compare wtxid commitment

keep-starknet-strange · Sep 8, 2024 · 25edef4 · 25edef4
1 parent fb5f5f8
commit 25edef4
Showing 1 changed file with 111 additions and 12 deletions.
diff --git a/src/validation/coinbase.cairo b/src/validation/coinbase.cairo
@@ -11,7 +11,7 @@ const MINIMUM_WITNESS_COMMITMENT: u32 = 38;
 
 /// Validates coinbase transaction.
 pub fn validate_coinbase(
-    tx: @Transaction, total_fees: u64, block_height: u32, _wtxid_commitment: Hash,
+    tx: @Transaction, total_fees: u64, block_height: u32, wtxid_commitment: Hash,
 ) -> Result<(), ByteArray> {
     // Validate the coinbase input
     // Ensure there is exactly one coinbase input
@@ -72,32 +72,41 @@ pub fn validate_coinbase(
         if *tx.is_segwit {
             let outputs = *tx.outputs;
             let mut is_wtxid_commitment_present: bool = false;
+            let mut extracted_wtxid_commitment: ByteArray = "";
             let mut i = 0;
+            let mut x = 6;
 
             while i < outputs.len() {
                 let pk_script = *outputs[i].pk_script;
 
-                // check for OP_RETURN and 6-byte fixed prefix 0xaa21a9ed
+                // check for OP_RETURN and the fixed prefix "0xaa21a9ed"
                 if pk_script.len() >= MINIMUM_WITNESS_COMMITMENT
                     && pk_script[0] == 0x6a
                     && pk_script[1] == 0x24
                     && pk_script[2] == 0xaa
                     && pk_script[3] == 0x21
                     && pk_script[4] == 0xa9
                     && pk_script[5] == 0xed {
-                    //TODO: compare the wtxid commitment
-                    println!("wtxid commitment present");
+                    // get wtxid commitment
+                    while x < pk_script.len() {
+                        extracted_wtxid_commitment.append_word(pk_script[x].into(), 1);
+                        x += 1;
+                    };
+
                     is_wtxid_commitment_present = true;
+                    break;
                 }
                 i += 1;
             };
 
             if !is_wtxid_commitment_present {
                 return Result::Err("No wtxid commitment found");
             }
+
+            if !(extracted_wtxid_commitment == wtxid_commitment.into()) {
+                return Result::Err("Wrong wtxid commitment");
+            }
         }
-        /// Verify wTXID Commitment
-    // Locate the OP_RETURN output, ensure that it contains the wTXID commitment ()
     }
 
     Result::Ok(())
@@ -111,7 +120,7 @@ fn compute_block_reward(block_height: u32) -> u64 {
 #[cfg(test)]
 mod tests {
     use crate::types::transaction::{TxIn, TxOut, Transaction, OutPoint};
-    use crate::utils::hex::from_hex;
+    use crate::utils::{hex::from_hex, hash::Hash};
     use super::{compute_block_reward, validate_coinbase};
 
     // Ref implementation here:
@@ -738,7 +747,52 @@ mod tests {
     }
 
     #[test]
-    fn test_validate_coinbase_segwit_output() {
+    fn test_validate_coinbase_segwit_output_with_no_wtxid_commitment() {
+        let tx = Transaction {
+            version: 1,
+            is_segwit: true,
+            inputs: array![
+                TxIn {
+                    script: @from_hex(
+                        "0320a107046f0a385a632f4254432e434f4d2ffabe6d6dbdd0ee86f9a1badfd0aa1b3c9dac8d90840cf973f7b2590d6c9adde1a6e0974a010000000000000001283da9a172020000000000"
+                    ),
+                    sequence: 4294967295,
+                    previous_output: OutPoint {
+                        txid: 0x0_u256.into(),
+                        vout: 0xffffffff_u32,
+                        data: Default::default(),
+                        block_height: Default::default(),
+                        block_time: Default::default(),
+                        is_coinbase: false,
+                    },
+                    witness: array![
+                        from_hex("0000000000000000000000000000000000000000000000000000000000000000")
+                    ]
+                        .span(),
+                }
+            ]
+                .span(),
+            outputs: array![
+                TxOut {
+                    value: 0_u64,
+                    pk_script: @from_hex(
+                        "10109f4b82aa3ed7ec9d02a2a90246478b3308c8b85daf62fe501d58d05727a4"
+                    ),
+                    cached: false,
+                }
+            ]
+                .span(),
+            lock_time: 0
+        };
+
+        let total_fees = 0_u64;
+        let block_height = 500_000;
+
+        validate_coinbase(@tx, total_fees, block_height, Default::default()).unwrap_err();
+    }
+
+    #[test]
+    fn test_validate_coinbase_segwit_output_with_wrong_wtxid_commitment() {
         let tx = Transaction {
             version: 1,
             is_segwit: true,
@@ -778,12 +832,24 @@ mod tests {
 
         let total_fees = 0_u64;
         let block_height = 500_000;
+        let wtxid_commitment = Hash {
+            value: [
+                0x10109985,
+                0x82aa3ed7,
+                0xec9d02a2,
+                0xa9024647,
+                0x8b3308c8,
+                0xb85daf62,
+                0xfe501d58,
+                0xd05727a4
+            ]
+        };
 
-        validate_coinbase(@tx, total_fees, block_height, Default::default()).unwrap();
+        validate_coinbase(@tx, total_fees, block_height, wtxid_commitment).unwrap_err();
     }
 
     #[test]
-    fn test_validate_coinbase_segwit_output_with_no_wtxid_commitment() {
+    fn test_validate_coinbase_segwit_output() {
         let tx = Transaction {
             version: 1,
             is_segwit: true,
@@ -812,7 +878,28 @@ mod tests {
                 TxOut {
                     value: 0_u64,
                     pk_script: @from_hex(
-                        "10109f4b82aa3ed7ec9d02a2a90246478b3308c8b85daf62fe501d58d05727a4"
+                        "0000000000000000000000000000000000000000000000000000000000000000"
+                    ),
+                    cached: false,
+                },
+                TxOut {
+                    value: 0_u64,
+                    pk_script: @from_hex(
+                        "6a24aa21a9ed10109f4b82aa3ed7ec9d02a2a90246478b3308c8b85daf62fe501d58d05727a4"
+                    ),
+                    cached: false,
+                },
+                TxOut {
+                    value: 0_u64,
+                    pk_script: @from_hex(
+                        "0000000000000000000000000000000000000000000000000000000000000000"
+                    ),
+                    cached: false,
+                },
+                TxOut {
+                    value: 0_u64,
+                    pk_script: @from_hex(
+                        "0000000000000000000000000000000000000000000000000000000000000000"
                     ),
                     cached: false,
                 }
@@ -823,7 +910,19 @@ mod tests {
 
         let total_fees = 0_u64;
         let block_height = 500_000;
+        let wtxid_commitment = Hash {
+            value: [
+                0x10109f4b,
+                0x82aa3ed7,
+                0xec9d02a2,
+                0xa9024647,
+                0x8b3308c8,
+                0xb85daf62,
+                0xfe501d58,
+                0xd05727a4
+            ]
+        };
 
-        validate_coinbase(@tx, total_fees, block_height, Default::default()).unwrap_err();
+        validate_coinbase(@tx, total_fees, block_height, wtxid_commitment).unwrap();
     }
 }