Php symmetric encryption algorithm example _ PHP Tutorial

Example of a php symmetric encryption algorithm. The php symmetric encryption algorithm KEY is a previously defined constant copy code. the code is as follows: Mcrypt: encrypt (); Mcrypt: decrypt (); the copy code is as follows: defined (ROOT) orexit (AccessDenie php symmetric encryption algorithm

KEY is a previously defined constant.

The code is as follows:

Mcrypt: encrypt ();
Mcrypt: decrypt ();

The code is as follows:

Defined ('root') or exit ('Access Denied ');

Class Mcrypt {

Public static function encrypt ($ code ){
Return base64_encode (mcrypt_encrypt (encrypt, md5 (KEY), $ code, MCRYPT_MODE_ECB, mcrypt_create_iv (Encrypt (encrypt, MCRYPT_MODE_ECB), MCRYPT_RAND )));
}

Public static function decrypt ($ code ){
Return mcrypt_decrypt (encrypt, md5 (KEY), base64_decode ($ code), MCRYPT_MODE_ECB, mcrypt_create_iv (Encrypt (encrypt, MCRYPT_MODE_ECB), MCRYPT_RAND ));
}

}

Common symmetric encryption algorithms (DES/AES)

Xcrypt. php

The code is as follows:

/**
* Common symmetric encryption algorithms
* Supported keys: 64/128/256 bit (byte length: 8/16/32)
* Supported algorithms: DES/AES (auto match based on key length: DES: 64bit AES: 128/256 bit)
* Supported mode: CBC/ECB/OFB/CFB
* Ciphertext encoding: base64 string/hexadecimal string/binary string stream
* Filling method: PKCS5Padding (DES)
*
* @ Author: linvo
* @ Version: 1.0.0
* @ Date: 2013/1/10
*/
Class Xcrypt {

Private $ mcrypt;
Private $ key;
Private $ mode;
Private $ iv;
Private $ blocksize;

/**
* Constructor
*
* @ Param string key
* @ Param string mode
* @ Param string vector ("off": not used/"auto": Automatic/Others: Specified value, same length as the key)
*/
Public function _ construct ($ key, $ mode = 'cbc', $ iv = "off "){
Switch (strlen ($ key )){
Case 8:
$ This-> mcrypt = MCRYPT_DES;
Break;
Case 16:
$ This-> mcrypt = MCRYPT_RIJNDAEL_128;
Break;
Case 32:
$ This-> mcrypt = MCRYPT_RIJNDAEL_256;
Break;
Default:
Die ("Key size must be 8/16/32 ");
}

$ This-> key = $ key;

Switch (strtolower ($ mode )){
Case 'ofb ':
$ This-> mode = MCRYPT_MODE_OFB;
If ($ iv = 'off') die ('ofb must give a IV'); // OFB must have a vector
Break;
Case 'cfb ':
$ This-> mode = MCRYPT_MODE_CFB;
If ($ iv = 'off') die ('cfb must give a IV'); // CFB must have a vector
Break;
Case 'ECB ':
$ This-> mode = MCRYPT_MODE_ECB;
$ Iv = 'off'; // vector not required by ECB
Break;
Case 'cbc ':
Default:
$ This-> mode = MCRYPT_MODE_CBC;
}

Switch (strtolower ($ iv )){
Case "off ":
$ This-> iv = null;
Break;
Case "auto ":
$ Source = PHP_ OS = 'winnt '? MCRYPT_RAND: MCRYPT_DEV_RANDOM;
$ This-> iv = mcrypt_create_iv (mcrypt_get_block_size ($ this-> mcrypt, $ this-> mode), $ source );
Break;
Default:
$ This-> iv = $ iv;
}


}


/**
* Obtain vector value
* @ Param string vector value encoding (base64/hex/bin)
* @ Return string vector value
*/
Public function getIV ($ code = 'base64 '){
Switch ($ code ){
Case 'base64 ':
$ Ret = base64_encode ($ this-> iv );
Break;
Case 'Hex ':
$ Ret = bin2hex ($ this-> iv );
Break;
Case 'bin ':
Default:
$ Ret = $ this-> iv;
}
Return $ ret;
}


/**
* Encryption
* @ Param string plaintext
* @ Param string ciphertext encoding (base64/hex/bin)
* @ Return string ciphertext
*/
Public function encrypt ($ str, $ code = 'base64 '){
If ($ this-> mcrypt = MCRYPT_DES) $ str = $ this-> _ pkcs5Pad ($ str );

If (isset ($ this-> iv )){
$ Result = mcrypt_encrypt ($ this-> mcrypt, $ this-> key, $ str, $ this-> mode, $ this-> iv );
} Else {
@ $ Result = mcrypt_encrypt ($ this-> mcrypt, $ this-> key, $ str, $ this-> mode );
}

Switch ($ code ){
Case 'base64 ':
$ Ret = base64_encode ($ result );
Break;
Case 'Hex ':
$ Ret = bin2hex ($ result );
Break;
Case 'bin ':
Default:
$ Ret = $ result;
}

Return $ ret;

}

/**
* Decryption
* @ Param string ciphertext
* @ Param string ciphertext encoding (base64/hex/bin)
* @ Return string plaintext
*/
Public function decrypt ($ str, $ code = "base64 "){
$ Ret = false;

Switch ($ code ){
Case 'base64 ':
$ Str = base64_decode ($ str );
Break;
Case 'Hex ':
$ Str = $ this-> _ hex2bin ($ str );
Break;
Case 'bin ':
Default:
}

If ($ str! = False ){
If (isset ($ this-> iv )){
$ Ret = mcrypt_decrypt ($ this-> mcrypt, $ this-> key, $ str, $ this-> mode, $ this-> iv );
} Else {
@ $ Ret = mcrypt_decrypt ($ this-> mcrypt, $ this-> key, $ str, $ this-> mode );
}
If ($ this-> mcrypt = MCRYPT_DES) $ ret = $ this-> _ pkcs5Unpad ($ ret );
$ Ret = trim ($ ret );
}

Return $ ret;
}

Private function _ pkcs5Pad ($ text ){
$ This-> blocksize = mcrypt_get_block_size ($ this-> mcrypt, $ this-> mode );
$ Pad = $ this-> blocksize-(strlen ($ text) % $ this-> blocksize );
Return $ text. str_repeat (chr ($ pad), $ pad );
}

Private function _ pkcs5Unpad ($ text ){
$ Pad = ord ($ text {strlen ($ text)-1 });
If ($ pad> strlen ($ text) return false;
If (strspn ($ text, chr ($ pad), strlen ($ text)-$ pad )! = $ Pad) return false;
$ Ret = substr ($ text, 0,-1 * $ pad );
Return $ ret;
}

Private function _ hex2bin ($ hex = false ){
$ Ret = $ hex! = False & preg_match ('/^ [0-9a-fA-F] + $/I', $ hex )? Pack ("H *", $ hex): false;
Return $ ret;
}
}

Usage of the above class

The code is as follows:

Header ('content-Type: text/html; Charset = utf-8 ;');

Include "xcrypt. php ";

Echo'

';
$ A = isset ($ _ GET ['A'])? $ _ GET ['A']: 'Test 100 ';

// Key
$ Key = '000000'; // 12345678123456781234567812345678 bit
$ Key = '000000'; // 1234567812345678 bit
$ Key = '000000'; // 64 bit

// Set the mode and IV
$ M = new Xcrypt ($ key, 'cbc', 'auto ');

// Obtain the vector value
Echo 'vector :';
Var_dump ($ m-> getIV ());

// Encryption
$ B = $ m-> encrypt ($ a, 'base64 ');
// Decrypt
$ C = $ m-> decrypt ($ B, 'base64 ');

Echo 'encrypted :';
Var_dump ($ B );
Echo 'decrypted :';
Var_dump ($ c );
Echo'

';

The primary KEY is the defined constant code as follows: Mcrypt: encrypt (); Mcrypt: decrypt (); the code is as follows: defined ('root ') or exit ('Access Denie...