Cloak/libcloak/client/browsers/browser.go

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2022-07-11 21:25:42 +00:00
package browsers
import "encoding/binary"
type ClientHelloFields struct {
Random []byte
SessionId []byte
X25519KeyShare []byte
ServerName string
}
// Browser represents the signature of a browser at a particular version
type Browser interface {
// ComposeClientHello produces the ClientHello message (without TLS record layer) as the mimicking browser would
ComposeClientHello(ClientHelloFields) []byte
}
// addExtensionRecord, add type, length to extension data
func addExtRec(typ []byte, data []byte) []byte {
length := make([]byte, 2)
binary.BigEndian.PutUint16(length, uint16(len(data)))
ret := make([]byte, 2+2+len(data))
copy(ret[0:2], typ)
copy(ret[2:4], length)
copy(ret[4:], data)
return ret
}
func generateSNI(serverName string) []byte {
serverNameListLength := make([]byte, 2)
binary.BigEndian.PutUint16(serverNameListLength, uint16(len(serverName)+3))
serverNameType := []byte{0x00} // host_name
serverNameLength := make([]byte, 2)
binary.BigEndian.PutUint16(serverNameLength, uint16(len(serverName)))
ret := make([]byte, 2+1+2+len(serverName))
copy(ret[0:2], serverNameListLength)
copy(ret[2:3], serverNameType)
copy(ret[3:5], serverNameLength)
copy(ret[5:], serverName)
return ret
}