Implement getpubkey

README.md

@@ -45,7 +45,7 @@ API documentation is available [here](https://bitchan.github.io/bitmessage/docs/
   - [x] error
   - [x] object
 - [ ] Object types
-  - [ ] getpubkey
+  - [x] getpubkey
   - [ ] pubkey
   - [ ] msg
   - [ ] broadcast
@@ -55,7 +55,6 @@ API documentation is available [here](https://bitchan.github.io/bitmessage/docs/
   - [ ] Address
     - [x] encode
     - [x] decode
-    - [x] getRipe
     - [x] fromRandom
     - [ ] fromPassphrase
   - [x] UserAgent

lib/address.js

@@ -46,6 +46,10 @@ function Address(opts) {
  * @return {Address} Decoded address object.
  */
 Address.decode = function(str) {
+  if (str instanceof Address) {
+    return str;
+  }
+
   str = str.trim();
   if (str.slice(0, 3) === "BM-") {
     str = str.slice(3);
@@ -121,6 +125,21 @@ Address.prototype.getRipe = function(opts) {
   }
 };
 
+/**
+ * Calculate the address tag.
+ * @return {Buffer} A 32-byte address tag.
+ */
+Address.prototype.getTag = function() {
+  var ripe = this.getRipe();
+  var dataToHash = Buffer.concat([
+    var_int.encode(this.version),
+    var_int.encode(this.stream),
+    ripe,
+  ]);
+  var hash = bmcrypto.sha512(bmcrypto.sha512(dataToHash));
+  return hash.slice(32);
+};
+
 // Get truncated ripe hash length.
 function getripelen(ripe) {
   var zeroes = 0;

lib/messages.js

@@ -5,6 +5,7 @@
  * @see {@link https://bitmessage.org/Bitmessage%20Technical%20Paper.pdf}
  * @module bitmessage/messages
  */
+// TODO(Kagami): Document object-like params.
 
 "use strict";
 
@@ -266,8 +267,8 @@ var error = exports.error = {
  * a stream. It is the only message which propagates; all others are
  * only between two nodes.  
  * NOTE: You shouldn't use `encode` and `decode` methods directly.
- * Instead, get type of the object and encode/decode it with appropriate
- * function from `objects` module.
+ * Instead, get type of the object and process it using appropriate
+ * namespace from `objects` module.
  * @see {@link https://bitmessage.org/wiki/Protocol_specification#object}
  * @namespace
  */
@@ -285,20 +286,21 @@ exports.object = {
    * @return {?number} Object type.
    */
   getType: function(buf) {
-    // Per v3 spec object starts with nonce (8 bytes), expiresTime (8
-    // bytes) and objectType (4 bytes). So we need only first 20 bytes
-    // to read the type.
-    if (buf.length >= 20) {
+    assert(buf.length >= 22, "object message payload is too small");
     return buf.readUInt32BE(16, true);
-    }
   },
 
   /**
    * Decode `object` message payload.
-   * NOTE: `nonce` is copied, `payload` references input buffer.
+   * NOTE: `nonce` and `payload` are copied.
    * @param {Buffer} buf - Message payload
    * @return {Object} Decoded `object` structure.
    */
+  // FIXME(Kagami): Check for POW.
+  // TODO(Kagami): Option to not fail on bad POW (may be useful for
+  // bitchan).
+  // TODO(Kagami): Option to not fail on expired object (would be useful
+  // for bitchan).
   decode: function(buf) {
     // 8 + 8 + 4 + (1+) + (1+)
     assert(buf.length >= 22, "object message payload is too small");
@@ -311,13 +313,15 @@ exports.object = {
     var type = buf.readUInt32BE(16, true);
     var decodedVersion = structs.var_int.decode(buf.slice(20));
     var decodedStream = structs.var_int.decode(decodedVersion.rest);
+    var payload = new Buffer(decodedStream.rest.length);
+    decodedStream.rest.copy(payload);
     return {
       nonce: nonce,
       ttl: ttl,
       type: type,
       version: decodedVersion.value,
       stream: decodedStream.value,
-      payload: decodedStream.rest,
+      payload: payload,
     };
   },
 
@@ -326,6 +330,7 @@ exports.object = {
    * @param {Object} opts - Object options
    * @return {Buffer} Encoded payload.
    */
+  // TODO(Kagami): Do a POW if nonce is not provided.
   encode: function(opts) {
     assert(opts.nonce.length === 8, "Bad nonce");
     assert(opts.ttl > 0, "Bad TTL");

lib/objects.js

@@ -1,5 +1,68 @@
 /**
  * Working with objects.
+ * NOTE: All operations with objects in this module are asynchronous and
+ * return promises.
  * @see {@link https://bitmessage.org/wiki/Protocol_specification#Object_types}
  * @module bitmessage/objects
  */
+// TODO(Kagami): Document object-like params.
+
+"use strict";
+
+var objectAssign = Object.assign || require("object-assign");
+var assert = require("./util").assert;
+var promise = require("./platform").promise;
+var object = require("./messages").object;
+var Address = require("./address");
+
+/**
+ * `getpubkey` object. When a node has the hash of a public key (from an
+ * address) but not the public key itself, it must send out a request
+ * for the public key.
+ * @see {@link https://bitmessage.org/wiki/Protocol_specification#getpubkey}
+ * @namespace
+ */
+exports.getpubkey = {
+  /**
+   * Decode `getpubkey` object message payload.
+   * @param {Buffer} buf - Message payload
+   * @return {Promise.<Object>} A promise that contained decoded
+   * `object` structure when fulfilled.
+   */
+  decodeAsync: function(buf) {
+    return new promise(function(resolve) {
+      var decoded = object.decode(buf);
+      assert(decoded.type === object.GETPUBKEY, "Wrong object type");
+      var payload = decoded.payload;
+      delete decoded.payload;
+      if (decoded.version < 4) {
+        assert(payload.length === 20, "getpubkey ripe is too small");
+        // Payload is copied so it's safe to return it right away.
+        decoded.ripe = payload;
+      } else {
+        assert(payload.length === 32, "getpubkey tag is too small");
+        // Payload is copied so it's safe to return it right away.
+        decoded.tag = payload;
+      }
+      resolve(decoded);
+    });
+  },
+
+  /**
+   * Encode `getpubkey` object message payload.
+   * @param {Object} opts - `getpubkey` object options
+   * @return {Promise.<Buffer>} A promise that contained encoded message
+   * payload when fulfilled.
+   */
+  encodeAsync: function(opts) {
+    return new promise(function(resolve) {
+      opts = objectAssign({}, opts);
+      opts.type = object.GETPUBKEY;
+      var addr = Address.decode(opts.to);
+      opts.version = addr.version;
+      opts.stream = addr.stream;
+      opts.payload = opts.version < 4 ? addr.getRipe() : addr.getTag();
+      resolve(object.encode(opts));
+    });
+  },
+};

lib/structs.js

@@ -3,7 +3,7 @@
  * @see {@link https://bitmessage.org/wiki/Protocol_specification#Common_structures}
  * @module bitmessage/structs
  */
-// TODO(Kagami): Find a way how to document object params properly.
+// TODO(Kagami): Document object-like params.
 
 "use strict";
 

test.js

@@ -22,6 +22,8 @@ var addr = messages.addr;
 var inv = messages.inv;
 var error = messages.error;
 var object = messages.object;
+var objects = bitmessage.objects;
+var getpubkey = objects.getpubkey;
 var WIF = bitmessage.WIF;
 var POW = bitmessage.POW;
 var Address = bitmessage.Address;
@@ -414,6 +416,24 @@ describe("Message types", function() {
   });
 });
 
+describe("Object types", function() {
+  describe("getpubkey", function() {
+    it("should encode and decode", function() {
+      return getpubkey.encodeAsync({
+        nonce: Buffer(8),
+        ttl: 100,
+        to: "2cTux3PGRqHTEH6wyUP2sWeT4LrsGgy63z",
+      }).then(getpubkey.decodeAsync)
+      .then(function(res) {
+        expect(res.ttl).to.equal(100);
+        expect(res.version).to.equal(4);
+        expect(res.stream).to.equal(1);
+        expect(res.tag.toString("hex")).to.equal("facf1e3e6c74916203b7f714ca100d4d60604f0917696d0f09330f82f52bed1a");
+      });
+    });
+  });
+});
+
 describe("WIF", function() {
   var wifSign = "5JgQ79vTBusc61xYPtUEHYQ38AXKdDZgQ5rFp7Cbb4ZjXUKFZEV";
   var wifEnc = "5K2aL8cnsEWHwHfHnUrPo8QdYyRfoYUBmhAnWY5GTpDLbeyusnE";
@@ -521,6 +541,17 @@ describe("High-level classes", function() {
       expect(addr2.ripe[0]).to.equal(0);
     });
 
+    it("should calculate tag", function() {
+      var addr = Address.decode("2cTux3PGRqHTEH6wyUP2sWeT4LrsGgy63z");
+      expect(addr.getTag().toString("hex")).to.equal("facf1e3e6c74916203b7f714ca100d4d60604f0917696d0f09330f82f52bed1a");
+    });
+
+    it("should allow to decode Address instance", function() {
+      var addr = Address.decode("2cTux3PGRqHTEH6wyUP2sWeT4LrsGgy63z");
+      expect(addr.ripe.toString("hex")).to.equal("003ab6655de4bd8c603eba9b00dd5970725fdd56");
+      expect(Address.decode(addr)).to.equal(addr);
+    });
+
     // FIXME(Kagami): Don't run it in browser currently because it's
     // very slow. This need to be fixed.
     if (allTests && typeof window === "undefined") {