org.bouncycastle.asn1.ASN1Boolean.java Source code

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Here is the source code for org.bouncycastle.asn1.ASN1Boolean.java

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package org.bouncycastle.asn1;

import java.io.IOException;

/**
 * Public facade of ASN.1 Boolean data.
 * <p>
 * Use following to place a new instance of ASN.1 Boolean in your data:
 * <ul>
 * <li> ASN1Boolean.TRUE literal</li>
 * <li> ASN1Boolean.FALSE literal</li>
 * <li> {@link ASN1Boolean#getInstance(boolean) ASN1Boolean.getInstance(boolean)}</li>
 * <li> {@link ASN1Boolean#getInstance(int) ASN1Boolean.getInstance(int)}</li>
 * </ul>
 */
public class ASN1Boolean extends ASN1Primitive {
    private static final byte FALSE_VALUE = 0x00;
    private static final byte TRUE_VALUE = (byte) 0xFF;

    public static final ASN1Boolean FALSE = new ASN1Boolean(FALSE_VALUE);
    public static final ASN1Boolean TRUE = new ASN1Boolean(TRUE_VALUE);

    private final byte value;

    /**
     * Return a boolean from the passed in object.
     *
     * @param obj an ASN1Boolean or an object that can be converted into one.
     * @exception IllegalArgumentException if the object cannot be converted.
     * @return an ASN1Boolean instance.
     */
    public static ASN1Boolean getInstance(Object obj) {
        if (obj == null || obj instanceof ASN1Boolean) {
            return (ASN1Boolean) obj;
        }

        if (obj instanceof byte[]) {
            byte[] enc = (byte[]) obj;
            try {
                return (ASN1Boolean) fromByteArray(enc);
            } catch (IOException e) {
                throw new IllegalArgumentException("failed to construct boolean from byte[]: " + e.getMessage());
            }
        }

        throw new IllegalArgumentException("illegal object in getInstance: " + obj.getClass().getName());
    }

    /**
     * Return an ASN1Boolean from the passed in boolean.
     * @param value true or false depending on the ASN1Boolean wanted.
     * @return an ASN1Boolean instance.
     */
    public static ASN1Boolean getInstance(boolean value) {
        return value ? TRUE : FALSE;
    }

    /**
     * Return an ASN1Boolean from the passed in value.
     * @param value non-zero (true) or zero (false) depending on the ASN1Boolean wanted.
     * @return an ASN1Boolean instance.
     */
    public static ASN1Boolean getInstance(int value) {
        return value != 0 ? TRUE : FALSE;
    }

    /**
     * Return a Boolean from a tagged object.
     *
     * @param obj the tagged object holding the object we want
     * @param explicit true if the object is meant to be explicitly
     *              tagged false otherwise.
     * @exception IllegalArgumentException if the tagged object cannot
     *               be converted.
     * @return an ASN1Boolean instance.
     */
    public static ASN1Boolean getInstance(ASN1TaggedObject obj, boolean explicit) {
        ASN1Primitive o = obj.getObject();

        if (explicit || o instanceof ASN1Boolean) {
            return getInstance(o);
        } else {
            return ASN1Boolean.fromOctetString(ASN1OctetString.getInstance(o).getOctets());
        }
    }

    private ASN1Boolean(byte value) {
        this.value = value;
    }

    public boolean isTrue() {
        return value != FALSE_VALUE;
    }

    boolean isConstructed() {
        return false;
    }

    int encodedLength() {
        return 3;
    }

    void encode(ASN1OutputStream out, boolean withTag) throws IOException {
        out.writeEncoded(withTag, BERTags.BOOLEAN, value);
    }

    boolean asn1Equals(ASN1Primitive other) {
        if (!(other instanceof ASN1Boolean)) {
            return false;
        }

        ASN1Boolean that = (ASN1Boolean) other;

        return this.isTrue() == that.isTrue();
    }

    public int hashCode() {
        return isTrue() ? 1 : 0;
    }

    ASN1Primitive toDERObject() {
        return isTrue() ? TRUE : FALSE;
    }

    public String toString() {
        return isTrue() ? "TRUE" : "FALSE";
    }

    static ASN1Boolean fromOctetString(byte[] value) {
        if (value.length != 1) {
            throw new IllegalArgumentException("BOOLEAN value should have 1 byte in it");
        }

        byte b = value[0];
        switch (b) {
        case FALSE_VALUE:
            return FALSE;
        case TRUE_VALUE:
            return TRUE;
        default:
            return new ASN1Boolean(b);
        }
    }
}