diff options
Diffstat (limited to 'crypto/src/math/ec/ECCurve.cs')
| -rw-r--r-- | crypto/src/math/ec/ECCurve.cs | 58 |
1 files changed, 49 insertions, 9 deletions
diff --git a/crypto/src/math/ec/ECCurve.cs b/crypto/src/math/ec/ECCurve.cs index 5b9b39c10..60fbc887a 100644 --- a/crypto/src/math/ec/ECCurve.cs +++ b/crypto/src/math/ec/ECCurve.cs @@ -521,7 +521,7 @@ namespace Org.BouncyCastle.Math.EC } private class DefaultLookupTable - : ECLookupTable + : AbstractECLookupTable { private readonly ECCurve m_outer; private readonly byte[] m_table; @@ -534,12 +534,12 @@ namespace Org.BouncyCastle.Math.EC this.m_size = size; } - public virtual int Size + public override int Size { get { return m_size; } } - public virtual ECPoint Lookup(int index) + public override ECPoint Lookup(int index) { int FE_BYTES = (m_outer.FieldSize + 7) / 8; byte[] x = new byte[FE_BYTES], y = new byte[FE_BYTES]; @@ -558,6 +558,26 @@ namespace Org.BouncyCastle.Math.EC pos += (FE_BYTES * 2); } + return CreatePoint(x, y); + } + + public override ECPoint LookupVar(int index) + { + int FE_BYTES = (m_outer.FieldSize + 7) / 8; + byte[] x = new byte[FE_BYTES], y = new byte[FE_BYTES]; + int pos = index * FE_BYTES * 2; + + for (int j = 0; j < FE_BYTES; ++j) + { + x[j] = m_table[pos + j]; + y[j] = m_table[pos + FE_BYTES + j]; + } + + return CreatePoint(x, y); + } + + private ECPoint CreatePoint(byte[] x, byte[] y) + { ECFieldElement X = m_outer.FromBigInteger(new BigInteger(1, x)); ECFieldElement Y = m_outer.FromBigInteger(new BigInteger(1, y)); return m_outer.CreateRawPoint(X, Y, false); @@ -1251,7 +1271,7 @@ namespace Org.BouncyCastle.Math.EC } private class DefaultF2mLookupTable - : ECLookupTable + : AbstractECLookupTable { private readonly F2mCurve m_outer; private readonly long[] m_table; @@ -1264,16 +1284,13 @@ namespace Org.BouncyCastle.Math.EC this.m_size = size; } - public virtual int Size + public override int Size { get { return m_size; } } - public virtual ECPoint Lookup(int index) + public override ECPoint Lookup(int index) { - int m = m_outer.m; - int[] ks = m_outer.IsTrinomial() ? new int[]{ m_outer.k1 } : new int[]{ m_outer.k1, m_outer.k2, m_outer.k3 }; - int FE_LONGS = (m_outer.m + 63) / 64; long[] x = new long[FE_LONGS], y = new long[FE_LONGS]; int pos = 0; @@ -1291,6 +1308,29 @@ namespace Org.BouncyCastle.Math.EC pos += (FE_LONGS * 2); } + return CreatePoint(x, y); + } + + public override ECPoint LookupVar(int index) + { + int FE_LONGS = (m_outer.m + 63) / 64; + long[] x = new long[FE_LONGS], y = new long[FE_LONGS]; + int pos = index * FE_LONGS * 2; + + for (int j = 0; j < FE_LONGS; ++j) + { + x[j] = m_table[pos + j]; + y[j] = m_table[pos + FE_LONGS + j]; + } + + return CreatePoint(x, y); + } + + private ECPoint CreatePoint(long[] x, long[] y) + { + int m = m_outer.m; + int[] ks = m_outer.IsTrinomial() ? new int[] { m_outer.k1 } : new int[] { m_outer.k1, m_outer.k2, m_outer.k3 }; + ECFieldElement X = new F2mFieldElement(m, ks, new LongArray(x)); ECFieldElement Y = new F2mFieldElement(m, ks, new LongArray(y)); return m_outer.CreateRawPoint(X, Y, false); |