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Remove weird roundabout way of doing decryption

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This commit is contained in:
Niels Andriesse
2021-05-13 15:27:08 +10:00
parent d83c257491
commit d9348c5442
12 changed files with 37 additions and 147 deletions
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29
libsignal/src/main/java/org/session/libsignal/service/api/crypto/SignalServiceCipher.java
View File

@@ -31,8 +31,6 @@ import org.session.libsignal.service.internal.push.SignalServiceProtos.Content;
import org.session.libsignal.service.internal.push.SignalServiceProtos.DataMessage;
import org.session.libsignal.service.internal.push.SignalServiceProtos.ReceiptMessage;
import org.session.libsignal.service.internal.push.SignalServiceProtos.TypingMessage;
import org.session.libsignal.service.loki.api.crypto.SessionProtocol;
import org.session.libsignal.service.loki.api.crypto.SessionProtocolUtilities;
import org.session.libsignal.service.loki.LokiAPIDatabaseProtocol;
import java.util.ArrayList;
@@ -51,13 +49,10 @@ public class SignalServiceCipher {
@SuppressWarnings("unused")
private static final String TAG = SignalServiceCipher.class.getSimpleName();
private final SessionProtocol sessionProtocolImpl;
private final LokiAPIDatabaseProtocol apiDB;
public SignalServiceCipher(SessionProtocol sessionProtocolImpl,
LokiAPIDatabaseProtocol apiDB)
public SignalServiceCipher(LokiAPIDatabaseProtocol apiDB)
{
this.sessionProtocolImpl = sessionProtocolImpl;
this.apiDB = apiDB;
}
@@ -125,27 +120,7 @@ public class SignalServiceCipher {
protected Plaintext decrypt(SignalServiceEnvelope envelope, byte[] ciphertext) throws InvalidMetadataMessageException
{
byte[] paddedMessage;
Metadata metadata;
if (envelope.isClosedGroupCiphertext()) {
String groupPublicKey = envelope.getSource();
kotlin.Pair<byte[], String> plaintextAndSenderPublicKey = SessionProtocolUtilities.INSTANCE.decryptClosedGroupCiphertext(ciphertext, groupPublicKey, apiDB, sessionProtocolImpl);
paddedMessage = plaintextAndSenderPublicKey.getFirst();
String senderPublicKey = plaintextAndSenderPublicKey.getSecond();
metadata = new Metadata(senderPublicKey, 1, envelope.getTimestamp(), false);
} else if (envelope.isUnidentifiedSender()) {
ECKeyPair userX25519KeyPair = apiDB.getUserX25519KeyPair();
kotlin.Pair<byte[], String> plaintextAndSenderPublicKey = sessionProtocolImpl.decrypt(ciphertext, userX25519KeyPair);
paddedMessage = plaintextAndSenderPublicKey.getFirst();
String senderPublicKey = plaintextAndSenderPublicKey.getSecond();
metadata = new Metadata(senderPublicKey, 1, envelope.getTimestamp(), false);
} else {
throw new InvalidMetadataMessageException("Unknown type: " + envelope.getType());
}
byte[] data = PushTransportDetails.getStrippedPaddingMessageBody(paddedMessage);
return new Plaintext(metadata, data);
throw new IllegalStateException("This shouldn't be used anymore");
}
private SignalServiceDataMessage createSignalServiceMessage(Metadata metadata, DataMessage content) throws ProtocolInvalidMessageException {

53
libsignal/src/main/java/org/session/libsignal/service/loki/SessionProtocol.kt
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@@ -1,53 +0,0 @@
package org.session.libsignal.service.loki.api.crypto
import org.session.libsignal.libsignal.ecc.ECKeyPair
import org.session.libsignal.service.loki.LokiAPIDatabaseProtocol
interface SessionProtocol {
sealed class Exception(val description: String) : kotlin.Exception(description) {
// Encryption
object NoUserED25519KeyPair : Exception("Couldn't find user ED25519 key pair.")
object SigningFailed : Exception("Couldn't sign message.")
object EncryptionFailed : Exception("Couldn't encrypt message.")
// Decryption
object NoData : Exception("Received an empty envelope.")
object InvalidGroupPublicKey : Exception("Invalid group public key.")
object NoGroupKeyPair : Exception("Missing group key pair.")
object DecryptionFailed : Exception("Couldn't decrypt message.")
object InvalidSignature : Exception("Invalid message signature.")
}
/**
* Decrypts `ciphertext` using the Session protocol and `x25519KeyPair`.
*
* @param ciphertext the data to decrypt.
* @param x25519KeyPair the key pair to use for decryption. This could be the current user's key pair, or the key pair of a closed group.
*
* @return the padded plaintext.
*/
fun decrypt(ciphertext: ByteArray, x25519KeyPair: ECKeyPair): Pair<ByteArray, String>
}
object SessionProtocolUtilities {
fun decryptClosedGroupCiphertext(ciphertext: ByteArray, groupPublicKey: String, apiDB: LokiAPIDatabaseProtocol, sessionProtocolImpl: SessionProtocol): Pair<ByteArray, String> {
val encryptionKeyPairs = apiDB.getClosedGroupEncryptionKeyPairs(groupPublicKey).toMutableList()
if (encryptionKeyPairs.isEmpty()) { throw SessionProtocol.Exception.NoGroupKeyPair }
// Loop through all known group key pairs in reverse order (i.e. try the latest key pair first (which'll more than
// likely be the one we want) but try older ones in case that didn't work)
var encryptionKeyPair = encryptionKeyPairs.removeAt(encryptionKeyPairs.lastIndex)
fun decrypt(): Pair<ByteArray, String> {
try {
return sessionProtocolImpl.decrypt(ciphertext, encryptionKeyPair)
} catch(exception: Exception) {
if (encryptionKeyPairs.isNotEmpty()) {
encryptionKeyPair = encryptionKeyPairs.removeAt(encryptionKeyPairs.lastIndex)
return decrypt()
} else {
throw exception
}
}
}
return decrypt()
}
}