Limit stream name length.

linera-execution/src/lib.rs

@@ -75,6 +75,8 @@ pub use crate::{
 
 /// The maximum length of an event key in bytes.
 const MAX_EVENT_KEY_LEN: usize = 64;
+/// The maximum length of a stream name.
+const MAX_STREAM_NAME_LEN: usize = 64;
 
 /// An implementation of [`UserContractModule`].
 pub type UserContractCode = Arc<dyn UserContractModule + Send + Sync + 'static>;
@@ -170,6 +172,8 @@ pub enum ExecutionError {
     BlobNotFoundOnRead(BlobId),
     #[error("Event keys can be at most {MAX_EVENT_KEY_LEN} bytes.")]
     EventKeyTooLong,
+    #[error("Stream names can be at most {MAX_STREAM_NAME_LEN} bytes.")]
+    StreamNameTooLong,
 }
 
 /// The public entry points provided by the contract part of an application.

linera-execution/src/runtime.rs

@@ -32,7 +32,7 @@ use crate::{
     BaseRuntime, ContractRuntime, ExecutionError, ExecutionOutcome, FinalizeContext,
     MessageContext, OperationContext, QueryContext, RawExecutionOutcome, ServiceRuntime,
     UserApplicationDescription, UserApplicationId, UserContractInstance, UserServiceInstance,
-    MAX_EVENT_KEY_LEN,
+    MAX_EVENT_KEY_LEN, MAX_STREAM_NAME_LEN,
 };
 
 #[cfg(test)]
@@ -1271,6 +1271,10 @@ impl ContractRuntime for ContractSyncRuntimeHandle {
             key.len() <= MAX_EVENT_KEY_LEN,
             ExecutionError::EventKeyTooLong
         );
+        ensure!(
+            name.0.len() <= MAX_STREAM_NAME_LEN,
+            ExecutionError::StreamNameTooLong
+        );
         let application = this.current_application_mut();
         application.outcome.events.push((name, key, value));
         Ok(())