Provided by: amanda-common_3.3.6-4.1_i386 bug

NAME

       amcrypt-ossl-asym - crypt program for Amanda asymmetric data encryption
       using OpenSSL

SYNOPSIS

       amcrypt-ossl-asym [-d]

DESCRIPTION

       amcrypt-ossl-asym uses OpenSSL to encrypt and decrypt data. OpenSSL is
       available from www.openssl.org. OpenSSL offers a wide variety of cipher
       choices ( amcrypt-ossl-asym defaults to 256-bit AES) and can use
       hardware cryptographic accelerators on several platforms.

       amcrypt-ossl-asym will search for the OpenSSL program in the following
       directories:
       /bin:/usr/bin:/usr/local/bin:/usr/ssl/bin:/usr/local/ssl/bin.

GENERATING PUBLIC AND PRIVATE KEYS

       RSA keys can be generated with the standard OpenSSL commands, e.g.:
       $ cd /var/lib/amanda
       $ openssl genrsa -aes128 -out backup-privkey.pem 1024
       Generating RSA private key, 1024 bit long modulus
       [...]
       Enter pass phrase for backup-privkey.pem: ENTER YOUR PASS PHRASE
       Verifying - Enter pass phrase for backup-key.pem: ENTER YOUR PASS PHRASE

       $ openssl rsa -in backup-privkey.pem -pubout -out backup-pubkey.pem
       Enter pass phrase for backup-privkey.pem: ENTER YOUR PASS PHRASE
       Writing RSA key

       To generate a private key without a passphrase, omit the -aes128
       option. See openssl_genrsa(1) for more key generation options.

       Note that it is always possible to generate the public key from the
       private key.

KEY AND PASSPHRASE MANAGEMENT

       amcrypt-ossl-asym uses the public key to encrypt data. The security of
       the data does not depend on the confidentiality of the public key. The
       private key is used to decrypt data, and must be protected. Encrypted
       backup data cannot be recovered without the private key. The private
       key may optionally be encrypted with a passphrase.

       While the public key must be online at all times to perorm backups, the
       private key and optional passphrase are only needed to restore data. It
       is recommended that the latter be stored offline all other times. For
       example, you could keep the private key on removable media, and copy it
       into place for a restore; or you could keep the private key online,
       encrypted with a passphrase that is present only for a restore.

       OpenSSL's key derivation routines use a salt to guard against
       dictionary attacks on the pass phrase; still it is important to pick a
       pass phrase that is hard to guess. The Diceware method (see
       www.diceware.com) can be used to create passphrases that are difficult
       to guess and easy to remember.

FILES

       /var/lib/amanda/backup-privkey.pem
           File containing the RSA private key. It should not be readable by
           any user other than the Amanda user.

       /var/lib/amanda/backup-pubkey.pem
           File containing the RSA public key.

       /var/lib/amanda/.am_passphrase
           File containing the passphrase. It should not be readable by any
           user other than the Amanda user.

SEE ALSO

       amanda(8), amanda.conf(5), openssl(1), amcrypt-ossl(8)

       The Amanda Wiki: : http://wiki.zmanda.com/

AUTHOR

       Kevin Till <kevin.till@zmanda.com>
           Zmanda, Inc. (http://www.zmanda.com)

NOTES

        1. www.openssl.org
           http://www.openssl.org/

        2. www.diceware.com
           http://www.diceware.com/