73 lines
1.6 KiB
PHP
Executable file
73 lines
1.6 KiB
PHP
Executable file
<?php
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define('ID_OBFUSCATION_SALT_FILE', __DIR__.'/idObfuscation_salt.php');
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/**
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* @return string|int
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*/
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function getObfuscationSalt()
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{
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if (!file_exists(ID_OBFUSCATION_SALT_FILE)) {
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$bytes = openssl_random_pseudo_bytes(4);
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$saltData = "<?php\n\n\$OBFUSCATION_SALT = 0x".bin2hex($bytes).";\n";
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file_put_contents(ID_OBFUSCATION_SALT_FILE, $saltData);
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}
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if (
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file_exists(ID_OBFUSCATION_SALT_FILE)
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&& is_readable(ID_OBFUSCATION_SALT_FILE)
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) {
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require ID_OBFUSCATION_SALT_FILE;
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}
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return isset($OBFUSCATION_SALT) ? $OBFUSCATION_SALT : 0;
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}
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/**
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* This is a simple reversible hash function I made for encoding and decoding test IDs.
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* It is not cryptographically secure, don't use it to hash passwords or something!
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*
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* @param int|string $id
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* @param bool $dec
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*
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* @return int|string
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*/
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function obfdeobf($id, $dec)
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{
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$salt = getObfuscationSalt() & 0xFFFFFFFF;
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$id &= 0xFFFFFFFF;
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if ($dec) {
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$id ^= $salt;
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$id = (($id & 0xAAAAAAAA) >> 1) | ($id & 0x55555555) << 1;
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$id = (($id & 0x0000FFFF) << 16) | (($id & 0xFFFF0000) >> 16);
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return $id;
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}
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$id = (($id & 0x0000FFFF) << 16) | (($id & 0xFFFF0000) >> 16);
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$id = (($id & 0xAAAAAAAA) >> 1) | ($id & 0x55555555) << 1;
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return $id ^ $salt;
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}
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/**
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* @param int $id
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*
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* @return string
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*/
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function obfuscateId($id)
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{
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return str_pad(base_convert(obfdeobf($id + 1, false), 10, 36), 7, 0, STR_PAD_LEFT);
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}
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/**
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* @param string $id
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*
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* @return int
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*/
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function deobfuscateId($id)
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{
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return obfdeobf(base_convert($id, 36, 10), true) - 1;
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}
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