HotCRC内的HexToBase64()源码
本帖最后由 hotpower 于 2023-9-22 14:18 编辑菜农电子淘宝：https://hotcomlock.taobao.com/ 准备出书：http://hotcomlock.com/hotcomlock.html
function HexToBase64(hexstr)
{
var i, str, hexstrString;
hexstrString = "";
for (i = 0; i < hexstr.length; i += 8)
{
hexstrString += HexStrToBase64(hexstr.substr(i, 8));
}
return hexstrString;//输出3N个字节
}
function GetBase64Value(ch)
{
var value = 0;
if((ch >= "A") && (ch <= "Z")) {
value = ch.charCodeAt(0) - 0x41;
}
else if((ch >= "a") && (ch <= "z")) {
value = ch.charCodeAt(0) - 0x61 + 26;
}
else if((ch >= "0") && (ch <= "9")) {
value = ch.charCodeAt(0) - 0x30 + 52;
}
else if(ch == "+") {
value = 62;
}
else if(ch == "/") {
value = 63;
}
return value;
}
function HexStrToBase64(basehexstr)
{//输入4个字节
var c, a, t, x1, x2, x3, x4, str, hexstr;
str = HexToAscii(basehexstr);//4个字符
x1 = GetBase64Value(str.substr(0, 1));
x2 = GetBase64Value(str.substr(1, 1));
x3 = GetBase64Value(str.substr(2, 1));
x4 = GetBase64Value(str.substr(3, 1));
hexstr = "";
if(str.substr(3, 1) != "=") {
c = (x1 << 2) | (x2 >>> 4);
a = ((x2 & 0xf) << 4) | (x3 >>> 2);
t = ((x3 & 0x03) << 6) | x4;
hexstr = inttohex(c, 2);
hexstr += inttohex(a, 2);
hexstr += inttohex(t, 2);
}
else if(str.substr(2, 1) != "=") {
c = (x1 << 2) | (x2 >>> 4);
a = ((x2 & 0xf) << 4) | (x3 >>> 2);
hexstr = inttohex(c, 2);
hexstr += inttohex(a, 2);
}
else{
c = (x1 << 2) | (x2 >>> 4);
hexstr = inttohex(c, 2);
}
return hexstr;//输出3个字节
}
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