


Analysis of the specific usage of PHP encryption and decryption function authcode_PHP tutorial
The specific example code of PHP encryption and decryption function authcode is as follows:
- // Parameter explanation
- // $string: plaintext or ciphertext
- // $operation: DECODE means decryption, others means encryption
- // $key: Key
- // $expiry: Ciphertext validity period
-
function authcode($string, $operation =
'DECODE', $key = '', $expiry = 0) { - // Dynamic key length, the same plaintext will generate different ciphertext, relying on the dynamic key
- $ckey_length = 4;
- // Key
- $key = md5($key ? $key : $GLOBALS['discuz_auth_key']);
- // Key a will participate in encryption and decryption
- $ keya = md5(substr($key, 0, 16));
- // key b Will be used for data integrity verification
- $keyb = md5(substr ($key, 16, 16));
- // Key c is used to change the generated ciphertext
-
$ keyc = $ckey_length ? ($operation == 'DECODE'
? substr($string, 0, $ckey_length): substr (md5
(microtime()), -$ckey_length)) : ''; - //The key used by the PHP encryption and decryption function authcode to participate in the operation
- $cryptkey = $keya.md5($keya.$keyc);
- $key_length = strlen($cryptkey);
- // Plain text, the first 10 bits are used to save Timestamp, verify data validity when decrypting.
10 to 26 bits are used to save $keyb (key b). Data integrity will be verified through this key during decryption. - // If it is decoding, it will start from the $ckey_length bit, because the $ckey_
length bit before the ciphertext saves the dynamic key to ensure correct decryption -
$string = $operation == 'DECODE' ? base64_decode(substr
($string, $ckey_length)) : sprintf( '%010d', $expiry ?
$expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string; - $string_length = strlen($string);
- $result = ''; (0, 255); 🎜>();
- //PHP encryption and decryption function authcode generates key book for($i =
- 0; $i = 255; $i++) { $rndkey[$i] = ord($cryptkey[$i % $key_length]);
- }
- //Using a fixed algorithm to scramble the key book and increase randomness seems very complicated. In fact, it will not increase the strength of the ciphertext for( $j = $i
- = 0
- ; $i
-
256 ; $i++) { - $j = ($j + $box[$i] + $rndkey[$i]) % 256; $tmp = $box[$i]; $box[$i] = $box[$j]; $box [$j] = $tmp;
- } //PHP encryption and decryption function authcode core encryption and decryption part
- for($a = $
- j = $
- i =
- 0 ; $i
- $string_length; $i++) {
- $a = ($a + 1) % 256; $j = ($j + $box[$a]) % 256; $tmp = $box[$a] ;
- $box[$a] = $box[$j]; $box[$j] = $tmp;
- // PHP encryption and decryption function authcode gets the key from the key book, performs XOR, and then converts it into characters $result
- .= chr (ord($string[$i]) ^ (
- $box[($box[$a] + $box[$j]) % 256]));
- }
- if($operation
- == 'DECODE') { // substr($result, 0, 10) == 0 Verify data validity // substr($result, 0, 10) - time()
> 0 Verify data validity - // substr($result, 10, 16) == substr(md5(substr
- ($result, 26).$keyb), 0, 16) Verify data integrity // Verify data validity, please see the format of unencrypted plaintext
- if((substr($result, 0, 10) == 0 || substr( $result, 0, 10) - time() >
- 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
- return substr($result, 26);
- } else {
- return '';
- }
- } else {
-
//PHP encryption and decryption function authcode saves the dynamic key in the ciphertext, which is why the same plaintext can be decrypted after
producing different ciphertexts - // Because the encrypted ciphertext may contain some special characters,
may be lost during the copying process, so base64 encoding is used - return $ keyc.str_replace('=', '',
base64_encode($result)); - }
- }
The above code is the specific usage of PHP encryption and decryption function authcode. I hope you can initially grasp the meaning of this function through the content introduced in this article.

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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