DERPrintableString.java

package org.apache.commons.ssl.asn1;

import java.io.IOException;

/** DER PrintableString object. */
public class DERPrintableString
    extends ASN1Object
    implements DERString {
    String string;

    /**
     * return a printable string from the passed in object.
     *
     * @throws IllegalArgumentException if the object cannot be converted.
     */
    public static DERPrintableString getInstance(
        Object obj) {
        if (obj == null || obj instanceof DERPrintableString) {
            return (DERPrintableString) obj;
        }

        if (obj instanceof ASN1OctetString) {
            return new DERPrintableString(((ASN1OctetString) obj).getOctets());
        }

        if (obj instanceof ASN1TaggedObject) {
            return getInstance(((ASN1TaggedObject) obj).getObject());
        }

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

    /**
     * return a Printable 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.
     * @throws IllegalArgumentException if the tagged object cannot
     *                                  be converted.
     */
    public static DERPrintableString getInstance(
        ASN1TaggedObject obj,
        boolean explicit) {
        return getInstance(obj.getObject());
    }

    /** basic constructor - byte encoded string. */
    public DERPrintableString(
        byte[] string) {
        char[] cs = new char[string.length];

        for (int i = 0; i != cs.length; i++) {
            cs[i] = (char) (string[i] & 0xff);
        }

        this.string = new String(cs);
    }

    /** basic constructor - this does not validate the string */
    public DERPrintableString(
        String string) {
        this(string, false);
    }

    /**
     * Constructor with optional validation.
     *
     * @param string   the base string to wrap.
     * @param validate whether or not to check the string.
     * @throws IllegalArgumentException if validate is true and the string
     *                                  contains characters that should not be in a PrintableString.
     */
    public DERPrintableString(
        String string,
        boolean validate) {
        if (validate && !isPrintableString(string)) {
            throw new IllegalArgumentException("string contains illegal characters");
        }

        this.string = string;
    }

    public String getString() {
        return string;
    }

    public byte[] getOctets() {
        char[] cs = string.toCharArray();
        byte[] bs = new byte[cs.length];

        for (int i = 0; i != cs.length; i++) {
            bs[i] = (byte) cs[i];
        }

        return bs;
    }

    void encode(
        DEROutputStream out)
        throws IOException {
        out.writeEncoded(PRINTABLE_STRING, this.getOctets());
    }

    public int hashCode() {
        return this.getString().hashCode();
    }

    boolean asn1Equals(
        DERObject o) {
        if (!(o instanceof DERPrintableString)) {
            return false;
        }

        DERPrintableString s = (DERPrintableString) o;

        return this.getString().equals(s.getString());
    }

    public String toString() {
        return string;
    }

    /**
     * return true if the passed in String can be represented without
     * loss as a PrintableString, false otherwise.
     *
     * @return true if in printable set, false otherwise.
     */
    public static boolean isPrintableString(
        String str) {
        for (int i = str.length() - 1; i >= 0; i--) {
            char ch = str.charAt(i);

            if (ch > 0x007f) {
                return false;
            }

            if ('a' <= ch && ch <= 'z') {
                continue;
            }

            if ('A' <= ch && ch <= 'Z') {
                continue;
            }

            if ('0' <= ch && ch <= '9') {
                continue;
            }

            switch (ch) {
                case ' ':
                case '\'':
                case '(':
                case ')':
                case '+':
                case '-':
                case '.':
                case ':':
                case '=':
                case '?':
                case '/':
                case ',':
                    continue;
            }

            return false;
        }

        return true;
    }
}