ECDHCBasicAgreement.smali

.class public Lorg/spongycastle/crypto/agreement/ECDHCBasicAgreement;
.super Ljava/lang/Object;
.source "ECDHCBasicAgreement.java"

# interfaces
.implements Lorg/spongycastle/crypto/BasicAgreement;


# instance fields
.field key:Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;


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

    .prologue
    .line 31
    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    return-void
.end method


# virtual methods
.method public calculateAgreement(Lorg/spongycastle/crypto/CipherParameters;)Ljava/math/BigInteger;
    .registers 5

    .prologue
    .line 50
    check-cast p1, Lorg/spongycastle/crypto/params/ECPublicKeyParameters;

    .line 51
    invoke-virtual {p1}, Lorg/spongycastle/crypto/params/ECPublicKeyParameters;->getParameters()Lorg/spongycastle/crypto/params/ECDomainParameters;

    move-result-object v0

    .line 53
    invoke-virtual {v0}, Lorg/spongycastle/crypto/params/ECDomainParameters;->getH()Ljava/math/BigInteger;

    move-result-object v1

    iget-object v2, p0, Lorg/spongycastle/crypto/agreement/ECDHCBasicAgreement;->key:Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;

    invoke-virtual {v2}, Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;->getD()Ljava/math/BigInteger;

    move-result-object v2

    invoke-virtual {v1, v2}, Ljava/math/BigInteger;->multiply(Ljava/math/BigInteger;)Ljava/math/BigInteger;

    move-result-object v1

    invoke-virtual {v0}, Lorg/spongycastle/crypto/params/ECDomainParameters;->getN()Ljava/math/BigInteger;

    move-result-object v0

    invoke-virtual {v1, v0}, Ljava/math/BigInteger;->mod(Ljava/math/BigInteger;)Ljava/math/BigInteger;

    move-result-object v0

    .line 55
    invoke-virtual {p1}, Lorg/spongycastle/crypto/params/ECPublicKeyParameters;->getQ()Lorg/spongycastle/math/ec/ECPoint;

    move-result-object v1

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

    move-result-object v0

    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECPoint;->normalize()Lorg/spongycastle/math/ec/ECPoint;

    move-result-object v0

    .line 57
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECPoint;->isInfinity()Z

    move-result v1

    if-eqz v1, :cond_36

    .line 59
    new-instance v0, Ljava/lang/IllegalStateException;

    const-string v1, "Infinity is not a valid agreement value for ECDHC"

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

    throw v0

    .line 62
    :cond_36
    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECPoint;->getAffineXCoord()Lorg/spongycastle/math/ec/ECFieldElement;

    move-result-object v0

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

    move-result-object v0

    return-object v0
.end method

.method public getFieldSize()I
    .registers 2

    .prologue
    .line 44
    iget-object v0, p0, Lorg/spongycastle/crypto/agreement/ECDHCBasicAgreement;->key:Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;

    invoke-virtual {v0}, Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;->getParameters()Lorg/spongycastle/crypto/params/ECDomainParameters;

    move-result-object v0

    invoke-virtual {v0}, Lorg/spongycastle/crypto/params/ECDomainParameters;->getCurve()Lorg/spongycastle/math/ec/ECCurve;

    move-result-object v0

    invoke-virtual {v0}, Lorg/spongycastle/math/ec/ECCurve;->getFieldSize()I

    move-result v0

    add-int/lit8 v0, v0, 0x7

    div-int/lit8 v0, v0, 0x8

    return v0
.end method

.method public init(Lorg/spongycastle/crypto/CipherParameters;)V
    .registers 2

    .prologue
    .line 39
    check-cast p1, Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;

    iput-object p1, p0, Lorg/spongycastle/crypto/agreement/ECDHCBasicAgreement;->key:Lorg/spongycastle/crypto/params/ECPrivateKeyParameters;

    .line 40
    return-void
.end method