From 6b1eb943e21b01725798dbdb4d30ce6ec025fec6 Mon Sep 17 00:00:00 2001
From: Gav Wood <gav@ethcore.io>
Date: Tue, 12 Jan 2016 17:40:55 +0100
Subject: [PATCH] Add U512 type and a few conversions.

---
 src/bytes.rs  | 20 ++++++++--------
 src/crypto.rs |  7 ++++++
 src/uint.rs   | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 10 deletions(-)

diff --git a/src/bytes.rs b/src/bytes.rs
index 21d28e87c..8c56d6bf3 100644
--- a/src/bytes.rs
+++ b/src/bytes.rs
@@ -109,25 +109,25 @@ impl BytesConvertable for Vec<u8> {
 }
 
 macro_rules! impl_bytes_convertable_for_array {
-    ($zero: expr) => ();
-    ($len: expr, $($idx: expr),*) => {
-        impl BytesConvertable for [u8; $len] {
-            fn bytes(&self) -> &[u8] { self }
-        }
-        impl_bytes_convertable_for_array! { $($idx),* }
-    }
+	($zero: expr) => ();
+	($len: expr, $($idx: expr),*) => {
+		impl BytesConvertable for [u8; $len] {
+			fn bytes(&self) -> &[u8] { self }
+		}
+		impl_bytes_convertable_for_array! { $($idx),* }
+	}
 }
 
 // -1 at the end is not expanded
 impl_bytes_convertable_for_array! {
-        32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16,
-        15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, -1
+		32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16,
+		15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, -1
 }
 
 #[test]
 fn bytes_convertable() {
 	assert_eq!(vec![0x12u8, 0x34].bytes(), &[0x12u8, 0x34]);
-    assert_eq!([0u8; 0].bytes(), &[]);
+	assert_eq!([0u8; 0].bytes(), &[]);
 }
 
 /// Converts given type to its shortest representation in bytes
diff --git a/src/crypto.rs b/src/crypto.rs
index d13a53f53..9a27c68ae 100644
--- a/src/crypto.rs
+++ b/src/crypto.rs
@@ -1,4 +1,6 @@
 use hash::*;
+use bytes::*;
+use uint::*;
 use secp256k1::{key, Secp256k1};
 use rand::os::OsRng;
 
@@ -19,6 +21,11 @@ impl Signature {
 		ret[64] = v;
 		ret
 	}
+
+	/// Convert transaction to R, S and V components.
+	pub fn to_rsv(&self) -> (U256, U256, u8) {
+		(U256::from(&self.as_slice()[0..32]), U256::from(&self.as_slice()[32..64]), self[64])
+	}
 }
 
 #[derive(Debug)]
diff --git a/src/uint.rs b/src/uint.rs
index b7411fd30..6fefbd50d 100644
--- a/src/uint.rs
+++ b/src/uint.rs
@@ -462,9 +462,73 @@ macro_rules! construct_uint {
 	);
 }
 
+construct_uint!(U512, 8);
 construct_uint!(U256, 4);
 construct_uint!(U128, 2);
 
+impl From<U256> for U512 {
+	fn from(value: U256) -> U512 {
+		let U256(ref arr) = value;
+		let mut ret = [0; 8];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		ret[2] = arr[2];
+		ret[3] = arr[3];
+		U512(ret)
+	}
+}
+
+impl From<U512> for U256 {
+	fn from(value: U512) -> U256 {
+		let U512(ref arr) = value;
+		if arr[4] | arr[5] | arr[6] | arr[7] != 0 {
+			panic!("Overflow");
+		}
+		let mut ret = [0; 4];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		ret[2] = arr[2];
+		ret[3] = arr[3];
+		U256(ret)
+	}
+}
+
+impl From<U256> for U128 {
+	fn from(value: U256) -> U128 {
+		let U256(ref arr) = value;
+		if arr[2] | arr[3] != 0 {
+			panic!("Overflow");
+		}
+		let mut ret = [0; 2];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		U128(ret)
+	}
+}
+
+impl From<U512> for U128 {
+	fn from(value: U512) -> U128 {
+		let U512(ref arr) = value;
+		if arr[2] | arr[3] | arr[4] | arr[5] | arr[6] | arr[7] != 0 {
+			panic!("Overflow");
+		}
+		let mut ret = [0; 2];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		U128(ret)
+	}
+}
+
+impl From<U128> for U512 {
+	fn from(value: U128) -> U512 {
+		let U128(ref arr) = value;
+		let mut ret = [0; 8];
+		ret[0] = arr[0];
+		ret[1] = arr[1];
+		U512(ret)
+	}
+}
+
 impl From<U128> for U256 {
 	fn from(value: U128) -> U256 {
 		let U128(ref arr) = value;