[Gluster-devel] Change in glusterfs[master]: Transparent data encryption and metadata authentication in t...

[Anand Avati]

Edward,
It looks like this patch requires a higher version of openssl (I recall 
you have mentioned before that that dependency was on version 1.0.1c? I 
checked yum update on the build server and the latest available version 
is 1.0.0-27. Is there a "clean" way to get the right version of openssl 
to a RHEL/CENTOS-6.x server?

Also note that the previous submission of the patch was at 
http://review.gluster.org/4667. The recent on 
(http://review.gluster.org/6086) has a different Change-Id: in the 
commit log. It will be good if you can re-submit the patch with the old 
Change-Id (and abandon #6086) so that we can maintain the history of 
resubmission and the old work on records.

Thanks!
Avati

On 10/14/2013 07:26 AM, Edward Shishkin (Code Review) wrote:
> Edward Shishkin has uploaded a new change for review.
>
>    http://review.gluster.org/6086
>
>
> Change subject: Transparent data encryption and metadata authentication in the systems with non-trusted server (take II)
> ......................................................................
>
> Transparent data encryption and metadata authentication
> in the systems with non-trusted server (take II)
>
> This new functionality can be useful in various cloud technologies.
> It is implemented via a special encryption/crypt translator, which
> works on the client side and performs encryption and authentication;
>
>                1. Class of supported algorithms
>
> The crypt translator can support any atomic symmetric block cipher
> algorithms (which require to pad plain/cipher text before performing
> encryption/decryption transform (see glossary in atom.c for
> definitions). In particular, it can support algorithms with the EOF
> issue (which require to pad the end of file by extra-data).
>
> Crypt translator performs translations
> user -> (offset, size) -> (aligned-offset, padded-size) ->server
> (and backward), and resolves individual FOPs (write(), truncate(),
> etc) to read-modify-write sequences.
>
> A volume can contain files encrypted by different algorithms of the
> mentioned class. To change some option value just reconfigure the
> volume.
>
> Currently only one algorithm is supported: AES_XTS.
>
> Example of algorithms, which can not be supported by the crypt
> translator:
>
> 1. Asymmetric block cipher algorithms, which inflate data, e.g. RSA;
> 2. Symmetric block cipher algorithms with inline MACs for data
>     authentication.
>
>                     2. Implementation notes.
>
> a) Atomic algorithms
>
> Since any process in a stackable file system manipulates with local
> data (which can be obsoleted by local data of another process), any
> atomic cipher algorithm without proper support can lead to non-POSIX
> behavior. To resolve the "collisions" we introduce locks: before
> performing FOP->read(), FOP->write(), etc. the process should first
> lock the file.
>
> b) Algorithms with EOF issue
>
> Such algorithms require to pad the end of file with some extra-data.
> Without proper support this will result in losing information about
> real file size. Keeping a track of real file size is a responsibility
> of the crypt translator. A special extended attribute with the name
> "trusted.glusterfs.crypt.att.size" is used for this purpose. All files
> contained in bricks of encrypted volume do have "padded" sizes.
>
>                    3. Non-trusted servers and
>                       Metadata authentication
>
> We assume that server, where user's data is stored on is non-trusted.
> It means that the server can be subjected to various attacks directed
> to reveal user's encrypted personal data. We provide protection
> against such attacks.
>
> Every encrypted file has specific private attributes (cipher algorithm
> id, atom size, etc), which are packed to a string (so-called "format
> string") and stored as a special extended attribute with the name
> "trusted.glusterfs.crypt.att.cfmt". We protect the string from
> tampering. This protection is mandatory, hardcoded and is always on.
> Without such protection various attacks (based on extending the scope
> of per-file secret keys) are possible.
>
> Our authentication method has been developed in tight collaboration
> with Red Hat security team and is implemented as "metadata loader of
> version 1" (see file metadata.c). This method is NIST-compliant and is
> based on checking 8-byte per-hardlink MACs created(updated) by
> FOP->create(), FOP->link(), FOP->unlink(), FOP->rename() by the
> following unique entities:
>
> . file (hardlink) name;
> . verified file's object id (gfid).
>
> Every time, before manipulating with a file, we check it's MACs at
> FOP->open() time. Some FOPs don't require a file to be opened (e.g.
> FOP->truncate()). In such cases the crypt translator opens the file
> mandatory.
>
>                          4. Generating keys
>
> Unique per-file keys are derived by NIST-compliant methods from the
>
> a) parent key;
> b) unique verified object-id of the file (gfid);
> Per-volume master key, provided by user at mount time is in the root
> of this "tree of keys".
>
> Those keys are used to:
>
> 1) encrypt/decrypt file data;
> 2) encrypt/decrypt file metadata;
> 3) create per-file and per-link MACs for metadata authentication.
>
>                            5. Instructions
>                   Getting started with crypt translator
>
> Example:
>
> 1) Create a volume "myvol" by specifying the option "encrypt":
>
>     # gluster volume create myvol encrypt pepelac:/vols/xvol
>
> 2) Set location (absolute pathname) of your master key:
>
>     # gluster volume set myvol encryption.master-key /home/me/mykey
>
> 3) Set other options to override default options, if needed.
>
> 4) On the client side make sure that the file /home/me/mykey exists
>     and contains proper per-volume master key (that is 256-bit AES
>     key). This key has to be in hex form, i.e. should be represented
>     by 64 symbols from the set  {'0', ..., '9', 'a', ..., 'f'}.
>     The key should start at the beginning of the file. All symbols at
>     offsets >= 64 are ignored.
>
> 5) Mount the volume "myvol" on the client side:
>
>     # glusterfs --volfile-server=pepelac --volfile-id=myvol /mnt
>
>     After successful mount the file which contains master key may be
>     removed. NOTE: Keeping the master key between mount sessions is in
>     user's competence.
>
> **********************************************************************
>
> WARNING! Losing the master key will make content of all regular files
> inaccessible. Mount with improper master key allows to access content
> of directories: file names are not encrypted.
>
> **********************************************************************
>
>                 6. Options of crypt translator
>
> 1) "master-key": specifies location (absolute pathname) of the file
>     which contains per-volume master key. There is no default location
>     for master key.
>
> 2) "data-key-size": specifies size of per-file key for data encryption
>     Possible values:
>     . "256" default value
>     . "512"
>
> 3) "block-size": specifies atom size. Possible values:
>     . "512"
>     . "1024"
>     . "2048"
>     . "4096" default value;
>
>                         7. Test cases
>
> Any workload, which involves the following file operations:
>
> ->create();
> ->open();
> ->readv();
> ->writev();
> ->truncate();
> ->ftruncate();
> ->link();
> ->unlink();
> ->rename();
> ->readdirp().
>
>                          8. TODOs:
>
> 1) Currently size of IOs issued by crypt translator is restricted
>     by block_size (4K by default). We can use larger IOs to improve
>     performance.
>
> Change-Id: Idc3523a8752888d3dd10f4fe71aa38dfc53d9ded
> Signed-off-by: Edward Shishkin <edward at redhat.com>
> ---
> M cli/src/cli-cmd-parser.c
> M configure.ac
> M doc/gluster.8
> M libglusterfs/src/gf-dirent.c
> M libglusterfs/src/gf-dirent.h
> M xlators/cluster/dht/src/dht-common.c
> M xlators/encryption/Makefile.am
> A xlators/encryption/crypt/Makefile.am
> A xlators/encryption/crypt/src/Makefile.am
> A xlators/encryption/crypt/src/atom.c
> A xlators/encryption/crypt/src/crypt-common.h
> A xlators/encryption/crypt/src/crypt-mem-types.h
> A xlators/encryption/crypt/src/crypt.c
> A xlators/encryption/crypt/src/crypt.h
> A xlators/encryption/crypt/src/data.c
> A xlators/encryption/crypt/src/keys.c
> A xlators/encryption/crypt/src/metadata.c
> A xlators/encryption/crypt/src/metadata.h
> M xlators/mgmt/glusterd/src/glusterd-store.c
> M xlators/mgmt/glusterd/src/glusterd-store.h
> M xlators/mgmt/glusterd/src/glusterd-volgen.c
> M xlators/mgmt/glusterd/src/glusterd-volume-ops.c
> M xlators/mgmt/glusterd/src/glusterd-volume-set.c
> M xlators/mgmt/glusterd/src/glusterd.h
> M xlators/protocol/client/src/client-rpc-fops.c
> 25 files changed, 8,733 insertions(+), 28 deletions(-)
>
>
>    git pull ssh://git.gluster.org/glusterfs refs/changes/86/6086/1
>