Complex classes like PassHash often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use PassHash, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 14 | class PassHash { | 
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| 15 | /**  | 
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| 16 | * Verifies a cleartext password against a crypted hash  | 
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| 17 | *  | 
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| 18 | * The method and salt used for the crypted hash is determined automatically,  | 
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| 19 | * then the clear text password is crypted using the same method. If both hashs  | 
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| 20 | * match true is is returned else false  | 
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| 21 | *  | 
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| 22 | * @author Andreas Gohr <[email protected]>  | 
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| 23 | *  | 
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| 24 | * @param string $clear Clear-Text password  | 
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| 25 | * @param string $hash Hash to compare against  | 
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| 26 | * @return bool  | 
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| 27 | */  | 
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| 28 |     public function verify_hash($clear, $hash) { | 
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| 104 | |||
| 105 | /**  | 
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| 106 | * Create a random salt  | 
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| 107 | *  | 
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| 108 | * @param int $len The length of the salt  | 
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| 109 | * @return string  | 
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| 110 | */  | 
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| 111 |     public function gen_salt($len = 32) { | 
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| 119 | |||
| 120 | /**  | 
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| 121 | * Initialize the passed variable with a salt if needed.  | 
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| 122 | *  | 
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| 123 | * If $salt is not null, the value is kept, but the lenght restriction is  | 
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| 124 | * applied (unless, $cut is false).  | 
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| 125 | *  | 
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| 126 | * @param string|null &$salt The salt, pass null if you want one generated  | 
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| 127 | * @param int $len The length of the salt  | 
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| 128 | * @param bool $cut Apply length restriction to existing salt?  | 
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| 129 | */  | 
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| 130 |     public function init_salt(&$salt, $len = 32, $cut = true) { | 
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| 137 | |||
| 138 | // Password hashing methods follow below  | 
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| 139 | |||
| 140 | /**  | 
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| 141 | * Password hashing method 'smd5'  | 
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| 142 | *  | 
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| 143 | * Uses salted MD5 hashs. Salt is 8 bytes long.  | 
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| 144 | *  | 
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| 145 | * The same mechanism is used by Apache's 'apr1' method. This will  | 
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| 146 | * fallback to a implementation in pure PHP if MD5 support is not  | 
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| 147 | * available in crypt()  | 
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| 148 | *  | 
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| 149 | * @author Andreas Gohr <[email protected]>  | 
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| 150 | * @author <mikey_nich at hotmail dot com>  | 
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| 151 | * @link http://php.net/manual/en/function.crypt.php#73619  | 
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| 152 | *  | 
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| 153 | * @param string $clear The clear text to hash  | 
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| 154 | * @param string $salt The salt to use, null for random  | 
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| 155 | * @return string Hashed password  | 
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| 156 | */  | 
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| 157 |     public function hash_smd5($clear, $salt = null) { | 
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| 167 | |||
| 168 | /**  | 
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| 169 | * Password hashing method 'lsmd5'  | 
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| 170 | *  | 
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| 171 | * Uses salted MD5 hashs. Salt is 8 bytes long.  | 
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| 172 | *  | 
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| 173 | * This is the format used by LDAP.  | 
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| 174 | *  | 
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| 175 | * @param string $clear The clear text to hash  | 
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| 176 | * @param string $salt The salt to use, null for random  | 
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| 177 | * @return string Hashed password  | 
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| 178 | */  | 
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| 179 |     public function hash_lsmd5($clear, $salt = null) { | 
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| 183 | |||
| 184 | /**  | 
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| 185 | * Password hashing method 'apr1'  | 
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| 186 | *  | 
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| 187 | * Uses salted MD5 hashs. Salt is 8 bytes long.  | 
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| 188 | *  | 
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| 189 | * This is basically the same as smd1 above, but as used by Apache.  | 
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| 190 | *  | 
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| 191 | * @author <mikey_nich at hotmail dot com>  | 
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| 192 | * @link http://php.net/manual/en/function.crypt.php#73619  | 
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| 193 | *  | 
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| 194 | * @param string $clear The clear text to hash  | 
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| 195 | * @param string $salt The salt to use, null for random  | 
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| 196 | * @param string $magic The hash identifier (apr1 or 1)  | 
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| 197 | * @return string Hashed password  | 
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| 198 | */  | 
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| 199 |     public function hash_apr1($clear, $salt = null, $magic = 'apr1') { | 
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| 234 | |||
| 235 | /**  | 
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| 236 | * Password hashing method 'md5'  | 
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| 237 | *  | 
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| 238 | * Uses MD5 hashs.  | 
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| 239 | *  | 
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| 240 | * @param string $clear The clear text to hash  | 
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| 241 | * @return string Hashed password  | 
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| 242 | */  | 
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| 243 |     public function hash_md5($clear) { | 
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| 246 | |||
| 247 | /**  | 
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| 248 | * Password hashing method 'sha1'  | 
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| 249 | *  | 
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| 250 | * Uses SHA1 hashs.  | 
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| 251 | *  | 
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| 252 | * @param string $clear The clear text to hash  | 
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| 253 | * @return string Hashed password  | 
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| 254 | */  | 
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| 255 |     public function hash_sha1($clear) { | 
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| 258 | |||
| 259 | /**  | 
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| 260 | * Password hashing method 'ssha' as used by LDAP  | 
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| 261 | *  | 
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| 262 | * Uses salted SHA1 hashs. Salt is 4 bytes long.  | 
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| 263 | *  | 
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| 264 | * @param string $clear The clear text to hash  | 
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| 265 | * @param string $salt The salt to use, null for random  | 
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| 266 | * @return string Hashed password  | 
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| 267 | */  | 
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| 268 |     public function hash_ssha($clear, $salt = null) { | 
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| 272 | |||
| 273 | /**  | 
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| 274 | * Password hashing method 'crypt'  | 
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| 275 | *  | 
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| 276 | * Uses salted crypt hashs. Salt is 2 bytes long.  | 
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| 277 | *  | 
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| 278 | * @param string $clear The clear text to hash  | 
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| 279 | * @param string $salt The salt to use, null for random  | 
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| 280 | * @return string Hashed password  | 
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| 281 | */  | 
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| 282 |     public function hash_crypt($clear, $salt = null) { | 
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| 286 | |||
| 287 | /**  | 
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| 288 | * Password hashing method 'mysql'  | 
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| 289 | *  | 
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| 290 | * This method was used by old MySQL systems  | 
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| 291 | *  | 
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| 292 | * @link http://php.net/mysql  | 
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| 293 | * @author <soren at byu dot edu>  | 
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| 294 | * @param string $clear The clear text to hash  | 
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| 295 | * @return string Hashed password  | 
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| 296 | */  | 
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| 297 |     public function hash_mysql($clear) { | 
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| 311 | |||
| 312 | /**  | 
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| 313 | * Password hashing method 'my411'  | 
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| 314 | *  | 
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| 315 | * Uses SHA1 hashs. This method is used by MySQL 4.11 and above  | 
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| 316 | *  | 
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| 317 | * @param string $clear The clear text to hash  | 
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| 318 | * @return string Hashed password  | 
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| 319 | */  | 
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| 320 |     public function hash_my411($clear) { | 
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| 323 | |||
| 324 | /**  | 
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| 325 | * Password hashing method 'kmd5'  | 
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| 326 | *  | 
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| 327 | * Uses salted MD5 hashs.  | 
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| 328 | *  | 
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| 329 | * Salt is 2 bytes long, but stored at position 16, so you need to pass at  | 
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| 330 | * least 18 bytes. You can pass the crypted hash as salt.  | 
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| 331 | *  | 
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| 332 | * @param string $clear The clear text to hash  | 
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| 333 | * @param string $salt The salt to use, null for random  | 
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| 334 | * @return string Hashed password  | 
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| 335 | */  | 
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| 336 |     public function hash_kmd5($clear, $salt = null) { | 
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| 344 | |||
| 345 | /**  | 
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| 346 | * Password hashing method 'pmd5'  | 
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| 347 | *  | 
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| 348 | * Uses salted MD5 hashs. Salt is 1+8 bytes long, 1st byte is the  | 
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| 349 | * iteration count when given, for null salts $compute is used.  | 
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| 350 | *  | 
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| 351 | * The actual iteration count is the given count squared, maximum is  | 
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| 352 | * 30 (-> 1073741824). If a higher one is given, the function throws  | 
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| 353 | * an exception.  | 
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| 354 | *  | 
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| 355 | * @link http://www.openwall.com/phpass/  | 
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| 356 | *  | 
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| 357 | * @param string $clear The clear text to hash  | 
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| 358 | * @param string $salt The salt to use, null for random  | 
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| 359 | * @param string $magic The hash identifier (P or H)  | 
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| 360 | * @param int $compute The iteration count for new passwords  | 
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| 361 | * @throws \Exception  | 
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| 362 | * @return string Hashed password  | 
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| 363 | */  | 
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| 364 |     public function hash_pmd5($clear, $salt = null, $magic = 'P', $compute = 8) { | 
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| 409 | |||
| 410 | /**  | 
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| 411 | * Alias for hash_pmd5  | 
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| 412 | *  | 
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| 413 | * @param string $clear  | 
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| 414 | * @param null|string $salt  | 
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| 415 | * @param string $magic  | 
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| 416 | * @param int $compute  | 
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| 417 | *  | 
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| 418 | * @return string  | 
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| 419 | * @throws \Exception  | 
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| 420 | */  | 
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| 421 |     public function hash_hmd5($clear, $salt = null, $magic = 'H', $compute = 8) { | 
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| 424 | |||
| 425 | /**  | 
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| 426 | * Password hashing method 'djangosha1'  | 
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| 427 | *  | 
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| 428 | * Uses salted SHA1 hashs. Salt is 5 bytes long.  | 
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| 429 | * This is used by the Django Python framework  | 
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| 430 | *  | 
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| 431 | * @link http://docs.djangoproject.com/en/dev/topics/auth/#passwords  | 
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| 432 | *  | 
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| 433 | * @param string $clear The clear text to hash  | 
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| 434 | * @param string $salt The salt to use, null for random  | 
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| 435 | * @return string Hashed password  | 
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| 436 | */  | 
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| 437 |     public function hash_djangosha1($clear, $salt = null) { | 
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| 441 | |||
| 442 | /**  | 
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| 443 | * Password hashing method 'djangomd5'  | 
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| 444 | *  | 
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| 445 | * Uses salted MD5 hashs. Salt is 5 bytes long.  | 
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| 446 | * This is used by the Django Python framework  | 
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| 447 | *  | 
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| 448 | * @link http://docs.djangoproject.com/en/dev/topics/auth/#passwords  | 
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| 449 | *  | 
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| 450 | * @param string $clear The clear text to hash  | 
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| 451 | * @param string $salt The salt to use, null for random  | 
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| 452 | * @return string Hashed password  | 
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| 453 | */  | 
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| 454 |     public function hash_djangomd5($clear, $salt = null) { | 
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| 458 | |||
| 459 | /**  | 
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| 460 | * Password hashing method 'djangopbkdf2'  | 
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| 461 | *  | 
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| 462 | * An algorithm and iteration count should be given in the opts array.  | 
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| 463 | * Defaults to sha256 and 24000 iterations  | 
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| 464 | *  | 
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| 465 | * @param string $clear The clear text to hash  | 
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| 466 | * @param string $salt The salt to use, null for random  | 
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| 467 |      * @param array $opts ('algo' => hash algorithm, 'iter' => iterations) | 
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| 468 | * @return string Hashed password  | 
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| 469 | * @throws \Exception when PHP is missing support for the method/algo  | 
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| 470 | */  | 
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| 471 |     public function hash_djangopbkdf2($clear, $salt=null, $opts=array()) { | 
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| 493 | |||
| 494 | /**  | 
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| 495 | * Alias for djangopbkdf2 defaulting to sha256 as hash algorithm  | 
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| 496 | *  | 
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| 497 | * @param string $clear The clear text to hash  | 
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| 498 | * @param string $salt The salt to use, null for random  | 
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| 499 |      * @param array $opts ('iter' => iterations) | 
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| 500 | * @return string Hashed password  | 
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| 501 | * @throws \Exception when PHP is missing support for the method/algo  | 
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| 502 | */  | 
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| 503 |     public function hash_djangopbkdf2_sha256($clear, $salt=null, $opts=array()) { | 
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| 507 | |||
| 508 | /**  | 
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| 509 | * Alias for djangopbkdf2 defaulting to sha1 as hash algorithm  | 
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| 510 | *  | 
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| 511 | * @param string $clear The clear text to hash  | 
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| 512 | * @param string $salt The salt to use, null for random  | 
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| 513 |      * @param array $opts ('iter' => iterations) | 
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| 514 | * @return string Hashed password  | 
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| 515 | * @throws \Exception when PHP is missing support for the method/algo  | 
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| 516 | */  | 
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| 517 |     public function hash_djangopbkdf2_sha1($clear, $salt=null, $opts=array()) { | 
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| 521 | |||
| 522 | /**  | 
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| 523 | * Passwordhashing method 'bcrypt'  | 
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| 524 | *  | 
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| 525 | * Uses a modified blowfish algorithm called eksblowfish  | 
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| 526 | * This method works on PHP 5.3+ only and will throw an exception  | 
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| 527 | * if the needed crypt support isn't available  | 
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| 528 | *  | 
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| 529 | * A full hash should be given as salt (starting with $a2$) or this  | 
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| 530 | * will break. When no salt is given, the iteration count can be set  | 
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| 531 | * through the $compute variable.  | 
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| 532 | *  | 
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| 533 | * @param string $clear The clear text to hash  | 
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| 534 | * @param string $salt The salt to use, null for random  | 
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| 535 | * @param int $compute The iteration count (between 4 and 31)  | 
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| 536 | * @throws \Exception  | 
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| 537 | * @return string Hashed password  | 
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| 538 | */  | 
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| 539 |     public function hash_bcrypt($clear, $salt = null, $compute = 10) { | 
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| 552 | |||
| 553 | /**  | 
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| 554 | * Password hashing method SHA512  | 
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| 555 | *  | 
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| 556 | * This is only supported on PHP 5.3.2 or higher and will throw an exception if  | 
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| 557 | * the needed crypt support is not available  | 
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| 558 | *  | 
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| 559 | * @param string $clear The clear text to hash  | 
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| 560 | * @param string $salt The salt to use, null for random  | 
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| 561 | * @param string $magic The rounds for sha512 (for example "rounds=3000"), null for default value  | 
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| 562 | * @return string Hashed password  | 
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| 563 | * @throws \Exception  | 
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| 564 | */  | 
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| 565 |     public function hash_sha512($clear, $salt = null, $magic = null) { | 
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| 576 | |||
| 577 | /**  | 
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| 578 | * Password hashing method 'mediawiki'  | 
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| 579 | *  | 
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| 580 | * Uses salted MD5, this is referred to as Method B in MediaWiki docs. Unsalted md5  | 
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| 581 | * method 'A' is not supported.  | 
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| 582 | *  | 
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| 583 | * @link http://www.mediawiki.org/wiki/Manual_talk:User_table#user_password_column  | 
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| 584 | *  | 
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| 585 | * @param string $clear The clear text to hash  | 
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| 586 | * @param string $salt The salt to use, null for random  | 
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| 587 | * @return string Hashed password  | 
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| 588 | */  | 
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| 589 |     public function hash_mediawiki($clear, $salt = null) { | 
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| 593 | |||
| 594 | /**  | 
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| 595 | * Wraps around native hash_hmac() or reimplents it  | 
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| 596 | *  | 
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| 597 | * This is not directly used as password hashing method, and thus isn't callable via the  | 
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| 598 | * verify_hash() method. It should be used to create signatures and might be used in other  | 
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| 599 | * password hashing methods.  | 
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| 600 | *  | 
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| 601 | * @see hash_hmac()  | 
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| 602 | * @author KC Cloyd  | 
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| 603 | * @link http://php.net/manual/en/function.hash-hmac.php#93440  | 
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| 604 | *  | 
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| 605 | * @param string $algo Name of selected hashing algorithm (i.e. "md5", "sha256", "haval160,4",  | 
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| 606 | * etc..) See hash_algos() for a list of supported algorithms.  | 
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| 607 | * @param string $data Message to be hashed.  | 
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| 608 | * @param string $key Shared secret key used for generating the HMAC variant of the message digest.  | 
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| 609 | * @param bool $raw_output When set to TRUE, outputs raw binary data. FALSE outputs lowercase hexits.  | 
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| 610 | * @return string  | 
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| 611 | */  | 
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| 612 |     public static function hmac($algo, $data, $key, $raw_output = false) { | 
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| 639 | |||
| 640 | /**  | 
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| 641 | * Use a secure random generator  | 
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| 642 | *  | 
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| 643 | * @param int $min  | 
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| 644 | * @param int $max  | 
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| 645 | * @return int  | 
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| 646 | */  | 
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| 647 |     protected function random($min, $max){ | 
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| 656 | }  | 
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| 657 | 
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVarassignment in line 1 and the$higherassignment in line 2 are dead. The first because$myVaris never used and the second because$higheris always overwritten for every possible time line.