gevent SSL with godaddy error: ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:1051)

I've got Webhosting on GoDaddy with their SSL certificate installed.

I'm trying to send the https POST request to my Python backend on my own server (with static IP) which is running gevent WSGIServer like this:

https_server = WSGIServer(('<backend ip>', 3000),
                              appFlask,
                              keyfile='server.key',
                              certfile='server.crt',
                              )

The server.key and server.crt I created by copy/paste from goddady->cPanelAdmin-> Manage SSL Hosts -> Autofill by Domain.

The Certificate: (CRT) -> server.crt. The Private Key (KEY) -> server.key.

The CRT:

The Certificate Authority Bundle:

The client code is React app with hash router where on the button click the following is called:

let res = await axios
      .create({ baseURL: "https://<backend ip>:3000" })
      .post("/server_auth_user", data_obj)
      .then(result => {
        if (result.status === 200 && result.data.response) {
          console.log(result);
          Auth.login(() => {
            this.props.history.push("/screens");
          ...

This is what happens when I run:

openssl s_client -connect <godaddy host>:443 -key 'server.key' -cert 'server.crt'

CONNECTED(00000005)
---
Certificate chain
 0 s:OU = Domain Control Validated, CN = aqts655379k.com
   i:C = US, ST = Arizona, L = Scottsdale, O = "GoDaddy.com, Inc.", OU = http://certs.godaddy.com/repository/, CN = Go Daddy Secure Certificate Authority - G2
 1 s:C = US, ST = Arizona, L = Scottsdale, O = "GoDaddy.com, Inc.", OU = http://certs.godaddy.com/repository/, CN = Go Daddy Secure Certificate Authority - G2
   i:C = US, ST = Arizona, L = Scottsdale, O = "GoDaddy.com, Inc.", CN = Go Daddy Root Certificate Authority - G2
---
Server certificate
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

subject=OU = Domain Control Validated, CN = <godaddy.host>

issuer=C = US, ST = Arizona, L = Scottsdale, O = "GoDaddy.com, Inc.", OU = http://certs.godaddy.com/repository/, CN = Go Daddy Secure Certificate Authority - G2

---
No client certificate CA names sent
Peer signing digest: SHA512
Peer signature type: RSA
Server Temp Key: ECDH, P-256, 256 bits
---
SSL handshake has read 3552 bytes and written 443 bytes
Verification: OK
---
New, TLSv1.2, Cipher is ECDHE-RSA-AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES256-GCM-SHA384
    Session-ID: A1A0E86F59695161F06029EADB6F26C491F01A511A417CCCF07948F095139E3B
    Session-ID-ctx: 
    Master-Key: DAA60D38F7D74D553478FB3B74DE8F7BE315D003FBF3F6847F812CF25693CFC3EDDADB3F4A2A2D278F7239330E156D92
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 300 (seconds)
    TLS session ticket:
    0000 - da 97 5d f6 a9 8a 2d 9b-a0 dd 6f 3c 65 58 11 55   ..]...-...o<eX.U
    0010 - c4 5d 24 c0 f3 03 6d 2e-16 75 9a 6f 9f 29 2d 4e   .]$...m..u.o.)-N
    0020 - 92 98 92 24 27 ab 92 2e-31 7d 83 26 70 ba c8 36   ...$'...1}.&p..6
    0030 - e6 86 62 58 2a e1 8a be-1c 08 d0 a2 30 e6 36 8c   ..bX*.......0.6.
    0040 - be b8 6d 5b 72 37 6b fd-32 f5 16 3b 0b 24 e1 10   ..m[r7k.2..;.$..
    0050 - 2d 71 f5 8d 1f bf d1 5a-74 2b d1 cd 1d ec f1 f9   -q.....Zt+......
    0060 - 6f b3 89 66 10 fa d3 bb-df cc cc 94 fa 61 2b 54   o..f.........a+T
    0070 - 0a 85 ac 0c f5 91 c8 53-06 a4 05 bc a8 bf 18 dc   .......S........
    0080 - 0f cc 71 46 5f af 23 fd-62 48 32 c8 95 20 8f bb   ..qF_.#.bH2.. ..
    0090 - f3 80 aa ca b0 cf 2e 5c-58 84 d9 65 e5 7e 57 a3   .......\X..e.~W.
    00a0 - 09 99 98 72 91 77 21 a1-b9 3e a1 4e 4f 1b af 21   ...r.w!..>.NO..!
    00b0 - ff 02 97 71 90 b6 42 51-04 17 c3 e8 ca 8c 35 f9   ...q..BQ......5.
    00c0 - 33 07 ca 32 2f 9d c1 7e-59 52 37 db e0 c8 fa bf   3..2/..~YR7.....

    Start Time: 1575195127
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no

The strange things are:

on some devices/browsers I manage to go beyond the Submit button but then the redirected page /screens shows not secured, though certificate is valid
on other browsers I see in Python log - as if the godaddy now tries to validate my Python backend certificate?:

ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:1076)
2019-12-01T09:59:25Z <Greenlet at 0x1a8fefe8048: _handle_and_close_when_done(<bound method StreamServer.wrap_socket_and_handle , <bound method StreamServer.do_close of <WSGIServer, (<gevent._socket3.socket [closed]  object, fd=-1, )> failed with SSLError

Solution

openssl s_client -connect <godaddy_host>:80 ...
... ssl3_get_record:wrong version number

You are connecting to the HTTP port (80) not to the HTTPS port (443). No wonder it will fail with the TLS handshake. But this has nothing to do with the error you get in your Python script since I'm pretty sure you don't use port 80 there.

net::ERR_CERT_COMMON_NAME_INVALID

This happens if the subject of the server certificate does not match the hostname you use to access the server in your code. Since nothing about the server certificate and the code of your client is known I cannot be more specific where exactly the problem is.

gevent SSL with godaddy error: ssl.SSLError: [SSL: SSLV3_ALERT_CERTIFICATE_UNKNOWN] sslv3 alert certificate unknown (_ssl.c:1051)

The error message you show in the title is yet another one. This suggests that the server is not accepting the client certificate you use. Note that you cannot use arbitrary certificates as client certificate but must provide the ones accepted by the server.