validate mnemonic in mnemonic_to_hex_seed (iotaledger#568)

* validate mnemonic

* add changes file

.changes/mnemonic.md

@@ -0,0 +1,5 @@
+---
+"nodejs-binding": patch
+---
+
+Validate mnemonic in mnemonicToHexSeed()

iota-client/src/client.rs

@@ -39,7 +39,7 @@ use zeroize::Zeroize;
 use crate::builder::TIPS_INTERVAL;
 #[cfg(feature = "mqtt")]
 use rumqttc::AsyncClient as MqttClient;
-#[cfg(any(feature = "mqtt", not(feature = "wasm")))]
+#[cfg(feature = "mqtt")]
 use tokio::sync::watch::{Receiver as WatchReceiver, Sender as WatchSender};
 #[cfg(not(feature = "wasm"))]
 use tokio::{
@@ -558,6 +558,9 @@ impl Client {
 
     /// Returns a hex encoded seed for a mnemonic.
     pub fn mnemonic_to_hex_seed(mnemonic: &str) -> Result<String> {
+        // first we check if the mnemonic is valid to give meaningful errors
+        crypto::keys::bip39::wordlist::verify(mnemonic, &crypto::keys::bip39::wordlist::ENGLISH)
+            .map_err(|e| crate::Error::InvalidMnemonic(format!("{:?}", e)))?;
         let mut mnemonic_seed = [0u8; 64];
         mnemonic_to_seed(mnemonic, &"", &mut mnemonic_seed);
         Ok(hex::encode(mnemonic_seed))

iota-client/src/error.rs

@@ -140,4 +140,7 @@ pub enum Error {
     /// Tokio task join error
     #[error("{0}")]
     TaskJoinError(#[from] tokio::task::JoinError),
+    /// Invalid mnemonic error
+    #[error("Invalid mnemonic {0}")]
+    InvalidMnemonic(String),
 }

iota-client/tests/mnemonic.rs

@@ -0,0 +1,14 @@
+// Copyright 2021 IOTA Stiftung
+// SPDX-License-Identifier: Apache-2.0
+
+use iota_client::{Client, Result};
+
+#[tokio::test]
+async fn mnemonic() -> Result<()> {
+    let mnemonic = Client::generate_mnemonic()?;
+    assert!(Client::mnemonic_to_hex_seed(&mnemonic).is_ok());
+    assert!(Client::mnemonic_to_hex_seed("until fire hat mountain zoo grocery real deny advance change marble taste goat ivory wheat bubble panic banner tattoo client ticket action race rocket").is_ok());
+    assert!(Client::mnemonic_to_hex_seed("fire until hat mountain zoo grocery real deny advance change marble taste goat ivory wheat bubble panic banner tattoo client ticket action race rocket").is_err());
+    assert!(Client::mnemonic_to_hex_seed("invalid mnemonic").is_err());
+    Ok(())
+}