narayana/conversations-classic
3
2
Fork 0
Code Issues 3 Pull requests 2 Actions Packages Projects Releases 4 Wiki Activity

SCRAM remove cache. made digest and hmac non static

Browse source 
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

72
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;
@ -24,30 +22,22 @@ 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);
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]));
serverKey = hmac(saltedPassword, SERVER_KEY_BYTES);
clientKey = hmac(saltedPassword, CLIENT_KEY_BYTES);
protected abstract HMac getHMAC();
return new KeyPair(clientKey, serverKey);
} catch (final InvalidKeyException | NumberFormatException e) {
return null;
}
}
};
protected abstract Digest getDigest();
private KeyPair getKeyPair(final String password, final String salt, final int iterations) {
try {
final byte[] saltedPassword, serverKey, clientKey;
saltedPassword = hi(password.getBytes(), Base64.decode(salt, Base64.DEFAULT), iterations);
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 final String clientNonce;
@ -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) {