Initial commit: OPC UA discovery project

CMake-based C project using open62541 for OPC UA discovery.
Includes Local Discovery Server, register server, and find
servers client with OpenSSL encryption support.

1 files changed, 280 insertions, 0 deletions

diff --git a/src/common.c b/src/common.c
new file mode 100644
index 0000000..d102868
--- /dev/null
+++ b/src/common.c
@@ -0,0 +1,280 @@
+/**
+ * @file  common.c
+ * @brief Implements shared helpers declared in common.h.
+ */
+
+#include "common.h"
+
+#include <open62541/client_config_default.h>
+#include <open62541/plugin/log_stdout.h>
+#include <open62541/server_config_default.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* ========================================================================
+ * File Loading
+ * ======================================================================== */
+
+UA_ByteString
+loadFile (const char *const path)
+{
+  UA_ByteString fileContents = UA_STRING_NULL;
+
+  FILE *fp = fopen (path, "rb");
+  if (!fp)
+    {
+      /* fopen sets errno on failure.  Callers like createSecureServer use
+         loadFile for optional trustlist entries where a missing file is not
+         an error.  Clear errno so open62541's logging does not pick up
+         a stale value and emit misleading error messages. */
+      errno = 0;
+      return fileContents;
+    }
+
+  fseek (fp, 0, SEEK_END);
+  fileContents.length = (size_t)ftell (fp);
+  fileContents.data
+      = (UA_Byte *)UA_malloc (fileContents.length * sizeof (UA_Byte));
+  if (fileContents.data)
+    {
+      fseek (fp, 0, SEEK_SET);
+      size_t read = fread (fileContents.data, sizeof (UA_Byte),
+                           fileContents.length, fp);
+      if (read != fileContents.length)
+        UA_ByteString_clear (&fileContents);
+    }
+  else
+    {
+      fileContents.length = 0;
+    }
+  fclose (fp);
+
+  return fileContents;
+}
+
+/* ========================================================================
+ * Security Helpers
+ * ======================================================================== */
+
+UA_MessageSecurityMode
+parseSecurityMode (const char *name)
+{
+  if (strcmp (name, "None") == 0)
+    return UA_MESSAGESECURITYMODE_NONE;
+  if (strcmp (name, "Sign") == 0)
+    return UA_MESSAGESECURITYMODE_SIGN;
+  if (strcmp (name, "SignAndEncrypt") == 0)
+    return UA_MESSAGESECURITYMODE_SIGNANDENCRYPT;
+  return UA_MESSAGESECURITYMODE_INVALID;
+}
+
+const char *
+resolveSecurityPolicyUri (const char *shortName)
+{
+  static const struct
+  {
+    const char *name;
+    const char *uri;
+  } policies[] = {
+    { "None", "http://opcfoundation.org/UA/SecurityPolicy#None" },
+    { "Basic256Sha256",
+      "http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256" },
+    { "Aes256_Sha256_RsaPss",
+      "http://opcfoundation.org/UA/SecurityPolicy#Aes256_Sha256_RsaPss" },
+    { "Aes128_Sha256_RsaOaep",
+      "http://opcfoundation.org/UA/SecurityPolicy#Aes128_Sha256_RsaOaep" },
+    { "ECC_nistP256",
+      "http://opcfoundation.org/UA/SecurityPolicy#ECC_nistP256" },
+  };
+  for (size_t i = 0; i < sizeof (policies) / sizeof (policies[0]); i++)
+    {
+      if (strcmp (shortName, policies[i].name) == 0)
+        return policies[i].uri;
+    }
+  return NULL;
+}
+
+/* ========================================================================
+ * Output Formatting
+ * ======================================================================== */
+
+void
+printApplicationDescription (const UA_ApplicationDescription *description,
+                             size_t index)
+{
+  const char *type = "Unknown";
+  switch (description->applicationType)
+    {
+    case UA_APPLICATIONTYPE_SERVER:
+      type = "Server";
+      break;
+    case UA_APPLICATIONTYPE_CLIENT:
+      type = "Client";
+      break;
+    case UA_APPLICATIONTYPE_CLIENTANDSERVER:
+      type = "Client and Server";
+      break;
+    case UA_APPLICATIONTYPE_DISCOVERYSERVER:
+      type = "Discovery Server";
+      break;
+    default:
+      break;
+    }
+
+  UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION, "Server[%lu]: %.*s",
+               (unsigned long)index, (int)description->applicationUri.length,
+               description->applicationUri.data);
+  UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION, "  Name: %.*s",
+               (int)description->applicationName.text.length,
+               description->applicationName.text.data);
+  UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION,
+               "  Application URI: %.*s",
+               (int)description->applicationUri.length,
+               description->applicationUri.data);
+  UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION,
+               "  Product URI: %.*s", (int)description->productUri.length,
+               description->productUri.data);
+  UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION, "  Type: %s", type);
+  for (size_t j = 0; j < description->discoveryUrlsSize; j++)
+    {
+      UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION,
+                   "  Discovery URL[%lu]: %.*s", (unsigned long)j,
+                   (int)description->discoveryUrls[j].length,
+                   description->discoveryUrls[j].data);
+    }
+}
+
+void
+printEndpoint (const UA_EndpointDescription *endpoint, size_t index)
+{
+  const char *mode = "Unknown";
+  switch (endpoint->securityMode)
+    {
+    case UA_MESSAGESECURITYMODE_NONE:
+      mode = "None";
+      break;
+    case UA_MESSAGESECURITYMODE_SIGN:
+      mode = "Sign";
+      break;
+    case UA_MESSAGESECURITYMODE_SIGNANDENCRYPT:
+      mode = "SignAndEncrypt";
+      break;
+    default:
+      break;
+    }
+
+  /* Extract policy name after the '#' */
+  const char *policy = (const char *)endpoint->securityPolicyUri.data;
+  size_t policyLen = endpoint->securityPolicyUri.length;
+  for (size_t k = 0; k < endpoint->securityPolicyUri.length; k++)
+    {
+      if (endpoint->securityPolicyUri.data[k] == '#')
+        {
+          policy = (const char *)&endpoint->securityPolicyUri.data[k + 1];
+          policyLen = endpoint->securityPolicyUri.length - k - 1;
+          break;
+        }
+    }
+
+  UA_LOG_INFO (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION,
+               "  [%4lu] %.*s | Level: %2d | %-14s | %.*s",
+               (unsigned long)index, (int)endpoint->endpointUrl.length,
+               endpoint->endpointUrl.data, endpoint->securityLevel, mode,
+               (int)policyLen, policy);
+}
+
+/* ========================================================================
+ * Factory Functions
+ * ======================================================================== */
+
+UA_Server *
+createSecureServer (UA_UInt16 port, const char *applicationUri,
+                    const char *certPath, const char *keyPath,
+                    char **trustPaths, size_t trustSize, UA_StatusCode *retval)
+{
+  UA_ByteString certificate = loadFile (certPath);
+  UA_ByteString privateKey = loadFile (keyPath);
+
+  /* +1: UA_STACKARRAY requires a strictly positive size for VLA. */
+  UA_STACKARRAY (UA_ByteString, trustList, trustSize + 1);
+  for (size_t i = 0; i < trustSize; i++)
+    trustList[i] = loadFile (trustPaths[i]);
+
+  /* Issuer and revocation lists are unused in this demo. */
+  size_t issuerListSize = 0;
+  UA_ByteString *issuerList = NULL;
+  UA_ByteString *revocationList = NULL;
+  size_t revocationListSize = 0;
+
+  UA_Server *server = UA_Server_new ();
+  UA_ServerConfig *config = UA_Server_getConfig (server);
+
+  *retval = UA_ServerConfig_setDefaultWithSecurityPolicies (
+      config, port, &certificate, &privateKey, trustList, trustSize,
+      issuerList, issuerListSize, revocationList, revocationListSize);
+
+  UA_ByteString_clear (&certificate);
+  UA_ByteString_clear (&privateKey);
+  for (size_t i = 0; i < trustSize; i++)
+    UA_ByteString_clear (&trustList[i]);
+
+  if (*retval != UA_STATUSCODE_GOOD)
+    {
+      UA_Server_delete (server);
+      return NULL;
+    }
+
+  UA_String_clear (&config->applicationDescription.applicationUri);
+  config->applicationDescription.applicationUri
+      = UA_String_fromChars (applicationUri);
+
+  return server;
+}
+
+UA_StatusCode
+createSecureClientConfig (UA_ClientConfig *cc, const char *applicationUri,
+                          const char *certPath, const char *keyPath,
+                          char **trustPaths, size_t trustSize,
+                          UA_MessageSecurityMode securityMode,
+                          const char *securityPolicyUri)
+{
+  UA_ByteString certificate = loadFile (certPath);
+  UA_ByteString privateKey = loadFile (keyPath);
+
+  /* +1: UA_STACKARRAY requires a strictly positive size for VLA. */
+  UA_STACKARRAY (UA_ByteString, trustList, trustSize + 1);
+  for (size_t i = 0; i < trustSize; i++)
+    trustList[i] = loadFile (trustPaths[i]);
+
+  /* Revocation list is unused in this demo. */
+  UA_ByteString *revocationList = NULL;
+  size_t revocationListSize = 0;
+
+  UA_StatusCode retval = UA_ClientConfig_setDefaultEncryption (
+      cc, certificate, privateKey, trustList, trustSize, revocationList,
+      revocationListSize);
+
+  UA_ByteString_clear (&certificate);
+  UA_ByteString_clear (&privateKey);
+  for (size_t i = 0; i < trustSize; i++)
+    UA_ByteString_clear (&trustList[i]);
+
+  if (retval != UA_STATUSCODE_GOOD)
+    {
+      UA_LOG_ERROR (UA_Log_Stdout, UA_LOGCATEGORY_APPLICATION,
+                    "Failed to set client encryption. StatusCode %s",
+                    UA_StatusCode_name (retval));
+      return retval;
+    }
+
+  UA_String_clear (&cc->clientDescription.applicationUri);
+  cc->clientDescription.applicationUri = UA_String_fromChars (applicationUri);
+
+  cc->securityMode = securityMode;
+  cc->securityPolicyUri = UA_String_fromChars (securityPolicyUri);
+
+  return retval;
+}