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Code Issues Projects Releases Wiki Activity

Implement first prototype of GroupMessageValidator

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This commit is contained in:
Torsten Grote
2016-10-18 14:28:21 -02:00
parent 8dc529cc3f
commit a6e3827127
5 changed files with 205 additions and 15 deletions
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30
briar-api/src/org/briarproject/api/privategroup/MessageType.java Normal file
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@@ -0,0 +1,30 @@
package org.briarproject.api.privategroup;
public enum MessageType {
NEW_MEMBER(0),
JOIN(1),
POST(2);
int value;
MessageType(int value) {
this.value = value;
}
public static MessageType valueOf(int value) {
switch (value) {
case 0:
return NEW_MEMBER;
case 1:
return JOIN;
case 2:
return POST;
default:
throw new IllegalArgumentException();
}
}
public int getInt() {
return value;
}
}

8
briar-core/src/org/briarproject/privategroup/Constants.java
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@@ -1,8 +1,14 @@
package org.briarproject.privategroup;
import static org.briarproject.clients.BdfConstants.MSG_KEY_READ;
interface Constants {
// Database keys
String KEY_READ = "read";
String KEY_TYPE = "type";
String KEY_TIMESTAMP = "timestamp";
String KEY_READ = MSG_KEY_READ;
String KEY_AUTHOR_NAME = "authorName";
String KEY_AUTHOR_PUBLIC_KEY = "authorPublicKey";
}

166
briar-core/src/org/briarproject/privategroup/GroupMessageValidator.java
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@@ -3,11 +3,12 @@ package org.briarproject.privategroup;
import org.briarproject.api.FormatException;
import org.briarproject.api.clients.BdfMessageContext;
import org.briarproject.api.clients.ClientHelper;
import org.briarproject.api.crypto.CryptoComponent;
import org.briarproject.api.data.BdfDictionary;
import org.briarproject.api.data.BdfList;
import org.briarproject.api.data.MetadataEncoder;
import org.briarproject.api.identity.AuthorFactory;
import org.briarproject.api.privategroup.MessageType;
import org.briarproject.api.privategroup.PrivateGroup;
import org.briarproject.api.privategroup.PrivateGroupFactory;
import org.briarproject.api.sync.Group;
import org.briarproject.api.sync.InvalidMessageException;
import org.briarproject.api.sync.Message;
@@ -15,29 +16,178 @@ import org.briarproject.api.sync.MessageId;
import org.briarproject.api.system.Clock;
import org.briarproject.clients.BdfMessageValidator;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import static org.briarproject.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
import static org.briarproject.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
import static org.briarproject.api.identity.AuthorConstants.MAX_SIGNATURE_LENGTH;
import static org.briarproject.api.privategroup.PrivateGroupConstants.MAX_GROUP_POST_BODY_LENGTH;
import static org.briarproject.privategroup.Constants.KEY_AUTHOR_NAME;
import static org.briarproject.privategroup.Constants.KEY_AUTHOR_PUBLIC_KEY;
import static org.briarproject.privategroup.Constants.KEY_READ;
import static org.briarproject.privategroup.Constants.KEY_TIMESTAMP;
import static org.briarproject.privategroup.Constants.KEY_TYPE;
class GroupMessageValidator extends BdfMessageValidator {
private final CryptoComponent crypto;
private final AuthorFactory authorFactory;
private final PrivateGroupFactory groupFactory;
GroupMessageValidator(CryptoComponent crypto, AuthorFactory authorFactory,
GroupMessageValidator(PrivateGroupFactory groupFactory,
ClientHelper clientHelper, MetadataEncoder metadataEncoder,
Clock clock) {
super(clientHelper, metadataEncoder, clock);
this.crypto = crypto;
this.authorFactory = authorFactory;
this.groupFactory = groupFactory;
}
@Override
protected BdfMessageContext validateMessage(Message m, Group g,
BdfList body) throws InvalidMessageException, FormatException {
checkSize(body, 4, 7);
// message type (int)
int type = body.getLong(0).intValue();
body.removeElementAt(0);
// member_name (string)
String member_name = body.getString(0);
checkLength(member_name, 1, MAX_AUTHOR_NAME_LENGTH);
// member_public_key (raw)
byte[] member_public_key = body.getRaw(1);
checkLength(member_public_key, 1, MAX_PUBLIC_KEY_LENGTH);
BdfMessageContext c;
switch (MessageType.valueOf(type)) {
case NEW_MEMBER:
c = validateNewMember(m, g, body, member_name,
member_public_key);
addMessageMetadata(c, member_name, member_public_key,
m.getTimestamp());
break;
case JOIN:
c = validateJoin(m, g, body, member_name, member_public_key);
addMessageMetadata(c, member_name, member_public_key,
m.getTimestamp());
break;
case POST:
c = validatePost(m, g, body, member_name, member_public_key);
break;
default:
throw new InvalidMessageException("Unknown Message Type");
}
c.getDictionary().put(KEY_TYPE, type);
return c;
}
private BdfMessageContext validateNewMember(Message m, Group g,
BdfList body, String member_name, byte[] member_public_key)
throws InvalidMessageException, FormatException {
// The content is a BDF list with three elements
checkSize(body, 3);
// signature (raw)
// signature with the creator's private key over a list with 4 elements
byte[] signature = body.getRaw(2);
checkLength(signature, 1, MAX_SIGNATURE_LENGTH);
// Verify Signature
BdfList signed = BdfList.of(g.getId(), m.getTimestamp(), member_name,
member_public_key);
PrivateGroup group = groupFactory.parsePrivateGroup(g);
byte[] creatorPublicKey = group.getAuthor().getPublicKey();
clientHelper.verifySignature(signature, creatorPublicKey, signed);
// Return the metadata and no dependencies
BdfDictionary meta = new BdfDictionary();
return new BdfMessageContext(meta);
}
private BdfMessageContext validateJoin(Message m, Group g, BdfList body,
String member_name, byte[] member_public_key)
throws InvalidMessageException, FormatException {
// The content is a BDF list with four elements
checkSize(body, 4);
// new_member_id (raw)
// the identifier of a new member message
// with the same member_name and member_public_key
byte[] new_member_id = body.getRaw(2);
checkLength(new_member_id, MessageId.LENGTH);
// signature (raw)
// a signature with the member's private key over a list with 5 elements
byte[] signature = body.getRaw(3);
checkLength(signature, 1, MAX_SIGNATURE_LENGTH);
// Verify Signature
BdfList signed = BdfList.of(g.getId(), m.getTimestamp(), member_name,
member_public_key, new_member_id);
clientHelper.verifySignature(signature, member_public_key, signed);
// The new member message is a dependency
Collection<MessageId> dependencies =
Collections.singleton(new MessageId(new_member_id));
// Return the metadata and dependencies
BdfDictionary meta = new BdfDictionary();
Collection<MessageId> dependencies = Collections.emptyList();
return new BdfMessageContext(meta, dependencies);
}
private BdfMessageContext validatePost(Message m, Group g, BdfList body,
String member_name, byte[] member_public_key)
throws InvalidMessageException, FormatException {
// The content is a BDF list with six elements
checkSize(body, 6);
// parent_id (raw or null)
// the identifier of the post to which this is a reply, if any
byte[] parent_id = body.getOptionalRaw(2);
if (parent_id != null) {
checkLength(parent_id, MessageId.LENGTH);
}
// previous_message_id (raw)
// the identifier of the member's previous post or join message
byte[] previous_message_id = body.getRaw(3);
checkLength(previous_message_id, MessageId.LENGTH);
// content (string)
String content = body.getString(4);
checkLength(content, 0, MAX_GROUP_POST_BODY_LENGTH);
// signature (raw)
// a signature with the member's private key over a list with 7 elements
byte[] signature = body.getRaw(5);
checkLength(signature, 1, MAX_SIGNATURE_LENGTH);
// Verify Signature
BdfList signed = BdfList.of(g.getId(), m.getTimestamp(), member_name,
member_public_key, parent_id, previous_message_id, content);
clientHelper.verifySignature(signature, member_public_key, signed);
// The parent post, if any,
// and the member's previous message are dependencies
Collection<MessageId> dependencies = new ArrayList<MessageId>();
if (parent_id != null) dependencies.add(new MessageId(parent_id));
dependencies.add(new MessageId(previous_message_id));
// Return the metadata and dependencies
BdfDictionary meta = new BdfDictionary();
return new BdfMessageContext(meta, dependencies);
}
private void addMessageMetadata(BdfMessageContext c, String authorName,
byte[] pubKey, long time) {
c.getDictionary().put(KEY_TIMESTAMP, time);
c.getDictionary().put(KEY_READ, false);
c.getDictionary().put(KEY_AUTHOR_NAME, authorName);
c.getDictionary().put(KEY_AUTHOR_PUBLIC_KEY, pubKey);
}
}

6
briar-core/src/org/briarproject/privategroup/PrivateGroupManagerImpl.java
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@@ -198,6 +198,12 @@ public class PrivateGroupManagerImpl extends BdfIncomingMessageHook implements
trackIncomingMessage(txn, m);
// TODO POST timestamp must be greater than the timestamps of the parent post, if any, and the member's previous message
// TODO JOIN timestamp must be equal to the timestamp of the new member message.
// TODO JOIN new_member_id must be the identifier of a NEW_MEMBER message with the same member_name and member_public_key
return true;
}

10
briar-core/src/org/briarproject/privategroup/PrivateGroupModule.java
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@@ -2,9 +2,7 @@ package org.briarproject.privategroup;
import org.briarproject.api.clients.ClientHelper;
import org.briarproject.api.contact.ContactManager;
import org.briarproject.api.crypto.CryptoComponent;
import org.briarproject.api.data.MetadataEncoder;
import org.briarproject.api.identity.AuthorFactory;
import org.briarproject.api.lifecycle.LifecycleManager;
import org.briarproject.api.messaging.ConversationManager;
import org.briarproject.api.privategroup.GroupMessageFactory;
@@ -59,11 +57,11 @@ public class PrivateGroupModule {
@Provides
@Singleton
GroupMessageValidator provideGroupMessageValidator(
ValidationManager validationManager, CryptoComponent crypto,
AuthorFactory authorFactory, ClientHelper clientHelper,
PrivateGroupFactory groupFactory,
ValidationManager validationManager, ClientHelper clientHelper,
MetadataEncoder metadataEncoder, Clock clock) {
GroupMessageValidator validator = new GroupMessageValidator(crypto,
authorFactory, clientHelper, metadataEncoder, clock);
GroupMessageValidator validator = new GroupMessageValidator(
groupFactory, clientHelper, metadataEncoder, clock);
validationManager.registerMessageValidator(
PrivateGroupManagerImpl.CLIENT_ID, validator);
return validator;