/**
* Working with objects.
* NOTE: Most 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.
// FIXME(Kagami): Think through the API, we may want to get decoded
// structure even if it contains unsupported version. Also error
// handling may need some refactoring.
"use strict";
var objectAssign = Object.assign || require("object-assign");
var bufferEqual = require("buffer-equal");
var assert = require("./_util").assert;
var promise = require("./platform").promise;
var bmcrypto = require("./crypto");
var Address = require("./address");
var structs = require("./structs");
var POW = require("./pow");
var util = require("./_util");
var var_int = structs.var_int;
var PubkeyBitfield = structs.PubkeyBitfield;
var message = structs.message;
var object = structs.object;
/**
* Try to get type of the given encoded object message.
* Note that this function doesn't do any validation because it is
* already provided by
* [object.decode]{@link module:bitmessage/structs.object.decode}
* routine. Normally you call this for each incoming object message and
* then call decode function of the appropriate object handler.
* @param {Buffer} buf - Buffer that starts with encoded object message
* @return {?number} Object's type if any.
*/
exports.getType = function(buf) {
// Message header: 4 + 12 + 4 + 4
// Object header: 8 + 8 + 4
if (buf.length < 44) {
return;
}
return buf.readUInt32BE(40, true);
};
/**
* Try to get type of the given object message payload.
* Note that this function doesn't do any validation because it is
* already provided by
* [object.decodePayload]{@link module:bitmessage/structs.object.decodePayload}
* routine. Normally you call this for each incoming object message
* payload and then call decode function of the appropriate object
* handler.
* @param {Buffer} buf - Buffer that starts with object message payload
* @return {?number} Object's type if any.
*/
exports.getPayloadType = function(buf) {
// Object header: 8 + 8 + 4
if (buf.length < 20) {
return;
}
return buf.readUInt32BE(16, true);
};
// Prepend nonce to a given object without nonce.
function prependNonce(obj, opts) {
return new promise(function(resolve) {
assert(obj.length <= 262136, "object message payload is too big");
opts = objectAssign({}, opts);
var nonce, target, powp;
if (opts.skipPow) {
nonce = new Buffer(8);
nonce.fill(0);
resolve(Buffer.concat([nonce, obj]));
} else {
opts.payloadLength = obj.length + 8; // Compensate for nonce
target = POW.getTarget(opts);
powp = POW.doAsync({target: target, data: obj})
.then(function(nonce) {
// TODO(Kagami): We may want to receive nonce as a Buffer from
// POW module to skip conversion step.
var payload = new Buffer(opts.payloadLength);
util.writeUInt64BE(payload, nonce, 0, true);
obj.copy(payload, 8);
return payload;
});
resolve(powp);
}
});
}
/**
* `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
* @static
*/
var getpubkey = exports.getpubkey = {
/**
* Decode `getpubkey` object message.
* @param {Buffer} buf - Message
* @param {?Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded
* `getpubkey` object structure when fulfilled.
*/
decodeAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = message.decode(buf);
assert(decoded.command === "object", "Bad command");
resolve(getpubkey.decodePayloadAsync(decoded.payload, opts));
});
},
/**
* Decode `getpubkey` object message payload.
* @param {Buffer} buf - Message payload
* @param {?Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded
* `getpubkey` object structure when fulfilled.
*/
decodePayloadAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = object.decodePayload(buf, opts);
assert(decoded.type === object.GETPUBKEY, "Wrong object type");
assert(decoded.version >= 2, "getpubkey version is too low");
assert(decoded.version <= 4, "getpubkey version is too high");
var objectPayload = util.popkey(decoded, "objectPayload");
if (decoded.version < 4) {
assert(objectPayload.length === 20, "getpubkey ripe is too small");
// Object payload is copied so it's safe to return it right away.
decoded.ripe = objectPayload;
} else {
assert(objectPayload.length === 32, "getpubkey tag is too small");
// Object payload is copied so it's safe to return it right away.
decoded.tag = objectPayload;
}
resolve(decoded);
});
},
/**
* Encode `getpubkey` object message.
* @param {Object} opts - `getpubkey` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* when fulfilled.
*/
encodeAsync: function(opts) {
return getpubkey.encodePayloadAsync(opts).then(function(payload) {
return message.encode("object", payload);
});
},
/**
* Encode `getpubkey` object message payload.
* @param {Object} opts - `getpubkey` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* payload when fulfilled.
*/
encodePayloadAsync: function(opts) {
return new promise(function(resolve) {
opts = objectAssign({}, opts);
opts.type = object.GETPUBKEY;
// Bitmessage address of recepeint of `getpubkey` message.
var to = Address.decode(opts.to);
assert(to.version >= 2, "Address version is too low");
assert(to.version <= 4, "Address version is too high");
opts.version = to.version;
opts.stream = to.stream;
opts.objectPayload = to.version < 4 ? to.ripe : to.getTag();
var obj = object.encodePayloadWithoutNonce(opts);
resolve(prependNonce(obj, opts));
});
},
};
// Extract pubkey data from decrypted object payload.
function extractPubkey(buf) {
var decoded = {length: 132};
// We assume here that input buffer was copied before so it's safe to
// return reference to it.
decoded.behavior = PubkeyBitfield(buf.slice(0, 4));
var signPublicKey = decoded.signPublicKey = new Buffer(65);
signPublicKey[0] = 4;
buf.copy(signPublicKey, 1, 4, 68);
var encPublicKey = decoded.encPublicKey = new Buffer(65);
encPublicKey[0] = 4;
buf.copy(encPublicKey, 1, 68, 132);
return decoded;
}
// Extract pubkey version 3 data from decrypted object payload.
function extractPubkeyV3(buf) {
var decoded = extractPubkey(buf);
var decodedTrials = var_int.decode(buf.slice(132));
decoded.nonceTrialsPerByte = decodedTrials.value;
decoded.length += decodedTrials.length;
var decodedExtraBytes = var_int.decode(decodedTrials.rest);
decoded.payloadLengthExtraBytes = decodedExtraBytes.value;
decoded.length += decodedExtraBytes.length;
var decodedSigLength = var_int.decode(decodedExtraBytes.rest);
var siglen = decodedSigLength.value;
var rest = decodedSigLength.rest;
assert(rest.length >= siglen, "Bad pubkey object payload length");
decoded.signature = rest.slice(0, siglen);
siglen += decodedSigLength.length;
decoded._siglen = siglen; // Internal value
decoded.length += siglen;
return decoded;
}
// Note that tag matching only works for address version >= 4.
function findAddrByTag(addrs, tag) {
var i, addr;
addrs = addrs || [];
if (Address.isAddress(addrs)) {
addrs = [addrs];
}
if (Array.isArray(addrs)) {
for (i = 0; i < addrs.length; i++) {
addr = addrs[i];
if (addr.version >= 4 && bufferEqual(addr.getTag(), tag)) {
return addr;
}
}
} else {
addr = addrs[tag];
if (addr && addr.version >= 4) {
return addr;
}
}
}
/**
* `pubkey` object.
* @see {@link https://bitmessage.org/wiki/Protocol_specification#pubkey}
* @namespace
* @static
*/
var pubkey = exports.pubkey = {
/**
* Decode `pubkey` object message.
* @param {Buffer} buf - Message
* @param {?Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded `pubkey`
* object structure when fulfilled.
*/
decodeAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = message.decode(buf);
assert(decoded.command === "object", "Bad command");
resolve(pubkey.decodePayloadAsync(decoded.payload, opts));
});
},
/**
* Decode `pubkey` object message payload.
* @param {Buffer} buf - Message payload
* @param {?Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded `pubkey`
* object structure when fulfilled.
*/
decodePayloadAsync: function(buf, opts) {
return new promise(function(resolve) {
opts = opts || {};
var decoded = object.decodePayload(buf, opts);
assert(decoded.type === object.PUBKEY, "Wrong object type");
var version = decoded.version;
assert(version >= 2, "Address version is too low");
assert(version <= 4, "Address version is too high");
var objectPayload = util.popkey(decoded, "objectPayload");
var siglen, pos, sig, dataToVerify, pubkeyp;
var tag, addr, pubkeyPrivateKey, dataToDecrypt;
// v2 pubkey.
if (version === 2) {
// 4 + 64 + 64
assert(
objectPayload.length === 132,
"Bad pubkey v2 object payload length");
objectAssign(decoded, extractPubkey(objectPayload));
return resolve(decoded);
}
// v3 pubkey.
if (version === 3) {
// 4 + 64 + 64 + (1+) + (1+) + (1+)
assert(
objectPayload.length >= 135,
"Bad pubkey v3 object payload length");
objectAssign(decoded, extractPubkeyV3(objectPayload));
siglen = util.popkey(decoded, "_siglen");
pos = decoded.headerLength + decoded.length - siglen;
// Object message payload from `expiresTime` up to `sig_length`.
dataToVerify = buf.slice(8, pos);
sig = decoded.signature;
pubkeyp = bmcrypto.verify(decoded.signPublicKey, dataToVerify, sig)
.then(function() {
return decoded;
});
return resolve(pubkeyp);
}
// v4 pubkey.
assert(objectPayload.length >= 32, "Bad pubkey v4 object payload length");
tag = decoded.tag = objectPayload.slice(0, 32);
addr = findAddrByTag(opts.needed, tag);
assert(addr, "You are not interested in this pubkey v4");
pubkeyPrivateKey = addr.getPubkeyPrivateKey();
dataToDecrypt = objectPayload.slice(32);
pubkeyp = bmcrypto
.decrypt(pubkeyPrivateKey, dataToDecrypt)
.then(function(decrypted) {
// 4 + 64 + 64 + (1+) + (1+) + (1+)
assert(
decrypted.length >= 135,
"Bad pubkey v4 object payload length");
objectAssign(decoded, extractPubkeyV3(decrypted));
siglen = util.popkey(decoded, "_siglen");
dataToVerify = Buffer.concat([
// Object header without nonce + tag.
buf.slice(8, decoded.headerLength + 32),
// Unencrypted pubkey data without signature.
decrypted.slice(0, decoded.length - siglen),
]);
sig = decoded.signature;
// Since data is encrypted, entire object payload is used.
decoded.length = objectPayload.length;
return bmcrypto.verify(decoded.signPublicKey, dataToVerify, sig);
}).then(function() {
return decoded;
});
resolve(pubkeyp);
});
},
/**
* Encode `pubkey` object message.
* @param {Object} opts - `pubkey` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* when fulfilled.
*/
encodeAsync: function(opts) {
return pubkey.encodePayloadAsync(opts).then(function(payload) {
return message.encode("object", payload);
});
},
/**
* Encode `pubkey` object message payload.
* @param {Object} opts - `pubkey` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* payload when fulfilled.
*/
encodePayloadAsync: function(opts) {
return new promise(function(resolve) {
opts = objectAssign({}, opts);
opts.type = object.PUBKEY;
// Originator of `pubkey` message.
var from = Address.decode(opts.from);
var nonceTrialsPerByte = util.getTrials(from);
var payloadLengthExtraBytes = util.getExtraBytes(from);
// Bitmessage address of recepient of `pubkey` message.
var to, version, stream;
if (opts.to) {
to = Address.decode(opts.to);
version = to.version;
stream = to.stream;
} else {
version = opts.version || 4;
stream = opts.stream || 1;
}
assert(version >= 2, "Address version is too low");
assert(version <= 4, "Address version is too high");
opts.version = version;
opts.stream = stream;
var obj, pubkeyp;
// v2 pubkey.
if (version === 2) {
opts.objectPayload = Buffer.concat([
from.behavior.buffer,
from.signPublicKey.slice(1),
from.encPublicKey.slice(1),
]);
obj = object.encodePayloadWithoutNonce(opts);
return resolve(prependNonce(obj, opts));
}
var pubkeyData = [
from.behavior.buffer,
from.signPublicKey.slice(1),
from.encPublicKey.slice(1),
var_int.encode(nonceTrialsPerByte),
var_int.encode(payloadLengthExtraBytes),
];
// v3 pubkey.
if (version === 3) {
opts.objectPayload = Buffer.concat(pubkeyData);
obj = object.encodePayloadWithoutNonce(opts);
pubkeyp = bmcrypto
.sign(from.signPrivateKey, obj)
.then(function(sig) {
// Append signature to the encoded object and we are done.
obj = Buffer.concat([obj, var_int.encode(sig.length), sig]);
return prependNonce(obj, opts);
});
return resolve(pubkeyp);
}
// v4 pubkey.
opts.objectPayload = from.getTag();
obj = object.encodePayloadWithoutNonce(opts);
var dataToSign = Buffer.concat([obj].concat(pubkeyData));
pubkeyp = bmcrypto
.sign(from.signPrivateKey, dataToSign)
.then(function(sig) {
var dataToEnc = pubkeyData.concat(var_int.encode(sig.length), sig);
dataToEnc = Buffer.concat(dataToEnc);
return bmcrypto.encrypt(from.getPubkeyPublicKey(), dataToEnc);
}).then(function(enc) {
// Concat object header with ecnrypted data and we are done.
obj = Buffer.concat([obj, enc]);
return prependNonce(obj, opts);
});
resolve(pubkeyp);
});
},
};
// Try to decrypt message with all provided identities.
function tryDecryptMsg(identities, buf) {
function inner(i) {
if (i > last) {
var err = new Error("Failed to decrypt msg with given identities");
return promise.reject(err);
}
return bmcrypto
.decrypt(identities[i].encPrivateKey, buf)
.then(function(decrypted) {
return {addr: identities[i], decrypted: decrypted};
}).catch(function() {
return inner(i + 1);
});
}
if (Address.isAddress(identities)) {
identities = [identities];
}
var last = identities.length - 1;
return inner(0);
}
// Encode message from the given options.
function encodeMessage(opts) {
var encoding = opts.encoding || DEFAULT_ENCODING;
var message = opts.message;
var subject = opts.subject;
if (encoding === msg.IGNORE && !message) {
// User may omit message for IGNORE encoding.
message = new Buffer(0);
} else if (!Buffer.isBuffer(message)) {
// User may specify message as a string.
message = new Buffer(message, "utf8");
}
if (encoding === msg.SIMPLE && subject) {
// User may specify subject for SIMPLE encoding.
if (!Buffer.isBuffer(subject)) {
subject = new Buffer(subject, "utf8");
}
message = Buffer.concat([
new Buffer("Subject:"),
subject,
new Buffer("\nBody:"),
message,
]);
}
return message;
}
// Decode message to the given encoding.
function decodeMessage(message, encoding) {
var decoded = {};
if (encoding === msg.TRIVIAL || encoding === msg.SIMPLE) {
message = message.toString("utf8");
}
if (encoding !== msg.SIMPLE) {
decoded.message = message;
return decoded;
}
// SIMPLE.
var subject, index;
if (message.slice(0, 8) === "Subject:") {
subject = message.slice(8);
index = subject.indexOf("\nBody:");
if (index !== -1) {
message = subject.slice(index + 6);
subject = subject.slice(0, index);
} else {
message = "";
}
decoded.subject = subject;
decoded.message = message;
} else {
decoded.subject = "";
decoded.message = message;
}
return decoded;
}
/**
* `msg` object.
* @see {@link https://bitmessage.org/wiki/Protocol_specification#msg}
* @namespace
* @static
*/
var msg = exports.msg = {
/**
* Any data with this number may be ignored. The sending node might
* simply be sharing its public key with you.
* @constant {number}
*/
IGNORE: 0,
/**
* UTF-8. No 'Subject' or 'Body' sections. Useful for simple strings
* of data, like URIs or magnet links.
* @constant {number}
*/
TRIVIAL: 1,
/**
* UTF-8. Uses 'Subject' and 'Body' sections. No MIME is used.
* @constant {number}
*/
SIMPLE: 2,
/**
* Decode `msg` object message.
* @param {Buffer} buf - Message
* @param {Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded `msg`
* object structure when fulfilled.
*/
decodeAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = message.decode(buf);
assert(decoded.command === "object", "Bad command");
resolve(msg.decodePayloadAsync(decoded.payload, opts));
});
},
/**
* Decode `msg` object message payload.
* @param {Buffer} buf - Message payload
* @param {Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded `msg`
* object structure when fulfilled.
*/
decodePayloadAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = object.decodePayload(buf, opts);
assert(decoded.type === object.MSG, "Bad object type");
assert(decoded.version === 1, "Bad msg version");
var objectPayload = util.popkey(decoded, "objectPayload");
var msgp = tryDecryptMsg(opts.identities, objectPayload)
.then(function(decInfo) {
var decrypted = decInfo.decrypted;
// Version, stream.
var decodedVersion = var_int.decode(decrypted);
var senderVersion = decoded.senderVersion = decodedVersion.value;
assert(senderVersion >= 2, "Sender version is too low");
assert(senderVersion <= 4, "Sender version is too high");
var decodedStream = var_int.decode(decodedVersion.rest);
decoded.senderStream = decodedStream.value;
// Behavior, keys.
assert(
decodedStream.rest.length >= 132,
"Bad msg object payload length");
objectAssign(decoded, extractPubkey(decodedStream.rest));
decoded.length += decodedVersion.length + decodedStream.length;
var rest = decrypted.slice(decoded.length);
// Pow extra.
if (decoded.senderVersion >= 3) {
var decodedTrials = var_int.decode(rest);
decoded.nonceTrialsPerByte = decodedTrials.value;
decoded.length += decodedTrials.length;
var decodedExtraBytes = var_int.decode(decodedTrials.rest);
decoded.payloadLengthExtraBytes = decodedExtraBytes.value;
decoded.length += decodedExtraBytes.length;
rest = decodedExtraBytes.rest;
}
// Ripe, encoding.
assert(rest.length >= 20, "Bad msg object payload length");
decoded.ripe = rest.slice(0, 20);
// TODO(Kagami): Also check against the calculated ripe (see
// GH-6)?
assert(
bufferEqual(decoded.ripe, decInfo.addr.ripe),
"msg was decrypted but the destination ripe doesn't match");
decoded.length += 20;
var decodedEncoding = var_int.decode(rest.slice(20));
var encoding = decoded.encoding = decodedEncoding.value;
decoded.length += decodedEncoding.length;
// Message.
var decodedMsgLength = var_int.decode(decodedEncoding.rest);
var msglen = decodedMsgLength.value;
rest = decodedMsgLength.rest;
assert(rest.length >= msglen, "Bad msg object payload length");
decoded.length += decodedMsgLength.length + msglen;
var message = rest.slice(0, msglen);
objectAssign(decoded, decodeMessage(message, encoding));
// Acknowledgement data.
// TODO(Kagami): Validate ack, check a POW.
var decodedAckLength = var_int.decode(rest.slice(msglen));
var acklen = decodedAckLength.value;
rest = decodedAckLength.rest;
assert(rest.length >= acklen, "Bad msg object payload length");
decoded.length += decodedAckLength.length + acklen;
decoded.ack = rest.slice(0, acklen);
// Signature.
var decodedSigLength = var_int.decode(rest.slice(acklen));
var siglen = decodedSigLength.value;
rest = decodedSigLength.rest;
assert(rest.length >= siglen, "Bad msg object payload length");
var sig = decoded.signature = rest.slice(0, siglen);
// Verify signature.
var dataToVerify = Buffer.concat([
// Object header without nonce.
buf.slice(8, decoded.headerLength),
// Unencrypted pubkey data without signature.
decrypted.slice(0, decoded.length),
]);
// Since data is encrypted, entire object payload is used.
decoded.length = objectPayload.length;
return bmcrypto.verify(decoded.signPublicKey, dataToVerify, sig);
}).then(function() {
return decoded;
});
resolve(msgp);
});
},
/**
* Encode `msg` object message.
* @param {Object} opts - `msg` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* when fulfilled.
*/
encodeAsync: function(opts) {
return msg.encodePayloadAsync(opts).then(function(payload) {
return message.encode("object", payload);
});
},
/**
* Encode `msg` object message payload.
* @param {Object} opts - `msg` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* payload when fulfilled.
*/
encodePayloadAsync: function(opts) {
return new promise(function(resolve) {
// Deal with options.
opts = objectAssign({}, opts);
opts.type = object.MSG;
opts.version = 1; // The only known msg version
var from = Address.decode(opts.from);
assert(from.version >= 2, "Address version is too low");
assert(from.version <= 4, "Address version is too high");
var to = Address.decode(opts.to);
opts.stream = to.stream;
var nonceTrialsPerByte, payloadLengthExtraBytes;
if (from.version >= 3) {
if (opts.friend) {
nonceTrialsPerByte = util.DEFAULT_TRIALS_PER_BYTE;
payloadLengthExtraBytes = util.DEFAULT_EXTRA_BYTES;
} else {
nonceTrialsPerByte = util.getTrials(from);
payloadLengthExtraBytes = util.getExtraBytes(from);
}
}
var encoding = opts.encoding || DEFAULT_ENCODING;
var message = encodeMessage(opts);
// Assemble the unencrypted message data.
var msgData = [
var_int.encode(from.version),
var_int.encode(from.stream),
from.behavior.buffer,
from.signPublicKey.slice(1),
from.encPublicKey.slice(1),
];
if (from.version >= 3) {
msgData.push(
var_int.encode(nonceTrialsPerByte),
var_int.encode(payloadLengthExtraBytes)
);
}
msgData.push(
to.ripe,
var_int.encode(encoding),
var_int.encode(message.length),
message
);
// TODO(Kagami): Calculate ACK.
msgData.push(var_int.encode(0));
// Sign and encrypt.
opts.objectPayload = new Buffer(0);
var obj = object.encodePayloadWithoutNonce(opts);
var dataToSign = Buffer.concat([obj].concat(msgData));
var msgp = bmcrypto
.sign(from.signPrivateKey, dataToSign)
.then(function(sig) {
var dataToEnc = msgData.concat(var_int.encode(sig.length), sig);
dataToEnc = Buffer.concat(dataToEnc);
return bmcrypto.encrypt(to.encPublicKey, dataToEnc);
}).then(function(enc) {
// Concat object header with ecnrypted data and we are done.
obj = Buffer.concat([obj, enc]);
// TODO(Kagami): Merge receiver's trials/extra bytes options
// so we can calculate right POW (now we need to pass them to
// opts manually).
return prependNonce(obj, opts);
});
resolve(msgp);
});
},
};
var DEFAULT_ENCODING = msg.TRIVIAL;
// Try to decrypt broadcast v4 with all provided subscription objects.
function tryDecryptBroadcastV4(subscriptions, buf) {
function inner(i) {
if (i > last) {
var err = new Error("Failed to decrypt broadcast with given identities");
return promise.reject(err);
}
return bmcrypto
.decrypt(subscriptions[i].getBroadcastPrivateKey(), buf)
.then(function(decrypted) {
return {addr: subscriptions[i], decrypted: decrypted};
}).catch(function() {
return inner(i + 1);
});
}
if (Address.isAddress(subscriptions)) {
subscriptions = [subscriptions];
} else if (!Array.isArray(subscriptions)) {
subscriptions = Object.keys(subscriptions).map(function(k) {
return subscriptions[k];
});
}
// Only addresses with version < 4 may be used to encode broadcast v4.
subscriptions = subscriptions.filter(function(a) {
return a.version < 4;
});
var last = subscriptions.length - 1;
return inner(0);
}
/**
* `broadcast` object.
* @see {@link https://bitmessage.org/wiki/Protocol_specification#broadcast}
* @namespace
* @static
*/
var broadcast = exports.broadcast = {
/**
* Decode `broadcast` object message.
* @param {Buffer} buf - Message
* @param {Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded
* `broadcast` object structure when fulfilled.
*/
decodeAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = message.decode(buf);
assert(decoded.command === "object", "Bad command");
resolve(broadcast.decodePayloadAsync(decoded.payload, opts));
});
},
/**
* Decode `broadcast` object message payload.
* @param {Buffer} buf - Message payload
* @param {Object} opts - Decoding options
* @return {Promise.<Object>} A promise that contains decoded `pubkey`
* object structure when fulfilled.
*/
decodePayloadAsync: function(buf, opts) {
return new promise(function(resolve) {
var decoded = object.decodePayload(buf, opts);
assert(decoded.type === object.BROADCAST, "Bad object type");
var version = decoded.version;
assert(version === 4 || version === 5, "Bad broadcast version");
var objectPayload = util.popkey(decoded, "objectPayload");
var tag, addr, broadPrivateKey, dataToDecrypt, broadp;
if (version === 4) {
broadp = tryDecryptBroadcastV4(opts.subscriptions, objectPayload);
} else {
assert(
objectPayload.length >= 32,
"Bad broadcast v5 object payload length");
tag = decoded.tag = objectPayload.slice(0, 32);
addr = findAddrByTag(opts.subscriptions, tag);
assert(addr, "You are not interested in this broadcast v5");
broadPrivateKey = addr.getBroadcastPrivateKey();
dataToDecrypt = objectPayload.slice(32);
broadp = bmcrypto
.decrypt(broadPrivateKey, dataToDecrypt)
.then(function(decrypted) {
return {addr: addr, decrypted: decrypted};
});
}
broadp = broadp.then(function(decInfo) {
var decrypted = decInfo.decrypted;
// Version, stream.
var decodedVersion = var_int.decode(decrypted);
var senderVersion = decoded.senderVersion = decodedVersion.value;
if (version === 4) {
assert(senderVersion >= 2, "Sender version is too low");
assert(senderVersion <= 3, "Sender version is too high");
} else {
assert(senderVersion === 4, "Bad sender version");
}
var decodedStream = var_int.decode(decodedVersion.rest);
var senderStream = decoded.senderStream = decodedStream.value;
assert(
senderStream === decoded.stream,
"Cleartext broadcast object stream doesn't match encrypted");
// Behavior, keys.
assert(
decodedStream.rest.length >= 132,
"Bad broadcast object payload length");
objectAssign(decoded, extractPubkey(decodedStream.rest));
decoded.length += decodedVersion.length + decodedStream.length;
var rest = decrypted.slice(decoded.length);
var sender = new Address({
version: senderVersion,
stream: senderStream,
signPublicKey: decoded.signPublicKey,
encPublicKey: decoded.encPublicKey,
});
if (version === 4) {
assert(
bufferEqual(sender.ripe, decInfo.addr.ripe),
"The keys used to encrypt the broadcast doesn't match the keys "+
"embedded into the object");
} else {
assert(
bufferEqual(sender.getTag(), tag),
"The tag used to encrypt the broadcast doesn't match the keys "+
"and version/stream embedded into the object");
}
// Pow extra.
if (senderVersion >= 3) {
var decodedTrials = var_int.decode(rest);
decoded.nonceTrialsPerByte = decodedTrials.value;
decoded.length += decodedTrials.length;
var decodedExtraBytes = var_int.decode(decodedTrials.rest);
decoded.payloadLengthExtraBytes = decodedExtraBytes.value;
decoded.length += decodedExtraBytes.length;
rest = decodedExtraBytes.rest;
}
// Encoding, message
var decodedEncoding = var_int.decode(rest);
var encoding = decoded.encoding = decodedEncoding.value;
decoded.length += decodedEncoding.length;
var decodedMsgLength = var_int.decode(decodedEncoding.rest);
var msglen = decodedMsgLength.value;
rest = decodedMsgLength.rest;
assert(rest.length >= msglen, "Bad broadcast object payload length");
decoded.length += decodedMsgLength.length + msglen;
var message = rest.slice(0, msglen);
objectAssign(decoded, decodeMessage(message, encoding));
// Signature.
var decodedSigLength = var_int.decode(rest.slice(msglen));
var siglen = decodedSigLength.value;
rest = decodedSigLength.rest;
assert(rest.length >= siglen, "Bad broadcast object payload length");
var sig = decoded.signature = rest.slice(0, siglen);
// Verify signature.
var headerLength = decoded.headerLength;
if (version !== 4) {
// Compensate for tag.
headerLength += 32;
}
var dataToVerify = Buffer.concat([
// Object header without nonce.
buf.slice(8, headerLength),
// Unencrypted pubkey data without signature.
decrypted.slice(0, decoded.length),
]);
// Since data is encrypted, entire object payload is used.
decoded.length = objectPayload.length;
return bmcrypto.verify(decoded.signPublicKey, dataToVerify, sig);
}).then(function() {
return decoded;
});
resolve(broadp);
});
},
/**
* Encode `broadcast` object message.
* @param {Object} opts - `broadcast` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* when fulfilled.
*/
encodeAsync: function(opts) {
return broadcast.encodePayloadAsync(opts).then(function(payload) {
return message.encode("object", payload);
});
},
/**
* Encode `broadcast` object message payload.
* @param {Object} opts - `broadcast` object options
* @return {Promise.<Buffer>} A promise that contains encoded message
* payload when fulfilled.
*/
encodePayloadAsync: function(opts) {
return new promise(function(resolve) {
// Deal with options.
opts = objectAssign({}, opts);
opts.type = object.BROADCAST;
var from = Address.decode(opts.from);
assert(from.version >= 2, "Address version is too low");
assert(from.version <= 4, "Address version is too high");
opts.version = from.version >= 4 ? 5 : 4;
opts.stream = from.stream;
var encoding = opts.encoding || DEFAULT_ENCODING;
var message = encodeMessage(opts);
// Assemble the unencrypted message data.
var broadData = [
var_int.encode(from.version),
var_int.encode(from.stream),
from.behavior.buffer,
from.signPublicKey.slice(1),
from.encPublicKey.slice(1),
];
if (from.version >= 3) {
broadData.push(
var_int.encode(util.getTrials(from)),
var_int.encode(util.getExtraBytes(from))
);
}
broadData.push(
var_int.encode(encoding),
var_int.encode(message.length),
message
);
// Sign and encrypt.
opts.objectPayload = from.version >= 4 ? from.getTag() : new Buffer(0);
var obj = object.encodePayloadWithoutNonce(opts);
var dataToSign = Buffer.concat([obj].concat(broadData));
var broadp = bmcrypto
.sign(from.signPrivateKey, dataToSign)
.then(function(sig) {
var dataToEnc = broadData.concat(var_int.encode(sig.length), sig);
dataToEnc = Buffer.concat(dataToEnc);
return bmcrypto.encrypt(from.getBroadcastPublicKey(), dataToEnc);
}).then(function(enc) {
obj = Buffer.concat([obj, enc]);
return prependNonce(obj, opts);
});
resolve(broadp);
});
},
};