Support address de/serialization from/to future bech32m outputs

src/address.js

@@ -4,9 +4,31 @@ const networks = require('./networks');
 const payments = require('./payments');
 const bscript = require('./script');
 const types = require('./types');
-const { bech32 } = require('bech32');
+const { bech32, bech32m } = require('bech32');
 const bs58check = require('bs58check');
 const typeforce = require('typeforce');
+const FUTURE_SEGWIT_MAX_SIZE = 40;
+const FUTURE_SEGWIT_MIN_SIZE = 2;
+const FUTURE_SEGWIT_MAX_VERSION = 16;
+const FUTURE_SEGWIT_MIN_VERSION = 1;
+const FUTURE_SEGWIT_VERSION_DIFF = 0x50;
+function _toFutureSegwitAddress(output, network) {
+  const data = output.slice(2);
+  if (
+    data.length < FUTURE_SEGWIT_MIN_SIZE ||
+    data.length > FUTURE_SEGWIT_MAX_SIZE
+  )
+    throw new TypeError('Invalid program length for segwit address');
+  const version = output[0] - FUTURE_SEGWIT_VERSION_DIFF;
+  if (
+    version < FUTURE_SEGWIT_MIN_VERSION ||
+    version > FUTURE_SEGWIT_MAX_VERSION
+  )
+    throw new TypeError('Invalid version for segwit address');
+  if (output[1] !== data.length)
+    throw new TypeError('Invalid script for segwit address');
+  return toBech32(data, version, network.bech32);
+}
 function fromBase58Check(address) {
   const payload = bs58check.decode(address);
   // TODO: 4.0.0, move to "toOutputScript"
@@ -18,10 +40,22 @@ function fromBase58Check(address) {
 }
 exports.fromBase58Check = fromBase58Check;
 function fromBech32(address) {
-  const result = bech32.decode(address);
+  let result;
+  let version;
+  try {
+    result = bech32.decode(address);
+  } catch (e) {}
+  if (result) {
+    version = result.words[0];
+    if (version !== 0) throw new TypeError(address + ' uses wrong encoding');
+  } else {
+    result = bech32m.decode(address);
+    version = result.words[0];
+    if (version === 0) throw new TypeError(address + ' uses wrong encoding');
+  }
   const data = bech32.fromWords(result.words.slice(1));
   return {
-    version: result.words[0],
+    version,
     prefix: result.prefix,
     data: Buffer.from(data),
   };
@@ -38,7 +72,9 @@ exports.toBase58Check = toBase58Check;
 function toBech32(data, version, prefix) {
   const words = bech32.toWords(data);
   words.unshift(version);
-  return bech32.encode(prefix, words);
+  return version === 0
+    ? bech32.encode(prefix, words)
+    : bech32m.encode(prefix, words);
 }
 exports.toBech32 = toBech32;
 function fromOutputScript(output, network) {
@@ -56,6 +92,9 @@ function fromOutputScript(output, network) {
   try {
     return payments.p2wsh({ output, network }).address;
   } catch (e) {}
+  try {
+    return _toFutureSegwitAddress(output, network);
+  } catch (e) {}
   throw new Error(bscript.toASM(output) + ' has no matching Address');
 }
 exports.fromOutputScript = fromOutputScript;
@@ -83,7 +122,16 @@ function toOutputScript(address, network) {
           return payments.p2wpkh({ hash: decodeBech32.data }).output;
         if (decodeBech32.data.length === 32)
           return payments.p2wsh({ hash: decodeBech32.data }).output;
-      }
+      } else if (
+        decodeBech32.version >= FUTURE_SEGWIT_MIN_VERSION &&
+        decodeBech32.version <= FUTURE_SEGWIT_MAX_VERSION &&
+        decodeBech32.data.length >= FUTURE_SEGWIT_MIN_SIZE &&
+        decodeBech32.data.length <= FUTURE_SEGWIT_MAX_SIZE
+      )
+        return bscript.compile([
+          decodeBech32.version + FUTURE_SEGWIT_VERSION_DIFF,
+          decodeBech32.data,
+        ]);
     }
   }
   throw new Error(address + ' has no matching Script');

ts_src/address.ts

@@ -4,7 +4,7 @@ import * as payments from './payments';
 import * as bscript from './script';
 import * as types from './types';
 
-const { bech32 } = require('bech32');
+const { bech32, bech32m } = require('bech32');
 const bs58check = require('bs58check');
 const typeforce = require('typeforce');
 
@@ -19,6 +19,35 @@ export interface Bech32Result {
   data: Buffer;
 }
 
+const FUTURE_SEGWIT_MAX_SIZE: number = 40;
+const FUTURE_SEGWIT_MIN_SIZE: number = 2;
+const FUTURE_SEGWIT_MAX_VERSION: number = 16;
+const FUTURE_SEGWIT_MIN_VERSION: number = 1;
+const FUTURE_SEGWIT_VERSION_DIFF: number = 0x50;
+
+function _toFutureSegwitAddress(output: Buffer, network: Network): string {
+  const data = output.slice(2);
+
+  if (
+    data.length < FUTURE_SEGWIT_MIN_SIZE ||
+    data.length > FUTURE_SEGWIT_MAX_SIZE
+  )
+    throw new TypeError('Invalid program length for segwit address');
+
+  const version = output[0] - FUTURE_SEGWIT_VERSION_DIFF;
+
+  if (
+    version < FUTURE_SEGWIT_MIN_VERSION ||
+    version > FUTURE_SEGWIT_MAX_VERSION
+  )
+    throw new TypeError('Invalid version for segwit address');
+
+  if (output[1] !== data.length)
+    throw new TypeError('Invalid script for segwit address');
+
+  return toBech32(data, version, network.bech32);
+}
+
 export function fromBase58Check(address: string): Base58CheckResult {
   const payload = bs58check.decode(address);
 
@@ -33,11 +62,25 @@ export function fromBase58Check(address: string): Base58CheckResult {
 }
 
 export function fromBech32(address: string): Bech32Result {
-  const result = bech32.decode(address);
+  let result;
+  let version;
+  try {
+    result = bech32.decode(address);
+  } catch (e) {}
+
+  if (result) {
+    version = result.words[0];
+    if (version !== 0) throw new TypeError(address + ' uses wrong encoding');
+  } else {
+    result = bech32m.decode(address);
+    version = result.words[0];
+    if (version === 0) throw new TypeError(address + ' uses wrong encoding');
+  }
+
   const data = bech32.fromWords(result.words.slice(1));
 
   return {
-    version: result.words[0],
+    version,
     prefix: result.prefix,
     data: Buffer.from(data),
   };
@@ -61,7 +104,9 @@ export function toBech32(
   const words = bech32.toWords(data);
   words.unshift(version);
 
-  return bech32.encode(prefix, words);
+  return version === 0
+    ? bech32.encode(prefix, words)
+    : bech32m.encode(prefix, words);
 }
 
 export function fromOutputScript(output: Buffer, network?: Network): string {
@@ -80,6 +125,9 @@ export function fromOutputScript(output: Buffer, network?: Network): string {
   try {
     return payments.p2wsh({ output, network }).address as string;
   } catch (e) {}
+  try {
+    return _toFutureSegwitAddress(output, network);
+  } catch (e) {}
 
   throw new Error(bscript.toASM(output) + ' has no matching Address');
 }
@@ -111,7 +159,16 @@ export function toOutputScript(address: string, network?: Network): Buffer {
           return payments.p2wpkh({ hash: decodeBech32.data }).output as Buffer;
         if (decodeBech32.data.length === 32)
           return payments.p2wsh({ hash: decodeBech32.data }).output as Buffer;
-      }
+      } else if (
+        decodeBech32.version >= FUTURE_SEGWIT_MIN_VERSION &&
+        decodeBech32.version <= FUTURE_SEGWIT_MAX_VERSION &&
+        decodeBech32.data.length >= FUTURE_SEGWIT_MIN_SIZE &&
+        decodeBech32.data.length <= FUTURE_SEGWIT_MAX_SIZE
+      )
+        return bscript.compile([
+          decodeBech32.version + FUTURE_SEGWIT_VERSION_DIFF,
+          decodeBech32.data,
+        ]);
     }
   }