initial, fallable built-ins

Cargo.lock

@@ -175,6 +175,21 @@ name = "bloomchain"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "bn"
+version = "0.4.2"
+source = "git+https://github.com/paritytech/bn#78cf02fd7b35e4a2398fedd96f68c92953badea7"
+dependencies = [
+ "byteorder 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "byteorder"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "byteorder"
 version = "1.0.0"
@@ -382,6 +397,7 @@ version = "1.7.0"
 dependencies = [
  "bit-set 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bloomchain 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bn 0.4.2 (git+https://github.com/paritytech/bn)",
  "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "clippy 0.0.103 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2617,6 +2633,8 @@ dependencies = [
 "checksum bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aad18937a628ec6abcd26d1489012cc0e18c21798210f491af69ded9b881106d"
 "checksum blastfig 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "09640e0509d97d5cdff03a9f5daf087a8e04c735c3b113a75139634a19cfc7b2"
 "checksum bloomchain 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3f421095d2a76fc24cd3fb3f912b90df06be7689912b1bdb423caefae59c258d"
+"checksum bn 0.4.2 (git+https://github.com/paritytech/bn)" = "<none>"
+"checksum byteorder 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "0fc10e8cc6b2580fda3f36eb6dc5316657f812a3df879a44a66fc9f0fdbc4855"
 "checksum byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c40977b0ee6b9885c9013cd41d9feffdd22deb3bb4dc3a71d901cc7a77de18c8"
 "checksum bytes 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c129aff112dcc562970abb69e2508b40850dd24c274761bb50fb8a0067ba6c27"
 "checksum bytes 0.4.0-dev (git+https://github.com/carllerche/bytes)" = "<none>"

ethcore/Cargo.toml

@@ -45,6 +45,7 @@ ethcore-bloom-journal = { path = "../util/bloom" }
 hardware-wallet = { path = "../hw" }
 stats = { path = "../util/stats" }
 num = "0.1"
+bn = { git = "https://github.com/paritytech/bn" }
 
 [dependencies.hyper]
 git = "https://github.com/ethcore/hyper"

ethcore/res/ethereum/foundation.json

@@ -190,6 +190,8 @@
 		"0000000000000000000000000000000000000003": { "builtin": { "name": "ripemd160", "pricing": { "linear": { "base": 600, "word": 120 } } } },
 		"0000000000000000000000000000000000000004": { "builtin": { "name": "identity", "pricing": { "linear": { "base": 15, "word": 3 } } } },
 		"0000000000000000000000000000000000000005": { "builtin": { "name": "modexp", "activate_at": "0x7fffffffffffff", "pricing": { "modexp": { "divisor": 20 } } } },
+		"0000000000000000000000000000000000000006": { "builtin": { "name": "alt_bn128_add", "activate_at": "0x7fffffffffffff", "pricing": { "linear": { "base": 999999, "word": 0 } } } },
+		"0000000000000000000000000000000000000007": { "builtin": { "name": "alt_bn128_mul", "activate_at": "0x7fffffffffffff", "pricing": { "linear": { "base": 999999, "word": 0 } } } },
 		"3282791d6fd713f1e94f4bfd565eaa78b3a0599d": {
 			"balance": "1337000000000000000000"
 		},

ethcore/src/builtin.rs

@@ -27,10 +27,19 @@ use util::{U256, H256, Uint, Hashable, BytesRef};
 use ethkey::{Signature, recover as ec_recover};
 use ethjson;
 
+#[derive(Debug)]
+pub struct Error(pub String);
+
+impl From<&'static str> for Error {
+	fn from(val: &'static str) -> Self {
+		Error(val.to_owned())
+	}
+}
+
 /// Native implementation of a built-in contract.
 pub trait Impl: Send + Sync {
 	/// execute this built-in on the given input, writing to the given output.
-	fn execute(&self, input: &[u8], output: &mut BytesRef);
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error>;
 }
 
 /// A gas pricing scheme for built-in contracts.
@@ -102,7 +111,10 @@ impl Builtin {
 	pub fn cost(&self, input: &[u8]) -> U256 { self.pricer.cost(input) }
 
 	/// Simple forwarder for execute.
-	pub fn execute(&self, input: &[u8], output: &mut BytesRef) { self.native.execute(input, output) }
+	pub fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> { 
+		self.native.execute(input, output);
+		Ok(()) 
+	}
 
 	/// Whether the builtin is activated at the given block number.
 	pub fn is_active(&self, at: u64) -> bool { at >= self.activate_at }
@@ -172,14 +184,21 @@ struct Ripemd160;
 #[derive(Debug)]
 struct ModexpImpl;
 
+#[derive(Debug)]
+struct Bn128AddImpl;
+
+#[derive(Debug)]
+struct Bn128MulImpl;
+
 impl Impl for Identity {
-	fn execute(&self, input: &[u8], output: &mut BytesRef) {
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> {
 		output.write(0, input);
+		Ok(())
 	}
 }
 
 impl Impl for EcRecover {
-	fn execute(&self, i: &[u8], output: &mut BytesRef) {
+	fn execute(&self, i: &[u8], output: &mut BytesRef) -> Result<(), Error> {
 		let len = min(i.len(), 128);
 
 		let mut input = [0; 128];
@@ -192,7 +211,7 @@ impl Impl for EcRecover {
 
 		let bit = match v[31] {
 			27 | 28 if &v.0[..31] == &[0; 31] => v[31] - 27,
-			_ => return,
+			_ => { return Ok(()); },
 		};
 
 		let s = Signature::from_rsv(&r, &s, bit);
@@ -203,11 +222,13 @@ impl Impl for EcRecover {
 				output.write(12, &r[12..r.len()]);
 			}
 		}
+
+		Ok(())
 	}
 }
 
 impl Impl for Sha256 {
-	fn execute(&self, input: &[u8], output: &mut BytesRef) {
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> {
 		let mut sha = Sha256Digest::new();
 		sha.input(input);
 
@@ -215,11 +236,13 @@ impl Impl for Sha256 {
 		sha.result(&mut out);
 
 		output.write(0, &out);
+
+		Ok(())
 	}
 }
 
 impl Impl for Ripemd160 {
-	fn execute(&self, input: &[u8], output: &mut BytesRef) {
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> {
 		let mut sha = Ripemd160Digest::new();
 		sha.input(input);
 
@@ -227,11 +250,13 @@ impl Impl for Ripemd160 {
 		sha.result(&mut out[12..32]);
 
 		output.write(0, &out);
+
+		Ok(())
 	}
 }
 
 impl Impl for ModexpImpl {
-	fn execute(&self, input: &[u8], output: &mut BytesRef) {
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> {
 		let mut reader = input.chain(io::repeat(0));
 		let mut buf = [0; 32];
 
@@ -294,9 +319,43 @@ impl Impl for ModexpImpl {
 			let res_start = mod_len - bytes.len();
 			output.write(res_start, &bytes);
 		}
+
+		Ok(())
 	}
 }
 
+impl Impl for Bn128AddImpl {
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> {
+		use bn::{Fq, AffineG1, G1};
+
+		let mut buf = [0u8; 32];
+		let mut next_coord = |reader: &mut io::Chain<&[u8], io::Repeat>| {
+			reader.read_exact(&mut buf[..]).expect("reading from zero-extended memory cannot fail; qed");
+			Fq::from_slice(&input[0..32])
+		};
+
+		let mut padded_input = input.chain(io::repeat(0));
+
+		let p1x = next_coord(&mut padded_input).map_err(|_| Error::from("Invalid p1 x coordinate"))?;
+		let p1y = next_coord(&mut padded_input).map_err(|_| Error::from("Invalid p1 y coordinate"))?;
+		let p1: G1 = AffineG1::new(p1x, p1y).into();
+
+		let p2x = next_coord(&mut padded_input).map_err(|_| Error::from("Invalid p2 x coordinate"))?;
+		let p2y = next_coord(&mut padded_input).map_err(|_| Error::from("Invalid p2 y coordinate"))?;
+		let p2: G1 = AffineG1::new(p2x, p2y).into();
+
+		let sum  = AffineG1::from_jacobian(p1 + p2).expect("Sum of two valid points is a valid point also; qed");
+
+		Ok(())
+	}	
+}
+
+impl Impl for Bn128MulImpl {
+	fn execute(&self, input: &[u8], output: &mut BytesRef) -> Result<(), Error> {
+		Ok(())
+	}	
+}
+
 #[cfg(test)]
 mod tests {
 	use super::{Builtin, Linear, ethereum_builtin, Pricer, Modexp};
@@ -574,4 +633,4 @@ mod tests {
 		b.execute(&i[..], &mut BytesRef::Fixed(&mut o[..]));
 		assert_eq!(i, o);
 	}
-}
+}

ethcore/src/evm/evm.rs

@@ -20,6 +20,7 @@ use std::{ops, cmp, fmt};
 use util::{U128, U256, U512, Uint, trie};
 use action_params::ActionParams;
 use evm::Ext;
+use builtin;
 
 /// Evm errors.
 #[derive(Debug, Clone, PartialEq)]
@@ -59,6 +60,7 @@ pub enum Error {
 		/// What was the stack limit
 		limit: usize
 	},
+	BuiltIn(String),
 	/// Returned on evm internal error. Should never be ignored during development.
 	/// Likely to cause consensus issues.
 	Internal(String),
@@ -70,6 +72,12 @@ impl From<Box<trie::TrieError>> for Error {
 	}
 }
 
+impl From<builtin::Error> for Error {
+	fn from(err: builtin::Error) -> Self {
+		Error::BuiltIn(err.0)
+	}	
+}
+
 impl fmt::Display for Error {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		use self::Error::*;
@@ -79,6 +87,7 @@ impl fmt::Display for Error {
 			BadInstruction { .. } => "Bad instruction",
 			StackUnderflow { .. } => "Stack underflow",
 			OutOfStack { .. } => "Out of stack",
+			BuiltIn { .. } => "Built-in failed",
 			Internal(ref msg) => msg,
 		};
 		message.fmt(f)

ethcore/src/executive.rs

@@ -276,7 +276,7 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
 
 			let cost = builtin.cost(data);
 			if cost <= params.gas {
-				builtin.execute(data, &mut output);
+				builtin.execute(data, &mut output)?;
 				self.state.discard_checkpoint();
 
 				// trace only top level calls to builtins to avoid DDoS attacks
@@ -497,6 +497,7 @@ impl<'a, B: 'a + StateBackend> Executive<'a, B> {
 				| Err(evm::Error::BadJumpDestination {..})
 				| Err(evm::Error::BadInstruction {.. })
 				| Err(evm::Error::StackUnderflow {..})
+				| Err(evm::Error::BuiltIn {..})
 				| Err(evm::Error::OutOfStack {..}) => {
 					self.state.revert_to_checkpoint();
 			},

ethcore/src/lib.rs

@@ -107,6 +107,7 @@ extern crate ethabi;
 extern crate hardware_wallet;
 extern crate stats;
 extern crate num;
+extern crate bn;
 
 #[macro_use]
 extern crate log;

ethcore/src/types/trace_types/error.rs

@@ -34,7 +34,9 @@ pub enum Error {
 	/// `StackUnderflow` when there is not enough stack elements to execute instruction
 	StackUnderflow,
 	/// When execution would exceed defined Stack Limit
-	OutOfStack,
+	OutOfStack,	
+	/// When builtin contract failed on input data
+	BuiltIn,
 	/// Returned on evm internal error. Should never be ignored during development.
 	/// Likely to cause consensus issues.
 	Internal,
@@ -48,6 +50,7 @@ impl<'a> From<&'a EvmError> for Error {
 			EvmError::BadInstruction { .. } => Error::BadInstruction,
 			EvmError::StackUnderflow { .. } => Error::StackUnderflow,
 			EvmError::OutOfStack { .. } => Error::OutOfStack,
+			EvmError::BuiltIn { .. } => Error::OutOfStack,
 			EvmError::Internal(_) => Error::Internal,
 		}
 	}
@@ -68,6 +71,7 @@ impl fmt::Display for Error {
 			BadInstruction => "Bad instruction",
 			StackUnderflow => "Stack underflow",
 			OutOfStack => "Out of stack",
+			BuiltIn => "Built-in failed",
 			Internal => "Internal error",
 		};
 		message.fmt(f)
@@ -84,6 +88,7 @@ impl Encodable for Error {
 			StackUnderflow => 3,
 			OutOfStack => 4,
 			Internal => 5,
+			BuiltIn => 6,
 		};
 
 		s.append_internal(&value);