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SCRAM remove cache. made digest and hmac non static 

DIGEST and HMAC were static variables. Those are initialized by
what ever concrete implementation gets executed first.

(Perform SCRAM-SHA1 first and those variables got initialized with
SHA1 variants)

For subsequent SHA256 executions those variables contained wrong
values.
This commit is contained in:
Daniel Gultsch 2020-12-30 15:57:42 +01:00
parent f23016c967
commit 692ee6c9fb
3 changed files with 48 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
src/main/java/eu/siacs/conversations/crypto/sasl/ScramMechanism.java
View File

@ -3,13 +3,11 @@ package eu.siacs.conversations.crypto.sasl;
import android.annotation.TargetApi;
import android.os.Build;
import android.util.Base64;
import android.util.LruCache;
import org.bouncycastle.crypto.Digest;
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;
@ -24,21 +22,15 @@ abstract class ScramMechanism extends SaslMechanism {
private final static String GS2_HEADER = "n,,";
private static final byte[] CLIENT_KEY_BYTES = "Client Key".getBytes();
private static final byte[] SERVER_KEY_BYTES = "Server Key".getBytes();
private static final LruCache<String, KeyPair> CACHE;
static HMac HMAC;
static Digest DIGEST;
static {
CACHE = new LruCache<String, KeyPair>(10) {
protected KeyPair create(final String k) {
// Map keys are "bytesToHex(JID),bytesToHex(password),bytesToHex(salt),iterations,SASL-Mechanism".
// 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(",", 5);
protected abstract HMac getHMAC();
protected abstract Digest getDigest();
private KeyPair getKeyPair(final String password, final String salt, final int iterations) {
try {
final byte[] saltedPassword, serverKey, clientKey;
saltedPassword = hi(CryptoHelper.hexToString(kParts[1]).getBytes(),
Base64.decode(CryptoHelper.hexToString(kParts[2]), Base64.DEFAULT), Integer.parseInt(kParts[3]));
saltedPassword = hi(password.getBytes(), Base64.decode(salt, Base64.DEFAULT), iterations);
serverKey = hmac(saltedPassword, SERVER_KEY_BYTES);
clientKey = hmac(saltedPassword, CLIENT_KEY_BYTES);
@ -47,8 +39,6 @@ abstract class ScramMechanism extends SaslMechanism {
return null;
}
}
};
}
private final String clientNonce;
protected State state = State.INITIAL;
@ -63,20 +53,21 @@ abstract class ScramMechanism extends SaslMechanism {
clientFirstMessageBare = "";
}
private 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);
private byte[] hmac(final byte[] key, final byte[] input) throws InvalidKeyException {
final HMac hMac = getHMAC();
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);
public byte[] digest(byte[] bytes) {
final Digest digest = getDigest();
digest.reset();
digest.update(bytes, 0, bytes.length);
final byte[] out = new byte[digest.getDigestSize()];
digest.doFinal(out, 0);
return out;
}
@ -85,7 +76,7 @@ abstract class ScramMechanism extends SaslMechanism {
* 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)
private 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();
@ -171,14 +162,7 @@ abstract class ScramMechanism extends SaslMechanism {
final byte[] authMessage = (clientFirstMessageBare + ',' + new String(serverFirstMessage) + ','
+ clientFinalMessageWithoutProof).getBytes();
// Map keys are "bytesToHex(JID),bytesToHex(password),bytesToHex(salt),iterations,SASL-Mechanism".
final KeyPair keys = CACHE.get(
CryptoHelper.bytesToHex(CryptoHelper.saslPrep(account.getJid().asBareJid().toEscapedString()).getBytes()) + ","
+ CryptoHelper.bytesToHex(CryptoHelper.saslPrep(account.getPassword()).getBytes()) + ","
+ CryptoHelper.bytesToHex(salt.getBytes()) + ","
+ iterationCount + ","
+ getMechanism()
);
final KeyPair keys = getKeyPair(CryptoHelper.saslPrep(account.getPassword()), salt, iterationCount);
if (keys == null) {
throw new AuthenticationException("Invalid keys generated");
}

13
src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha1.java
View File

@ -1,5 +1,6 @@
package eu.siacs.conversations.crypto.sasl;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.macs.HMac;
@ -9,9 +10,15 @@ import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.xml.TagWriter;
public class ScramSha1 extends ScramMechanism {
static {
DIGEST = new SHA1Digest();
HMAC = new HMac(new SHA1Digest());
@Override
protected HMac getHMAC() {
return new HMac(new SHA1Digest());
}
@Override
protected Digest getDigest() {
return new SHA1Digest();
}
public ScramSha1(final TagWriter tagWriter, final Account account, final SecureRandom rng) {

13
src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha256.java
View File

@ -1,5 +1,6 @@
package eu.siacs.conversations.crypto.sasl;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.macs.HMac;
@ -9,9 +10,15 @@ import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.xml.TagWriter;
public class ScramSha256 extends ScramMechanism {
static {
DIGEST = new SHA256Digest();
HMAC = new HMac(new SHA256Digest());
@Override
protected HMac getHMAC() {
return new HMac(new SHA256Digest());
}
@Override
protected Digest getDigest() {
return new SHA256Digest();
}
public ScramSha256(final TagWriter tagWriter, final Account account, final SecureRandom rng) {