[ 
https://issues.apache.org/jira/browse/COUCHDB-1287?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13153936#comment-13153936
 ] 

Jason Smith commented on COUCHDB-1287:
--------------------------------------

Hi, Benoit. No offense intended: as I re-read your patch I think you and I are 
making different features under the same name. The following Bash script 
clarifies my critique. I think you will agree that either (a) we are working on 
different things, with a name collision, "dropbox"; or (b) your patch is 
careless and dangerous.

#!/bin/bash

# Given: admin user "admin" and normal users "amy" and "bob"
# New database
curl -X DELETE http://admin:admin@localhost:5984/db
curl -X PUT http://admin:admin@localhost:5984/db

# Create a document
curl -X PUT http://admin:admin@localhost:5984/db/doc1 -d '{"hello":"world"}'
curl -X PUT http://admin:admin@localhost:5984/db/doc2 -d '{"hello":"world"}'

# Amy is a member. Bob is not.
curl -X PUT http://admin:admin@localhost:5984/db/_security -d 
'{"members":{"names":["amy"]}}'

# Amy can open /db
curl --fail http://amy:amy@localhost:5984/db

# Bob cannot open /db
curl --fail http://bob:bob@localhost:5984/db

# Make a dropbox db
curl -X PUT http://admin:admin@localhost:5984/db/_security -d 
'{"members":{"names":["amy"]}, "dropbox":true}'

# Member amy cannot get a doc (regression)
curl --fail http://amy:amy@localhost:5984/db/doc1

# Non-member bob can get DB metadata (minor breach)
curl --fail http://bob:bob@localhost:5984/db

# Member amy cannot get _all_docs (regression)
curl --fail http://amy:amy@localhost:5984/db/_all_docs

# Non-member bob can fetch the entire database (major breach)
curl --fail http://bob:bob@localhost:5984/db/_changes?include_docs=true

# Anonymous users can fetch the entire database (major breach)
curl --fail http://localhost:5984/db/_changes?include_docs=true
                
> Inbox Database ("write-only" mode)
> ----------------------------------
>
>                 Key: COUCHDB-1287
>                 URL: https://issues.apache.org/jira/browse/COUCHDB-1287
>             Project: CouchDB
>          Issue Type: New Feature
>          Components: HTTP Interface
>    Affects Versions: 1.2
>            Reporter: Jason Smith
>            Priority: Minor
>         Attachments: 
> 0001-handle-dropbox-db.-Add-dropbox-true-to-security-obje.patch, 
> A_0001-Refactor-reader_acl-test-functions-into-a-loop.patch, 
> A_0002-Refactor-the-actual-read-check-out-of-the-member-che.patch, 
> A_0003-Allow-non-member-writes-if-_security.members.allow_a.patch, 
> B_0001-Refactor-reader_acl-test-functions-into-a-loop.patch, 
> B_0002-Refactor-the-actual-read-check-out-of-the-member-che.patch, 
> B_0003-Allow-non-member-updates-if-_security.members.allow_.patch
>
>
> Currently, we can only grant combined read+write access in the _security 
> object "members" section. A user can either do both or neither. This prevents 
> a very common requirement for couch apps: sending private information from 
> less-privileged users to more-privileged users.
> There is no (reasonable) way to make an "inbox" where anybody may create a 
> doc for me, but only I may read it. An inbox database allows user-to-user, or 
> user-to-admin private messages. (Not only chat messages, but asynchronous 
> notifications--with a per-user inbox, perhaps even service requests and 
> responses.)
> There is no reason _security.members (formerly .readers) should control write 
> access. validate_doc_update() functions do this better.
> I propose a boolean flag, _security.members.allow_anonymous_writes. If it is 
> true, then CouchDB will allow document updates from non-members, giving 
> validate_doc_update() the final word on accepting or rejecting the update.
> Requirements:
> 1. Everything about _security stays the same (backward-compatible)
> 2. If members.allow_anonymous_writes === true, then most PUT and POSTs may 
> proceed
> 3. All updates are still subject to approval by all validate_doc_update 
> functions, same as before.
> These are the known changes to the security model. I consider these all to be 
> either very unlikely in practice, or worth the trade-off.
> * If you write to an inbox DB, you know, for a time, a subset of its 
> documents (but that's the point)
> * An _update function could reveal a document to the user, with or without 
> changing it. However, an admin must install such a misguided update function.
> * You can launch timing attacks to learn information about validate_doc_update
>   * You might discover whether doc IDs exist in the DB or not
>   * You might discover a well-known open source validation function. You can 
> look for bugs in its source code.
> * Zero or more things which Jason can't think of

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: 
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to