--- begin forwarded text To: theory and practice of decentralized computer networks <p2p-hackers@lists.zooko.com>, tahoe-dev@allmydata.org, "General discussions concerning capability systems." <cap-talk@mail.eros-os.org> From: Zooko O'Whielacronx <zooko@zooko.com> Date: Fri, 29 Jun 2007 18:16:25 -0600 Subject: [p2p-hackers] announcing Allmydata-Tahoe v0.4 Reply-To: theory and practice of decentralized computer networks <p2p-hackers@lists.zooko.com> Sender: p2p-hackers-bounces@lists.zooko.com <x-flowed>NEW VERSION RELEASED We are pleased to announce the release of version 0.4 of Allmydata- Tahoe, a secure, decentralized storage grid under a free-software licence. This is the follow-up to v0.3 which was released June 6, 2007 (see [1]). Since then we've made several improvements, including: * Add encrypted, mutable directories, so that you can organize your files into directories, change the contents of directories, and share your directories with your friends, without thereby sharing your directories with anyone else -- not even with the owners of the servers that host your directories. * make it so that web browsers can connect to the Tahoe node securely with https (ticket #55) For complete details, see this web page which shows all ticket changes, repository checkins, and wiki changes from June 11 to today, June 29: [2]. Allmydata-Tahoe v0.4 is incompatible with v0.3 due to the new encrypted directory structure, among other things. (Note that this applies only to directories -- individual files uploaded with v0.3 are probably downloadable with v0.4.) WHAT IS IT GOOD FOR? The source code that we are releasing is the current working prototype for Allmydata's next-generation product. This release is targeted at hackers and users who are willing to use a minimal, text-oriented web user interface. This software is not yet recommended for storage of highly confidential data nor for important data which is not otherwise backed up, but it is useful for experimentation, prototyping, and extension. This release of Allmydata-Tahoe is suitable for Use Case #2: "groups of friends who want to share backup and file-sharing" (see the wiki page "UseCases": [3]). It is easy to set up a private grid which is securely shared among a specific, limited set of friends. Files uploaded to this shared grid will be available to all friends, even when some of the computers are unavailable. It is also easy to use a public grid, but to encrypt individual files and directories so that only intended recipients can read them. LICENCE Tahoe is offered under the GNU General Public License (v2 or later), with the added permission that, if you become obligated to release a derived work under this licence (as per section 2.b), you may delay the fulfillment of this obligation for up to 12 months. INSTALLATION This release of Tahoe works on Linux/x86, Linux/amd64, Mac/Intel, Mac/ PPC, Windows-native, and Cygwin. To install, download the tarball [4], untar it, go into the resulting directory, and follow the directions in the README [5]. USAGE Once installed, create a "client node". Instruct this client node to connect to a specific "introducer node" by means of config files in the client node's working directory. To join a public grid, copy in the .furl files for that grid. To create a private grid, run your own introducer, and copy its .furl files. See the README for step-by-step instructions. Each client node runs a local webserver (enabled by writing the desired port number into a file called 'webport'). The front page of this webserver shows the node's status, including which introducer is being used and which other nodes are connected. Links from the status page lead to others that give access to a shared virtual filesystem, in which each directory is represented by a separate page. Each client node also has a separate (non-shared) virtual filesystem. Each directory page shows a list of the files available there, with download links, and forms to upload new files. Other ways to access the filesystem are planned: please see the roadmap.txt [6] for some rough details. HACKING AND COMMUNITY Please join the mailing list [7] to discuss the ideas behind Tahoe and extensions of and uses of Tahoe. Patches that extend and improve Tahoe are gratefully accepted -- roadmap.txt shows the next improvements that we plan to make and CREDITS lists the names of people who've contributed to the project. You can browse the revision control history, source code, and issue tracking at the Trac instance [8]. Please see the buildbot [9], which shows how Tahoe builds and passes unit tests on each checkin, and the code coverage results [10] and percentage-covered graph [11], which show how much of the Tahoe source code is currently exercised by the test suite. NETWORK ARCHITECTURE Each peer maintains a connection to each other peer. A single distinct server called an "introducer" is used to discover other peers with which to connect. To store a file, the file is encrypted and erasure coded, and each resulting share is uploaded to a different peer. The secure hash of the encrypted file and the encryption key are packed into a URI, knowledge of which is necessary and sufficient to recover the file. To fetch a file, starting with the URI, a subset of shares is downloaded from peers, the file is reconstructed from the shares, and then decrypted. A single distinct server called a "vdrive server" maintains a global mapping from pathnames/filenames to URIs. We are acutely aware of the limitations of decentralization and scalability inherent in this version. In particular, the completely-connected property of the grid and the requirement of a single distinct introducer and vdrive server limits the possible size of the grid. We have plans to loosen these limitations (see roadmap.txt). Currently it should be noted that the grid already depends as little as possible on the accessibility and correctness of the introduction server and the vdrive server. Also note that the choice of which servers to use is easily configured -- you should be able to set up a private grid for you and your friends almost as easily as to connect to our public test grid. SOFTWARE ARCHITECTURE Tahoe is a "from the ground-up" rewrite, inspired by Allmydata's existing consumer backup service. It is primarily written in the Python programming language. Tahoe is based on the Foolscap library [12] which provides a remote object protocol inspired by the capability-secure "E" programming language [13]. Foolscap allows us to express the intended behavior of the distributed grid directly in object-oriented terms while relying on a well-engineered, secure transport layer. The network layer is provided by the Twisted library [14]. Computationally intensive operations are performed in native compiled code, such as the "zfec" library for fast erasure coding (also available separately: [15]). Tahoe is sponsored by Allmydata, Inc. [16], a provider of consumer backup services. Allmydata, Inc. contributes hardware, software, ideas, bug reports, suggestions, demands, and money (employing several Allmydata- Tahoe hackers and allowing them to spend part of their work time on the next-generation, free-software project). We are eternally grateful! Zooko O'Whielacronx and Brian Warner on behalf of the Allmydata-Tahoe team June 29, 2007 Boulder, Colorado and San Francisco, California [1] http://allmydata.org/trac/tahoe/timeline? from=2007-06-29&daysback=17&changeset=on&ticket=on&wiki=on&update=Update [3] http://allmydata.org/trac/tahoe/wiki/UseCases [4] http://allmydata.org/source/tahoe/tahoe-0.4.tar.gz [5] http://allmydata.org/trac/tahoe/browser/README?rev=844 [6] http://allmydata.org/trac/tahoe/browser/roadmap.txt [7] http://allmydata.org/cgi-bin/mailman/listinfo/tahoe-dev [8] http://allmydata.org/trac/tahoe [9] http://allmydata.org/buildbot [10] http://allmydata.org/tahoe-figleaf/figleaf/ [11] http://allmydata.org/tahoe-figleaf-graph/hanford.allmydata.com- tahoe_figleaf.html [12] http://twistedmatrix.com/trac/wiki/FoolsCap [13] http://erights.org/ [14] http://twistedmatrix.com/ [15] http://allmydata.org/trac/tahoe/browser/src/zfec [16] http://allmydata.com _______________________________________________ p2p-hackers mailing list p2p-hackers@lists.zooko.com http://lists.zooko.com/mailman/listinfo/p2p-hackers </x-flowed> --- end forwarded text -- ----------------- R. 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