feature: rework guardrails

data/source/guardrails/env.c

@@ -1,29 +1,46 @@
 
+char my_tolower(char c) {
+    if (c >= 'A' && c <= 'Z') {
+        return c + ('a' - 'A');  // or return c + 32;
+    }
+    return c;
+}
 
-int mystrcmp(wchar_t* str1, wchar_t* str2) {
-	int i = 0;
-	while (str1[i] != L'\0' && str2[i] != L'\0') {
-		if (str1[i] != str2[i]) {
-			return 1;
-		}
-		i++;
-	}
-	return 0;
+// Returns 1 if 'needle' is found in 'haystack' (case-insensitive), 0 otherwise
+int contains_case_insensitive(const char* haystack, const char* needle) {
+    if (!haystack || !needle)
+        return 0;
+
+    for (; *haystack; haystack++) {
+        const char* h = haystack;
+        const char* n = needle;
+
+        while (*h && *n && my_tolower((unsigned char)*h) == my_tolower((unsigned char)*n)) {
+            h++;
+            n++;
+        }
+
+        if (*n == '\0') {
+            return 1;  // Match found
+        }
+    }
+
+    return 0;  // No match
 }
 
 
 int executionguardrail() {
-	// Execution Guardrail: Env Check
-	wchar_t envVarName[] = L"USERPROFILE";
-	wchar_t tocheck[] = L"{{guardrail_data}}";
-	WCHAR buffer[1024];  // NOTE: Do not make it bigger, or we have a __chkstack() dependency!
-	DWORD result = GetEnvironmentVariableW(envVarName, buffer, 1024);
-	if (result == 0) {
-		return 6;
-	}
-	if (mystrcmp(buffer, tocheck) != 0) { 
-		return 6;
-	}
+    // Execution Guardrail: Env Check
+    LPCSTR envVarName = "{{guardrail_data_key}}";
+    LPCSTR tocheck = "{{guardrail_data_value}}";
+    char buffer[1024];  // NOTE: Do not make it bigger, or we have a __chkstack() dependency!
+    DWORD result = GetEnvironmentVariableA(envVarName, buffer, 1024);
+    if (result == 0) {
+        return 6;
+    }
+    if (! contains_case_insensitive(buffer, tocheck)) {
+        return 6;
+    }
     return 0;
 }