177 lines
6.7 KiB
JavaScript
177 lines
6.7 KiB
JavaScript
"use strict";
|
||
Object.defineProperty(exports, "__esModule", { value: true });
|
||
exports.BinaryFF1 = exports.FF1 = exports.encryptBlock = void 0;
|
||
const utils_js_1 = require("./utils.js");
|
||
// Format-preserving encryption algorithm (FPE-FF1) specified in NIST Special Publication 800-38G.
|
||
// https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38G.pdf
|
||
// Utils
|
||
function toBytesBE(num, length) {
|
||
let hex = num.toString(16);
|
||
hex = hex.length & 1 ? `0${hex}` : hex;
|
||
if (length)
|
||
hex = hex.padStart(length * 2, '00');
|
||
const len = hex.length / 2;
|
||
const u8 = new Uint8Array(len);
|
||
for (let j = 0, i = 0; i < hex.length && i < len * 2; i += 2, j++)
|
||
u8[j] = parseInt(hex[i] + hex[i + 1], 16);
|
||
return u8;
|
||
}
|
||
function fromBytesBE(bytes) {
|
||
let value = 0n;
|
||
for (let i = bytes.length - 1, j = 0; i >= 0; i--, j++)
|
||
value += (BigInt(bytes[i]) & 255n) << (8n * BigInt(j));
|
||
return value;
|
||
}
|
||
function mod(a, b) {
|
||
const result = a % b;
|
||
return result >= 0 ? result : b + result;
|
||
}
|
||
// AES stuff
|
||
const BLOCK_LEN = 16;
|
||
const IV = new Uint8Array(BLOCK_LEN);
|
||
async function encryptBlock(msg, key) {
|
||
if (key.length !== 16 && key.length !== 32)
|
||
throw new Error('Invalid key length');
|
||
const cr = (0, utils_js_1.getWebcryptoSubtle)();
|
||
const mode = { name: `AES-CBC`, length: key.length * 8 };
|
||
const wKey = await cr.importKey('raw', key, mode, true, ['encrypt']);
|
||
const cipher = await cr.encrypt({ name: `aes-cbc`, iv: IV, counter: IV, length: 64 }, wKey, msg);
|
||
return new Uint8Array(cipher).subarray(0, 16);
|
||
}
|
||
exports.encryptBlock = encryptBlock;
|
||
function NUMradix(radix, data) {
|
||
let res = 0n;
|
||
for (let i of data)
|
||
res = res * BigInt(radix) + BigInt(i);
|
||
return res;
|
||
}
|
||
async function getRound(radix, key, tweak, x) {
|
||
if (radix > 2 ** 16 - 1)
|
||
throw new Error(`Invalid radix: ${radix}`);
|
||
// radix**minlen ≥ 100
|
||
const minLen = Math.ceil(Math.log(100) / Math.log(radix));
|
||
const maxLen = 2 ** 32 - 1;
|
||
// 2 ≤ minlen ≤ maxlen < 2**32
|
||
if (2 > minLen || minLen > maxLen || maxLen >= 2 ** 32)
|
||
throw new Error('Invalid radix: 2 ≤ minlen ≤ maxlen < 2**32');
|
||
if (x.length < minLen || x.length > maxLen)
|
||
throw new Error('X is outside minLen..maxLen bounds');
|
||
const u = Math.floor(x.length / 2);
|
||
const v = x.length - u;
|
||
const b = Math.ceil(Math.ceil(v * Math.log2(radix)) / 8);
|
||
const d = 4 * Math.ceil(b / 4) + 4;
|
||
const padding = mod(-tweak.length - b - 1, 16);
|
||
// P = [1]1 || [2]1 || [1]1 || [radix]3 || [10]1 || [u mod 256]1 || [n]4 || [t]4.
|
||
const P = new Uint8Array([1, 2, 1, 0, 0, 0, 10, u, 0, 0, 0, 0, 0, 0, 0, 0]);
|
||
const view = new DataView(P.buffer);
|
||
view.setUint16(4, radix, false);
|
||
view.setUint32(8, x.length, false);
|
||
view.setUint32(12, tweak.length, false);
|
||
// Q = T || [0](−t−b−1) mod 16 || [i]1 || [NUMradix(B)]b.
|
||
const PQ = new Uint8Array(P.length + tweak.length + padding + 1 + b);
|
||
PQ.set(P);
|
||
P.fill(0);
|
||
PQ.set(tweak, P.length);
|
||
const round = async (A, B, i, decrypt = false) => {
|
||
// Q = ... || [i]1 || [NUMradix(B)]b.
|
||
PQ[PQ.length - b - 1] = i;
|
||
if (b)
|
||
PQ.set(toBytesBE(NUMradix(radix, B), b), PQ.length - b);
|
||
// PRF
|
||
let r = new Uint8Array(16);
|
||
for (let j = 0; j < PQ.length / BLOCK_LEN; j++) {
|
||
for (let i = 0; i < BLOCK_LEN; i++)
|
||
r[i] ^= PQ[j * BLOCK_LEN + i];
|
||
r.set(await encryptBlock(r, key));
|
||
}
|
||
// Let S be the first d bytes of the following string of ⎡d/16⎤ blocks:
|
||
// R || CIPHK(R ⊕[1]16) || CIPHK(R ⊕[2]16) ...CIPHK(R ⊕[⎡d / 16⎤ – 1]16).
|
||
let s = Array.from(r);
|
||
for (let j = 1; s.length < d; j++) {
|
||
const block = toBytesBE(BigInt(j), 16);
|
||
for (let k = 0; k < BLOCK_LEN; k++)
|
||
block[k] ^= r[k];
|
||
s.push(...Array.from(await encryptBlock(block, key)));
|
||
}
|
||
let y = fromBytesBE(Uint8Array.from(s.slice(0, d)));
|
||
s.fill(0);
|
||
if (decrypt)
|
||
y = -y;
|
||
const m = i % 2 === 0 ? u : v;
|
||
let c = mod(NUMradix(radix, A) + y, BigInt(radix) ** BigInt(m));
|
||
// STR(radix, m, c)
|
||
const C = Array(m).fill(0);
|
||
for (let i = 0; i < m; i++, c /= BigInt(radix))
|
||
C[m - 1 - i] = Number(c % BigInt(radix));
|
||
A.fill(0);
|
||
A = B;
|
||
B = C;
|
||
return [A, B];
|
||
};
|
||
const destroy = () => PQ.fill(0);
|
||
return { u, round, destroy };
|
||
}
|
||
const EMPTY_BUF = new Uint8Array([]);
|
||
function FF1(radix, key, tweak = EMPTY_BUF) {
|
||
const PQ = getRound.bind(null, radix, key, tweak);
|
||
return {
|
||
async encrypt(x) {
|
||
const { u, round, destroy } = await PQ(x);
|
||
let [A, B] = [x.slice(0, u), x.slice(u)];
|
||
for (let i = 0; i < 10; i++)
|
||
[A, B] = await round(A, B, i);
|
||
destroy();
|
||
const res = A.concat(B);
|
||
A.fill(0);
|
||
B.fill(0);
|
||
return res;
|
||
},
|
||
async decrypt(x) {
|
||
const { u, round, destroy } = await PQ(x);
|
||
// The FF1.Decrypt algorithm is similar to the FF1.Encrypt algorithm;
|
||
// the differences are in Step 6, where:
|
||
// 1) the order of the indices is reversed,
|
||
// 2) the roles of A and B are swapped
|
||
// 3) modular addition is replaced by modular subtraction, in Step 6vi.
|
||
let [B, A] = [x.slice(0, u), x.slice(u)];
|
||
for (let i = 9; i >= 0; i--)
|
||
[A, B] = await round(A, B, i, true);
|
||
destroy();
|
||
const res = B.concat(A);
|
||
A.fill(0);
|
||
B.fill(0);
|
||
return res;
|
||
},
|
||
};
|
||
}
|
||
exports.FF1 = FF1;
|
||
// Binary string which encodes each byte in little-endian byte order
|
||
const binLE = {
|
||
encode(bytes) {
|
||
const x = [];
|
||
for (let i = 0; i < bytes.length; i++) {
|
||
for (let j = 0, tmp = bytes[i]; j < 8; j++, tmp >>= 1)
|
||
x.push(tmp & 1);
|
||
}
|
||
return x;
|
||
},
|
||
decode(b) {
|
||
if (b.length % 8)
|
||
throw new Error('Invalid binary string');
|
||
const res = new Uint8Array(b.length / 8);
|
||
for (let i = 0, j = 0; i < res.length; i++) {
|
||
res[i] = b[j++] | (b[j++] << 1) | (b[j++] << 2) | (b[j++] << 3);
|
||
res[i] |= (b[j++] << 4) | (b[j++] << 5) | (b[j++] << 6) | (b[j++] << 7);
|
||
}
|
||
return res;
|
||
},
|
||
};
|
||
function BinaryFF1(key, tweak = EMPTY_BUF) {
|
||
const ff1 = FF1(2, key, tweak);
|
||
return {
|
||
encrypt: async (x) => binLE.decode(await ff1.encrypt(binLE.encode(x))),
|
||
decrypt: async (x) => binLE.decode(await ff1.decrypt(binLE.encode(x))),
|
||
};
|
||
}
|
||
exports.BinaryFF1 = BinaryFF1;
|
||
//# sourceMappingURL=ff1.js.map
|