org.bouncycastle.asn1.DERBMPString.java Source code

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

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package org.bouncycastle.asn1;

import java.io.IOException;

import org.bouncycastle.util.Arrays;

/**
 * DER BMPString object encodes BMP (<i>Basic Multilingual Plane</i>) subset
 * (aka UCS-2) of UNICODE (ISO 10646) characters in codepoints 0 to 65535.
 * <p>
 * At ISO-10646:2011 the term "BMP" has been withdrawn, and replaced by
 * term "UCS-2".
 * </p>
 */
public class DERBMPString extends ASN1Primitive implements ASN1String {
    private final char[] string;

    /**
     * Return a BMP String from the given object.
     *
     * @param obj the object we want converted.
     * @exception IllegalArgumentException if the object cannot be converted.
     * @return a DERBMPString instance, or null.
     */
    public static DERBMPString getInstance(Object obj) {
        if (obj == null || obj instanceof DERBMPString) {
            return (DERBMPString) obj;
        }

        if (obj instanceof byte[]) {
            try {
                return (DERBMPString) fromByteArray((byte[]) obj);
            } catch (Exception e) {
                throw new IllegalArgumentException("encoding error in getInstance: " + e.toString());
            }
        }

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

    /**
     * Return a BMP String 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 a DERBMPString instance.
     */
    public static DERBMPString getInstance(ASN1TaggedObject obj, boolean explicit) {
        ASN1Primitive o = obj.getObject();

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

    /**
     * Basic constructor - byte encoded string.
     * @param string the encoded BMP STRING to wrap.
     */
    DERBMPString(byte[] string) {
        char[] cs = new char[string.length / 2];

        for (int i = 0; i != cs.length; i++) {
            cs[i] = (char) ((string[2 * i] << 8) | (string[2 * i + 1] & 0xff));
        }

        this.string = cs;
    }

    DERBMPString(char[] string) {
        this.string = string;
    }

    /**
     * Basic constructor
     * @param string a String to wrap as a BMP STRING.
     */
    public DERBMPString(String string) {
        this.string = string.toCharArray();
    }

    public String getString() {
        return new String(string);
    }

    public String toString() {
        return getString();
    }

    public int hashCode() {
        return Arrays.hashCode(string);
    }

    protected boolean asn1Equals(ASN1Primitive o) {
        if (!(o instanceof DERBMPString)) {
            return false;
        }

        DERBMPString s = (DERBMPString) o;

        return Arrays.areEqual(string, s.string);
    }

    boolean isConstructed() {
        return false;
    }

    int encodedLength() {
        return 1 + StreamUtil.calculateBodyLength(string.length * 2) + (string.length * 2);
    }

    void encode(ASN1OutputStream out, boolean withTag) throws IOException {
        int count = string.length;
        if (withTag) {
            out.write(BERTags.BMP_STRING);
        }
        out.writeLength(count * 2);

        byte[] buf = new byte[8];

        int i = 0, limit = count & -4;
        while (i < limit) {
            char c0 = string[i], c1 = string[i + 1], c2 = string[i + 2], c3 = string[i + 3];
            i += 4;

            buf[0] = (byte) (c0 >> 8);
            buf[1] = (byte) c0;
            buf[2] = (byte) (c1 >> 8);
            buf[3] = (byte) c1;
            buf[4] = (byte) (c2 >> 8);
            buf[5] = (byte) c2;
            buf[6] = (byte) (c3 >> 8);
            buf[7] = (byte) c3;

            out.write(buf, 0, 8);
        }
        if (i < count) {
            int bufPos = 0;
            do {
                char c0 = string[i];
                i += 1;

                buf[bufPos++] = (byte) (c0 >> 8);
                buf[bufPos++] = (byte) c0;
            } while (i < count);

            out.write(buf, 0, bufPos);
        }
    }
}