79 lines
1.8 KiB
PHP
79 lines
1.8 KiB
PHP
<?php
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namespace FluentForm\App\Helpers;
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class Protector
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{
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/**
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* Get the salt for the encryption and decryption.
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*/
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public static function getSalt()
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{
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$salt = get_option('_fluentform_security_salt');
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if (!$salt) {
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$salt = wp_generate_password();
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update_option('_fluentform_security_salt', $salt, 'no');
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}
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return $salt;
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}
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/**
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* Encryp a text using a predefined salt.
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*
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* @param string $text
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*
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* @return string $text
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*/
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public static function encrypt($text)
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{
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$key = static::getSalt();
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$cipher = 'AES-128-CBC';
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$ivlen = openssl_cipher_iv_length($cipher);
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$iv = openssl_random_pseudo_bytes($ivlen);
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$ciphertext_raw = openssl_encrypt($text, $cipher, $key, $options = OPENSSL_RAW_DATA, $iv);
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$hmac = hash_hmac('sha256', $ciphertext_raw, $key, $as_binary = true);
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return base64_encode($iv . $hmac . $ciphertext_raw);
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}
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/**
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* Decrypt a text using a predefined salt.
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*
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* @param string $text
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*
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* @return string $text
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*/
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public static function decrypt($text)
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{
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$key = static::getSalt();
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$c = base64_decode($text);
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$cipher = 'AES-128-CBC';
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$ivlen = openssl_cipher_iv_length($cipher);
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$iv = substr($c, 0, $ivlen);
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$hmac = substr($c, $ivlen, $sha2len = 32);
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$ciphertext_raw = substr($c, $ivlen + $sha2len);
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$original_plaintext = openssl_decrypt($ciphertext_raw, $cipher, $key, $options = OPENSSL_RAW_DATA, $iv);
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$calcmac = hash_hmac('sha256', $ciphertext_raw, $key, $as_binary = true);
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if (hash_equals($hmac, $calcmac)) { // timing attack safe comparison
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return $original_plaintext;
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}
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}
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}
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