diff options
Diffstat (limited to 'crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs b/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs new file mode 100644 index 000000000..669c73bd2 --- /dev/null +++ b/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs @@ -0,0 +1,213 @@ +using System; + +using Org.BouncyCastle.Math.Raw; +using Org.BouncyCastle.Utilities; + +namespace Org.BouncyCastle.Math.EC.Custom.GM +{ + internal class SM2P256V1FieldElement + : ECFieldElement + { + public static readonly BigInteger Q = SM2P256V1Curve.q; + + protected internal readonly uint[] x; + + public SM2P256V1FieldElement(BigInteger x) + { + if (x == null || x.SignValue < 0 || x.CompareTo(Q) >= 0) + throw new ArgumentException("value invalid for SM2P256V1FieldElement", "x"); + + this.x = SM2P256V1Field.FromBigInteger(x); + } + + public SM2P256V1FieldElement() + { + this.x = Nat256.Create(); + } + + protected internal SM2P256V1FieldElement(uint[] x) + { + this.x = x; + } + + public override bool IsZero + { + get { return Nat256.IsZero(x); } + } + + public override bool IsOne + { + get { return Nat256.IsOne(x); } + } + + public override bool TestBitZero() + { + return Nat256.GetBit(x, 0) == 1; + } + + public override BigInteger ToBigInteger() + { + return Nat256.ToBigInteger(x); + } + + public override string FieldName + { + get { return "SM2P256V1Field"; } + } + + public override int FieldSize + { + get { return Q.BitLength; } + } + + public override ECFieldElement Add(ECFieldElement b) + { + uint[] z = Nat256.Create(); + SM2P256V1Field.Add(x, ((SM2P256V1FieldElement)b).x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement AddOne() + { + uint[] z = Nat256.Create(); + SM2P256V1Field.AddOne(x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement Subtract(ECFieldElement b) + { + uint[] z = Nat256.Create(); + SM2P256V1Field.Subtract(x, ((SM2P256V1FieldElement)b).x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement Multiply(ECFieldElement b) + { + uint[] z = Nat256.Create(); + SM2P256V1Field.Multiply(x, ((SM2P256V1FieldElement)b).x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement Divide(ECFieldElement b) + { + //return Multiply(b.Invert()); + uint[] z = Nat256.Create(); + Mod.Invert(SM2P256V1Field.P, ((SM2P256V1FieldElement)b).x, z); + SM2P256V1Field.Multiply(z, x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement Negate() + { + uint[] z = Nat256.Create(); + SM2P256V1Field.Negate(x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement Square() + { + uint[] z = Nat256.Create(); + SM2P256V1Field.Square(x, z); + return new SM2P256V1FieldElement(z); + } + + public override ECFieldElement Invert() + { + //return new SM2P256V1FieldElement(ToBigInteger().ModInverse(Q)); + uint[] z = Nat256.Create(); + Mod.Invert(SM2P256V1Field.P, x, z); + return new SM2P256V1FieldElement(z); + } + + /** + * return a sqrt root - the routine verifies that the calculation returns the right value - if + * none exists it returns null. + */ + public override ECFieldElement Sqrt() + { + /* + * Raise this element to the exponent 2^254 - 2^222 - 2^94 + 2^62 + * + * Breaking up the exponent's binary representation into "repunits", we get: + * { 31 1s } { 1 0s } { 128 1s } { 31 0s } { 1 1s } { 62 0s} + * + * We use an addition chain for the beginning: [1], 2, 3, 6, 12, [24], 30, [31] + */ + + uint[] x1 = this.x; + if (Nat256.IsZero(x1) || Nat256.IsOne(x1)) + { + return this; + } + + uint[] x2 = Nat256.Create(); + SM2P256V1Field.Square(x1, x2); + SM2P256V1Field.Multiply(x2, x1, x2); + uint[] x3 = x2; + SM2P256V1Field.Square(x2, x3); + SM2P256V1Field.Multiply(x3, x1, x3); + uint[] x6 = Nat256.Create(); + SM2P256V1Field.SquareN(x3, 3, x6); + SM2P256V1Field.Multiply(x6, x3, x6); + uint[] x12 = x3; + SM2P256V1Field.SquareN(x6, 6, x12); + SM2P256V1Field.Multiply(x12, x6, x12); + uint[] x24 = Nat256.Create(); + SM2P256V1Field.SquareN(x12, 12, x24); + SM2P256V1Field.Multiply(x24, x12, x24); + uint[] x30 = x12; + SM2P256V1Field.SquareN(x24, 6, x30); + SM2P256V1Field.Multiply(x30, x6, x30); + uint[] x31 = x6; + SM2P256V1Field.Square(x30, x31); + SM2P256V1Field.Multiply(x31, x1, x31); + + uint[] t1 = x31; + SM2P256V1Field.Square(x31, t1); + + uint[] x32 = x12; + SM2P256V1Field.Multiply(t1, x1, x32); + + SM2P256V1Field.SquareN(t1, 32, t1); + SM2P256V1Field.Multiply(t1, x32, t1); + + uint[] t2 = x24; + SM2P256V1Field.SquareN(t1, 32, t2); + SM2P256V1Field.Multiply(t2, x1, t2); + SM2P256V1Field.SquareN(t2, 32, t2); + SM2P256V1Field.Multiply(t2, t1, t2); + SM2P256V1Field.SquareN(t2, 32, t2); + SM2P256V1Field.Multiply(t2, x32, t2); + SM2P256V1Field.SquareN(t2, 32, t2); + SM2P256V1Field.Multiply(t2, x1, t2); + SM2P256V1Field.SquareN(t2, 62, t1); + SM2P256V1Field.Square(t1, t2); + + return Nat256.Eq(x1, t2) ? new SM2P256V1FieldElement(t1) : null; + } + + public override bool Equals(object obj) + { + return Equals(obj as SM2P256V1FieldElement); + } + + public override bool Equals(ECFieldElement other) + { + return Equals(other as SM2P256V1FieldElement); + } + + public virtual bool Equals(SM2P256V1FieldElement other) + { + if (this == other) + return true; + if (null == other) + return false; + return Nat256.Eq(x, other.x); + } + + public override int GetHashCode() + { + return Q.GetHashCode() ^ Arrays.GetHashCode(x, 0, 8); + } + } +} |