp p)
{
Debug.Assert(0 <= block && block < PrecompBlocks);
Debug.Assert(0 <= index && index < PrecompPoints);
int off = block * PrecompPoints * 3 * X25519Field.Size;
for (int i = 0; i < PrecompPoints; ++i)
{
int cond = ((i ^ index) - 1) >> 31;
X25519Field.CMov(cond, precompBase, off, p.ypx_h, 0); off += X25519Field.Size;
X25519Field.CMov(cond, precompBase, off, p.ymx_h, 0); off += X25519Field.Size;
X25519Field.CMov(cond, precompBase, off, p.xyd, 0); off += X25519Field.Size;
}
}
private static PointExt[] PointPrecompVar(PointExt p, int count)
{
Debug.Assert(count > 0);
PointExt d = new PointExt();
PointAddVar(false, p, p, d);
PointExt[] table = new PointExt[count];
table[0] = PointCopy(p);
for (int i = 1; i < count; ++i)
{
PointAddVar(false, table[i - 1], d, table[i] = new PointExt());
}
return table;
}
private static void PointSetNeutral(PointAccum p)
{
X25519Field.Zero(p.x);
X25519Field.One(p.y);
X25519Field.One(p.z);
X25519Field.Zero(p.u);
X25519Field.One(p.v);
}
private static void PointSetNeutral(PointExt p)
{
X25519Field.Zero(p.x);
X25519Field.One(p.y);
X25519Field.One(p.z);
X25519Field.Zero(p.t);
}
public static void Precompute()
{
lock (precompLock)
{
if (precompBase != null)
return;
// Precomputed table for the base point in verification ladder
{
PointExt b = new PointExt();
X25519Field.Copy(B_x, 0, b.x, 0);
X25519Field.Copy(B_y, 0, b.y, 0);
PointExtendXY(b);
precompBaseTable = PointPrecompVar(b, 1 << (WnafWidthBase - 2));
}
PointAccum p = new PointAccum();
X25519Field.Copy(B_x, 0, p.x, 0);
X25519Field.Copy(B_y, 0, p.y, 0);
PointExtendXY(p);
precompBase = new int[PrecompBlocks * PrecompPoints * 3 * X25519Field.Size];
int off = 0;
for (int b = 0; b < PrecompBlocks; ++b)
{
PointExt[] ds = new PointExt[PrecompTeeth];
PointExt sum = new PointExt();
PointSetNeutral(sum);
for (int t = 0; t < PrecompTeeth; ++t)
{
PointExt q = PointCopy(p);
PointAddVar(true, sum, q, sum);
PointDouble(p);
ds[t] = PointCopy(p);
if (b + t != PrecompBlocks + PrecompTeeth - 2)
{
for (int s = 1; s < PrecompSpacing; ++s)
{
PointDouble(p);
}
}
}
PointExt[] points = new PointExt[PrecompPoints];
int k = 0;
points[k++] = sum;
for (int t = 0; t < (PrecompTeeth - 1); ++t)
{
int size = 1 << t;
for (int j = 0; j < size; ++j, ++k)
{
PointAddVar(false, points[k - size], ds[t], points[k] = new PointExt());
}
}
Debug.Assert(k == PrecompPoints);
for (int i = 0; i < PrecompPoints; ++i)
{
PointExt q = points[i];
int[] x = X25519Field.Create();
int[] y = X25519Field.Create();
X25519Field.Add(q.z, q.z, x);
// TODO[ed25519] Batch inversion
X25519Field.Inv(x, y);
X25519Field.Mul(q.x, y, x);
X25519Field.Mul(q.y, y, y);
PointPrecomp r = new PointPrecomp();
X25519Field.Apm(y, x, r.ypx_h, r.ymx_h);
X25519Field.Mul(x, y, r.xyd);
X25519Field.Mul(r.xyd, C_d4, r.xyd);
X25519Field.Normalize(r.ypx_h);
X25519Field.Normalize(r.ymx_h);
//X25519Field.Normalize(r.xyd);
X25519Field.Copy(r.ypx_h, 0, precompBase, off); off += X25519Field.Size;
X25519Field.Copy(r.ymx_h, 0, precompBase, off); off += X25519Field.Size;
X25519Field.Copy(r.xyd, 0, precompBase, off); off += X25519Field.Size;
}
}
Debug.Assert(off == precompBase.Length);
}
}
private static void PruneScalar(byte[] n, int nOff, byte[] r)
{
Array.Copy(n, nOff, r, 0, ScalarBytes);
r[0] &= 0xF8;
r[ScalarBytes - 1] &= 0x7F;
r[ScalarBytes - 1] |= 0x40;
}
private static byte[] ReduceScalar(byte[] n)
{
long x00 = Decode32(n, 0) & M32L; // x00:32/--
long x01 = (Decode24(n, 4) << 4) & M32L; // x01:28/--
long x02 = Decode32(n, 7) & M32L; // x02:32/--
long x03 = (Decode24(n, 11) << 4) & M32L; // x03:28/--
long x04 = Decode32(n, 14) & M32L; // x04:32/--
long x05 = (Decode24(n, 18) << 4) & M32L; // x05:28/--
long x06 = Decode32(n, 21) & M32L; // x06:32/--
long x07 = (Decode24(n, 25) << 4) & M32L; // x07:28/--
long x08 = Decode32(n, 28) & M32L; // x08:32/--
long x09 = (Decode24(n, 32) << 4) & M32L; // x09:28/--
long x10 = Decode32(n, 35) & M32L; // x10:32/--
long x11 = (Decode24(n, 39) << 4) & M32L; // x11:28/--
long x12 = Decode32(n, 42) & M32L; // x12:32/--
long x13 = (Decode24(n, 46) << 4) & M32L; // x13:28/--
long x14 = Decode32(n, 49) & M32L; // x14:32/--
long x15 = (Decode24(n, 53) << 4) & M32L; // x15:28/--
long x16 = Decode32(n, 56) & M32L; // x16:32/--
long x17 = (Decode24(n, 60) << 4) & M32L; // x17:28/--
long x18 = n[63] & 0xFFL; // x18:08/--
long t;
//x18 += (x17 >> 28); x17 &= M28L;
x09 -= x18 * L0; // x09:34/28
x10 -= x18 * L1; // x10:33/30
x11 -= x18 * L2; // x11:35/28
x12 -= x18 * L3; // x12:32/31
x13 -= x18 * L4; // x13:28/21
x17 += (x16 >> 28); x16 &= M28L; // x17:28/--, x16:28/--
x08 -= x17 * L0; // x08:54/32
x09 -= x17 * L1; // x09:52/51
x10 -= x17 * L2; // x10:55/34
x11 -= x17 * L3; // x11:51/36
x12 -= x17 * L4; // x12:41/--
//x16 += (x15 >> 28); x15 &= M28L;
x07 -= x16 * L0; // x07:54/28
x08 -= x16 * L1; // x08:54/53
x09 -= x16 * L2; // x09:55/53
x10 -= x16 * L3; // x10:55/52
x11 -= x16 * L4; // x11:51/41
x15 += (x14 >> 28); x14 &= M28L; // x15:28/--, x14:28/--
x06 -= x15 * L0; // x06:54/32
x07 -= x15 * L1; // x07:54/53
x08 -= x15 * L2; // x08:56/--
x09 -= x15 * L3; // x09:55/54
x10 -= x15 * L4; // x10:55/53
//x14 += (x13 >> 28); x13 &= M28L;
x05 -= x14 * L0; // x05:54/28
x06 -= x14 * L1; // x06:54/53
x07 -= x14 * L2; // x07:56/--
x08 -= x14 * L3; // x08:56/51
x09 -= x14 * L4; // x09:56/--
x13 += (x12 >> 28); x12 &= M28L; // x13:28/22, x12:28/--
x04 -= x13 * L0; // x04:54/49
x05 -= x13 * L1; // x05:54/53
x06 -= x13 * L2; // x06:56/--
x07 -= x13 * L3; // x07:56/52
x08 -= x13 * L4; // x08:56/52
x12 += (x11 >> 28); x11 &= M28L; // x12:28/24, x11:28/--
x03 -= x12 * L0; // x03:54/49
x04 -= x12 * L1; // x04:54/51
x05 -= x12 * L2; // x05:56/--
x06 -= x12 * L3; // x06:56/52
x07 -= x12 * L4; // x07:56/53
x11 += (x10 >> 28); x10 &= M28L; // x11:29/--, x10:28/--
x02 -= x11 * L0; // x02:55/32
x03 -= x11 * L1; // x03:55/--
x04 -= x11 * L2; // x04:56/55
x05 -= x11 * L3; // x05:56/52
x06 -= x11 * L4; // x06:56/53
x10 += (x09 >> 28); x09 &= M28L; // x10:29/--, x09:28/--
x01 -= x10 * L0; // x01:55/28
x02 -= x10 * L1; // x02:55/54
x03 -= x10 * L2; // x03:56/55
x04 -= x10 * L3; // x04:57/--
x05 -= x10 * L4; // x05:56/53
x08 += (x07 >> 28); x07 &= M28L; // x08:56/53, x07:28/--
x09 += (x08 >> 28); x08 &= M28L; // x09:29/25, x08:28/--
t = (x08 >> 27) & 1L;
x09 += t; // x09:29/26
x00 -= x09 * L0; // x00:55/53
x01 -= x09 * L1; // x01:55/54
x02 -= x09 * L2; // x02:57/--
x03 -= x09 * L3; // x03:57/--
x04 -= x09 * L4; // x04:57/42
x01 += (x00 >> 28); x00 &= M28L;
x02 += (x01 >> 28); x01 &= M28L;
x03 += (x02 >> 28); x02 &= M28L;
x04 += (x03 >> 28); x03 &= M28L;
x05 += (x04 >> 28); x04 &= M28L;
x06 += (x05 >> 28); x05 &= M28L;
x07 += (x06 >> 28); x06 &= M28L;
x08 += (x07 >> 28); x07 &= M28L;
x09 = (x08 >> 28); x08 &= M28L;
x09 -= t;
Debug.Assert(x09 == 0L || x09 == -1L);
x00 += x09 & L0;
x01 += x09 & L1;
x02 += x09 & L2;
x03 += x09 & L3;
x04 += x09 & L4;
x01 += (x00 >> 28); x00 &= M28L;
x02 += (x01 >> 28); x01 &= M28L;
x03 += (x02 >> 28); x02 &= M28L;
x04 += (x03 >> 28); x03 &= M28L;
x05 += (x04 >> 28); x04 &= M28L;
x06 += (x05 >> 28); x05 &= M28L;
x07 += (x06 >> 28); x06 &= M28L;
x08 += (x07 >> 28); x07 &= M28L;
byte[] r = new byte[ScalarBytes];
Encode56((ulong)(x00 | (x01 << 28)), r, 0);
Encode56((ulong)(x02 | (x03 << 28)), r, 7);
Encode56((ulong)(x04 | (x05 << 28)), r, 14);
Encode56((ulong)(x06 | (x07 << 28)), r, 21);
Encode32((uint)x08, r, 28);
return r;
}
private static void ScalarMultBase(byte[] k, PointAccum r)
{
Precompute();
PointSetNeutral(r);
uint[] n = new uint[ScalarUints];
DecodeScalar(k, 0, n);
// Recode the scalar into signed-digit form, then group comb bits in each block
{
uint c1 = Nat.CAdd(ScalarUints, ~(int)n[0] & 1, n, L, n); Debug.Assert(c1 == 0);
uint c2 = Nat.ShiftDownBit(ScalarUints, n, 1U); Debug.Assert(c2 == (1U << 31));
for (int i = 0; i < ScalarUints; ++i)
{
n[i] = Interleave.Shuffle2(n[i]);
}
}
PointPrecomp p = new PointPrecomp();
int cOff = (PrecompSpacing - 1) * PrecompTeeth;
for (; ; )
{
for (int b = 0; b < PrecompBlocks; ++b)
{
uint w = n[b] >> cOff;
int sign = (int)(w >> (PrecompTeeth - 1)) & 1;
int abs = ((int)w ^ -sign) & PrecompMask;
Debug.Assert(sign == 0 || sign == 1);
Debug.Assert(0 <= abs && abs < PrecompPoints);
PointLookup(b, abs, p);
X25519Field.CSwap(sign, p.ypx_h, p.ymx_h);
X25519Field.CNegate(sign, p.xyd);
PointAddPrecomp(p, r);
}
if ((cOff -= PrecompTeeth) < 0)
break;
PointDouble(r);
}
}
private static void ScalarMultBaseEncoded(byte[] k, byte[] r, int rOff)
{
PointAccum p = new PointAccum();
ScalarMultBase(k, p);
if (0 == EncodePoint(p, r, rOff))
throw new InvalidOperationException();
}
internal static void ScalarMultBaseYZ(byte[] k, int kOff, int[] y, int[] z)
{
byte[] n = new byte[ScalarBytes];
PruneScalar(k, kOff, n);
PointAccum p = new PointAccum();
ScalarMultBase(n, p);
if (0 == CheckPoint(p.x, p.y, p.z))
throw new InvalidOperationException();
X25519Field.Copy(p.y, 0, y, 0);
X25519Field.Copy(p.z, 0, z, 0);
}
private static void ScalarMultStrausVar(uint[] nb, uint[] np, PointExt p, PointAccum r)
{
Precompute();
int width = 5;
sbyte[] ws_b = GetWnaf(nb, WnafWidthBase);
sbyte[] ws_p = GetWnaf(np, width);
PointExt[] tp = PointPrecompVar(p, 1 << (width - 2));
PointSetNeutral(r);
for (int bit = 252;;)
{
int wb = ws_b[bit];
if (wb != 0)
{
int sign = wb >> 31;
int index = (wb ^ sign) >> 1;
PointAddVar((sign != 0), precompBaseTable[index], r);
}
int wp = ws_p[bit];
if (wp != 0)
{
int sign = wp >> 31;
int index = (wp ^ sign) >> 1;
PointAddVar((sign != 0), tp[index], r);
}
if (--bit < 0)
break;
PointDouble(r);
}
}
public static void Sign(byte[] sk, int skOff, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
{
byte[] ctx = null;
byte phflag = 0x00;
ImplSign(sk, skOff, ctx, phflag, m, mOff, mLen, sig, sigOff);
}
public static void Sign(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
{
byte[] ctx = null;
byte phflag = 0x00;
ImplSign(sk, skOff, pk, pkOff, ctx, phflag, m, mOff, mLen, sig, sigOff);
}
public static void Sign(byte[] sk, int skOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
{
byte phflag = 0x00;
ImplSign(sk, skOff, ctx, phflag, m, mOff, mLen, sig, sigOff);
}
public static void Sign(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
{
byte phflag = 0x00;
ImplSign(sk, skOff, pk, pkOff, ctx, phflag, m, mOff, mLen, sig, sigOff);
}
public static void SignPrehash(byte[] sk, int skOff, byte[] ctx, byte[] ph, int phOff, byte[] sig, int sigOff)
{
byte phflag = 0x01;
ImplSign(sk, skOff, ctx, phflag, ph, phOff, PrehashSize, sig, sigOff);
}
public static void SignPrehash(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, byte[] ph, int phOff, byte[] sig, int sigOff)
{
byte phflag = 0x01;
ImplSign(sk, skOff, pk, pkOff, ctx, phflag, ph, phOff, PrehashSize, sig, sigOff);
}
public static void SignPrehash(byte[] sk, int skOff, byte[] ctx, IDigest ph, byte[] sig, int sigOff)
{
byte[] m = new byte[PrehashSize];
if (PrehashSize != ph.DoFinal(m, 0))
throw new ArgumentException("ph");
byte phflag = 0x01;
ImplSign(sk, skOff, ctx, phflag, m, 0, m.Length, sig, sigOff);
}
public static void SignPrehash(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, IDigest ph, byte[] sig, int sigOff)
{
byte[] m = new byte[PrehashSize];
if (PrehashSize != ph.DoFinal(m, 0))
throw new ArgumentException("ph");
byte phflag = 0x01;
ImplSign(sk, skOff, pk, pkOff, ctx, phflag, m, 0, m.Length, sig, sigOff);
}
public static bool Verify(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] m, int mOff, int mLen)
{
byte[] ctx = null;
byte phflag = 0x00;
return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, m, mOff, mLen);
}
public static bool Verify(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen)
{
byte phflag = 0x00;
return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, m, mOff, mLen);
}
public static bool VerifyPrehash(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, byte[] ph, int phOff)
{
byte phflag = 0x01;
return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, ph, phOff, PrehashSize);
}
public static bool VerifyPrehash(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, IDigest ph)
{
byte[] m = new byte[PrehashSize];
if (PrehashSize != ph.DoFinal(m, 0))
throw new ArgumentException("ph");
byte phflag = 0x01;
return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, m, 0, m.Length);
}
}
}
#pragma warning restore
#endif