1 files changed, 1 insertions, 209 deletions

diff --git a/src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha1.java b/src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha1.java
index f40eec55..13593778 100644
--- a/src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha1.java
+++ b/src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha1.java
@@ -1,77 +1,21 @@
 package eu.siacs.conversations.crypto.sasl;
 
-import android.util.Base64;
-import android.util.LruCache;
-
-import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.crypto.digests.SHA1Digest;
 import org.bouncycastle.crypto.macs.HMac;
-import org.bouncycastle.crypto.params.KeyParameter;
 
-import java.math.BigInteger;
-import java.nio.charset.Charset;
-import java.security.InvalidKeyException;
 import java.security.SecureRandom;
 
 import eu.siacs.conversations.entities.Account;
-import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.xml.TagWriter;
 
-public class ScramSha1 extends SaslMechanism {
-	// TODO: When channel binding (SCRAM-SHA1-PLUS) is supported in future, generalize this to indicate support and/or usage.
-	final private static String GS2_HEADER = "n,,";
-	private String clientFirstMessageBare;
-	final private String clientNonce;
-	private byte[] serverSignature = null;
-	private static HMac HMAC;
-	private static Digest DIGEST;
-	private static final byte[] CLIENT_KEY_BYTES = "Client Key".getBytes();
-	private static final byte[] SERVER_KEY_BYTES = "Server Key".getBytes();
-
-	public static class KeyPair {
-		final public byte[] clientKey;
-		final public byte[] serverKey;
-
-		public KeyPair(final byte[] clientKey, final byte[] serverKey) {
-			this.clientKey = clientKey;
-			this.serverKey = serverKey;
-		}
-	}
-
-	private static final LruCache<String, KeyPair> CACHE;
-
+public class ScramSha1 extends ScramMechanism {
 	static {
 		DIGEST = new SHA1Digest();
 		HMAC = new HMac(new SHA1Digest());
-		CACHE = new LruCache<String, KeyPair>(10) {
-			protected KeyPair create(final String k) {
-				// Map keys are "bytesToHex(JID),bytesToHex(password),bytesToHex(salt),iterations".
-				// Changing any of these values forces a cache miss. `CryptoHelper.bytesToHex()'
-				// is applied to prevent commas in the strings breaking things.
-				final String[] kparts = k.split(",", 4);
-				try {
-					final byte[] saltedPassword, serverKey, clientKey;
-					saltedPassword = hi(CryptoHelper.hexToString(kparts[1]).getBytes(),
-							Base64.decode(CryptoHelper.hexToString(kparts[2]), Base64.DEFAULT), Integer.valueOf(kparts[3]));
-					serverKey = hmac(saltedPassword, SERVER_KEY_BYTES);
-					clientKey = hmac(saltedPassword, CLIENT_KEY_BYTES);
-
-					return new KeyPair(clientKey, serverKey);
-				} catch (final InvalidKeyException | NumberFormatException e) {
-					return null;
-				}
-			}
-		};
 	}
 
-	private State state = State.INITIAL;
-
 	public ScramSha1(final TagWriter tagWriter, final Account account, final SecureRandom rng) {
 		super(tagWriter, account, rng);
-
-		// This nonce should be different for each authentication attempt.
-		clientNonce = new BigInteger(100, this.rng).toString(32);
-		clientFirstMessageBare = "";
 	}
 
 	@Override
@@ -83,156 +27,4 @@ public class ScramSha1 extends SaslMechanism {
 	public String getMechanism() {
 		return "SCRAM-SHA-1";
 	}
-
-	@Override
-	public String getClientFirstMessage() {
-		if (clientFirstMessageBare.isEmpty() && state == State.INITIAL) {
-			clientFirstMessageBare = "n=" + CryptoHelper.saslEscape(CryptoHelper.saslPrep(account.getUsername())) +
-				",r=" + this.clientNonce;
-			state = State.AUTH_TEXT_SENT;
-		}
-		return Base64.encodeToString(
-				(GS2_HEADER + clientFirstMessageBare).getBytes(Charset.defaultCharset()),
-				Base64.NO_WRAP);
-	}
-
-	@Override
-	public String getResponse(final String challenge) throws AuthenticationException {
-		switch (state) {
-			case AUTH_TEXT_SENT:
-				if (challenge == null) {
-					throw new AuthenticationException("challenge can not be null");
-				}
-				byte[] serverFirstMessage = Base64.decode(challenge, Base64.DEFAULT);
-				final Tokenizer tokenizer = new Tokenizer(serverFirstMessage);
-				String nonce = "";
-				int iterationCount = -1;
-				String salt = "";
-				for (final String token : tokenizer) {
-					if (token.charAt(1) == '=') {
-						switch (token.charAt(0)) {
-							case 'i':
-								try {
-									iterationCount = Integer.parseInt(token.substring(2));
-								} catch (final NumberFormatException e) {
-									throw new AuthenticationException(e);
-								}
-								break;
-							case 's':
-								salt = token.substring(2);
-								break;
-							case 'r':
-								nonce = token.substring(2);
-								break;
-							case 'm':
-								/*
-								 * RFC 5802:
-								 * m: This attribute is reserved for future extensibility.  In this
-								 * version of SCRAM, its presence in a client or a server message
-								 * MUST cause authentication failure when the attribute is parsed by
-								 * the other end.
-								 */
-								throw new AuthenticationException("Server sent reserved token: `m'");
-						}
-					}
-				}
-
-				if (iterationCount < 0) {
-					throw new AuthenticationException("Server did not send iteration count");
-				}
-				if (nonce.isEmpty() || !nonce.startsWith(clientNonce)) {
-					throw new AuthenticationException("Server nonce does not contain client nonce: " + nonce);
-				}
-				if (salt.isEmpty()) {
-					throw new AuthenticationException("Server sent empty salt");
-				}
-
-				final String clientFinalMessageWithoutProof = "c=" + Base64.encodeToString(
-						GS2_HEADER.getBytes(), Base64.NO_WRAP) + ",r=" + nonce;
-				final byte[] authMessage = (clientFirstMessageBare + ',' + new String(serverFirstMessage) + ','
-						+ clientFinalMessageWithoutProof).getBytes();
-
-				// Map keys are "bytesToHex(JID),bytesToHex(password),bytesToHex(salt),iterations".
-				final KeyPair keys = CACHE.get(
-						CryptoHelper.bytesToHex(account.getJid().toBareJid().toString().getBytes()) + ","
-						+ CryptoHelper.bytesToHex(account.getPassword().getBytes()) + ","
-						+ CryptoHelper.bytesToHex(salt.getBytes()) + ","
-						+ String.valueOf(iterationCount)
-						);
-				if (keys == null) {
-					throw new AuthenticationException("Invalid keys generated");
-				}
-				final byte[] clientSignature;
-				try {
-					serverSignature = hmac(keys.serverKey, authMessage);
-					final byte[] storedKey = digest(keys.clientKey);
-
-					clientSignature = hmac(storedKey, authMessage);
-
-				} catch (final InvalidKeyException e) {
-					throw new AuthenticationException(e);
-				}
-
-				final byte[] clientProof = new byte[keys.clientKey.length];
-
-				for (int i = 0; i < clientProof.length; i++) {
-					clientProof[i] = (byte) (keys.clientKey[i] ^ clientSignature[i]);
-				}
-
-
-				final String clientFinalMessage = clientFinalMessageWithoutProof + ",p=" +
-					Base64.encodeToString(clientProof, Base64.NO_WRAP);
-				state = State.RESPONSE_SENT;
-				return Base64.encodeToString(clientFinalMessage.getBytes(), Base64.NO_WRAP);
-			case RESPONSE_SENT:
-				try {
-					final String clientCalculatedServerFinalMessage = "v=" +
-							Base64.encodeToString(serverSignature, Base64.NO_WRAP);
-					if (!clientCalculatedServerFinalMessage.equals(new String(Base64.decode(challenge, Base64.DEFAULT)))) {
-						throw new Exception();
-					};
-					state = State.VALID_SERVER_RESPONSE;
-					return "";
-				} catch(Exception e) {
-					throw new AuthenticationException("Server final message does not match calculated final message");
-				}
-			default:
-				throw new InvalidStateException(state);
-		}
-	}
-
-	public static synchronized byte[] hmac(final byte[] key, final byte[] input)
-		throws InvalidKeyException {
-		HMAC.init(new KeyParameter(key));
-		HMAC.update(input, 0, input.length);
-		final byte[] out = new byte[HMAC.getMacSize()];
-		HMAC.doFinal(out, 0);
-		return out;
-	}
-
-	public static synchronized byte[] digest(byte[] bytes) {
-		DIGEST.reset();
-		DIGEST.update(bytes, 0, bytes.length);
-		final byte[] out = new byte[DIGEST.getDigestSize()];
-		DIGEST.doFinal(out, 0);
-		return out;
-	}
-
-	/*
-	 * Hi() is, essentially, PBKDF2 [RFC2898] with HMAC() as the
-	 * pseudorandom function (PRF) and with dkLen == output length of
-	 * HMAC() == output length of H().
-	 */
-	private static synchronized byte[] hi(final byte[] key, final byte[] salt, final int iterations)
-		throws InvalidKeyException {
-		byte[] u = hmac(key, CryptoHelper.concatenateByteArrays(salt, CryptoHelper.ONE));
-		byte[] out = u.clone();
-		for (int i = 1; i < iterations; i++) {
-			u = hmac(key, u);
-			for (int j = 0; j < u.length; j++) {
-				out[j] ^= u[j];
-			}
-		}
-		return out;
-	}
 }