remote error: tls: missing extension

[uoosef]

hello when im using this code from example folder to implement a simple doh client and accessing this host https://dns.rotunneling.net/dns-query/public

utlsConn := tls.UClient(plainConn, config, tls.HelloCustom)
    spec := tls.ClientHelloSpec{
        TLSVersMax: tls.VersionTLS13,
        TLSVersMin: tls.VersionTLS10,
        CipherSuites: []uint16{
            tls.GREASE_PLACEHOLDER,
            tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
            tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
            tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
            tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
            tls.TLS_AES_128_GCM_SHA256, // tls 1.3
            tls.FAKE_TLS_DHE_RSA_WITH_AES_256_CBC_SHA,
            tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
            tls.TLS_RSA_WITH_AES_256_CBC_SHA,
        },
        Extensions: []tls.TLSExtension{
            &tls.SNIExtension{},
            &tls.SupportedCurvesExtension{Curves: []tls.CurveID{tls.X25519, tls.CurveP256}},
            &tls.SupportedPointsExtension{SupportedPoints: []byte{0}}, // uncompressed
            &tls.SessionTicketExtension{},
            &tls.ALPNExtension{AlpnProtocols: []string{"myFancyProtocol", "http/1.1"}},
            &tls.SignatureAlgorithmsExtension{SupportedSignatureAlgorithms: []tls.SignatureScheme{
                tls.ECDSAWithP256AndSHA256,
                tls.ECDSAWithP384AndSHA384,
                tls.ECDSAWithP521AndSHA512,
                tls.PSSWithSHA256,
                tls.PSSWithSHA384,
                tls.PSSWithSHA512,
                tls.PKCS1WithSHA256,
                tls.PKCS1WithSHA384,
                tls.PKCS1WithSHA512,
                tls.ECDSAWithSHA1,
                tls.PKCS1WithSHA1}},
            &tls.KeyShareExtension{KeyShares: []tls.KeyShare{
                {Group: tls.CurveID(tls.GREASE_PLACEHOLDER), Data: []byte{0}},
                {Group: tls.X25519},
            }},
            &tls.PSKKeyExchangeModesExtension{Modes: []uint8{1}}, // pskModeDHE
            &tls.SupportedVersionsExtension{Versions: []uint16{
                tls.VersionTLS13,
                tls.VersionTLS12,
                tls.VersionTLS11,
                tls.VersionTLS10}},
        },
        GetSessionID: nil,
    }
    err := utlsConn.ApplyPreset(&spec)

    if err != nil {
        return nil, fmt.Errorf("uTlsConn.Handshake() error: %+v", err)
    }

    return utlsConn, nil

i get this error

 Get \"https://dns.rotunneling.net/dns-query/public?dns=AAABAAABAAAAAAAAA3d3dwZnb29nbGUDY29tAAABAAE\": remote error: tls: missing extension

how can i fix this issue ?

[gaukas]

Have you tried using any of the existing parrots from u_parrot.go? It is hard to know which extension is missing from your ClientHelloSpec since it is a general remote error.

[gaukas]

Well, I guess here's some general advice for debugging:

1. Locate from which line does the error come from
2. Capture at least one ClientHello from any other client which DOES work
3. Check the difference in between

If anyone ever encounter the same issue.

[uoosef]

My bad, I forget to call

err = uTlsConn.Handshake()

after setting custom spec, its intersting that it works on some sites without directly calling the handshake for exapmle it works on cloudflare without calling the handshake!

[gaukas]

Hmm. Can you double check with wireshark or tcpdump? Sounds like something related to #75.

[gaukas]

Just check if the ClientHello message got sent is the one you expected or not when you don't explicitly call .Handshake().