fix(derive_key_from_path): check length of current_key_material (#2356)

Author: DeckerSU

mm2src/crypto/src/key_derivation.rs

@@ -133,7 +133,12 @@ pub(crate) fn derive_keys_for_mnemonic(
 
 /// Splits a path into its components and derives a key for each component.
 fn derive_key_from_path(master_node: &[u8], path: &str) -> MmResult<[u8; 32], KeyDerivationError> {
+    if master_node.len() < 64 {
+        return MmError::err(KeyDerivationError::InvalidKeyLength);
+    }
+
     let mut current_key_material = master_node.to_vec();
+
     for segment in path.split('/').filter(|s| !s.is_empty()) {
         let mut mac = HmacSha512::new_from_slice(&current_key_material[..32])
             .map_err(|_| KeyDerivationError::HmacInitialization)?;