add from/toBech32

Author: dcousens

package.json

@@ -51,6 +51,7 @@
     "src"
   ],
   "dependencies": {
+    "bech32": "0.0.3",
     "bigi": "^1.4.0",
     "bip66": "^1.1.0",
     "bitcoin-ops": "^1.3.0",

src/address.js

@@ -1,4 +1,5 @@
 var Buffer = require('safe-buffer').Buffer
+var bech32 = require('bech32')
 var bs58check = require('bs58check')
 var bscript = require('./script')
 var networks = require('./networks')
@@ -16,6 +17,28 @@ function fromBase58Check (address) {
   return { hash: hash, version: version }
 }
 
+function fromBech32 (address, expectedPrefix) {
+  var result = bech32.decode(address)
+  var prefix = result.prefix
+  var words = result.words
+  if (expectedPrefix !== undefined) {
+    if (prefix !== expectedPrefix) throw new Error('Expected ' + expectedPrefix + ', got ' + prefix)
+  }
+
+  var version = words[0]
+  if (version > 16) throw new Error('Invalid version (' + version + ')')
+  var program = bech32.fromWords(words.slice(1))
+
+  if (version === 0) {
+    if (program.length !== 20 && program.length !== 32) throw new Error('Unknown program')
+  } else {
+    if (program.length < 2) throw new Error('Program too short')
+    if (program.length > 40) throw new Error('Program too long')
+  }
+
+  return { version, prefix, program: Buffer.from(program) }
+}
+
 function toBase58Check (hash, version) {
   typeforce(types.tuple(types.Hash160bit, types.UInt8), arguments)
 
@@ -26,6 +49,21 @@ function toBase58Check (hash, version) {
   return bs58check.encode(payload)
 }
 
+function toBech32 (prefix, version, program) {
+  if (version > 16) throw new Error('Invalid version (' + version + ')')
+  if (version === 0) {
+    if (program.length !== 20 && program.length !== 32) throw new Error('Unknown program')
+  } else {
+    if (program.length < 2) throw new Error('Program too short')
+    if (program.length > 40) throw new Error('Program too long')
+  }
+
+  var words = bech32.toWords(program)
+  words.unshift(version)
+
+  return bech32.encode(prefix, words)
+}
+
 function fromOutputScript (outputScript, network) {
   network = network || networks.bitcoin
 
@@ -47,7 +85,9 @@ function toOutputScript (address, network) {
 
 module.exports = {
   fromBase58Check: fromBase58Check,
+  fromBech32: fromBech32,
   fromOutputScript: fromOutputScript,
   toBase58Check: toBase58Check,
+  toBech32: toBech32,
   toOutputScript: toOutputScript
 }

test/address.js

@@ -8,7 +8,7 @@ var fixtures = require('./fixtures/address.json')
 
 describe('address', function () {
   describe('fromBase58Check', function () {
-    fixtures.valid.forEach(function (f) {
+    fixtures.standard.forEach(function (f) {
       it('decodes ' + f.base58check, function () {
         var decode = baddress.fromBase58Check(f.base58check)
 
@@ -26,8 +26,30 @@ describe('address', function () {
     })
   })
 
+  describe('fromBech32', function () {
+    fixtures.bech32.forEach((f) => {
+      it('encodes ' + f.address, function () {
+        var actual = baddress.fromBech32(f.address)
+
+        assert.strictEqual(actual.prefix, f.prefix)
+        assert.strictEqual(actual.program.toString('hex'), f.program)
+        assert.strictEqual(actual.version, f.version)
+      })
+    })
+
+    fixtures.invalid.bech32.forEach((f, i) => {
+      if (f.address === undefined) return
+
+      it('decode fails for ' + f.address + '(' + f.exception + ')', function () {
+        assert.throws(function () {
+          baddress.fromBech32(f.address, f.prefix)
+        }, new RegExp(f.exception))
+      })
+    })
+  })
+
   describe('fromOutputScript', function () {
-    fixtures.valid.forEach(function (f) {
+    fixtures.standard.forEach(function (f) {
       it('parses ' + f.script.slice(0, 30) + '... (' + f.network + ')', function () {
         var script = bscript.fromASM(f.script)
         var address = baddress.fromOutputScript(script, networks[f.network])
@@ -48,7 +70,7 @@ describe('address', function () {
   })
 
   describe('toBase58Check', function () {
-    fixtures.valid.forEach(function (f) {
+    fixtures.standard.forEach(function (f) {
       it('formats ' + f.hash + ' (' + f.network + ')', function () {
         var address = baddress.toBase58Check(Buffer.from(f.hash, 'hex'), f.version)
 
@@ -57,8 +79,30 @@ describe('address', function () {
     })
   })
 
+  describe('toBech32', function () {
+    fixtures.bech32.forEach((f, i) => {
+      // unlike the reference impl., we don't support mixed/uppercase
+      var string = f.address.toLowerCase()
+      var program = Buffer.from(f.program, 'hex')
+
+      it('encode ' + string, function () {
+        assert.deepEqual(baddress.toBech32(f.prefix, f.version, program), string)
+      })
+    })
+
+    fixtures.invalid.bech32.forEach((f, i) => {
+      if (!f.prefix || f.version === undefined || f.program === undefined) return
+
+      it('encode fails (' + f.exception, function () {
+        assert.throws(function () {
+          baddress.toBech32(f.prefix, f.version, Buffer.from(f.program, 'hex'))
+        }, new RegExp(f.exception))
+      })
+    })
+  })
+
   describe('toOutputScript', function () {
-    fixtures.valid.forEach(function (f) {
+    fixtures.standard.forEach(function (f) {
       var network = networks[f.network]
 
       it('exports ' + f.script.slice(0, 30) + '... (' + f.network + ')', function () {

test/fixtures/address.json

@@ -1,5 +1,5 @@
 {
-  "valid": [
+  "standard": [
     {
       "network": "bitcoin",
       "version": 0,
@@ -43,7 +43,96 @@
       "script": "OP_HASH160 cd7b44d0b03f2d026d1e586d7ae18903b0d385f6 OP_EQUAL"
     }
   ],
+  "bech32": [
+    {
+      "address": "BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4",
+      "prefix": "bc",
+      "program": "751e76e8199196d454941c45d1b3a323f1433bd6",
+      "version": 0
+    },
+    {
+      "address": "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7",
+      "prefix": "tb",
+      "program": "1863143c14c5166804bd19203356da136c985678cd4d27a1b8c6329604903262",
+      "version": 0
+    },
+    {
+      "address": "bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7k7grplx",
+      "prefix": "bc",
+      "program": "751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd6",
+      "version": 1
+    },
+    {
+      "address": "BC1SW50QA3JX3S",
+      "prefix": "bc",
+      "program": "751e",
+      "version": 16
+    },
+    {
+      "address": "bc1zw508d6qejxtdg4y5r3zarvaryvg6kdaj",
+      "prefix": "bc",
+      "program": "751e76e8199196d454941c45d1b3a323",
+      "version": 2
+    },
+    {
+      "address": "tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy",
+      "prefix": "tb",
+      "program": "000000c4a5cad46221b2a187905e5266362b99d5e91c6ce24d165dab93e86433",
+      "version": 0
+    }
+  ],
   "invalid": {
+    "bech32": [
+      {
+        "address": "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t5",
+        "exception": "Invalid checksum"
+      },
+      {
+        "address": "BC13W508D6QEJXTDG4Y5R3ZARVARY0C5XW7KN40WF2",
+        "prefix": "bc",
+        "version": 17,
+        "program": "751e76e8199196d454941c45d1b3a323f1433bd6",
+        "exception": "Invalid version \\(17\\)"
+      },
+      {
+        "address": "BC1SW50QA3JX3S",
+        "prefix": "foo",
+        "exception": "Expected foo, got bc"
+      },
+      {
+        "address": "bc1rw5uspcuh",
+        "prefix": "bc",
+        "version": 1,
+        "program": "75",
+        "exception": "Program too short"
+      },
+      {
+        "address": "bc10w508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kw5rljs90",
+        "prefix": "bc",
+        "version": 1,
+        "program": "751e76e8199196d454941c45d1b3a323f1433bd6751e76e8199196d454941c45d1b3a323f1433bd675",
+        "exception": "Program too long"
+      },
+      {
+        "address": "BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P",
+        "prefix": "bc",
+        "version": 0,
+        "program": "1d1e76e8199196d454941c45d1b3a323",
+        "exception": "Unknown program"
+      },
+      {
+        "address": "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sL5k7",
+        "exception": "Mixed-case string"
+      },
+      {
+        "address": "tb1pw508d6qejxtdg4y5r3zarqfsj6c3",
+        "exception": "Excess padding"
+      },
+      {
+        "address": "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3pjxtptv",
+        "exception": "Non-zero padding"
+      }
+    ],
     "fromBase58Check": [
       {
         "address": "7SeEnXWPaCCALbVrTnszCVGfRU8cGfx",