mirror of https://github.com/cbeuw/Cloak
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
107 lines
4.4 KiB
Go
107 lines
4.4 KiB
Go
// Fingerprint of Chrome 99
|
|
|
|
package client
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"encoding/hex"
|
|
|
|
"github.com/cbeuw/Cloak/internal/common"
|
|
)
|
|
|
|
type Chrome struct{}
|
|
|
|
func makeGREASE() []byte {
|
|
// see https://tools.ietf.org/html/draft-davidben-tls-grease-01
|
|
// This is exclusive to Chrome.
|
|
var one [1]byte
|
|
common.CryptoRandRead(one[:])
|
|
sixteenth := one[0] % 16
|
|
monoGREASE := sixteenth*16 + 0xA
|
|
doubleGREASE := []byte{monoGREASE, monoGREASE}
|
|
return doubleGREASE
|
|
}
|
|
|
|
func (c *Chrome) composeExtensions(serverName string, keyShare []byte) []byte {
|
|
|
|
makeSupportedGroups := func() []byte {
|
|
suppGroupListLen := []byte{0x00, 0x08}
|
|
ret := make([]byte, 2+8)
|
|
copy(ret[0:2], suppGroupListLen)
|
|
copy(ret[2:4], makeGREASE())
|
|
copy(ret[4:], []byte{0x00, 0x1d, 0x00, 0x17, 0x00, 0x18})
|
|
return ret
|
|
}
|
|
|
|
makeKeyShare := func(hidden []byte) []byte {
|
|
ret := make([]byte, 43)
|
|
ret[0], ret[1] = 0x00, 0x29 // length 41
|
|
copy(ret[2:4], makeGREASE())
|
|
ret[4], ret[5] = 0x00, 0x01 // length 1
|
|
ret[6] = 0x00
|
|
ret[7], ret[8] = 0x00, 0x1d // group x25519
|
|
ret[9], ret[10] = 0x00, 0x20 // length 32
|
|
copy(ret[11:43], hidden)
|
|
return ret
|
|
}
|
|
|
|
// extension length is always 403, and server name length is variable
|
|
|
|
var ext [18][]byte
|
|
ext[0] = addExtRec(makeGREASE(), nil) // First GREASE
|
|
ext[1] = addExtRec([]byte{0x00, 0x00}, generateSNI(serverName)) // server name indication
|
|
ext[2] = addExtRec([]byte{0x00, 0x17}, nil) // extended_master_secret
|
|
ext[3] = addExtRec([]byte{0xff, 0x01}, []byte{0x00}) // renegotiation_info
|
|
ext[4] = addExtRec([]byte{0x00, 0x0a}, makeSupportedGroups()) // supported groups
|
|
ext[5] = addExtRec([]byte{0x00, 0x0b}, []byte{0x01, 0x00}) // ec point formats
|
|
ext[6] = addExtRec([]byte{0x00, 0x23}, nil) // Session tickets
|
|
ALPN, _ := hex.DecodeString("000c02683208687474702f312e31")
|
|
ext[7] = addExtRec([]byte{0x00, 0x10}, ALPN) // app layer proto negotiation
|
|
ext[8] = addExtRec([]byte{0x00, 0x05}, []byte{0x01, 0x00, 0x00, 0x00, 0x00}) // status request
|
|
sigAlgo, _ := hex.DecodeString("001004030804040105030805050108060601")
|
|
ext[9] = addExtRec([]byte{0x00, 0x0d}, sigAlgo) // Signature Algorithms
|
|
ext[10] = addExtRec([]byte{0x00, 0x12}, nil) // signed cert timestamp
|
|
ext[11] = addExtRec([]byte{0x00, 0x33}, makeKeyShare(keyShare)) // key share
|
|
ext[12] = addExtRec([]byte{0x00, 0x2d}, []byte{0x01, 0x01}) // psk key exchange modes
|
|
suppVersions, _ := hex.DecodeString("069A9A03040303") // 9A9A needs to be a GREASE
|
|
copy(suppVersions[1:3], makeGREASE())
|
|
ext[13] = addExtRec([]byte{0x00, 0x2b}, suppVersions) // supported versions
|
|
ext[14] = addExtRec([]byte{0x00, 0x1b}, []byte{0x02, 0x00, 0x02}) // compress certificate
|
|
applicationSettings, _ := hex.DecodeString("0003026832")
|
|
ext[15] = addExtRec([]byte{0x44, 0x69}, applicationSettings) // application settings
|
|
ext[16] = addExtRec(makeGREASE(), []byte{0x00}) // Last GREASE
|
|
// len(ext[1]) + 175 + len(ext[16]) = 403
|
|
// len(ext[16]) = 228 - len(ext[1])
|
|
// 2+2+len(padding) = 228 - len(ext[1])
|
|
// len(padding) = 224 - len(ext[1])
|
|
ext[17] = addExtRec([]byte{0x00, 0x15}, make([]byte, 224-len(ext[1]))) // padding
|
|
var ret []byte
|
|
for _, e := range ext {
|
|
ret = append(ret, e...)
|
|
}
|
|
return ret
|
|
}
|
|
|
|
func (c *Chrome) composeClientHello(hd clientHelloFields) (ch []byte) {
|
|
var clientHello [12][]byte
|
|
clientHello[0] = []byte{0x01} // handshake type
|
|
clientHello[1] = []byte{0x00, 0x01, 0xfc} // length 508
|
|
clientHello[2] = []byte{0x03, 0x03} // client version
|
|
clientHello[3] = hd.random // random
|
|
clientHello[4] = []byte{0x20} // session id length 32
|
|
clientHello[5] = hd.sessionId // session id
|
|
clientHello[6] = []byte{0x00, 0x20} // cipher suites length 32
|
|
cipherSuites, _ := hex.DecodeString("130113021303c02bc02fc02cc030cca9cca8c013c014009c009d002f0035")
|
|
clientHello[7] = append(makeGREASE(), cipherSuites...) // cipher suites
|
|
clientHello[8] = []byte{0x01} // compression methods length 1
|
|
clientHello[9] = []byte{0x00} // compression methods
|
|
clientHello[11] = c.composeExtensions(hd.serverName, hd.x25519KeyShare)
|
|
clientHello[10] = []byte{0x00, 0x00} // extensions length 403
|
|
binary.BigEndian.PutUint16(clientHello[10], uint16(len(clientHello[11])))
|
|
var ret []byte
|
|
for _, c := range clientHello {
|
|
ret = append(ret, c...)
|
|
}
|
|
return ret
|
|
}
|