// procUID allows to process a sender UID from the header in parallel.
// senderUID is the JSON encoded UID message parsed from the header, res is
// the result channel used to communicate the result of the calculation.
func procUID(senderUID string, res chan *procUIDResult) {
var r procUIDResult
var err error
r.uidIndex = cipher.SHA256(cipher.SHA256([]byte(senderUID)))
r.msg, err = uid.NewJSON(senderUID)
if err != nil {
res <- &procUIDResult{uidIndex: nil, msg: nil, err: err}
return
}
// return results
res <- &r
}
// Encrypt encryptes the given UID message.
func (msg *Message) Encrypt() (UIDHash, UIDIndex []byte, UIDMessageEncrypted string) {
Message := msg.JSON()
// Calculate hash: UIDHash = sha256(UIDMessage)
UIDHash = cipher.SHA256(Message)
// Calculate hash: UIDIndex = sha256(UIDHash)
UIDIndex = cipher.SHA256(UIDHash)
// Encrypt UIDMessage: UIDMessageEncrypted = UIDIndex | nonce | aes_ctr(nonce, key=UIDHash, UIDMessage)
enc := cipher.AES256CTREncrypt(UIDHash, Message, cipher.RandReader)
uidEnc := make([]byte, sha256.Size+len(enc))
copy(uidEnc, UIDIndex)
copy(uidEnc[sha256.Size:], enc)
UIDMessageEncrypted = base64.Encode(uidEnc)
return
}
// NewNymAddress generates a new nym address.
func NewNymAddress(
domain string,
secret []byte,
expire int64,
singleUse bool,
minDelay, maxDelay int32,
id string,
pubkey *[ed25519.PublicKeySize]byte,
server string,
caCert []byte,
) (mixaddress, nymaddress string, err error) {
if err := identity.IsMapped(id); err != nil {
return "", "", log.Error(err)
}
if MixAddress == "" {
return "", "", log.Error("util: MixAddress undefined")
}
mixAddresses, err := client.GetMixKeys(MixAddress, caCert)
if err != nil {
return "", "", log.Error(err)
}
tmp := nymaddr.AddressTemplate{
Secret: secret,
System: 0,
MixCandidates: mixAddresses.Addresses,
Expire: expire,
SingleUse: singleUse,
MinDelay: minDelay,
MaxDelay: maxDelay,
}
nymAddress, err := tmp.NewAddress(MailboxAddress(pubkey, server),
cipher.SHA256([]byte(id)))
if err != nil {
return "", "", log.Error(err)
}
addr, err := nymaddr.ParseAddress(nymAddress)
if err != nil {
return "", "", log.Error(err)
}
return string(addr.MixAddress), base64.Encode(nymAddress), nil
}
func (ce *CtrlEngine) procInQueue(c *cli.Context, host string) error {
log.Debug("procInQueue()")
for {
// get message from msgDB
iqIdx, myID, contactID, msg, envelope, err := ce.msgDB.GetInQueue()
if err != nil {
return err
}
if myID == "" {
log.Debug("no more messages in inqueue")
break // no more messages in inqueue
}
if envelope {
log.Debugf("decrypt envelope (iqIdx=%d)", iqIdx)
// decrypt envelope
message, err := base64.Decode(msg)
if err != nil {
return log.Error(err)
}
privkey, server, secret, _, _, _, err := ce.msgDB.GetAccount(myID, contactID)
if err != nil {
return err
}
receiveTemplate := nymaddr.AddressTemplate{
Secret: secret[:],
}
var pubkey [32]byte
copy(pubkey[:], privkey[32:])
dec, nym, err := mixcrypt.ReceiveFromMix(receiveTemplate,
util.MailboxAddress(&pubkey, server), message)
if err != nil {
return log.Error(err)
}
if !bytes.Equal(nym, cipher.SHA256([]byte(myID))) {
// discard message
log.Warnf("ctrlengine: hashed nym does not match %s -> discard message", myID)
if err := ce.msgDB.DelInQueue(iqIdx); err != nil {
return err
}
} else {
log.Info("envelope successfully decrypted")
err := ce.msgDB.SetInQueue(iqIdx, base64.Encode(dec))
if err != nil {
return err
}
}
} else {
log.Debugf("decrypt message (iqIdx=%d)", iqIdx)
senderID, plainMsg, err := mutecryptDecrypt(c, ce.passphrase,
[]byte(msg), ce.fileTable.StatusFP)
if err != nil {
return err
}
if senderID == "" {
// message could not be decrypted, but we do not want to fail
if err := ce.msgDB.DelInQueue(iqIdx); err != nil {
return err
}
continue
}
// check if contact exists
contact, _, contactType, err := ce.msgDB.GetContact(myID, senderID)
if err != nil {
return log.Error(err)
}
// TODO: we do not have to do request UID message from server
// here, but we should use the one contained in the message and
// compare it with hash chain entry (doesn't compromise anonymity)
var drop bool
if contact == "" {
err := ce.contactAdd(myID, senderID, "", host, msgdb.GrayList, c)
if err != nil {
return log.Error(err)
}
} else if contactType == msgdb.BlackList {
// messages from black listed contacts are dropped directly
log.Debug("message from black listed contact dropped")
drop = true
}
err = ce.msgDB.RemoveInQueue(iqIdx, plainMsg, senderID, drop)
if err != nil {
return err
}
}
}
return nil
}
func TestSessions(t *testing.T) {
tmpdir, keyDB, err := createDB()
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(tmpdir)
defer keyDB.Close()
// make sure sessions are empty initially
sessionKey := base64.Encode(cipher.SHA512([]byte("key")))
rootKeyHash, _, _, err := keyDB.GetSession(sessionKey)
if err != sql.ErrNoRows {
t.Error("should fail with sql.ErrNoRows")
}
if rootKeyHash != "" {
t.Error("rootKeyHash is supposed to be empty")
}
// store root key hash
rk := base64.Encode(cipher.SHA256([]byte("rootkey")))
master := make([]byte, 96)
if _, err := io.ReadFull(cipher.RandReader, master); err != nil {
t.Fatal(err)
}
kdf := hkdf.New(sha512.New, master, nil, nil)
chainKey := make([]byte, 32)
if _, err := io.ReadFull(kdf, chainKey); err != nil {
t.Fatal(err)
}
send, recv, err := deriveKeys(chainKey, kdf)
if err != nil {
t.Fatal(err)
}
err = keyDB.AddSession(sessionKey, rk, base64.Encode(chainKey), send, recv)
if err != nil {
t.Fatal(err)
}
// check root key hash
rootKeyHash, _, n, err := keyDB.GetSession(sessionKey)
if err != nil {
t.Fatal(err)
}
if rootKeyHash != rk {
t.Error("rootKeyHash is supposed to equal rk")
}
if n != msg.NumOfFutureKeys {
t.Error("n is supposed to equal msg.NumOfFutureKeys")
}
// update root key hash
chainKey = make([]byte, 32)
if _, err := io.ReadFull(kdf, chainKey); err != nil {
t.Fatal(err)
}
send, recv, err = deriveKeys(chainKey, kdf)
if err != nil {
t.Fatal(err)
}
err = keyDB.AddSession(sessionKey, rk, base64.Encode(chainKey), send, recv)
if err != nil {
t.Fatal(err)
}
// check updated root key hash
rootKeyHash, _, n, err = keyDB.GetSession(sessionKey)
if err != nil {
t.Fatal(err)
}
if rootKeyHash != rk {
t.Error("rootKeyHash is supposed to equal rk")
}
if n != 2*msg.NumOfFutureKeys {
t.Error("n is supposed to equal 2*msg.NumOfFutureKeys")
}
// TODO: improve tests for message keys
_, err = keyDB.GetMessageKey(sessionKey, true, 0)
if err != nil {
t.Fatal(err)
}
if err := keyDB.DelMessageKey(sessionKey, true, 0); err != nil {
t.Fatal(err)
}
}
func (ce *CryptEngine) lookupHashChain(id string) error {
// map identity
mappedID, domain, err := identity.MapPlus(id)
if err != nil {
return err
}
// get JSON-RPC client
client, _, err := ce.cache.Get(domain, ce.keydPort, ce.keydHost, ce.homedir,
"KeyHashchain.LookupUID")
if err != nil {
return err
}
// Call KeyHashchain.LookupUID
content := make(map[string]interface{})
content["Identity"] = mappedID
reply, err := client.JSONRPCRequest("KeyHashchain.LookupUID", content)
if err != nil {
return err
}
hcPositions, ok := reply["HCPositions"].([]interface{})
if !ok {
if _, ok := reply["HCPositions"].(interface{}); !ok {
return log.Errorf("lookup found no entry of id '%s'", id)
}
return log.Error("cryptengine: lookup ID reply has the wrong type")
}
var TYPE, NONCE, HashID, CrUID, UIDIndex []byte
var matchFound bool
for k, v := range hcPositions {
hcPosFloat, ok := v.(float64)
if !ok {
return log.Errorf("cryptengine: lookup ID reply position entry %d has the wrong type", k)
}
hcPos := uint64(hcPosFloat)
hcEntry, err := ce.keyDB.GetHashChainEntry(domain, hcPos)
if err != nil {
return err
}
_, TYPE, NONCE, HashID, CrUID, UIDIndex, err = hashchain.SplitEntry(hcEntry)
if err != nil {
return err
}
if !bytes.Equal(TYPE, hashchain.Type) {
return log.Error("cryptengine: invalid entry type")
}
// Compute k1, k2 = CKDF(NONCE)
k1, k2 := cipher.CKDF(NONCE)
// Compute: HashIDTest = HASH(k1 | Identity)
tmp := make([]byte, len(k1)+len(mappedID))
copy(tmp, k1)
copy(tmp[len(k1):], mappedID)
HashIDTest := cipher.SHA256(tmp)
// If NOT: HashID == HashIDTest: Continue
if !bytes.Equal(HashID, HashIDTest) {
return log.Error("cryptengine: lookup ID returned bogus position")
}
log.Debugf("cryptengine: UIDIndex=%s", base64.Encode(UIDIndex))
// Check UID already exists in keyDB
_, pos, found, err := ce.keyDB.GetPublicUID(mappedID, hcPos)
if err != nil {
return err
}
if found && pos == hcPos {
// UID exists already -> skip entry
matchFound = true
continue
}
// Compute: IDKEY = HASH(k2 | Identity)
tmp = make([]byte, len(k2)+len(mappedID))
copy(tmp, k2)
copy(tmp[len(k2):], mappedID)
IDKEY := cipher.SHA256(tmp)
// Fetch from Key Repository: UIDMessageReply = GET(UIDIndex)
msgReply, err := ce.fetchUID(domain, UIDIndex)
if err != nil {
return err
}
// Decrypt UIDHash = AES_256_CBC_Decrypt( IDKEY, CrUID)
UIDHash := cipher.AES256CBCDecrypt(IDKEY, CrUID)
log.Debugf("cryptengine: UIDHash=%s", base64.Encode(UIDHash))
// Decrypt UIDMessageReply.UIDMessage with UIDHash
index, uid, err := msgReply.Decrypt(UIDHash)
if err != nil {
return err
}
log.Debugf("cryptengine: UIDMessage=%s", uid.JSON())
// Check index
if !bytes.Equal(index, UIDIndex) {
return log.Errorf("cryptengine: index != UIDIndex")
}
// Verify self signature
if err := uid.VerifySelfSig(); err != nil {
return log.Error(err)
}
// Verify server signature
if err := ce.verifyServerSig(uid, msgReply, hcPos); err != nil {
return err
}
// TODO: make sure the whole chain of UIDMessages is valid
// Store UIDMessage
if err := ce.keyDB.AddPublicUID(uid, hcPos); err != nil {
return err
}
matchFound = true
// If no further entry can be found, the latest UIDMessage entry has been found
}
if matchFound {
return nil
}
return log.Errorf("lookup found no entry of id '%s'", id)
}
// searchHashChain searches the local hash chain corresponding to the given id
// for the id. It talks to the corresponding key server to retrieve necessary
// UIDMessageReplys and stores found UIDMessages in the local keyDB.
func (ce *CryptEngine) searchHashChain(id string, searchOnly bool) error {
// map identity
mappedID, domain, err := identity.MapPlus(id)
if err != nil {
return err
}
// make sure we have a hashchain for the given domain
max, found, err := ce.keyDB.GetLastHashChainPos(domain)
if err != nil {
return err
}
if !found {
return log.Errorf("no hash chain entries found for domain '%s'", domain)
}
var TYPE, NONCE, HashID, CrUID, UIDIndex []byte
var matchFound bool
for i := uint64(0); i <= max; i++ {
hcEntry, err := ce.keyDB.GetHashChainEntry(domain, i)
if err != nil {
return err
}
log.Debugf("cryptengine: search hash chain entry %d: %s", i, hcEntry)
_, TYPE, NONCE, HashID, CrUID, UIDIndex, err = hashchain.SplitEntry(hcEntry)
if err != nil {
return err
}
if !bytes.Equal(TYPE, hashchain.Type) {
return log.Error("cryptengine: invalid hash chain entry type")
}
// Compute k1, k2 = CKDF(NONCE)
k1, k2 := cipher.CKDF(NONCE)
// Compute: HashIDTest = HASH(k1 | Identity)
tmp := make([]byte, len(k1)+len(mappedID))
copy(tmp, k1)
copy(tmp[len(k1):], mappedID)
HashIDTest := cipher.SHA256(tmp)
// If NOT: HashID == HashIDTest: Continue
if !bytes.Equal(HashID, HashIDTest) {
continue
}
if searchOnly {
return nil
}
log.Debugf("cryptengine: UIDIndex=%s", base64.Encode(UIDIndex))
// Check UID already exists in keyDB
_, pos, found, err := ce.keyDB.GetPublicUID(mappedID, i)
if err != nil {
return err
}
if found && pos == i {
// UID exists already -> skip entry
matchFound = true
continue
}
// Compute: IDKEY = HASH(k2 | Identity)
tmp = make([]byte, len(k2)+len(mappedID))
copy(tmp, k2)
copy(tmp[len(k2):], mappedID)
IDKEY := cipher.SHA256(tmp)
// Fetch from Key Repository: UIDMessageReply = GET(UIDIndex)
msgReply, err := ce.fetchUID(domain, UIDIndex)
if err != nil {
return err
}
// Decrypt UIDHash = AES_256_CBC_Decrypt( IDKEY, CrUID)
UIDHash := cipher.AES256CBCDecrypt(IDKEY, CrUID)
log.Debugf("cryptengine: UIDHash=%s", base64.Encode(UIDHash))
// Decrypt UIDMessageReply.UIDMessage with UIDHash
index, uid, err := msgReply.Decrypt(UIDHash)
if err != nil {
return err
}
log.Debugf("cryptengine: UIDMessage=%s", uid.JSON())
// Check index
if !bytes.Equal(index, UIDIndex) {
return log.Errorf("cryptengine: index != UIDIndex")
}
// Verify self signature
if err := uid.VerifySelfSig(); err != nil {
return log.Error(err)
}
// Verify server signature
if err := ce.verifyServerSig(uid, msgReply, i); err != nil {
return err
}
// TODO: make sure the whole chain of UIDMessages is valid
// Store UIDMessage
if err := ce.keyDB.AddPublicUID(uid, i); err != nil {
return err
}
matchFound = true
// If no further entry can be found, the latest UIDMessage entry has been found
}
if matchFound {
return nil
}
return log.Errorf("no hash chain entry found of id '%s'", id)
}
// validateHashChain validates the local hash chain for the given domain.
// That is, it checks that each entry has the correct length and the links are
// valid.
func (ce *CryptEngine) validateHashChain(domain string) error {
// make sure we have a hashchain for the given domain
max, found, err := ce.keyDB.GetLastHashChainPos(domain)
if err != nil {
return err
}
if !found {
return log.Errorf("no hash chain entries found for domain '%s'", domain)
}
var hashEntryN, TYPE, NONCE, HashID, CrUID, UIDIndex, hashEntryNminus1 []byte
for i := uint64(0); i <= max; i++ {
entry, err := ce.keyDB.GetHashChainEntry(domain, i)
if err != nil {
return err
}
log.Debugf("cryptengine: validate entry %d: %s", i, entry)
if i == 0 {
hashEntryNminus1 = make([]byte, sha256.Size)
} else {
hashEntryNminus1 = hashEntryN
}
hashEntryN, TYPE, NONCE, HashID, CrUID, UIDIndex, err = hashchain.SplitEntry(entry)
if err != nil {
return err
}
if !bytes.Equal(TYPE, hashchain.Type) {
return log.Error("cryptengine: invalid hash chain entry type")
}
entryN := make([]byte, 153)
copy(entryN, TYPE)
copy(entryN[1:], NONCE)
copy(entryN[9:], HashID)
copy(entryN[41:], CrUID)
copy(entryN[89:], UIDIndex)
copy(entryN[121:], hashEntryNminus1)
if !bytes.Equal(hashEntryN, cipher.SHA256(entryN)) {
return log.Errorf("cryptengine: hash chain entry %d invalid", i)
}
}
// get all private identities for the given domain
ids, err := ce.keyDB.GetPrivateIdentitiesForDomain(domain)
if err != nil {
return err
}
// make sure UIDMessageReplies are recorded in hash chain
for _, id := range ids {
_, msgReply, err := ce.keyDB.GetPrivateUID(id, false)
if err != nil {
return err
}
if msgReply != nil && msgReply.ENTRY.HASHCHAINPOS <= max {
entry, err := ce.keyDB.GetHashChainEntry(domain, msgReply.ENTRY.HASHCHAINPOS)
if err != nil {
return err
}
if entry != msgReply.ENTRY.HASHCHAINENTRY {
return log.Errorf("cryptengine: hash chain entry differs from UIDMessageReply (%s)", id)
}
}
}
return nil
}