Introduce Ed25519 verify as an external.

substrate/native-runtime/support/src/lib.rs

@@ -3,6 +3,9 @@ extern crate environmental;
 extern crate polkadot_state_machine;
 extern crate tiny_keccak;
 
+use std::fmt;
+use primitives::ed25519;
+
 pub use std::vec::Vec;
 pub use std::rc::Rc;
 pub use std::cell::RefCell;
@@ -11,7 +14,6 @@ pub use std::slice;
 pub use std::mem::{size_of, transmute, swap, uninitialized};
 
 pub use polkadot_state_machine::Externalities;
-use std::fmt;
 
 // TODO: use the real error, not NoError.
 
@@ -63,9 +65,9 @@ pub fn storage_into<T: Sized>(_key: &[u8]) -> Option<T> {
 	}).unwrap_or(None)
 }
 
-pub fn set_storage(_key: &[u8], _value: &[u8]) {
+pub fn set_storage(key: &[u8], value: &[u8]) {
 	ext::with(|holder|
-		holder.ext.set_storage(_key.to_vec(), _value.to_vec())
+		holder.ext.set_storage(key.to_vec(), value.to_vec())
 	);
 }
 
@@ -79,6 +81,11 @@ pub fn chain_id() -> u64 {
 /// Conduct a Keccak-256 hash of the given data.
 pub use tiny_keccak::keccak256;
 
+/// Verify a ed25519 signature.
+pub fn ed25519_verify(sig: &[u8; 64], msg: &[u8], pubkey: &[u8; 32]) -> bool {
+	ed25519::verify(&sig[..], msg, &pubkey[..])
+}
+
 /// Execute the given closure with global function available whose functionality routes into the
 /// externalities `ext`. Forwards the value that the closure returns.
 pub fn with_externalities<R, F: FnOnce() -> R>(ext: &mut Externalities<Error=NoError>, f: F) -> R {

substrate/primitives/src/ed25519.rs

@@ -15,6 +15,17 @@ impl<'a> ::std::fmt::Display for HexDisplay<'a> {
 	}
 }
 
+pub fn verify(sig: &[u8], message: &[u8], public: &[u8]) -> bool {
+	let public_key = untrusted::Input::from(public);
+	let msg = untrusted::Input::from(message);
+	let sig = untrusted::Input::from(sig);
+
+	match signature::verify(&signature::ED25519, public_key, msg, sig) {
+		Ok(_) => true,
+		_ => false,
+	}
+}
+
 /// A public key.
 #[derive(PartialEq, Clone, Debug)]
 pub struct Public ([u8; 32]);

substrate/wasm-runtime/support/src/lib.rs

@@ -30,6 +30,7 @@ extern "C" {
 	fn ext_get_storage_into(key_data: *const u8, key_len: u32, value_data: *mut u8, value_len: u32) -> u32;
 	fn ext_chain_id() -> u64;
 	fn ext_keccak256(data: *const u8, len: u32, out: *mut u8);
+	fn ext_ed25519_verify(msg_data: *const u8, msg_len: u32, sig_data: *const u8, pubkey_data: *const u8) -> u32;
 }
 
 pub fn storage(key: &[u8]) -> Vec<u8> {
@@ -89,6 +90,16 @@ pub fn keccak256(data: &[u8]) -> [u8; 32] {
 	}
 }
 
+/// Verify a ed25519 signature.
+pub fn ed25519_verify(sig: &[u8; 64], msg: &[u8], pubkey: &[u8; 32]) -> bool {
+	unsafe {
+		match ext_ed25519_verify(&msg[0], msg.len() as u32, &sig[0], &pubkey[0]) {
+			0 => false,
+			_ => true,
+		}
+	}
+}
+
 pub trait Printable {
 	fn print(self);
 }