### Description

Some users are having issues connecting to kamailio websocket using TLS. The logs show SSLv3 errors. Cannot find why that error would show up if SSLv2/3 is not enabled. Double checked it via SSLLabs that only TLSv1.2 is allowed in the service.

Any pointers would be appreciated. Also, let me know if more debug information is needed.

### Troubleshooting

#### Debugging Data

This is the TLS config:

``` modparam("tls", "tls_method", "TLSv1.2+") modparam("tls", "verify_certificate", 0) modparam("tls", "require_certificate", 0) modparam("tls", "low_mem_threshold1", 0) modparam("tls", "low_mem_threshold2", 0) modparam("tls", "private_key", "/etc/certs/tls.key") modparam("tls", "certificate", "/etc/certs/tls.crt") ```

This is the output from tls module in kamcmd: ``` kamcmd> tls.info { max_connections: 2048 opened_connections: 353 clear_text_write_queued_bytes: 0 } kamcmd> tls.options { force_run: 0 method: TLSv1.2+ verify_certificate: 0 verify_depth: 9 require_certificate: 0 private_key: /etc/certs/tls.key ca_list: <null string> certificate: /etc/certs/tls.crt cipher_list: <null string> session_cache: 0 session_id: kamailio-tls-5.x.y config: <null string> log: 3 debug: 3 connection_timeout: 600 disable_compression: 1 ssl_release_buffers: -1 ssl_freelist_max: -1 ssl_max_send_fragment: -1 ssl_read_ahead: 0 send_close_notify: 0 low_mem_threshold1: 0 low_mem_threshold2: 0 ct_wq_max: 10485760 con_ct_wq_max: 65536 ct_wq_blk_size: 4096 } ```

#### Log Messages

I see this log messages related to SSLv3:

``` 15(36) ERROR: tls [tls_util.h:42]: tls_err_ret(): TLS accept:error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown 15(36) ERROR: <core> [core/tcp_read.c:1512]: tcp_read_req(): ERROR: tcp_read_req: error reading - c: 0x7fafc8768190 r: 0x7fafc8768278 (-1) ```

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` version: kamailio 5.3.9 (x86_64/linux) flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled with gcc 6.3.0 ```

* **Operating System**:

Debian 9.13.

``` Linux 4.19.112+ #1 SMP Wed Sep 23 07:53:39 PDT 2020 x86_64 GNU/Linux ```