Replace ClientFindServers with unified Client, use trust store directories

Replace the single-purpose ClientFindServers program with a unified Client
that supports three operations via CLI: find-servers, get-endpoints, and
read-time.  This simplifies the architecture by using one client binary with
a single config file instead of a monolithic program that did everything in
one run.

Split the ServerRegister config into separate server and client config files
so the LDS-registration credentials are isolated from the server's own
settings.  The discovery URL moves from config to a CLI argument.

Replace repeated trustList config entries with a single trustStore directory
path.  Each program now points to a directory under certs/trust/ containing
.der files, so adding or removing trust is a file-copy operation rather than
editing every config file.  Add loadTrustStore()/freeTrustStore() to
common.c and remove the now-unused configGetAll() from the config parser.

Simplify the test matrix from 6 to 4 cases (security and auth are
orthogonal, so the full 3x2 matrix is unnecessary).  Update run_test.sh to
invoke the new Client three times and use port-polling instead of sleep.

1 files changed, 8 insertions, 10 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f126d30..ab6f4fd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,8 +4,7 @@
 #
 # Builds three programs that demonstrate OPC UA discovery. ServerLDS runs a
 # Local Discovery Server.  ServerRegister periodically registers itself with the
-# LDS.  ClientFindServers queries the LDS for registered servers and their
-# endpoints.
+# LDS.  Client queries servers for discovery info, endpoints, or current time.
 #
 # All programs link against DiscoveryCommon (shared helpers and config parser)
 # which in turn depends on open62541.
@@ -27,9 +26,9 @@ include(cmake/BuildDeps.cmake)
 add_library(DiscoveryCommon STATIC src/common.c src/config.c)
 target_link_libraries(DiscoveryCommon open62541::open62541)
 
-# Queries the LDS for registered servers and their endpoints.
-add_executable(ClientFindServers src/client_find_servers.c)
-target_link_libraries(ClientFindServers DiscoveryCommon)
+# Unified client: find-servers, get-endpoints, read-time.
+add_executable(Client src/client.c)
+target_link_libraries(Client DiscoveryCommon)
 
 # Runs the Local Discovery Server that other servers register with.
 add_executable(ServerLDS src/server_lds.c)
@@ -61,17 +60,16 @@ endif()
 # Each test exercises a combination of security mode/policy and authentication
 # method.  _test_names and _test_policies are parallel lists: the Nth name uses
 # the Nth policy.  Each name corresponds to a config directory under tests/
-# containing server_lds.conf, server_register.conf, client_find_servers.conf.
+# containing server_lds.conf, server_register.conf, server_register_client.conf,
+# client.conf.
 
 enable_testing()
 
 set(_test_script "${CMAKE_SOURCE_DIR}/tests/run_test.sh")
 
-set(_test_names none_anon none_user basic256sha256_anon basic256sha256_user
-                aes128_anon aes128_user)
+set(_test_names none_anon none_user basic256sha256_anon aes128_user)
 
-set(_test_policies None None Basic256Sha256 Basic256Sha256
-                   Aes128_Sha256_RsaOaep Aes128_Sha256_RsaOaep)
+set(_test_policies None None Basic256Sha256 Aes128_Sha256_RsaOaep)
 
 foreach(_name _policy IN ZIP_LISTS _test_names _test_policies)
   add_test(NAME "${_name}" COMMAND bash "${_test_script}" "tests/${_name}"