DSTU4145PointEncoder.smali

.class public abstract Lorg/spongycastle/asn1/ua/DSTU4145PointEncoder;
.super Ljava/lang/Object;
.source "DSTU4145PointEncoder.java"


# direct methods
.method public constructor <init>()V
    .registers 1

    .prologue
    .line 15
    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    return-void
.end method

.method public static decodePoint(Lorg/spongycastle/math/ec/ECCurve;[B)Lorg/spongycastle/math/ec/ECPoint;
    .registers 7

    .prologue
    .line 120
    array-length v0, p1

    add-int/lit8 v0, v0, -0x1

    aget-byte v0, p1, v0

    and-int/lit8 v0, v0, 0x1

    int-to-long v0, v0

    invoke-static {v0, v1}, Ljava/math/BigInteger;->valueOf(J)Ljava/math/BigInteger;

    move-result-object v0

    invoke-virtual {p0, v0}, Lorg/spongycastle/math/ec/ECCurve;->fromBigInteger(Ljava/math/BigInteger;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v3

    .line 122
    new-instance v0, Ljava/math/BigInteger;

    const/4 v1, 0x1

    invoke-direct {v0, v1, p1}, Ljava/math/BigInteger;-><init>(I[B)V

    invoke-virtual {p0, v0}, Lorg/spongycastle/math/ec/ECCurve;->fromBigInteger(Ljava/math/BigInteger;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

    .line 123
    invoke-static {v0}, Lorg/spongycastle/asn1/ua/DSTU4145PointEncoder;->trace(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {p0}, Lorg/spongycastle/math/ec/ECCurve;->getA()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v2

    invoke-virtual {v1, v2}, Ljava/lang/Object;->equals(Ljava/lang/Object;)Z

    move-result v1

    if-nez v1, :cond_2c

    .line 125
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->addOne()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

    .line 128
    :cond_2c
    const/4 v2, 0x0

    .line 129
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->isZero()Z

    move-result v1

    if-eqz v1, :cond_45

    .line 131
    invoke-virtual {p0}, Lorg/spongycastle/math/ec/ECCurve;->getB()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->sqrt()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 147
    :goto_3b
    if-nez v1, :cond_7a

    .line 149
    new-instance v0, Ljava/lang/IllegalArgumentException;

    const-string v1, "Invalid point compression"

    invoke-direct {v0, v1}, Ljava/lang/IllegalArgumentException;-><init>(Ljava/lang/String;)V

    throw v0

    .line 135
    :cond_45
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->square()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->invert()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {p0}, Lorg/spongycastle/math/ec/ECCurve;->getB()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v4

    invoke-virtual {v1, v4}, Lorg/spongycastle/math/ec/ECFieldElement;->multiply(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {p0}, Lorg/spongycastle/math/ec/ECCurve;->getA()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v4

    invoke-virtual {v1, v4}, Lorg/spongycastle/math/ec/ECFieldElement;->add(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {v1, v0}, Lorg/spongycastle/math/ec/ECFieldElement;->add(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 136
    invoke-static {p0, v1}, Lorg/spongycastle/asn1/ua/DSTU4145PointEncoder;->solveQuadraticEquation(Lorg/spongycastle/math/ec/ECCurve;Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 137
    if-eqz v1, :cond_87

    .line 139
    invoke-static {v1}, Lorg/spongycastle/asn1/ua/DSTU4145PointEncoder;->trace(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v2

    invoke-virtual {v2, v3}, Ljava/lang/Object;->equals(Ljava/lang/Object;)Z

    move-result v2

    if-nez v2, :cond_75

    .line 141
    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->addOne()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 143
    :cond_75
    invoke-virtual {v0, v1}, Lorg/spongycastle/math/ec/ECFieldElement;->multiply(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    goto :goto_3b

    .line 152
    :cond_7a
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->toBigInteger()Ljava/math/BigInteger;

    move-result-object v0

    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->toBigInteger()Ljava/math/BigInteger;

    move-result-object v1

    invoke-virtual {p0, v0, v1}, Lorg/spongycastle/math/ec/ECCurve;->createPoint(Ljava/math/BigInteger;Ljava/math/BigInteger;)Lorg/spongycastle/math/ec/ECPoint;

    move-result-object v0

    return-object v0

    :cond_87
    move-object v1, v2

    goto :goto_3b
.end method

.method public static encodePoint(Lorg/spongycastle/math/ec/ECPoint;)[B
    .registers 5

    .prologue
    .line 85
    invoke-virtual {p0}, Lorg/spongycastle/math/ec/ECPoint;->normalize()Lorg/spongycastle/math/ec/ECPoint;

    move-result-object v0

    .line 87
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECPoint;->getAffineXCoord()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 89
    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->getEncoded()[B

    move-result-object v2

    .line 91
    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->isZero()Z

    move-result v3

    if-nez v3, :cond_2e

    .line 93
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECPoint;->getAffineYCoord()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

    invoke-virtual {v0, v1}, Lorg/spongycastle/math/ec/ECFieldElement;->divide(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

    .line 94
    invoke-static {v0}, Lorg/spongycastle/asn1/ua/DSTU4145PointEncoder;->trace(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->isOne()Z

    move-result v0

    if-eqz v0, :cond_2f

    .line 96
    array-length v0, v2

    add-int/lit8 v0, v0, -0x1

    aget-byte v1, v2, v0

    or-int/lit8 v1, v1, 0x1

    int-to-byte v1, v1

    aput-byte v1, v2, v0

    .line 104
    :cond_2e
    :goto_2e
    return-object v2

    .line 100
    :cond_2f
    array-length v0, v2

    add-int/lit8 v0, v0, -0x1

    aget-byte v1, v2, v0

    and-int/lit16 v1, v1, 0xfe

    int-to-byte v1, v1

    aput-byte v1, v2, v0

    goto :goto_2e
.end method

.method private static solveQuadraticEquation(Lorg/spongycastle/math/ec/ECCurve;Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;
    .registers 10

    .prologue
    .line 37
    invoke-virtual {p1}, Lorg/spongycastle/math/ec/ECFieldElement;->isZero()Z

    move-result v0

    if-eqz v0, :cond_7

    .line 68
    :goto_6
    return-object p1

    .line 42
    :cond_7
    sget-object v0, Lorg/spongycastle/math/ec/ECConstants;->ZERO:Ljava/math/BigInteger;

    invoke-virtual {p0, v0}, Lorg/spongycastle/math/ec/ECCurve;->fromBigInteger(Ljava/math/BigInteger;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v3

    .line 47
    new-instance v5, Ljava/util/Random;

    invoke-direct {v5}, Ljava/util/Random;-><init>()V

    .line 48
    invoke-virtual {p1}, Lorg/spongycastle/math/ec/ECFieldElement;->getFieldSize()I

    move-result v6

    .line 51
    :cond_16
    new-instance v0, Ljava/math/BigInteger;

    invoke-direct {v0, v6, v5}, Ljava/math/BigInteger;-><init>(ILjava/util/Random;)V

    invoke-virtual {p0, v0}, Lorg/spongycastle/math/ec/ECCurve;->fromBigInteger(Ljava/math/BigInteger;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v7

    .line 54
    const/4 v0, 0x1

    move v1, v0

    move-object v2, p1

    move-object v0, v3

    :goto_23
    add-int/lit8 v4, v6, -0x1

    if-gt v1, v4, :cond_40

    .line 56
    invoke-virtual {v2}, Lorg/spongycastle/math/ec/ECFieldElement;->square()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v2

    .line 57
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->square()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

    invoke-virtual {v2, v7}, Lorg/spongycastle/math/ec/ECFieldElement;->multiply(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v4

    invoke-virtual {v0, v4}, Lorg/spongycastle/math/ec/ECFieldElement;->add(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v4

    .line 58
    invoke-virtual {v2, p1}, Lorg/spongycastle/math/ec/ECFieldElement;->add(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v2

    .line 54
    add-int/lit8 v0, v1, 0x1

    move v1, v0

    move-object v0, v4

    goto :goto_23

    .line 60
    :cond_40
    invoke-virtual {v2}, Lorg/spongycastle/math/ec/ECFieldElement;->isZero()Z

    move-result v1

    if-nez v1, :cond_48

    .line 62
    const/4 p1, 0x0

    goto :goto_6

    .line 64
    :cond_48
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECFieldElement;->square()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {v1, v0}, Lorg/spongycastle/math/ec/ECFieldElement;->add(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 66
    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->isZero()Z

    move-result v1

    if-nez v1, :cond_16

    move-object p1, v0

    .line 68
    goto :goto_6
.end method

.method private static trace(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;
    .registers 4

    .prologue
    .line 19
    .line 20
    const/4 v0, 0x1

    move-object v1, p0

    :goto_2
    invoke-virtual {p0}, Lorg/spongycastle/math/ec/ECFieldElement;->getFieldSize()I

    move-result v2

    if-ge v0, v2, :cond_13

    .line 22
    invoke-virtual {v1}, Lorg/spongycastle/math/ec/ECFieldElement;->square()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    invoke-virtual {v1, p0}, Lorg/spongycastle/math/ec/ECFieldElement;->add(Lorg/spongycastle/math/ec/ECFieldElement;)Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v1

    .line 20
    add-int/lit8 v0, v0, 0x1

    goto :goto_2

    .line 24
    :cond_13
    return-object v1
.end method