Re-org keys and ecdsa mods - pt.1

This commit tries to achieve separation of signature- and key-related types, previously mixed in a single ECDSA module.

Rationale: bitcoin key types are not specific for signature algorithm.

This is achieved through
- Remove key mod with its content moved to ecdsa mod
- Re-export keys under key module in util mod - to make git generate diff for the rename of ecdsa mod in the next commit correctly.

src/blockdata/script.rs

@@ -39,7 +39,7 @@ use policy::DUST_RELAY_TX_FEE;
 #[cfg(feature="bitcoinconsensus")] use core::convert::From;
 #[cfg(feature="bitcoinconsensus")] use OutPoint;
 
-use util::ecdsa::PublicKey;
+use util::key::PublicKey;
 use util::address::WitnessVersion;
 use util::taproot::{LeafVersion, TapBranchHash, TapLeafHash};
 use secp256k1::{Secp256k1, Verification};
@@ -1031,7 +1031,7 @@ mod test {
     use hashes::hex::{FromHex, ToHex};
     use consensus::encode::{deserialize, serialize};
     use blockdata::opcodes;
-    use util::ecdsa::PublicKey;
+    use util::key::PublicKey;
     use util::psbt::serialize::Serialize;
 
     #[test]

src/util/address.rs

@@ -20,13 +20,13 @@
 //! ```rust
 //! use bitcoin::network::constants::Network;
 //! use bitcoin::util::address::Address;
-//! use bitcoin::util::ecdsa;
+//! use bitcoin::PublicKey;
 //! use bitcoin::secp256k1::Secp256k1;
 //! use bitcoin::secp256k1::rand::thread_rng;
 //!
 //! // Generate random key pair.
 //! let s = Secp256k1::new();
-//! let public_key = ecdsa::PublicKey::new(s.generate_keypair(&mut thread_rng()).1);
+//! let public_key = PublicKey::new(s.generate_keypair(&mut thread_rng()).1);
 //!
 //! // Generate pay-to-pubkey-hash address.
 //! let address = Address::p2pkh(&public_key, Network::Bitcoin);
@@ -47,8 +47,8 @@ use blockdata::{script, opcodes};
 use blockdata::constants::{PUBKEY_ADDRESS_PREFIX_MAIN, SCRIPT_ADDRESS_PREFIX_MAIN, PUBKEY_ADDRESS_PREFIX_TEST, SCRIPT_ADDRESS_PREFIX_TEST, MAX_SCRIPT_ELEMENT_SIZE};
 use network::constants::Network;
 use util::base58;
-use util::ecdsa;
 use util::taproot::TapBranchHash;
+use util::key::PublicKey;
 use blockdata::script::Instruction;
 use util::schnorr::{TapTweak, UntweakedPublicKey, TweakedPublicKey};
 
@@ -408,7 +408,7 @@ impl Payload {
 
     /// Creates a pay to (compressed) public key hash payload from a public key
     #[inline]
-    pub fn p2pkh(pk: &ecdsa::PublicKey) -> Payload {
+    pub fn p2pkh(pk: &PublicKey) -> Payload {
         Payload::PubkeyHash(pk.pubkey_hash())
     }
 
@@ -422,15 +422,15 @@ impl Payload {
     }
 
     /// Create a witness pay to public key payload from a public key
-    pub fn p2wpkh(pk: &ecdsa::PublicKey) -> Result<Payload, Error> {
+    pub fn p2wpkh(pk: &PublicKey) -> Result<Payload, Error> {
         Ok(Payload::WitnessProgram {
             version: WitnessVersion::V0,
             program: pk.wpubkey_hash().ok_or(Error::UncompressedPubkey)?.to_vec(),
         })
     }
 
     /// Create a pay to script payload that embeds a witness pay to public key
-    pub fn p2shwpkh(pk: &ecdsa::PublicKey) -> Result<Payload, Error> {
+    pub fn p2shwpkh(pk: &PublicKey) -> Result<Payload, Error> {
         let builder = script::Builder::new()
             .push_int(0)
             .push_slice(&pk.wpubkey_hash().ok_or(Error::UncompressedPubkey)?);
@@ -543,7 +543,7 @@ impl Address {
     ///
     /// This is the preferred non-witness type address.
     #[inline]
-    pub fn p2pkh(pk: &ecdsa::PublicKey, network: Network) -> Address {
+    pub fn p2pkh(pk: &PublicKey, network: Network) -> Address {
         Address {
             network,
             payload: Payload::p2pkh(pk),
@@ -568,7 +568,7 @@ impl Address {
     ///
     /// # Errors
     /// Will only return an error if an uncompressed public key is provided.
-    pub fn p2wpkh(pk: &ecdsa::PublicKey, network: Network) -> Result<Address, Error> {
+    pub fn p2wpkh(pk: &PublicKey, network: Network) -> Result<Address, Error> {
         Ok(Address {
             network,
             payload: Payload::p2wpkh(pk)?,
@@ -581,7 +581,7 @@ impl Address {
     ///
     /// # Errors
     /// Will only return an Error if an uncompressed public key is provided.
-    pub fn p2shwpkh(pk: &ecdsa::PublicKey, network: Network) -> Result<Address, Error> {
+    pub fn p2shwpkh(pk: &PublicKey, network: Network) -> Result<Address, Error> {
         Ok(Address {
             network,
             payload: Payload::p2shwpkh(pk)?,
@@ -878,7 +878,7 @@ mod tests {
 
     use blockdata::script::Script;
     use network::constants::Network::{Bitcoin, Testnet};
-    use util::ecdsa::PublicKey;
+    use util::key::PublicKey;
     use secp256k1::XOnlyPublicKey;
 
     use super::*;

src/util/bip143.rs

@@ -194,7 +194,7 @@ mod tests {
     use consensus::encode::deserialize;
     use network::constants::Network;
     use util::address::Address;
-    use util::ecdsa::PublicKey;
+    use util::key::PublicKey;
     use hashes::hex::FromHex;
 
     use super::*;

src/util/bip32.rs

@@ -19,6 +19,7 @@
 
 use prelude::*;
 
+use io::Write;
 use core::{fmt, str::FromStr, default::Default};
 #[cfg(feature = "std")] use std::error;
 #[cfg(feature = "serde")] use serde;
@@ -28,9 +29,8 @@ use hashes::{sha512, Hash, HashEngine, Hmac, HmacEngine};
 use secp256k1::{self, Secp256k1, XOnlyPublicKey};
 
 use network::constants::Network;
-use util::{base58, endian};
-use util::{key, ecdsa, schnorr};
-use io::Write;
+use util::{base58, endian, key};
+use util::key::{PublicKey, PrivateKey, KeyPair};
 
 /// A chain code
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -528,8 +528,8 @@ impl ExtendedPrivKey {
     }
 
     /// Constructs ECDSA compressed private key matching internal secret key representation.
-    pub fn to_priv(&self) -> ecdsa::PrivateKey {
-        ecdsa::PrivateKey {
+    pub fn to_priv(&self) -> PrivateKey {
+        PrivateKey {
             compressed: true,
             network: self.network,
             inner: self.private_key
@@ -538,8 +538,8 @@ impl ExtendedPrivKey {
 
     /// Constructs BIP340 keypair for Schnorr signatures and Taproot use matching the internal
     /// secret key representation.
-    pub fn to_keypair<C: secp256k1::Signing>(&self, secp: &Secp256k1<C>) -> schnorr::KeyPair {
-        schnorr::KeyPair::from_seckey_slice(secp, &self.private_key[..]).expect("BIP32 internal private key representation is broken")
+    pub fn to_keypair<C: secp256k1::Signing>(&self, secp: &Secp256k1<C>) -> KeyPair {
+        KeyPair::from_seckey_slice(secp, &self.private_key[..]).expect("BIP32 internal private key representation is broken")
     }
 
     /// Attempts to derive an extended private key from a path.
@@ -660,8 +660,8 @@ impl ExtendedPubKey {
     }
 
     /// Constructs ECDSA compressed public key matching internal public key representation.
-    pub fn to_pub(&self) -> ecdsa::PublicKey {
-        ecdsa::PublicKey {
+    pub fn to_pub(&self) -> PublicKey {
+        PublicKey {
             compressed: true,
             inner: self.public_key
         }

src/util/ecdsa.rs

@@ -15,24 +15,70 @@
 //!
 //! This module provides ECDSA keys used in Bitcoin that can be roundtrip
 //! (de)serialized.
-//!
+
+pub use secp256k1::{XOnlyPublicKey, KeyPair};
 
 use prelude::*;
 
 use core::{ops, str::FromStr};
 use core::fmt::{self, Write as _fmtWrite};
 use io;
+#[cfg(feature = "std")] use std::error;
 
 use secp256k1::{self, Secp256k1};
 use network::constants::Network;
 use hashes::{Hash, hash160, hex};
 use hashes::hex::FromHex;
 use hash_types::{PubkeyHash, WPubkeyHash};
 use util::base58;
-use util::key::Error;
 use blockdata::transaction::{EcdsaSigHashType, NonStandardSigHashType};
 
 
+/// A key-related error.
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub enum Error {
+    /// Base58 encoding error
+    Base58(base58::Error),
+    /// secp256k1-related error
+    Secp256k1(secp256k1::Error),
+}
+
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Error::Base58(ref e) => write!(f, "Key base58 error: {}", e),
+            Error::Secp256k1(ref e) => write!(f, "Key secp256k1 error: {}", e),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl ::std::error::Error for Error {
+    fn cause(&self) -> Option<&dyn error::Error> {
+        match *self {
+            Error::Base58(ref e) => Some(e),
+            Error::Secp256k1(ref e) => Some(e),
+        }
+    }
+}
+
+#[doc(hidden)]
+impl From<base58::Error> for Error {
+    fn from(e: base58::Error) -> Error {
+        Error::Base58(e)
+    }
+}
+
+#[doc(hidden)]
+impl From<secp256k1::Error> for Error {
+    fn from(e: secp256k1::Error) -> Error {
+        Error::Secp256k1(e)
+    }
+}
+
+
 /// A Bitcoin ECDSA public key
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct PublicKey {

src/util/misc.rs

@@ -42,7 +42,7 @@ mod message_signing {
     use secp256k1;
     use secp256k1::ecdsa::{RecoveryId, RecoverableSignature};
 
-    use util::ecdsa::PublicKey;
+    use util::key::PublicKey;
     use util::address::{Address, AddressType};
 
     /// An error used for dealing with Bitcoin Signed Messages.

src/util/mod.rs

@@ -18,7 +18,6 @@
 //!
 
 pub mod ecdsa;
-pub mod key;
 pub mod schnorr;
 pub mod address;
 pub mod amount;
@@ -37,6 +36,14 @@ pub mod sighash;
 
 pub(crate) mod endian;
 
+pub mod key {
+    //! Bitcoin keys.
+    //!
+    //! This module provides keys used in Bitcoin that can be roundtrip (de)serialized.
+
+    pub use super::ecdsa::{XOnlyPublicKey, PublicKey, PrivateKey, KeyPair, Error};
+}
+
 use prelude::*;
 use io;
 use core::fmt;