/**
* Provides a taint-tracking configuration for reasoning about SQL injection vulnerabilities.
*/
import csharp

module SqlInjection {
  import semmle.code.csharp.dataflow.flowsources.Remote
  import semmle.code.csharp.frameworks.Sql
  import semmle.code.csharp.security.Sanitizers

  /**
   * A source specific to SQL injection vulnerabilities.
   */
  abstract class Source extends DataFlow::Node { }

  /**
   * A sink for SQL injection vulnerabilities.
   */
  abstract class Sink extends DataFlow::ExprNode { }

  /**
   * A sanitizer for SQL injection vulnerabilities.
   */
  abstract class Sanitizer extends DataFlow::ExprNode { }

  /**
   * A taint-tracking configuration for SQL injection vulnerabilities.
   */
  class TaintTrackingConfiguration extends TaintTracking::Configuration {
    TaintTrackingConfiguration() {
      this = "SqlInjection"
    }

    override predicate isSource(DataFlow::Node source) {
      source instanceof Source
    }

    override predicate isSink(DataFlow::Node sink) {
      sink instanceof Sink
    }

    override predicate isSanitizer(DataFlow::Node node) {
      node instanceof Sanitizer
    }
  }

  /** A source of remote user input. */
  class RemoteSource extends Source {
    RemoteSource() {
      this instanceof RemoteFlowSource
    }
  }

  /** An SQL expression passed to an API call that executes SQL. */
  class SqlInjectionExprSink extends Sink {
    SqlInjectionExprSink() {
      exists(SqlExpr s | this.getExpr() = s.getSql())
    }
  }

  private class SimpleTypeSanitizer extends Sanitizer, SimpleTypeSanitizedExpr { }

  private class GuidSanitizer extends Sanitizer, GuidSanitizedExpr { }
}
