codeql/javascript/ql/lib/semmle/javascript/security/dataflow/BrokenCryptoAlgorithmCustomizations.qll

/**
 * Provides default sources, sinks and sanitizers for reasoning about
 * sensitive information in broken or weak cryptographic algorithms,
 * as well as extension points for adding your own.
 */

import javascript
private import semmle.javascript.security.SensitiveActions

module BrokenCryptoAlgorithm {
  /**
   * A data flow source for sensitive information in broken or weak cryptographic algorithms.
   */
  abstract class Source extends DataFlow::Node {
    /** Gets a string that describes the type of this data flow source. */
    abstract string describe();
  }

  /**
   * A data flow sink for sensitive information in broken or weak cryptographic algorithms.
   */
  abstract class Sink extends DataFlow::Node { }

  /**
   * A sanitizer for sensitive information in broken or weak cryptographic algorithms.
   */
  abstract class Sanitizer extends DataFlow::Node { }

  /**
   * A sensitive expression, viewed as a data flow source for sensitive information
   * in broken or weak cryptographic algorithms.
   */
  class SensitiveExprSource extends Source, DataFlow::ValueNode {
    override SensitiveExpr astNode;

    override string describe() { result = astNode.describe() }
  }

  /**
   * An expression used by a broken or weak cryptographic algorithm.
   */
  class WeakCryptographicOperationSink extends Sink {
    WeakCryptographicOperationSink() {
      exists(CryptographicOperation application |
        application.getAlgorithm().isWeak() and
        this.asExpr() = application.getInput()
      )
    }
  }
}