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-rw-r--r--libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/RC2Engine.java317
1 files changed, 317 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/RC2Engine.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/RC2Engine.java
new file mode 100644
index 000000000..24bdab6a7
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/RC2Engine.java
@@ -0,0 +1,317 @@
+package org.spongycastle.crypto.engines;
+
+import org.spongycastle.crypto.BlockCipher;
+import org.spongycastle.crypto.CipherParameters;
+import org.spongycastle.crypto.DataLengthException;
+import org.spongycastle.crypto.OutputLengthException;
+import org.spongycastle.crypto.params.KeyParameter;
+import org.spongycastle.crypto.params.RC2Parameters;
+
+/**
+ * an implementation of RC2 as described in RFC 2268
+ * "A Description of the RC2(r) Encryption Algorithm" R. Rivest.
+ */
+public class RC2Engine
+ implements BlockCipher
+{
+ //
+ // the values we use for key expansion (based on the digits of PI)
+ //
+ private static byte[] piTable =
+ {
+ (byte)0xd9, (byte)0x78, (byte)0xf9, (byte)0xc4, (byte)0x19, (byte)0xdd, (byte)0xb5, (byte)0xed,
+ (byte)0x28, (byte)0xe9, (byte)0xfd, (byte)0x79, (byte)0x4a, (byte)0xa0, (byte)0xd8, (byte)0x9d,
+ (byte)0xc6, (byte)0x7e, (byte)0x37, (byte)0x83, (byte)0x2b, (byte)0x76, (byte)0x53, (byte)0x8e,
+ (byte)0x62, (byte)0x4c, (byte)0x64, (byte)0x88, (byte)0x44, (byte)0x8b, (byte)0xfb, (byte)0xa2,
+ (byte)0x17, (byte)0x9a, (byte)0x59, (byte)0xf5, (byte)0x87, (byte)0xb3, (byte)0x4f, (byte)0x13,
+ (byte)0x61, (byte)0x45, (byte)0x6d, (byte)0x8d, (byte)0x9, (byte)0x81, (byte)0x7d, (byte)0x32,
+ (byte)0xbd, (byte)0x8f, (byte)0x40, (byte)0xeb, (byte)0x86, (byte)0xb7, (byte)0x7b, (byte)0xb,
+ (byte)0xf0, (byte)0x95, (byte)0x21, (byte)0x22, (byte)0x5c, (byte)0x6b, (byte)0x4e, (byte)0x82,
+ (byte)0x54, (byte)0xd6, (byte)0x65, (byte)0x93, (byte)0xce, (byte)0x60, (byte)0xb2, (byte)0x1c,
+ (byte)0x73, (byte)0x56, (byte)0xc0, (byte)0x14, (byte)0xa7, (byte)0x8c, (byte)0xf1, (byte)0xdc,
+ (byte)0x12, (byte)0x75, (byte)0xca, (byte)0x1f, (byte)0x3b, (byte)0xbe, (byte)0xe4, (byte)0xd1,
+ (byte)0x42, (byte)0x3d, (byte)0xd4, (byte)0x30, (byte)0xa3, (byte)0x3c, (byte)0xb6, (byte)0x26,
+ (byte)0x6f, (byte)0xbf, (byte)0xe, (byte)0xda, (byte)0x46, (byte)0x69, (byte)0x7, (byte)0x57,
+ (byte)0x27, (byte)0xf2, (byte)0x1d, (byte)0x9b, (byte)0xbc, (byte)0x94, (byte)0x43, (byte)0x3,
+ (byte)0xf8, (byte)0x11, (byte)0xc7, (byte)0xf6, (byte)0x90, (byte)0xef, (byte)0x3e, (byte)0xe7,
+ (byte)0x6, (byte)0xc3, (byte)0xd5, (byte)0x2f, (byte)0xc8, (byte)0x66, (byte)0x1e, (byte)0xd7,
+ (byte)0x8, (byte)0xe8, (byte)0xea, (byte)0xde, (byte)0x80, (byte)0x52, (byte)0xee, (byte)0xf7,
+ (byte)0x84, (byte)0xaa, (byte)0x72, (byte)0xac, (byte)0x35, (byte)0x4d, (byte)0x6a, (byte)0x2a,
+ (byte)0x96, (byte)0x1a, (byte)0xd2, (byte)0x71, (byte)0x5a, (byte)0x15, (byte)0x49, (byte)0x74,
+ (byte)0x4b, (byte)0x9f, (byte)0xd0, (byte)0x5e, (byte)0x4, (byte)0x18, (byte)0xa4, (byte)0xec,
+ (byte)0xc2, (byte)0xe0, (byte)0x41, (byte)0x6e, (byte)0xf, (byte)0x51, (byte)0xcb, (byte)0xcc,
+ (byte)0x24, (byte)0x91, (byte)0xaf, (byte)0x50, (byte)0xa1, (byte)0xf4, (byte)0x70, (byte)0x39,
+ (byte)0x99, (byte)0x7c, (byte)0x3a, (byte)0x85, (byte)0x23, (byte)0xb8, (byte)0xb4, (byte)0x7a,
+ (byte)0xfc, (byte)0x2, (byte)0x36, (byte)0x5b, (byte)0x25, (byte)0x55, (byte)0x97, (byte)0x31,
+ (byte)0x2d, (byte)0x5d, (byte)0xfa, (byte)0x98, (byte)0xe3, (byte)0x8a, (byte)0x92, (byte)0xae,
+ (byte)0x5, (byte)0xdf, (byte)0x29, (byte)0x10, (byte)0x67, (byte)0x6c, (byte)0xba, (byte)0xc9,
+ (byte)0xd3, (byte)0x0, (byte)0xe6, (byte)0xcf, (byte)0xe1, (byte)0x9e, (byte)0xa8, (byte)0x2c,
+ (byte)0x63, (byte)0x16, (byte)0x1, (byte)0x3f, (byte)0x58, (byte)0xe2, (byte)0x89, (byte)0xa9,
+ (byte)0xd, (byte)0x38, (byte)0x34, (byte)0x1b, (byte)0xab, (byte)0x33, (byte)0xff, (byte)0xb0,
+ (byte)0xbb, (byte)0x48, (byte)0xc, (byte)0x5f, (byte)0xb9, (byte)0xb1, (byte)0xcd, (byte)0x2e,
+ (byte)0xc5, (byte)0xf3, (byte)0xdb, (byte)0x47, (byte)0xe5, (byte)0xa5, (byte)0x9c, (byte)0x77,
+ (byte)0xa, (byte)0xa6, (byte)0x20, (byte)0x68, (byte)0xfe, (byte)0x7f, (byte)0xc1, (byte)0xad
+ };
+
+ private static final int BLOCK_SIZE = 8;
+
+ private int[] workingKey;
+ private boolean encrypting;
+
+ private int[] generateWorkingKey(
+ byte[] key,
+ int bits)
+ {
+ int x;
+ int[] xKey = new int[128];
+
+ for (int i = 0; i != key.length; i++)
+ {
+ xKey[i] = key[i] & 0xff;
+ }
+
+ // Phase 1: Expand input key to 128 bytes
+ int len = key.length;
+
+ if (len < 128)
+ {
+ int index = 0;
+
+ x = xKey[len - 1];
+
+ do
+ {
+ x = piTable[(x + xKey[index++]) & 255] & 0xff;
+ xKey[len++] = x;
+ }
+ while (len < 128);
+ }
+
+ // Phase 2 - reduce effective key size to "bits"
+ len = (bits + 7) >> 3;
+ x = piTable[xKey[128 - len] & (255 >> (7 & -bits))] & 0xff;
+ xKey[128 - len] = x;
+
+ for (int i = 128 - len - 1; i >= 0; i--)
+ {
+ x = piTable[x ^ xKey[i + len]] & 0xff;
+ xKey[i] = x;
+ }
+
+ // Phase 3 - copy to newKey in little-endian order
+ int[] newKey = new int[64];
+
+ for (int i = 0; i != newKey.length; i++)
+ {
+ newKey[i] = (xKey[2 * i] + (xKey[2 * i + 1] << 8));
+ }
+
+ return newKey;
+ }
+
+ /**
+ * initialise a RC2 cipher.
+ *
+ * @param encrypting whether or not we are for encryption.
+ * @param params the parameters required to set up the cipher.
+ * @exception IllegalArgumentException if the params argument is
+ * inappropriate.
+ */
+ public void init(
+ boolean encrypting,
+ CipherParameters params)
+ {
+ this.encrypting = encrypting;
+
+ if (params instanceof RC2Parameters)
+ {
+ RC2Parameters param = (RC2Parameters)params;
+
+ workingKey = generateWorkingKey(param.getKey(),
+ param.getEffectiveKeyBits());
+ }
+ else if (params instanceof KeyParameter)
+ {
+ byte[] key = ((KeyParameter)params).getKey();
+
+ workingKey = generateWorkingKey(key, key.length * 8);
+ }
+ else
+ {
+ throw new IllegalArgumentException("invalid parameter passed to RC2 init - " + params.getClass().getName());
+ }
+
+ }
+
+ public void reset()
+ {
+ }
+
+ public String getAlgorithmName()
+ {
+ return "RC2";
+ }
+
+ public int getBlockSize()
+ {
+ return BLOCK_SIZE;
+ }
+
+ public final int processBlock(
+ byte[] in,
+ int inOff,
+ byte[] out,
+ int outOff)
+ {
+ if (workingKey == null)
+ {
+ throw new IllegalStateException("RC2 engine not initialised");
+ }
+
+ if ((inOff + BLOCK_SIZE) > in.length)
+ {
+ throw new DataLengthException("input buffer too short");
+ }
+
+ if ((outOff + BLOCK_SIZE) > out.length)
+ {
+ throw new OutputLengthException("output buffer too short");
+ }
+
+ if (encrypting)
+ {
+ encryptBlock(in, inOff, out, outOff);
+ }
+ else
+ {
+ decryptBlock(in, inOff, out, outOff);
+ }
+
+ return BLOCK_SIZE;
+ }
+
+ /**
+ * return the result rotating the 16 bit number in x left by y
+ */
+ private int rotateWordLeft(
+ int x,
+ int y)
+ {
+ x &= 0xffff;
+ return (x << y) | (x >> (16 - y));
+ }
+
+ private void encryptBlock(
+ byte[] in,
+ int inOff,
+ byte[] out,
+ int outOff)
+ {
+ int x76, x54, x32, x10;
+
+ x76 = ((in[inOff + 7] & 0xff) << 8) + (in[inOff + 6] & 0xff);
+ x54 = ((in[inOff + 5] & 0xff) << 8) + (in[inOff + 4] & 0xff);
+ x32 = ((in[inOff + 3] & 0xff) << 8) + (in[inOff + 2] & 0xff);
+ x10 = ((in[inOff + 1] & 0xff) << 8) + (in[inOff + 0] & 0xff);
+
+ for (int i = 0; i <= 16; i += 4)
+ {
+ x10 = rotateWordLeft(x10 + (x32 & ~x76) + (x54 & x76) + workingKey[i ], 1);
+ x32 = rotateWordLeft(x32 + (x54 & ~x10) + (x76 & x10) + workingKey[i+1], 2);
+ x54 = rotateWordLeft(x54 + (x76 & ~x32) + (x10 & x32) + workingKey[i+2], 3);
+ x76 = rotateWordLeft(x76 + (x10 & ~x54) + (x32 & x54) + workingKey[i+3], 5);
+ }
+
+ x10 += workingKey[x76 & 63];
+ x32 += workingKey[x10 & 63];
+ x54 += workingKey[x32 & 63];
+ x76 += workingKey[x54 & 63];
+
+ for (int i = 20; i <= 40; i += 4)
+ {
+ x10 = rotateWordLeft(x10 + (x32 & ~x76) + (x54 & x76) + workingKey[i ], 1);
+ x32 = rotateWordLeft(x32 + (x54 & ~x10) + (x76 & x10) + workingKey[i+1], 2);
+ x54 = rotateWordLeft(x54 + (x76 & ~x32) + (x10 & x32) + workingKey[i+2], 3);
+ x76 = rotateWordLeft(x76 + (x10 & ~x54) + (x32 & x54) + workingKey[i+3], 5);
+ }
+
+ x10 += workingKey[x76 & 63];
+ x32 += workingKey[x10 & 63];
+ x54 += workingKey[x32 & 63];
+ x76 += workingKey[x54 & 63];
+
+ for (int i = 44; i < 64; i += 4)
+ {
+ x10 = rotateWordLeft(x10 + (x32 & ~x76) + (x54 & x76) + workingKey[i ], 1);
+ x32 = rotateWordLeft(x32 + (x54 & ~x10) + (x76 & x10) + workingKey[i+1], 2);
+ x54 = rotateWordLeft(x54 + (x76 & ~x32) + (x10 & x32) + workingKey[i+2], 3);
+ x76 = rotateWordLeft(x76 + (x10 & ~x54) + (x32 & x54) + workingKey[i+3], 5);
+ }
+
+ out[outOff + 0] = (byte)x10;
+ out[outOff + 1] = (byte)(x10 >> 8);
+ out[outOff + 2] = (byte)x32;
+ out[outOff + 3] = (byte)(x32 >> 8);
+ out[outOff + 4] = (byte)x54;
+ out[outOff + 5] = (byte)(x54 >> 8);
+ out[outOff + 6] = (byte)x76;
+ out[outOff + 7] = (byte)(x76 >> 8);
+ }
+
+ private void decryptBlock(
+ byte[] in,
+ int inOff,
+ byte[] out,
+ int outOff)
+ {
+ int x76, x54, x32, x10;
+
+ x76 = ((in[inOff + 7] & 0xff) << 8) + (in[inOff + 6] & 0xff);
+ x54 = ((in[inOff + 5] & 0xff) << 8) + (in[inOff + 4] & 0xff);
+ x32 = ((in[inOff + 3] & 0xff) << 8) + (in[inOff + 2] & 0xff);
+ x10 = ((in[inOff + 1] & 0xff) << 8) + (in[inOff + 0] & 0xff);
+
+ for (int i = 60; i >= 44; i -= 4)
+ {
+ x76 = rotateWordLeft(x76, 11) - ((x10 & ~x54) + (x32 & x54) + workingKey[i+3]);
+ x54 = rotateWordLeft(x54, 13) - ((x76 & ~x32) + (x10 & x32) + workingKey[i+2]);
+ x32 = rotateWordLeft(x32, 14) - ((x54 & ~x10) + (x76 & x10) + workingKey[i+1]);
+ x10 = rotateWordLeft(x10, 15) - ((x32 & ~x76) + (x54 & x76) + workingKey[i ]);
+ }
+
+ x76 -= workingKey[x54 & 63];
+ x54 -= workingKey[x32 & 63];
+ x32 -= workingKey[x10 & 63];
+ x10 -= workingKey[x76 & 63];
+
+ for (int i = 40; i >= 20; i -= 4)
+ {
+ x76 = rotateWordLeft(x76, 11) - ((x10 & ~x54) + (x32 & x54) + workingKey[i+3]);
+ x54 = rotateWordLeft(x54, 13) - ((x76 & ~x32) + (x10 & x32) + workingKey[i+2]);
+ x32 = rotateWordLeft(x32, 14) - ((x54 & ~x10) + (x76 & x10) + workingKey[i+1]);
+ x10 = rotateWordLeft(x10, 15) - ((x32 & ~x76) + (x54 & x76) + workingKey[i ]);
+ }
+
+ x76 -= workingKey[x54 & 63];
+ x54 -= workingKey[x32 & 63];
+ x32 -= workingKey[x10 & 63];
+ x10 -= workingKey[x76 & 63];
+
+ for (int i = 16; i >= 0; i -= 4)
+ {
+ x76 = rotateWordLeft(x76, 11) - ((x10 & ~x54) + (x32 & x54) + workingKey[i+3]);
+ x54 = rotateWordLeft(x54, 13) - ((x76 & ~x32) + (x10 & x32) + workingKey[i+2]);
+ x32 = rotateWordLeft(x32, 14) - ((x54 & ~x10) + (x76 & x10) + workingKey[i+1]);
+ x10 = rotateWordLeft(x10, 15) - ((x32 & ~x76) + (x54 & x76) + workingKey[i ]);
+ }
+
+ out[outOff + 0] = (byte)x10;
+ out[outOff + 1] = (byte)(x10 >> 8);
+ out[outOff + 2] = (byte)x32;
+ out[outOff + 3] = (byte)(x32 >> 8);
+ out[outOff + 4] = (byte)x54;
+ out[outOff + 5] = (byte)(x54 >> 8);
+ out[outOff + 6] = (byte)x76;
+ out[outOff + 7] = (byte)(x76 >> 8);
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-13 22:34:26 +0000