Merge rust-bitcoin/rust-bitcoin#2497: Add the `FromScriptError` for handling errors in `address`

c2d658ac05 Add `P2shError` for handling errors related to P2sh (harshit933)
5182a8d7a8 Remove unused variants from `Address::Error` (harshit933)
05b24946eb Add the `FromScriptError` for handling errors in `address` (harshit933)

Pull request description:

  This commit adds the `FromScriptError` struct to handle the errors while generating address from any script. It includes :
  - Unrecognized script error.
  - Witness Program error.
  - Witness Version error.

ACKs for top commit:
  tcharding:
    ACK c2d658ac05
  apoelstra:
    ACK c2d658ac05

Tree-SHA512: 891eed787129aaf1b664cc16d325178d5d2f77cc41a0543a3d9d1a5af1b58188daece1f6a653bdc6b76b82db0490a39e9bba7fc090e3727d15ee9b8977733698

bitcoin/src/address/error.rs

@@ -13,14 +13,6 @@ use crate::{base58, Network};
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[non_exhaustive]
 pub enum Error {
-    /// A witness version construction error.
-    WitnessVersion(witness_version::TryFromError),
-    /// A witness program error.
-    WitnessProgram(witness_program::Error),
-    /// Address size more than 520 bytes is not allowed.
-    ExcessiveScriptSize,
-    /// Script is not a p2pkh, p2sh or witness program.
-    UnrecognizedScript,
     /// Address's network differs from required one.
     NetworkValidation {
         /// Network that was required.
@@ -37,10 +29,6 @@ impl fmt::Display for Error {
         use Error::*;
 
         match *self {
-            WitnessVersion(ref e) => write_err!(f, "witness version construction error"; e),
-            WitnessProgram(ref e) => write_err!(f, "witness program error"; e),
-            ExcessiveScriptSize => write!(f, "script size exceed 520 bytes"),
-            UnrecognizedScript => write!(f, "script is not a p2pkh, p2sh or witness program"),
             NetworkValidation { required, ref address } => {
                 write!(f, "address ")?;
                 fmt::Display::fmt(&address.0, f)?;
@@ -56,21 +44,85 @@ impl std::error::Error for Error {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         use Error::*;
 
-        match self {
-            WitnessVersion(e) => Some(e),
-            WitnessProgram(e) => Some(e),
-            UnknownHrp(e) => Some(e),
-            ExcessiveScriptSize | UnrecognizedScript | NetworkValidation { .. } => None,
+        match *self {
+            UnknownHrp(ref e) => Some(e),
+            NetworkValidation { .. } => None,
         }
     }
 }
 
-impl From<witness_version::TryFromError> for Error {
-    fn from(e: witness_version::TryFromError) -> Error { Error::WitnessVersion(e) }
+/// Error while generating address from script.
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum FromScriptError {
+    /// Script is not a p2pkh, p2sh or witness program.
+    UnrecognizedScript,
+    /// A witness program error.
+    WitnessProgram(witness_program::Error),
+    /// A witness version construction error.
+    WitnessVersion(witness_version::TryFromError),
 }
 
-impl From<witness_program::Error> for Error {
-    fn from(e: witness_program::Error) -> Error { Error::WitnessProgram(e) }
+impl fmt::Display for FromScriptError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use FromScriptError::*;
+
+        match *self {
+            WitnessVersion(ref e) => write_err!(f, "witness version construction error"; e),
+            WitnessProgram(ref e) => write_err!(f, "witness program error"; e),
+            UnrecognizedScript => write!(f, "script is not a p2pkh, p2sh or witness program"),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for FromScriptError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        use FromScriptError::*;
+
+        match *self {
+            UnrecognizedScript => None,
+            WitnessVersion(ref e) => Some(e),
+            WitnessProgram(ref e) => Some(e),
+        }
+    }
+}
+
+impl From<witness_program::Error> for FromScriptError {
+    fn from(e : witness_program::Error) -> Self { Self::WitnessProgram(e) }
+}
+
+impl From<witness_version::TryFromError> for FromScriptError {
+    fn from(e: witness_version::TryFromError) -> Self { Self::WitnessVersion(e) }
+}
+
+/// Error while generating address from a p2sh script.
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum P2shError {
+    /// Address size more than 520 bytes is not allowed.
+    ExcessiveScriptSize,
+}
+
+impl fmt::Display for P2shError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use P2shError::*;
+
+        match *self {
+            ExcessiveScriptSize => write!(f, "script size exceed 520 bytes"),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for P2shError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        use P2shError::*;
+
+        match self {
+            ExcessiveScriptSize => None,
+        }
+    }
 }
 
 /// Address type is either invalid or not supported in rust-bitcoin.

bitcoin/src/address/mod.rs

@@ -51,10 +51,11 @@ use crate::network::{Network, NetworkKind};
 use crate::prelude::*;
 use crate::taproot::TapNodeHash;
 
+use self::error::P2shError;
 #[rustfmt::skip]                // Keep public re-exports separate.
 #[doc(inline)]
 pub use self::{
-    error::{Error, ParseError, UnknownAddressTypeError, UnknownHrpError},
+    error::{Error, ParseError, UnknownAddressTypeError, UnknownHrpError, FromScriptError},
 };
 
 /// The different types of addresses.
@@ -373,9 +374,9 @@ impl Address {
     /// This address type was introduced with BIP16 and is the popular type to implement multi-sig
     /// these days.
     #[inline]
-    pub fn p2sh(script: &Script, network: impl Into<NetworkKind>) -> Result<Address, Error> {
+    pub fn p2sh(script: &Script, network: impl Into<NetworkKind>) -> Result<Address, P2shError> {
         if script.len() > MAX_SCRIPT_ELEMENT_SIZE {
-            return Err(Error::ExcessiveScriptSize);
+            return Err(P2shError::ExcessiveScriptSize);
         }
         let hash = script.script_hash();
         Ok(Address::p2sh_from_hash(hash, network))
@@ -503,7 +504,7 @@ impl Address {
     pub fn is_spend_standard(&self) -> bool { self.address_type().is_some() }
 
     /// Constructs an [`Address`] from an output script (`scriptPubkey`).
-    pub fn from_script(script: &Script, network: Network) -> Result<Address, Error> {
+    pub fn from_script(script: &Script, network: Network) -> Result<Address, FromScriptError> {
         if script.is_p2pkh() {
             let bytes = script.as_bytes()[3..23].try_into().expect("statically 20B long");
             let hash = PubkeyHash::from_byte_array(bytes);
@@ -519,7 +520,7 @@ impl Address {
             let program = WitnessProgram::new(version, &script.as_bytes()[2..])?;
             Ok(Address::from_witness_program(program, network))
         } else {
-            Err(Error::UnrecognizedScript)
+            Err(FromScriptError::UnrecognizedScript)
         }
     }
 
@@ -861,7 +862,7 @@ mod tests {
     #[test]
     fn test_p2sh_parse_for_large_script() {
         let script = ScriptBuf::from_hex("552103a765fc35b3f210b95223846b36ef62a4e53e34e2925270c2c7906b92c9f718eb2103c327511374246759ec8d0b89fa6c6b23b33e11f92c5bc155409d86de0c79180121038cae7406af1f12f4786d820a1466eec7bc5785a1b5e4a387eca6d797753ef6db2103252bfb9dcaab0cd00353f2ac328954d791270203d66c2be8b430f115f451b8a12103e79412d42372c55dd336f2eb6eb639ef9d74a22041ba79382c74da2338fe58ad21035049459a4ebc00e876a9eef02e72a3e70202d3d1f591fc0dd542f93f642021f82102016f682920d9723c61b27f562eb530c926c00106004798b6471e8c52c60ee02057ae12123122313123123ac1231231231231313123131231231231313212313213123123552103a765fc35b3f210b95223846b36ef62a4e53e34e2925270c2c7906b92c9f718eb2103c327511374246759ec8d0b89fa6c6b23b33e11f92c5bc155409d86de0c79180121038cae7406af1f12f4786d820a1466eec7bc5785a1b5e4a387eca6d797753ef6db2103252bfb9dcaab0cd00353f2ac328954d791270203d66c2be8b430f115f451b8a12103e79412d42372c55dd336f2eb6eb639ef9d74a22041ba79382c74da2338fe58ad21035049459a4ebc00e876a9eef02e72a3e70202d3d1f591fc0dd542f93f642021f82102016f682920d9723c61b27f562eb530c926c00106004798b6471e8c52c60ee02057ae12123122313123123ac1231231231231313123131231231231313212313213123123552103a765fc35b3f210b95223846b36ef62a4e53e34e2925270c2c7906b92c9f718eb2103c327511374246759ec8d0b89fa6c6b23b33e11f92c5bc155409d86de0c79180121038cae7406af1f12f4786d820a1466eec7bc5785a1b5e4a387eca6d797753ef6db2103252bfb9dcaab0cd00353f2ac328954d791270203d66c2be8b430f115f451b8a12103e79412d42372c55dd336f2eb6eb639ef9d74a22041ba79382c74da2338fe58ad21035049459a4ebc00e876a9eef02e72a3e70202d3d1f591fc0dd542f93f642021f82102016f682920d9723c61b27f562eb530c926c00106004798b6471e8c52c60ee02057ae12123122313123123ac1231231231231313123131231231231313212313213123123").unwrap();
-        assert_eq!(Address::p2sh(&script, NetworkKind::Test), Err(Error::ExcessiveScriptSize));
+        assert_eq!(Address::p2sh(&script, NetworkKind::Test), Err(P2shError::ExcessiveScriptSize));
     }
 
     #[test]
@@ -1236,13 +1237,13 @@ mod tests {
         .unwrap();
         let invalid_segwitv0_script =
             ScriptBuf::from_hex("001161458e330389cd0437ee9fe3641d70cc18").unwrap();
-        let expected = Err(Error::UnrecognizedScript);
+        let expected = Err(FromScriptError::UnrecognizedScript);
 
         assert_eq!(Address::from_script(&bad_p2wpkh, Network::Bitcoin), expected);
         assert_eq!(Address::from_script(&bad_p2wsh, Network::Bitcoin), expected);
         assert_eq!(
             Address::from_script(&invalid_segwitv0_script, Network::Bitcoin),
-            Err(Error::WitnessProgram(witness_program::Error::InvalidSegwitV0Length(17)))
+            Err(FromScriptError::WitnessProgram(witness_program::Error::InvalidSegwitV0Length(17)))
         );
     }