1 /* GENERATED SOURCE. DO NOT MODIFY. */ 2 package com.android.org.bouncycastle.crypto.engines; 3 4 import com.android.org.bouncycastle.crypto.BlockCipher; 5 import com.android.org.bouncycastle.crypto.CipherParameters; 6 import com.android.org.bouncycastle.crypto.DataLengthException; 7 import com.android.org.bouncycastle.crypto.OutputLengthException; 8 import com.android.org.bouncycastle.crypto.params.KeyParameter; 9 import com.android.org.bouncycastle.crypto.params.RC2Parameters; 10 11 /** 12 * an implementation of RC2 as described in RFC 2268 13 * "A Description of the RC2(r) Encryption Algorithm" R. Rivest. 14 * @hide This class is not part of the Android public SDK API 15 */ 16 public class RC2Engine 17 implements BlockCipher 18 { 19 // 20 // the values we use for key expansion (based on the digits of PI) 21 // 22 private static byte[] piTable = 23 { 24 (byte)0xd9, (byte)0x78, (byte)0xf9, (byte)0xc4, (byte)0x19, (byte)0xdd, (byte)0xb5, (byte)0xed, 25 (byte)0x28, (byte)0xe9, (byte)0xfd, (byte)0x79, (byte)0x4a, (byte)0xa0, (byte)0xd8, (byte)0x9d, 26 (byte)0xc6, (byte)0x7e, (byte)0x37, (byte)0x83, (byte)0x2b, (byte)0x76, (byte)0x53, (byte)0x8e, 27 (byte)0x62, (byte)0x4c, (byte)0x64, (byte)0x88, (byte)0x44, (byte)0x8b, (byte)0xfb, (byte)0xa2, 28 (byte)0x17, (byte)0x9a, (byte)0x59, (byte)0xf5, (byte)0x87, (byte)0xb3, (byte)0x4f, (byte)0x13, 29 (byte)0x61, (byte)0x45, (byte)0x6d, (byte)0x8d, (byte)0x9, (byte)0x81, (byte)0x7d, (byte)0x32, 30 (byte)0xbd, (byte)0x8f, (byte)0x40, (byte)0xeb, (byte)0x86, (byte)0xb7, (byte)0x7b, (byte)0xb, 31 (byte)0xf0, (byte)0x95, (byte)0x21, (byte)0x22, (byte)0x5c, (byte)0x6b, (byte)0x4e, (byte)0x82, 32 (byte)0x54, (byte)0xd6, (byte)0x65, (byte)0x93, (byte)0xce, (byte)0x60, (byte)0xb2, (byte)0x1c, 33 (byte)0x73, (byte)0x56, (byte)0xc0, (byte)0x14, (byte)0xa7, (byte)0x8c, (byte)0xf1, (byte)0xdc, 34 (byte)0x12, (byte)0x75, (byte)0xca, (byte)0x1f, (byte)0x3b, (byte)0xbe, (byte)0xe4, (byte)0xd1, 35 (byte)0x42, (byte)0x3d, (byte)0xd4, (byte)0x30, (byte)0xa3, (byte)0x3c, (byte)0xb6, (byte)0x26, 36 (byte)0x6f, (byte)0xbf, (byte)0xe, (byte)0xda, (byte)0x46, (byte)0x69, (byte)0x7, (byte)0x57, 37 (byte)0x27, (byte)0xf2, (byte)0x1d, (byte)0x9b, (byte)0xbc, (byte)0x94, (byte)0x43, (byte)0x3, 38 (byte)0xf8, (byte)0x11, (byte)0xc7, (byte)0xf6, (byte)0x90, (byte)0xef, (byte)0x3e, (byte)0xe7, 39 (byte)0x6, (byte)0xc3, (byte)0xd5, (byte)0x2f, (byte)0xc8, (byte)0x66, (byte)0x1e, (byte)0xd7, 40 (byte)0x8, (byte)0xe8, (byte)0xea, (byte)0xde, (byte)0x80, (byte)0x52, (byte)0xee, (byte)0xf7, 41 (byte)0x84, (byte)0xaa, (byte)0x72, (byte)0xac, (byte)0x35, (byte)0x4d, (byte)0x6a, (byte)0x2a, 42 (byte)0x96, (byte)0x1a, (byte)0xd2, (byte)0x71, (byte)0x5a, (byte)0x15, (byte)0x49, (byte)0x74, 43 (byte)0x4b, (byte)0x9f, (byte)0xd0, (byte)0x5e, (byte)0x4, (byte)0x18, (byte)0xa4, (byte)0xec, 44 (byte)0xc2, (byte)0xe0, (byte)0x41, (byte)0x6e, (byte)0xf, (byte)0x51, (byte)0xcb, (byte)0xcc, 45 (byte)0x24, (byte)0x91, (byte)0xaf, (byte)0x50, (byte)0xa1, (byte)0xf4, (byte)0x70, (byte)0x39, 46 (byte)0x99, (byte)0x7c, (byte)0x3a, (byte)0x85, (byte)0x23, (byte)0xb8, (byte)0xb4, (byte)0x7a, 47 (byte)0xfc, (byte)0x2, (byte)0x36, (byte)0x5b, (byte)0x25, (byte)0x55, (byte)0x97, (byte)0x31, 48 (byte)0x2d, (byte)0x5d, (byte)0xfa, (byte)0x98, (byte)0xe3, (byte)0x8a, (byte)0x92, (byte)0xae, 49 (byte)0x5, (byte)0xdf, (byte)0x29, (byte)0x10, (byte)0x67, (byte)0x6c, (byte)0xba, (byte)0xc9, 50 (byte)0xd3, (byte)0x0, (byte)0xe6, (byte)0xcf, (byte)0xe1, (byte)0x9e, (byte)0xa8, (byte)0x2c, 51 (byte)0x63, (byte)0x16, (byte)0x1, (byte)0x3f, (byte)0x58, (byte)0xe2, (byte)0x89, (byte)0xa9, 52 (byte)0xd, (byte)0x38, (byte)0x34, (byte)0x1b, (byte)0xab, (byte)0x33, (byte)0xff, (byte)0xb0, 53 (byte)0xbb, (byte)0x48, (byte)0xc, (byte)0x5f, (byte)0xb9, (byte)0xb1, (byte)0xcd, (byte)0x2e, 54 (byte)0xc5, (byte)0xf3, (byte)0xdb, (byte)0x47, (byte)0xe5, (byte)0xa5, (byte)0x9c, (byte)0x77, 55 (byte)0xa, (byte)0xa6, (byte)0x20, (byte)0x68, (byte)0xfe, (byte)0x7f, (byte)0xc1, (byte)0xad 56 }; 57 58 private static final int BLOCK_SIZE = 8; 59 60 private int[] workingKey; 61 private boolean encrypting; 62 63 private int[] generateWorkingKey( 64 byte[] key, 65 int bits) 66 { 67 int x; 68 int[] xKey = new int[128]; 69 70 for (int i = 0; i != key.length; i++) 71 { 72 xKey[i] = key[i] & 0xff; 73 } 74 75 // Phase 1: Expand input key to 128 bytes 76 int len = key.length; 77 78 if (len < 128) 79 { 80 int index = 0; 81 82 x = xKey[len - 1]; 83 84 do 85 { 86 x = piTable[(x + xKey[index++]) & 255] & 0xff; 87 xKey[len++] = x; 88 } 89 while (len < 128); 90 } 91 92 // Phase 2 - reduce effective key size to "bits" 93 len = (bits + 7) >> 3; 94 x = piTable[xKey[128 - len] & (255 >> (7 & -bits))] & 0xff; 95 xKey[128 - len] = x; 96 97 for (int i = 128 - len - 1; i >= 0; i--) 98 { 99 x = piTable[x ^ xKey[i + len]] & 0xff; 100 xKey[i] = x; 101 } 102 103 // Phase 3 - copy to newKey in little-endian order 104 int[] newKey = new int[64]; 105 106 for (int i = 0; i != newKey.length; i++) 107 { 108 newKey[i] = (xKey[2 * i] + (xKey[2 * i + 1] << 8)); 109 } 110 111 return newKey; 112 } 113 114 /** 115 * initialise a RC2 cipher. 116 * 117 * @param encrypting whether or not we are for encryption. 118 * @param params the parameters required to set up the cipher. 119 * @exception IllegalArgumentException if the params argument is 120 * inappropriate. 121 */ 122 public void init( 123 boolean encrypting, 124 CipherParameters params) 125 { 126 this.encrypting = encrypting; 127 128 if (params instanceof RC2Parameters) 129 { 130 RC2Parameters param = (RC2Parameters)params; 131 132 workingKey = generateWorkingKey(param.getKey(), 133 param.getEffectiveKeyBits()); 134 } 135 else if (params instanceof KeyParameter) 136 { 137 byte[] key = ((KeyParameter)params).getKey(); 138 139 workingKey = generateWorkingKey(key, key.length * 8); 140 } 141 else 142 { 143 throw new IllegalArgumentException("invalid parameter passed to RC2 init - " + params.getClass().getName()); 144 } 145 146 } 147 148 public void reset() 149 { 150 } 151 152 public String getAlgorithmName() 153 { 154 return "RC2"; 155 } 156 157 public int getBlockSize() 158 { 159 return BLOCK_SIZE; 160 } 161 162 public final int processBlock( 163 byte[] in, 164 int inOff, 165 byte[] out, 166 int outOff) 167 { 168 if (workingKey == null) 169 { 170 throw new IllegalStateException("RC2 engine not initialised"); 171 } 172 173 if ((inOff + BLOCK_SIZE) > in.length) 174 { 175 throw new DataLengthException("input buffer too short"); 176 } 177 178 if ((outOff + BLOCK_SIZE) > out.length) 179 { 180 throw new OutputLengthException("output buffer too short"); 181 } 182 183 if (encrypting) 184 { 185 encryptBlock(in, inOff, out, outOff); 186 } 187 else 188 { 189 decryptBlock(in, inOff, out, outOff); 190 } 191 192 return BLOCK_SIZE; 193 } 194 195 /** 196 * return the result rotating the 16 bit number in x left by y 197 */ 198 private int rotateWordLeft( 199 int x, 200 int y) 201 { 202 x &= 0xffff; 203 return (x << y) | (x >> (16 - y)); 204 } 205 206 private void encryptBlock( 207 byte[] in, 208 int inOff, 209 byte[] out, 210 int outOff) 211 { 212 int x76, x54, x32, x10; 213 214 x76 = ((in[inOff + 7] & 0xff) << 8) + (in[inOff + 6] & 0xff); 215 x54 = ((in[inOff + 5] & 0xff) << 8) + (in[inOff + 4] & 0xff); 216 x32 = ((in[inOff + 3] & 0xff) << 8) + (in[inOff + 2] & 0xff); 217 x10 = ((in[inOff + 1] & 0xff) << 8) + (in[inOff + 0] & 0xff); 218 219 for (int i = 0; i <= 16; i += 4) 220 { 221 x10 = rotateWordLeft(x10 + (x32 & ~x76) + (x54 & x76) + workingKey[i ], 1); 222 x32 = rotateWordLeft(x32 + (x54 & ~x10) + (x76 & x10) + workingKey[i+1], 2); 223 x54 = rotateWordLeft(x54 + (x76 & ~x32) + (x10 & x32) + workingKey[i+2], 3); 224 x76 = rotateWordLeft(x76 + (x10 & ~x54) + (x32 & x54) + workingKey[i+3], 5); 225 } 226 227 x10 += workingKey[x76 & 63]; 228 x32 += workingKey[x10 & 63]; 229 x54 += workingKey[x32 & 63]; 230 x76 += workingKey[x54 & 63]; 231 232 for (int i = 20; i <= 40; i += 4) 233 { 234 x10 = rotateWordLeft(x10 + (x32 & ~x76) + (x54 & x76) + workingKey[i ], 1); 235 x32 = rotateWordLeft(x32 + (x54 & ~x10) + (x76 & x10) + workingKey[i+1], 2); 236 x54 = rotateWordLeft(x54 + (x76 & ~x32) + (x10 & x32) + workingKey[i+2], 3); 237 x76 = rotateWordLeft(x76 + (x10 & ~x54) + (x32 & x54) + workingKey[i+3], 5); 238 } 239 240 x10 += workingKey[x76 & 63]; 241 x32 += workingKey[x10 & 63]; 242 x54 += workingKey[x32 & 63]; 243 x76 += workingKey[x54 & 63]; 244 245 for (int i = 44; i < 64; i += 4) 246 { 247 x10 = rotateWordLeft(x10 + (x32 & ~x76) + (x54 & x76) + workingKey[i ], 1); 248 x32 = rotateWordLeft(x32 + (x54 & ~x10) + (x76 & x10) + workingKey[i+1], 2); 249 x54 = rotateWordLeft(x54 + (x76 & ~x32) + (x10 & x32) + workingKey[i+2], 3); 250 x76 = rotateWordLeft(x76 + (x10 & ~x54) + (x32 & x54) + workingKey[i+3], 5); 251 } 252 253 out[outOff + 0] = (byte)x10; 254 out[outOff + 1] = (byte)(x10 >> 8); 255 out[outOff + 2] = (byte)x32; 256 out[outOff + 3] = (byte)(x32 >> 8); 257 out[outOff + 4] = (byte)x54; 258 out[outOff + 5] = (byte)(x54 >> 8); 259 out[outOff + 6] = (byte)x76; 260 out[outOff + 7] = (byte)(x76 >> 8); 261 } 262 263 private void decryptBlock( 264 byte[] in, 265 int inOff, 266 byte[] out, 267 int outOff) 268 { 269 int x76, x54, x32, x10; 270 271 x76 = ((in[inOff + 7] & 0xff) << 8) + (in[inOff + 6] & 0xff); 272 x54 = ((in[inOff + 5] & 0xff) << 8) + (in[inOff + 4] & 0xff); 273 x32 = ((in[inOff + 3] & 0xff) << 8) + (in[inOff + 2] & 0xff); 274 x10 = ((in[inOff + 1] & 0xff) << 8) + (in[inOff + 0] & 0xff); 275 276 for (int i = 60; i >= 44; i -= 4) 277 { 278 x76 = rotateWordLeft(x76, 11) - ((x10 & ~x54) + (x32 & x54) + workingKey[i+3]); 279 x54 = rotateWordLeft(x54, 13) - ((x76 & ~x32) + (x10 & x32) + workingKey[i+2]); 280 x32 = rotateWordLeft(x32, 14) - ((x54 & ~x10) + (x76 & x10) + workingKey[i+1]); 281 x10 = rotateWordLeft(x10, 15) - ((x32 & ~x76) + (x54 & x76) + workingKey[i ]); 282 } 283 284 x76 -= workingKey[x54 & 63]; 285 x54 -= workingKey[x32 & 63]; 286 x32 -= workingKey[x10 & 63]; 287 x10 -= workingKey[x76 & 63]; 288 289 for (int i = 40; i >= 20; i -= 4) 290 { 291 x76 = rotateWordLeft(x76, 11) - ((x10 & ~x54) + (x32 & x54) + workingKey[i+3]); 292 x54 = rotateWordLeft(x54, 13) - ((x76 & ~x32) + (x10 & x32) + workingKey[i+2]); 293 x32 = rotateWordLeft(x32, 14) - ((x54 & ~x10) + (x76 & x10) + workingKey[i+1]); 294 x10 = rotateWordLeft(x10, 15) - ((x32 & ~x76) + (x54 & x76) + workingKey[i ]); 295 } 296 297 x76 -= workingKey[x54 & 63]; 298 x54 -= workingKey[x32 & 63]; 299 x32 -= workingKey[x10 & 63]; 300 x10 -= workingKey[x76 & 63]; 301 302 for (int i = 16; i >= 0; i -= 4) 303 { 304 x76 = rotateWordLeft(x76, 11) - ((x10 & ~x54) + (x32 & x54) + workingKey[i+3]); 305 x54 = rotateWordLeft(x54, 13) - ((x76 & ~x32) + (x10 & x32) + workingKey[i+2]); 306 x32 = rotateWordLeft(x32, 14) - ((x54 & ~x10) + (x76 & x10) + workingKey[i+1]); 307 x10 = rotateWordLeft(x10, 15) - ((x32 & ~x76) + (x54 & x76) + workingKey[i ]); 308 } 309 310 out[outOff + 0] = (byte)x10; 311 out[outOff + 1] = (byte)(x10 >> 8); 312 out[outOff + 2] = (byte)x32; 313 out[outOff + 3] = (byte)(x32 >> 8); 314 out[outOff + 4] = (byte)x54; 315 out[outOff + 5] = (byte)(x54 >> 8); 316 out[outOff + 6] = (byte)x76; 317 out[outOff + 7] = (byte)(x76 >> 8); 318 } 319 } 320
