Akamai BMP native (`libakamaibmp.so`) string concealment

rotateString.js

const RotateDirection = Object.freeze({
	Left: -1,
	Right: 1,
});

// Init the ASCII character mapping table (equivalent to the large local_* arrays)
// /** @type {string[]} */
// const charMap = [];
// for(let i = 32; i < 127; i++) {
// 	// Skip " ' \ \x7F
// 	// if (i === 0x22 || i === 0x27 || i === 0x5C || i === 0x7F)
// 	if(i === 34 || i === 39 || i === 92 || i === 127) {
// 		continue;
// 	}
//
// 	charMap.push(String.fromCharCode(i));
// }

// Same as Akamai web
const charMap = " !#$%&()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[]^_`abcdefghijklmnopqrstuvwxyz{|}~";

/**
 * Rotates a string by substituting characters according to a mapping table.
 * @param {string} inputString String to rotate.
 * @param {number} seed Rotation seed.
 * @param {-1|0|1} direction Direction of rotation.
 * @returns {string} The rotated string.
 */
export function rotateString(inputString, seed, direction) {
	// If direction is 0 or string is empty, return the input string unchanged
	if(direction === 0 || inputString.length === 0) {
		return inputString;
	}

	let result = "";
	let currentSeed = seed;

	for(let i = 0; i < inputString.length; i++) {
		const char = inputString.charAt(i);
		const charIndex = charMap.indexOf(char);

		if(charIndex >= 0) {
			const offset = (currentSeed >> 8 & 0xFFFF) % charMap.length;

			if(direction < 1) {
				// Rotate left
				result += charMap[(charIndex - offset + charMap.length) % charMap.length];
			}
			else {
				// Rotate right
				result += charMap[(offset + charIndex) % charMap.length];
			}
		}
		else {
			// If character not in map, keep it unchanged
			result += char;
		}

		// Update the seed for the next character
		currentSeed = (currentSeed * 0x10101 + 0x415927) & 0x7FFFFF;
	}

	return result;
}

// const encrypted = rotateString("Hello World!", 12345, RotateDirection.Right);
// console.log("encrypted:", encrypted);
// const decrypted = rotateString(encrypted, 12345, RotateDirection.Left);
// console.log("decrypted:", decrypted);

// Found in Java_com_cyberfend_cyfsecurity_SensorDataBuilder_buildN → SensorDataBuilder::initializeKeys
const publicKeyString = rotateString("-j0ZOfGt%xoJ$.p%U<#~.Bnx#M\nk?-%PwI&Yg+>#|;0W1F{?0@WVJE+#8d 6]Jy2V2_<uqM:HbEfN8j/fy,L^(Prg}yLPi^Xp&ot43flfpXu`h AmT).TJ;*fdo^f;G@J84LcY!U-QKo[:]Be5)h>v6HN*rjS,^|*<K+(6||yxRxH:S#4>FSYVwK=z<_SH&*L+qWor+.fNpo_Q@o_8@t{KAqQxc#Z(%X,r^[q)~*;+b8Plb<Mrc\n8(&U++!|Z8HPGT5oa/BqAbX6", 63, RotateDirection.Left);
console.log(publicKeyString);