bitcoin/common: use bitcoin crate to compute pkscript

Remove our own code to improve clarity.

Author: benma

src/rust/bitbox02-rust/src/hww/api/bitcoin/common.rs

@@ -1,4 +1,4 @@
-// Copyright 2022-2024 Shift Crypto AG
+// Copyright 2022-2025 Shift Crypto AG
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -25,10 +25,11 @@ pub use pb::btc_sign_init_request::FormatUnit;
 pub use pb::{BtcCoin, BtcOutputType};
 
 use super::script_configs::{ValidatedScriptConfig, ValidatedScriptConfigWithKeypath};
-use super::{multisig, params::Params, script};
+use super::{multisig, params::Params};
 
 use sha2::{Digest, Sha256};
 
+use bitcoin::ScriptBuf;
 use bitcoin::bech32;
 use bitcoin::hashes::Hash;
 
@@ -254,51 +255,42 @@ impl Payload {
         }
     }
 
-    /// Computes the pkScript from a pubkey hash or script hash or pubkey, depending on the output type.
+    /// Computes the pkScript from a pubkey hash or script hash or pubkey, depending on the output
+    /// type.
     pub fn pk_script(&self, params: &Params) -> Result<Vec<u8>, Error> {
         let payload = self.data.as_slice();
-        match self.output_type {
-            BtcOutputType::Unknown => Err(Error::InvalidInput),
+        let script = match self.output_type {
+            BtcOutputType::Unknown => return Err(Error::InvalidInput),
             BtcOutputType::P2pkh => {
-                if payload.len() != HASH160_LEN {
-                    return Err(Error::Generic);
-                }
-                let mut result = vec![script::OP_DUP, script::OP_HASH160];
-                script::push_data(&mut result, payload);
-                result.extend_from_slice(&[script::OP_EQUALVERIFY, script::OP_CHECKSIG]);
-                Ok(result)
+                let pk_hash =
+                    bitcoin::PubkeyHash::from_slice(payload).map_err(|_| Error::Generic)?;
+
+                ScriptBuf::new_p2pkh(&pk_hash)
             }
             BtcOutputType::P2sh => {
-                if payload.len() != HASH160_LEN {
-                    return Err(Error::Generic);
-                }
-                let mut result = vec![script::OP_HASH160];
-                script::push_data(&mut result, payload);
-                result.push(script::OP_EQUAL);
-                Ok(result)
+                let script_hash =
+                    bitcoin::ScriptHash::from_slice(payload).map_err(|_| Error::Generic)?;
+                ScriptBuf::new_p2sh(&script_hash)
             }
-            BtcOutputType::P2wpkh | BtcOutputType::P2wsh => {
-                if (self.output_type == BtcOutputType::P2wpkh && payload.len() != HASH160_LEN)
-                    || (self.output_type == BtcOutputType::P2wsh && payload.len() != SHA256_LEN)
-                {
-                    return Err(Error::Generic);
-                }
-                let mut result = vec![script::OP_0];
-                script::push_data(&mut result, payload);
-                Ok(result)
+            BtcOutputType::P2wpkh => {
+                let wpkh = bitcoin::WPubkeyHash::from_slice(payload).map_err(|_| Error::Generic)?;
+                ScriptBuf::new_p2wpkh(&wpkh)
+            }
+            BtcOutputType::P2wsh => {
+                let wsh = bitcoin::WScriptHash::from_slice(payload).map_err(|_| Error::Generic)?;
+                ScriptBuf::new_p2wsh(&wsh)
             }
             BtcOutputType::P2tr => {
                 if !params.taproot_support {
                     return Err(Error::InvalidInput);
                 }
-                if payload.len() != 32 {
-                    return Err(Error::Generic);
-                }
-                let mut result = vec![script::OP_1];
-                script::push_data(&mut result, payload);
-                Ok(result)
+                let tweaked = bitcoin::key::TweakedPublicKey::dangerous_assume_tweaked(
+                    bitcoin::XOnlyPublicKey::from_slice(payload).map_err(|_| Error::Generic)?,
+                );
+                ScriptBuf::new_p2tr_tweaked(tweaked)
             }
-        }
+        };
+        Ok(script.into_bytes())
     }
 }
 

src/rust/bitbox02-rust/src/hww/api/bitcoin/script.rs

@@ -14,15 +14,6 @@
 
 use alloc::vec::Vec;
 
-// https://en.bitcoin.it/wiki/Script
-pub const OP_0: u8 = 0;
-pub const OP_1: u8 = 0x51;
-pub const OP_HASH160: u8 = 0xa9;
-pub const OP_DUP: u8 = 0x76;
-pub const OP_EQUALVERIFY: u8 = 0x88;
-pub const OP_CHECKSIG: u8 = 0xac;
-pub const OP_EQUAL: u8 = 0x87;
-
 /// Serialize a number in the VarInt encoding.
 /// https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer
 pub fn serialize_varint(value: u64) -> Vec<u8> {
@@ -45,12 +36,6 @@ pub fn serialize_varint(value: u64) -> Vec<u8> {
     out
 }
 
-/// Performs a data push onto `v`: the varint length of data followed by data.
-pub fn push_data(v: &mut Vec<u8>, data: &[u8]) {
-    v.extend_from_slice(&serialize_varint(data.len() as _));
-    v.extend_from_slice(data);
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -111,26 +96,4 @@ mod tests {
             b"\xff\xff\xff\xff\xff\xff\xff\xff\xff"
         );
     }
-
-    #[test]
-    fn test_push_data() {
-        assert_eq!(
-            {
-                let mut v = Vec::new();
-                push_data(&mut v, b"");
-                v
-            },
-            vec![0]
-        );
-
-        // Data with length 255.
-        assert_eq!(
-            {
-                let mut v = Vec::new();
-                push_data(&mut v, b"bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
-                v
-            },
-            b"\xfd\xff\x00bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb".to_vec(),
-        );
-    }
 }