256c61ee90fe805f

// import tls "github.com/refraction-networking/utls"
tcpConn, err := net.Dial("tcp", "tlsfingerprint.io:443")
if err != nil {
	fmt.Printf("net.Dial() failed: %+v\n", err)
	return
}

config := tls.Config{ServerName: "tlsfingerprint.io"}
// This fingerprint includes feature(s), not fully supported by TLS.
// uTLS client with this fingerprint will only be able to to talk to servers,
// that also do not support those features. 
tlsConn := tls.Client(tcpConn, &tlsConfig, utls.HelloCustom)
clientHelloSpec := tls.ClientHelloSpec {
	CipherSuites: []uint16{
		tls.GREASE_PLACEHOLDER,
		tls.TLS_AES_128_GCM_SHA256,
		tls.TLS_AES_256_GCM_SHA384,
		tls.TLS_CHACHA20_POLY1305_SHA256,
		tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
		tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
		tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
		tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
		tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
		tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
		tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
		tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
	},
	CompressionMethods: []byte{
		0x00, // compressionNone
	},
	Extensions: []tls.TLSExtension{
		&tls.UtlsGREASEExtension{},
		&tls.SNIExtension{},
		&tls.UtlsExtendedMasterSecretExtension{},
		&tls.RenegotiationInfoExtension{renegotiation: tls.RenegotiateOnceAsClient},
		&tls.SupportedCurvesExtension{[]tls.CurveID{
			tls.CurveID(tls.GREASE_PLACEHOLDER),
			tls.X25519,
			tls.CurveP256,
			tls.CurveP384,
		}},
		&tls.SupportedPointsExtension{SupportedPoints: []byte{
			0x00, // pointFormatUncompressed
		}},
		&tls.SessionTicketExtension{},
		&tls.ALPNExtension{AlpnProtocols: []string{"h2","http/1.1"}},
		&tls.StatusRequestExtension{},
		&tls.SignatureAlgorithmsExtension{SupportedSignatureAlgorithms: []SignatureScheme{
			tls.ECDSAWithP256AndSHA256,
			tls.PSSWithSHA256,
			tls.PKCS1WithSHA256,
			tls.ECDSAWithP384AndSHA384,
			tls.PSSWithSHA384,
			tls.PKCS1WithSHA384,
			tls.PSSWithSHA512,
			tls.PKCS1WithSHA512,
		},},
		&tls.SCTExtension{},
		&tls.KeyShareExtension{[]tls.KeyShare{
			{Group: tls.CurveID(tls.GREASE_PLACEHOLDER), Data: []byte{0}},
			{Group: tls.X25519},
		}},
		&tls.PSKKeyExchangeModesExtension{[]uint8{
			tls.PskModeDHE,
		}},
		&tls.SupportedVersionsExtension{[]uint16{
			tls.GREASE_PLACEHOLDER,
			tls.VersionTLS13,
			tls.VersionTLS12,
			tls.VersionTLS11,
			tls.VersionTLS10,
		}},
		&tls.FakeCertCompressionAlgsExtension{[]tls.CertCompressionAlgo{
			tls.CertCompressionBrotli,
		}},
		&tls.GenericExtension {id: 0x4469}, // WARNING: UNKNOWN EXTENSION, USE AT YOUR OWN RISK
		&tls.UtlsGREASEExtension{},
		&tls.GenericExtension {id: 0x0029}, // WARNING: UNKNOWN EXTENSION, USE AT YOUR OWN RISK
	},
}
tlsConn.ApplyPreset(clientHelloSpec)
        
n, err = tlsConn.Write("Hello, World!")
// or tlsConn.Handshake() for better control