diff options
Diffstat (limited to 'core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP384R1FieldElement.java')
-rw-r--r-- | core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP384R1FieldElement.java | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP384R1FieldElement.java b/core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP384R1FieldElement.java new file mode 100644 index 00000000..3203bda9 --- /dev/null +++ b/core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP384R1FieldElement.java @@ -0,0 +1,211 @@ +package org.spongycastle.math.ec.custom.sec; + +import java.math.BigInteger; + +import org.spongycastle.math.ec.ECFieldElement; +import org.spongycastle.math.raw.Mod; +import org.spongycastle.math.raw.Nat; +import org.spongycastle.util.Arrays; + +public class SecP384R1FieldElement extends ECFieldElement +{ + public static final BigInteger Q = SecP384R1Curve.q; + + protected int[] x; + + public SecP384R1FieldElement(BigInteger x) + { + if (x == null || x.signum() < 0 || x.compareTo(Q) >= 0) + { + throw new IllegalArgumentException("x value invalid for SecP384R1FieldElement"); + } + + this.x = SecP384R1Field.fromBigInteger(x); + } + + public SecP384R1FieldElement() + { + this.x = Nat.create(12); + } + + protected SecP384R1FieldElement(int[] x) + { + this.x = x; + } + + public boolean isZero() + { + return Nat.isZero(12, x); + } + + public boolean isOne() + { + return Nat.isOne(12, x); + } + + public boolean testBitZero() + { + return Nat.getBit(x, 0) == 1; + } + + public BigInteger toBigInteger() + { + return Nat.toBigInteger(12, x); + } + + public String getFieldName() + { + return "SecP384R1Field"; + } + + public int getFieldSize() + { + return Q.bitLength(); + } + + public ECFieldElement add(ECFieldElement b) + { + int[] z = Nat.create(12); + SecP384R1Field.add(x, ((SecP384R1FieldElement)b).x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement addOne() + { + int[] z = Nat.create(12); + SecP384R1Field.addOne(x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement subtract(ECFieldElement b) + { + int[] z = Nat.create(12); + SecP384R1Field.subtract(x, ((SecP384R1FieldElement)b).x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement multiply(ECFieldElement b) + { + int[] z = Nat.create(12); + SecP384R1Field.multiply(x, ((SecP384R1FieldElement)b).x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement divide(ECFieldElement b) + { +// return multiply(b.invert()); + int[] z = Nat.create(12); + Mod.invert(SecP384R1Field.P, ((SecP384R1FieldElement)b).x, z); + SecP384R1Field.multiply(z, x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement negate() + { + int[] z = Nat.create(12); + SecP384R1Field.negate(x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement square() + { + int[] z = Nat.create(12); + SecP384R1Field.square(x, z); + return new SecP384R1FieldElement(z); + } + + public ECFieldElement invert() + { +// return new SecP384R1FieldElement(toBigInteger().modInverse(Q)); + int[] z = Nat.create(12); + Mod.invert(SecP384R1Field.P, x, z); + return new SecP384R1FieldElement(z); + } + + /** + * return a sqrt root - the routine verifies that the calculation returns the right value - if + * none exists it returns null. + */ + public ECFieldElement sqrt() + { + // Raise this element to the exponent 2^382 - 2^126 - 2^94 + 2^30 + + int[] x1 = this.x; + if (Nat.isZero(12, x1) || Nat.isOne(12, x1)) + { + return this; + } + + int[] t1 = Nat.create(12); + int[] t2 = Nat.create(12); + int[] t3 = Nat.create(12); + int[] t4 = Nat.create(12); + + SecP384R1Field.square(x1, t1); + SecP384R1Field.multiply(t1, x1, t1); + + SecP384R1Field.squareN(t1, 2, t2); + SecP384R1Field.multiply(t2, t1, t2); + + SecP384R1Field.square(t2, t2); + SecP384R1Field.multiply(t2, x1, t2); + + SecP384R1Field.squareN(t2, 5, t3); + SecP384R1Field.multiply(t3, t2, t3); + + SecP384R1Field.squareN(t3, 5, t4); + SecP384R1Field.multiply(t4, t2, t4); + + SecP384R1Field.squareN(t4, 15, t2); + SecP384R1Field.multiply(t2, t4, t2); + + SecP384R1Field.squareN(t2, 2, t3); + SecP384R1Field.multiply(t1, t3, t1); + + SecP384R1Field.squareN(t3, 28, t3); + SecP384R1Field.multiply(t2, t3, t2); + + SecP384R1Field.squareN(t2, 60, t3); + SecP384R1Field.multiply(t3, t2, t3); + + int[] r = t2; + + SecP384R1Field.squareN(t3, 120, r); + SecP384R1Field.multiply(r, t3, r); + + SecP384R1Field.squareN(r, 15, r); + SecP384R1Field.multiply(r, t4, r); + + SecP384R1Field.squareN(r, 33, r); + SecP384R1Field.multiply(r, t1, r); + + SecP384R1Field.squareN(r, 64, r); + SecP384R1Field.multiply(r, x1, r); + + SecP384R1Field.squareN(r, 30, t1); + SecP384R1Field.square(t1, t2); + + return Nat.eq(12, x1, t2) ? new SecP384R1FieldElement(t1) : null; + } + + public boolean equals(Object other) + { + if (other == this) + { + return true; + } + + if (!(other instanceof SecP384R1FieldElement)) + { + return false; + } + + SecP384R1FieldElement o = (SecP384R1FieldElement)other; + return Nat.eq(12, x, o.x); + } + + public int hashCode() + { + return Q.hashCode() ^ Arrays.hashCode(x, 0, 12); + } +} |