| 1 | package be.nikiroo.utils; |
| 2 | |
| 3 | import java.io.IOException; |
| 4 | import java.security.InvalidKeyException; |
| 5 | import java.security.NoSuchAlgorithmException; |
| 6 | |
| 7 | import javax.crypto.BadPaddingException; |
| 8 | import javax.crypto.Cipher; |
| 9 | import javax.crypto.IllegalBlockSizeException; |
| 10 | import javax.crypto.NoSuchPaddingException; |
| 11 | import javax.crypto.SecretKey; |
| 12 | import javax.crypto.spec.SecretKeySpec; |
| 13 | |
| 14 | /** |
| 15 | * Small utility class to do AES encryption/decryption. |
| 16 | * <p> |
| 17 | * Do not assume it is actually secure until you checked the code... |
| 18 | * |
| 19 | * @author niki |
| 20 | */ |
| 21 | public class CryptUtils { |
| 22 | private Cipher ecipher; |
| 23 | private Cipher dcipher; |
| 24 | |
| 25 | /** |
| 26 | * Small and leazy way to initialize a 128 bits key with {@link CryptUtils}. |
| 27 | * <p> |
| 28 | * <b>Some</b> part of the key will be used to generate a 128 bits key and |
| 29 | * initialize the {@link CryptUtils}; even NULL will generate something. |
| 30 | * <p> |
| 31 | * <b>This is most probably not secure. Do not use if you actually care |
| 32 | * about security.</b> |
| 33 | * |
| 34 | * @param key |
| 35 | * the {@link String} to use as a base for the key, can be NULL |
| 36 | */ |
| 37 | public CryptUtils(String key) { |
| 38 | try { |
| 39 | init(key2key(key)); |
| 40 | } catch (InvalidKeyException e) { |
| 41 | // We made sure that the key is correct, so nothing here |
| 42 | e.printStackTrace(); |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * Create a new instance of {@link CryptUtils} with the given 128 bytes key. |
| 48 | * <p> |
| 49 | * The key <b>must</b> be exactly 128 bytes long. |
| 50 | * |
| 51 | * @param bytes32 |
| 52 | * the 128 bits (32 bytes) of the key |
| 53 | * |
| 54 | * @throws InvalidKeyException |
| 55 | * if the key is not an array of 128 bytes |
| 56 | */ |
| 57 | public CryptUtils(byte[] bytes32) throws InvalidKeyException { |
| 58 | init(bytes32); |
| 59 | } |
| 60 | |
| 61 | /** |
| 62 | * This method required an array of 128 bytes. |
| 63 | * |
| 64 | * @param bytes32 |
| 65 | * the array, which <b>must</b> be of 128 bits (32 bytes) |
| 66 | * |
| 67 | * @throws InvalidKeyException |
| 68 | * if the key is not an array of 128 bits (32 bytes) |
| 69 | */ |
| 70 | private void init(byte[] bytes32) throws InvalidKeyException { |
| 71 | if (bytes32 == null || bytes32.length != 32) { |
| 72 | throw new InvalidKeyException( |
| 73 | "The size of the key must be of 128 bits (32 bytes), it is: " |
| 74 | + (bytes32 == null ? "null" : "" + bytes32.length) |
| 75 | + " bytes"); |
| 76 | } |
| 77 | |
| 78 | SecretKey key = new SecretKeySpec(bytes32, "AES"); |
| 79 | try { |
| 80 | ecipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); |
| 81 | dcipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); |
| 82 | ecipher.init(Cipher.ENCRYPT_MODE, key); |
| 83 | dcipher.init(Cipher.DECRYPT_MODE, key); |
| 84 | } catch (NoSuchAlgorithmException e) { |
| 85 | // Every implementation of the Java platform is required to support |
| 86 | // this standard Cipher transformation with 128 bits keys |
| 87 | e.printStackTrace(); |
| 88 | } catch (NoSuchPaddingException e) { |
| 89 | // Every implementation of the Java platform is required to support |
| 90 | // this standard Cipher transformation with 128 bits keys |
| 91 | e.printStackTrace(); |
| 92 | } catch (InvalidKeyException e) { |
| 93 | // Every implementation of the Java platform is required to support |
| 94 | // this standard Cipher transformation with 128 bits keys |
| 95 | e.printStackTrace(); |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Encrypt the data. |
| 101 | * |
| 102 | * @param data |
| 103 | * the data to encrypt |
| 104 | * |
| 105 | * @return the encrypted data |
| 106 | * |
| 107 | * @throws IOException |
| 108 | * in case of I/O error (i.e., the data is not what you assumed |
| 109 | * it was) |
| 110 | */ |
| 111 | public byte[] encrypt(byte[] data) throws IOException { |
| 112 | try { |
| 113 | return ecipher.doFinal(data); |
| 114 | } catch (IllegalBlockSizeException e) { |
| 115 | throw new IOException(e); |
| 116 | } catch (BadPaddingException e) { |
| 117 | throw new IOException(e); |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | /** |
| 122 | * Encrypt the data. |
| 123 | * |
| 124 | * @param data |
| 125 | * the data to encrypt |
| 126 | * |
| 127 | * @return the encrypted data |
| 128 | * |
| 129 | * @throws IOException |
| 130 | * in case of I/O error (i.e., the data is not what you assumed |
| 131 | * it was) |
| 132 | */ |
| 133 | public byte[] encrypt(String data) throws IOException { |
| 134 | return encrypt(data.getBytes("UTF8")); |
| 135 | } |
| 136 | |
| 137 | /** |
| 138 | * Encrypt the data, then encode it into Base64. |
| 139 | * |
| 140 | * @param data |
| 141 | * the data to encrypt |
| 142 | * @param zip |
| 143 | * TRUE to also compress the data in GZIP format; remember that |
| 144 | * compressed and not-compressed content are different; you need |
| 145 | * to know which is which when decoding |
| 146 | * |
| 147 | * @return the encrypted data, encoded in Base64 |
| 148 | * |
| 149 | * @throws IOException |
| 150 | * in case of I/O error (i.e., the data is not what you assumed |
| 151 | * it was) |
| 152 | */ |
| 153 | public String encrypt64(String data, boolean zip) throws IOException { |
| 154 | return encrypt64(data.getBytes("UTF8"), zip); |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * Encrypt the data, then encode it into Base64. |
| 159 | * |
| 160 | * @param data |
| 161 | * the data to encrypt |
| 162 | * @param zip |
| 163 | * TRUE to also compress the data in GZIP format; remember that |
| 164 | * compressed and not-compressed content are different; you need |
| 165 | * to know which is which when decoding |
| 166 | * |
| 167 | * @return the encrypted data, encoded in Base64 |
| 168 | * |
| 169 | * @throws IOException |
| 170 | * in case of I/O error (i.e., the data is not what you assumed |
| 171 | * it was) |
| 172 | */ |
| 173 | public String encrypt64(byte[] data, boolean zip) throws IOException { |
| 174 | return StringUtils.base64(encrypt(data), zip); |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Decode the data which is assumed to be encrypted with the same utilities. |
| 179 | * |
| 180 | * @param data |
| 181 | * the encrypted data to decode |
| 182 | * |
| 183 | * @return the original, decoded data |
| 184 | * |
| 185 | * @throws IOException |
| 186 | * in case of I/O error |
| 187 | */ |
| 188 | public byte[] decrypt(byte[] data) throws IOException { |
| 189 | try { |
| 190 | return dcipher.doFinal(data); |
| 191 | } catch (IllegalBlockSizeException e) { |
| 192 | throw new IOException(e); |
| 193 | } catch (BadPaddingException e) { |
| 194 | throw new IOException(e); |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | * Decode the data which is assumed to be encrypted with the same utilities |
| 200 | * and is a Base64 encoded value. |
| 201 | * |
| 202 | * @param data |
| 203 | * the encrypted data to decode in Base64 format |
| 204 | * @param zip |
| 205 | * TRUE to also uncompress the data from a GZIP format |
| 206 | * automatically; if set to FALSE, zipped data can be returned |
| 207 | * |
| 208 | * @return the original, decoded data |
| 209 | * |
| 210 | * @throws IOException |
| 211 | * in case of I/O error |
| 212 | */ |
| 213 | public byte[] decrypt64(String data, boolean zip) throws IOException { |
| 214 | return decrypt(StringUtils.unbase64(data, zip)); |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * Decode the data which is assumed to be encrypted with the same utilities |
| 219 | * and is a Base64 encoded value, then convert it into a String (this method |
| 220 | * assumes the data <b>was</b> indeed a UTF-8 encoded {@link String}). |
| 221 | * |
| 222 | * @param data |
| 223 | * the encrypted data to decode in Base64 format |
| 224 | * @param zip |
| 225 | * TRUE to also uncompress the data from a GZIP format |
| 226 | * automatically; if set to FALSE, zipped data can be returned |
| 227 | * |
| 228 | * @return the original, decoded data |
| 229 | * |
| 230 | * @throws IOException |
| 231 | * in case of I/O error |
| 232 | */ |
| 233 | public String decrypt64s(String data, boolean zip) throws IOException { |
| 234 | return new String(decrypt(StringUtils.unbase64(data, zip)), "UTF-8"); |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * This is probably <b>NOT</b> secure! |
| 239 | * |
| 240 | * @param input |
| 241 | * some {@link String} input |
| 242 | * |
| 243 | * @return a 128 bits key computed from the given input |
| 244 | */ |
| 245 | static private byte[] key2key(String input) { |
| 246 | return StringUtils.getMd5Hash(input).getBytes(); |
| 247 | } |
| 248 | } |