diff options
Diffstat (limited to 'bcprov/src/main/java/org/bouncycastle/crypto/engines/Grain128Engine.java')
-rw-r--r-- | bcprov/src/main/java/org/bouncycastle/crypto/engines/Grain128Engine.java | 304 |
1 files changed, 0 insertions, 304 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/engines/Grain128Engine.java b/bcprov/src/main/java/org/bouncycastle/crypto/engines/Grain128Engine.java deleted file mode 100644 index f5ecb75..0000000 --- a/bcprov/src/main/java/org/bouncycastle/crypto/engines/Grain128Engine.java +++ /dev/null @@ -1,304 +0,0 @@ -package org.bouncycastle.crypto.engines; - -import org.bouncycastle.crypto.CipherParameters; -import org.bouncycastle.crypto.DataLengthException; -import org.bouncycastle.crypto.OutputLengthException; -import org.bouncycastle.crypto.StreamCipher; -import org.bouncycastle.crypto.params.KeyParameter; -import org.bouncycastle.crypto.params.ParametersWithIV; - -/** - * Implementation of Martin Hell's, Thomas Johansson's and Willi Meier's stream - * cipher, Grain-128. - */ -public class Grain128Engine - implements StreamCipher -{ - - /** - * Constants - */ - private static final int STATE_SIZE = 4; - - /** - * Variables to hold the state of the engine during encryption and - * decryption - */ - private byte[] workingKey; - private byte[] workingIV; - private byte[] out; - private int[] lfsr; - private int[] nfsr; - private int output; - private int index = 4; - - private boolean initialised = false; - - public String getAlgorithmName() - { - return "Grain-128"; - } - - /** - * Initialize a Grain-128 cipher. - * - * @param forEncryption Whether or not we are for encryption. - * @param params The parameters required to set up the cipher. - * @throws IllegalArgumentException If the params argument is inappropriate. - */ - public void init(boolean forEncryption, CipherParameters params) - throws IllegalArgumentException - { - /** - * Grain encryption and decryption is completely symmetrical, so the - * 'forEncryption' is irrelevant. - */ - if (!(params instanceof ParametersWithIV)) - { - throw new IllegalArgumentException( - "Grain-128 Init parameters must include an IV"); - } - - ParametersWithIV ivParams = (ParametersWithIV)params; - - byte[] iv = ivParams.getIV(); - - if (iv == null || iv.length != 12) - { - throw new IllegalArgumentException( - "Grain-128 requires exactly 12 bytes of IV"); - } - - if (!(ivParams.getParameters() instanceof KeyParameter)) - { - throw new IllegalArgumentException( - "Grain-128 Init parameters must include a key"); - } - - KeyParameter key = (KeyParameter)ivParams.getParameters(); - - /** - * Initialize variables. - */ - workingIV = new byte[key.getKey().length]; - workingKey = new byte[key.getKey().length]; - lfsr = new int[STATE_SIZE]; - nfsr = new int[STATE_SIZE]; - out = new byte[4]; - - System.arraycopy(iv, 0, workingIV, 0, iv.length); - System.arraycopy(key.getKey(), 0, workingKey, 0, key.getKey().length); - - reset(); - } - - /** - * 256 clocks initialization phase. - */ - private void initGrain() - { - for (int i = 0; i < 8; i++) - { - output = getOutput(); - nfsr = shift(nfsr, getOutputNFSR() ^ lfsr[0] ^ output); - lfsr = shift(lfsr, getOutputLFSR() ^ output); - } - initialised = true; - } - - /** - * Get output from non-linear function g(x). - * - * @return Output from NFSR. - */ - private int getOutputNFSR() - { - int b0 = nfsr[0]; - int b3 = nfsr[0] >>> 3 | nfsr[1] << 29; - int b11 = nfsr[0] >>> 11 | nfsr[1] << 21; - int b13 = nfsr[0] >>> 13 | nfsr[1] << 19; - int b17 = nfsr[0] >>> 17 | nfsr[1] << 15; - int b18 = nfsr[0] >>> 18 | nfsr[1] << 14; - int b26 = nfsr[0] >>> 26 | nfsr[1] << 6; - int b27 = nfsr[0] >>> 27 | nfsr[1] << 5; - int b40 = nfsr[1] >>> 8 | nfsr[2] << 24; - int b48 = nfsr[1] >>> 16 | nfsr[2] << 16; - int b56 = nfsr[1] >>> 24 | nfsr[2] << 8; - int b59 = nfsr[1] >>> 27 | nfsr[2] << 5; - int b61 = nfsr[1] >>> 29 | nfsr[2] << 3; - int b65 = nfsr[2] >>> 1 | nfsr[3] << 31; - int b67 = nfsr[2] >>> 3 | nfsr[3] << 29; - int b68 = nfsr[2] >>> 4 | nfsr[3] << 28; - int b84 = nfsr[2] >>> 20 | nfsr[3] << 12; - int b91 = nfsr[2] >>> 27 | nfsr[3] << 5; - int b96 = nfsr[3]; - - return b0 ^ b26 ^ b56 ^ b91 ^ b96 ^ b3 & b67 ^ b11 & b13 ^ b17 & b18 - ^ b27 & b59 ^ b40 & b48 ^ b61 & b65 ^ b68 & b84; - } - - /** - * Get output from linear function f(x). - * - * @return Output from LFSR. - */ - private int getOutputLFSR() - { - int s0 = lfsr[0]; - int s7 = lfsr[0] >>> 7 | lfsr[1] << 25; - int s38 = lfsr[1] >>> 6 | lfsr[2] << 26; - int s70 = lfsr[2] >>> 6 | lfsr[3] << 26; - int s81 = lfsr[2] >>> 17 | lfsr[3] << 15; - int s96 = lfsr[3]; - - return s0 ^ s7 ^ s38 ^ s70 ^ s81 ^ s96; - } - - /** - * Get output from output function h(x). - * - * @return Output from h(x). - */ - private int getOutput() - { - int b2 = nfsr[0] >>> 2 | nfsr[1] << 30; - int b12 = nfsr[0] >>> 12 | nfsr[1] << 20; - int b15 = nfsr[0] >>> 15 | nfsr[1] << 17; - int b36 = nfsr[1] >>> 4 | nfsr[2] << 28; - int b45 = nfsr[1] >>> 13 | nfsr[2] << 19; - int b64 = nfsr[2]; - int b73 = nfsr[2] >>> 9 | nfsr[3] << 23; - int b89 = nfsr[2] >>> 25 | nfsr[3] << 7; - int b95 = nfsr[2] >>> 31 | nfsr[3] << 1; - int s8 = lfsr[0] >>> 8 | lfsr[1] << 24; - int s13 = lfsr[0] >>> 13 | lfsr[1] << 19; - int s20 = lfsr[0] >>> 20 | lfsr[1] << 12; - int s42 = lfsr[1] >>> 10 | lfsr[2] << 22; - int s60 = lfsr[1] >>> 28 | lfsr[2] << 4; - int s79 = lfsr[2] >>> 15 | lfsr[3] << 17; - int s93 = lfsr[2] >>> 29 | lfsr[3] << 3; - int s95 = lfsr[2] >>> 31 | lfsr[3] << 1; - - return b12 & s8 ^ s13 & s20 ^ b95 & s42 ^ s60 & s79 ^ b12 & b95 & s95 ^ s93 - ^ b2 ^ b15 ^ b36 ^ b45 ^ b64 ^ b73 ^ b89; - } - - /** - * Shift array 32 bits and add val to index.length - 1. - * - * @param array The array to shift. - * @param val The value to shift in. - * @return The shifted array with val added to index.length - 1. - */ - private int[] shift(int[] array, int val) - { - array[0] = array[1]; - array[1] = array[2]; - array[2] = array[3]; - array[3] = val; - - return array; - } - - /** - * Set keys, reset cipher. - * - * @param keyBytes The key. - * @param ivBytes The IV. - */ - private void setKey(byte[] keyBytes, byte[] ivBytes) - { - ivBytes[12] = (byte)0xFF; - ivBytes[13] = (byte)0xFF; - ivBytes[14] = (byte)0xFF; - ivBytes[15] = (byte)0xFF; - workingKey = keyBytes; - workingIV = ivBytes; - - /** - * Load NFSR and LFSR - */ - int j = 0; - for (int i = 0; i < nfsr.length; i++) - { - nfsr[i] = ((workingKey[j + 3]) << 24) | ((workingKey[j + 2]) << 16) - & 0x00FF0000 | ((workingKey[j + 1]) << 8) & 0x0000FF00 - | ((workingKey[j]) & 0x000000FF); - - lfsr[i] = ((workingIV[j + 3]) << 24) | ((workingIV[j + 2]) << 16) - & 0x00FF0000 | ((workingIV[j + 1]) << 8) & 0x0000FF00 - | ((workingIV[j]) & 0x000000FF); - j += 4; - } - } - - public int processBytes(byte[] in, int inOff, int len, byte[] out, - int outOff) - throws DataLengthException - { - if (!initialised) - { - throw new IllegalStateException(getAlgorithmName() - + " not initialised"); - } - - if ((inOff + len) > in.length) - { - throw new DataLengthException("input buffer too short"); - } - - if ((outOff + len) > out.length) - { - throw new OutputLengthException("output buffer too short"); - } - - for (int i = 0; i < len; i++) - { - out[outOff + i] = (byte)(in[inOff + i] ^ getKeyStream()); - } - - return len; - } - - public void reset() - { - index = 4; - setKey(workingKey, workingIV); - initGrain(); - } - - /** - * Run Grain one round(i.e. 32 bits). - */ - private void oneRound() - { - output = getOutput(); - out[0] = (byte)output; - out[1] = (byte)(output >> 8); - out[2] = (byte)(output >> 16); - out[3] = (byte)(output >> 24); - - nfsr = shift(nfsr, getOutputNFSR() ^ lfsr[0]); - lfsr = shift(lfsr, getOutputLFSR()); - } - - public byte returnByte(byte in) - { - if (!initialised) - { - throw new IllegalStateException(getAlgorithmName() - + " not initialised"); - } - return (byte)(in ^ getKeyStream()); - } - - private byte getKeyStream() - { - if (index > 3) - { - oneRound(); - index = 0; - } - return out[index++]; - } -} |