diff options
Diffstat (limited to 'bcprov/src/main/java/org/bouncycastle/crypto/engines/HC128Engine.java')
| -rw-r--r-- | bcprov/src/main/java/org/bouncycastle/crypto/engines/HC128Engine.java | 259 |
1 files changed, 0 insertions, 259 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/engines/HC128Engine.java b/bcprov/src/main/java/org/bouncycastle/crypto/engines/HC128Engine.java deleted file mode 100644 index 7d18d62..0000000 --- a/bcprov/src/main/java/org/bouncycastle/crypto/engines/HC128Engine.java +++ /dev/null @@ -1,259 +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; - -/** - * HC-128 is a software-efficient stream cipher created by Hongjun Wu. It - * generates keystream from a 128-bit secret key and a 128-bit initialization - * vector. - * <p> - * http://www.ecrypt.eu.org/stream/p3ciphers/hc/hc128_p3.pdf - * </p><p> - * It is a third phase candidate in the eStream contest, and is patent-free. - * No attacks are known as of today (April 2007). See - * - * http://www.ecrypt.eu.org/stream/hcp3.html - * </p> - */ -public class HC128Engine - implements StreamCipher -{ - private int[] p = new int[512]; - private int[] q = new int[512]; - private int cnt = 0; - - private static int f1(int x) - { - return rotateRight(x, 7) ^ rotateRight(x, 18) - ^ (x >>> 3); - } - - private static int f2(int x) - { - return rotateRight(x, 17) ^ rotateRight(x, 19) - ^ (x >>> 10); - } - - private int g1(int x, int y, int z) - { - return (rotateRight(x, 10) ^ rotateRight(z, 23)) - + rotateRight(y, 8); - } - - private int g2(int x, int y, int z) - { - return (rotateLeft(x, 10) ^ rotateLeft(z, 23)) + rotateLeft(y, 8); - } - - private static int rotateLeft( - int x, - int bits) - { - return (x << bits) | (x >>> -bits); - } - - private static int rotateRight( - int x, - int bits) - { - return (x >>> bits) | (x << -bits); - } - - private int h1(int x) - { - return q[x & 0xFF] + q[((x >> 16) & 0xFF) + 256]; - } - - private int h2(int x) - { - return p[x & 0xFF] + p[((x >> 16) & 0xFF) + 256]; - } - - private static int mod1024(int x) - { - return x & 0x3FF; - } - - private static int mod512(int x) - { - return x & 0x1FF; - } - - private static int dim(int x, int y) - { - return mod512(x - y); - } - - private int step() - { - int j = mod512(cnt); - int ret; - if (cnt < 512) - { - p[j] += g1(p[dim(j, 3)], p[dim(j, 10)], p[dim(j, 511)]); - ret = h1(p[dim(j, 12)]) ^ p[j]; - } - else - { - q[j] += g2(q[dim(j, 3)], q[dim(j, 10)], q[dim(j, 511)]); - ret = h2(q[dim(j, 12)]) ^ q[j]; - } - cnt = mod1024(cnt + 1); - return ret; - } - - private byte[] key, iv; - private boolean initialised; - - private void init() - { - if (key.length != 16) - { - throw new java.lang.IllegalArgumentException( - "The key must be 128 bits long"); - } - - idx = 0; - cnt = 0; - - int[] w = new int[1280]; - - for (int i = 0; i < 16; i++) - { - w[i >> 2] |= (key[i] & 0xff) << (8 * (i & 0x3)); - } - System.arraycopy(w, 0, w, 4, 4); - - for (int i = 0; i < iv.length && i < 16; i++) - { - w[(i >> 2) + 8] |= (iv[i] & 0xff) << (8 * (i & 0x3)); - } - System.arraycopy(w, 8, w, 12, 4); - - for (int i = 16; i < 1280; i++) - { - w[i] = f2(w[i - 2]) + w[i - 7] + f1(w[i - 15]) + w[i - 16] + i; - } - - System.arraycopy(w, 256, p, 0, 512); - System.arraycopy(w, 768, q, 0, 512); - - for (int i = 0; i < 512; i++) - { - p[i] = step(); - } - for (int i = 0; i < 512; i++) - { - q[i] = step(); - } - - cnt = 0; - } - - public String getAlgorithmName() - { - return "HC-128"; - } - - /** - * Initialise a HC-128 cipher. - * - * @param forEncryption whether or not we are for encryption. Irrelevant, as - * encryption and decryption are the same. - * @param params the parameters required to set up the cipher. - * @throws IllegalArgumentException if the params argument is - * inappropriate (ie. the key is not 128 bit long). - */ - public void init(boolean forEncryption, CipherParameters params) - throws IllegalArgumentException - { - CipherParameters keyParam = params; - - if (params instanceof ParametersWithIV) - { - iv = ((ParametersWithIV)params).getIV(); - keyParam = ((ParametersWithIV)params).getParameters(); - } - else - { - iv = new byte[0]; - } - - if (keyParam instanceof KeyParameter) - { - key = ((KeyParameter)keyParam).getKey(); - init(); - } - else - { - throw new IllegalArgumentException( - "Invalid parameter passed to HC128 init - " - + params.getClass().getName()); - } - - initialised = true; - } - - private byte[] buf = new byte[4]; - private int idx = 0; - - private byte getByte() - { - if (idx == 0) - { - int step = step(); - buf[0] = (byte)(step & 0xFF); - step >>= 8; - buf[1] = (byte)(step & 0xFF); - step >>= 8; - buf[2] = (byte)(step & 0xFF); - step >>= 8; - buf[3] = (byte)(step & 0xFF); - } - byte ret = buf[idx]; - idx = idx + 1 & 0x3; - return ret; - } - - 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] ^ getByte()); - } - - return len; - } - - public void reset() - { - init(); - } - - public byte returnByte(byte in) - { - return (byte)(in ^ getByte()); - } -} |