fix minimum required length check for responder

Signed-off-by: leongross <leon.gross@9elements.com>

Author: leongross

src/commands/algorithms/mod.rs

@@ -188,8 +188,7 @@ impl NegotiateAlgorithmsReq {
             + size_of::<NegotiateAlgorithmsReq>()
             + total_alg_struct_len
             + total_ext_asym_len
-            + total_ext_hash_len
-            + 4) as u16
+            + total_ext_hash_len) as u16
     }
 
     /// Calculate the size of the extended algorithm structures in bytes.

src/commands/algorithms/response.rs

@@ -134,6 +134,13 @@ fn process_negotiate_algorithms_request<'a>(
         if fixed_alg_count != 2 {
             Err(ctx.generate_error_response(req_payload, ErrorCode::InvalidRequest, 0, None))?;
         }
+
+        // Skip extended algorithm structures embedded in this AlgStructure
+        for _ in 0..ext_alg_count {
+            ExtendedAlgo::decode(req_payload).map_err(|_| {
+                ctx.generate_error_response(req_payload, ErrorCode::InvalidRequest, 0, None)
+            })?;
+        }
     }
 
     // Total number of extended algorithms check