@meshconnect/react-native-link-sdk/lib/utils/base64.js

Mesh Connect React Native SDK.

const keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
export const decode64 = (input) => {
    let output = '';
    let chr1, chr2, chr3 = '';
    let enc1, enc2, enc3, enc4 = '';
    let ind = 0;
    // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
    const base64test = /[^A-Za-z0-9+/=]/g;
    if (base64test.exec(input)) {
        throw new Error(`There were invalid base64 characters in the input text. Valid base64 characters are A-Z, a-z, 0-9, '+', '/',and '='`);
    }
    input = input.replace(/[^A-Za-z0-9+/=]/g, '');
    do {
        enc1 = keyStr.indexOf(input.charAt(ind++));
        enc2 = keyStr.indexOf(input.charAt(ind++));
        enc3 = keyStr.indexOf(input.charAt(ind++));
        enc4 = keyStr.indexOf(input.charAt(ind++));
        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);
        }
    } while (ind < input.length);
    return output;
};