diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP224R1Curve.cs')
-rw-r--r-- | crypto/src/math/ec/custom/sec/SecP224R1Curve.cs | 63 |
1 files changed, 61 insertions, 2 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP224R1Curve.cs b/crypto/src/math/ec/custom/sec/SecP224R1Curve.cs index cda8781ff..ec34390aa 100644 --- a/crypto/src/math/ec/custom/sec/SecP224R1Curve.cs +++ b/crypto/src/math/ec/custom/sec/SecP224R1Curve.cs @@ -1,5 +1,6 @@ using System; +using Org.BouncyCastle.Math.Raw; using Org.BouncyCastle.Utilities.Encoders; namespace Org.BouncyCastle.Math.EC.Custom.Sec @@ -10,7 +11,8 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static readonly BigInteger q = new BigInteger(1, Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF000000000000000000000001")); - private const int SecP224R1_DEFAULT_COORDS = COORD_JACOBIAN; + private const int SECP224R1_DEFAULT_COORDS = COORD_JACOBIAN; + private const int SECP224R1_FE_INTS = 7; protected readonly SecP224R1Point m_infinity; @@ -26,7 +28,7 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec this.m_order = new BigInteger(1, Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFF16A2E0B8F03E13DD29455C5C2A3D")); this.m_cofactor = BigInteger.One; - this.m_coord = SecP224R1_DEFAULT_COORDS; + this.m_coord = SECP224R1_DEFAULT_COORDS; } protected override ECCurve CloneCurve() @@ -74,5 +76,62 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec { return new SecP224R1Point(this, x, y, zs, withCompression); } + + public override ECLookupTable CreateCacheSafeLookupTable(ECPoint[] points, int off, int len) + { + uint[] table = new uint[len * SECP224R1_FE_INTS * 2]; + { + int pos = 0; + for (int i = 0; i < len; ++i) + { + ECPoint p = points[off + i]; + Nat224.Copy(((SecP224R1FieldElement)p.RawXCoord).x, 0, table, pos); pos += SECP224R1_FE_INTS; + Nat224.Copy(((SecP224R1FieldElement)p.RawYCoord).x, 0, table, pos); pos += SECP224R1_FE_INTS; + } + } + + return new SecP224R1LookupTable(this, table, len); + } + + private class SecP224R1LookupTable + : ECLookupTable + { + private readonly SecP224R1Curve m_outer; + private readonly uint[] m_table; + private readonly int m_size; + + internal SecP224R1LookupTable(SecP224R1Curve outer, uint[] table, int size) + { + this.m_outer = outer; + this.m_table = table; + this.m_size = size; + } + + public virtual int Size + { + get { return m_size; } + } + + public virtual ECPoint Lookup(int index) + { + uint[] x = Nat224.Create(), y = Nat224.Create(); + int pos = 0; + + for (int i = 0; i < m_size; ++i) + { + uint MASK = (uint)(((i ^ index) - 1) >> 31); + + for (int j = 0; j < SECP224R1_FE_INTS; ++j) + { + x[j] ^= m_table[pos + j] & MASK; + y[j] ^= m_table[pos + SECP224R1_FE_INTS + j] & MASK; + } + + pos += (SECP224R1_FE_INTS * 2); + } + + return m_outer.CreateRawPoint(new SecP224R1FieldElement(x), new SecP224R1FieldElement(y), false); + } + } } } |