diff options
Diffstat (limited to 'bcprov/src/main/java/org/bouncycastle/crypto/macs/CFBBlockCipherMac.java')
| -rw-r--r-- | bcprov/src/main/java/org/bouncycastle/crypto/macs/CFBBlockCipherMac.java | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/macs/CFBBlockCipherMac.java b/bcprov/src/main/java/org/bouncycastle/crypto/macs/CFBBlockCipherMac.java deleted file mode 100644 index d7ad612..0000000 --- a/bcprov/src/main/java/org/bouncycastle/crypto/macs/CFBBlockCipherMac.java +++ /dev/null @@ -1,388 +0,0 @@ -package org.bouncycastle.crypto.macs; - -import org.bouncycastle.crypto.BlockCipher; -import org.bouncycastle.crypto.CipherParameters; -import org.bouncycastle.crypto.DataLengthException; -import org.bouncycastle.crypto.Mac; -import org.bouncycastle.crypto.paddings.BlockCipherPadding; -import org.bouncycastle.crypto.params.ParametersWithIV; - -/** - * implements a Cipher-FeedBack (CFB) mode on top of a simple cipher. - */ -class MacCFBBlockCipher -{ - private byte[] IV; - private byte[] cfbV; - private byte[] cfbOutV; - - private int blockSize; - private BlockCipher cipher = null; - - /** - * Basic constructor. - * - * @param cipher the block cipher to be used as the basis of the - * feedback mode. - * @param blockSize the block size in bits (note: a multiple of 8) - */ - public MacCFBBlockCipher( - BlockCipher cipher, - int bitBlockSize) - { - this.cipher = cipher; - this.blockSize = bitBlockSize / 8; - - this.IV = new byte[cipher.getBlockSize()]; - this.cfbV = new byte[cipher.getBlockSize()]; - this.cfbOutV = new byte[cipher.getBlockSize()]; - } - - /** - * Initialise the cipher and, possibly, the initialisation vector (IV). - * If an IV isn't passed as part of the parameter, the IV will be all zeros. - * An IV which is too short is handled in FIPS compliant fashion. - * - * @param param the key and other data required by the cipher. - * @exception IllegalArgumentException if the params argument is - * inappropriate. - */ - public void init( - CipherParameters params) - throws IllegalArgumentException - { - if (params instanceof ParametersWithIV) - { - ParametersWithIV ivParam = (ParametersWithIV)params; - byte[] iv = ivParam.getIV(); - - if (iv.length < IV.length) - { - System.arraycopy(iv, 0, IV, IV.length - iv.length, iv.length); - } - else - { - System.arraycopy(iv, 0, IV, 0, IV.length); - } - - reset(); - - cipher.init(true, ivParam.getParameters()); - } - else - { - reset(); - - cipher.init(true, params); - } - } - - /** - * return the algorithm name and mode. - * - * @return the name of the underlying algorithm followed by "/CFB" - * and the block size in bits. - */ - public String getAlgorithmName() - { - return cipher.getAlgorithmName() + "/CFB" + (blockSize * 8); - } - - /** - * return the block size we are operating at. - * - * @return the block size we are operating at (in bytes). - */ - public int getBlockSize() - { - return blockSize; - } - - /** - * Process one block of input from the array in and write it to - * the out array. - * - * @param in the array containing the input data. - * @param inOff offset into the in array the data starts at. - * @param out the array the output data will be copied into. - * @param outOff the offset into the out array the output will start at. - * @exception DataLengthException if there isn't enough data in in, or - * space in out. - * @exception IllegalStateException if the cipher isn't initialised. - * @return the number of bytes processed and produced. - */ - public int processBlock( - byte[] in, - int inOff, - byte[] out, - int outOff) - throws DataLengthException, IllegalStateException - { - if ((inOff + blockSize) > in.length) - { - throw new DataLengthException("input buffer too short"); - } - - if ((outOff + blockSize) > out.length) - { - throw new DataLengthException("output buffer too short"); - } - - cipher.processBlock(cfbV, 0, cfbOutV, 0); - - // - // XOR the cfbV with the plaintext producing the cipher text - // - for (int i = 0; i < blockSize; i++) - { - out[outOff + i] = (byte)(cfbOutV[i] ^ in[inOff + i]); - } - - // - // change over the input block. - // - System.arraycopy(cfbV, blockSize, cfbV, 0, cfbV.length - blockSize); - System.arraycopy(out, outOff, cfbV, cfbV.length - blockSize, blockSize); - - return blockSize; - } - - /** - * reset the chaining vector back to the IV and reset the underlying - * cipher. - */ - public void reset() - { - System.arraycopy(IV, 0, cfbV, 0, IV.length); - - cipher.reset(); - } - - void getMacBlock( - byte[] mac) - { - cipher.processBlock(cfbV, 0, mac, 0); - } -} - -public class CFBBlockCipherMac - implements Mac -{ - private byte[] mac; - - private byte[] buf; - private int bufOff; - private MacCFBBlockCipher cipher; - private BlockCipherPadding padding = null; - - - private int macSize; - - /** - * create a standard MAC based on a CFB block cipher. This will produce an - * authentication code half the length of the block size of the cipher, with - * the CFB mode set to 8 bits. - * - * @param cipher the cipher to be used as the basis of the MAC generation. - */ - public CFBBlockCipherMac( - BlockCipher cipher) - { - this(cipher, 8, (cipher.getBlockSize() * 8) / 2, null); - } - - /** - * create a standard MAC based on a CFB block cipher. This will produce an - * authentication code half the length of the block size of the cipher, with - * the CFB mode set to 8 bits. - * - * @param cipher the cipher to be used as the basis of the MAC generation. - * @param padding the padding to be used. - */ - public CFBBlockCipherMac( - BlockCipher cipher, - BlockCipherPadding padding) - { - this(cipher, 8, (cipher.getBlockSize() * 8) / 2, padding); - } - - /** - * create a standard MAC based on a block cipher with the size of the - * MAC been given in bits. This class uses CFB mode as the basis for the - * MAC generation. - * <p> - * Note: the size of the MAC must be at least 24 bits (FIPS Publication 81), - * or 16 bits if being used as a data authenticator (FIPS Publication 113), - * and in general should be less than the size of the block cipher as it reduces - * the chance of an exhaustive attack (see Handbook of Applied Cryptography). - * - * @param cipher the cipher to be used as the basis of the MAC generation. - * @param cfbBitSize the size of an output block produced by the CFB mode. - * @param macSizeInBits the size of the MAC in bits, must be a multiple of 8. - */ - public CFBBlockCipherMac( - BlockCipher cipher, - int cfbBitSize, - int macSizeInBits) - { - this(cipher, cfbBitSize, macSizeInBits, null); - } - - /** - * create a standard MAC based on a block cipher with the size of the - * MAC been given in bits. This class uses CFB mode as the basis for the - * MAC generation. - * <p> - * Note: the size of the MAC must be at least 24 bits (FIPS Publication 81), - * or 16 bits if being used as a data authenticator (FIPS Publication 113), - * and in general should be less than the size of the block cipher as it reduces - * the chance of an exhaustive attack (see Handbook of Applied Cryptography). - * - * @param cipher the cipher to be used as the basis of the MAC generation. - * @param cfbBitSize the size of an output block produced by the CFB mode. - * @param macSizeInBits the size of the MAC in bits, must be a multiple of 8. - * @param padding a padding to be used. - */ - public CFBBlockCipherMac( - BlockCipher cipher, - int cfbBitSize, - int macSizeInBits, - BlockCipherPadding padding) - { - if ((macSizeInBits % 8) != 0) - { - throw new IllegalArgumentException("MAC size must be multiple of 8"); - } - - mac = new byte[cipher.getBlockSize()]; - - this.cipher = new MacCFBBlockCipher(cipher, cfbBitSize); - this.padding = padding; - this.macSize = macSizeInBits / 8; - - buf = new byte[this.cipher.getBlockSize()]; - bufOff = 0; - } - - public String getAlgorithmName() - { - return cipher.getAlgorithmName(); - } - - public void init( - CipherParameters params) - { - reset(); - - cipher.init(params); - } - - public int getMacSize() - { - return macSize; - } - - public void update( - byte in) - { - if (bufOff == buf.length) - { - cipher.processBlock(buf, 0, mac, 0); - bufOff = 0; - } - - buf[bufOff++] = in; - } - - public void update( - byte[] in, - int inOff, - int len) - { - if (len < 0) - { - throw new IllegalArgumentException("Can't have a negative input length!"); - } - - int blockSize = cipher.getBlockSize(); - int resultLen = 0; - int gapLen = blockSize - bufOff; - - if (len > gapLen) - { - System.arraycopy(in, inOff, buf, bufOff, gapLen); - - resultLen += cipher.processBlock(buf, 0, mac, 0); - - bufOff = 0; - len -= gapLen; - inOff += gapLen; - - while (len > blockSize) - { - resultLen += cipher.processBlock(in, inOff, mac, 0); - - len -= blockSize; - inOff += blockSize; - } - } - - System.arraycopy(in, inOff, buf, bufOff, len); - - bufOff += len; - } - - public int doFinal( - byte[] out, - int outOff) - { - int blockSize = cipher.getBlockSize(); - - // - // pad with zeroes - // - if (this.padding == null) - { - while (bufOff < blockSize) - { - buf[bufOff] = 0; - bufOff++; - } - } - else - { - padding.addPadding(buf, bufOff); - } - - cipher.processBlock(buf, 0, mac, 0); - - cipher.getMacBlock(mac); - - System.arraycopy(mac, 0, out, outOff, macSize); - - reset(); - - return macSize; - } - - /** - * Reset the mac generator. - */ - 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(); - } -} |