universal/security/SecurityUtils.java

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package com.sun.enterprise.universal.security;

import java.security.SecureRandom;

/**
 * Created October 28, 2010
 * @author Byron Nevins
 */
public final class SecurityUtils {

    public static String getSecureRandomHexString(int numBytes) {
        SecureRandom random = new SecureRandom();
        byte[] bb = new byte[numBytes];
        random.nextBytes(bb);
        return toHexString(bb);
    }

    /**
     * No instances allowed.
     */
    private SecurityUtils() {
    }

    static private String toHexString(byte b) {
        String s = Integer.toHexString((int) b + 128);

        if (s.length() == 1)
            s = "0" + s;

        return s;
    }

    static private String toHexString(byte[] bb) {
        StringBuilder sb = new StringBuilder();

        for (byte b : bb)
            sb.append(toHexString(b));

        return sb.toString();
    }
}