WIP

calvinmetcalf · Apr 5, 2016 · 3bd6471 · 3bd6471
1 parent 4d525a8
commit 3bd6471
Show file tree

Hide file tree

Showing 5 changed files with 145 additions and 81 deletions.
diff --git a/bundle.js b/bundle.js
@@ -24548,10 +24548,22 @@ function genKey(password, salt) {
     });
   });
 }
-function cryptoInit(password, modP) {
+function cryptoInit(password, options) {
   var db = this;
   var key, pub;
   var turnedOff = false;
+  var ignore = ['_id', '_rev']
+  var modP
+
+  if (typeof options === 'string' || Buffer.isBuffer(options)) {
+    modP = options
+  }
+  if (options && options.ignore) {
+    ignore = ignore.concat(options.ignore)
+  }
+  if (options && options.modP) {
+    modP = options.modP
+  }
   return db.get(configId).catch(function (err) {
     if (err.status === 404) {
       var doc = {
@@ -24596,35 +24608,28 @@ function cryptoInit(password, modP) {
     if (turnedOff) {
       return doc;
     }
-    var id, rev, attachments;
-    if ('_id' in doc) {
-      id = doc._id;
-      delete doc._id;
-    } else {
-      id = uuid.v4();
-    }
-    if ('_rev' in doc) {
-      rev = doc._rev;
-      delete doc._rev;
-    }
-    if ('_attachments' in doc) {
-      attachments = doc._attachments;
-      delete doc._attachments;
-    }
     var nonce = crypto.randomBytes(12);
-    var data = JSON.stringify(doc);
     var outDoc = {
-      _id: id,
       nonce: nonce.toString('hex')
-    };
-    if (rev) {
-      outDoc._rev = rev;
     }
-    if (attachments) {
-      outDoc._attachments = attachments;
+    // for loop performs better than .forEach etc
+    for (var i = 0, len = ignore.length; i < len; i++) {
+      outDoc[ignore[i]] = doc[ignore[i]]
+      delete doc[ignore[i]]
+    }
+    if (!outDoc._id) {
+      outDoc._id = uuid.v4()
+    }
+
+    // Encrypting attachments is complicated
+    // https://github.com/calvinmetcalf/crypto-pouch/pull/18#issuecomment-186402231
+    if (doc._attachments) {
+      throw new Error('Attachments cannot be encrypted. Use {ignore: "_attachments"} option')
     }
+
+    var data = JSON.stringify(doc);
     var cipher = chacha.createCipher(key, nonce);
-    cipher.setAAD(new Buffer(id));
+    cipher.setAAD(new Buffer(outDoc._id));
     outDoc.data = cipher.update(data).toString('hex');
     cipher.final();
     outDoc.tag = cipher.getAuthTag().toString('hex');
@@ -24642,9 +24647,9 @@ function cryptoInit(password, modP) {
     // parse it AFTER calling final
     // you don't want to parse it if it has been manipulated
     out = JSON.parse(out);
-    out._id = doc._id;
-    out._rev = doc._rev;
-    out._attachments = doc._attachments;
+    for (var i = 0, len = ignore.length; i < len; i++) {
+      out[ignore[i]] = doc[ignore[i]]
+    }
     return out;
   }
 }

diff --git a/index.js b/index.js
@@ -16,10 +16,22 @@ function genKey(password, salt) {
     });
   });
 }
-function cryptoInit(password, modP) {
+function cryptoInit(password, options) {
   var db = this;
   var key, pub;
   var turnedOff = false;
+  var ignore = ['_id', '_rev']
+  var modP
+
+  if (typeof options === 'string' || Buffer.isBuffer(options)) {
+    modP = options
+  }
+  if (options && options.ignore) {
+    ignore = ignore.concat(options.ignore)
+  }
+  if (options && options.modP) {
+    modP = options.modP
+  }
   return db.get(configId).catch(function (err) {
     if (err.status === 404) {
       var doc = {
@@ -64,35 +76,28 @@ function cryptoInit(password, modP) {
     if (turnedOff) {
       return doc;
     }
-    var id, rev, attachments;
-    if ('_id' in doc) {
-      id = doc._id;
-      delete doc._id;
-    } else {
-      id = uuid.v4();
-    }
-    if ('_rev' in doc) {
-      rev = doc._rev;
-      delete doc._rev;
-    }
-    if ('_attachments' in doc) {
-      attachments = doc._attachments;
-      delete doc._attachments;
-    }
     var nonce = crypto.randomBytes(12);
-    var data = JSON.stringify(doc);
     var outDoc = {
-      _id: id,
       nonce: nonce.toString('hex')
-    };
-    if (rev) {
-      outDoc._rev = rev;
     }
-    if (attachments) {
-      outDoc._attachments = attachments;
+    // for loop performs better than .forEach etc
+    for (var i = 0, len = ignore.length; i < len; i++) {
+      outDoc[ignore[i]] = doc[ignore[i]]
+      delete doc[ignore[i]]
+    }
+    if (!outDoc._id) {
+      outDoc._id = uuid.v4()
+    }
+
+    // Encrypting attachments is complicated
+    // https://github.com/calvinmetcalf/crypto-pouch/pull/18#issuecomment-186402231
+    if (doc._attachments) {
+      throw new Error('Attachments cannot be encrypted. Use {ignore: "_attachments"} option')
     }
+
+    var data = JSON.stringify(doc);
     var cipher = chacha.createCipher(key, nonce);
-    cipher.setAAD(new Buffer(id));
+    cipher.setAAD(new Buffer(outDoc._id));
     outDoc.data = cipher.update(data).toString('hex');
     cipher.final();
     outDoc.tag = cipher.getAuthTag().toString('hex');
@@ -110,9 +115,9 @@ function cryptoInit(password, modP) {
     // parse it AFTER calling final
     // you don't want to parse it if it has been manipulated
     out = JSON.parse(out);
-    out._id = doc._id;
-    out._rev = doc._rev;
-    out._attachments = doc._attachments;
+    for (var i = 0, len = ignore.length; i < len; i++) {
+      out[ignore[i]] = doc[ignore[i]]
+    }
     return out;
   }
 }

diff --git a/package.json b/package.json
@@ -32,9 +32,9 @@
   "devDependencies": {
     "browserify": "^13.0.0",
     "memdown": "^1.0.0",
-    "pouchdb": "^5.2.1",
+    "pouchdb": "^5.3.1",
     "tap-spec": "^4.1.1",
-    "tape": "^4.4.0",
-    "uglify-js": "^2.4.15"
+    "tape": "^4.5.1",
+    "uglify-js": "^2.6.2"
   }
 }
diff --git a/readme.md b/readme.md
@@ -13,10 +13,10 @@ db.crypto(password).then(function (publicKey) {
 db.removeCrypto(); // will no longer encrypt decrypt your data
 ```
 
-It currently encrypts with the [Chacha20-Poly1305](https://github.com/calvinmetcalf/chacha20poly1305) algorithm, but this may be changed 
+It currently encrypts with the [Chacha20-Poly1305](https://github.com/calvinmetcalf/chacha20poly1305) algorithm, but this may be changed
 to AES256-GCM when Node 0.12.0 drops.
 
-**Note**: Due to performance reasons this module does not encrypt attachments ([#18](https://github.com/calvinmetcalf/crypto-pouch/pull/18))
+**Note**: Attachments cannot be encrypted at this point. Use `{ignore: '_attachments'}` to leave attachments unencrypted. Also note that `db.putAttachment` / `db.getAttachment` are not supported. Use `db.put` and `db.get({binary: true, attachment: true})` instead. ([#18](https://github.com/calvinmetcalf/crypto-pouch/issues/13))
 
 Usage
 -------
@@ -38,15 +38,23 @@ API
 --------
 
 
-### db.crypto(password [, diffieHellman])
+### db.crypto(password [, options])
 
 Set up encryption on the database. Returns a promise.
 
-If the second argument is a string, it is taken to be a Diffie-Hellman ModP group and if a buffer then a prime 
-and the password is interpreted as a Diffie-Hellman public key. If so, the public key 
-for use with the database is returned; you can use that to calculate the shared secret 
+If the second argument is a string, it is taken to be a Diffie-Hellman ModP group and if a buffer then a prime
+and the password is interpreted as a Diffie-Hellman public key. If so, the public key
+for use with the database is returned; you can use that to calculate the shared secret
 which is needed for subsequently opening the data set.
 
+If the second argument is an object:
+
+- `options.modp`  
+  see above
+
+- `options.ignore`  
+  String or Array of Strings of properties that will not be encrypted.  
+
 
 ### db.removeCrypto()
 
@@ -55,22 +63,22 @@ Disables encryption on the database.
 Details
 ===
 
-If you replicate to another database, it will decrypt before sending it to 
-the external one. So make sure that one also has a password set as well if you want 
+If you replicate to another database, it will decrypt before sending it to
+the external one. So make sure that one also has a password set as well if you want
 it encrypted too.
 
-If you change the name of a document, it will throw an error when you try 
-to decrypt it. If you manually move a document from one database to another, 
-it will not decrypt correctly.  If you need to decrypt it a file manually 
-you will find a local doc named `_local/crypto` in the database. This doc has a field 
-named `salt` which is a hex-encoded buffer. Run on your password with that as salt 
-for 1000 iterations to generate a 32 byte (256 bit) key; that is the key 
+If you change the name of a document, it will throw an error when you try
+to decrypt it. If you manually move a document from one database to another,
+it will not decrypt correctly.  If you need to decrypt it a file manually
+you will find a local doc named `_local/crypto` in the database. This doc has a field
+named `salt` which is a hex-encoded buffer. Run on your password with that as salt
+for 1000 iterations to generate a 32 byte (256 bit) key; that is the key
 for decoding documents.
 
-Each document has 3 relevant fields: `data`, `nonce`, and `tag`. 
-`nonce` is the initialization vector to give to chacha20 in addition to the key 
-you generated. Pass the document `_id` as additional authenticated data and the tag 
-as the auth tag and then decrypt the data.  If it throws an error, then you either 
+Each document has 3 relevant fields: `data`, `nonce`, and `tag`.
+`nonce` is the initialization vector to give to chacha20 in addition to the key
+you generated. Pass the document `_id` as additional authenticated data and the tag
+as the auth tag and then decrypt the data.  If it throws an error, then you either
 screwed up or somebody modified the data.
 
 Examples

diff --git a/test.js b/test.js
@@ -139,11 +139,36 @@ test('changes', function (t) {
     t.error(e);
   });
 });
-test('attachments', function (t) {
+test('ignore: _attachments', function (t) {
   t.plan(1);
   var dbName = 'six';
   var db = new PouchDB(dbName, {db: memdown});
-  db.crypto('password').then(function () {
+  db.crypto('password', {ignore: '_attachments'}).then(function () {
+    return db.put({
+      _id: 'id-12345678',
+      _attachments: {
+        'att.txt': {
+          content_type: 'text/plain',
+          data: 'TGVnZW5kYXJ5IGhlYXJ0cywgdGVhciB1cyBhbGwgYXBhcnQKTWFrZS' +
+                'BvdXIgZW1vdGlvbnMgYmxlZWQsIGNyeWluZyBvdXQgaW4gbmVlZA=='
+        }
+      }
+    });
+  }).then(function () {
+    return db.get('id-12345678', {
+      attachments: true,
+      binary: true
+    });
+  }).then(function (doc) {
+    t.ok(Buffer.isBuffer(doc._attachments['att.txt'].data), 'returns _attachments as Buffers');
+  })
+  .catch(t.error);
+})
+test('modp: "modp5", ignore: "_attachments"', function (t) {
+  t.plan(1);
+  var dbName = 'seven';
+  var db = new PouchDB(dbName, {db: memdown});
+  db.crypto('password', {modp: 'modp5', ignore: '_attachments'}).then(function () {
     return db.put({
       _id: 'id-12345678',
       _attachments: {
@@ -153,14 +178,35 @@ test('attachments', function (t) {
                 'BvdXIgZW1vdGlvbnMgYmxlZWQsIGNyeWluZyBvdXQgaW4gbmVlZA=='
         }
       }
-    })
+    });
   }).then(function () {
     return db.get('id-12345678', {
       attachments: true,
       binary: true
-    })
+    });
   }).then(function (doc) {
-    t.ok(Buffer.isBuffer(doc._attachments['att.txt'].data), 'returns _attachtments as Buffers')
+    t.ok(Buffer.isBuffer(doc._attachments['att.txt'].data), 'returns _attachments as Buffers');
+  })
+  .catch(t.error);
+})
+test('throws error when document has attachments', function (t) {
+  t.plan(1);
+  var dbName = 'eight';
+  var db = new PouchDB(dbName, {db: memdown});
+  db.crypto('password').then(function () {
+    return db.put({
+      _id: 'id-12345678',
+      _attachments: {
+        'att.txt': {
+          content_type: 'text/plain',
+          data: 'TGVnZW5kYXJ5IGhlYXJ0cywgdGVhciB1cyBhbGwgYXBhcnQKTWFrZS' +
+                'BvdXIgZW1vdGlvbnMgYmxlZWQsIGNyeWluZyBvdXQgaW4gbmVlZA=='
+        }
+      }
+    });
+  }).then(function () {
+    t.error('does not throw error');
+  }).catch(function (e) {
+    t.ok(/Attachments cannot be encrypted/.test(e.message), 'throws error');
   })
-  .catch(t.error)
 })