examples: add OP_RETURN example

Author: benma's agent

Cargo.toml

@@ -75,6 +75,10 @@ required-features = ["usb", "tokio/rt", "tokio/macros"]
 name = "btc_sign_psbt"
 required-features = ["usb", "tokio/rt", "tokio/macros"]
 
+[[example]]
+name = "btc_sign_op_return"
+required-features = ["usb", "tokio/rt", "tokio/macros"]
+
 [[example]]
 name = "btc_sign_msg"
 required-features = ["usb", "tokio/rt", "tokio/macros"]

Makefile

@@ -10,6 +10,8 @@ example-btc-signtx:
 	cargo run --example btc_signtx --features=usb,tokio/rt,tokio/macros
 example-btc-psbt:
 	cargo run --example btc_sign_psbt --features=usb,tokio/rt,tokio/macros
+example-btc-sign-op-return:
+	cargo run --example btc_sign_op_return --features=usb,tokio/rt,tokio/macros
 example-btc-sign-msg:
 	cargo run --example btc_sign_msg --features=usb,tokio/rt,tokio/macros
 example-btc-miniscript:

examples/btc_sign_op_return.rs

@@ -0,0 +1,163 @@
+use std::str::FromStr;
+
+use bitbox_api::{pb, Keypath};
+
+use bitcoin::{
+    bip32::{ChildNumber, DerivationPath, Fingerprint, Xpub},
+    blockdata::script::Builder,
+    opcodes::all,
+    psbt::Psbt,
+    secp256k1, transaction, Amount, OutPoint, ScriptBuf, Sequence, Transaction, TxIn, TxOut,
+    Witness,
+};
+use semver::VersionReq;
+
+async fn connect_bitbox() -> bitbox_api::PairedBitBox<bitbox_api::runtime::TokioRuntime> {
+    let noise_config = Box::new(bitbox_api::NoiseConfigNoCache {});
+    let device = bitbox_api::BitBox::<bitbox_api::runtime::TokioRuntime>::from_hid_device(
+        bitbox_api::usb::get_any_bitbox02().unwrap(),
+        noise_config,
+    )
+    .await
+    .unwrap();
+    let pairing = device.unlock_and_pair().await.unwrap();
+    if let Some(pairing_code) = pairing.get_pairing_code().as_ref() {
+        println!("Pairing code\n{pairing_code}");
+    }
+    pairing.wait_confirm().await.unwrap()
+}
+
+async fn build_op_return_psbt(
+    paired: &bitbox_api::PairedBitBox<bitbox_api::runtime::TokioRuntime>,
+) -> Psbt {
+    let coin = pb::BtcCoin::Tbtc;
+    let secp = secp256k1::Secp256k1::new();
+
+    let fingerprint_hex = paired.root_fingerprint().await.unwrap();
+    let fingerprint = Fingerprint::from_str(&fingerprint_hex).unwrap();
+    let account_path: DerivationPath = "m/84'/1'/0'".parse().unwrap();
+    let input_path: DerivationPath = "m/84'/1'/0'/0/5".parse().unwrap();
+    let change_path: DerivationPath = "m/84'/1'/0'/1/0".parse().unwrap();
+
+    let account_keypath = Keypath::from(&account_path);
+    let account_xpub = paired
+        .btc_xpub(
+            coin,
+            &account_keypath,
+            pb::btc_pub_request::XPubType::Tpub,
+            false,
+        )
+        .await
+        .unwrap();
+
+    let account_xpub = Xpub::from_str(&account_xpub).unwrap();
+
+    let input_pub = account_xpub
+        .derive_pub(
+            &secp,
+            &[
+                ChildNumber::from_normal_idx(0).unwrap(),
+                ChildNumber::from_normal_idx(5).unwrap(),
+            ],
+        )
+        .unwrap()
+        .to_pub();
+    let change_pub = account_xpub
+        .derive_pub(
+            &secp,
+            &[
+                ChildNumber::from_normal_idx(1).unwrap(),
+                ChildNumber::from_normal_idx(0).unwrap(),
+            ],
+        )
+        .unwrap()
+        .to_pub();
+
+    let prev_tx = Transaction {
+        version: transaction::Version::TWO,
+        lock_time: bitcoin::absolute::LockTime::ZERO,
+        input: vec![TxIn {
+            previous_output: "3131313131313131313131313131313131313131313131313131313131313131:0"
+                .parse()
+                .unwrap(),
+            script_sig: ScriptBuf::new(),
+            sequence: Sequence(0xFFFFFFFF),
+            witness: Witness::default(),
+        }],
+        output: vec![TxOut {
+            value: Amount::from_sat(50_000_000),
+            script_pubkey: ScriptBuf::new_p2wpkh(&input_pub.wpubkey_hash()),
+        }],
+    };
+
+    let op_return_data = b"hello world";
+    let op_return_script = Builder::new()
+        .push_opcode(all::OP_RETURN)
+        .push_slice(op_return_data)
+        .into_script();
+
+    let tx = Transaction {
+        version: transaction::Version::TWO,
+        lock_time: bitcoin::absolute::LockTime::ZERO,
+        input: vec![TxIn {
+            previous_output: OutPoint {
+                txid: prev_tx.compute_txid(),
+                vout: 0,
+            },
+            script_sig: ScriptBuf::new(),
+            sequence: Sequence(0xFFFFFFFF),
+            witness: Witness::default(),
+        }],
+        output: vec![
+            TxOut {
+                value: Amount::from_sat(49_000_000),
+                script_pubkey: ScriptBuf::new_p2wpkh(&change_pub.wpubkey_hash()),
+            },
+            TxOut {
+                value: Amount::from_sat(0),
+                script_pubkey: op_return_script,
+            },
+        ],
+    };
+
+    let mut psbt = Psbt::from_unsigned_tx(tx).unwrap();
+    psbt.inputs[0].non_witness_utxo = Some(prev_tx.clone());
+    psbt.inputs[0].witness_utxo = Some(prev_tx.output[0].clone());
+    psbt.inputs[0]
+        .bip32_derivation
+        .insert(input_pub.0, (fingerprint, input_path.clone()));
+
+    psbt.outputs[0]
+        .bip32_derivation
+        .insert(change_pub.0, (fingerprint, change_path.clone()));
+
+    psbt
+}
+
+#[tokio::main(flavor = "current_thread")]
+async fn main() {
+    let paired = connect_bitbox().await;
+
+    let firmware_version = paired.version();
+    if !VersionReq::parse(">=9.24.0")
+        .unwrap()
+        .matches(firmware_version)
+    {
+        eprintln!(
+            "Connected firmware {firmware_version} does not support OP_RETURN outputs (requires >=9.24.0)."
+        );
+        return;
+    }
+
+    let mut psbt = build_op_return_psbt(&paired).await;
+
+    paired
+        .btc_sign_psbt(
+            pb::BtcCoin::Tbtc,
+            &mut psbt,
+            None,
+            pb::btc_sign_init_request::FormatUnit::Default,
+        )
+        .await
+        .unwrap();
+}