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| 1 | +package org.unify4j.common; |
| 2 | + |
| 3 | +import javax.crypto.Cipher; |
| 4 | +import javax.crypto.spec.IvParameterSpec; |
| 5 | +import javax.crypto.spec.SecretKeySpec; |
| 6 | +import java.io.File; |
| 7 | +import java.io.FileInputStream; |
| 8 | +import java.io.IOException; |
| 9 | +import java.nio.ByteBuffer; |
| 10 | +import java.nio.channels.FileChannel; |
| 11 | +import java.nio.charset.StandardCharsets; |
| 12 | +import java.security.Key; |
| 13 | +import java.security.MessageDigest; |
| 14 | +import java.security.NoSuchAlgorithmException; |
| 15 | +import java.security.spec.AlgorithmParameterSpec; |
| 16 | +import java.util.Objects; |
| 17 | + |
| 18 | +public class Encryption4j { |
| 19 | + |
| 20 | + /** |
| 21 | + * Computes the MD5 hash of a file using a FileChannel and a direct ByteBuffer. |
| 22 | + * |
| 23 | + * @param file the file for which to compute the MD5 hash |
| 24 | + * @return the MD5 hash of the file as a hexadecimal string, or null if an error occurs |
| 25 | + */ |
| 26 | + public static String fastMD5(File file) { |
| 27 | + try (FileInputStream in = new FileInputStream(file)) { |
| 28 | + return calculateFileHash(in.getChannel(), getMD5Digest()); |
| 29 | + } catch (IOException e) { |
| 30 | + return null; |
| 31 | + } |
| 32 | + } |
| 33 | + |
| 34 | + /** |
| 35 | + * Computes the SHA-1 hash of a file using a FileChannel and a direct ByteBuffer. |
| 36 | + * |
| 37 | + * @param file the file for which to compute the SHA-1 hash |
| 38 | + * @return the SHA-1 hash of the file as a hexadecimal string, or null if an error occurs |
| 39 | + */ |
| 40 | + public static String fastSHA1(File file) { |
| 41 | + try (FileInputStream in = new FileInputStream(file)) { |
| 42 | + return calculateFileHash(in.getChannel(), getSHA1Digest()); |
| 43 | + } catch (IOException e) { |
| 44 | + return null; |
| 45 | + } |
| 46 | + } |
| 47 | + |
| 48 | + /** |
| 49 | + * Computes the SHA-256 hash of a file using a FileChannel and a direct ByteBuffer. |
| 50 | + * |
| 51 | + * @param file the file for which to compute the SHA-256 hash |
| 52 | + * @return the SHA-256 hash of the file as a hexadecimal string, or null if an error occurs |
| 53 | + */ |
| 54 | + public static String fastSHA256(File file) { |
| 55 | + try (FileInputStream in = new FileInputStream(file)) { |
| 56 | + return calculateFileHash(in.getChannel(), getSHA256Digest()); |
| 57 | + } catch (IOException e) { |
| 58 | + return null; |
| 59 | + } |
| 60 | + } |
| 61 | + |
| 62 | + /** |
| 63 | + * Computes the SHA-512 hash of a file using a FileChannel and a direct ByteBuffer. |
| 64 | + * |
| 65 | + * @param file the file for which to compute the SHA-512 hash |
| 66 | + * @return the SHA-512 hash of the file as a hexadecimal string, or null if an error occurs |
| 67 | + */ |
| 68 | + public static String fastSHA512(File file) { |
| 69 | + try (FileInputStream in = new FileInputStream(file)) { |
| 70 | + return calculateFileHash(in.getChannel(), getSHA512Digest()); |
| 71 | + } catch (IOException e) { |
| 72 | + return null; |
| 73 | + } |
| 74 | + } |
| 75 | + |
| 76 | + /** |
| 77 | + * Calculates the hash of a file using a given MessageDigest. |
| 78 | + * |
| 79 | + * @param ch the FileChannel to read from |
| 80 | + * @param d the MessageDigest to update with the file data |
| 81 | + * @return the hash of the file as a hexadecimal string |
| 82 | + * @throws IOException if an I/O error occurs |
| 83 | + */ |
| 84 | + public static String calculateFileHash(FileChannel ch, MessageDigest d) throws IOException { |
| 85 | + ByteBuffer bb = ByteBuffer.allocateDirect(65536); |
| 86 | + int nRead; |
| 87 | + while ((nRead = ch.read(bb)) != -1) { |
| 88 | + if (nRead == 0) { |
| 89 | + continue; |
| 90 | + } |
| 91 | + bb.position(0); |
| 92 | + bb.limit(nRead); |
| 93 | + d.update(bb); |
| 94 | + bb.clear(); |
| 95 | + } |
| 96 | + return Byte4j.encode(d.digest()); |
| 97 | + } |
| 98 | + |
| 99 | + /** |
| 100 | + * Calculates the MD5 hash of a byte array. |
| 101 | + * |
| 102 | + * @param bytes the byte array to hash |
| 103 | + * @return the MD5 hash as a hexadecimal string |
| 104 | + */ |
| 105 | + public static String calculateMD5Hash(byte[] bytes) { |
| 106 | + return calculateHash(getMD5Digest(), bytes); |
| 107 | + } |
| 108 | + |
| 109 | + /** |
| 110 | + * Returns a MessageDigest instance for the specified algorithm. |
| 111 | + * |
| 112 | + * @param digest the name of the algorithm |
| 113 | + * @return the MessageDigest instance |
| 114 | + * @throws IllegalArgumentException if the algorithm is not available |
| 115 | + */ |
| 116 | + public static MessageDigest getDigest(String digest) { |
| 117 | + try { |
| 118 | + return MessageDigest.getInstance(digest); |
| 119 | + } catch (NoSuchAlgorithmException e) { |
| 120 | + throw new IllegalArgumentException(String.format("The requested MessageDigest (%s) does not exist", digest), e); |
| 121 | + } |
| 122 | + |
| 123 | + } |
| 124 | + |
| 125 | + /** |
| 126 | + * Returns a MessageDigest instance for MD5. |
| 127 | + * |
| 128 | + * @return the MD5 MessageDigest instance |
| 129 | + */ |
| 130 | + public static MessageDigest getMD5Digest() { |
| 131 | + return getDigest("MD5"); |
| 132 | + } |
| 133 | + |
| 134 | + /** |
| 135 | + * Calculates the SHA-1 hash of a byte array. |
| 136 | + * |
| 137 | + * @param bytes the byte array to hash |
| 138 | + * @return the SHA-1 hash as a hexadecimal string |
| 139 | + */ |
| 140 | + public static String calculateSHA1Hash(byte[] bytes) { |
| 141 | + return calculateHash(getSHA1Digest(), bytes); |
| 142 | + } |
| 143 | + |
| 144 | + /** |
| 145 | + * Returns a MessageDigest instance for SHA-1. |
| 146 | + * |
| 147 | + * @return the SHA-1 MessageDigest instance |
| 148 | + */ |
| 149 | + public static MessageDigest getSHA1Digest() { |
| 150 | + return getDigest("SHA-1"); |
| 151 | + } |
| 152 | + |
| 153 | + /** |
| 154 | + * Calculates the SHA-256 hash of a byte array. |
| 155 | + * |
| 156 | + * @param bytes the byte array to hash |
| 157 | + * @return the SHA-256 hash as a hexadecimal string |
| 158 | + */ |
| 159 | + public static String calculateSHA256Hash(byte[] bytes) { |
| 160 | + return calculateHash(getSHA256Digest(), bytes); |
| 161 | + } |
| 162 | + |
| 163 | + /** |
| 164 | + * Returns a MessageDigest instance for SHA-256. |
| 165 | + * |
| 166 | + * @return the SHA-256 MessageDigest instance |
| 167 | + */ |
| 168 | + public static MessageDigest getSHA256Digest() { |
| 169 | + return getDigest("SHA-256"); |
| 170 | + } |
| 171 | + |
| 172 | + /** |
| 173 | + * Calculates the SHA-512 hash of a byte array. |
| 174 | + * |
| 175 | + * @param bytes the byte array to hash |
| 176 | + * @return the SHA-512 hash as a hexadecimal string |
| 177 | + */ |
| 178 | + public static String calculateSHA512Hash(byte[] bytes) { |
| 179 | + return calculateHash(getSHA512Digest(), bytes); |
| 180 | + } |
| 181 | + |
| 182 | + /** |
| 183 | + * Returns a MessageDigest instance for SHA-512. |
| 184 | + * |
| 185 | + * @return the SHA-512 MessageDigest instance |
| 186 | + */ |
| 187 | + public static MessageDigest getSHA512Digest() { |
| 188 | + return getDigest("SHA-512"); |
| 189 | + } |
| 190 | + |
| 191 | + /** |
| 192 | + * Creates a byte array suitable for use as an encryption key from a string key. |
| 193 | + * |
| 194 | + * @param key the string key |
| 195 | + * @param bitsNeeded the number of bits needed for the encryption key |
| 196 | + * @return the byte array of the encryption key |
| 197 | + */ |
| 198 | + public static byte[] createCipherBytes(String key, int bitsNeeded) { |
| 199 | + String word = calculateMD5Hash(key.getBytes(StandardCharsets.UTF_8)); |
| 200 | + return word.substring(0, bitsNeeded / 8).getBytes(StandardCharsets.UTF_8); |
| 201 | + } |
| 202 | + |
| 203 | + /** |
| 204 | + * Creates an AES encryption cipher using a given key. |
| 205 | + * |
| 206 | + * @param key the encryption key |
| 207 | + * @return the AES encryption cipher |
| 208 | + * @throws Exception if an error occurs creating the cipher |
| 209 | + */ |
| 210 | + public static Cipher createAesEncryptionCipher(String key) throws Exception { |
| 211 | + return createAesCipher(key, Cipher.ENCRYPT_MODE); |
| 212 | + } |
| 213 | + |
| 214 | + /** |
| 215 | + * Creates an AES decryption cipher using a given key. |
| 216 | + * |
| 217 | + * @param key the decryption key |
| 218 | + * @return the AES decryption cipher |
| 219 | + * @throws Exception if an error occurs creating the cipher |
| 220 | + */ |
| 221 | + public static Cipher createAesDecryptionCipher(String key) throws Exception { |
| 222 | + return createAesCipher(key, Cipher.DECRYPT_MODE); |
| 223 | + } |
| 224 | + |
| 225 | + /** |
| 226 | + * Creates an AES cipher using a given key and mode. |
| 227 | + * |
| 228 | + * @param key the encryption/decryption key |
| 229 | + * @param mode the cipher mode (Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE) |
| 230 | + * @return the AES cipher |
| 231 | + * @throws Exception if an error occurs creating the cipher |
| 232 | + */ |
| 233 | + public static Cipher createAesCipher(String key, int mode) throws Exception { |
| 234 | + Key sKey = new SecretKeySpec(createCipherBytes(key, 128), "AES"); |
| 235 | + return createAesCipher(sKey, mode); |
| 236 | + } |
| 237 | + |
| 238 | + /** |
| 239 | + * Creates a Cipher from the passed in key, using the passed in mode. |
| 240 | + * |
| 241 | + * @param key the SecretKeySpec |
| 242 | + * @param mode the cipher mode (Cipher.ENCRYPT_MODE or Cipher.DECRYPT_MODE) |
| 243 | + * @return the Cipher instance |
| 244 | + * @throws Exception if an error occurs creating the cipher |
| 245 | + */ |
| 246 | + public static Cipher createAesCipher(Key key, int mode) throws Exception { |
| 247 | + MessageDigest d = getMD5Digest(); // Use password key as seed for IV (must be 16 bytes) |
| 248 | + d.update(key.getEncoded()); |
| 249 | + byte[] iv = d.digest(); |
| 250 | + AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv); |
| 251 | + Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); // CBC faster than CFB8/NoPadding (but file length changes) |
| 252 | + cipher.init(mode, key, paramSpec); |
| 253 | + return cipher; |
| 254 | + } |
| 255 | + |
| 256 | + /** |
| 257 | + * Encrypts a string using AES-128 and returns the encrypted content as a hexadecimal string. |
| 258 | + * |
| 259 | + * @param key the encryption key |
| 260 | + * @param content the content to be encrypted |
| 261 | + * @return the encrypted content as a hexadecimal string |
| 262 | + */ |
| 263 | + public static String encrypt(String key, String content) { |
| 264 | + try { |
| 265 | + return Byte4j.encode(createAesEncryptionCipher(key).doFinal(content.getBytes(StandardCharsets.UTF_8))); |
| 266 | + } catch (Exception e) { |
| 267 | + throw new IllegalStateException("Error occurred encrypting data", e); |
| 268 | + } |
| 269 | + } |
| 270 | + |
| 271 | + /** |
| 272 | + * Encrypts a byte array using AES-128 and returns the encrypted content as a hexadecimal string. |
| 273 | + * |
| 274 | + * @param key the encryption key |
| 275 | + * @param content the byte array to be encrypted |
| 276 | + * @return the encrypted content as a hexadecimal string |
| 277 | + */ |
| 278 | + public static String encryptBytes(String key, byte[] content) { |
| 279 | + try { |
| 280 | + return Byte4j.encode(createAesEncryptionCipher(key).doFinal(content)); |
| 281 | + } catch (Exception e) { |
| 282 | + throw new IllegalStateException("Error occurred encrypting data", e); |
| 283 | + } |
| 284 | + } |
| 285 | + |
| 286 | + /** |
| 287 | + * Decrypts a hexadecimal string using AES-128 and returns the original content as a string. |
| 288 | + * |
| 289 | + * @param key the decryption key |
| 290 | + * @param hexStr the encrypted content as a hexadecimal string |
| 291 | + * @return the original content as a string |
| 292 | + */ |
| 293 | + public static String decrypt(String key, String hexStr) { |
| 294 | + try { |
| 295 | + return new String(createAesDecryptionCipher(key).doFinal(Objects.requireNonNull(Byte4j.decode(hexStr)))); |
| 296 | + } catch (Exception e) { |
| 297 | + throw new IllegalStateException("Error occurred decrypting data", e); |
| 298 | + } |
| 299 | + } |
| 300 | + |
| 301 | + /** |
| 302 | + * Decrypts a hexadecimal string using AES-128 and returns the original content as a byte array. |
| 303 | + * |
| 304 | + * @param key the decryption key |
| 305 | + * @param hexStr the encrypted content as a hexadecimal string |
| 306 | + * @return the original content as a byte array |
| 307 | + */ |
| 308 | + public static byte[] decryptBytes(String key, String hexStr) { |
| 309 | + try { |
| 310 | + return createAesDecryptionCipher(key).doFinal(Objects.requireNonNull(Byte4j.decode(hexStr))); |
| 311 | + } catch (Exception e) { |
| 312 | + throw new IllegalStateException("Error occurred decrypting data", e); |
| 313 | + } |
| 314 | + } |
| 315 | + |
| 316 | + /** |
| 317 | + * Calculates a hash from a byte array using a given MessageDigest. |
| 318 | + * |
| 319 | + * @param d the MessageDigest to update |
| 320 | + * @param bytes the byte array to hash |
| 321 | + * @return the hash as a hexadecimal string |
| 322 | + */ |
| 323 | + public static String calculateHash(MessageDigest d, byte[] bytes) { |
| 324 | + if (bytes == null) { |
| 325 | + return null; |
| 326 | + } |
| 327 | + d.update(bytes); |
| 328 | + return Byte4j.encode(d.digest()); |
| 329 | + } |
| 330 | +} |
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