/**
* Initializes this cipher with a key and a source of randomness. The cipher is initialized for
* one of the following four operations: encryption, decryption, key wrapping or key unwrapping,
* depending on the value of <code>opmode</code>.
*
* <p>If this cipher (including its underlying feedback or padding scheme) requires any random
* bytes, it will get them from <code>random</code>.
*
* @param opmode the operation mode of this cipher (this is one of the following: <code>
* ENCRYPT_MODE</code>, <code>DECRYPT_MODE</code>), <code>WRAP_MODE</code> or <code>
* UNWRAP_MODE</code>)
* @param key the encryption key
* @param random the source of randomness
* @exception InvalidKeyException if the given key is inappropriate for initializing this cipher
*/
protected void engineInit(int opmode, Key key, SecureRandom random) throws InvalidKeyException {
try {
core.init(opmode, key, (AlgorithmParameterSpec) null, random);
} catch (InvalidAlgorithmParameterException ie) {
InvalidKeyException ike = new InvalidKeyException("requires PBE parameters");
ike.initCause(ie);
throw ike;
}
}
/**
* Returns the block size (in bytes).
*
* @return the block size (in bytes)
*/
protected int engineGetBlockSize() {
return core.getBlockSize();
}
/**
* Unwrap a previously wrapped key.
*
* @param wrappedKey the key to be unwrapped.
* @param wrappedKeyAlgorithm the algorithm the wrapped key is for.
* @param wrappedKeyType the type of the wrapped key. This is one of <code>Cipher.SECRET_KEY
* </code>, <code>Cipher.PRIVATE_KEY</code>, or <code>Cipher.PUBLIC_KEY</code>.
* @return the unwrapped key.
* @exception NoSuchAlgorithmException if no installed providers can create keys of type <code>
* wrappedKeyType</code> for the <code>wrappedKeyAlgorithm</code>.
* @exception InvalidKeyException if <code>wrappedKey</code> does not represent a wrapped key of
* type <code>wrappedKeyType</code> for the <code>wrappedKeyAlgorithm</code>.
*/
protected Key engineUnwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, int wrappedKeyType)
throws InvalidKeyException, NoSuchAlgorithmException {
return core.unwrap(wrappedKey, wrappedKeyAlgorithm, wrappedKeyType);
}
/**
* Wrap a key.
*
* @param key the key to be wrapped.
* @return the wrapped key.
* @exception IllegalBlockSizeException if this cipher is a block cipher, no padding has been
* requested, and the length of the encoding of the key to be wrapped is not a multiple of the
* block size.
* @exception InvalidKeyException if it is impossible or unsafe to wrap the key with this cipher
* (e.g., a hardware protected key is being passed to a software only cipher).
*/
protected byte[] engineWrap(Key key) throws IllegalBlockSizeException, InvalidKeyException {
return core.wrap(key);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
* The data is encrypted or decrypted, depending on how this cipher was initialized.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code> buffer, starting at <code>
* inputOffset</code>, and any input bytes that may have been buffered during a previous <code>
* update</code> operation, are processed, with padding (if requested) being applied. The result
* is stored in the <code>output</code> buffer, starting at <code>outputOffset</code>.
*
* <p>The cipher is reset to its initial state (uninitialized) after this call.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input starts
* @param inputLen the input length
* @param output the buffer for the result
* @param outputOffset the offset in <code>output</code> where the result is stored
* @return the number of bytes stored in <code>output</code>
* @exception 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
* @exception ShortBufferException if the given output buffer is too small to hold the result
* @exception BadPaddingException if decrypting and padding is choosen, but the last input data
* does not have proper padding bytes.
*/
protected int engineDoFinal(
byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)
throws ShortBufferException, IllegalBlockSizeException, BadPaddingException {
return core.doFinal(input, inputOffset, inputLen, output, outputOffset);
}
/**
* Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
* The data is encrypted or decrypted, depending on how this cipher was initialized.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code> buffer, starting at <code>
* inputOffset</code>, and any input bytes that may have been buffered during a previous <code>
* update</code> operation, are processed, with padding (if requested) being applied. The result
* is stored in a new buffer.
*
* <p>The cipher is reset to its initial state (uninitialized) after this call.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input starts
* @param inputLen the input length
* @return the new buffer with the result
* @exception 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
* @exception BadPaddingException if decrypting and padding is choosen, but the last input data
* does not have proper padding bytes.
*/
protected byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen)
throws IllegalBlockSizeException, BadPaddingException {
return core.doFinal(input, inputOffset, inputLen);
}
/**
* Continues a multiple-part encryption or decryption operation (depending on how this cipher was
* initialized), processing another data part.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code> buffer, starting at <code>
* inputOffset</code>, are processed, and the result is stored in the <code>output</code> buffer,
* starting at <code>outputOffset</code>.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input starts
* @param inputLen the input length
* @param output the buffer for the result
* @param outputOffset the offset in <code>output</code> where the result is stored
* @return the number of bytes stored in <code>output</code>
* @exception ShortBufferException if the given output buffer is too small to hold the result
*/
protected int engineUpdate(
byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)
throws ShortBufferException {
return core.update(input, inputOffset, inputLen, output, outputOffset);
}
/**
* Continues a multiple-part encryption or decryption operation (depending on how this cipher was
* initialized), processing another data part.
*
* <p>The first <code>inputLen</code> bytes in the <code>input</code> buffer, starting at <code>
* inputOffset</code>, are processed, and the result is stored in a new buffer.
*
* @param input the input buffer
* @param inputOffset the offset in <code>input</code> where the input starts
* @param inputLen the input length
* @return the new buffer with the result
*/
protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen) {
return core.update(input, inputOffset, inputLen);
}
protected void engineInit(int opmode, Key key, AlgorithmParameters params, SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
core.init(opmode, key, params, random);
}
/**
* Returns the parameters used with this cipher.
*
* <p>The returned parameters may be the same that were used to initialize this cipher, or may
* contain the default set of parameters or a set of randomly generated parameters used by the
* underlying cipher implementation (provided that the underlying cipher implementation uses a
* default set of parameters or creates new parameters if it needs parameters but was not
* initialized with any).
*
* @return the parameters used with this cipher, or null if this cipher does not use any
* parameters.
*/
protected AlgorithmParameters engineGetParameters() {
return core.getParameters();
}
/**
* Returns the initialization vector (IV) in a new buffer.
*
* <p>This is useful in the case where a random IV has been created (see <a href =
* "#init">init</a>), or in the context of password-based encryption or decryption, where the IV
* is derived from a user-supplied password.
*
* @return the initialization vector in a new buffer, or null if the underlying algorithm does not
* use an IV, or if the IV has not yet been set.
*/
protected byte[] engineGetIV() {
return core.getIV();
}
/**
* Returns the length in bytes that an output buffer would need to be in order to hold the result
* of the next <code>update</code> or <code>doFinal</code> operation, given the input length
* <code>inputLen</code> (in bytes).
*
* <p>This call takes into account any unprocessed (buffered) data from a previous <code>update
* </code> call, and padding.
*
* <p>The actual output length of the next <code>update</code> or <code>doFinal</code> call may be
* smaller than the length returned by this method.
*
* @param inputLen the input length (in bytes)
* @return the required output buffer size (in bytes)
*/
protected int engineGetOutputSize(int inputLen) {
return core.getOutputSize(inputLen);
}