Improve PubkeyHash and WPubkeyHash

Improve the pubkey hash types by doing:

- Define the types in the `crypto::key` module
- Add From<&PublicKey> impl for `PubkeyHash`

Keep the current crate level re-export so this does not impact the
public API _if_ people are using the re-export but is still a breaking
change.

bitcoin/src/address.rs

@@ -44,8 +44,8 @@ use crate::blockdata::constants::{
 use crate::blockdata::script::witness_program::{self, WitnessProgram};
 use crate::blockdata::script::witness_version::{self, WitnessVersion};
 use crate::blockdata::script::{self, Script, ScriptBuf};
-use crate::crypto::key::{PublicKey, TapTweak, TweakedPublicKey, UntweakedPublicKey};
-use crate::hash_types::{PubkeyHash, ScriptHash};
+use crate::crypto::key::{PubkeyHash, PublicKey, TapTweak, TweakedPublicKey, UntweakedPublicKey};
+use crate::hash_types::ScriptHash;
 use crate::network::Network;
 use crate::prelude::*;
 use crate::taproot::TapNodeHash;

bitcoin/src/blockdata/script/owned.rs

@@ -10,8 +10,10 @@ use crate::blockdata::opcodes::{self};
 use crate::blockdata::script::witness_program::WitnessProgram;
 use crate::blockdata::script::witness_version::WitnessVersion;
 use crate::blockdata::script::{opcode_to_verify, Builder, Instruction, PushBytes, Script};
-use crate::hash_types::{PubkeyHash, ScriptHash, WPubkeyHash, WScriptHash};
-use crate::key::{PublicKey, TapTweak, TweakedPublicKey, UntweakedPublicKey};
+use crate::hash_types::{ScriptHash, WScriptHash};
+use crate::key::{
+    PubkeyHash, PublicKey, TapTweak, TweakedPublicKey, UntweakedPublicKey, WPubkeyHash,
+};
 use crate::prelude::*;
 use crate::taproot::TapNodeHash;
 

bitcoin/src/blockdata/script/tests.rs

@@ -8,8 +8,7 @@ use hex_lit::hex;
 use super::*;
 use crate::blockdata::opcodes;
 use crate::consensus::encode::{deserialize, serialize};
-use crate::crypto::key::{PublicKey, XOnlyPublicKey};
-use crate::hash_types::{PubkeyHash, WPubkeyHash};
+use crate::crypto::key::{PubkeyHash, PublicKey, WPubkeyHash, XOnlyPublicKey};
 
 #[test]
 #[rustfmt::skip]

bitcoin/src/crypto/key.rs

@@ -17,7 +17,6 @@ pub use secp256k1::rand;
 pub use secp256k1::{self, constants, KeyPair, Parity, Secp256k1, Verification, XOnlyPublicKey};
 
 use crate::crypto::ecdsa;
-use crate::hash_types::{PubkeyHash, WPubkeyHash};
 use crate::network::Network;
 use crate::prelude::*;
 use crate::taproot::{TapNodeHash, TapTweakHash};
@@ -299,10 +298,22 @@ impl FromStr for PublicKey {
     }
 }
 
+hashes::hash_newtype! {
+    /// A hash of a public key.
+    pub struct PubkeyHash(hash160::Hash);
+    /// SegWit version of a public key hash.
+    pub struct WPubkeyHash(hash160::Hash);
+}
+crate::hash_types::impl_asref_push_bytes!(PubkeyHash, WPubkeyHash);
+
 impl From<PublicKey> for PubkeyHash {
     fn from(key: PublicKey) -> PubkeyHash { key.pubkey_hash() }
 }
 
+impl From<&PublicKey> for PubkeyHash {
+    fn from(key: &PublicKey) -> PubkeyHash { key.pubkey_hash() }
+}
+
 /// A Bitcoin ECDSA private key
 #[derive(Copy, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "std", derive(Debug))]

bitcoin/src/hash_types.rs

@@ -46,7 +46,7 @@ macro_rules! impl_asref_push_bytes {
         )*
     };
 }
-
+pub(crate) use impl_asref_push_bytes;
 // newtypes module is solely here so we can rustfmt::skip.
 pub use newtypes::*;
 
@@ -69,12 +69,8 @@ mod newtypes {
         /// A bitcoin block hash.
         pub struct BlockHash(sha256d::Hash);
 
-        /// A hash of a public key.
-        pub struct PubkeyHash(hash160::Hash);
         /// A hash of Bitcoin Script bytecode.
         pub struct ScriptHash(hash160::Hash);
-        /// SegWit version of a public key hash.
-        pub struct WPubkeyHash(hash160::Hash);
         /// SegWit version of a Bitcoin Script bytecode hash.
         pub struct WScriptHash(sha256::Hash);
 
@@ -103,5 +99,5 @@ mod newtypes {
     impl_hashencode!(FilterHash);
     impl_hashencode!(FilterHeader);
 
-    impl_asref_push_bytes!(PubkeyHash, ScriptHash, WPubkeyHash, WScriptHash);
+    impl_asref_push_bytes!(ScriptHash, WScriptHash);
 }

bitcoin/src/lib.rs

@@ -141,11 +141,9 @@ pub use crate::blockdata::weight::Weight;
 pub use crate::blockdata::witness::{self, Witness};
 pub use crate::blockdata::{constants, opcodes};
 pub use crate::consensus::encode::VarInt;
-pub use crate::crypto::key::{self, PrivateKey, PublicKey};
+pub use crate::crypto::key::{self, PrivateKey, PubkeyHash, PublicKey, WPubkeyHash};
 pub use crate::crypto::{ecdsa, sighash};
-pub use crate::hash_types::{
-    BlockHash, PubkeyHash, ScriptHash, Txid, WPubkeyHash, WScriptHash, Wtxid,
-};
+pub use crate::hash_types::{BlockHash, ScriptHash, Txid, WScriptHash, Wtxid};
 pub use crate::merkle_tree::MerkleBlock;
 pub use crate::network::Network;
 pub use crate::pow::{CompactTarget, Target, Work};