feature: enhance ssl.get_shared_ssl_ciphers() for stream

[chensunny]

Summy

This pull request introduces a new feature to retrieve shared SSL ciphers in the ngx_stream_lua_module and includes corresponding tests. The main changes involve adding a new FFI function, updating the Lua API, and implementing a new test case to validate the feature.

Related PR

Closed #505
openresty/lua-nginx-module#1962
openresty/lua-nginx-module#2424
openresty/stream-lua-nginx-module#378

New Feature: Shared SSL Ciphers Retrieval

• FFI Function Addition:

  • Added a new FFI function ngx_stream_lua_ffi_req_shared_ssl_ciphers in lib/ngx/ssl.lua to retrieve shared SSL ciphers. This function includes an option to filter GREASE values.

• Lua API Update:

  • Exposed the new FFI function as ngx_lua_ffi_req_shared_ssl_ciphers in the Lua API for the ngx_stream_lua_module.

Testing Enhancements

• Test Plan Update:

  • Increased the planned test count in t/stream/ssl.t to accommodate the new test case.

• New Test Case:

  • Added a comprehensive test case (TEST 29) in t/stream/ssl.t to validate the retrieval of shared SSL ciphers. This test ensures the function works correctly by logging the shared cipher IDs and verifying the output in the error log.