org.jgroups.protocols.ASYM_ENCRYPT Maven / Gradle / Ivy
package org.jgroups.protocols;
import org.jgroups.*;
import org.jgroups.annotations.MBean;
import org.jgroups.annotations.ManagedAttribute;
import org.jgroups.annotations.Property;
import org.jgroups.conf.ClassConfigurator;
import org.jgroups.protocols.pbcast.GMS;
import org.jgroups.util.*;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;
import java.security.spec.X509EncodedKeySpec;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
/**
* Encrypts and decrypts communication in JGroups by using a secret key distributed to all cluster members by the
* key server (coordinator) using asymmetric (public/private key) encryption.
*
* The secret key is identical for all cluster members and is used to encrypt messages when sending and decrypt them
* when receiving messages.
*
* This protocol is typically placed under {@link org.jgroups.protocols.pbcast.NAKACK2}.
*
* The current keyserver (always the coordinator) generates a secret key. When a new member joins, it asks the keyserver
* for the secret key. The keyserver encrypts the secret key with the joiner's public key and the joiner decrypts it with
* its private key and then installs it and starts encrypting and decrypting messages with the secret key.
*
* View changes that identify a new keyserver will result in a new secret key being generated and then distributed to
* all cluster members. This overhead can be substantial in an application with a reasonable member churn.
*
* This protocol is suited for an application that does not ship with a known key but instead it is generated and
* distributed by the keyserver.
*
* Since messages can only get encrypted and decrypted when the secret key was received from the keyserver, messages
* are dropped when the secret key hasn't been installed yet.
*
* @author Bela Ban
* @author Steve Woodcock
*/
@MBean(description="Asymmetric encryption protocol. The secret key for encryption and decryption of messages is fetched " +
"from a key server (the coordinator) via asymmetric encryption")
public class ASYM_ENCRYPT extends Encrypt {
protected static final short GMS_ID=ClassConfigurator.getProtocolId(GMS.class);
@Property(description="When a node leaves, change the secret group key, preventing old members from eavesdropping")
protected boolean change_key_on_leave;
@Property(description="Change the secret group key when the coordinator changes. If enabled, this will take " +
"place even if change_key_on_leave is disabled.")
protected boolean change_key_on_coord_leave=true;
@Property(description="If true, a separate KeyExchange protocol (somewhere in the stack) is used to" +
" fetch the shared secret key. If false, the default (built-in) key exchange protocol will be used.")
protected boolean use_external_key_exchange;
protected KeyExchange key_exchange;
protected volatile Address key_server_addr;
protected volatile boolean send_group_keys; // set by handleView()
protected KeyPair key_pair; // to store own's public/private Key
protected Cipher asym_cipher; // decrypting cypher for secret key requests
protected final Map pub_map=new ConcurrentHashMap<>(); // map of members and their public keys
// cache server address between reception of INSTALL_MERGE_VIEW and sending of VIEW (MergeView)
protected static final ThreadLocal srv_addr=new ThreadLocal<>();
@Override
public ASYM_ENCRYPT setKeyStoreEntry(KeyStore.PrivateKeyEntry entry) {
this.key_pair = new KeyPair(entry.getCertificate().getPublicKey(), entry.getPrivateKey());
return this;
}
public boolean getChangeKeyOnLeave() {return change_key_on_leave;}
public ASYM_ENCRYPT setChangeKeyOnLeave(boolean c) {change_key_on_leave=c; return this;}
public boolean getChangeKeyOnCoordLeave() {return change_key_on_coord_leave;}
public ASYM_ENCRYPT setChangeKeyOnCoordLeave(boolean c) {change_key_on_coord_leave=c; return this;}
public boolean getUseExternalKeyExchange() {return use_external_key_exchange;}
public ASYM_ENCRYPT setUseExternalKeyExchange(boolean u) {use_external_key_exchange=u; return this;}
public KeyPair keyPair() {return key_pair;}
public Cipher asymCipher() {return asym_cipher;}
public Address keyServerAddr() {return key_server_addr;}
public ASYM_ENCRYPT keyServerAddr(Address ks) {this.key_server_addr=ks; return this;}
public List providedDownServices() {
return Arrays.asList(Event.GET_SECRET_KEY, Event.SET_SECRET_KEY);
}
@ManagedAttribute(description="Keys in the public key map")
public String getPublicKeys() {
return pub_map.keySet().toString();
}
@ManagedAttribute(description="The current key server")
public String getKeyServerAddress() {return key_server_addr != null? key_server_addr.toString() : "null";}
@ManagedAttribute(description="True if this member is the current key server, false otherwise")
public boolean isKeyServer() {
return Objects.equals(key_server_addr, local_addr);
}
public void init() throws Exception {
SecretKey k=createSecretKey();
byte[] encoded=k.getEncoded();
if(encoded == null)
throw new IllegalArgumentException(String.format("secret key %s/%s does not support encoding (FIPS enabled?)",
k.getAlgorithm(), k.getFormat()));
send_group_keys=false;
initKeyPair();
super.init();
if(use_external_key_exchange)
fetchAndSetKeyExchange();
}
public void start() throws Exception {
super.start();
pub_map.put(local_addr, key_pair.getPublic().getEncoded());
}
public Object down(Event evt) {
if(evt.type() == Event.INSTALL_MERGE_VIEW) { // only received by the merge *leader*
// the new group key will be added to the next INSTALL_MERGE_VIEW message (if !use_external_key_exchange)
createNewKey("because of an INSTALL_MERGE_VIEW event");
}
return super.down(evt);
}
public Object down(Message msg) {
Processing processing=skipDownMessage(msg);
if(processing == Processing.PROCESS)
return super.down(msg);
if(processing == Processing.SKIP)
return down_prot.down(msg);
return null; // DROP
}
public Object up(Event evt) {
switch(evt.type()) {
case Event.GET_SECRET_KEY:
return new Tuple<>(secret_key, sym_version);
case Event.SET_SECRET_KEY:
Tuple tuple=evt.arg();
try {
installSharedGroupKey(null, tuple.getVal1(), tuple.getVal2());
}
catch(Exception ex) {
log.error("failed setting group key", ex);
}
return null;
}
return up_prot.up(evt);
}
public Object up(Message msg) {
if(dropMulticastMessageFromNonMember(msg))
return null;
if(skipUpMessage(msg))
return up_prot.up(msg);
return super.up(msg);
}
public void up(MessageBatch batch) {
Iterator it=batch.iterator();
while(it.hasNext()) {
Message msg=it.next();
if(dropMulticastMessageFromNonMember(msg)) {
it.remove();
continue;
}
if(skipUpMessage(msg)) {
try {
up_prot.up(msg);
it.remove();
}
catch(Throwable t) {
log.error("failed passing up message from %s: %s, ex=%s", msg.src(), msg.printHeaders(), t);
}
}
}
if(!batch.isEmpty())
super.up(batch); // decrypt the rest of the messages in the batch (if any)
}
protected boolean dropMulticastMessageFromNonMember(Message msg) {
return msg.dest() == null &&
!inView(msg.src(), String.format("%s: dropped multicast message from non-member %s", local_addr, msg.getSrc()));
}
public ASYM_ENCRYPT fetchAndSetKeyExchange() {
if((key_exchange=stack.findProtocol(KeyExchange.class)) == null)
throw new IllegalStateException(KeyExchange.class.getSimpleName() + " not found in stack");
return this;
}
protected static void cacheServerAddress(Address srv) {
srv_addr.set(srv);
}
protected static Address getCachedServerAddress() {
Address retval=srv_addr.get();
srv_addr.remove();
return retval;
}
/**
* Processes a message with a GMS header (e.g. by adding the secret key to a JOIN response) and returns true if
* the message should be passed down (not encrypted) or false if the message needs to be encrypted
* @return Processing {@link Processing#DROP} if the message needs to be dropped, {@link Processing#SKIP} if the
* message needs to be skipped (not encrypted), or {@link Processing#PROCESS} if the message needs to be
* processed (= encrypted)
*/
protected Processing skipDownMessage(Message msg) {
GMS.GmsHeader hdr=msg.getHeader(GMS_ID);
if(hdr == null)
return Processing.PROCESS;
switch(hdr.getType()) {
case GMS.GmsHeader.JOIN_REQ:
case GMS.GmsHeader.JOIN_REQ_WITH_STATE_TRANSFER:
case GMS.GmsHeader.MERGE_RSP:
if(!use_external_key_exchange) {
// attach our public key to the JOIN-REQ
Message copy=addKeysToMessage(msg, true, false, null);
down_prot.down(copy);
return Processing.DROP;
}
return Processing.SKIP;
case GMS.GmsHeader.JOIN_RSP:
return addMetadata(msg,false, msg.getDest(), true);
case GMS.GmsHeader.VIEW:
boolean tmp=send_group_keys;
send_group_keys=false;
return addMetadata(msg, tmp, null, tmp);
case GMS.GmsHeader.INSTALL_MERGE_VIEW:
// a new group key was created in down(INSTALL_MERGE_VIEW)
if(Objects.equals(local_addr, msg.dest()))
break;
return addMetadata(msg, true, null, true);
case GMS.GmsHeader.MERGE_REQ:
case GMS.GmsHeader.VIEW_ACK:
case GMS.GmsHeader.GET_DIGEST_REQ:
case GMS.GmsHeader.GET_DIGEST_RSP:
return Processing.SKIP;
}
return Processing.PROCESS;
}
/** Checks if the message contains a public key (and adds it to pub_map if present) or an encrypted group key
* (and installs it if present) */
protected boolean skipUpMessage(Message msg) {
GMS.GmsHeader hdr=msg.getHeader(GMS_ID);
if(hdr == null)
return false;
EncryptHeader h=msg.getHeader(id);
switch(hdr.getType()) {
case GMS.GmsHeader.JOIN_REQ:
case GMS.GmsHeader.JOIN_REQ_WITH_STATE_TRANSFER:
case GMS.GmsHeader.MERGE_RSP:
return processEncryptMessage(msg, h, true);
case GMS.GmsHeader.JOIN_RSP:
case GMS.GmsHeader.VIEW:
case GMS.GmsHeader.INSTALL_MERGE_VIEW:
if(hdr.getType() == GMS.GmsHeader.INSTALL_MERGE_VIEW)
cacheServerAddress(h.server());
return processEncryptMessage(msg, h, false);
case GMS.GmsHeader.MERGE_REQ:
case GMS.GmsHeader.VIEW_ACK:
case GMS.GmsHeader.GET_DIGEST_REQ:
case GMS.GmsHeader.GET_DIGEST_RSP:
return true;
}
return false;
}
protected boolean processEncryptMessage(Message msg, EncryptHeader hdr, boolean retval) {
if(hdr == null)
return retval;
switch(hdr.type) {
case EncryptHeader.INSTALL_KEYS:
removeKeysFromMessageAndInstall(msg, hdr.version());
break;
case EncryptHeader.FETCH_SHARED_KEY:
if(!Objects.equals(local_addr, msg.getSrc())) {
try {
Address key_server=hdr.server() != null? hdr.server() : msg.src();
if(log.isTraceEnabled())
log.trace("%s: fetching group key from %s", local_addr, key_server);
key_exchange.fetchSecretKeyFrom(key_server);
}
catch(Exception e) {
log.warn("%s: failed fetching group key from %s: %s", local_addr, msg.src(), e);
}
}
break;
}
return retval;
}
protected void installPublicKeys(Address sender, byte[] buf, int offset, int length) {
ByteArrayDataInputStream in=new ByteArrayDataInputStream(buf, offset, length);
try {
int num_keys=in.readInt();
for(int i=0; i < num_keys; i++) {
Address mbr=Util.readAddress(in);
int len=in.readInt();
byte[] key=new byte[len];
in.readFully(key, 0, key.length);
pub_map.put(mbr, key);
}
log.trace("%s: added %d public keys to local cache", local_addr, num_keys);
}
catch(Exception ex) {
log.error("%s: failed reading public keys received from %s: %s", local_addr, sender, ex);
}
}
protected Processing addMetadata(Message msg, boolean add_secret_keys,
Address include_secret_key_only_for, boolean attach_fetch_key_header) {
try {
if(use_external_key_exchange && !attach_fetch_key_header)
return Processing.PROCESS;
Message encr_msg=encrypt(msg); // makes a copy
if(use_external_key_exchange) {
// attach a FETCH_SHARED_KEY to the message; this causes the recipient to fetch and install the
// shared key *before* delivering the message (so it can be decrypted)
Address srv=key_exchange.getServerLocation();
if(srv == null)
srv=getCachedServerAddress();
log.trace("%s: asking %s to fetch the shared group key %s via an external key exchange protocol (srv=%s)",
local_addr, encr_msg.getDest() == null? "all members" : encr_msg.getDest(),
Util.byteArrayToHexString(sym_version), srv);
encr_msg.putHeader(id, new EncryptHeader(EncryptHeader.FETCH_SHARED_KEY, symVersion(), getIv(encr_msg)).server(srv));
}
else {
encr_msg=addKeysToMessage(encr_msg, false, add_secret_keys, include_secret_key_only_for);
if(add_secret_keys || include_secret_key_only_for != null)
log.trace("%s: sending encrypted group key to %s (version: %s)", local_addr,
encr_msg.getDest() == null? "all members" : encr_msg.getDest(),
Util.byteArrayToHexString(sym_version));
}
down_prot.down(encr_msg);
return Processing.DROP; // the encrypted msg was already sent; no need to send the un-encrypted msg
}
catch(Exception ex) {
log.warn("%s: unable to send message to %s: %s", msg.getDest() == null? "all" : msg.getDest(), local_addr, ex);
return Processing.PROCESS;
}
}
/**
* Adds the public and/or encrypted shared keys to the payload of msg. If msg already has a payload, the message
* will be copied and the new payload consists of the keys and the original payload
* @param msg The original message
* @return A copy of the message
*/
protected Message addKeysToMessage(Message msg, boolean copy, boolean add_secret_keys, Address serialize_only) {
ByteArrayDataOutputStream out=new ByteArrayDataOutputStream(pub_map.size() * 200 + msg.getLength());
try {
serializeKeys(out, add_secret_keys, serialize_only);
if(msg.getLength() > 0) // add the original buffer
out.write(msg.getArray(), msg.getOffset(), msg.getLength());
return (copy? msg.copy(true, true) : msg).setArray(out.getBuffer())
.putHeader(id, new EncryptHeader(EncryptHeader.INSTALL_KEYS, symVersion(), getIv(msg)));
}
catch(Throwable t) {
log.error("%s: failed adding keys to message: %s", local_addr, t);
return null;
}
}
/**
* Removes the public and/or private keys from the payload of msg and installs them. If there is some payload left
* (the original payload), the offset of the message will be changed. Otherwise, the payload will be nulled, to
* re-create the original message
*/
protected void removeKeysFromMessageAndInstall(Message msg, byte[] version) {
ByteArrayDataInputStream in=new ByteArrayDataInputStream(msg.getArray(), msg.getOffset(), msg.getLength());
unserializeAndInstallKeys(msg.getSrc(), version, in);
int len=msg.getLength(), offset=msg.getOffset(), bytes_read=in.position();
// we can modify the original message as the sender sends a copy (even on retransmissions)
if(offset + bytes_read == len)
msg.setArray(null, 0, 0); // the original payload must have been null
else
msg.setArray(msg.getArray(), offset+bytes_read, len-bytes_read);
}
/** Serializes all public keys and their corresponding encrypted shared group keys into a buffer */
protected void serializeKeys(ByteArrayDataOutputStream out, boolean serialize_shared_keys,
Address serialize_only) throws Exception {
out.writeInt(pub_map.size()); // number of entries (actual value is written after serialization)
int num=0;
for(Map.Entry e: pub_map.entrySet()) {
Address mbr=e.getKey();
byte[] public_key=e.getValue(); // the encoded public key
Util.writeAddress(mbr, out);
// public keys
out.writeInt(public_key.length);
out.write(public_key, 0, public_key.length);
if(serialize_shared_keys || Objects.equals(mbr, serialize_only)) {
PublicKey pk=makePublicKey(public_key);
byte[] encrypted_shared_key=encryptSecretKey(secret_key, pk); // the encrypted shared group key
out.writeInt(encrypted_shared_key.length);
out.write(encrypted_shared_key, 0, encrypted_shared_key.length);
}
else
out.writeInt(0);
num++;
}
int curr_pos=out.position();
out.position(0).writeInt(num);
out.position(curr_pos);
}
/** Unserializes public keys and installs them to pub_map, then reads encrypted shared keys and install our own */
protected void unserializeAndInstallKeys(Address sender, byte[] version, ByteArrayDataInputStream in) {
try {
int num_keys=in.readInt();
for(int i=0; i < num_keys; i++) {
Address mbr=Util.readAddress(in);
int len=in.readInt();
if(len > 0) {
byte[] public_key=new byte[len];
in.readFully(public_key, 0, public_key.length);
pub_map.put(mbr, public_key);
}
if((len=in.readInt()) > 0) {
byte[] encrypted_shared_group_key=new byte[len];
in.readFully(encrypted_shared_group_key, 0, encrypted_shared_group_key.length);
if(local_addr.equals(mbr)) {
try {
SecretKey tmp=decodeKey(encrypted_shared_group_key);
if(tmp != null)
installSharedGroupKey(sender, tmp, version); // otherwise set the received key as the shared key
}
catch(Exception e) {
log.warn("%s: unable to process key received from %s: %s", local_addr, sender, e);
}
}
}
}
}
catch(Exception ex) {
log.error("%s: failed reading keys received from %s: %s", local_addr, sender, ex);
}
}
protected static ByteArray serializeKeys(Map keys) throws Exception {
int num_keys=keys.size();
if(num_keys == 0)
return null;
ByteArrayDataOutputStream out=new ByteArrayDataOutputStream(num_keys * 100);
out.writeInt(num_keys);
for(Map.Entry e: keys.entrySet()) {
Util.writeAddress(e.getKey(), out);
byte[] val=e.getValue();
out.writeInt(val.length);
out.write(val, 0, val.length);
}
return out.getBuffer();
}
protected Map unserializeKeys(Address sender, byte[] buf, int offset, int length) {
Map map=new HashMap<>();
ByteArrayDataInputStream in=new ByteArrayDataInputStream(buf, offset, length);
try {
int num_keys=in.readInt();
for(int i=0; i < num_keys; i++) {
Address mbr=Util.readAddress(in);
int len=in.readInt();
byte[] key=new byte[len];
in.readFully(key, 0, key.length);
map.put(mbr, key);
}
}
catch(Exception ex) {
log.error("%s: failed reading keys received from %s: %s", local_addr, sender, ex);
}
return map;
}
/** Initialise the symmetric key if none is supplied in a keystore */
protected SecretKey createSecretKey() throws Exception {
KeyGenerator keyGen=null;
// see if we have a provider specified
if(provider != null && !provider.trim().isEmpty())
keyGen=KeyGenerator.getInstance(getAlgorithm(sym_algorithm), provider);
else
keyGen=KeyGenerator.getInstance(getAlgorithm(sym_algorithm));
// generate the key using the defined init properties
keyGen.init(sym_keylength);
return keyGen.generateKey();
}
/** Generates the public/private key pair from the init params */
protected void initKeyPair() throws Exception {
if (this.key_pair == null) {
// generate keys according to the specified algorithms
// generate publicKey and Private Key
KeyPairGenerator KpairGen=null;
if(provider != null && !provider.trim().isEmpty())
KpairGen=KeyPairGenerator.getInstance(getAlgorithm(asym_algorithm), provider);
else
KpairGen=KeyPairGenerator.getInstance(getAlgorithm(asym_algorithm));
KpairGen.initialize(asym_keylength,new SecureRandom());
key_pair=KpairGen.generateKeyPair();
}
// set up the Cipher to decrypt secret key responses encrypted with our key
if(provider != null && !provider.trim().isEmpty())
asym_cipher=Cipher.getInstance(asym_algorithm, provider);
else
asym_cipher=Cipher.getInstance(asym_algorithm);
asym_cipher.init(Cipher.DECRYPT_MODE, key_pair.getPrivate());
}
@Override protected void handleView(View v) {
boolean left_mbrs, create_new_key, key_server_changed;
pub_map.keySet().retainAll(v.getMembers());
synchronized(this) {
key_server_changed=!Objects.equals(v.getCoord(), key_server_addr);
left_mbrs=this.view != null && !v.containsMembers(this.view.getMembersRaw());
super.handleView(v);
key_server_addr=v.getCoord(); // the coordinator is the keyserver
create_new_key=secret_key == null // always create a group key the first time (key is null)
|| change_key_on_leave && left_mbrs // && has higher precedence than ||
|| change_key_on_coord_leave && key_server_changed;
// if we get a MergeView, the secret key has already been created (in down(INSTALL_MERGE_VIEW)
create_new_key&=!(v instanceof MergeView);
// keys will be added to VIEW in down()
send_group_keys=create_new_key || v instanceof MergeView;
if(!Objects.equals(key_server_addr, local_addr))
return; // all non-coordinators are done at this point
if(key_server_changed)
log.debug("%s: I'm the new key server", local_addr);
if(create_new_key)
createNewKey("because of new view " + v);
}
}
protected void createNewKey(String message) {
try {
this.secret_key=createSecretKey();
initSymCiphers(sym_algorithm, secret_key);
log.debug("%s: created new group key (version: %s) %s", local_addr, Util.byteArrayToHexString(sym_version), message);
cacheGroupKey(sym_version);
}
catch(Exception ex) {
log.error("%s: failed creating group key and initializing ciphers", local_addr, ex);
}
}
protected synchronized void installSharedGroupKey(Address sender, SecretKey key, byte[] version) throws Exception {
if(Arrays.equals(this.sym_version, version)) {
log.debug("%s: ignoring group key received from %s (version: %s); it has already been installed",
local_addr, sender != null? sender : "key exchange protocol", Util.byteArrayToHexString(version));
return;
}
log.debug("%s: installing group key received from %s (version: %s)",
local_addr, sender != null? sender : "key exchange protocol", Util.byteArrayToHexString(version));
secret_key=key;
initSymCiphers(sym_algorithm, key);
sym_version=version;
cacheGroupKey(version);
}
/** Cache the current shared key to decrypt messages encrypted with the old shared group key */
protected void cacheGroupKey(byte[] version) throws Exception {
// put the previous key into the map
if(secret_key != null)
key_map.putIfAbsent(new AsciiString(version), secret_key);
}
/** Encrypts the current secret key with the requester's public key (the requester will decrypt it with its private key) */
protected byte[] encryptSecretKey(Key secret_key, PublicKey public_key) throws Exception {
Cipher tmp;
if (provider != null && !provider.trim().isEmpty())
tmp=Cipher.getInstance(asym_algorithm, provider);
else
tmp=Cipher.getInstance(asym_algorithm);
tmp.init(Cipher.ENCRYPT_MODE, public_key);
// encrypt current secret key
return tmp.doFinal(secret_key.getEncoded());
}
protected SecretKeySpec decodeKey(byte[] encodedKey) throws Exception {
byte[] keyBytes;
synchronized(this) {
try {
keyBytes=asym_cipher.doFinal(encodedKey);
}
catch (BadPaddingException | IllegalBlockSizeException e) {
// if any exception is thrown, this cipher object may need to be reset before it can be used again.
asym_cipher.init(Cipher.DECRYPT_MODE, key_pair.getPrivate());
throw e;
}
}
try {
SecretKeySpec keySpec=new SecretKeySpec(keyBytes, getAlgorithm(sym_algorithm));
Cipher temp;
if (provider != null && !provider.trim().isEmpty())
temp=Cipher.getInstance(sym_algorithm, provider);
else
temp=Cipher.getInstance(sym_algorithm);
temp.init(Cipher.SECRET_KEY, keySpec);
return keySpec;
}
catch(Exception e) {
log.error(Util.getMessage("FailedDecodingKey"), e);
return null;
}
}
/** Used to reconstitute public key sent in byte form from peer */
protected PublicKey makePublicKey(byte[] encodedKey) {
PublicKey pubKey=null;
try {
KeyFactory KeyFac=KeyFactory.getInstance(getAlgorithm(asym_algorithm));
X509EncodedKeySpec x509KeySpec=new X509EncodedKeySpec(encodedKey);
pubKey=KeyFac.generatePublic(x509KeySpec);
}
catch(Exception e) {
e.printStackTrace();
}
return pubKey;
}
protected byte[] getIv(Message msg) {
EncryptHeader h=msg.getHeader(id);
if (h == null)
return null;
return h.iv();
}
protected enum Processing {SKIP, PROCESS, DROP}
}
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