# Package org.apache.tomcat.util.security

- Interface Summary
  Interface | Description
  --- | ---
  PermissionCheck | This interface is implemented by components to enable privileged code to check whether the component has a given permission.

- Class Summary
  Class | Description
  --- | ---
  ConcurrentMessageDigest | A thread safe wrapper around `MessageDigest` that does not make use of ThreadLocal and - broadly - only creates enough MessageDigest objects to satisfy the concurrency requirements.
  Escape | Provides utility methods to escape content for different contexts.
  KeyStoreUtil |
  MD5Encoder | Encode an MD5 digest into a String.
  PrivilegedGetTccl |
  PrivilegedSetAccessControlContext |
  PrivilegedSetTccl |