org.bouncycastle.crypto
Interface SkippingCipher

All Known Subinterfaces:

CTRModeCipher, SkippingStreamCipher

All Known Implementing Classes:

Salsa20Engine, SICBlockCipher

public interface SkippingCipher

Ciphers producing a key stream which can be reset to particular points in the stream implement this.

Method Summary

long	getPosition() Return the current "position" of the cipher
long	seekTo(long position) Reset the cipher and then skip forward to a given position.
long	skip(long numberOfBytes) Skip numberOfBytes forwards, or backwards.

Method Detail

skip

public long skip(long numberOfBytes)

Skip numberOfBytes forwards, or backwards.

Parameters:

numberOfBytes - the number of bytes to skip (positive forward, negative backwards).

Returns:

the number of bytes actually skipped.

Throws:

java.lang.IllegalArgumentException - if numberOfBytes is an invalid value.

seekTo

public long seekTo(long position)

Reset the cipher and then skip forward to a given position.

Parameters:

position - the number of bytes in to set the cipher state to.

Returns:

the byte position moved to.

getPosition

public long getPosition()

Return the current "position" of the cipher

Returns:

the current byte position.