Check selectors too in whitelist

Author: antoniolocascio

basic_bootloader/src/bootloader/transaction/rlp_encoded/mod.rs

@@ -222,7 +222,7 @@ mod test {
 
     #[test]
     fn test_on_random_service() {
-        let input = hex::decode("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").unwrap();
+        let input = hex::decode("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").unwrap();
         let buffer = UsizeAlignedByteBox::<Global>::from_slice_in(&input, Global);
         let _tx =
             RlpEncodedTransaction::parse_from_buffer(buffer, 1, BOOTLOADER_FORMAL_ADDRESS).unwrap();

basic_bootloader/src/bootloader/transaction/rlp_encoded/transaction_types/service_tx.rs

@@ -16,16 +16,44 @@ use system_hooks::addresses_constants::{
 #[derive(Clone, Copy, Debug)]
 pub(crate) struct ServiceTx<'a> {
     pub(crate) to: &'a [u8; 20], // NOTE: has to be one of the addresses in SERVICE_DESTINATION_WHITELIST
-    pub(crate) data: &'a [u8],
+    pub(crate) data: &'a [u8], // NOTE: has start with one of the selectors in SERVICE_DESTINATION_WHITELIST
     salt: u64, // Some salt used by the server to identify service transactions. Ignored by ZKsync OS.
 }
 
-const SERVICE_DESTINATION_WHITELIST: &[B160] = &[
-    L2_INTEROP_ROOT_STORAGE_ADDRESS,
-    SYSTEM_CONTEXT_ADDRESS,
-    L2_INTEROP_CENTER_ADDRESS,
+/// Selector for
+/// addInteropRootsInBatch((uint256,uint256,bytes32[])[])
+/// -> 0xcca2f7bc
+const ADD_INTEROP_ROOTS_IN_BATCH_SELECTOR: [u8; 4] = [0xcc, 0xa2, 0xf7, 0xbc];
+
+/// Selector for
+/// setSettlementLayerChainId(uint256)
+/// -> 0x040203e6
+const SET_SL_CHAIN_ID_SELECTOR: [u8; 4] = [0x04, 0x02, 0x03, 0xe6];
+
+/// Selector for
+/// setInteropFee(uint256)
+/// -> 0x08273d8a
+const SET_INTEROP_FEE_SELECTOR: [u8; 4] = [0x09, 0x27, 0x3d, 0x8a];
+
+/// Pairs (destination, selector) that service transactions are allowed
+/// to interact with.
+const SERVICE_DESTINATION_WHITELIST: &[(B160, [u8; 4])] = &[
+    (
+        L2_INTEROP_ROOT_STORAGE_ADDRESS,
+        ADD_INTEROP_ROOTS_IN_BATCH_SELECTOR,
+    ),
+    (SYSTEM_CONTEXT_ADDRESS, SET_SL_CHAIN_ID_SELECTOR),
+    (L2_INTEROP_CENTER_ADDRESS, SET_INTEROP_FEE_SELECTOR),
 ];
 
+fn whitelisted(to: B160, data: &[u8]) -> bool {
+    let selector: [u8; 4] = match data.get(..4).and_then(|bytes| bytes.try_into().ok()) {
+        Some(selector) => selector,
+        None => return false,
+    };
+    SERVICE_DESTINATION_WHITELIST.contains(&(to, selector))
+}
+
 pub const SERVICE_TX_TYPE: u8 = 0x7d;
 
 impl<'a> EthereumTxType for ServiceTx<'a> {
@@ -46,12 +74,11 @@ impl<'a> RlpListDecode<'a> for ServiceTx<'a> {
 
         let to_b160 = B160::from_be_bytes(*to);
 
+        let data = r.bytes()?;
         // Validate whitelist
-        if !SERVICE_DESTINATION_WHITELIST.contains(&to_b160) {
+        if !whitelisted(to_b160, data) {
             return Err(InvalidTransaction::InvalidStructure);
         }
-
-        let data = r.bytes()?;
         let salt = r.u64()?;
         Ok(Self { to, data, salt })
     }
@@ -112,7 +139,7 @@ mod tests {
     #[test]
     fn to_in_whitelist_parses() {
         let to_bytes: [u8; 20] = L2_INTEROP_ROOT_STORAGE_ADDRESS.to_be_bytes();
-        let data: Vec<u8> = vec![0xde, 0xad, 0xbe, 0xef];
+        let data: Vec<u8> = ADD_INTEROP_ROOTS_IN_BATCH_SELECTOR.to_vec();
 
         let bytes = encode_service_tx(&to_bytes, &data, 0);