new: more parrots and safety update (#227)

* new: PQ and other parrots

Add new preset parrots:
- HelloChrome_114_Padding_PSK_Shuf
- HelloChrome_115_PQ
- HelloChrome_115_PQ_PSK

* new: ShuffleChromeTLSExtensions

Implement a new function `ShuffleChromeTLSExtensions(exts []TLSExtension) []TLSExtension`.

* update: include psk parameter for parrot-related functions

Update following functions' prototype to accept an optional pskExtension (of type *FakePreSharedKeyExtension):
- `UClient(conn net.Conn, config *Config, clientHelloID ClientHelloID)` => `UClient(conn net.Conn, config *Config, clientHelloID ClientHelloID, pskExtension ...*FakePreSharedKeyExtension)`
- `UTLSIdToSpec(id ClientHelloID)` => `UTLSIdToSpec(id ClientHelloID, pskExtension ...*FakePreSharedKeyExtension)`

* new: pre-defined error from UTLSIdToSpec

Update UTLSIdToSpec to return more comprehensive errors by pre-defining them, allowing easier error comparing/unwrapping.

u_common.go

@@ -582,9 +582,17 @@ var (
 	HelloChrome_102         = ClientHelloID{helloChrome, "102", nil, nil}
 	HelloChrome_106_Shuffle = ClientHelloID{helloChrome, "106", nil, nil} // beta: shuffler enabled starting from 106
 
-	// Chrome with PSK: Chrome start sending this ClientHello after doing TLS 1.3 handshake with the same server.
-	HelloChrome_100_PSK      = ClientHelloID{helloChrome, "100_PSK", nil, nil} // beta: PSK extension added. uTLS doesn't fully support PSK. Use at your own risk.
-	HelloChrome_112_PSK_Shuf = ClientHelloID{helloChrome, "112_PSK", nil, nil} // beta: PSK extension added. uTLS doesn't fully support PSK. Use at your own risk.
+	// Chrome w/ PSK: Chrome start sending this ClientHello after doing TLS 1.3 handshake with the same server.
+	// Beta: PSK extension added. However, uTLS doesn't ship with full PSK support.
+	// Use at your own discretion.
+	HelloChrome_100_PSK              = ClientHelloID{helloChrome, "100_PSK", nil, nil}
+	HelloChrome_112_PSK_Shuf         = ClientHelloID{helloChrome, "112_PSK", nil, nil}
+	HelloChrome_114_Padding_PSK_Shuf = ClientHelloID{helloChrome, "114_PSK", nil, nil}
+
+	// Chrome w/ Post-Quantum Key Agreement
+	// Beta: PQ extension added. However, uTLS doesn't ship with full PQ support. Use at your own discretion.
+	HelloChrome_115_PQ     = ClientHelloID{helloChrome, "115_PQ", nil, nil}
+	HelloChrome_115_PQ_PSK = ClientHelloID{helloChrome, "115_PQ_PSK", nil, nil}
 
 	HelloIOS_Auto = HelloIOS_14
 	HelloIOS_11_1 = ClientHelloID{helloIOS, "111", nil, nil} // legacy "111" means 11.1

u_conn.go

@@ -24,6 +24,7 @@ type UConn struct {
 
 	Extensions    []TLSExtension
 	ClientHelloID ClientHelloID
+	pskExtension  []*FakePreSharedKeyExtension
 
 	ClientHelloBuilt bool
 	HandshakeState   PubClientHandshakeState
@@ -43,13 +44,13 @@ type UConn struct {
 
 // UClient returns a new uTLS client, with behavior depending on clientHelloID.
 // Config CAN be nil, but make sure to eventually specify ServerName.
-func UClient(conn net.Conn, config *Config, clientHelloID ClientHelloID) *UConn {
+func UClient(conn net.Conn, config *Config, clientHelloID ClientHelloID, pskExtension ...*FakePreSharedKeyExtension) *UConn {
 	if config == nil {
 		config = &Config{}
 	}
 	tlsConn := Conn{conn: conn, config: config, isClient: true}
 	handshakeState := PubClientHandshakeState{C: &tlsConn, Hello: &PubClientHelloMsg{}}
-	uconn := UConn{Conn: &tlsConn, ClientHelloID: clientHelloID, HandshakeState: handshakeState}
+	uconn := UConn{Conn: &tlsConn, ClientHelloID: clientHelloID, pskExtension: pskExtension, HandshakeState: handshakeState}
 	uconn.HandshakeState.uconn = &uconn
 	uconn.handshakeFn = uconn.clientHandshake
 	return &uconn