de.schlichtherle.truezip.crypto.raes
Class Type0RaesReadOnlyFile

java.lang.Object
  de.schlichtherle.truezip.rof.AbstractReadOnlyFile
      de.schlichtherle.truezip.rof.DecoratingReadOnlyFile
          de.schlichtherle.truezip.crypto.CipherReadOnlyFile
              de.schlichtherle.truezip.crypto.raes.RaesReadOnlyFile
                  de.schlichtherle.truezip.crypto.raes.Type0RaesReadOnlyFile

All Implemented Interfaces:

ReadOnlyFile, Closeable

@NotThreadSafe
@DefaultAnnotation(value=edu.umd.cs.findbugs.annotations.NonNull.class)
 class Type0RaesReadOnlyFile
extends RaesReadOnlyFile

Reads a type 0 RAES file.

Author:

Christian Schlichtherle

MIN_KEY_RETRY_DELAY

private static final long MIN_KEY_RETRY_DELAY

The minimum delay between subsequent attempts to authenticate a key in milliseconds.

See Also:

Constant Field Values

keyStrength

private final Type0RaesParameters.KeyStrength keyStrength

The key strength.

macParam

private final CipherParameters macParam

The parameters required to init the Message Authentication Code (MAC).

footer

private final byte[] footer

The footer of the data envelope containing the authentication codes.

Type0RaesReadOnlyFile

Type0RaesReadOnlyFile(ReadOnlyFile rof,
                      Type0RaesParameters param)
                throws IOException

Throws:

IOException

enforceSuspensionPenalty

private static long enforceSuspensionPenalty(long last)

getKeyStrength

public Type0RaesParameters.KeyStrength getKeyStrength()

Description copied from class: RaesReadOnlyFile

Returns the key strength which is actually used to decrypt the data of the RAES file.

Specified by:

getKeyStrength in class RaesReadOnlyFile

authenticate

public void authenticate()
                  throws RaesAuthenticationException,
                         IOException

Description copied from class: RaesReadOnlyFile

Authenticates all encrypted data in the read only file. It is safe to call this method multiple times to detect if the file has been tampered with meanwhile.

This is the second, optional step of authentication. The first, mandatory step is to computeMac the cipher key and cipher text length only and has already been successfully completed in the constructor.

Specified by:

authenticate in class RaesReadOnlyFile

Throws:

RaesAuthenticationException - If the computed MAC does not match the MAC declared in the RAES file.

IOException - On any I/O related issue.