import { RandomGeneratorUtils } from './RandomGeneratorUtils';
import { Utils } from './Utils';
export class CryptUtils {
/**
* @param string
*/
/* tslint:disable */
public static btoa (string: string): string {
const chars: string = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
let output: string = '';
string = encodeURIComponent(string).replace(/%([0-9A-F]{2})/g, (match, p1) => {
return String.fromCharCode(parseInt(`${Utils.hexadecimalPrefix}${p1}`));
});
for (
let block: number|undefined, charCode: number, idx: number = 0, map: string = chars;
string.charAt(idx | 0) || (map = '=', idx % 1);
output += map.charAt(63 & block >> 8 - idx % 1 * 8)
) {
charCode = string.charCodeAt(idx += 3/4);
Iif (charCode > 0xFF) {
throw new Error("'btoa' failed: The string to be encoded contains characters outside of the Latin1 range.");
}
block = block << 8 | charCode;
}
return output;
}
/* tslint:enable */
/**
* @param str
* @param length
* @returns {string[]}
*/
public static hideString(str: string, length: number): [string, string] {
const escapeRegExp: (s: string) => string = (s: string) =>
s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
const randomMerge: (s1: string, s2: string) => string = function (s1: string, s2: string): string {
let i1: number = -1,
i2: number = -1,
result: string = '';
while (i1 < s1.length || i2 < s2.length) {
if (RandomGeneratorUtils.getRandomFloat(0, 1) < 0.5 && i2 < s2.length) {
result += s2.charAt(++i2);
} else {
result += s1.charAt(++i1);
}
}
return result;
};
const randomString: string = RandomGeneratorUtils.getRandomGenerator().string({
length: length,
pool: RandomGeneratorUtils.randomGeneratorPool
});
let randomStringDiff: string = randomString.replace(
new RegExp('[' + escapeRegExp(str) + ']', 'g'),
'');
const randomStringDiffArray: string[] = randomStringDiff.split('');
RandomGeneratorUtils.getRandomGenerator().shuffle(randomStringDiffArray);
randomStringDiff = randomStringDiffArray.join('');
return [randomMerge(str, randomStringDiff), randomStringDiff];
}
/**
* RC4 symmetric cipher encryption/decryption
* https://gist.github.com/farhadi/2185197
*
* @param key
* @param string
* @returns {string}
*/
/* tslint:disable */
public static rc4 (string: string, key: string): string {
let s: number[] = [],
j: number = 0,
x: number,
result: string = '';
for (var i = 0; i < 256; i++) {
s[i] = i;
}
for (i = 0; i < 256; i++) {
j = (j + s[i] + key.charCodeAt(i % key.length)) % 256;
x = s[i];
s[i] = s[j];
s[j] = x;
}
i = 0;
j = 0;
for (let y = 0; y < string.length; y++) {
i = (i + 1) % 256;
j = (j + s[i]) % 256;
x = s[i];
s[i] = s[j];
s[j] = x;
result += String.fromCharCode(string.charCodeAt(y) ^ s[(s[i] + s[j]) % 256]);
}
return result;
}
/* tslint:enable */
}
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