PHP 3DES encryption decryption class program code

3DES (or Triple DES) is the generic term for a triple-Data encryption Algorithm (Tdea,triple-Encryption-algorithm) block cipher. It is equivalent to applying three DES encryption algorithms to each block of data. The encryption key length of the original des Cipher becomes easily brute force because of the enhancement of computer computing power; 3DES is designed to provide a relatively simple way to avoid similar attacks by increasing the length of the Des's key, rather than designing a new block cipher algorithm.

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<?php Class Crypt3des { var $key; function Crypt3des ($key) { $this->key = $key; } Function Encrypt ($input) { $size = mcrypt_get_block_size (mcrypt_3des, ' ECB '); $input = $this->pkcs5_pad ($ input, $size); $key = Str_pad ($this->key,24, ' 0 '); $td = Mcrypt_module_open (Mcrypt_3des, ', ' ECB ', '); $iv = @mcrypt_create_iv (Mcrypt_enc_get_iv_size ($TD), Mcrypt_rand); @mcrypt_generic_init ($TD, $key, $IV); $data = Mcrypt_generic ($TD, $input); Mcrypt_generic_deinit ($TD); Mcrypt_module_close ($TD); //$data = Base64_encode ($this->paddingpkcs7 ($data)); $data = Base64_encode ($data); return $data; } function Decrypt ($encrypted) { $encrypted = Base64_decode ($encrypted); $key = Str_pad ($this->key,24, ' 0 '); $TD = Mcrypt_module_open (Mcrypt_3des, ', ' ECB ', '); $iv = @mcrypt_create_iv (Mcrypt_enc_get_iv_size ($TD), Mcrypt_rand); $ks = Mcrypt_enc_get_key_size ($TD); @mcrypt_generic_init ($TD, $key, $IV); $decrypted = Mdecrypt_generic ($TD, $encrypted); Mcrypt_generic_deinit ($TD); Mcrypt_module_close ($TD); $y = $this->pkcs5_unpad ($decrypted); return $y; } function Pkcs5_pad ($text, $blocksize) { $pad = $blocksize-(strlen ($text)% $blocksize); Return $text. Str_repeat (Chr ($pad), $pad); } function Pkcs5_unpad ($text) { $pad = Ord ($text {strlen ($text)-1}); if ($pad > strlen ($text)) { return false; } if (strspn ($text, Chr ($pad), strlen ($text)-$pad)!= $pad) { return false; } Return substr ($text, 0,-1 * $pad); } function PaddingPKCS7 ($data) { $block _size = mcrypt_get_block_size (Mcrypt_3des, MCRYPT_MODE_CBC); $padding _char = $block _size-(strlen ($data)% $block _size); $data. = Str_repeat (Chr ($padding _char), $padding _char); return $data; } } Usage: $crypt = new Crypt3des (' key '); $a = ' to encrypt string '; $code = $crypt->encrypt ($a);//encryption echo $crypt->decrypt ($code);//Decrypt