Remove some obsolete stuff, rev protocol version.

node/ECC.hpp

@@ -35,6 +35,7 @@
 #include <openssl/pem.h>
 #include <openssl/bn.h>
 
+#define ZT_ECC_EPHEMERAL_PUBLIC_KEY_LEN 97 /* Single ECC P-384 key */
 #define ZT_ECC_PUBLIC_KEY_SET_LEN (97 * 2) /* Two ECC P-384 keys */
 #define ZT_ECC_PRIVATE_KEY_SET_LEN (48 * 2) /* Two ECC P-384 secret keys */
 #define ZT_ECC_SIGNATURE_LEN 96 /* NIST P-384 ECDSA signature */
@@ -52,9 +53,10 @@ public:
 
 namespace ZeroTier {
 
-#define ZT_ECC_PUBLIC_KEY_SET_LEN 64
+#define ZT_ECC_EPHEMERAL_PUBLIC_KEY_LEN 32 /* Single C25519 ECDH key */
-#define ZT_ECC_PRIVATE_KEY_SET_LEN 64
+#define ZT_ECC_PUBLIC_KEY_SET_LEN 64 /* C25519 and Ed25519 keys */
-#define ZT_ECC_SIGNATURE_LEN 96
+#define ZT_ECC_PRIVATE_KEY_SET_LEN 64 /* C25519 and Ed25519 secret keys */
+#define ZT_ECC_SIGNATURE_LEN 96 /* Ed25519 signature plus (not necessary) hash */
 
 class ECC
 {

node/Packet.cpp

@@ -1009,7 +1009,6 @@ void Packet::armor(const void *key,bool encryptPayload,const AES aesKeys[2])
 {
 	uint8_t *const data = reinterpret_cast<uint8_t *>(unsafeData());
 	if ((aesKeys) && (encryptPayload)) {
-		//char tmp0[16],tmp1[16];
 		setCipher(ZT_PROTO_CIPHER_SUITE__AES_GMAC_SIV);
 
 		uint8_t *const payload = data + ZT_PACKET_IDX_VERB;

node/Packet.hpp

@@ -59,10 +59,15 @@
  * 10 - 1.4.0 ... 1.4.6
  * 11 - 1.4.7 ... 1.4.8
  *    + Multipath capability and load balancing (beta)
- * 12 - 1.4.8 ... CURRENT (1.4 series)
+ * 12 - 1.4.8 ... 1.16.0
  *    + AES-GMAC-SIV backported for faster peer-to-peer crypto
+ * 13 - 1.16.0 ... CURRENT
+ *    + Old deprecated "encrypted" flag removed
+ *    + Ephemeral keying with second encryption pass to hide HELLO etc.
+ *    + Encrypted HELLO packets to anyone but roots
+ *    + Remove deprecated parsing of LAN announcements
  */
-#define ZT_PROTO_VERSION 12
+#define ZT_PROTO_VERSION 13
 
 /**
  * Minimum supported protocol version
@@ -100,6 +105,18 @@
  */
 #define ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012 1
 
+/**
+ * Cipher suite: NONE
+ *
+ * This differs from POLY1305/NONE in that *no* crypto is done, not even
+ * authentication. This is for trusted local LAN interconnects for internal
+ * SDN use within a data center.
+ *
+ * For this mode the MAC field becomes a trusted path ID and must match the
+ * configured ID of a trusted path or the packet is discarded.
+ */
+#define ZT_PROTO_CIPHER_SUITE__NO_CRYPTO_TRUSTED_PATH 2
+
 /**
  * AES-GMAC-SIV backported from 2.x
  */
@@ -116,23 +133,15 @@
 #define ZT_KBKDF_LABEL_AES_GMAC_SIV_K1 '1'
 
 /**
- * Cipher suite: NONE
+ * Header flag indicating ephemeral keying and second encryption pass.
  *
- * This differs from POLY1305/NONE in that *no* crypto is done, not even
+ * If this is set, the packet will have an ephemeral key appended to it its payload
- * authentication. This is for trusted local LAN interconnects for internal
+ * will be encrypted with AES-CTR using this ephemeral key and the packet's header
- * SDN use within a data center.
+ * as an IV.
  *
- * For this mode the MAC field becomes a trusted path ID and must match the
+ * Note that this is a reuse of a flag that has long been deprecated and ignored.
- * configured ID of a trusted path or the packet is discarded.
  */
-#define ZT_PROTO_CIPHER_SUITE__NO_CRYPTO_TRUSTED_PATH 2
+#define ZT_PROTO_FLAG_EXTENDED_ARMOR 0x80
-
-/**
- * DEPRECATED payload encrypted flag, may be re-used in the future.
- *
- * This has been replaced by the three-bit cipher suite selection field.
- */
-#define ZT_PROTO_FLAG_ENCRYPTED 0x80
 
 /**
  * Header flag indicating that a packet is fragmented
@@ -147,66 +156,8 @@
  */
 #define ZT_PROTO_VERB_FLAG_COMPRESSED 0x80
 
-/**
+/*
- * Rounds used for Salsa20 encryption in ZT
+ * Rounds used for deprecated Salsa20 encryption
- *
- * Discussion:
- *
- * DJB (Salsa20's designer) designed Salsa20 with a significant margin of 20
- * rounds, but has said repeatedly that 12 is likely sufficient. So far (as of
- * July 2015) there are no published attacks against 12 rounds, let alone 20.
- *
- * In cryptography, a "break" means something different from what it means in
- * common discussion. If a cipher is 256 bits strong and someone finds a way
- * to reduce key search to 254 bits, this constitutes a "break" in the academic
- * literature. 254 bits is still far beyond what can be leveraged to accomplish
- * a "break" as most people would understand it -- the actual decryption and
- * reading of traffic.
- *
- * Nevertheless, "attacks only get better" as cryptographers like to say. As
- * a result, they recommend not using anything that's shown any weakness even
- * if that weakness is so far only meaningful to academics. It may be a sign
- * of a deeper problem.
- *
- * So why choose a lower round count?
- *
- * Turns out the speed difference is nontrivial. On a Macbook Pro (Core i3) 20
- * rounds of SSE-optimized Salsa20 achieves ~508mb/sec/core, while 12 rounds
- * hits ~832mb/sec/core. ZeroTier is designed for multiple objectives:
- * security, simplicity, and performance. In this case a deference was made
- * for performance.
- *
- * Meta discussion:
- *
- * The cipher is not the thing you should be paranoid about.
- *
- * I'll qualify that. If the cipher is known to be weak, like RC4, or has a
- * key size that is too small, like DES, then yes you should worry about
- * the cipher.
- *
- * But if the cipher is strong and your adversary is anyone other than the
- * intelligence apparatus of a major superpower, you are fine in that
- * department.
- *
- * Go ahead. Search for the last ten vulnerabilities discovered in SSL. Not
- * a single one involved the breaking of a cipher. Now broaden your search.
- * Look for issues with SSH, IPSec, etc. The only cipher-related issues you
- * will find might involve the use of RC4 or MD5, algorithms with known
- * issues or small key/digest sizes. But even weak ciphers are difficult to
- * exploit in the real world -- you usually need a lot of data and a lot of
- * compute time. No, virtually EVERY security vulnerability you will find
- * involves a problem with the IMPLEMENTATION not with the cipher.
- *
- * A flaw in ZeroTier's protocol or code is incredibly, unbelievably
- * more likely than a flaw in Salsa20 or any other cipher or cryptographic
- * primitive it uses. We're talking odds of dying in a car wreck vs. odds of
- * being personally impacted on the head by a meteorite. Nobody without a
- * billion dollar budget is going to break into your network by actually
- * cracking Salsa20/12 (or even /8) in the field.
- *
- * So stop worrying about the cipher unless you are, say, the Kremlin and your
- * adversary is the NSA and the GCHQ. In that case... well that's above my
- * pay grade. I'll just say defense in depth.
  */
 #define ZT_PROTO_SALSA20_ROUNDS 12
 
@@ -1267,12 +1218,6 @@ public:
 	{
 		unsigned char &b = (*this)[ZT_PACKET_IDX_FLAGS];
 		b = (b & 0xc7) | (unsigned char)((c << 3) & 0x38); // bits: FFCCCHHH
-		// Set DEPRECATED "encrypted" flag -- used by pre-1.0.3 peers
-		if (c == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012) {
-			b |= ZT_PROTO_FLAG_ENCRYPTED;
-		} else {
-			b &= (~ZT_PROTO_FLAG_ENCRYPTED);
-		}
 	}
 
 	/**

node/Switch.cpp

@@ -83,31 +83,7 @@ void Switch::onRemotePacket(void *tPtr,const int64_t localSocket,const InetAddre
 		const SharedPtr<Path> path(RR->topology->getPath(localSocket,fromAddr));
 		path->received(now);
 
-		if (len == 13) {
+		if (len > ZT_PROTO_MIN_FRAGMENT_LENGTH) {
-			/* LEGACY: before VERB_PUSH_DIRECT_PATHS, peers used broadcast
-			 * announcements on the LAN to solve the 'same network problem.' We
-			 * no longer send these, but we'll listen for them for a while to
-			 * locate peers with versions <1.0.4. */
-
-			const Address beaconAddr(reinterpret_cast<const char *>(data) + 8,5);
-			if (beaconAddr == RR->identity.address()) {
-				return;
-			}
-			if (!RR->node->shouldUsePathForZeroTierTraffic(tPtr,beaconAddr,localSocket,fromAddr)) {
-				return;
-			}
-			const SharedPtr<Peer> peer(RR->topology->getPeer(tPtr,beaconAddr));
-			if (peer) { // we'll only respond to beacons from known peers
-				if ((now - _lastBeaconResponse) >= 2500) { // limit rate of responses
-					_lastBeaconResponse = now;
-					Packet outp(peer->address(),RR->identity.address(),Packet::VERB_NOP);
-					outp.armor(peer->key(),true,peer->aesKeysIfSupported());
-					Metrics::pkt_nop_out++;
-					path->send(RR,tPtr,outp.data(),outp.size(),now);
-				}
-			}
-
-		} else if (len > ZT_PROTO_MIN_FRAGMENT_LENGTH) { // SECURITY: min length check is important since we do some C-style stuff below!
 			if (reinterpret_cast<const uint8_t *>(data)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR] == ZT_PACKET_FRAGMENT_INDICATOR) {
 				// Handle fragment ----------------------------------------------------