HKDF.smali

.class public Lcom/avast/crypto/HKDF;
.super Ljava/lang/Object;


# instance fields
.field private final a:Ljavax/crypto/Mac;


# direct methods
.method public constructor <init>(Ljavax/crypto/Mac;)V
    .registers 3

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

    if-eqz p1, :cond_8

    iput-object p1, p0, Lcom/avast/crypto/HKDF;->a:Ljavax/crypto/Mac;

    return-void

    :cond_8
    new-instance p1, Ljava/lang/NullPointerException;

    const-string v0, "hmac"

    invoke-direct {p1, v0}, Ljava/lang/NullPointerException;-><init>(Ljava/lang/String;)V

    throw p1
.end method

.method static varargs c([B[[B)[B
    .registers 8

    array-length v0, p0

    const/4 v1, 0x0

    add-int/2addr v0, v1

    array-length v2, p1

    const/4 v3, 0x0

    :goto_5
    if-ge v3, v2, :cond_e

    aget-object v4, p1, v3

    array-length v4, v4

    add-int/2addr v0, v4

    add-int/lit8 v3, v3, 0x1

    goto :goto_5

    :cond_e
    new-array v0, v0, [B

    array-length v2, p0

    invoke-static {p0, v1, v0, v1, v2}, Ljava/lang/System;->arraycopy(Ljava/lang/Object;ILjava/lang/Object;II)V

    array-length p0, p1

    const/4 v3, 0x0

    :goto_16
    if-ge v3, p0, :cond_23

    aget-object v4, p1, v3

    array-length v5, v4

    invoke-static {v4, v1, v0, v2, v5}, Ljava/lang/System;->arraycopy(Ljava/lang/Object;ILjava/lang/Object;II)V

    array-length v4, v4

    add-int/2addr v2, v4

    add-int/lit8 v3, v3, 0x1

    goto :goto_16

    :cond_23
    return-object v0
.end method

.method private d([B)Ljava/security/Key;
    .registers 4

    array-length v0, p1

    if-nez v0, :cond_b

    iget-object p1, p0, Lcom/avast/crypto/HKDF;->a:Ljavax/crypto/Mac;

    invoke-virtual {p1}, Ljavax/crypto/Mac;->getMacLength()I

    move-result p1

    new-array p1, p1, [B

    :cond_b
    new-instance v0, Ljavax/crypto/spec/SecretKeySpec;

    iget-object v1, p0, Lcom/avast/crypto/HKDF;->a:Ljavax/crypto/Mac;

    invoke-virtual {v1}, Ljavax/crypto/Mac;->getAlgorithm()Ljava/lang/String;

    move-result-object v1

    invoke-direct {v0, p1, v1}, Ljavax/crypto/spec/SecretKeySpec;-><init>([BLjava/lang/String;)V

    return-object v0
.end method

.method private static e([BLjavax/crypto/Mac;)[B
    .registers 2

    invoke-virtual {p1, p0}, Ljavax/crypto/Mac;->update([B)V

    invoke-virtual {p1}, Ljavax/crypto/Mac;->doFinal()[B

    move-result-object p0

    invoke-virtual {p1}, Ljavax/crypto/Mac;->reset()V

    return-object p0
.end method

.method private static f(Ljava/lang/String;)[B
    .registers 6

    invoke-virtual {p0}, Ljava/lang/String;->length()I

    move-result v0

    rem-int/lit8 v0, v0, 0x2

    const/4 v1, 0x1

    if-ne v0, v1, :cond_1a

    new-instance v0, Ljava/lang/StringBuilder;

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

    const-string v1, "0"

    invoke-virtual {v0, v1}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;

    invoke-virtual {v0, p0}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;

    invoke-virtual {v0}, Ljava/lang/StringBuilder;->toString()Ljava/lang/String;

    move-result-object p0

    :cond_1a
    invoke-virtual {p0}, Ljava/lang/String;->length()I

    move-result v0

    div-int/lit8 v0, v0, 0x2

    new-array v1, v0, [B

    const/4 v2, 0x0

    :goto_23
    if-ge v2, v0, :cond_39

    mul-int/lit8 v3, v2, 0x2

    add-int/lit8 v4, v3, 0x2

    invoke-virtual {p0, v3, v4}, Ljava/lang/String;->substring(II)Ljava/lang/String;

    move-result-object v3

    const/16 v4, 0x10

    invoke-static {v3, v4}, Ljava/lang/Integer;->parseInt(Ljava/lang/String;I)I

    move-result v3

    int-to-byte v3, v3

    aput-byte v3, v1, v2

    add-int/lit8 v2, v2, 0x1

    goto :goto_23

    :cond_39
    return-object v1
.end method

.method private g([B)Ljavax/crypto/Mac;
    .registers 3
    .annotation system Ldalvik/annotation/Throws;
        value = {
            Ljava/security/NoSuchAlgorithmException;,
            Ljava/security/InvalidKeyException;
        }
    .end annotation

    iget-object v0, p0, Lcom/avast/crypto/HKDF;->a:Ljavax/crypto/Mac;

    invoke-direct {p0, p1}, Lcom/avast/crypto/HKDF;->d([B)Ljava/security/Key;

    move-result-object p1

    invoke-virtual {v0, p1}, Ljavax/crypto/Mac;->init(Ljava/security/Key;)V

    iget-object p1, p0, Lcom/avast/crypto/HKDF;->a:Ljavax/crypto/Mac;

    return-object p1
.end method


# virtual methods
.method public a([B[BI)[B
    .registers 12
    .annotation system Ldalvik/annotation/Throws;
        value = {
            Ljava/security/NoSuchAlgorithmException;,
            Ljava/security/InvalidKeyException;
        }
    .end annotation

    invoke-direct {p0, p1}, Lcom/avast/crypto/HKDF;->g([B)Ljavax/crypto/Mac;

    move-result-object p1

    const/4 v0, 0x0

    new-array v1, v0, [B

    new-array v2, v0, [B

    int-to-double v3, p3

    invoke-virtual {p1}, Ljavax/crypto/Mac;->getMacLength()I

    move-result v5

    int-to-double v5, v5

    div-double/2addr v3, v5

    invoke-static {v3, v4}, Ljava/lang/Math;->ceil(D)D

    move-result-wide v3

    double-to-int v3, v3

    const/4 v4, 0x0

    :goto_16
    if-ge v4, v3, :cond_3b

    const/4 v5, 0x2

    new-array v5, v5, [[B

    aput-object p2, v5, v0

    add-int/lit8 v4, v4, 0x1

    invoke-static {v4}, Ljava/lang/Integer;->toHexString(I)Ljava/lang/String;

    move-result-object v6

    invoke-static {v6}, Lcom/avast/crypto/HKDF;->f(Ljava/lang/String;)[B

    move-result-object v6

    const/4 v7, 0x1

    aput-object v6, v5, v7

    invoke-static {v1, v5}, Lcom/avast/crypto/HKDF;->c([B[[B)[B

    move-result-object v1

    invoke-static {v1, p1}, Lcom/avast/crypto/HKDF;->e([BLjavax/crypto/Mac;)[B

    move-result-object v1

    new-array v5, v7, [[B

    aput-object v1, v5, v0

    invoke-static {v2, v5}, Lcom/avast/crypto/HKDF;->c([B[[B)[B

    move-result-object v2

    goto :goto_16

    :cond_3b
    new-array p1, p3, [B

    invoke-static {v2, v0, p1, v0, p3}, Ljava/lang/System;->arraycopy(Ljava/lang/Object;ILjava/lang/Object;II)V

    return-object p1
.end method

.method public b([B[B)[B
    .registers 3
    .annotation system Ldalvik/annotation/Throws;
        value = {
            Ljava/security/NoSuchAlgorithmException;,
            Ljava/security/InvalidKeyException;
        }
    .end annotation

    invoke-direct {p0, p1}, Lcom/avast/crypto/HKDF;->g([B)Ljavax/crypto/Mac;

    move-result-object p1

    invoke-static {p2, p1}, Lcom/avast/crypto/HKDF;->e([BLjavax/crypto/Mac;)[B

    move-result-object p1

    return-object p1
.end method