Add mnemonicToEntropy and entropyToMnemonic.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@multiversx/sdk-wallet",
-  "version": "4.5.1",
+  "version": "4.6.0",
   "description": "Wallet components for MultiversX",
   "main": "out/index.js",
   "types": "out/index.d.js",
@@ -22,7 +22,7 @@
   "dependencies": {
     "@multiversx/sdk-bls-wasm": "0.3.5",
     "bech32": "1.1.4",
-    "bip39": "3.0.2",
+    "bip39": "3.1.0",
     "blake2b": "2.1.3",
     "ed25519-hd-key": "1.1.2",
     "ed2curve": "0.3.0",

src/mnemonic.ts

@@ -1,4 +1,10 @@
-import { generateMnemonic, mnemonicToSeedSync, validateMnemonic } from "bip39";
+import {
+    entropyToMnemonic,
+    generateMnemonic,
+    mnemonicToEntropy,
+    mnemonicToSeedSync,
+    validateMnemonic,
+} from "bip39";
 import { derivePath } from "ed25519-hd-key";
 import { ErrWrongMnemonic } from "./errors";
 import { UserSecretKey } from "./userKeys";
@@ -14,7 +20,7 @@ export class Mnemonic {
     }
 
     static generate(): Mnemonic {
-        let text = generateMnemonic(MNEMONIC_STRENGTH);
+        const text = generateMnemonic(MNEMONIC_STRENGTH);
         return new Mnemonic(text);
     }
 
@@ -25,6 +31,11 @@ export class Mnemonic {
         return new Mnemonic(text);
     }
 
+    static fromEntropy(entropy: Uint8Array): Mnemonic {
+        const text = entropyToMnemonic(Buffer.from(entropy));
+        return new Mnemonic(text);
+    }
+
     public static assertTextIsValid(text: string) {
         let isValid = validateMnemonic(text);
 
@@ -45,6 +56,11 @@ export class Mnemonic {
         return this.text.split(" ");
     }
 
+    getEntropy(): Uint8Array {
+        const entropy = mnemonicToEntropy(this.text);
+        return Buffer.from(entropy, "hex");
+    }
+
     toString(): string {
         return this.text;
     }

src/users.spec.ts

@@ -26,6 +26,26 @@ describe("test user wallets", () => {
         assert.lengthOf(words, 24);
     });
 
+    it("should convert entropy to mnemonic and back", () => {
+        function testConversion(text: string, entropyHex: string) {
+            const entropyFromMnemonic = Mnemonic.fromString(text).getEntropy();
+            const mnemonicFromEntropy = Mnemonic.fromEntropy(Buffer.from(entropyHex, "hex"));
+
+            assert.equal(Buffer.from(entropyFromMnemonic).toString("hex"), entropyHex);
+            assert.equal(mnemonicFromEntropy.toString(), text);
+        }
+
+        testConversion(
+            "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about",
+            "00000000000000000000000000000000",
+        );
+
+        testConversion(
+            "moral volcano peasant pass circle pen over picture flat shop clap goat never lyrics gather prepare woman film husband gravity behind test tiger improve",
+            "8fbeb688d0529344e77d225898d4a73209510ad81d4ffceac9bfb30149bf387b",
+        );
+    });
+
     it("should derive keys", async () => {
         let mnemonic = Mnemonic.fromString(DummyMnemonic);