age & coinbase

Cargo.lock

@@ -611,6 +611,7 @@ dependencies = [
  "primitives 0.1.0",
  "serialization 0.1.0",
  "test-data 0.1.0",
+ "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

chain/src/transaction.rs

@@ -245,6 +245,11 @@ impl Transaction {
 	pub fn outputs(&self) -> &[TransactionOutput] {
 		&self.outputs
 	}
+
+	pub fn is_coinbase(&self) -> bool {
+		if self.inputs.len() != 1 { return false; }
+		self.inputs[0].previous_output.hash.is_zero() && self.inputs[0].previous_output.index == 0xffffffff
+	}
 }
 
 #[cfg(test)]

primitives/src/hash.rs

@@ -124,6 +124,11 @@ macro_rules! impl_hash {
 			pub fn size() -> usize {
 				$size
 			}
+
+			pub fn is_zero(&self) -> bool {
+				for b in self.0.iter() { if *b != 0 { return false; } }
+				return true;
+			}
 		}
 	}
 }

verification/Cargo.toml

@@ -13,3 +13,5 @@ parking_lot = "0.3"
 linked-hash-map = "0.3"
 test-data = { path = "../test-data" }
 byteorder = "0.5"
+time = "0.1"
+

verification/src/chain_verifier.rs

@@ -8,6 +8,8 @@ use super::{Verify, VerificationResult, Chain, Error};
 use primitives::hash::H256;
 use byteorder::{LittleEndian, BigEndian, ByteOrder};
 
+const BLOCK_MAX_FUTURE: i64 = 2 * 60 * 60; // 2 hours
+
 pub struct ChainVerifier {
 	store: Arc<db::Store>,
 }
@@ -55,6 +57,10 @@ fn check_nbits(hash: &H256, n_bits: u32) -> bool {
 	return true;
 }
 
+fn age(protocol_time: u32) -> i64 {
+	::time::get_time().sec - protocol_time as i64
+}
+
 impl Verify for ChainVerifier {
 	fn verify(&self, block: &chain::Block) -> VerificationResult {
 		let hash = block.hash();
@@ -69,6 +75,16 @@ impl Verify for ChainVerifier {
 			return Err(Error::Pow);
 		}
 
+		// check if block timestamp is not far in the future
+		if age(block.header().time) < -BLOCK_MAX_FUTURE {
+			return Err(Error::Timestamp);
+		}
+
+		// check first transaction is a coinbase transaction
+		if !block.transactions()[0].is_coinbase() {
+			return Err(Error::Coinbase)
+		}
+
 		let parent = match self.store.block(BlockRef::Hash(block.header().previous_header_hash.clone())) {
 			Some(b) => b,
 			None => { return Ok(Chain::Orphan); }

verification/src/lib.rs

@@ -7,6 +7,7 @@ extern crate serialization;
 extern crate parking_lot;
 extern crate linked_hash_map;
 extern crate byteorder;
+extern crate time;
 
 #[cfg(test)]
 extern crate ethcore_devtools as devtools;