wapp-cli/test/src/libs/base64.ts

微信小程序cli

export function base64Encode(str: string) { // need encodeURIComponent
    str = encodeURIComponent(str);
    let c1: number;
    let c2: number;
    let c3: number;
    const base64EncodeChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
    let i = 0;
    const len = str.length;
    let strin = '';
    while (i < len) {
        c1 = str.charCodeAt(i++) & 0xff;
        if (i === len) {
            strin += base64EncodeChars.charAt(c1 >> 2);
            strin += base64EncodeChars.charAt((c1 & 0x3) << 4);
            strin += '==';
            break;
        }
        c2 = str.charCodeAt(i++);
        if (i === len) {
            strin += base64EncodeChars.charAt(c1 >> 2);
            strin += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
            strin += base64EncodeChars.charAt((c2 & 0xF) << 2);
            strin += '=';
            break;
        }
        c3 = str.charCodeAt(i++);
        strin += base64EncodeChars.charAt(c1 >> 2);
        strin += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
        strin += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6));
        strin += base64EncodeChars.charAt(c3 & 0x3F);
    }
    return strin;
}

export function base64Decode(input: string) { // need decodeURIComponent
    const base64EncodeChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
    let output = '';
    let chr1: number;
    let chr2: number;
    let chr3: number;
    let enc1: number;
    let enc2: number;
    let enc3: number;
    let enc4: number;
    let i = 0;
    input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
    while (i < input.length) {
        enc1 = base64EncodeChars.indexOf(input.charAt(i++));
        enc2 = base64EncodeChars.indexOf(input.charAt(i++));
        enc3 = base64EncodeChars.indexOf(input.charAt(i++));
        enc4 = base64EncodeChars.indexOf(input.charAt(i++));
        chr1 = (enc1 << 2) | (enc2 >> 4);
        chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
        chr3 = ((enc3 & 3) << 6) | enc4;
        output = output + String.fromCharCode(chr1);
        if (enc3 !== 64) {
            output = output + String.fromCharCode(chr2);
        }
        if (enc4 !== 64) {
            output = output + String.fromCharCode(chr3);
        }
    }
    return decodeURIComponent(utf8Decode(output));
}

export function utf8Decode(utftext: string) { // utf-8解码
    let str: string = '';
    let i: number = 0;
    let c: number = 0;
    let c1 = 0;
    let c2 = 0;
    while (i < utftext.length) {
        c = utftext.charCodeAt(i);
        if (c < 128) {
            str += String.fromCharCode(c);
            i++;
        } else if ((c > 191) && (c < 224)) {
            c1 = utftext.charCodeAt(i + 1);
            str += String.fromCharCode(((c & 31) << 6) | (c1 & 63));
            i += 2;
        } else {
            c1 = utftext.charCodeAt(i + 1);
            c2 = utftext.charCodeAt(i + 2);
            str += String.fromCharCode(((c & 15) << 12) | ((c1 & 63) << 6) | (c2 & 63));
            i += 3;
        }
    }
    return str;
}