Hướng dẫn decrypt php password

The best way to encrypt and decrypt passwords is to use a standard library in PHP because the method of properly encrypting and decrypting passwords from scratch is complex and involves multiple possibilities of security vulnerabilities. Using the standard library ensures that the hashing implementation is verified and trusted.

Nội dung chính

  • What is password encryption in PHP?
  • Can we decrypt MD5 in PHP?
  • What is the best password encryption algorithm in PHP?
  • Can you decrypt hash password?

Note: This uses the PHP Password API available in version 5.5.0 and above.

Encryption of the password: To generate a hash from the string, we use the password_hash() function.

Syntax:

string password_hash(string $password, 
          mixed $algo, [array $options])

The password_hash() function creates a new password hash of the string using one of the available hashing algorithm. It returns the hash that is currently 60 character long, however, as new and stronger algorithms will be added to PHP, the length of the hash may increase. It is therefore recommended to allocate 255 characters for the column that may be used to store the hash in database.

The following algorithms are currently supported when using this function:

  • PASSWORD_DEFAULT
  • PASSWORD_BCRYPT
  • PASSWORD_ARGON2I
  • PASSWORD_ARGON2ID

Additional options can be passed to this function can be used to set the cost of encryption, the salt to be used during hashing, etc in the $options array.

The below example shows the method of using the password_hash() method:

Example:

php

  $plaintext_password = "[email protected]";

  $hash = password_hash($plaintext_password

          PASSWORD_DEFAULT);

  echo "Generated hash: ".$hash;

?>

Output:

Generated hash: $2y$10$7rLSvRVyTQORapkDOqmkhetjF6H9lJHngr4hJMSM2lHObJbW5EQh6

Decryption of the password: To decrypt a password hash and retrieve the original string, we use the password_verify() function.

Syntax:

bool password_verify(string $password, string $hash)

The password_verify() function verifies that the given hash matches the given password, generated by the password_hash() function. It returns true if the password and hash match, or false otherwise.

php

  $plaintext_password = "[email protected]";

  $hash

"$2y$10$8sA2N5Sx/1zMQv2yrTDAaOFlbGWECrrgB68axL.hBb78NhQdyAqWm";

  $verify = password_verify($plaintext_password, $hash);

  if ($verify) {

      echo 'Password Verified!';

  } else {

      echo 'Incorrect Password!';

  }

?>

Output:

Password Verified!

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.


Security Warning: This class is not secure. It's using Rijndael256-ECB, which is not semantically secure. Just because "it works" doesn't mean "it's secure". Also, it strips tailing spaces afterwards due to not using proper padding.

Found this class recently, it works like a dream!

class Encryption {
    var $skey = "yourSecretKey"; // you can change it

    public  function safe_b64encode($string) {
        $data = base64_encode($string);
        $data = str_replace(array('+','/','='),array('-','_',''),$data);
        return $data;
    }

    public function safe_b64decode($string) {
        $data = str_replace(array('-','_'),array('+','/'),$string);
        $mod4 = strlen($data) % 4;
        if ($mod4) {
            $data .= substr('====', $mod4);
        }
        return base64_decode($data);
    }

    public  function encode($value){ 
        if(!$value){return false;}
        $text = $value;
        $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
        $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
        $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $this->skey, $text, MCRYPT_MODE_ECB, $iv);
        return trim($this->safe_b64encode($crypttext)); 
    }

    public function decode($value){
        if(!$value){return false;}
        $crypttext = $this->safe_b64decode($value); 
        $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
        $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
        $decrypttext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $this->skey, $crypttext, MCRYPT_MODE_ECB, $iv);
        return trim($decrypttext);
    }
}

And to call it:

$str = "My secret String";

$converter = new Encryption;
$encoded = $converter->encode($str );
$decoded = $converter->decode($encoded);    

echo "$encoded

$decoded";

What is password encryption in PHP?

PHP encryption is important to the privacy and safety of your data. In practical terms, PHP encryption uses algorithms (sometimes called hashing algorithms) to translate the “clear” data into encrypted text that requires very specific decryption processes to “decode” the data back to the clean version.

Can we decrypt MD5 in PHP?

How to Decrypt MD5 Passwords in PHP? The MD5 cryptographic algorithm is not reversible i.e. We cannot decrypt a hash value created by the MD5 to get the input back to its original value. So there is no way to decrypt an MD5 password.

What is the best password encryption algorithm in PHP?

The writer recommends both sha256 and sha512. Only cryptographic hash functions may be used to implement password hashing. Hash functions like SHA256, SHA512, RipeMD, and WHIRLPOOL are cryptographic hash functions.

Can you decrypt hash password?

As commenters have mentioned, you cannot decrypt a hash. Hashing and encryption/decryption are two separate operations. Encryption and decryption are opposites, while hashing has no opposite function.