Complex classes like RSA 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 RSA, and based on these observations, apply Extract Interface, too.
| 1 | <?php | ||
| 17 | final class RSA | ||
| 18 | { | ||
| 19 | /** | ||
| 20 | * ASN1 Integer. | ||
| 21 | */ | ||
| 22 | const ASN1_INTEGER = 2; | ||
| 23 | |||
| 24 | /** | ||
| 25 | * ASN1 Bit String. | ||
| 26 | */ | ||
| 27 | const ASN1_BITSTRING = 3; | ||
| 28 | |||
| 29 | /** | ||
| 30 | * ASN1 Octet String. | ||
| 31 | */ | ||
| 32 | const ASN1_OCTETSTRING = 4; | ||
| 33 | |||
| 34 | /** | ||
| 35 | * ASN1 Object Identifier. | ||
| 36 | */ | ||
| 37 | const ASN1_OBJECT = 6; | ||
| 38 | |||
| 39 | /** | ||
| 40 | * ASN1 Sequence (with the constucted bit set). | ||
| 41 | */ | ||
| 42 | const ASN1_SEQUENCE = 48; | ||
| 43 | |||
| 44 | /** | ||
| 45 | * To use the pure-PHP implementation. | ||
| 46 | */ | ||
| 47 | const MODE_INTERNAL = 1; | ||
| 48 | |||
| 49 | /** | ||
| 50 | * To use the OpenSSL library. | ||
| 51 | */ | ||
| 52 | const MODE_OPENSSL = 2; | ||
| 53 | |||
| 54 | /** | ||
| 55 | * PKCS#1 formatted private key. | ||
| 56 | */ | ||
| 57 | const PRIVATE_FORMAT_PKCS1 = 0; | ||
| 58 | |||
| 59 | /** | ||
| 60 | * PuTTY formatted private key. | ||
| 61 | */ | ||
| 62 | const PRIVATE_FORMAT_PUTTY = 1; | ||
| 63 | |||
| 64 | /** | ||
| 65 | * XML formatted private key. | ||
| 66 | */ | ||
| 67 | const PRIVATE_FORMAT_XML = 2; | ||
| 68 | |||
| 69 | /** | ||
| 70 | * PKCS#8 formatted private key. | ||
| 71 | */ | ||
| 72 | const PRIVATE_FORMAT_PKCS8 = 8; | ||
| 73 | |||
| 74 | /** | ||
| 75 | * Raw public key. | ||
| 76 | */ | ||
| 77 | const PUBLIC_FORMAT_RAW = 3; | ||
| 78 | |||
| 79 | /** | ||
| 80 | * PKCS#1 formatted public key (raw). | ||
| 81 | */ | ||
| 82 | const PUBLIC_FORMAT_PKCS1 = 4; | ||
| 83 | |||
| 84 | /** | ||
| 85 | * Precomputed Zero. | ||
| 86 | * | ||
| 87 | * @var \Jose\Util\BigInteger | ||
| 88 | */ | ||
| 89 | private $zero; | ||
| 90 | |||
| 91 | /** | ||
| 92 | * Precomputed One. | ||
| 93 | * | ||
| 94 | * @var \Jose\Util\BigInteger | ||
| 95 | */ | ||
| 96 | private $one; | ||
| 97 | |||
| 98 | /** | ||
| 99 | * Modulus (ie. n). | ||
| 100 | * | ||
| 101 | * @var \Jose\Util\BigInteger | ||
| 102 | */ | ||
| 103 | private $modulus; | ||
| 104 | |||
| 105 | /** | ||
| 106 | * Modulus length. | ||
| 107 | * | ||
| 108 | * @var int | ||
| 109 | */ | ||
| 110 | private $k; | ||
| 111 | |||
| 112 | /** | ||
| 113 | * Exponent (ie. e or d). | ||
| 114 | * | ||
| 115 | * @var \Jose\Util\BigInteger | ||
| 116 | */ | ||
| 117 | private $exponent; | ||
| 118 | |||
| 119 | /** | ||
| 120 | * Primes for Chinese Remainder Theorem (ie. p and q). | ||
| 121 | * | ||
| 122 | * @var \Jose\Util\BigInteger[] | ||
| 123 | */ | ||
| 124 | private $primes; | ||
| 125 | |||
| 126 | /** | ||
| 127 | * Exponents for Chinese Remainder Theorem (ie. dP and dQ). | ||
| 128 | * | ||
| 129 | * @var \Jose\Util\BigInteger[] | ||
| 130 | */ | ||
| 131 | private $exponents; | ||
| 132 | |||
| 133 | /** | ||
| 134 | * Coefficients for Chinese Remainder Theorem (ie. qInv). | ||
| 135 | * | ||
| 136 | * @var \Jose\Util\BigInteger[] | ||
| 137 | */ | ||
| 138 | private $coefficients; | ||
| 139 | |||
| 140 | /** | ||
| 141 | * Hash function. | ||
| 142 | * | ||
| 143 | * @var \Jose\Util\Hash | ||
| 144 | */ | ||
| 145 | private $hash; | ||
| 146 | |||
| 147 | /** | ||
| 148 | * Length of salt. | ||
| 149 | * | ||
| 150 | * @var int | ||
| 151 | */ | ||
| 152 | private $sLen; | ||
| 153 | |||
| 154 | /** | ||
| 155 | * Hash function for the Mask Generation Function. | ||
| 156 | * | ||
| 157 | * @var \Jose\Util\Hash | ||
| 158 | */ | ||
| 159 | private $mgfHash; | ||
| 160 | |||
| 161 | /** | ||
| 162 | * Public Exponent. | ||
| 163 | * | ||
| 164 | * @var mixed | ||
| 165 | */ | ||
| 166 | private $publicExponent = false; | ||
| 167 | |||
| 168 | /** | ||
| 169 | * RSA constructor. | ||
| 170 | */ | ||
| 171 | public function __construct() | ||
| 179 | |||
| 180 | /** | ||
| 181 | * Loads a public or private key. | ||
| 182 | * | ||
| 183 | * @param \Jose\Object\JWKInterface $key | ||
| 184 | */ | ||
| 185 | public function loadKey(JWKInterface $key) | ||
| 216 | |||
| 217 | /** | ||
| 218 | * Determines which hashing function should be used. | ||
| 219 | * | ||
| 220 | * @param string $hash | ||
| 221 | */ | ||
| 222 | public function setHash($hash) | ||
| 226 | |||
| 227 | /** | ||
| 228 | * Determines which hashing function should be used for the mask generation function. | ||
| 229 | * | ||
| 230 | * @param string $hash | ||
| 231 | */ | ||
| 232 | public function setMGFHash($hash) | ||
| 236 | |||
| 237 | /** | ||
| 238 | * Determines the salt length. | ||
| 239 | * | ||
| 240 | * @param int $sLen | ||
| 241 | */ | ||
| 242 | public function setSaltLength($sLen) | ||
| 246 | |||
| 247 | /** | ||
| 248 | * Integer-to-Octet-String primitive. | ||
| 249 | * | ||
| 250 | * @param \Jose\Util\BigInteger $x | ||
| 251 | * @param int $xLen | ||
| 252 | * | ||
| 253 | * @return string | ||
| 254 | */ | ||
| 255 | private function _i2osp($x, $xLen) | ||
| 265 | |||
| 266 | /** | ||
| 267 | * Octet-String-to-Integer primitive. | ||
| 268 | * | ||
| 269 | * @param string $x | ||
| 270 | * | ||
| 271 | * @return \Jose\Util\BigInteger | ||
| 272 | */ | ||
| 273 | private function _os2ip($x) | ||
| 277 | |||
| 278 | /** | ||
| 279 | * Exponentiate with or without Chinese Remainder Theorem. | ||
| 280 | * | ||
| 281 | * @param \Jose\Util\BigInteger $x | ||
| 282 | * | ||
| 283 | * @return \Jose\Util\BigInteger | ||
| 284 | */ | ||
| 285 | private function _exponentiate($x) | ||
| 328 | |||
| 329 | /** | ||
| 330 | * Performs RSA Blinding. | ||
| 331 | * | ||
| 332 | * @param \Jose\Util\BigInteger $x | ||
| 333 | * @param \Jose\Util\BigInteger $r | ||
| 334 | * @param int $i | ||
| 335 | * | ||
| 336 | * @return \Jose\Util\BigInteger | ||
| 337 | */ | ||
| 338 | private function _blind($x, $r, $i) | ||
| 349 | |||
| 350 | /** | ||
| 351 | * Performs blinded RSA equality testing. | ||
| 352 | * | ||
| 353 | * @param string $x | ||
| 354 | * @param string $y | ||
| 355 | * | ||
| 356 | * @return bool | ||
| 357 | */ | ||
| 358 | private function _equals($x, $y) | ||
| 371 | |||
| 372 | /** | ||
| 373 | * RSAEP. | ||
| 374 | * | ||
| 375 | * @param \Jose\Util\BigInteger $m | ||
| 376 | * | ||
| 377 | * @return \Jose\Util\BigInteger | ||
| 378 | */ | ||
| 379 | private function _rsaep($m) | ||
| 388 | |||
| 389 | /** | ||
| 390 | * RSADP. | ||
| 391 | * | ||
| 392 | * @param \Jose\Util\BigInteger $c | ||
| 393 | * | ||
| 394 | * @return \Jose\Util\BigInteger | ||
| 395 | */ | ||
| 396 | private function _rsadp($c) | ||
| 405 | |||
| 406 | /** | ||
| 407 | * RSASP1. | ||
| 408 | * | ||
| 409 | * @param \Jose\Util\BigInteger $m | ||
| 410 | * | ||
| 411 | * @return \Jose\Util\BigInteger | ||
| 412 | */ | ||
| 413 | private function _rsasp1($m) | ||
| 422 | |||
| 423 | /** | ||
| 424 | * RSAVP1. | ||
| 425 | * | ||
| 426 | * @param \Jose\Util\BigInteger $s | ||
| 427 | * | ||
| 428 | * @return \Jose\Util\BigInteger | ||
| 429 | */ | ||
| 430 | private function _rsavp1($s) | ||
| 439 | |||
| 440 | /** | ||
| 441 | * MGF1. | ||
| 442 | * | ||
| 443 | * @param string $mgfSeed | ||
| 444 | * @param int $maskLen | ||
| 445 | * | ||
| 446 | * @return string | ||
| 447 | */ | ||
| 448 | private function _mgf1($mgfSeed, $maskLen) | ||
| 461 | |||
| 462 | /** | ||
| 463 | * RSAES-OAEP-ENCRYPT. | ||
| 464 | * | ||
| 465 | * @param string $m | ||
| 466 | * @param string $l | ||
| 467 | * | ||
| 468 | * @return string | ||
| 469 | */ | ||
| 470 | private function _rsaes_oaep_encrypt($m, $l = '') | ||
| 506 | |||
| 507 | /** | ||
| 508 | * RSAES-OAEP-DECRYPT. | ||
| 509 | * | ||
| 510 | * @param string $c | ||
| 511 | * @param string $l | ||
| 512 | * | ||
| 513 | * @return string | ||
| 514 | */ | ||
| 515 | private function _rsaes_oaep_decrypt($c, $l = '') | ||
| 563 | |||
| 564 | /** | ||
| 565 | * EMSA-PSS-ENCODE. | ||
| 566 | * | ||
| 567 | * @param string $m | ||
| 568 | * @param int $emBits | ||
| 569 | * | ||
| 570 | * @return bool | ||
| 571 | */ | ||
| 572 | private function _emsa_pss_encode($m, $emBits) | ||
| 598 | |||
| 599 | /** | ||
| 600 | * EMSA-PSS-VERIFY. | ||
| 601 | * | ||
| 602 | * @param string $m | ||
| 603 | * @param string $em | ||
| 604 | * @param int $emBits | ||
| 605 | * | ||
| 606 | * @return string | ||
| 607 | */ | ||
| 608 | private function _emsa_pss_verify($m, $em, $emBits) | ||
| 644 | |||
| 645 | /** | ||
| 646 | * RSASSA-PSS-SIGN. | ||
| 647 | * | ||
| 648 | * @param string $m | ||
| 649 | * | ||
| 650 | * @return string | ||
| 651 | */ | ||
| 652 | private function _rsassa_pss_sign($m) | ||
| 668 | |||
| 669 | /** | ||
| 670 | * RSASSA-PSS-VERIFY. | ||
| 671 | * | ||
| 672 | * @param string $m | ||
| 673 | * @param string $s | ||
| 674 | * | ||
| 675 | * @return string | ||
| 676 | */ | ||
| 677 | private function _rsassa_pss_verify($m, $s) | ||
| 706 | |||
| 707 | /** | ||
| 708 | * Encryption. | ||
| 709 | * | ||
| 710 | * Both self::ENCRYPTION_OAEP and self::ENCRYPTION_PKCS1 both place limits on how long $plaintext can be. | ||
| 711 | * If $plaintext exceeds those limits it will be broken up so that it does and the resultant ciphertext's will | ||
| 712 | * be concatenated together. | ||
| 713 | * | ||
| 714 | * @see self::decrypt() | ||
| 715 | * | ||
| 716 | * @param string $plaintext | ||
| 717 | * | ||
| 718 | * @return string | ||
| 719 | */ | ||
| 720 | public function encrypt($plaintext) | ||
| 735 | |||
| 736 | /** | ||
| 737 | * Decryption. | ||
| 738 | * | ||
| 739 | * @param string $ciphertext | ||
| 740 | * | ||
| 741 | * @return string | ||
| 742 | */ | ||
| 743 | public function decrypt($ciphertext) | ||
| 764 | |||
| 765 | /** | ||
| 766 | * Create a signature. | ||
| 767 | * | ||
| 768 | * @param string $message | ||
| 769 | * | ||
| 770 | * @return string | ||
| 771 | */ | ||
| 772 | public function sign($message) | ||
| 781 | |||
| 782 | /** | ||
| 783 | * Verifies a signature. | ||
| 784 | * | ||
| 785 | * @param string $message | ||
| 786 | * @param string $signature | ||
| 787 | * | ||
| 788 | * @return bool | ||
| 789 | */ | ||
| 790 | public function verify($message, $signature) | ||
| 798 | } | ||
| 799 |