mirror of
https://github.com/amark/gun.git
synced 2025-03-30 15:08:33 +00:00
334 lines
15 KiB
JavaScript
334 lines
15 KiB
JavaScript
;(function(){
|
|
/*
|
|
Security, Encryption, and Authorization: SEA.js
|
|
*/
|
|
|
|
// NECESSARY PRE-REQUISITE: http://gun.js.org/explainers/data/security.html
|
|
|
|
/* THIS IS AN EARLY ALPHA!!! */
|
|
|
|
if(typeof require !== "undefined"){ var Gun = require('./gun') }
|
|
if(typeof window !== "undefined"){ var Gun = window.Gun }
|
|
|
|
// let's extend the gun chain with a `user` function.
|
|
// only one user can be logged in at a time, per gun instance.
|
|
Gun.chain.user = function(){
|
|
var root = this.back(-1); // always reference the root gun instance.
|
|
var user = root._.user || (root._.user = root.chain()); // create a user context.
|
|
user.create = User.create; // attach a factory method to it.
|
|
user.auth = User.auth; // and a login method.
|
|
return user; // return the user!
|
|
}
|
|
|
|
// EXAMPLE! Use it this way:
|
|
;(function(){return;
|
|
localStorage.clear();
|
|
|
|
var gun = Gun();
|
|
var user = gun.user();
|
|
|
|
gun.on('auth', function(at){
|
|
// do something once logged in.
|
|
});
|
|
gun.on('secure', function(at){
|
|
// enforce some rules about shared app level data
|
|
var no;
|
|
if(no){ return }
|
|
this.to.next(at);
|
|
});
|
|
|
|
user.create("test", "password"); // create a user from a username alias and a password phrase.
|
|
user.auth("test", "password"); // authenticate and log in the user!
|
|
|
|
}());
|
|
|
|
// How does it work?
|
|
function User(){};
|
|
// Well first we have to actually create a user. That is what this function does.
|
|
User.create = function(alias, pass, cb){
|
|
var root = this.back(-1);
|
|
cb = cb || function(){};
|
|
// Because more than 1 user might have the same username, we treat the alias as a list of those users.
|
|
root.get('alias/'+alias).get(function(at, ev){
|
|
ev.off();
|
|
if(at.put){
|
|
// If we can enforce that a user name is already taken, it might be nice to try, but this is not guaranteed.
|
|
return cb({err: Gun.log("User already created!")});
|
|
}
|
|
var user = {alias: alias, salt: Gun.text.random(64)};
|
|
// pseudo-randomly create a salt, then use CryptoJS's PBKDF2 function to extend the password with it.
|
|
SEA.proof(pass, user.salt, function(proof){
|
|
// this will take some short amount of time to produce a proof, which slows brute force attacks.
|
|
var pair = SEA.pair();
|
|
// now we have generated a brand new ECDSA key pair for the user account.
|
|
user.pub = pair.pub;
|
|
// the user's public key doesn't need to be signed. But everything else needs to be signed with it!
|
|
user.alias = SEA.write(alias, pair.priv);
|
|
user.salt = SEA.write(user.salt, pair.priv);
|
|
// to keep the private key safe, we AES encrypt it with the proof of work!
|
|
user.auth = SEA.write(SEA.en(pair.priv, proof), pair.priv);
|
|
var tmp = 'pub/'+pair.pub;
|
|
//console.log("create", user, pair.pub);
|
|
// awesome, now we can actually save the user with their public key as their ID.
|
|
root.get(tmp).put(user);
|
|
// next up, we want to associate the alias with the public key. So we add it to the alias list.
|
|
var ref = root.get('alias/'+alias).put(Gun.obj.put({}, tmp, Gun.val.rel.ify(tmp)));
|
|
// callback that the user has been created. (Note: ok = 0 because we didn't wait for disk to ack)
|
|
cb({ok: 0, pub: pair.pub});
|
|
});
|
|
});
|
|
}
|
|
// now that we have created a user, we want to authenticate them!
|
|
User.auth = function(alias, pass, cb){
|
|
var root = this.back(-1);
|
|
cb = cb || function(){};
|
|
// load all public keys associated with the username alias we want to log in with.
|
|
root.get('alias/'+alias).get(function(at, ev){
|
|
ev.off();
|
|
if(!at.put){
|
|
// if no user, don't do anything.
|
|
return cb({err: Gun.log("No user!")});
|
|
}
|
|
// then attempt to log into each one until we find ours!
|
|
// (if two users have the same username AND the same password... that would be bad)
|
|
Gun.obj.map(at.put, function(val, key){
|
|
// grab the account associated with this public key.
|
|
root.get(key).get(function(at, ev){
|
|
key = key.slice(4);
|
|
ev.off();
|
|
if(!at.put){ return cb({err: "Public key does not exist!"}) }
|
|
// attempt to PBKDF2 extend the password with the salt. (Verifying the signature gives us the plain text salt.)
|
|
SEA.proof(pass, SEA.read(at.put.salt, key), function(proof){
|
|
// the proof of work is evidence that we've spent some time/effort trying to log in, this slows brute force.
|
|
var priv = SEA.de(SEA.read(at.put.auth, key), proof);
|
|
// now we have AES decrypted the private key, from when we encrypted it with the proof at registration.
|
|
if(priv){ // if we were successful, then that means...
|
|
// we're logged in!
|
|
var user = root._.user;
|
|
// add our credentials in-memory only to our root gun instance
|
|
user._ = at.gun._;
|
|
// so that way we can use the credentials to encrypt/decrypt data
|
|
user._.is = user.is = {};
|
|
// that is input/output through gun (see below)
|
|
user._.sea = priv;
|
|
user._.pub = key;
|
|
//console.log("authorized", user._);
|
|
// callbacks success with the user data credentials.
|
|
cb(user._);
|
|
// emit an auth event, useful for page redirects and stuff.
|
|
root.on('auth', user._);
|
|
return;
|
|
}
|
|
// Or else we failed to log in...
|
|
console.log("Failed to sign in!");
|
|
cb({err: "Attempt failed"});
|
|
});
|
|
});
|
|
});
|
|
});
|
|
}
|
|
// After we have a GUN extension to make user registration/login easy, we then need to handle everything else.
|
|
|
|
// We do this with a GUN adapter, we first listen to when a gun instance is created (and when its options change)
|
|
Gun.on('opt', function(at){
|
|
if(!at.sea){ // only add SEA once per instance, on the "at" context.
|
|
at.sea = {own: {}};
|
|
at.gun.on('in', security, at); // now listen to all input data, acting as a firewall.
|
|
at.gun.on('out', signature, at); // and output listeners, to encrypt outgoing data.
|
|
at.gun.on('node', every, at);
|
|
}
|
|
this.to.next(at); // make sure to call the "next" middleware adapter.
|
|
});
|
|
|
|
// Alright, this next adapter gets run at the per node level in the graph database.
|
|
// This will let us verify that every property on a node has a value signed by a public key we trust.
|
|
// If the signature does not match, the data is just `undefined` so it doesn't get passed on.
|
|
// If it does match, then we transform the in-memory "view" of the data into its plain value (without the signature).
|
|
// Now NOTE! Some data is "system" data, not user data. Example: List of public keys, aliases, etc.
|
|
// This data is self-enforced (the value can only match its ID), but that is handled in the `security` function.
|
|
// From the self-enforced data, we can see all the edges in the graph that belong to a public key.
|
|
// Example: pub/ASDF is the ID of a node with ASDF as its public key, signed alias and salt, and
|
|
// its encrypted private key, but it might also have other signed values on it like `profile = <ID>` edge.
|
|
// Using that directed edge's ID, we can then track (in memory) which IDs belong to which keys.
|
|
// Here is a problem: Multiple public keys can "claim" any node's ID, so this is dangerous!
|
|
// This means we should ONLY trust our "friends" (our key ring) public keys, not any ones.
|
|
// I have not yet added that to SEA yet in this alpha release. That is coming soon, but beware in the meanwhile!
|
|
function every(at){
|
|
var own = (at.gun.back(-1)._).sea.own, soul = at.get, pub = own[soul] || soul.slice(4), vertex = (at.gun._).put;
|
|
Gun.node.is(at.put, function(val, key, node){ // for each property on the node.
|
|
vertex[key] = node[key] = val = SEA.read(val, pub); // verify signature and get plain value.
|
|
if(val && val['#'] && (key = Gun.val.rel.is(val))){ // if it is a relation / edge
|
|
if('alias/' === soul.slice(0,6)){ return } // if it is itself
|
|
own[key] = pub; // associate the public key with a node
|
|
}
|
|
});
|
|
};
|
|
|
|
// signature handles data output, it is a proxy to the security function.
|
|
function signature(at){
|
|
at.user = at.gun.back(-1)._.user;
|
|
security.call(this, at);
|
|
}
|
|
|
|
// okay! The security function handles all the heavy lifting.
|
|
// It needs to deal read and write of input and output of system data, account/public key data, and regular data.
|
|
// This is broken down into some pretty clear edge cases, let's go over them:
|
|
function security(at){
|
|
var cat = this.as, sea = cat.sea, to = this.to;
|
|
if(at.get){
|
|
// if there is a request to read data from us, then...
|
|
var soul = at.get['#'];
|
|
if(soul){ // for now, only allow direct IDs to be read.
|
|
if('alias' === soul){ // Allow reading the list of usernames/aliases in the system?
|
|
return to.next(at); // yes.
|
|
} else
|
|
if('alias/' === soul.slice(0,6)){ // Allow reading the list of public keys associated with an alias?
|
|
return to.next(at); // yes.
|
|
} else { // Allow reading everything?
|
|
return to.next(at); // yes // TODO: No! Make this a callback/event that people can filter on.
|
|
}
|
|
}
|
|
}
|
|
if(at.put){
|
|
// if there is a request to write data to us, then...
|
|
var no, tmp, u;
|
|
Gun.obj.map(at.put, function(node, soul){ // for each over every node in the graph
|
|
if(no){ return no = true }
|
|
if(Gun.obj.empty(node, '_')){ return } // ignore empty updates, don't reject them.
|
|
if('alias' === soul){ // special case for shared system data, the list of aliases.
|
|
Gun.obj.map(node, function(val, key){ // for each over the node to look at each property/value.
|
|
if('_' === key){ return } // ignore meta data
|
|
if(!val){ return no = true } // data MUST exist
|
|
if('alias/'+key !== Gun.val.rel.is(val)){ // in fact, it must be EXACTLY equal to itself
|
|
return no = true; // if it isn't, reject.
|
|
}
|
|
});
|
|
} else
|
|
if('alias/' === soul.slice(0,6)){ // special case for shared system data, the list of public keys for an alias.
|
|
Gun.obj.map(node, function(val, key){ // for each over the node to look at each property/value.
|
|
if('_' === key){ return } // ignore meta data
|
|
if(!val){ return no = true } // data MUST exist
|
|
if(key === Gun.val.rel.is(val)){ return } // and the ID must be EXACTLY equal to its property
|
|
return no = true; // that way nobody can tamper with the list of public keys.
|
|
});
|
|
} else
|
|
if('pub/' === soul.slice(0,4)){ // special case, account data for a public key.
|
|
tmp = soul.slice(4); // ignore the 'pub/' prefix on the public key.
|
|
Gun.obj.map(node, function(val, key){ // for each over the account data, looking at each property/value.
|
|
if('_' === key){ return } // ignore meta data.
|
|
if('pub' === key){
|
|
if(val === tmp){ return } // the account MUST have a `pub` property that equals the ID of the public key.
|
|
return no = true; // if not, reject the update.
|
|
}
|
|
if(at.user){ // if we are logged in
|
|
if(tmp === at.user._.pub){ // as this user
|
|
val = node[key] = SEA.write(val, at.user._.sea); // then sign our updates as we output them.
|
|
} // (if we are lying about our signature, other peer's will reject our update)
|
|
}
|
|
if(u === (val = SEA.read(val, tmp))){ // make sure the signature matches the account it claims to be on.
|
|
return no = true; // reject any updates that are signed with a mismatched account.
|
|
}
|
|
});
|
|
} else
|
|
if(at.user && (tmp = at.user._.sea)){ // not special case, if we are logged in, then
|
|
Gun.obj.map(node, function(val, key){ // any data we output needs to
|
|
if('_' === key){ return }
|
|
node[key] = SEA.write(val, tmp); // be signed by our logged in account.
|
|
});
|
|
} else // TODO: BUG! These two if-statements are not exclusive to each other!!!
|
|
if(tmp = sea.own[soul]){ // not special case, if we receive an update on an ID associated with a public key, then
|
|
Gun.obj.map(node, function(val, key){ // for each over the property/values
|
|
if('_' === key){ return }
|
|
if(u === (val = SEA.read(val, tmp))){ // and verify they were signed by the associated public key!
|
|
return no = true; // reject the update if it fails to match.
|
|
}
|
|
});
|
|
} else { // reject any/all other updates by default.
|
|
return no = true;
|
|
}
|
|
});
|
|
if(no){ // if we got a rejection then...
|
|
if(!at || !Gun.tag.secure){ return }
|
|
cat.on('secure', function(at){ // (below) emit a special event for the developer to handle security.
|
|
this.off();
|
|
if(!at){ return }
|
|
to.next(at); // and if they went ahead and explicitly called "next" (to us) with data, then approve.
|
|
});
|
|
cat.on('secure', at);
|
|
return; // else wise, reject.
|
|
}
|
|
//console.log("SEA put", at.put);
|
|
// if we did not get a rejection, then pass forward to the "next" adapter middleware.
|
|
return to.next(at);
|
|
}
|
|
to.next(at); // pass forward any data we do not know how to handle or process (this allows custom security protocols).
|
|
}
|
|
|
|
function SEA(){};
|
|
// create a wrapper library around CryptoJS and JSRSAsign.
|
|
// of course, these libraries are required. A bundle is included in lib/cryptography.js
|
|
if(typeof CryptoJS === "undefined"){ console.log("Error: CryptoJS required!") }
|
|
if(typeof KJUR === "undefined"){ console.log("Error: JSRSAsign required!") }
|
|
// now wrap the various AES, ECDSA, PBKDF2 functions we called above.
|
|
SEA.proof = function(pass,salt,cb){
|
|
cb(CryptoJS.PBKDF2(pass, salt, {keySize: 512/32, iterations: 100}).toString(CryptoJS.enc.Base64));
|
|
};
|
|
SEA.pair = function(){
|
|
var master = new KJUR.crypto.ECDSA({"curve": 'secp256r1'});
|
|
var pair = master.generateKeyPairHex();
|
|
return {pub: pair.ecpubhex, priv: pair.ecprvhex};
|
|
};
|
|
SEA.sign = function(m, p){
|
|
var sig = new KJUR.crypto.Signature({'alg': 'SHA256withECDSA'});
|
|
sig.initSign({'ecprvhex': p, 'eccurvename': 'secp256r1'});
|
|
sig.updateString(JSON.stringify(m));
|
|
return sig.sign();
|
|
}
|
|
SEA.verify = function(m, p, s){
|
|
var sig = new KJUR.crypto.Signature({'alg': 'SHA256withECDSA', 'prov': "cryptojs/jsrsa"}), yes;
|
|
try{
|
|
sig.initVerifyByPublicKey({'ecpubhex': p, 'eccurvename': 'secp256r1'});
|
|
sig.updateString(JSON.stringify(m));
|
|
yes = sig.verify(s);
|
|
}catch(e){Gun.log(e)}
|
|
return yes;
|
|
}
|
|
SEA.write = function(m, p){
|
|
return 'SEA'+JSON.stringify([m,SEA.sign(m,p)]);
|
|
return JSON.stringify([m,SEA.sign(m,p)]);
|
|
}
|
|
SEA.read = function(m, p){
|
|
if(!m){ return }
|
|
if(!m.slice || 'SEA[' !== m.slice(0,4)){ return m }
|
|
m = m.slice(3);
|
|
try{m = JSON.parse(m);
|
|
}catch(e){ return }
|
|
m = m || '';
|
|
if(SEA.verify(m[0], p, m[1])){
|
|
return m[0];
|
|
}
|
|
}
|
|
SEA.en = function(m, p){
|
|
return CryptoJS.AES.encrypt(JSON.stringify(m), p, {format:SEA.froto}).toString();
|
|
};
|
|
SEA.de = function(m, p){
|
|
var r;
|
|
try{r = CryptoJS.AES.decrypt(m, p, {format:SEA.froto}).toString(CryptoJS.enc.Utf8);
|
|
r = JSON.parse(r);
|
|
}catch(e){};
|
|
return r;
|
|
};
|
|
SEA.froto = {stringify:function(a){var b={ct:a.ciphertext.toString(CryptoJS.enc.Base64)};a.iv&&(b.iv=a.iv.toString());a.salt&&(b.s=a.salt.toString());return JSON.stringify(b)},parse:function(a){a=JSON.parse(a);var b=CryptoJS.lib.CipherParams.create({ciphertext:CryptoJS.enc.Base64.parse(a.ct)});a.iv&&(b.iv=CryptoJS.enc.Hex.parse(a.iv));a.s&&(b.salt=CryptoJS.enc.Hex.parse(a.s));return b}};
|
|
Gun.SEA = SEA;
|
|
|
|
// all done!
|
|
// Obviously it is missing MANY necessary features. This is only an alpha release.
|
|
// Please experiment with it, audit what I've done so far, and complain about what needs to be added.
|
|
// SEA should be a full suite that is easy and seamless to use.
|
|
// Again, scroll naer the top, where I provide an EXAMPLE of how to create a user and sign in.
|
|
// Once logged in, the rest of the code you just read handled automatically signing/validating data.
|
|
// But all other behavior needs to be equally easy, like opinionated ways of
|
|
// Adding friends (trusted public keys), sending private messages, etc.
|
|
// Cheers! Tell me what you think.
|
|
|
|
}()); |