From 8ea73507c5974ca7a7a7e68c29b1620f5a45a3f5 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Fri, 26 Apr 2019 23:09:05 +0100
Subject: [PATCH] Add bignum support

---
 Cargo.toml    | 1 +
 src/bignum.rs | 5 +++++
 src/lib.rs    | 3 +++
 3 files changed, 9 insertions(+)
 create mode 100644 src/bignum.rs

diff --git a/Cargo.toml b/Cargo.toml
index e80b73c..b68eff0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,3 +14,4 @@ wee_alloc = "0.4.4"
 default = [ "std" ]
 std = []
 debug = []
+bignum = []
diff --git a/src/bignum.rs b/src/bignum.rs
new file mode 100644
index 0000000..46a7885
--- /dev/null
+++ b/src/bignum.rs
@@ -0,0 +1,5 @@
+/// The bignum system library.
+extern "C" {
+    pub fn bignum_mul256(a: *const u32, b: *const u32, ret: *mut u32);
+    pub fn bignum_umulmod256(a: *const u32, b: *const u32, modulo: *const u32, ret: *mut u32);
+}
diff --git a/src/lib.rs b/src/lib.rs
index 3420c77..d1773fc 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,6 +29,9 @@ pub mod types;
 #[cfg(feature = "debug")]
 pub mod debug;
 
+#[cfg(feature = "bignum")]
+pub mod bignum;
+
 #[cfg(not(feature = "std"))]
 pub mod convert;