Passport decryption functions written by PHP

/** * Passport decryption function * * @param string of strings after encryption * @param string private key (for decryption and encryption) * * Results of @return string strings being decrypted by private key */ function Passport_decrypt ($txt, $key) { The result of the $txt is that the encrypted string is Base64 decoded and then, together with the private key, return value after processing by the Passport_key () function $txt = Passport_key (Base64_decode ($txt), $key); Variable initialization $tmp = "; For loop, $i starting from 0 to an integer less than $txt string length for ($i = 0; $i < strlen ($txt); $i + +) { $tmp string adds a bit to the end of the $txt $i bit, With $txt $i + 1-bit XOR. Then $i = $i + 1 $tmp. = $txt [$i] ^ $txt [+ + $i]; } Returns the value of the $tmp as a result return $tmp; } /** * Passport Key processing function * * @param string to be encrypted or to be decrypted * @param string private key (for decryption and encryption) * * @return The key after string processing */ function Passport_key ($txt, $encrypt _key) { Assigns $encrypt _key to $encrypt _key by MD5 () $encrypt _key = MD5 ($encrypt _key); Variable initialization $ctr = 0; $tmp = "; For loop, $i starting from 0 to an integer less than $txt string length for ($i = 0; $i < strlen ($txt); $i + +) { $ctr zeroed If $ctr = $encrypt the length of the _key $ctr = $ctr = = strlen ($encrypt _key)? 0: $ctr; $tmp string adds a bit to the end of the $txt $i bit, With $encrypt _key $ctr + 1-bit XOR. Then $ctr = $ctr + 1 $tmp. = $txt [$i] ^ $encrypt _key[$ctr + +]; } Returns the value of the $tmp as a result return $tmp; } ?> Copy Code

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