Merge pull request rust-bitcoin#601 from LNP-BP/feat/bech32m-1

Bech32m adoption

Author: apoelstra

Cargo.toml

@@ -22,7 +22,7 @@ secp-lowmemory = ["secp256k1/lowmemory"]
 secp-recovery = ["secp256k1/recovery"]
 
 [dependencies]
-bech32 = "0.7.3"
+bech32 = "0.8.0"
 bitcoin_hashes = "0.9.6"
 secp256k1 = "0.20.2"
 

src/util/address.rs

@@ -398,14 +398,15 @@ impl fmt::Display for Address {
                     Network::Testnet | Network::Signet => "tb",
                     Network::Regtest => "bcrt",
                 };
+                let bech_ver = if ver.to_u8() > 0 {  bech32::Variant::Bech32m } else { bech32::Variant::Bech32 };
                 let mut upper_writer;
                 let writer = if fmt.alternate() {
                     upper_writer = UpperWriter(fmt);
                     &mut upper_writer as &mut dyn fmt::Write
                 } else {
                     fmt as &mut dyn fmt::Write
                 };
-                let mut bech32_writer = bech32::Bech32Writer::new(hrp, writer)?;
+                let mut bech32_writer = bech32::Bech32Writer::new(hrp, bech_ver, writer)?;
                 bech32::WriteBase32::write_u5(&mut bech32_writer, ver)?;
                 bech32::ToBase32::write_base32(&prog, &mut bech32_writer)
             }
@@ -448,7 +449,7 @@ impl FromStr for Address {
         };
         if let Some(network) = bech32_network {
             // decode as bech32
-            let (_, payload) = bech32::decode(s)?;
+            let (_, payload, variant) = bech32::decode(s)?;
             if payload.is_empty() {
                 return Err(Error::EmptyBech32Payload);
             }
@@ -472,6 +473,12 @@ impl FromStr for Address {
                 return Err(Error::InvalidSegwitV0ProgramLength(program.len()));
             }
 
+            // Bech32 encoding check
+            if (version.to_u8() > 0 && variant != bech32::Variant::Bech32m) ||
+               (version.to_u8() == 0 && variant != bech32::Variant::Bech32) {
+                return Err(Error::InvalidWitnessVersion(version.to_u8()))
+            }
+
             return Ok(Address {
                 payload: Payload::WitnessProgram {
                     version: version,
@@ -681,14 +688,17 @@ mod tests {
     }
 
     #[test]
-    fn test_bip173_vectors() {
+    fn test_bip173_350_vectors() {
+        // Test vectors valid under both BIP-173 and BIP-350
         let valid_vectors = [
             ("BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4", "0014751e76e8199196d454941c45d1b3a323f1433bd6"),
             ("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7", "00201863143c14c5166804bd19203356da136c985678cd4d27a1b8c6329604903262"),
-            ("bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7k7grplx", "5128751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6"),
-            ("BC1SW50QA3JX3S", "6002751e"),
-            ("bc1zw508d6qejxtdg4y5r3zarvaryvg6kdaj", "5210751e76e8199196d454941c45d1b3a323"),
+            ("bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kt5nd6y", "5128751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6"),
+            ("BC1SW50QGDZ25J", "6002751e"),
+            ("bc1zw508d6qejxtdg4y5r3zarvaryvaxxpcs", "5210751e76e8199196d454941c45d1b3a323"),
             ("tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy", "0020000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433"),
+            ("tb1pqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesf3hn0c", "5120000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433"),
+            ("bc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqzk5jj0", "512079be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798")
         ];
         for vector in &valid_vectors {
             let addr: Address = vector.0.parse().unwrap();
@@ -697,16 +707,59 @@ mod tests {
         }
 
         let invalid_vectors = [
+            // 1. BIP-350 test vectors
+            // Invalid human-readable part
+            "tc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vq5zuyut",
+            // Invalid checksums (Bech32 instead of Bech32m):
+            "bc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqh2y7hd",
+            "tb1z0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqglt7rf",
+            "BC1S0XLXVLHEMJA6C4DQV22UAPCTQUPFHLXM9H8Z3K2E72Q4K9HCZ7VQ54WELL",
+            "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kemeawh",
+            "tb1q0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vq24jc47",
+            // Invalid character in checksum
+            "bc1p38j9r5y49hruaue7wxjce0updqjuyyx0kh56v8s25huc6995vvpql3jow4",
+            // Invalid witness version
+            "BC130XLXVLHEMJA6C4DQV22UAPCTQUPFHLXM9H8Z3K2E72Q4K9HCZ7VQ7ZWS8R",
+            // Invalid program length (1 byte)
+            "bc1pw5dgrnzv",
+            // Invalid program length (41 bytes)
+            "bc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7v8n0nx0muaewav253zgeav",
+            // Invalid program length for witness version 0 (per BIP141)
+            "BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P",
+            // Mixed case
+            "tb1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vq47Zagq",
+            // zero padding of more than 4 bits
+            "bc1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7v07qwwzcrf",
+            // Non-zero padding in 8-to-5 conversion
+            "tb1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vpggkg4j",
+            // Empty data section
+            "bc1gmk9yu",
+
+            // 2. BIP-173 test vectors
+            // Invalid human-readable part
             "tc1qw508d6qejxtdg4y5r3zarvary0c5xw7kg3g4ty",
+            // Invalid checksum
             "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t5",
+            // Invalid witness version
             "BC13W508D6QEJXTDG4Y5R3ZARVARY0C5XW7KN40WF2",
+            // Invalid program length
             "bc1rw5uspcuh",
+            // Invalid program length
             "bc10w508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kw5rljs90",
+            // Invalid program length for witness version 0 (per BIP141)
             "BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P",
+            // Mixed case
             "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sL5k7",
+            // zero padding of more than 4 bits
             "bc1zw508d6qejxtdg4y5r3zarvaryvqyzf3du",
+            // Non-zero padding in 8-to-5 conversion
             "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3pjxtptv",
-            "bc1gmk9yu",
+            // Final test for empty data section is the same as above in BIP-350
+
+            // 3. BIP-173 valid test vectors obsolete by BIP-350
+            "bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7k7grplx",
+            "BC1SW50QA3JX3S",
+            "bc1zw508d6qejxtdg4y5r3zarvaryvg6kdaj",
         ];
         for vector in &invalid_vectors {
             assert!(vector.parse::<Address>().is_err());