Merge pull request #12 from zama-ai/fix/fix-array-transform

Fix/fix array transform

package.json

@@ -1,6 +1,6 @@
 {
   "name": "fhevmjs",
-  "version": "0.0.3",
+  "version": "0.0.4",
   "description": "fhEVM SDK for blockchain using TFHE",
   "main": "lib/node.js",
   "browser": "lib/web.js",

src/sdk/decrypt.test.ts

@@ -19,7 +19,7 @@ describe('decrypt', () => {
   it('decrypts a Uint8Array value', async () => {
     const keypair = sodium.crypto_box_keypair();
 
-    const value = 28482;
+    const value = 10;
     const ciphertext = sodium.crypto_box_seal(numberToBytes(value), keypair.publicKey);
     const cleartext = decrypt(keypair, ciphertext);
     expect(cleartext).toBe(value);

src/sdk/index.test.ts

@@ -123,7 +123,7 @@ describe('token', () => {
     const kp = instance.getTokenSignature(contractAddress);
     expect(kp!.publicKey).toBe(publicKey);
 
-    const value = 8238290348;
+    const value = 89290;
     const ciphertext = sodium.crypto_box_seal(numberToBytes(value), publicKey, 'hex');
     const cleartext = instance.decrypt(contractAddress, ciphertext);
     expect(cleartext).toBe(value);

src/utils.ts

@@ -9,27 +9,26 @@ export const fromHexString = (hexString: string): Uint8Array => {
 export const toHexString = (bytes: Uint8Array) =>
   bytes.reduce((str, byte) => str + byte.toString(16).padStart(2, '0'), '');
 
-export const numberToBytes = (number: number) => {
-  // you can use constant number of bytes by using 8 or 4
-  const len = Math.ceil(Math.log2(number) / 8);
-  const byteArray = new Uint8Array(len);
-
-  for (let index = 0; index < byteArray.length; index++) {
-    const byte = number & 0xff;
-    byteArray[index] = byte;
-    number = (number - byte) / 256;
+export const numberToBytes = (uint32Value: number) => {
+  const byteArrayLength = Math.ceil(Math.log2(uint32Value + 1) / 8);
+  const byteArray = new Uint8Array(byteArrayLength);
+
+  for (let i = byteArrayLength - 1; i >= 0; i--) {
+    byteArray[i] = uint32Value & 0xff;
+    uint32Value >>= 8;
   }
 
   return byteArray;
 };
 
-export const bytesToNumber = (byteArray: Uint8Array) => {
-  let result = 0;
-  for (let i = byteArray.length - 1; i >= 0; i--) {
-    result = result * 256 + byteArray[i];
+export const bytesToNumber = (byteArray: Uint8Array): number => {
+  let uint32Value = 0;
+
+  for (let i = 0; i < byteArray.length; i++) {
+    uint32Value |= byteArray[i] << (8 * (byteArray.length - 1 - i));
   }
 
-  return result;
+  return uint32Value;
 };
 
 export const isAddress = function (address: string) {