diff options
Diffstat (limited to 'libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/BufferedBlockCipher.java')
| -rw-r--r-- | libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/BufferedBlockCipher.java | 313 |
1 files changed, 0 insertions, 313 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/BufferedBlockCipher.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/BufferedBlockCipher.java deleted file mode 100644 index 941943322..000000000 --- a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/BufferedBlockCipher.java +++ /dev/null @@ -1,313 +0,0 @@ -package org.spongycastle.crypto; - - -/** - * A wrapper class that allows block ciphers to be used to process data in - * a piecemeal fashion. The BufferedBlockCipher outputs a block only when the - * buffer is full and more data is being added, or on a doFinal. - * <p> - * Note: in the case where the underlying cipher is either a CFB cipher or an - * OFB one the last block may not be a multiple of the block size. - */ -public class BufferedBlockCipher -{ - protected byte[] buf; - protected int bufOff; - - protected boolean forEncryption; - protected BlockCipher cipher; - - protected boolean partialBlockOkay; - protected boolean pgpCFB; - - /** - * constructor for subclasses - */ - protected BufferedBlockCipher() - { - } - - /** - * Create a buffered block cipher without padding. - * - * @param cipher the underlying block cipher this buffering object wraps. - */ - public BufferedBlockCipher( - BlockCipher cipher) - { - this.cipher = cipher; - - buf = new byte[cipher.getBlockSize()]; - bufOff = 0; - - // - // check if we can handle partial blocks on doFinal. - // - String name = cipher.getAlgorithmName(); - int idx = name.indexOf('/') + 1; - - pgpCFB = (idx > 0 && name.startsWith("PGP", idx)); - - if (pgpCFB) - { - partialBlockOkay = true; - } - else - { - partialBlockOkay = (idx > 0 && (name.startsWith("CFB", idx) || name.startsWith("GCFB", idx) ||name.startsWith("OFB", idx) || name.startsWith("OpenPGP", idx) || name.startsWith("SIC", idx) || name.startsWith("GCTR", idx))); - } - } - - /** - * return the cipher this object wraps. - * - * @return the cipher this object wraps. - */ - public BlockCipher getUnderlyingCipher() - { - return cipher; - } - - /** - * initialise the cipher. - * - * @param forEncryption if true the cipher is initialised for - * encryption, if false for decryption. - * @param params the key and other data required by the cipher. - * @exception IllegalArgumentException if the params argument is - * inappropriate. - */ - public void init( - boolean forEncryption, - CipherParameters params) - throws IllegalArgumentException - { - this.forEncryption = forEncryption; - - reset(); - - cipher.init(forEncryption, params); - } - - /** - * return the blocksize for the underlying cipher. - * - * @return the blocksize for the underlying cipher. - */ - public int getBlockSize() - { - return cipher.getBlockSize(); - } - - /** - * return the size of the output buffer required for an update - * an input of len bytes. - * - * @param len the length of the input. - * @return the space required to accommodate a call to update - * with len bytes of input. - */ - public int getUpdateOutputSize( - int len) - { - int total = len + bufOff; - int leftOver; - - if (pgpCFB) - { - leftOver = total % buf.length - (cipher.getBlockSize() + 2); - } - else - { - leftOver = total % buf.length; - } - - return total - leftOver; - } - - /** - * return the size of the output buffer required for an update plus a - * doFinal with an input of 'length' bytes. - * - * @param length the length of the input. - * @return the space required to accommodate a call to update and doFinal - * with 'length' bytes of input. - */ - public int getOutputSize( - int length) - { - // Note: Can assume partialBlockOkay is true for purposes of this calculation - return length + bufOff; - } - - /** - * process a single byte, producing an output block if neccessary. - * - * @param in the input byte. - * @param out the space for any output that might be produced. - * @param outOff the offset from which the output will be copied. - * @return the number of output bytes copied to out. - * @exception DataLengthException if there isn't enough space in out. - * @exception IllegalStateException if the cipher isn't initialised. - */ - public int processByte( - byte in, - byte[] out, - int outOff) - throws DataLengthException, IllegalStateException - { - int resultLen = 0; - - buf[bufOff++] = in; - - if (bufOff == buf.length) - { - resultLen = cipher.processBlock(buf, 0, out, outOff); - bufOff = 0; - } - - return resultLen; - } - - /** - * process an array of bytes, producing output if necessary. - * - * @param in the input byte array. - * @param inOff the offset at which the input data starts. - * @param len the number of bytes to be copied out of the input array. - * @param out the space for any output that might be produced. - * @param outOff the offset from which the output will be copied. - * @return the number of output bytes copied to out. - * @exception DataLengthException if there isn't enough space in out. - * @exception IllegalStateException if the cipher isn't initialised. - */ - public int processBytes( - byte[] in, - int inOff, - int len, - byte[] out, - int outOff) - throws DataLengthException, IllegalStateException - { - if (len < 0) - { - throw new IllegalArgumentException("Can't have a negative input length!"); - } - - int blockSize = getBlockSize(); - int length = getUpdateOutputSize(len); - - if (length > 0) - { - if ((outOff + length) > out.length) - { - throw new OutputLengthException("output buffer too short"); - } - } - - int resultLen = 0; - int gapLen = buf.length - bufOff; - - if (len > gapLen) - { - System.arraycopy(in, inOff, buf, bufOff, gapLen); - - resultLen += cipher.processBlock(buf, 0, out, outOff); - - bufOff = 0; - len -= gapLen; - inOff += gapLen; - - while (len > buf.length) - { - resultLen += cipher.processBlock(in, inOff, out, outOff + resultLen); - - len -= blockSize; - inOff += blockSize; - } - } - - System.arraycopy(in, inOff, buf, bufOff, len); - - bufOff += len; - - if (bufOff == buf.length) - { - resultLen += cipher.processBlock(buf, 0, out, outOff + resultLen); - bufOff = 0; - } - - return resultLen; - } - - /** - * Process the last block in the buffer. - * - * @param out the array the block currently being held is copied into. - * @param outOff the offset at which the copying starts. - * @return the number of output bytes copied to out. - * @exception DataLengthException if there is insufficient space in out for - * the output, or the input is not block size aligned and should be. - * @exception IllegalStateException if the underlying cipher is not - * initialised. - * @exception InvalidCipherTextException if padding is expected and not found. - * @exception DataLengthException if the input is not block size - * aligned. - */ - public int doFinal( - byte[] out, - int outOff) - throws DataLengthException, IllegalStateException, InvalidCipherTextException - { - try - { - int resultLen = 0; - - if (outOff + bufOff > out.length) - { - throw new OutputLengthException("output buffer too short for doFinal()"); - } - - if (bufOff != 0) - { - if (!partialBlockOkay) - { - throw new DataLengthException("data not block size aligned"); - } - - cipher.processBlock(buf, 0, buf, 0); - resultLen = bufOff; - bufOff = 0; - System.arraycopy(buf, 0, out, outOff, resultLen); - } - - return resultLen; - } - finally - { - reset(); - } - } - - /** - * Reset the buffer and cipher. After resetting the object is in the same - * state as it was after the last init (if there was one). - */ - public void reset() - { - // - // clean the buffer. - // - for (int i = 0; i < buf.length; i++) - { - buf[i] = 0; - } - - bufOff = 0; - - // - // reset the underlying cipher. - // - cipher.reset(); - } -} |