Use the new bech32 iterator API

Use the new bech32 iterator API that Andrew and I wrote.

Cargo-minimal.lock

@@ -16,9 +16,9 @@ checksum = "414dcefbc63d77c526a76b3afcf6fbb9b5e2791c19c3aa2297733208750c6e53"
 
 [[package]]
 name = "bech32"
-version = "0.9.0"
+version = "0.10.0-alpha"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5738be7561b0eeb501ef1d5c5db3f24e01ceb55fededd9b00039aada34966ad"
+checksum = "81cc1dec4c25e5a78c52802eda8e2adf0d2aca57ffc536326b75c0e531ea0a9b"
 
 [[package]]
 name = "bincode"

Cargo-recent.lock

@@ -16,9 +16,9 @@ checksum = "414dcefbc63d77c526a76b3afcf6fbb9b5e2791c19c3aa2297733208750c6e53"
 
 [[package]]
 name = "bech32"
-version = "0.9.1"
+version = "0.10.0-alpha"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d86b93f97252c47b41663388e6d155714a9d0c398b99f1005cbc5f978b29f445"
+checksum = "81cc1dec4c25e5a78c52802eda8e2adf0d2aca57ffc536326b75c0e531ea0a9b"
 
 [[package]]
 name = "bincode"

bitcoin/Cargo.toml

@@ -27,7 +27,7 @@ bitcoinconsensus-std = ["bitcoinconsensus/std", "std"]
 # Instead no-std enables additional features required for this crate to be usable without std.
 # As a result, both can be enabled without conflict.
 std = ["secp256k1/std", "hashes/std", "bech32/std", "internals/std", "hex/std"]
-no-std = ["core2", "hashes/alloc", "hashes/core2", "secp256k1/alloc", "hex/alloc", "hex/core2"]
+no-std = ["core2", "hashes/alloc", "hashes/core2", "bech32/alloc", "secp256k1/alloc", "hex/alloc", "hex/core2"]
 
 [package.metadata.docs.rs]
 all-features = true
@@ -36,7 +36,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 [dependencies]
 internals = { package = "bitcoin-internals", version = "0.2.0" }
 hex = { package = "hex-conservative", version = "0.1.1", default-features = false }
-bech32 = { version = "0.9.0", default-features = false }
+bech32 = { version = "0.10.0-alpha", default-features = false }
 hashes = { package = "bitcoin_hashes", version = "0.13.0", default-features = false }
 secp256k1 = { version = "0.27.0", default-features = false, features = ["bitcoin_hashes"] }
 hex_lit = "0.1.1"

bitcoin/src/address/error.rs

@@ -99,8 +99,8 @@ impl_std_error!(UnknownAddressTypeError);
 pub enum ParseError {
     /// Base58 error.
     Base58(base58::Error),
-    /// Bech32 error.
-    Bech32(bech32::Error),
+    /// Bech32 segwit decoding error.
+    Bech32(bech32::primitives::decode::SegwitHrpstringError),
     /// The bech32 payload was empty.
     EmptyBech32Payload,
     /// The wrong checksum algorithm was used. See BIP-0350.
@@ -122,7 +122,7 @@ impl fmt::Display for ParseError {
 
         match *self {
             Base58(ref e) => write_err!(f, "base58 error"; e),
-            Bech32(ref e) => write_err!(f, "bech32 error"; e),
+            Bech32(ref e) => write_err!(f, "bech32 segwit decoding error"; e),
             EmptyBech32Payload => write!(f, "the bech32 payload was empty"),
             InvalidBech32Variant { expected, found } => write!(
                 f,
@@ -154,8 +154,8 @@ impl From<base58::Error> for ParseError {
     fn from(e: base58::Error) -> Self { Self::Base58(e) }
 }
 
-impl From<bech32::Error> for ParseError {
-    fn from(e: bech32::Error) -> Self { Self::Bech32(e) }
+impl From<bech32::primitives::decode::SegwitHrpstringError> for ParseError {
+    fn from(e: bech32::primitives::decode::SegwitHrpstringError) -> Self { Self::Bech32(e) }
 }
 
 impl From<witness_version::TryFromError> for ParseError {

bitcoin/src/address/mod.rs

@@ -31,7 +31,7 @@ use core::fmt;
 use core::marker::PhantomData;
 use core::str::FromStr;
 
-use bech32;
+use bech32::primitives::hrp::{self, Hrp};
 use hashes::{sha256, Hash, HashEngine};
 use secp256k1::{Secp256k1, Verification, XOnlyPublicKey};
 
@@ -46,6 +46,7 @@ use crate::blockdata::script::{self, Script, ScriptBuf, ScriptHash};
 use crate::crypto::key::{PubkeyHash, PublicKey, TapTweak, TweakedPublicKey, UntweakedPublicKey};
 use crate::network::Network;
 use crate::prelude::*;
+use crate::script::PushBytesBuf;
 use crate::taproot::TapNodeHash;
 
 /// Error code for the address module.
@@ -237,8 +238,8 @@ pub struct AddressEncoding<'a> {
     pub p2pkh_prefix: u8,
     /// base58 version byte for p2sh payloads (e.g. 0x05 for "3..." addresses).
     pub p2sh_prefix: u8,
-    /// hrp used in bech32 addresss (e.g. "bc" for "bc1..." addresses).
-    pub bech32_hrp: &'a str,
+    /// The bech32 human-readable part.
+    pub hrp: Hrp,
 }
 
 /// Formats bech32 as upper case if alternate formatting is chosen (`{:#}`).
@@ -257,19 +258,16 @@ impl<'a> fmt::Display for AddressEncoding<'a> {
                 prefixed[1..].copy_from_slice(&hash[..]);
                 base58::encode_check_to_fmt(fmt, &prefixed[..])
             }
-            Payload::WitnessProgram(witness_prog) => {
-                let (version, prog) = (witness_prog.version(), witness_prog.program());
-                let mut upper_writer;
-                let writer = if fmt.alternate() {
-                    upper_writer = UpperWriter(fmt);
-                    &mut upper_writer as &mut dyn fmt::Write
+            Payload::WitnessProgram(witness_program) => {
+                let hrp = &self.hrp;
+                let version = witness_program.version().to_fe();
+                let program = witness_program.program().as_bytes();
+
+                if fmt.alternate() {
+                    bech32::segwit::encode_to_fmt_unchecked_uppercase(fmt, hrp, version, program)
                 } else {
-                    fmt as &mut dyn fmt::Write
-                };
-                let mut bech32_writer =
-                    bech32::Bech32Writer::new(self.bech32_hrp, version.bech32_variant(), writer)?;
-                bech32::WriteBase32::write_u5(&mut bech32_writer, version.into())?;
-                bech32::ToBase32::write_base32(&prog.as_bytes(), &mut bech32_writer)
+                    bech32::segwit::encode_to_fmt_unchecked(fmt, hrp, version, program)
+                }
             }
         }
     }
@@ -495,13 +493,12 @@ impl<V: NetworkValidation> Address<V> {
             Network::Bitcoin => SCRIPT_ADDRESS_PREFIX_MAIN,
             Network::Testnet | Network::Signet | Network::Regtest => SCRIPT_ADDRESS_PREFIX_TEST,
         };
-        let bech32_hrp = match self.network() {
-            Network::Bitcoin => "bc",
-            Network::Testnet | Network::Signet => "tb",
-            Network::Regtest => "bcrt",
+        let hrp = match self.network() {
+            Network::Bitcoin => hrp::BC,
+            Network::Testnet | Network::Signet => hrp::TB,
+            Network::Regtest => hrp::BCRT,
         };
-        let encoding =
-            AddressEncoding { payload: self.payload(), p2pkh_prefix, p2sh_prefix, bech32_hrp };
+        let encoding = AddressEncoding { payload: self.payload(), p2pkh_prefix, p2sh_prefix, hrp };
 
         use fmt::Display;
 
@@ -775,17 +772,6 @@ impl<V: NetworkValidation> fmt::Debug for Address<V> {
     }
 }
 
-struct UpperWriter<W: fmt::Write>(W);
-
-impl<W: fmt::Write> fmt::Write for UpperWriter<W> {
-    fn write_str(&mut self, s: &str) -> fmt::Result {
-        for c in s.chars() {
-            self.0.write_char(c.to_ascii_uppercase())?;
-        }
-        Ok(())
-    }
-}
-
 /// Extracts the bech32 prefix.
 ///
 /// # Returns
@@ -812,26 +798,11 @@ impl FromStr for Address<NetworkUnchecked> {
             _ => None,
         };
         if let Some(network) = bech32_network {
-            // decode as bech32
-            let (_, payload, variant) = bech32::decode(s)?;
-            if payload.is_empty() {
-                return Err(ParseError::EmptyBech32Payload);
-            }
-
-            // Get the script version and program (converted from 5-bit to 8-bit)
-            let (version, program): (WitnessVersion, Vec<u8>) = {
-                let (v, p5) = payload.split_at(1);
-                (WitnessVersion::try_from(v[0])?, bech32::FromBase32::from_base32(p5)?)
-            };
-
+            let (_hrp, version, data) = bech32::segwit::decode(s)?;
+            let version = WitnessVersion::try_from(version).expect("we know this is in range 0-16");
+            let program = PushBytesBuf::try_from(data).expect("decode() guarantees valid length");
             let witness_program = WitnessProgram::new(version, program)?;
 
-            // Encoding check
-            let expected = version.bech32_variant();
-            if expected != variant {
-                return Err(ParseError::InvalidBech32Variant { expected, found: variant });
-            }
-
             return Ok(Address::new(network, Payload::WitnessProgram(witness_program)));
         }
 

bitcoin/src/blockdata/script/witness_version.rs

@@ -11,6 +11,7 @@ use core::convert::TryFrom;
 use core::fmt;
 use core::str::FromStr;
 
+use bech32::Fe32;
 use internals::write_err;
 
 use crate::blockdata::opcodes::all::*;
@@ -72,12 +73,9 @@ impl WitnessVersion {
     /// into a byte since the conversion requires context (bitcoin script or just a version number).
     pub fn to_num(self) -> u8 { self as u8 }
 
-    /// Determines the checksum variant. See BIP-0350 for specification.
-    pub fn bech32_variant(&self) -> bech32::Variant {
-        match self {
-            WitnessVersion::V0 => bech32::Variant::Bech32,
-            _ => bech32::Variant::Bech32m,
-        }
+    /// Converts this witness version to a GF32 field element.
+    pub fn to_fe(self) -> Fe32 {
+        Fe32::try_from(self.to_num()).expect("0-16 are valid fe32 values")
     }
 }
 
@@ -95,10 +93,10 @@ impl FromStr for WitnessVersion {
     }
 }
 
-impl TryFrom<bech32::u5> for WitnessVersion {
+impl TryFrom<bech32::Fe32> for WitnessVersion {
     type Error = TryFromError;
 
-    fn try_from(value: bech32::u5) -> Result<Self, Self::Error> { Self::try_from(value.to_u8()) }
+    fn try_from(value: Fe32) -> Result<Self, Self::Error> { Self::try_from(value.to_u8()) }
 }
 
 impl TryFrom<u8> for WitnessVersion {
@@ -155,10 +153,8 @@ impl<'a> TryFrom<Instruction<'a>> for WitnessVersion {
     }
 }
 
-impl From<WitnessVersion> for bech32::u5 {
-    fn from(version: WitnessVersion) -> Self {
-        bech32::u5::try_from_u8(version.to_num()).expect("WitnessVersion must be 0..=16")
-    }
+impl From<WitnessVersion> for Fe32 {
+    fn from(version: WitnessVersion) -> Self { version.to_fe() }
 }
 
 impl From<WitnessVersion> for Opcode {