From 4817b5cf672e1c9ec1a336a6c9c9b3fe867448b4 Mon Sep 17 00:00:00 2001
From: Jay Geng <jay@stellar.org>
Date: Wed, 23 Oct 2024 14:38:30 -0400
Subject: [PATCH] add bytesn conversion

---
 soroban-sdk/src/crypto/bls12_381.rs       |  8 ++++++++
 soroban-sdk/src/tests/crypto_bls12_381.rs | 12 +++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/soroban-sdk/src/crypto/bls12_381.rs b/soroban-sdk/src/crypto/bls12_381.rs
index 26338cee..ba66723a 100644
--- a/soroban-sdk/src/crypto/bls12_381.rs
+++ b/soroban-sdk/src/crypto/bls12_381.rs
@@ -198,6 +198,14 @@ impl Fr {
         &self.0
     }
 
+    pub fn from_bytes(bytes: BytesN<32>) -> Self {
+        U256::from_be_bytes(bytes.env(), bytes.as_ref()).into()
+    }
+
+    pub fn to_bytes(&self) -> BytesN<32> {
+        self.as_u256().to_be_bytes().try_into().unwrap_optimized()
+    }
+
     pub fn as_val(&self) -> &Val {
         self.0.as_val()
     }
diff --git a/soroban-sdk/src/tests/crypto_bls12_381.rs b/soroban-sdk/src/tests/crypto_bls12_381.rs
index 6b6761d0..a8efef6f 100644
--- a/soroban-sdk/src/tests/crypto_bls12_381.rs
+++ b/soroban-sdk/src/tests/crypto_bls12_381.rs
@@ -80,10 +80,16 @@ fn test_bls_g2() {
     let vp: Vec<G2Affine> = vec![&env, one.clone(), one.clone()];
     let vs: Vec<Fr> = vec![
         &env,
-        U256::from_u32(&env, 1).into(),
-        U256::from_u32(&env, 0).into(),
+        Fr::from_bytes(bytesn!(
+            &env,
+            0x0000000000000000000000000000000000000000000000000000000000000001
+        )),
+        Fr::from_bytes(bytesn!(
+            &env,
+            0x0000000000000000000000000000000000000000000000000000000000000000
+        )),
     ];
-    let res = bls12_381.g2_msm(vp, vs);
+    let res = bls12_381.g2_msm(vp.clone(), vs);
     assert_eq!(res, one);
 
     // map to curve (test case from https://datatracker.ietf.org/doc/html/rfc9380)