JavaScript ascii 到 utf-8 的转换问题与负数

我正在解密服务器端信息，我的加密以不同的语言工作，因此知道解密应该是什么？

为什么负数不正确，而正数却不正确？

运行示例：

输出格式：

str
pos
S[t]
str.charAt(str, pos + 1)
str.charCodeAt(pos + 1)

根据 GML 解密：

Input:
Str: ���
Key: 472
--------------
str: ���
pos: 0
ST: 195
char: ⮫
value: -94
str: ���
pos: 1
ST: 140
char: 
value: -18
str: ���
pos: 2
ST: 136
char: 
value: -21

服务器端等效项 （JS）：

Input: 
Str: ���
Key: 472
---------------
str: ���
pos: 0
ST: 195
char: �
value: 65533
str: ���
pos: 1
ST: 140
char: �
value: 65533
str: ���
pos: 2
ST: 136
char: 
value: NaN

信息如何到达输入：数据从 Server.js -> Client 传递.js其中标头被获取并通过 switch 语句放置，然后使用以下方法解析数据包的其余部分：

var Parser = require('binary-parser').Parser;
login: new Parser().skip(1)
        .string("command", StringOptions)
        .string("username", StringOptions)
        .string("password", StringOptions),

然后输入到方法：console.log（rc4（data.password， c.dhprivatekey））;

如果需要，我的代码：

function rc4(str, key) {
    var out = "";
    var len = byteCount(key);
    var S = [], j;
    var t;
    for(var i = 0; i < 256; i++) {
        S[i] = i;
    }
    j = 0;
    for( var i = 0; i< 256; i++) {
        var test = string_byte_at(key, (i % len) + 1)[0];
        if (typeof test != "number") {
        test = parseInt(test);
        }
        j = (j + S[i] + test % 256);
        temp = S[i];
        S[i] = S[j];
        S[j] = temp;
    }
    i = 0;
    j = 0;

    for (var pos = 0; pos < str.length; pos++) {
        i = (i + 1) % 256;
        j = (j + S[i]) % 256;
        var temp = S[i];
        S[i] = S[j];
        S[j] = temp;
        t = (S[i] + S[j]) % 256;
        out += str.charCodeAt(string_byte_at(str, pos + 1)[0] ^ S[t]);
    }
    return out;
    }

在 GML 中正确工作解密

 var str,key,out,len,i,S,j,temp,pos,t;
str = argument0;
key = string(argument1);
out = "";
len = string_byte_length(key);
for (i=0; i<256; i+=1) S[i] = i;
j = 0;
for (i=0; i<256; i+=1) {
    //show_debug_message(string_byte_at(key, (i mod len) + 1));
    j = (j + S[i] + string_byte_at(key,(i mod len)+1)) mod 256;
    temp = S[i];
    S[i] = S[j];
    S[j] = temp;
}
i = 0;
j = 0;
for (pos=0; pos < string_byte_length(str); pos+=1) {
    i = (i + 1) mod 256;
    j = (j + S[i]) mod 256;
    temp = S[i];
    S[i] = S[j];
    S[j] = temp;
    t = (S[i] + S[j]) mod 256;
    out += ansi_char(string_byte_at(str,pos+1) ^ S[t]);
}
return out;

http://docs.yoyogames.com/source/dadiospice/002_reference/strings/string_byte_at.html

http://docs.yoyogames.com/source/dadiospice/002_reference/strings/ansi_char.html

http://gmc.yoyogames.com/index.php?showtopic=554460