ICipherParams interface

Declaration

package com.kryptel.cipher;

public interface ICipherParams {
    int GetKeySize() throws Exception;
    int GetRounds() throws Exception;
    byte GetScheme() throws Exception;
    byte[] GetKey() throws Exception;

    void SetKeySize(int size) throws Exception;
    void SetRounds(int rounds) throws Exception;
    void SetScheme(byte scheme) throws Exception;
    void SetKey(byte[] key, int start, int size) throws Exception;
	
    CipherInfo GetInfo() throws Exception;
}

Description

This interface sets and obtains parameters of a given cipher (stream or block one). See also its extension IBlockCipherParams interface for block cipher-specific parameters.

GetInfo

CipherInfo GetInfo() throws Exception;

Returns the CipherInfo structure describing the cipher.

GetKey

byte[] GetKey() throws Exception;

Returns the currently set encryption key. Note that unlike IBlockCipherParams.GetInitVector, this method returns the user-specified key, not the normalized version. So the length of the returned array is not necessarily equals the set key size.

GetKeySize

int GetKeySize() throws Exception;

Returns the currently set key size in bytes.

GetRounds

int GetRounds() throws Exception;

Returns the currently set number of rounds.

GetScheme

byte GetScheme() throws Exception;

Returns the currently selected cipher scheme. Some ciphers exist in several variations, for instance, Triple-DES works either as encrypt-encrypt-encrypt or as encrypt-decrypt-encrypt sequence. The scheme number designates the variation to be used.

SetKey

void SetKey(byte[] key, int start, int size) throws Exception;

Set encryption key. If size is not equal to the currently set key size, the key is normalized – either truncated or padded with zero bytes.

SetKeySize

void SetKeySize(int size) throws Exception;

Set cipher's key size in bytes. The size value must be a valid key size from the CipherInfo.ValidKeySizes list. DEFAULT_VALUE resets the key size to the default value.

SetRounds

void SetRounds(int rounds) throws Exception;

Set the number of ciphering rounds. The value must be one from the CipherInfo.ValidRounds list, or DEFAULT_VALUE to reset the number of rounds to the default value.

SetScheme

void SetScheme(byte scheme) throws Exception;

Select a cipher variation (scheme). The scheme number must be in the range from 1 to N, where N is the number of available schemes. DEFAULT_VALUE selects the cipher's default scheme.