Check length of validator name in metadata

.changelog/unreleased/improvements/3779-restrict-metadat-name-len.md

@@ -0,0 +1,2 @@
+- Check the string length of the validator name in provided metadata.
+  ([\#3779](https://github.com/anoma/namada/pull/3779))

crates/apps_lib/src/config/genesis/transactions.rs

@@ -1417,6 +1417,15 @@ pub fn validate_validator_account(
             );
         }
     }
+    if let Some(name) = metadata.name.as_ref() {
+        if name.len() as u64 > MAX_VALIDATOR_METADATA_LEN {
+            panic!(
+                "The name metadata of the validator with address {} is too \
+                 long, must be within {MAX_VALIDATOR_METADATA_LEN} characters",
+                signed_tx.data.address
+            );
+        }
+    }
 
     // Check signature
     let mut is_valid = {

crates/sdk/src/tx.rs

@@ -846,6 +846,18 @@ pub async fn build_validator_metadata_change(
             }
         }
     }
+    if let Some(name) = name.as_ref() {
+        if name.len() as u64 > MAX_VALIDATOR_METADATA_LEN {
+            edisplay_line!(
+                context.io(),
+                "Name provided is too long, must be within \
+                 {MAX_VALIDATOR_METADATA_LEN} characters"
+            );
+            if !tx_args.force {
+                return Err(Error::from(TxSubmitError::MetadataTooLong));
+            }
+        }
+    }
 
     // If there's a new commission rate, it must be valid
     if let Some(rate) = commission_rate.as_ref() {