[PHP] Six Practical Encryption and Decryption Methods

First

 <? php   function encryptDecrypt($key, $string, $decrypt){    if($decrypt){    $decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "12");    return $decrypted;    }else{    $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key))));    return $encrypted;    }    }    // encryption :"z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk="   Echo encryptDecrypt ('password ','Hello weba Welcome', 0); // decrypt : "Hello weba welcomes you" echo encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=',1);   ?>

Second

 <? php   //Cryptographic function function lock_url($txt,$key='liiu'){   $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";   $nh = rand(0,64);   $ch = $chars[$nh];   $mdKey = md5($key.$ch);   $mdKey = substr($mdKey,$nh%8, $nh%8+7);   $txt = base64_encode($txt);   $tmp = '';   $i=0;$ j=0;$k = 0;   for ($i=0; $ i<strlen($txt); $ i++) {   $k = $k == strlen($mdKey) ?  0 : $k;   $j = ($nh+strpos($chars,$txt[$i])+ord($mdKey[$k++]))%64;   $tmp .= $ chars[$j];   }   return urlencode($ch.$tmp);   }   // decrypt Function function unlock_url($txt,$key='liiu'){   $txt = urldecode($txt);   $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";   $ch = $txt[0];   $nh = strpos($chars,$ch);   $mdKey = md5($key.$ch);   $mdKey = substr($mdKey,$nh%8, $nh%8+7);   $txt = substr($txt,1);   $tmp = '';   $i=0;$ j=0; $k = 0;   for ($i=0; $ i<strlen($txt); $ i++) {   $k = $k == strlen($mdKey) ?  0 : $k;   $j = strpos($chars,$txt[$i])-$nh - ord($mdKey[$k++]);   while ($j<0) $j+=64;   $tmp .= $ chars[$j];   }   return base64_decode($tmp);   }   ?>

Third

 <? php   //Improved algorithm //Cryptographic function function lock_url($txt,$key='str'){   $txt = $txt.$ key;   $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";   $nh = rand(0,64);   $ch = $chars[$nh];   $mdKey = md5($key.$ch);   $mdKey = substr($mdKey,$nh%8, $nh%8+7);   $txt = base64_encode($txt);   $tmp = '';   $i=0;$ j=0;$k = 0;   for ($i=0; $ i<strlen($txt); $ i++) {   $k = $k == strlen($mdKey) ?  0 : $k;   $j = ($nh+strpos($chars,$txt[$i])+ord($mdKey[$k++]))%64;   $tmp .= $ chars[$j];   }   return urlencode(base64_encode($ch.$tmp));   }   // decrypt Function function unlock_url($txt,$key='str'){   $txt = base64_decode(urldecode($txt));   $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";   $ch = $txt[0];   $nh = strpos($chars,$ch);   $mdKey = md5($key.$ch);   $mdKey = substr($mdKey,$nh%8, $nh%8+7);   $txt = substr($txt,1);   $tmp = '';   $i=0;$ j=0; $k = 0;   for ($i=0; $ i<strlen($txt); $ i++) {   $k = $k == strlen($mdKey) ?  0 : $k;   $j = strpos($chars,$txt[$i])-$nh - ord($mdKey[$k++]);   while ($j<0) $j+=64;   $tmp .= $ chars[$j];   }   return trim(base64_decode($tmp),$key);   }   ?>

Fourth

 <? php   function passport_encrypt($txt, $key = 'liiu') {    srand((double)microtime() * 1000000);    $encrypt_key = md5(rand(0, 32000));    $ctr = 0;    $tmp = '';    for($i = 0;$ i < strlen($txt); $ i++) {    $ctr = $ctr == strlen($encrypt_key) ?  0 : $ctr;    $tmp .= $ encrypt_key[$ctr]. ($txt[$i] ^ $encrypt_key[$ctr++]);    }    return urlencode(base64_encode(passport_key($tmp, $key)));    }    function passport_decrypt($txt, $key = 'liiu') {    $txt = passport_key(base64_decode(urldecode($txt)), $key);    $tmp = '';    for($i = 0;$ i < strlen($txt); $ i++) {    $md5 = $txt[$i];    $tmp .= $ txt[++$i] ^ $md5;    }    return $tmp;    }    function passport_key($txt, $encrypt_key) {    $encrypt_key = md5($encrypt_key);    $ctr = 0;    $tmp = '';    for($i = 0; $ i < strlen($txt); $ i++) {    $ctr = $ctr == strlen($encrypt_key) ?  0 : $ctr;    $tmp .= $ txt[$i] ^ $encrypt_key[$ctr++];    }    return $tmp;    }    $txt = "1";    $key = "testkey";    $encrypt = passport_encrypt($txt,$key);    $decrypt = passport_decrypt($encrypt,$key);    echo $encrypt."<br>";    echo $decrypt."<br>";    ?>

Fifth

 <? php   //Very powerful authcode encryption function, Discuz! Classic code (with detailed explanation) //$string in function authcode ($string, $operation, $key, $expiry): string, plaintext or ciphertext$ Operation: DECODE decrypt , others represent encryption$ Key: key$ Expiry: the validity period of the ciphertext. function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {      //Dynamic key length. The same plaintext will generate different ciphertext depending on the dynamic key $ckey_length = 4;      //Key $key = md5($key ? $key : $GLOBALS['discuz_auth_key']);      //Key a will participate in adding decrypt $keya = md5(substr($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)) : '';      //Key participating in the operation $cryptkey = $keya.md5($keya.$keyc);      $key_length = strlen($cryptkey);      //Clear text, the first 10 bits are used to save the time stamp, verify the validity of the data when decrypting, and 10 to 26 bits are used to save $keyb (key b), //The data integrity will be verified through this key during decryption //If it is decoded, it will start from the $key_length bit, because the dynamic key is saved in the $key_length bit before the ciphertext 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 = '';      $box = range(0, 255);      $rndkey = array();      //Generate Keybook for($i = 0; $ i <= 255; $i++) {      $rndkey[$i] = ord($cryptkey[$i % $key_length]);      }      //It seems very complicated to use a fixed algorithm to disrupt the key book and increase randomness. In fact, it does not increase the strength of ciphertext for($j = $i = 0; $ i < 256; $i++) {      $j = ($j + $box[$i] + $rndkey[$i]) % 256;      $tmp = $box[$i];      $box[$i] = $box[$j];      $box[$j] = $tmp;      }      //Core encryption and decryption part for($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;      //The key obtained from the key book is XOR, and then converted into characters $result .=  chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));      }      if($operation == 'DECODE') {     //To verify the validity of data, see the format of unencrypted plaintext if((substr($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 {      //The dynamic key is stored in the ciphertext, which is why the same plaintext can be decrypted after producing different ciphertext //Because the encrypted ciphertext may be some special characters, and the copy process may be lost, it is encoded with base64 return $keyc.str_replace('=', '', base64_encode($result));      }      }    $str = 'abcdef';    $key = 'www.helloweba.com';    echo authcode($str,'ENCODE',$key,0); // Encryption $str = '56f4yER1DI2WTzWMqsfPpS9hwyoJnFP2MpC8SOhRrxO7BOk';    echo authcode($str,'DECODE',$key,0); // decrypt ?>

Sixth

 <? php   //$string in function encrypt ($string, $operation, $key): the string to be encrypted and decrypted$ Operation: determine whether to encrypt or decrypt, E indicates encryption, D indicates decryption$ Key: key. function encrypt($string,$operation,$key=''){    $key=md5($key);    $key_length=strlen($key);    $string=$operation=='D'? base64_decode($string):substr(md5($string.$key),0,8).$ string;    $string_length=strlen($string);    $rndkey=$box=array();    $result='';    for($i=0;$ i<=255;$i++){    $rndkey[$i]=ord($key[$i%$key_length]);    $box[$i]=$i;    }    for($j=$i=0;$ i<256;$i++){    $j=($j+$box[$i]+$rndkey[$i])%256;    $tmp=$box[$i];    $box[$i]=$box[$j];    $box[$j]=$tmp;    }    for($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;    $result.= chr(ord($string[$i])^($box[($box[$a]+$box[$j])%256]));    }    if($operation=='D'){    if(substr($result,0,8)==substr(md5(substr($result,8).$ key),0,8)){    return substr($result,8);    }else{    return'';    }    }else{    return str_replace('=','',base64_encode($result));    }    }    $str = 'abc';    $key = 'www.helloweba.com';    $token = encrypt($str, 'E', $key);    Echo 'Encryption:'. encrypt ($str, 'E', $key); Echo 'Decryption:'. encrypt ($str, 'D', $key); ?>

This article is transferred from https://www.cnblogs.com/ningjiabing/p/11265204.html