ERROR: "SSL23_GET_CLIENT_HELLO:unknown protocol" with XCOM loopback for SSL

Products

• XCOM Data Transport
• XCOM Data Transport - Linux PC

Issue/Introduction

Attempting to configure SSL for XCOM r11.6 SP01 on AIX and encountering the following error from a loopback test.
Default configssl.cnf file is being used i.e. SSL_METHOD parameter values are set to all.

XCOMU0780E Txpi  308: TxpiInitSSL Failed msg = <error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol> value = 4294967295:
...
#XCOMU0297E Error requesting header confirmation: Txpi  227: Socket received 0 bytes: partner closed socket. Last error: 0

Environment

• XCOM™ Data Transport®  for AIX 11.6
• XCOM™ Data Transport® for UNIX/Linux PC

Resolution

The loopback configuration file contained the parameter "PORT=8045" to connect to the correct SSL port but did not have parameter "SECURE_SOCKET=YES" set.
The parameter SECURE_SOCKET defaults to NO and is required to be set to YES when using an SSL port/socket.

Additional Information

When inadvertently using the incorrect combination of unsecure port "PORT=8044" with "SECURE_SOCKET=YES" similar errors will be encountered but for SSL23_GET_SERVER_HELLO i.e.

XCOMU0780E Txpi  308: TxpiInitSSL Failed msg = <error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol> value = 4294967295:
...
#XCOMU0298E Unable to allocate remote transaction program: Txpi  215: Socket send error return value = 9