proxy.py: [Ubuntu] Cannot use TLS interception

Describe the bug Iam not able to use the TLS interception feature, as provided in the readme section. Even the basic

To Reproduce Steps to reproduce the behavior:

1. [Host machine] Install proxy==2.1.2 pip install proxy.py
2. [Host machine] create ssl files

export CA_KEY_FILE_PATH=ca-key.pem
export CA_CERT_FILE_PATH=ca-cert.pem
export CA_SIGNING_KEY_FILE_PATH=ca-signing-key.pem
python -m proxy.common.pki gen_private_key --private-key-path $CA_KEY_FILE_PATH
python -m proxy.common.pki remove_passphrase --private-key-path $CA_KEY_FILE_PATH
python -m proxy.common.pki gen_public_key --private-key-path $CA_KEY_FILE_PATH --public-key-path $CA_CERT_FILE_PATH
python -m proxy.common.pki gen_private_key --private-key-path $CA_SIGNING_KEY_FILE_PATH
python -m proxy.common.pki remove_passphrase --private-key-path

1. [Host machine] Run proxy.py

$ proxy --plugins proxy.plugin.CacheResponsesPlugin --ca-key-file ca-key.pem --ca-cert-file ca-cert.pem --ca-signing-key-file ca-signing-key.pem --host 0.0.0.0 --log-level d
2020-03-02 11:11:41,970 - pid:20523 [I] load_plugins:525 - Loaded plugin proxy.http.proxy.HttpProxyPlugin
2020-03-02 11:11:41,971 - pid:20523 [I] load_plugins:525 - Loaded plugin proxy.plugin.CacheResponsesPlugin
2020-03-02 11:11:41,972 - pid:20523 [I] listen:63 - Listening on 0.0.0.0:8899
2020-03-02 11:11:41,975 - pid:20523 [D] start_workers:81 - Started acceptor#0 process 20525
2020-03-02 11:11:41,976 - pid:20523 [I] start_workers:84 - Started 1 workers

1. [Client machine] Send request from client system

$ curl --proxy http://host_ip:8899 --cacert ~/work/varnish_docker_virtual/squid_docker/upstream_haproxy_certs/haproxy-ca-cert.pem https://httpbin.org/ip -vvv
*   Trying host_ip...
* TCP_NODELAY set
* Connected to host_ip (host_ip) port 8899 (#0)
* allocate connect buffer!
* Establish HTTP proxy tunnel to httpbin.org:443
> CONNECT httpbin.org:443 HTTP/1.1
> Host: httpbin.org:443
> User-Agent: curl/7.58.0
> Proxy-Connection: Keep-Alive
> 
< HTTP/1.1 200 Connection established
< 
* Proxy replied 200 to CONNECT request
* CONNECT phase completed!
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
*   CAfile: /home/jitesh/work/varnish_docker_virtual/squid_docker/upstream_haproxy_certs/haproxy-ca-cert.pem
  CApath: /etc/ssl/certs
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* CONNECT phase completed!
* CONNECT phase completed!
* OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to httpbin.org:443 
* stopped the pause stream!
* Closing connection 0
curl: (35) OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to httpbin.org:443 

1. [Host machine] Check error log at the host

2020-03-02 11:11:47,320 - pid:20525 [D] initialize:145 - Handling connection <socket.socket fd=9, family=AddressFamily.AF_INET, type=2049, proto=0, laddr=('host_ip', 8899), raddr=('gateway_ip/client_ip', 19673)>
2020-03-02 11:11:47,322 - pid:20525 [D] handle_readables:302 - Client is ready for reads, reading
2020-03-02 11:11:47,322 - pid:20525 [D] recv:65 - received 114 bytes from client
2020-03-02 11:11:47,324 - pid:20525 [D] connect_upstream:420 - Connecting to upstream httpbin.org:443
2020-03-02 11:11:47,363 - pid:20525 [D] connect_upstream:425 - Connected to upstream httpbin.org:443
2020-03-02 11:11:47,402 - pid:20525 [D] generate_upstream_certificate:362 - Generating certificates /home/ubuntu/.proxy.py/certificates/httpbin.org.pem
2020-03-02 11:11:47,422 - pid:20525 [D] flush:91 - flushed 39 bytes to client
2020-03-02 11:11:47,423 - pid:20525 [E] on_request_complete:278 - OSError when wrapping client
2020-03-02 11:11:47,423 - pid:20525 [I] access_log:332 - gateway_ip/client_ip:19673 - CONNECT httpbin.org:443 - 0 bytes - 105.42 ms
2020-03-02 11:11:47,424 - pid:20525 [I] close:48 - Cached response at /tmp/httpbin.org-89311d71dce24450b200947c9ef8ac1f.txt
2020-03-02 11:11:47,424 - pid:20525 [D] on_client_connection_close:189 - Closed server connection, has buffer False
2020-03-02 11:11:47,424 - pid:20525 [D] shutdown:217 - Closing client connection <socket.socket fd=9, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('host_ip', 8899), raddr=('gateway_ip/client_ip', 19673)> at address ('gateway_ip/client_ip', 19673) has buffer False
2020-03-02 11:11:47,425 - pid:20525 [D] shutdown:225 - Client connection shutdown successful
2020-03-02 11:11:47,425 - pid:20525 [D] shutdown:230 - Client connection closed

Expected behavior The expected outcome of https://github.com/abhinavsingh/proxy.py#tls-interception

Version information

• OS: Ubuntu 18.04.4 LTS (GNU/Linux 4.15.0-88-generic x86_64)
• Curl: curl 7.58.0 (x86_64-pc-linux-gnu) libcurl/7.58.0 OpenSSL/1.1.1 zlib/1.2.11 libidn2/2.0.4 libpsl/0.19.1 (+libidn2/2.0.4) nghttp2/1.30.0 librtmp/2.3
• proxy.py Version 2.1.2

Additional context I am able to get response of http://httpbin.org/ip without any issues. So the problem only occurs at the HTTPS section. Do let me know if there are any procedures that I missed.