我为所有基64的目的都负有书面替代职能。

参看:

function base64_decode($input) {
    $keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    $chr1 = $chr2 = $chr3 = "";
    $enc1 = $enc2 = $enc3 = $enc4 = "";
    $i = 0;
    $output = "";

    // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
    $filter = $input;
    $input = preg_replace("[^A-Za-z0-9+/=]", "", $input);
    if ($filter != $input) {
        return false;
    }

    do {
        $enc1 = strpos($keyStr, substr($input, $i++, 1));
        $enc2 = strpos($keyStr, substr($input, $i++, 1));
        $enc3 = strpos($keyStr, substr($input, $i++, 1));
        $enc4 = strpos($keyStr, substr($input, $i++, 1));
        $chr1 = ($enc1 << 2) | ($enc2 >> 4);
        $chr2 = (($enc2 & 15) << 4) | ($enc3 >> 2);
        $chr3 = (($enc3 & 3) << 6) | $enc4;
        $output = $output . chr((int) $chr1);
        if ($enc3 != 64) {
            $output = $output . chr((int) $chr2);
        }
        if ($enc4 != 64) {
            $output = $output . chr((int) $chr3);
        }
        $chr1 = $chr2 = $chr3 = "";
        $enc1 = $enc2 = $enc3 = $enc4 = "";
    } while ($i < strlen($input));
    return urldecode($output);
}

function base64_encode($data) {
    $b64 =  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/= ;
    $o1 = $o2 = $o3 = $h1 = $h2 = $h3 = $h4 = $bits = $i = 0;
    $ac = 0;
    $enc =   ;
    $tmp_arr = array();
    if (!$data) {
        return data;
    }
    do {
    // pack three octets into four hexets
    $o1 = charCodeAt($data, $i++);
    $o2 = charCodeAt($data, $i++);
    $o3 = charCodeAt($data, $i++);
    $bits = $o1 << 16 | $o2 << 8 | $o3;
    $h1 = $bits >> 18 & 0x3f;
    $h2 = $bits >> 12 & 0x3f;
    $h3 = $bits >> 6 & 0x3f;
    $h4 = $bits & 0x3f;
    // use hexets to index into b64, and append result to encoded string
    $tmp_arr[$ac++] = charAt($b64, $h1).charAt($b64, $h2).charAt($b64, $h3).charAt($b64, $h4);
    } while ($i < strlen($data));
    $enc = implode($tmp_arr,   );
    $r = (strlen($data) % 3);
    return ($r ? substr($enc, 0, ($r - 3)) . substr( === , $r) : $enc);
}

function charCodeAt($data, $char) {
    return ord(substr($data, $char, 1));
}

function charAt($data, $char) {
    return substr($data, $char, 1);
}

But don t forget the charCodeAt and the charAt function. They are both necessary for base64_encode. The two functions base64_encode and base64_decode both are working like the inbuilt PHP functions. But only use them, if the inbuilt ones are not availible because they re not as fast as the inbuilt ones.

希望!

只是为了评论Jankal的回答而注册的,但可以没有声誉。

最后一行功能基础64 - 扬卡尔的答复中的编码

return ($r ? substr($enc, 0, ($r - 3)) : $enc) . substr( === , ($r || 3));

单位:0美元、1美元或2美元。 据我所知,按逻辑计算(r code 3)的表述价值为3美元,其他2起案件的美元=0美元和美元,但实际上(PHP 5.6/7.0)这一表述的价值总是等于1美元,因此,我们的BASE64-encoded string总以2 = 符号结束,这无疑是错误的。

我的解决办法:

return ($r ? substr($enc, 0, ($r - 3)) . substr( === , $r) : $enc);

function myencode($input)
    {
    $CODES = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    // the result/encoded string, the padding string, and the pad count
    $r = "";
    $p= "";
    $c = strlen($input) % 3;

    // add a right zero pad to make this string a multiple of 3 characters
    if ($c > 0) 
    {
        for (; $c < 3; $c++)
     {
        $p .= "=";
        $input .= "";
     }
    }

    // increment over the length of the string, three characters at a time
    for ($c = 0; $c < strlen($input); $c += 3) {

// we add newlines after every 76 output characters, according to the MIME specs

        if ($c > 0 && ($c / 3 * 4) % 76 == 0)
        $r += "
";

// these three 8-bit (ASCII) characters become one 24-bit number
$n = (ord($input[$c]) << 16) + (ord($input[$c +1]) << 8) + (ord($input[$c +2]));


        // this 24-bit number gets separated into four 6-bit numbers
        $n1 = $n >> 18 & 63;
        $n2 = $n >> 12 & 63;
        $n3 = $n >> 6 & 63;
        $n4 = $n & 63;

 // those four 6-bit numbers are used as indices into the base64 character list

 $r .= "" . $CODES[$n1] . $CODES[$n2] . $CODES[$n3] . $CODES[$n4];

    }
    return substr($r,0,(strlen($r)-strlen($p))) . $p;
    }  



 function mydecode($input) {

 $CODES = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

// remove/ignore any characters not in the base64 characters list
    // or the pad character -- particularly newlines

    $input= str_replace("[^" . $CODES . "=]","",$input);

    // replace any incoming padding with a zero pad (the  A  character is  zero)
    $p = ($input[strlen($input) - 1] ==  =  ?($input[strlen($input) - 2] ==  =  ? "AA" : "A") : "");

    $r = "";
    $input = substr($input,0,(strlen($input) - strlen($p))) . $p;
// increment over the length of this encoded string, four characters at a time
    for ($c = 0; $c < strlen($input); $c += 4) {

// each of these four characters represents a 6-bit index in the
// base64 characters list which, when concatenated, will give the
// 24-bit number for the original 3 characters

         $n=(strpos($CODES,$input[$c]) << 18)
         +  (strpos($CODES,$input[$c+1]) << 12)
         +  (strpos($CODES,$input[$c+2]) << 6)
         +  (strpos($CODES,$input[$c+3]));


// split the 24-bit number into the original three 8-bit (ASCII) characters
$r .= "" . chr(($n >> 16) & 0xFF) . chr((($n >> 8) & 0xFF)) . chr(($n & 0xFF));

    }
    // remove any zero pad that was added to make this a multiple of 24 bits
        return substr($r,0, strlen($r)- strlen($p));
    }

这个问题令人不安。

请修改 主办或要求它们消除这一安全问题