/**
 * @name Input Validation Scanner - CodeQL Ruleset
 * @description This ruleset contains queries that identify potential input validation vulnerabilities.
 * @kind meta-ruleset
 * @id input-validation-scanner
 */

import javascript
import python
import go
import csharp
import java
import cpp

/**
 *  General Input Validation Checks
 */

// Untrusted data used in SQL queries (SQL Injection)
from SqlInjectionQuery q
select q, "Potential SQL Injection vulnerability: Untrusted data used in SQL query."

// Untrusted data used in OS commands (Command Injection)
from CommandInjectionQuery q
select q, "Potential Command Injection vulnerability: Untrusted data used in OS command."

// Untrusted data used in XPath queries (XPath Injection) - Requires XPath support in language
// from XPathInjectionQuery q
// select q, "Potential XPath Injection vulnerability: Untrusted data used in XPath query."

// Cross-Site Scripting (XSS) - Requires framework-specific queries for best results
// Placeholder: Add XSS queries here, potentially framework-specific (e.g., React, Angular, Vue)

/**
 * Language-Specific Input Validation Checks
 */

// JavaScript/TypeScript examples
from DataFlow::PathGraph<DataFlow::Node, DataFlow::Node> path, DataFlow::Configuration cfg, DataFlow::Node source, DataFlow::Node sink
where cfg.hasFlowPath(source, sink) and
      source.asExpr().(CallExpr).getCalleeName() = "eval" and //Example: Detect use of eval with untrusted input.  This is just an example, adjust as needed.
      sink.asExpr().(CallExpr).getArgument(0).toString().regexpMatch(".*[<>&\"'].*") and // Example: Simple check for HTML characters in the eval input.  This is just an example, adjust as needed.
      source.asExpr().(CallExpr).getArgument(0).toString().regexpMatch(".*userInput.*") // Example:  Check if the eval input uses a variable named "userInput".  This is just an example, adjust as needed.
select path, "Potential JavaScript eval with untrusted input."

// Python examples
// Placeholder: Add Python-specific input validation queries here, focusing on common vulnerabilities. Example: OS Command Injection through format strings.

// Go examples
// Placeholder: Add Go-specific input validation queries here, focusing on common vulnerabilities. Example: Path Traversal.

// C# examples
// Placeholder: Add C#-specific input validation queries here, focusing on common vulnerabilities. Example: LDAP Injection.

// Java examples
// Placeholder: Add Java-specific input validation queries here, focusing on common vulnerabilities. Example: Deserialization vulnerabilities.

// C/C++ examples
// Placeholder: Add C/C++-specific input validation queries here, focusing on common vulnerabilities. Example: Buffer overflows.

/**
 *  Custom Input Validation Checks
 *
 *  Placeholder:  Add custom queries tailored to the specific application or framework.
 *  These queries should focus on identifying missing or inadequate input validation routines.
 */

// Example: Check for missing length validation on a specific input field.
// from DataFlow::PathGraph<DataFlow::Node, DataFlow::Node> path, DataFlow::Configuration cfg, DataFlow::Node source, DataFlow::Node sink
// where cfg.hasFlowPath(source, sink) and
//       source.asExpr().(VariableAccess).getTarget().getName() = "userInput" and // Replace "userInput" with the actual input field name
//       sink.asExpr().(CallExpr).getCalleeName() = "processData" and // Replace "processData" with the function that processes the input
//       not exists(CallExpr call | call.getCalleeName() = "validateLength" and call.getArgument(0) = source.asExpr()) // Check for missing length validation
// select path, "Missing length validation for input field 'userInput'."

/**
 *  Helper Queries (Optional)
 *
 *  Placeholder: Add helper queries that can be used by other queries in this ruleset.
 *  These can simplify the main queries and improve code reuse.
 */

/**
 *  Configuration
 *
 *  Placeholder: Add any necessary configuration options for the queries in this ruleset.
 *  This might include specifying trusted sources, sanitization functions, or regular expressions.
 */

/**
 *  Considerations
 *
 *  - This ruleset is a starting point and should be customized to the specific application and its security requirements.
 *  - Regularly update the ruleset to address new vulnerabilities and attack vectors.
 *  - Review the results carefully and prioritize remediation based on the severity of the vulnerability and the likelihood of exploitation.
 */