Move InputPair to the receive module

payjoin-cli/src/app/mod.rs

@@ -7,8 +7,9 @@ use bitcoin::TxIn;
 use bitcoincore_rpc::bitcoin::Amount;
 use bitcoincore_rpc::RpcApi;
 use payjoin::bitcoin::psbt::Psbt;
+use payjoin::receive::InputPair;
 use payjoin::send::Sender;
-use payjoin::{bitcoin, InputPair, PjUri};
+use payjoin::{bitcoin, PjUri};
 
 pub mod config;
 use crate::app::config::AppConfig;

payjoin/src/lib.rs

@@ -48,6 +48,5 @@ mod uri;
 
 #[cfg(feature = "base64")]
 pub use bitcoin::base64;
-pub use psbt::InputPair;
 pub use uri::{PjParseError, PjUri, PjUriBuilder, Uri, UriExt};
 pub use url::{ParseError, Url};

payjoin/src/psbt.rs

@@ -106,49 +106,12 @@ fn redeem_script(script_sig: &Script) -> Option<&Script> {
 // https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#p2wpkh-nested-in-bip16-p2sh
 const NESTED_P2WPKH_MAX: InputWeightPrediction = InputWeightPrediction::from_slice(23, &[72, 33]);
 
-#[derive(Clone, Debug)]
-pub struct InputPair {
-    pub(crate) txin: TxIn,
-    pub(crate) psbtin: psbt::Input,
-}
-
-impl InputPair {
-    pub fn new(txin: TxIn, psbtin: psbt::Input) -> Result<Self, PsbtInputError> {
-        let input_pair = Self { txin, psbtin };
-        // TODO consider whether or not this should live in receive module since it's a baby of that state machine
-        let raw = InternalInputPair::from(&input_pair);
-        raw.validate_utxo(true)?;
-        let address_type = raw.address_type()?;
-        if address_type == AddressType::P2sh && input_pair.psbtin.redeem_script.is_none() {
-            return Err(PsbtInputError::NoRedeemScript);
-        }
-        Ok(input_pair)
-    }
-
-    pub(crate) fn address_type(&self) -> AddressType {
-        InternalInputPair::from(self)
-            .address_type()
-            .expect("address type should have been validated in InputPair::new")
-    }
-
-    pub(crate) fn previous_txout(&self) -> TxOut {
-        InternalInputPair::from(self)
-            .previous_txout()
-            .expect("UTXO information should have been validated in InputPair::new")
-            .clone()
-    }
-}
-
 #[derive(Clone, Debug)]
 pub(crate) struct InternalInputPair<'a> {
     pub txin: &'a TxIn,
     pub psbtin: &'a psbt::Input,
 }
 
-impl<'a> From<&'a InputPair> for InternalInputPair<'a> {
-    fn from(pair: &'a InputPair) -> Self { Self { psbtin: &pair.psbtin, txin: &pair.txin } }
-}
-
 impl<'a> InternalInputPair<'a> {
     /// Returns TxOut associated with the input
     pub fn previous_txout(&self) -> Result<&TxOut, PrevTxOutError> {

payjoin/src/receive/mod.rs

@@ -29,7 +29,7 @@ use std::cmp::{max, min};
 use bitcoin::base64::prelude::BASE64_STANDARD;
 use bitcoin::base64::Engine;
 use bitcoin::psbt::Psbt;
-use bitcoin::{Amount, FeeRate, OutPoint, Script, TxIn, TxOut, Weight};
+use bitcoin::{psbt, AddressType, Amount, FeeRate, OutPoint, Script, TxIn, TxOut, Weight};
 
 mod error;
 mod optional_parameters;
@@ -47,12 +47,50 @@ use error::{
 };
 use optional_parameters::Params;
 
-use crate::psbt::{InputPair, PsbtExt};
+use crate::psbt::{InternalInputPair, PsbtExt, PsbtInputError};
 
 pub trait Headers {
     fn get_header(&self, key: &str) -> Option<&str>;
 }
 
+/// Helper to construct a pair of (txin, psbtin) with some built-in validation
+/// Use with [`InputPair::new`] to contribute receiver inputs.
+#[derive(Clone, Debug)]
+pub struct InputPair {
+    pub(crate) txin: TxIn,
+    pub(crate) psbtin: psbt::Input,
+}
+
+impl InputPair {
+    pub fn new(txin: TxIn, psbtin: psbt::Input) -> Result<Self, PsbtInputError> {
+        let input_pair = Self { txin, psbtin };
+        let raw = InternalInputPair::from(&input_pair);
+        raw.validate_utxo(true)?;
+        let address_type = raw.address_type()?;
+        if address_type == AddressType::P2sh && input_pair.psbtin.redeem_script.is_none() {
+            return Err(PsbtInputError::NoRedeemScript);
+        }
+        Ok(input_pair)
+    }
+
+    pub(crate) fn address_type(&self) -> AddressType {
+        InternalInputPair::from(self)
+            .address_type()
+            .expect("address type should have been validated in InputPair::new")
+    }
+
+    pub(crate) fn previous_txout(&self) -> TxOut {
+        InternalInputPair::from(self)
+            .previous_txout()
+            .expect("UTXO information should have been validated in InputPair::new")
+            .clone()
+    }
+}
+
+impl<'a> From<&'a InputPair> for InternalInputPair<'a> {
+    fn from(pair: &'a InputPair) -> Self { Self { psbtin: &pair.psbtin, txin: &pair.txin } }
+}
+
 /// The sender's original PSBT and optional parameters
 ///
 /// This type is used to process the request. It is returned by

payjoin/src/receive/v2/mod.rs

@@ -16,8 +16,9 @@ use super::{
 };
 use crate::hpke::{decrypt_message_a, encrypt_message_b, HpkeKeyPair, HpkePublicKey};
 use crate::ohttp::{ohttp_decapsulate, ohttp_encapsulate, OhttpEncapsulationError, OhttpKeys};
-use crate::psbt::{InputPair, PsbtExt};
+use crate::psbt::PsbtExt;
 use crate::receive::optional_parameters::Params;
+use crate::receive::InputPair;
 use crate::{PjUriBuilder, Request};
 
 pub(crate) mod error;

payjoin/tests/integration.rs

@@ -12,8 +12,9 @@ mod integration {
     use bitcoind::bitcoincore_rpc::{self, RpcApi};
     use log::{log_enabled, Level};
     use once_cell::sync::{Lazy, OnceCell};
+    use payjoin::receive::InputPair;
     use payjoin::send::SenderBuilder;
-    use payjoin::{InputPair, PjUri, PjUriBuilder, Request, Uri};
+    use payjoin::{PjUri, PjUriBuilder, Request, Uri};
     use tracing_subscriber::{EnvFilter, FmtSubscriber};
     use url::Url;