diff options
Diffstat (limited to 'libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/OldCTSBlockCipher.java')
| -rw-r--r-- | libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/OldCTSBlockCipher.java | 269 |
1 files changed, 0 insertions, 269 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/OldCTSBlockCipher.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/OldCTSBlockCipher.java deleted file mode 100644 index 30402b55f..000000000 --- a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/OldCTSBlockCipher.java +++ /dev/null @@ -1,269 +0,0 @@ -package org.spongycastle.crypto.modes; - -import org.spongycastle.crypto.BlockCipher; -import org.spongycastle.crypto.BufferedBlockCipher; -import org.spongycastle.crypto.DataLengthException; -import org.spongycastle.crypto.InvalidCipherTextException; - -/** - * A Cipher Text Stealing (CTS) mode cipher. CTS allows block ciphers to - * be used to produce cipher text which is the same length as the plain text. - * <p> - * This version applies the CTS algorithm from one block up, rather than following the errata update issued in 2004, where CTS mode is applied - * from greater than 1 block up and the first block is processed using CBC mode. - * </p> - */ -public class OldCTSBlockCipher - extends BufferedBlockCipher -{ - private int blockSize; - - /** - * Create a buffered block cipher that uses Cipher Text Stealing - * - * @param cipher the underlying block cipher this buffering object wraps. - */ - public OldCTSBlockCipher( - BlockCipher cipher) - { - if ((cipher instanceof OFBBlockCipher) || (cipher instanceof CFBBlockCipher)) - { - throw new IllegalArgumentException("CTSBlockCipher can only accept ECB, or CBC ciphers"); - } - - this.cipher = cipher; - - blockSize = cipher.getBlockSize(); - - buf = new byte[blockSize * 2]; - bufOff = 0; - } - - /** - * 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 = total % buf.length; - - if (leftOver == 0) - { - return total - buf.length; - } - - return total - leftOver; - } - - /** - * return the size of the output buffer required for an update plus a - * doFinal with an input of len bytes. - * - * @param len the length of the input. - * @return the space required to accommodate a call to update and doFinal - * with len bytes of input. - */ - public int getOutputSize( - int len) - { - return len + bufOff; - } - - /** - * process a single byte, producing an output block if necessary. - * - * @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 org.spongycastle.crypto.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; - - if (bufOff == buf.length) - { - resultLen = cipher.processBlock(buf, 0, out, outOff); - System.arraycopy(buf, blockSize, buf, 0, blockSize); - - bufOff = blockSize; - } - - buf[bufOff++] = in; - - 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 org.spongycastle.crypto.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 DataLengthException("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); - System.arraycopy(buf, blockSize, buf, 0, blockSize); - - bufOff = blockSize; - - len -= gapLen; - inOff += gapLen; - - while (len > blockSize) - { - System.arraycopy(in, inOff, buf, bufOff, blockSize); - resultLen += cipher.processBlock(buf, 0, out, outOff + resultLen); - System.arraycopy(buf, blockSize, buf, 0, blockSize); - - len -= blockSize; - inOff += blockSize; - } - } - - System.arraycopy(in, inOff, buf, bufOff, len); - - bufOff += len; - - 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 org.spongycastle.crypto.DataLengthException if there is insufficient space in out for - * the output. - * @exception IllegalStateException if the underlying cipher is not - * initialised. - * @exception org.spongycastle.crypto.InvalidCipherTextException if cipher text decrypts wrongly (in - * case the exception will never get thrown). - */ - public int doFinal( - byte[] out, - int outOff) - throws DataLengthException, IllegalStateException, InvalidCipherTextException - { - if (bufOff + outOff > out.length) - { - throw new DataLengthException("output buffer to small in doFinal"); - } - - int blockSize = cipher.getBlockSize(); - int len = bufOff - blockSize; - byte[] block = new byte[blockSize]; - - if (forEncryption) - { - cipher.processBlock(buf, 0, block, 0); - - if (bufOff < blockSize) - { - throw new DataLengthException("need at least one block of input for CTS"); - } - - for (int i = bufOff; i != buf.length; i++) - { - buf[i] = block[i - blockSize]; - } - - for (int i = blockSize; i != bufOff; i++) - { - buf[i] ^= block[i - blockSize]; - } - - if (cipher instanceof CBCBlockCipher) - { - BlockCipher c = ((CBCBlockCipher)cipher).getUnderlyingCipher(); - - c.processBlock(buf, blockSize, out, outOff); - } - else - { - cipher.processBlock(buf, blockSize, out, outOff); - } - - System.arraycopy(block, 0, out, outOff + blockSize, len); - } - else - { - byte[] lastBlock = new byte[blockSize]; - - if (cipher instanceof CBCBlockCipher) - { - BlockCipher c = ((CBCBlockCipher)cipher).getUnderlyingCipher(); - - c.processBlock(buf, 0, block, 0); - } - else - { - cipher.processBlock(buf, 0, block, 0); - } - - for (int i = blockSize; i != bufOff; i++) - { - lastBlock[i - blockSize] = (byte)(block[i - blockSize] ^ buf[i]); - } - - System.arraycopy(buf, blockSize, block, 0, len); - - cipher.processBlock(block, 0, out, outOff); - System.arraycopy(lastBlock, 0, out, outOff + blockSize, len); - } - - int offset = bufOff; - - reset(); - - return offset; - } -} |