Class GuardedString


  • public final class GuardedString
    extends java.lang.Object
    Secure string implementation that solves the problems associated with keeping passwords as java.lang.String. That is, anything represented as a String is kept in memory as a clear text password and stays in memory at least until it is garbage collected.

    The GuardedString class alleviates this problem by storing the characters in memory in an encrypted form. The encryption key will be a randomly-generated key.

    In their serialized form, GuardedString will be encrypted using a known default key. This is to provide a minimum level of protection regardless of the transport. For communications with the Remote Connector Framework it is recommended that deployments enable SSL for true encryption.

    Applications may also wish to persist GuardedStrings. In the case of Identity Manager, it should convert GuardedStrings to EncryptedData so that they can be stored and managed using the Manage Encryption features of Identity Manager. Other applications may wish to serialize APIConfiguration as a whole. These applications are responsible for encrypting the APIConfiguration blob for an additional layer of security (beyond the basic default key encryption provided by GuardedString).

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static interface  GuardedString.Accessor
      Callback interface for those times that it is necessary to access the clear text of the secure string.
    • Constructor Summary

      Constructors 
      Constructor Description
      GuardedString()
      Creates an empty secure string
      GuardedString​(char[] clearChars)
      Initialized the GuardedString from the given clear characters.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void access​(GuardedString.Accessor accessor)
      Provides access to the clear-text value of the string in a controlled fashion.
      void appendChar​(char c)
      Appends a single clear-text character to the secure string.
      GuardedString copy()
      Create a copy of the string.
      void dispose()
      Clears the in-memory representation of the string.
      boolean equals​(java.lang.Object o)  
      int hashCode()  
      boolean isReadOnly()
      Returns true if this string has been marked read-only.
      void makeReadOnly()
      Mark this string as read-only.
      boolean verifyBase64SHA1Hash​(java.lang.String hash)
      Verifies that this base-64 encoded SHA1 hash of this string matches the given value.
      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • GuardedString

        public GuardedString()
        Creates an empty secure string
      • GuardedString

        public GuardedString​(char[] clearChars)
        Initialized the GuardedString from the given clear characters. Caller is responsible for zeroing out the array of characters after the call.
        Parameters:
        clearChars - The clear-text characters
    • Method Detail

      • access

        public void access​(GuardedString.Accessor accessor)
        Provides access to the clear-text value of the string in a controlled fashion. The clear-text characters will only be available for the duration of the call and automatically zeroed out following the call.

        NOTE: Callers are encouraged to use verifyBase64SHA1Hash(String) where possible if the intended use is merely to verify the contents of the string match an expected hash value.

        Parameters:
        accessor - Accessor callback.
        Throws:
        java.lang.IllegalStateException - If the string has been disposed
      • appendChar

        public void appendChar​(char c)
        Appends a single clear-text character to the secure string. The in-memory data will be decrypted, the character will be appended, and then it will be re-encrypted.
        Parameters:
        c - The character to append.
        Throws:
        java.lang.IllegalStateException - If the string is read-only
        java.lang.IllegalStateException - If the string has been disposed
      • dispose

        public void dispose()
        Clears the in-memory representation of the string.
      • isReadOnly

        public boolean isReadOnly()
        Returns true if this string has been marked read-only.
        Returns:
        true if this string has been marked read-only.
        Throws:
        java.lang.IllegalStateException - If the string has been disposed
      • makeReadOnly

        public void makeReadOnly()
        Mark this string as read-only.
        Throws:
        java.lang.IllegalStateException - If the string has been disposed
      • copy

        public GuardedString copy()
        Create a copy of the string. If this instance is read-only, the copy will not be read-only.
        Returns:
        A copy of the string.
        Throws:
        java.lang.IllegalStateException - If the string has been disposed
      • verifyBase64SHA1Hash

        public boolean verifyBase64SHA1Hash​(java.lang.String hash)
        Verifies that this base-64 encoded SHA1 hash of this string matches the given value.
        Parameters:
        hash - The hash to verify against.
        Returns:
        True if the hash matches the given parameter.
        Throws:
        java.lang.IllegalStateException - If the string has been disposed
      • equals

        public boolean equals​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object