Move remaining nonce utils from runtime to SDK

sdk/src/nonce/mod.rs

@@ -2,3 +2,4 @@ pub mod account;
 pub use account::{create_account, Account};
 pub mod state;
 pub use state::State;
+pub mod utils;

sdk/src/nonce/utils.rs

@@ -0,0 +1,86 @@
+use solana_sdk::{
+    account::Account,
+    account_utils::StateMut,
+    fee_calculator::FeeCalculator,
+    hash::Hash,
+    nonce::{state::Versions, State},
+};
+
+pub fn verify_nonce_account(acc: &Account, hash: &Hash) -> bool {
+    match StateMut::<Versions>::state(acc).map(|v| v.convert_to_current()) {
+        Ok(State::Initialized(ref data)) => *hash == data.blockhash,
+        _ => false,
+    }
+}
+
+pub fn fee_calculator_of(account: &Account) -> Option<FeeCalculator> {
+    let state = StateMut::<Versions>::state(account)
+        .ok()?
+        .convert_to_current();
+    match state {
+        State::Initialized(data) => Some(data.fee_calculator),
+        _ => None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use solana_sdk::{
+        account_utils::State as AccountUtilsState,
+        hash::Hash,
+        nonce::{account::with_test_keyed_account, Account as NonceAccount, State},
+        sysvar::{recent_blockhashes::create_test_recent_blockhashes, rent::Rent},
+    };
+    use std::collections::HashSet;
+
+    #[test]
+    fn verify_nonce_ok() {
+        with_test_keyed_account(42, true, |nonce_account| {
+            let mut signers = HashSet::new();
+            signers.insert(nonce_account.signer_key().unwrap());
+            let state: State = nonce_account.state().unwrap();
+            // New is in Uninitialzed state
+            assert_eq!(state, State::Uninitialized);
+            let recent_blockhashes = create_test_recent_blockhashes(0);
+            let authorized = nonce_account.unsigned_key();
+            nonce_account
+                .initialize_nonce_account(&authorized, &recent_blockhashes, &Rent::free())
+                .unwrap();
+            assert!(verify_nonce_account(
+                &nonce_account.account.borrow(),
+                &recent_blockhashes[0].blockhash,
+            ));
+        });
+    }
+
+    #[test]
+    fn verify_nonce_bad_acc_state_fail() {
+        with_test_keyed_account(42, true, |nonce_account| {
+            assert!(!verify_nonce_account(
+                &nonce_account.account.borrow(),
+                &Hash::default()
+            ));
+        });
+    }
+
+    #[test]
+    fn verify_nonce_bad_query_hash_fail() {
+        with_test_keyed_account(42, true, |nonce_account| {
+            let mut signers = HashSet::new();
+            signers.insert(nonce_account.signer_key().unwrap());
+            let state: State = nonce_account.state().unwrap();
+            // New is in Uninitialzed state
+            assert_eq!(state, State::Uninitialized);
+            let recent_blockhashes = create_test_recent_blockhashes(0);
+            let authorized = nonce_account.unsigned_key();
+            nonce_account
+                .initialize_nonce_account(&authorized, &recent_blockhashes, &Rent::free())
+                .unwrap();
+            assert!(!verify_nonce_account(
+                &nonce_account.account.borrow(),
+                &recent_blockhashes[1].blockhash,
+            ));
+        });
+    }
+}