diff --git a/speck48_96ctr.ts b/speck48_96ctr.ts new file mode 100644 index 0000000..1b84606 --- /dev/null +++ b/speck48_96ctr.ts @@ -0,0 +1,41 @@ +import speck from 'generic-speck'; +import { blake2bHex } from 'blakejs'; + +const speck48_96 = speck({ bits: 24, rounds: 23, rightRotations: 8, leftRotations: 3 }); + +export function getKey(kStr: string): number[] { + const key96bit = blake2bHex(kStr, undefined, 12); + return [ + parseInt(key96bit.slice(0, 6), 16), + parseInt(key96bit.slice(6, 12), 16), + parseInt(key96bit.slice(12, 18), 16), + parseInt(key96bit.slice(18, 24), 16) + ]; +} + +export function encrypt(ptStr: string, key: number[]): number[] { + const nonce = globalThis.crypto.getRandomValues(new Uint32Array(1))[0] & 0xFFFFFF; + + const ctArr = Array.from(ptStr, (c, i) => { + const ctrBlock = nonce * 16777216 + (i & 0xFFFFFF); + const ks = speck48_96.encrypt(ctrBlock, key); + return (c.codePointAt(0)! ^ ks) >>> 0; + }); + + return [nonce, ...ctArr]; +} + +export function decrypt(numArr: number[], key: number[]): string { + if (!numArr || numArr.length === 0) return ''; + + const nonce = numArr[0]; + const ctArr = numArr.slice(1); + + return ctArr.map((ct, i) => { + const ctrBlock = nonce * 16777216 + (i & 0xFFFFFF); + const ks = speck48_96.encrypt(ctrBlock, key); + const cp = (ct ^ ks) >>> 0; + try { return String.fromCodePoint(cp); } + catch { return ''; } + }).join(''); +}