com.cafesoft.core.crypto
Interface SymmetricCipher

All Known Implementing Classes:

SecretKeyCipher

public interface SymmetricCipher

SymmetricCipher defines an interface for encrypting and decrypting data based on symmetric algorithms. Implementations may use a secret key, public/private key, etc. as required.

Method Summary

byte[]	decrypt(byte[] input) Decrypts data in a single-part operation.
int	decrypt(byte[] input, int inputLen, byte[] output) Decrypts data in a single-part operation.
byte[]	encrypt(byte[] input) Encrypts data in a single-part operation.
int	encrypt(byte[] input, int inputLen, byte[] output) Encrypts data in a single-part operation.

Method Detail

encrypt

public byte[] encrypt(byte[] input)
               throws IllegalStateException,
                      IllegalBlockSizeException,
                      BadPaddingException

Encrypts data in a single-part operation.

The bytes in the input buffer are processed and padded if necessary. The result is stored in a new buffer.

Parameters:

input - the input buffer

Returns:

the new buffer with the result

Throws:

IllegalStateException - if this cipher is in a wrong state (e.g., has not been initialized)

IllegalBlockSizeException - - if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size

BadPaddingException - if the internal encryption cipher has and invalid padding configuration or has an error while padding data.

encrypt

public int encrypt(byte[] input,
                   int inputLen,
                   byte[] output)
            throws IllegalStateException,
                   IllegalBlockSizeException,
                   ShortBufferException,
                   BadPaddingException

Encrypts data in a single-part operation.

The specified number of bytes in the input buffer are processed and padded if necessary. The result is stored in the specified output buffer. NOTE: this method should be used in preference to methods that return new byte buffers when multiple encrptions must be performed within the scope of a calling method. This enables reuse of the output buffer for returned encrypted cipher text.

Parameters:

input - the input buffer (the clear text)

inputLen - the number of bytes to be read from the input buffer

output - the output buffer (for storing cipher text)

Returns:

the number of byte written to the output buffer or 0 if no bytes encrypted.

Throws:

IllegalStateException - if this cipher is in a wrong state (e.g., has not been initialized)

ShortBufferException - if the given output buffer is too small to hold the result

IllegalBlockSizeException - - if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size

BadPaddingException - if the internal encryption cipher has and invalid padding configuration or has an error while padding data.

decrypt

public byte[] decrypt(byte[] input)
               throws IllegalStateException,
                      IllegalBlockSizeException,
                      BadPaddingException

Decrypts data in a single-part operation.

The bytes in the input buffer are processed and padding that was added at encryption time is removed. The result is stored in a new buffer.

Parameters:

input - the input buffer

Returns:

the new buffer with the result

Throws:

IllegalStateException - if this cipher is in a wrong state (e.g., has not been initialized)

IllegalBlockSizeException - - if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size

BadPaddingException - if the internal encryption cipher has and invalid padding configuration or has an error while padding data.

decrypt

public int decrypt(byte[] input,
                   int inputLen,
                   byte[] output)
            throws IllegalStateException,
                   IllegalBlockSizeException,
                   ShortBufferException,
                   BadPaddingException

Decrypts data in a single-part operation.

The specified number of bytes in the input buffer are processed and padding is removed. The result is stored in the specified output buffer. NOTE: this method should be used in preference to methods that return new byte buffers when multiple decryptions must be performed within the scope of a calling method. This enables reuse of the output buffer for returned decrypted clear text.

Parameters:

input - the input buffer (the cipher text)

inputLen - the number of bytes to be read from the input buffer

output - the output buffer (for storing clear text)

Returns:

the number of byte written to the output buffer or 0 if no bytes encrypted.

Throws:

IllegalStateException - if this cipher is in a wrong state (e.g., has not been initialized)

ShortBufferException - if the given output buffer is too small to hold the result

IllegalBlockSizeException - - if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size

BadPaddingException - if the internal encryption cipher has and invalid padding configuration or has an error while padding data.