Feat: Convert speck48_96ctr to TypeScript

Co-authored-by: gemini-3.7-flash <noreply@google.com>

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('');
+}