From d3aaae6bc1125184d291f51d4e495a4fbf999fa9 Mon Sep 17 00:00:00 2001
From: Dr Maxim Orlovsky <orlovsky@lnp-bp.org>
Date: Wed, 11 Dec 2024 11:16:46 +0100
Subject: [PATCH] seals: add TxoSeal constructors

---
 consensus/src/tx.rs |  1 +
 seals/src/txout.rs  | 24 ++++++++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/consensus/src/tx.rs b/consensus/src/tx.rs
index 4be298cc..d3590734 100644
--- a/consensus/src/tx.rs
+++ b/consensus/src/tx.rs
@@ -36,6 +36,7 @@ use crate::{
 };
 
 #[derive(Wrapper, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, From)]
+#[wrapper(AsSlice)]
 #[derive(StrictType, StrictDumb, StrictEncode, StrictDecode)]
 #[strict_type(lib = LIB_NAME_BITCOIN)]
 #[cfg_attr(
diff --git a/seals/src/txout.rs b/seals/src/txout.rs
index aed66f6c..abd32847 100644
--- a/seals/src/txout.rs
+++ b/seals/src/txout.rs
@@ -28,8 +28,8 @@ use std::cmp::Ordering;
 
 use amplify::confinement::TinyOrdMap;
 use amplify::{ByteArray, Bytes, Bytes32};
-use bc::{Outpoint, Tx, Txid};
-use commit_verify::{mpc, CommitId, ReservedBytes, StrictHash};
+use bc::{Outpoint, Tx, Txid, Vout};
+use commit_verify::{mpc, CommitId, Digest, DigestExt, ReservedBytes, Sha256, StrictHash};
 use single_use_seals::{ClientSideWitness, PublishedWitness, SealWitness, SingleUseSeal};
 use strict_encoding::StrictDumb;
 
@@ -180,6 +180,26 @@ impl<D: dbc::Proof> Ord for TxoSeal<D> {
     }
 }
 
+impl<D: dbc::Proof> TxoSeal<D> {
+    pub fn vout_no_fallback(vout: Vout, noise_seed: impl AsRef<[u8]>) -> Self {
+        Self::no_fallback(Outpoint::new(Txid::from([0xFFu8; 32]), vout), noise_seed)
+    }
+
+    pub fn no_fallback(outpoint: Outpoint, noise_seed: impl AsRef<[u8]>) -> Self {
+        let mut engine = Sha256::new();
+        engine.input_raw(noise_seed.as_ref());
+        engine.input_raw(outpoint.txid.as_ref());
+        engine.input_raw(&outpoint.vout.to_u32().to_be_bytes());
+        let mut noise = [0xFFu8; 40];
+        noise[..32].copy_from_slice(&engine.finish());
+        Self {
+            primary: outpoint,
+            secondary: TxoSealExt::Noise(Noise(noise.into())),
+            _phantom: PhantomData,
+        }
+    }
+}
+
 impl<D: dbc::Proof> SingleUseSeal for TxoSeal<D> {
     type Message = Bytes32;
     type PubWitness = Tx;