Encrypting Backups¶
Percona XtraBackup supports encrypting and decrypting local and streaming
backups with xbstream option adding another layer of protection. The
encryption is implemented using the libgcrypt library from GnuPG.
Creating Encrypted Backups¶
To make an encrypted backup the following options need to be specified (options
--encrypt-key and --encrypt-key-file are mutually exclusive,
i.e. just one of them needs to be provided):
-
--encrypt -
--encrypt-key -
--encrypt-key-file
Both the --encrypt-key option and
--encrypt-key-file option can be used to specify the
encryption key. An encryption key can be generated with a command like
openssl rand -base64 32
Example output of that command should look like this:
U2FsdGVkX19VPN7VM+lwNI0fePhjgnhgqmDBqbF3Bvs=
This value then can be used as the encryption key
The --encrypt-key Option¶
Example of the xtrabackup command using the --encrypt-key should
look like this:
$ xtrabackup --backup --encrypt=AES256 --encrypt-key="U2FsdGVkX19VPN7VM+lwNI0fePhjgnhgqmDBqbF3Bvs=" --target-dir=/data/backup
The --encrypt-key-file Option¶
Use the --encrypt-key-file option as follows:
$ xtrabackup --backup --encrypt=AES256 --encrypt-key-file=/data/backups/keyfile --target-dir=/data/backup
Note
Depending on the text editor that you use to make the KEYFILE,
the editor can automatically insert the CRLF (end of line)
character. This will cause the key size to grow and thus making it
invalid. The suggested way to create the file is by using the
command line: echo -n “U2FsdGVkX19VPN7VM+lwNI0fePhjgnhgqmDBqbF3Bvs=” > /data/backups/keyfile.
Optimizing the encryption process¶
Two new options are available for encrypted backups that can be used to speed up
the encryption process. These are --encrypt-threads and
--encrypt-chunk-size. By using the --encrypt-threads option
multiple threads can be specified to be used for encryption in parallel. Option
--encrypt-chunk-size can be used to specify the size (in bytes) of the
working encryption buffer for each encryption thread (default is 64K).
Decrypting Encrypted Backups¶
Backups can be decrypted with The xbcrypt binary. The following one-liner can be used to encrypt the whole folder:
$ for i in `find . -iname "*\.xbcrypt"`; do xbcrypt -d --encrypt-key-file=/root/secret_key --encrypt-algo=AES256 < $i > $(dirname $i)/$(basename $i .xbcrypt) && rm $i; done
Percona XtraBackup --decrypt option has been implemented that can be
used to decrypt the backups:
$ xtrabackup --decrypt=AES256 --encrypt-key="U2FsdGVkX19VPN7VM+lwNI0fePhjgnhgqmDBqbF3Bvs=" --target-dir=/data/backup/
Percona XtraBackup doesn’t automatically remove the encrypted files. In order
to clean up the backup directory users should remove the \*.xbcrypt
files.
Note
--parallel can be used with --decrypt option to decrypt multiple files simultaneously.
When the files are decrypted, the backup can be prepared.
Preparing Encrypted Backups¶
After the backups have been decrypted, they can be prepared in the same way as
the standard full backups with the --prepare option:
$ xtrabackup --prepare --target-dir=/data/backup/
Restoring Encrypted Backups¶
xtrabackup offers the --copy-back option to restore a backup to the
server’s datadir:
$ xtrabackup --copy-back --target-dir=/data/backup/
It will copy all the data-related files back to the server’s datadir,
determined by the server’s my.cnf configuration file. You should check
the last line of the output for a success message:
150318 11:08:13 xtrabackup: completed OK!