最常見的應用在使用者登入以及一些API資料交換的場景。最常見的應用在使用者登入以及一些API資料交換的場景。加密解密原理一般都是通過一定的加密解密演算法，將金鑰加入到演算法中，最終得到加密解密結果。
廢話不多說，直接上程式碼。
一、第一種針對於ID的可逆加密函數，也可以用作於邀請碼之類的，解密後的資料比較簡單
範例：lockcode(28)=》000X unlockcode('000X')=》28
//加密函數
function lockcode($code) {
static $source_string = 'E5FCDG3HQA4B1NOPIJ2RSTUV67MWX89KLYZ';
$num = $code;
$code = '';
while ( $num > 0) {
$mod = $num % 35;
$num = ($num - $mod) / 35;
$code = $source_string[$mod].$code;
}
if(empty($code[3]))
$code = str_pad($code,4,'0',STR_PAD_LEFT);
return $code;
}
//解密函數
function unlockcode($code) {
static $source_string = 'E5FCDG3HQA4B1NOPIJ2RSTUV67MWX89KLYZ';
if (strrpos($code, '0') !== false)
$code = substr($code, strrpos($code, '0')+1);
$len = strlen($code);
$code = strrev($code);
$num = 0;
for ($i=0; $i < $len; $i++) {
$num += strpos($source_string, $code[$i]) * pow(35, $i);
}
return $num;
}二、第二種是加密函數是我在網上搜尋來的，很好用，可逆加密，支援鹽值引數
範例：
encrypt('abcd','1234')=》nkiV93IfJ decrypt('nkiV93IfJ','1234')=》abcd
//加密函數
function encrypt($data,$key='CHENI'){
$chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
$nh = rand(0,64);
$ch = $chars[$nh];
$mdKey = md5($key.$ch);
$mdKey = substr($mdKey,$nh%8, $nh%8+7);
$data= base64_encode($data);
$tmp = '';
$i=0;$j=0;$k = 0;
for ($i=0; $i<strlen($data); $i++) {
$k = $k == strlen($mdKey) ? 0 : $k;
$j = ($nh+strpos($chars,$data[$i])+ord($mdKey[$k++]))%64;
$tmp .= $chars[$j];
}
return urlencode($ch.$tmp);
}
//解密函數
function decrypt($data,$key='CHENI'){
$txt = urldecode($data);
$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($tmp);
}三、第三種跟上面的比較類似，也支援鹽值引數
範例：encrypt('abcd','1234')=》mZPHxw== decrypt('mZPHxw==','1234')=》abcd
function encrypt($data, $key) {
$char="";
$str="";
$key = md5($key);
$x = 0;
$len = strlen($data);
$l = strlen($key);
for ($i = 0; $i < $len; $i++) {
if ($x == $l) { $x = 0; }
$char .= $key{$x};
$x++;
}
for ($i = 0; $i < $len; $i++){
$str .= chr(ord($data{$i}) + (ord($char{$i})) % 256);
}
return base64_encode($str);
}
function decrypt($data, $key) {
$key = md5($key);
$x = 0;
$data = base64_decode($data);
$len = strlen($data);
$l = strlen($key);
for ($i = 0; $i < $len; $i++) {
if ($x == $l){ $x = 0;}
$char .= substr($key, $x, 1);
$x++;
}
for ($i = 0; $i < $len; $i++){
if (ord(substr($data, $i, 1)) < ord(substr($char, $i, 1))){
$str .= chr((ord(substr($data, $i, 1)) + 256) - ord(substr($char, $i, 1)));
}else{
$str .= chr(ord(substr($data, $i, 1)) - ord(substr($char, $i, 1)));
}
}
return $str;
}四、這個是我用過最好用的一個了，discuz中使用的加密解密演算法
//加密演算法
function authcode($string,$key='',$operation=false,$expiry=0){
$ckey_length = 4;
$key = md5($key ? $key : DEFAULT_KEYS);
$keya = md5(substr($key, 0, 16));
$keyb = md5(substr($key, 16, 16));
$keyc = $ckey_length ? ($operation? substr($string, 0, $ckey_length):substr(md5(microtime()), -$ckey_length)) : '';
$cryptkey = $keya.md5($keya.$keyc);
$key_length = strlen($cryptkey);
$string = $operation? base64_decode(substr($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);
$rndkey = array();
for($i = 0; $i <= 255; $i++) {
$rndkey[$i] = ord($cryptkey[$i % $key_length]);
}
for($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($operation) {
if((substr($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 {
return $keyc.str_replace('=', '', base64_encode($result));
}
}
echo authcode('123456','key');
echo '<br>';
echo authcode('7d49kn9k07uSBZvha8as+/qm4UoLfpy88PFg12glPeDtlzc','key',true);
以上就是四種好用的PHP自定義加密函數（可逆/不可逆）的詳細內容，更多請關注TW511.COM其它相關文章！