diff options
Diffstat (limited to 'crypto/src/math/ec/rfc8032/Ed448.cs')
| -rw-r--r-- | crypto/src/math/ec/rfc8032/Ed448.cs | 232 |
1 files changed, 146 insertions, 86 deletions
diff --git a/crypto/src/math/ec/rfc8032/Ed448.cs b/crypto/src/math/ec/rfc8032/Ed448.cs index 52c215160..0e56b12a8 100644 --- a/crypto/src/math/ec/rfc8032/Ed448.cs +++ b/crypto/src/math/ec/rfc8032/Ed448.cs @@ -2,6 +2,7 @@ using System.Diagnostics; using System.Runtime.CompilerServices; +using Org.BouncyCastle.Crypto; using Org.BouncyCastle.Crypto.Digests; using Org.BouncyCastle.Math.EC.Rfc7748; using Org.BouncyCastle.Math.Raw; @@ -18,6 +19,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 private const int ScalarUints = 14; private const int ScalarBytes = ScalarUints * 4 + 1; + public static readonly int PrehashSize = 64; public static readonly int PublicKeySize = PointBytes; public static readonly int SecretKeySize = 57; public static readonly int SignatureSize = PointBytes + ScalarBytes; @@ -103,9 +105,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 private static bool CheckPointVar(byte[] p) { if ((p[PointBytes - 1] & 0x7F) != 0x00) - { return false; - } uint[] t = new uint[14]; Decode32(p, 0, t, 0, 14); @@ -115,15 +115,23 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 private static bool CheckScalarVar(byte[] s) { if (s[ScalarBytes - 1] != 0x00) - { return false; - } uint[] n = new uint[ScalarUints]; DecodeScalar(s, 0, n); return !Nat.Gte(ScalarUints, n, L); } + public static IXof CreatePrehash() + { + return CreateXof(); + } + + private static IXof CreateXof() + { + return new ShakeDigest(256); + } + private static uint Decode16(byte[] bs, int off) { uint n = bs[off]; @@ -160,9 +168,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 { 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; @@ -179,15 +185,11 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 X448Field.AddOne(v); if (!X448Field.SqrtRatioVar(u, v, r.x)) - { return false; - } X448Field.Normalize(r.x); if (x_0 == 1 && X448Field.IsZeroVar(r.x)) - { return false; - } if (negate ^ (x_0 != (r.x[0] & 1))) { @@ -205,7 +207,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 Decode32(k, kOff, n, 0, ScalarUints); } - private static void Dom4(ShakeDigest d, byte x, byte[] y) + private static void Dom4(IXof d, byte x, byte[] y) { d.BlockUpdate(Dom4Prefix, 0, Dom4Prefix.Length); d.Update(x); @@ -251,7 +253,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 public static void GeneratePublicKey(byte[] sk, int skOff, byte[] pk, int pkOff) { - ShakeDigest d = new ShakeDigest(256); + IXof d = CreateXof(); byte[] h = new byte[ScalarBytes * 2]; d.BlockUpdate(sk, skOff, SecretKeySize); @@ -317,10 +319,9 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 return ws; } - private static void ImplSign(ShakeDigest d, byte[] h, byte[] s, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff) + private static void ImplSign(IXof d, byte[] h, byte[] s, byte[] pk, int pkOff, byte[] ctx, byte phflag, + byte[] m, int mOff, int mLen, byte[] sig, int sigOff) { - byte phflag = 0x00; - Dom4(d, phflag, ctx); d.BlockUpdate(h, ScalarBytes, ScalarBytes); d.BlockUpdate(m, mOff, mLen); @@ -343,6 +344,90 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 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)) + throw new ArgumentException("ctx"); + + IXof d = CreateXof(); + byte[] h = new byte[ScalarBytes * 2]; + + d.BlockUpdate(sk, skOff, SecretKeySize); + d.DoFinal(h, 0, h.Length); + + 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)) + throw new ArgumentException("ctx"); + + IXof d = CreateXof(); + byte[] h = new byte[ScalarBytes * 2]; + + d.BlockUpdate(sk, skOff, SecretKeySize); + d.DoFinal(h, 0, h.Length); + + 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)) + 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; + + IXof d = CreateXof(); + byte[] h = new byte[ScalarBytes * 2]; + + Dom4(d, phflag, ctx); + d.BlockUpdate(R, 0, PointBytes); + d.BlockUpdate(pk, pkOff, PointBytes); + d.BlockUpdate(m, mOff, mLen); + d.DoFinal(h, 0, h.Length); + + byte[] k = ReduceScalar(h); + + uint[] nS = new uint[ScalarUints]; + DecodeScalar(S, 0, nS); + + uint[] nA = new uint[ScalarUints]; + DecodeScalar(k, 0, nA); + + PointExt pR = new PointExt(); + ScalarMultStraussVar(nS, nA, pA, pR); + + byte[] check = new byte[PointBytes]; + EncodePoint(pR, check, 0); + + return Arrays.AreEqual(check, R); + } + private static void PointAddVar(bool negate, PointExt p, PointExt r) { uint[] A = X448Field.Create(); @@ -505,9 +590,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 public static void Precompute() { if (precompBase != null) - { return; - } PointExt p = new PointExt(); X448Field.Copy(B_x, 0, p.x, 0); @@ -907,9 +990,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 } if (--cOff < 0) - { break; - } PointDouble(r); } @@ -962,9 +1043,7 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 } if (--bit < 0) - { break; - } PointDouble(r); } @@ -972,96 +1051,77 @@ namespace Org.BouncyCastle.Math.EC.Rfc8032 public static void Sign(byte[] sk, int skOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff) { - if (!CheckContextVar(ctx)) - { - throw new ArgumentException("ctx"); - } + byte phflag = 0x00; - ShakeDigest d = new ShakeDigest(256); - byte[] h = new byte[ScalarBytes * 2]; + ImplSign(sk, skOff, ctx, phflag, m, mOff, mLen, sig, sigOff); + } - d.BlockUpdate(sk, skOff, SecretKeySize); - d.DoFinal(h, 0, h.Length); + 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; - byte[] s = new byte[ScalarBytes]; - PruneScalar(h, 0, s); + ImplSign(sk, skOff, pk, pkOff, ctx, phflag, m, mOff, mLen, sig, sigOff); + } - byte[] pk = new byte[PointBytes]; - ScalarMultBaseEncoded(s, pk, 0); + public static void SignPrehash(byte[] sk, int skOff, byte[] ctx, byte[] ph, int phOff, byte[] sig, int sigOff) + { + byte phflag = 0x01; - ImplSign(d, h, s, pk, 0, ctx, m, mOff, mLen, sig, sigOff); + ImplSign(sk, skOff, ctx, phflag, ph, phOff, PrehashSize, 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) + public static void SignPrehash(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, byte[] ph, int phOff, byte[] sig, int sigOff) { - if (!CheckContextVar(ctx)) - { - throw new ArgumentException("ctx"); - } + byte phflag = 0x01; - ShakeDigest d = new ShakeDigest(256); - byte[] h = new byte[ScalarBytes * 2]; + ImplSign(sk, skOff, pk, pkOff, ctx, phflag, ph, phOff, PrehashSize, sig, sigOff); + } - d.BlockUpdate(sk, skOff, SecretKeySize); - d.DoFinal(h, 0, h.Length); + public static void SignPrehash(byte[] sk, int skOff, byte[] ctx, IXof ph, byte[] sig, int sigOff) + { + byte[] m = new byte[PrehashSize]; + if (PrehashSize != ph.DoFinal(m, 0, PrehashSize)) + throw new ArgumentException("ph"); - byte[] s = new byte[ScalarBytes]; - PruneScalar(h, 0, s); + byte phflag = 0x01; - ImplSign(d, h, s, pk, pkOff, ctx, m, mOff, mLen, sig, sigOff); + ImplSign(sk, skOff, ctx, phflag, m, 0, m.Length, sig, sigOff); } - public static bool Verify(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen) + public static void SignPrehash(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, IXof ph, byte[] sig, int sigOff) { - if (!CheckContextVar(ctx)) - { - throw new ArgumentException("ctx"); - } - - byte[] R = Arrays.CopyOfRange(sig, sigOff, sigOff + PointBytes); - byte[] S = Arrays.CopyOfRange(sig, sigOff + PointBytes, sigOff + SignatureSize); + byte[] m = new byte[PrehashSize]; + if (PrehashSize != ph.DoFinal(m, 0, PrehashSize)) + throw new ArgumentException("ph"); - if (!CheckPointVar(R)) - { - return false; - } - if (!CheckScalarVar(S)) - { - return false; - } + byte phflag = 0x01; - PointExt pA = new PointExt(); - if (!DecodePointVar(pk, pkOff, true, pA)) - { - return false; - } + 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[] ctx, byte[] m, int mOff, int mLen) + { byte phflag = 0x00; - ShakeDigest d = new ShakeDigest(256); - byte[] h = new byte[ScalarBytes * 2]; - - Dom4(d, phflag, ctx); - d.BlockUpdate(R, 0, PointBytes); - d.BlockUpdate(pk, pkOff, PointBytes); - d.BlockUpdate(m, mOff, mLen); - d.DoFinal(h, 0, h.Length); - - byte[] k = ReduceScalar(h); + return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, m, mOff, mLen); + } - uint[] nS = new uint[ScalarUints]; - DecodeScalar(S, 0, nS); + public static bool VerifyPrehash(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, byte[] ph, int phOff) + { + byte phflag = 0x01; - uint[] nA = new uint[ScalarUints]; - DecodeScalar(k, 0, nA); + return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, ph, phOff, PrehashSize); + } - PointExt pR = new PointExt(); - ScalarMultStraussVar(nS, nA, pA, pR); + public static bool VerifyPrehash(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, IXof ph) + { + byte[] m = new byte[PrehashSize]; + if (PrehashSize != ph.DoFinal(m, 0, PrehashSize)) + throw new ArgumentException("ph"); - byte[] check = new byte[PointBytes]; - EncodePoint(pR, check, 0); + byte phflag = 0x01; - return Arrays.AreEqual(check, R); + return ImplVerify(sig, sigOff, pk, pkOff, ctx, phflag, m, 0, m.Length); } } } |