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Liferay SAML OpenSAML Integration
/* See LICENSE for licensing and NOTICE for copyright. */
package org.cryptacular.bean;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.StandardCharsets;
import org.bouncycastle.crypto.generators.BCrypt;
import org.cryptacular.CryptoException;
import org.cryptacular.StreamException;
import org.cryptacular.codec.Base64Decoder;
import org.cryptacular.codec.Base64Encoder;
import org.cryptacular.codec.Decoder;
import org.cryptacular.codec.Encoder;
import org.cryptacular.util.ByteUtil;
/**
* {@link HashBean} implementation that uses the bcrypt algorithm for hashing. Hash strings of the following
* format are supported:
*
*
* $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
*
* where:
* n is an optional bcrypt algorithm version (typically "a" or "b")
* 4 ≤ cost ≤ 31
* x is 22 characters of encoded salt
* y is 31 characters of encoded hash bytes
*
*
* The encoding for salt and hash bytes is a variant of base-64 encoding without padding in the following alphabet:
*
*
* ./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
*
* @author Middleware Services
*/
public class BCryptHashBean implements HashBean
{
/** Custom base-64 alphabet. */
private static final String ALPHABET = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
/** BCrypt cost factor in the range [4, 31]. Default value is {@value}. */
private int cost = 12;
/** BCrypt version used when computing hashes. Default value is {@value}. */
private String version = "2b";
/** Creates a new instance. */
public BCryptHashBean() {}
/**
* Creates a new instance that uses the given cost factor when hashing.
*
* @param costFactor BCrypt cost in the range [4, 31].
*/
public BCryptHashBean(final int costFactor)
{
setCost(costFactor);
}
/**
* Sets the bcrypt cost factor.
*
* @param costFactor BCrypt cost in the range [4, 31].
*/
public void setCost(final int costFactor)
{
if (costFactor < 4 || costFactor > 31) {
throw new IllegalArgumentException("Cost must be in the range [4, 31].");
}
cost = costFactor;
}
/**
* Sets the bcrypt version.
*
* @param ver Bcrypt version, e.g. "2b"
*/
public void setVersion(final String ver)
{
if (!ver.startsWith("2") && ver.length() <= 2) {
throw new IllegalArgumentException("Invalid version: " + ver);
}
version = ver;
}
/**
* Compute a bcrypt hash of the form $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
* given a salt and a password.
* @param data A 2-element array containing salt and password. The salt may be encoded per the bcrypt standard
* or raw bytes.
*
* @return An encoded bcrypt hash, yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy in the specification above.
*
* @throws CryptoException on bcrypt algorithm errors.
*/
@Override
public String hash(final Object... data) throws CryptoException
{
if (data.length != 2) {
throw new IllegalArgumentException("Expected exactly two elements in data array but got " + data.length);
}
return encode(BCrypt.generate(password(version, data[1]), salt(data[0]), cost), 23);
}
/**
* Compares a bcrypt hash of the form $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
* with the computed hash from the given password. The bcrypt algorithm parameters are derived from the reference
* bcrypt hash string.
*
* @param data A 1-element array containing password.
*
* @return True if the computed hash is exactly equal to the reference hash, false otherwise.
*
* @throws CryptoException on bcrypt algorithm errors.
*/
@Override
public boolean compare(final String hash, final Object... data) throws CryptoException, StreamException
{
if (data.length != 1) {
throw new IllegalArgumentException("Expected exactly one element in data array but got " + data.length);
}
final BCryptParameters params = new BCryptParameters(hash);
final byte[] computed = BCrypt.generate(password(params.getVersion(), data[0]), params.getSalt(), params.getCost());
for (int i = 0; i < 23; i++) {
if (params.getHash()[i] != computed[i]) {
return false;
}
}
return true;
}
/**
* Encodes an input byte array into a string using the configured encoder.
*
* @param bytes Input bytes to encode.
* @param length Number of bytes of input to encode.
*
* @return Input encoded as a string.
*/
private static String encode(final byte[] bytes, final int length)
{
final Encoder encoder = new Base64Encoder.Builder().setAlphabet(ALPHABET).setPadding(false).build();
// Only want 184 bits (23 bytes) of the output
final ByteBuffer input = ByteBuffer.wrap(bytes, 0, length);
final CharBuffer output = CharBuffer.allocate(encoder.outputSize(length));
encoder.encode(input, output);
encoder.finalize(output);
return output.flip().toString();
}
/**
* Decodes an input string into a byte array using the configured decoder.
*
* @param input Input string to decode.
* @param length Desired output size in bytes.
*
* @return Input decoded as a byte array.
*/
private static byte[] decode(final String input, final int length)
{
final Decoder decoder = new Base64Decoder.Builder().setAlphabet(ALPHABET).setPadding(false).build();
final ByteBuffer output = ByteBuffer.allocate(decoder.outputSize(input.length()));
decoder.decode(CharBuffer.wrap(input), output);
decoder.finalize(output);
output.flip();
if (output.limit() != length) {
throw new IllegalArgumentException("Input is not of the expected size: " + output.limit() + "!=" + length);
}
return ByteUtil.toArray(output);
}
/**
* Converts an input object into a salt as an array of bytes.
*
* @param data Input salt as a byte array or encoded string.
*
* @return Salt as byte array.
*/
private static byte[] salt(final Object data)
{
if (data instanceof byte[]) {
return (byte[]) data;
} else if (data instanceof String) {
return decode((String) data, 16);
}
throw new IllegalArgumentException("Expected byte array or base-64 string.");
}
/**
* Converts an input object into a password as an array of UTF-8 bytes. A null terminator is added if the supplied
* data does not end with one.
*
* @param version Bcrypt version, e.g. "2a".
* @param data Input password.
*
* @return Null terminated password as UTF-8 byte array.
*/
private static byte[] password(final String version, final Object data)
{
if (data instanceof byte[]) {
final byte[] origData = (byte[]) data;
final byte[] newData;
if (origData[origData.length - 1] != 0x00) {
newData = new byte[origData.length + 1];
System.arraycopy(origData, 0, newData, 0, origData.length);
newData[newData.length - 1] = 0x00;
} else {
newData = origData;
}
return newData;
}
final StringBuilder sb = new StringBuilder();
if (data instanceof char[]) {
sb.append((char[]) data);
} else if (data instanceof String) {
sb.append((String) data);
} else {
throw new IllegalArgumentException("Expected byte array or string.");
}
if (sb.charAt(sb.length() - 1) != '\0') {
// Version 2a and later requires null terminator on password
sb.append('\0');
}
return sb.toString().getBytes(StandardCharsets.UTF_8);
}
/**
* Handles encoding and decoding a bcrypt hash of the form
* $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy.
*/
public static class BCryptParameters
{
/** bcrypt version. */
private final String version;
/** bcrypt cost. */
private final int cost;
/** bcrypt salt. */
private final byte[] salt;
/** bcrypt hash. */
private final byte[] hash;
/**
* Decodes bcrypt parameters from a string.
*
* @param bCryptString bcrypt hash of the form
* $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
*/
protected BCryptParameters(final String bCryptString)
{
if (!bCryptString.startsWith("$2")) {
throw new IllegalArgumentException("Expected bcrypt hash of the form $2n$cost$salthash");
}
final String[] parts = bCryptString.split("\\$");
if (parts.length != 4) {
throw new IllegalArgumentException("Invalid bcrypt hash");
}
version = parts[1];
cost = Integer.parseInt(parts[2]);
salt = decode(parts[3].substring(0, 22), 16);
hash = decode(parts[3].substring(22), 23);
}
/** @return bcrypt version. */
public String getVersion()
{
return version;
}
/** @return bcrypt cost in the range [4, 31]. */
public int getCost()
{
return cost;
}
/** @return bcrypt salt. */
public byte[] getSalt()
{
return salt;
}
/** @return bcrypt hash. */
public byte[] getHash()
{
return hash;
}
/**
* Produces an encoded bcrypt hash string from bcrypt parameter data.
*
* @return Bcrypt hash of the form $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy.
*/
public String encode()
{
return new StringBuilder(60)
.append('$')
.append(version)
.append('$')
.append(cost)
.append('$')
.append(BCryptHashBean.encode(salt, 16))
.append(BCryptHashBean.encode(hash, 23))
.toString();
}
/**
* Produces an encoded bcrypt hash string from bcrypt parameters and a provided hash string.
*
* @param hash Encoded bcrypt hash bytes; e.g. the value produced from {@link #hash(Object...)}.
*
* @return Bcrypt hash of the form $2n$cost$xxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy.
*/
public String encode(final String hash)
{
return new StringBuilder(60)
.append('$')
.append(version)
.append('$')
.append(cost)
.append('$')
.append(BCryptHashBean.encode(salt, 16))
.append(hash)
.toString();
}
}
}