diff options
Diffstat (limited to 'libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/PGPCFBBlockCipher.java')
-rw-r--r-- | libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/PGPCFBBlockCipher.java | 455 |
1 files changed, 0 insertions, 455 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/PGPCFBBlockCipher.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/PGPCFBBlockCipher.java deleted file mode 100644 index 370ce40d9..000000000 --- a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/modes/PGPCFBBlockCipher.java +++ /dev/null @@ -1,455 +0,0 @@ -package org.spongycastle.crypto.modes; - -import org.spongycastle.crypto.BlockCipher; -import org.spongycastle.crypto.CipherParameters; -import org.spongycastle.crypto.DataLengthException; -import org.spongycastle.crypto.params.ParametersWithIV; - -/** - * Implements OpenPGP's rather strange version of Cipher-FeedBack (CFB) mode on top of a simple cipher. For further info see <a href="http://www.ietf.org/rfc/rfc2440.html">RFC 2440</a>. - */ -public class PGPCFBBlockCipher - implements BlockCipher -{ - private byte[] IV; - private byte[] FR; - private byte[] FRE; - private byte[] tmp; - - private BlockCipher cipher; - - private int count; - private int blockSize; - private boolean forEncryption; - - private boolean inlineIv; // if false we don't need to prepend an IV - - /** - * Basic constructor. - * - * @param cipher the block cipher to be used as the basis of the - * feedback mode. - * @param inlineIv if true this is for PGP CFB with a prepended iv. - */ - public PGPCFBBlockCipher( - BlockCipher cipher, - boolean inlineIv) - { - this.cipher = cipher; - this.inlineIv = inlineIv; - - this.blockSize = cipher.getBlockSize(); - this.IV = new byte[blockSize]; - this.FR = new byte[blockSize]; - this.FRE = new byte[blockSize]; - this.tmp = new byte[blockSize]; - } - - /** - * return the underlying block cipher that we are wrapping. - * - * @return the underlying block cipher that we are wrapping. - */ - public BlockCipher getUnderlyingCipher() - { - return cipher; - } - - /** - * return the algorithm name and mode. - * - * @return the name of the underlying algorithm followed by "/PGPCFB" - * and the block size in bits. - */ - public String getAlgorithmName() - { - if (inlineIv) - { - return cipher.getAlgorithmName() + "/PGPCFBwithIV"; - } - else - { - return cipher.getAlgorithmName() + "/PGPCFB"; - } - } - - /** - * return the block size we are operating at. - * - * @return the block size we are operating at (in bytes). - */ - public int getBlockSize() - { - return cipher.getBlockSize(); - } - - /** - * 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 (inlineIv) - { - return (forEncryption) ? encryptBlockWithIV(in, inOff, out, outOff) : decryptBlockWithIV(in, inOff, out, outOff); - } - else - { - return (forEncryption) ? encryptBlock(in, inOff, out, outOff) : decryptBlock(in, inOff, out, outOff); - } - } - - /** - * reset the chaining vector back to the IV and reset the underlying - * cipher. - */ - public void reset() - { - count = 0; - - for (int i = 0; i != FR.length; i++) - { - if (inlineIv) - { - FR[i] = 0; - } - else - { - FR[i] = IV[i]; // if simple mode, key is IV (even if this is zero) - } - } - - cipher.reset(); - } - - /** - * 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 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; - - if (params instanceof ParametersWithIV) - { - ParametersWithIV ivParam = (ParametersWithIV)params; - byte[] iv = ivParam.getIV(); - - if (iv.length < IV.length) - { - // prepend the supplied IV with zeros (per FIPS PUB 81) - System.arraycopy(iv, 0, IV, IV.length - iv.length, iv.length); - for (int i = 0; i < IV.length - iv.length; i++) - { - IV[i] = 0; - } - } - else - { - System.arraycopy(iv, 0, IV, 0, IV.length); - } - - reset(); - - cipher.init(true, ivParam.getParameters()); - } - else - { - reset(); - - cipher.init(true, params); - } - } - - /** - * Encrypt one byte of data according to CFB mode. - * @param data the byte to encrypt - * @param blockOff where am i in the current block, determines when to resync the block - * @returns the encrypted byte - */ - private byte encryptByte(byte data, int blockOff) - { - return (byte)(FRE[blockOff] ^ data); - } - - /** - * Do the appropriate processing for CFB IV mode encryption. - * - * @param in the array containing the data to be encrypted. - * @param inOff offset into the in array the data starts at. - * @param out the array the encrypted 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. - */ - private int encryptBlockWithIV( - byte[] in, - int inOff, - byte[] out, - int outOff) - throws DataLengthException, IllegalStateException - { - if ((inOff + blockSize) > in.length) - { - throw new DataLengthException("input buffer too short"); - } - - if (count == 0) - { - if ((outOff + 2 * blockSize + 2) > out.length) - { - throw new DataLengthException("output buffer too short"); - } - - cipher.processBlock(FR, 0, FRE, 0); - - for (int n = 0; n < blockSize; n++) - { - out[outOff + n] = encryptByte(IV[n], n); - } - - System.arraycopy(out, outOff, FR, 0, blockSize); - - cipher.processBlock(FR, 0, FRE, 0); - - out[outOff + blockSize] = encryptByte(IV[blockSize - 2], 0); - out[outOff + blockSize + 1] = encryptByte(IV[blockSize - 1], 1); - - System.arraycopy(out, outOff + 2, FR, 0, blockSize); - - cipher.processBlock(FR, 0, FRE, 0); - - for (int n = 0; n < blockSize; n++) - { - out[outOff + blockSize + 2 + n] = encryptByte(in[inOff + n], n); - } - - System.arraycopy(out, outOff + blockSize + 2, FR, 0, blockSize); - - count += 2 * blockSize + 2; - - return 2 * blockSize + 2; - } - else if (count >= blockSize + 2) - { - if ((outOff + blockSize) > out.length) - { - throw new DataLengthException("output buffer too short"); - } - - cipher.processBlock(FR, 0, FRE, 0); - - for (int n = 0; n < blockSize; n++) - { - out[outOff + n] = encryptByte(in[inOff + n], n); - } - - System.arraycopy(out, outOff, FR, 0, blockSize); - } - - return blockSize; - } - - /** - * Do the appropriate processing for CFB IV mode decryption. - * - * @param in the array containing the data to be decrypted. - * @param inOff offset into the in array the data starts at. - * @param out the array the encrypted 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. - */ - private int decryptBlockWithIV( - 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"); - } - - if (count == 0) - { - for (int n = 0; n < blockSize; n++) - { - FR[n] = in[inOff + n]; - } - - cipher.processBlock(FR, 0, FRE, 0); - - count += blockSize; - - return 0; - } - else if (count == blockSize) - { - // copy in buffer so that this mode works if in and out are the same - System.arraycopy(in, inOff, tmp, 0, blockSize); - - System.arraycopy(FR, 2, FR, 0, blockSize - 2); - - FR[blockSize - 2] = tmp[0]; - FR[blockSize - 1] = tmp[1]; - - cipher.processBlock(FR, 0, FRE, 0); - - for (int n = 0; n < blockSize - 2; n++) - { - out[outOff + n] = encryptByte(tmp[n + 2], n); - } - - System.arraycopy(tmp, 2, FR, 0, blockSize - 2); - - count += 2; - - return blockSize - 2; - } - else if (count >= blockSize + 2) - { - // copy in buffer so that this mode works if in and out are the same - System.arraycopy(in, inOff, tmp, 0, blockSize); - - out[outOff + 0] = encryptByte(tmp[0], blockSize - 2); - out[outOff + 1] = encryptByte(tmp[1], blockSize - 1); - - System.arraycopy(tmp, 0, FR, blockSize - 2, 2); - - cipher.processBlock(FR, 0, FRE, 0); - - for (int n = 0; n < blockSize - 2; n++) - { - out[outOff + n + 2] = encryptByte(tmp[n + 2], n); - } - - System.arraycopy(tmp, 2, FR, 0, blockSize - 2); - - } - - return blockSize; - } - - /** - * Do the appropriate processing for CFB mode encryption. - * - * @param in the array containing the data to be encrypted. - * @param inOff offset into the in array the data starts at. - * @param out the array the encrypted 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. - */ - private int encryptBlock( - 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(FR, 0, FRE, 0); - for (int n = 0; n < blockSize; n++) - { - out[outOff + n] = encryptByte(in[inOff + n], n); - } - - for (int n = 0; n < blockSize; n++) - { - FR[n] = out[outOff + n]; - } - - return blockSize; - - } - - /** - * Do the appropriate processing for CFB mode decryption. - * - * @param in the array containing the data to be decrypted. - * @param inOff offset into the in array the data starts at. - * @param out the array the encrypted 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. - */ - private int decryptBlock( - 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(FR, 0, FRE, 0); - for (int n = 0; n < blockSize; n++) - { - out[outOff + n] = encryptByte(in[inOff + n], n); - } - - for (int n = 0; n < blockSize; n++) - { - FR[n] = in[inOff + n]; - } - - return blockSize; - - } -} |