From 77570c48e9962d93d903fbbf881c869ef31e12c7 Mon Sep 17 00:00:00 2001
From: Pravdyvy <awxrvtb@gmail.com>
Date: Wed, 26 Nov 2025 14:27:09 +0200
Subject: [PATCH] fix: suggestions 2

---
 .../key_management/key_tree/chain_index.rs    | 25 +++++++++++++++++-
 .../key_management/key_tree/keys_private.rs   | 26 ++++++++++++++-----
 2 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/key_protocol/src/key_management/key_tree/chain_index.rs b/key_protocol/src/key_management/key_tree/chain_index.rs
index 1ab431a..9d641b3 100644
--- a/key_protocol/src/key_management/key_tree/chain_index.rs
+++ b/key_protocol/src/key_management/key_tree/chain_index.rs
@@ -49,9 +49,15 @@ impl Display for ChainIndex {
     }
 }
 
+impl Default for ChainIndex {
+    fn default() -> Self {
+        ChainIndex::from_str("/").expect("Root parsing failure")
+    }
+}
+
 impl ChainIndex {
     pub fn root() -> Self {
-        ChainIndex::from_str("/").unwrap()
+        ChainIndex::default()
     }
 
     pub fn chain(&self) -> &[u32] {
@@ -95,6 +101,23 @@ mod tests {
         assert_eq!(chain_id.chain(), &[257]);
     }
 
+    #[test]
+    fn test_chain_id_deser_failure_no_root() {
+        let chain_index_error = ChainIndex::from_str("257").err().unwrap();
+
+        assert!(matches!(chain_index_error, ChainIndexError::NoRootFound));
+    }
+
+    #[test]
+    fn test_chain_id_deser_failure_int_parsing_failure() {
+        let chain_index_error = ChainIndex::from_str("/hello").err().unwrap();
+
+        assert!(matches!(
+            chain_index_error,
+            ChainIndexError::ParseIntError(_)
+        ));
+    }
+
     #[test]
     fn test_chain_id_next_in_line_correct() {
         let chain_id = ChainIndex::from_str("/257").unwrap();
diff --git a/key_protocol/src/key_management/key_tree/keys_private.rs b/key_protocol/src/key_management/key_tree/keys_private.rs
index c29f7d6..c13a6b3 100644
--- a/key_protocol/src/key_management/key_tree/keys_private.rs
+++ b/key_protocol/src/key_management/key_tree/keys_private.rs
@@ -20,8 +20,14 @@ impl KeyNode for ChildKeysPrivate {
     fn root(seed: [u8; 64]) -> Self {
         let hash_value = hmac_sha512::HMAC::mac(seed, "NSSA_master_priv");
 
-        let ssk = SecretSpendingKey(*hash_value.first_chunk::<32>().unwrap());
-        let ccc = *hash_value.last_chunk::<32>().unwrap();
+        let ssk = SecretSpendingKey(
+            *hash_value
+                .first_chunk::<32>()
+                .expect("hash_value is 64 bytes, must be safe to get first 32"),
+        );
+        let ccc = *hash_value
+            .last_chunk::<32>()
+            .expect("hash_value is 64 bytes, must be safe to get last 32");
 
         let nsk = ssk.generate_nullifier_secret_key();
         let isk = ssk.generate_incoming_viewing_secret_key();
@@ -57,9 +63,9 @@ impl KeyNode for ChildKeysPrivate {
                 .outgoing_viewing_secret_key
                 .into(),
         )
-        .unwrap()
+        .expect("Key generated as scalar, must be valid representation")
             + Scalar::from_repr(self.value.0.private_key_holder.nullifier_secret_key.into())
-                .unwrap()
+                .expect("Key generated as scalar, must be valid representation")
                 * Scalar::from_repr(
                     self.value
                         .0
@@ -67,7 +73,7 @@ impl KeyNode for ChildKeysPrivate {
                         .incoming_viewing_secret_key
                         .into(),
                 )
-                .unwrap();
+                .expect("Key generated as scalar, must be valid representation");
         let mut input = vec![];
 
         input.extend_from_slice(b"NSSA_seed_priv");
@@ -76,8 +82,14 @@ impl KeyNode for ChildKeysPrivate {
 
         let hash_value = hmac_sha512::HMAC::mac(input, self.ccc);
 
-        let ssk = SecretSpendingKey(*hash_value.first_chunk::<32>().unwrap());
-        let ccc = *hash_value.last_chunk::<32>().unwrap();
+        let ssk = SecretSpendingKey(
+            *hash_value
+                .first_chunk::<32>()
+                .expect("hash_value is 64 bytes, must be safe to get first 32"),
+        );
+        let ccc = *hash_value
+            .last_chunk::<32>()
+            .expect("hash_value is 64 bytes, must be safe to get last 32");
 
         let nsk = ssk.generate_nullifier_secret_key();
         let isk = ssk.generate_incoming_viewing_secret_key();