Extract createServer and parseAuthConfig, simplify programs

Rename createSecureServer to createServer and add an unsecure path
(UA_ServerConfig_setMinimal) when certPath is NULL, eliminating the
if/else server creation blocks in server_lds.c and server_register.c.

Add parseAuthConfig() to common.c to replace four near-identical
authMode parsing blocks across the three programs.

Restructure server_register.c error handling with goto cleanup,
removing ~20 duplicated cleanup sequences.

Rename the CMake library target from DiscoveryCommon to common.

1 files changed, 46 insertions, 171 deletions

diff --git a/src/server_register.c b/src/server_register.c
index cea7124..80bed20 100644
--- a/src/server_register.c
+++ b/src/server_register.c
@@ -2,10 +2,10 @@
  * @file  server_register.c
  * @brief OPC UA Server that registers with a Local Discovery Server.
  *
- * This program runs an OPC UA server configured with security and periodically
- * registers itself with a remote LDS using the RegisterServer2 service. It
- * uses separate certificate pairs for the server and for the client connection
- * to the LDS. On shutdown, it deregisters from the LDS.
+ * This program runs an OPC UA server that periodically registers itself with
+ * a remote LDS using the RegisterServer2 service.  Encryption is optional for
+ * the server; the client connection to the LDS uses a separate certificate
+ * pair.  On shutdown, it deregisters from the LDS.
  */
 
 #include "common.h"
@@ -16,7 +16,6 @@
 #include <open62541/plugin/accesscontrol_default.h>
 #include <open62541/plugin/log_stdout.h>
 #include <open62541/server.h>
-#include <open62541/server_config_default.h>
 
 #include <signal.h>
 #include <stdlib.h>
@@ -66,23 +65,26 @@ main (int argc, char **argv)
 
   /* ── Load server config ─────────────────────────────────────── */
 
-  Config serverCfg;
+  int rc = EXIT_FAILURE;
+  Config serverCfg = { 0 };
+  Config clientCfg = { 0 };
+  char **serverTrustPaths = NULL;
+  size_t serverTrustSize = 0;
+  char **clientTrustPaths = NULL;
+  size_t clientTrustSize = 0;
+  UA_Server *server = NULL;
+
   if (configLoad (argv[1], &serverCfg) != 0)
-    return EXIT_FAILURE;
+    goto cleanup;
 
   int port = configRequireInt (&serverCfg, "port", "ServerRegister");
   const char *applicationUri
       = configRequire (&serverCfg, "applicationUri", "ServerRegister");
   int registerInterval
       = configRequireInt (&serverCfg, "registerInterval", "ServerRegister");
-  const char *serverAuthMode
-      = configRequire (&serverCfg, "authMode", "ServerRegister");
 
-  if (!applicationUri || !serverAuthMode || port < 0 || registerInterval < 0)
-    {
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+  if (!applicationUri || port < 0 || registerInterval < 0)
+    goto cleanup;
 
   /* Security configuration (optional).  When certificate, privateKey, and
      trustStore are all omitted the server runs with SecurityPolicy#None
@@ -99,62 +101,25 @@ main (int argc, char **argv)
                     "Incomplete server security config: certificate, "
                     "privateKey, and trustStore must all be set, or all "
                     "omitted");
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
+      goto cleanup;
     }
 
-  /* Parse server-side auth mode (what clients connecting to this server
-     need).  "anonymous" allows unauthenticated sessions; "user" requires
-     a username/password pair. */
   UA_Boolean serverAllowAnonymous;
   const char *serverUsername = NULL, *serverPassword = NULL;
+  if (parseAuthConfig (&serverCfg, "ServerRegister", &serverAllowAnonymous,
+                       &serverUsername, &serverPassword)
+      != 0)
+    goto cleanup;
 
-  if (strcmp (serverAuthMode, "anonymous") == 0)
-    {
-      serverAllowAnonymous = true;
-    }
-  else if (strcmp (serverAuthMode, "user") == 0)
-    {
-      serverAllowAnonymous = false;
-      serverUsername
-          = configRequire (&serverCfg, "username", "ServerRegister");
-      serverPassword
-          = configRequire (&serverCfg, "password", "ServerRegister");
-      if (!serverUsername || !serverPassword)
-        {
-          configFree (&serverCfg);
-          return EXIT_FAILURE;
-        }
-    }
-  else
-    {
-      UA_LOG_FATAL (UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
-                    "Unknown server auth mode: %s "
-                    "(expected 'anonymous' or 'user')",
-                    serverAuthMode);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
-
-  char **serverTrustPaths = NULL;
-  size_t serverTrustSize = 0;
   if (serverSecure
       && loadTrustStore (serverTrustStore, &serverTrustPaths, &serverTrustSize)
              != 0)
-    {
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+    goto cleanup;
 
   /* ── Load client config ─────────────────────────────────────── */
 
-  Config clientCfg;
   if (configLoad (argv[2], &clientCfg) != 0)
-    {
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+    goto cleanup;
 
   const char *clientAppUri
       = configRequire (&clientCfg, "applicationUri", "ServerRegister");
@@ -166,27 +131,17 @@ main (int argc, char **argv)
       = configRequire (&clientCfg, "securityMode", "ServerRegister");
   const char *securityPolicyStr
       = configRequire (&clientCfg, "securityPolicy", "ServerRegister");
-  const char *clientAuthMode
-      = configRequire (&clientCfg, "authMode", "ServerRegister");
 
   if (!clientAppUri || !clientCertPath || !clientKeyPath || !securityModeStr
-      || !securityPolicyStr || !clientAuthMode)
-    {
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+      || !securityPolicyStr)
+    goto cleanup;
 
   UA_MessageSecurityMode securityMode = parseSecurityMode (securityModeStr);
   if (securityMode == UA_MESSAGESECURITYMODE_INVALID)
     {
       UA_LOG_FATAL (UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
                     "Unknown security mode: %s", securityModeStr);
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
+      goto cleanup;
     }
 
   const char *securityPolicyUri = resolveSecurityPolicyUri (securityPolicyStr);
@@ -194,104 +149,32 @@ main (int argc, char **argv)
     {
       UA_LOG_FATAL (UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
                     "Unknown security policy: %s", securityPolicyStr);
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
+      goto cleanup;
     }
 
-  /* Parse client-side auth mode (how this server authenticates to the
-     LDS when registering). */
   const char *clientUsername = NULL, *clientPassword = NULL;
-
-  if (strcmp (clientAuthMode, "anonymous") == 0)
-    {
-      /* No credentials needed. */
-    }
-  else if (strcmp (clientAuthMode, "user") == 0)
-    {
-      clientUsername
-          = configRequire (&clientCfg, "username", "ServerRegister");
-      clientPassword
-          = configRequire (&clientCfg, "password", "ServerRegister");
-      if (!clientUsername || !clientPassword)
-        {
-          freeTrustStore (serverTrustPaths, serverTrustSize);
-          configFree (&clientCfg);
-          configFree (&serverCfg);
-          return EXIT_FAILURE;
-        }
-    }
-  else
-    {
-      UA_LOG_FATAL (UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
-                    "Unknown client auth mode: %s "
-                    "(expected 'anonymous' or 'user')",
-                    clientAuthMode);
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+  if (parseAuthConfig (&clientCfg, "ServerRegister", NULL, &clientUsername,
+                       &clientPassword)
+      != 0)
+    goto cleanup;
 
   const char *clientTrustStore
       = configRequire (&clientCfg, "trustStore", "ServerRegister");
   if (!clientTrustStore)
-    {
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+    goto cleanup;
 
-  char **clientTrustPaths = NULL;
-  size_t clientTrustSize = 0;
   if (loadTrustStore (clientTrustStore, &clientTrustPaths, &clientTrustSize)
       != 0)
-    {
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
-    }
+    goto cleanup;
 
   /* ── Create and configure server ────────────────────────────── */
 
   UA_StatusCode retval;
-  UA_Server *server;
-
-  if (serverSecure)
-    {
-      server = createSecureServer ((UA_UInt16)port, applicationUri,
-                                   serverCertPath, serverKeyPath,
-                                   serverTrustPaths, serverTrustSize, &retval);
-      if (!server)
-        {
-          freeTrustStore (clientTrustPaths, clientTrustSize);
-          freeTrustStore (serverTrustPaths, serverTrustSize);
-          configFree (&clientCfg);
-          configFree (&serverCfg);
-          return EXIT_FAILURE;
-        }
-    }
-  else
-    {
-      server = UA_Server_new ();
-      UA_ServerConfig *config = UA_Server_getConfig (server);
-      retval = UA_ServerConfig_setMinimal (config, (UA_UInt16)port, NULL);
-      if (retval != UA_STATUSCODE_GOOD)
-        {
-          UA_Server_delete (server);
-          freeTrustStore (clientTrustPaths, clientTrustSize);
-          freeTrustStore (serverTrustPaths, serverTrustSize);
-          configFree (&clientCfg);
-          configFree (&serverCfg);
-          return EXIT_FAILURE;
-        }
-      UA_String_clear (&config->applicationDescription.applicationUri);
-      config->applicationDescription.applicationUri
-          = UA_String_fromChars (applicationUri);
-    }
+  server = createServer ((UA_UInt16)port, applicationUri, serverCertPath,
+                         serverKeyPath, serverTrustPaths, serverTrustSize,
+                         &retval);
+  if (!server)
+    goto cleanup;
 
   UA_ServerConfig *serverConfig = UA_Server_getConfig (server);
   serverConfig->logging->context = (void *)(uintptr_t)logLevel;
@@ -307,14 +190,7 @@ main (int argc, char **argv)
       logins[0].password = UA_STRING ((char *)serverPassword);
       retval = UA_AccessControl_default (serverConfig, false, NULL, 1, logins);
       if (retval != UA_STATUSCODE_GOOD)
-        {
-          UA_Server_delete (server);
-          freeTrustStore (clientTrustPaths, clientTrustSize);
-          freeTrustStore (serverTrustPaths, serverTrustSize);
-          configFree (&clientCfg);
-          configFree (&serverCfg);
-          return EXIT_FAILURE;
-        }
+        goto cleanup;
     }
 
   serverConfig->applicationDescription.applicationType
@@ -334,12 +210,7 @@ main (int argc, char **argv)
   if (retval != UA_STATUSCODE_GOOD)
     {
       UA_Server_run_shutdown (server);
-      UA_Server_delete (server);
-      freeTrustStore (clientTrustPaths, clientTrustSize);
-      freeTrustStore (serverTrustPaths, serverTrustSize);
-      configFree (&clientCfg);
-      configFree (&serverCfg);
-      return EXIT_FAILURE;
+      goto cleanup;
     }
   clientConfig.logging->context = (void *)(uintptr_t)logLevel;
   if (clientUsername)
@@ -412,10 +283,14 @@ main (int argc, char **argv)
     }
 
   UA_Server_run_shutdown (server);
-  UA_Server_delete (server);
+  rc = EXIT_SUCCESS;
+
+cleanup:
+  if (server)
+    UA_Server_delete (server);
   freeTrustStore (clientTrustPaths, clientTrustSize);
   freeTrustStore (serverTrustPaths, serverTrustSize);
   configFree (&clientCfg);
   configFree (&serverCfg);
-  return EXIT_SUCCESS;
+  return rc;
 }