Merge #49: BIP375 (PR #45) Follow Up

b36df3a Apply feedback from PR #45 - reuse InvalidLengthError for InvalidDleqProof - remove new creator for DleqProof (macgyver13)

Pull request description:

  This PR addresses feedback received in PR #45.
  - reuse `InvalidLengthError` for `InvalidDleqProof`
  - remove `new` creator for `DleqProof`

  Also replace `actual_serde` with `serde`

ACKs for top commit:
  tcharding:
    ACK b36df3a

Tree-SHA512: fe07a51243e7c9a37747c2739811ef46595dec79f8735f96d40cec7f0b1594ac9e93ff90d5a55e767db4d9ba2c7a31cb389ee173b235f0a1a37e162c3619f58b

Author: tcharding

src/serialize.rs

@@ -24,6 +24,8 @@ use bitcoin::{
 use crate::error::write_err;
 use crate::prelude::*;
 use crate::sighash_type::PsbtSighashType;
+#[cfg(feature = "silent-payments")]
+use crate::v2::dleq;
 use crate::version;
 
 /// A trait for serializing a value as raw data for insertion into PSBT
@@ -428,12 +430,8 @@ pub enum Error {
         expected: usize,
     },
     /// Invalid DLEQ proof for BIP-375 silent payments (expected 64 bytes).
-    InvalidDleqProof {
-        /// The length that was provided.
-        got: usize,
-        /// The expected length.
-        expected: usize,
-    },
+    #[cfg(feature = "silent-payments")]
+    InvalidDleqProof(dleq::InvalidLengthError),
 }
 
 impl fmt::Display for Error {
@@ -467,8 +465,9 @@ impl fmt::Display for Error {
             InvalidEcdhShare { got, expected } => {
                 write!(f, "invalid ECDH share: got {} bytes, expected {}", got, expected)
             }
-            InvalidDleqProof { got, expected } => {
-                write!(f, "invalid DLEQ proof: got {} bytes, expected {}", got, expected)
+            #[cfg(feature = "silent-payments")]
+            InvalidDleqProof(e) => {
+                write!(f, "invalid DLEQ proof: got {} bytes, expected {}", e.got, e.expected)
             }
         }
     }
@@ -499,8 +498,9 @@ impl std::error::Error for Error {
             | TapTree(_)
             | PartialDataConsumption
             | InvalidScanKey { .. }
-            | InvalidEcdhShare { .. }
-            | InvalidDleqProof { .. } => None,
+            | InvalidEcdhShare { .. } => None,
+            #[cfg(feature = "silent-payments")]
+            InvalidDleqProof { .. } => None,
         }
     }
 }

src/v2/dleq.rs

@@ -14,10 +14,10 @@ use crate::serialize::{Deserialize, Serialize};
 pub struct DleqProof(pub [u8; 64]);
 
 #[cfg(feature = "serde")]
-impl actual_serde::Serialize for DleqProof {
+impl serde::Serialize for DleqProof {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
-        S: actual_serde::Serializer,
+        S: serde::Serializer,
     {
         if serializer.is_human_readable() {
             serializer.serialize_str(&bitcoin::hex::DisplayHex::to_lower_hex_string(&self.0[..]))
@@ -28,14 +28,14 @@ impl actual_serde::Serialize for DleqProof {
 }
 
 #[cfg(feature = "serde")]
-impl<'de> actual_serde::Deserialize<'de> for DleqProof {
+impl<'de> serde::Deserialize<'de> for DleqProof {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
-        D: actual_serde::Deserializer<'de>,
+        D: serde::Deserializer<'de>,
     {
         if deserializer.is_human_readable() {
             struct HexVisitor;
-            impl actual_serde::de::Visitor<'_> for HexVisitor {
+            impl serde::de::Visitor<'_> for HexVisitor {
                 type Value = DleqProof;
 
                 fn expecting(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
@@ -44,7 +44,7 @@ impl<'de> actual_serde::Deserialize<'de> for DleqProof {
 
                 fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
                 where
-                    E: actual_serde::de::Error,
+                    E: serde::de::Error,
                 {
                     use bitcoin::hex::FromHex;
                     let vec = Vec::<u8>::from_hex(s).map_err(E::custom)?;
@@ -56,7 +56,7 @@ impl<'de> actual_serde::Deserialize<'de> for DleqProof {
             deserializer.deserialize_str(HexVisitor)
         } else {
             struct BytesVisitor;
-            impl actual_serde::de::Visitor<'_> for BytesVisitor {
+            impl serde::de::Visitor<'_> for BytesVisitor {
                 type Value = DleqProof;
 
                 fn expecting(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
@@ -65,7 +65,7 @@ impl<'de> actual_serde::Deserialize<'de> for DleqProof {
 
                 fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
                 where
-                    E: actual_serde::de::Error,
+                    E: serde::de::Error,
                 {
                     DleqProof::try_from(v).map_err(|e| {
                         E::custom(format!("expected {} bytes, got {}", e.expected, e.got))
@@ -78,9 +78,6 @@ impl<'de> actual_serde::Deserialize<'de> for DleqProof {
 }
 
 impl DleqProof {
-    /// Creates a new [`DleqProof`] from a 64-byte array.
-    pub fn new(bytes: [u8; 64]) -> Self { DleqProof(bytes) }
-
     /// Returns the inner 64-byte array.
     pub fn as_bytes(&self) -> &[u8; 64] { &self.0 }
 }
@@ -115,9 +112,11 @@ impl Serialize for DleqProof {
 
 impl Deserialize for DleqProof {
     fn deserialize(bytes: &[u8]) -> Result<Self, crate::serialize::Error> {
-        DleqProof::try_from(bytes).map_err(|e| crate::serialize::Error::InvalidDleqProof {
-            got: e.got,
-            expected: e.expected,
+        DleqProof::try_from(bytes).map_err(|e| {
+            crate::serialize::Error::InvalidDleqProof(InvalidLengthError {
+                got: e.got,
+                expected: e.expected,
+            })
         })
     }
 }

tests/bip375-parse-invalid.rs

@@ -16,7 +16,7 @@ fn bip375_global_field_mismatch_dleq_only() {
     // Approach 1: Programmatic
     let mut psbt = Creator::new().psbt();
     let scan_key = CompressedPublicKey::from_slice(&[0x02u8; 33]).unwrap();
-    let dleq_proof = DleqProof::new([0xAAu8; 64]);
+    let dleq_proof = DleqProof::from([0xAAu8; 64]);
     psbt.global.sp_dleq_proofs.insert(scan_key, dleq_proof);
 
     let bytes = psbt.serialize();

tests/bip375-parse-valid.rs

@@ -21,7 +21,7 @@ fn valid_psbt_with_bip375_global_fields() -> Psbt {
         "02c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee5",
     )
     .unwrap();
-    let dleq_proof = DleqProof::new([0xAAu8; 64]);
+    let dleq_proof = DleqProof::from([0xAAu8; 64]);
 
     psbt.global.sp_ecdh_shares.insert(scan_key, ecdh_share);
     psbt.global.sp_dleq_proofs.insert(scan_key, dleq_proof);