Reject TXs when there is a mismatch (#6236)

automerge

sdk/src/message.rs

@@ -127,6 +127,7 @@ fn get_program_ids(instructions: &[Instruction]) -> Vec<Pubkey> {
 pub struct MessageHeader {
     /// The number of signatures required for this message to be considered valid. The
     /// signatures must match the first `num_required_signatures` of `account_keys`.
+    /// NOTE: Serialization-related changes must be paired with the direct read at sigverify.
     pub num_required_signatures: u8,
 
     /// The last num_credit_only_signed_accounts of the signed keys are credit-only accounts.
@@ -142,6 +143,7 @@ pub struct MessageHeader {
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
 pub struct Message {
     /// The message header, identifying signed and credit-only `account_keys`
+    /// NOTE: Serialization-related changes must be paired with the direct read at sigverify.
     pub header: MessageHeader,
 
     /// All the account keys used by this transaction

sdk/src/transaction.rs

@@ -60,6 +60,7 @@ pub type Result<T> = result::Result<T, TransactionError>;
 pub struct Transaction {
     /// A set of digital signatures of `account_keys`, `program_ids`, `recent_blockhash`, and `instructions`, signed by the first
     /// signatures.len() keys of account_keys
+    /// NOTE: Serialization-related changes must be paired with the direct read at sigverify.
     #[serde(with = "short_vec")]
     pub signatures: Vec<Signature>,