Add offline signing support to CLI (#7104)

sdk/src/instruction.rs

@@ -117,7 +117,7 @@ impl Instruction {
 pub struct AccountMeta {
     /// An account's public key
     pub pubkey: Pubkey,
-    /// True if an Instruciton requires a Transaction signature matching `pubkey`.
+    /// True if an Instruction requires a Transaction signature matching `pubkey`.
     pub is_signer: bool,
     /// True if the `pubkey` can be loaded as a read-write account.
     pub is_writable: bool,

sdk/src/transaction.rs

@@ -51,6 +51,9 @@ pub enum TransactionError {
 
     /// Transaction contains an invalid account reference
     InvalidAccountIndex,
+
+    /// Transaction did not pass signature verification
+    SignatureFailure,
 }
 
 pub type Result<T> = result::Result<T, TransactionError>;
@@ -225,6 +228,21 @@ impl Transaction {
         }
     }
 
+    /// Verify the transaction
+    pub fn verify(&self) -> Result<()> {
+        if !self
+            .signatures
+            .iter()
+            .zip(&self.message.account_keys)
+            .map(|(signature, pubkey)| signature.verify(pubkey.as_ref(), &self.message_data()))
+            .all(|verify_result| verify_result)
+        {
+            Err(TransactionError::SignatureFailure)
+        } else {
+            Ok(())
+        }
+    }
+
     /// Get the positions of the pubkeys in `account_keys` associated with signing keypairs
     pub fn get_signing_keypair_positions<T: KeypairUtil>(
         &self,
@@ -246,6 +264,27 @@ impl Transaction {
             .collect())
     }
 
+    /// Replace all the signatures and pubkeys
+    pub fn replace_signatures(&mut self, signers: &[(Pubkey, Signature)]) -> Result<()> {
+        let num_required_signatures = self.message.header.num_required_signatures as usize;
+        if signers.len() != num_required_signatures
+            || self.signatures.len() != num_required_signatures
+            || self.message.account_keys.len() < num_required_signatures
+        {
+            return Err(TransactionError::InvalidAccountIndex);
+        }
+
+        signers
+            .iter()
+            .enumerate()
+            .for_each(|(i, (pubkey, signature))| {
+                self.signatures[i] = *signature;
+                self.message.account_keys[i] = *pubkey;
+            });
+
+        self.verify()
+    }
+
     pub fn is_signed(&self) -> bool {
         self.signatures
             .iter()