amcrypt-ossl-asym(8) [debian man page]

AMCRYPT-OSSL-ASYM(8)					  System Administration Commands				      AMCRYPT-OSSL-ASYM(8)

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/

Amanda 3.3.1							    02/21/2012						      AMCRYPT-OSSL-ASYM(8)

Check Out this Related Man Page

PKEY(1) 							      OpenSSL								   PKEY(1)

NAME

       pkey - public or private key processing tool

SYNOPSIS

       openssl pkey [-inform PEM|DER] [-outform PEM|DER] [-in filename] [-passin arg] [-out filename] [-passout arg] [-cipher] [-text] [-text_pub]
       [-noout] [-pubin] [-pubout] [-engine id]

DESCRIPTION

       The pkey command processes public or private keys. They can be converted between various forms and their components printed out.

COMMAND OPTIONS

       -inform DER|PEM
	   This specifies the input format DER or PEM.

       -outform DER|PEM
	   This specifies the output format, the options have the same meaning as the -inform option.

       -in filename
	   This specifies the input filename to read a key from or standard input if this option is not specified. If the key is encrypted a pass
	   phrase will be prompted for.

       -passin arg
	   the input file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).

       -out filename
	   This specifies the output filename to write a key to or standard output if this option is not specified. If any encryption options are
	   set then a pass phrase will be prompted for. The output filename should not be the same as the input filename.

       -passout password
	   the output file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).

       -cipher
	   These options encrypt the private key with the supplied cipher. Any algorithm name accepted by EVP_get_cipherbyname() is acceptable
	   such as des3.

       -text
	   prints out the various public or private key components in plain text in addition to the encoded version.

       -text_pub
	   print out only public key components even if a private key is being processed.

       -noout
	   do not output the encoded version of the key.

       -pubin
	   by default a private key is read from the input file: with this option a public key is read instead.

       -pubout
	   by default a private key is output: with this option a public key will be output instead. This option is automatically set if the input
	   is a public key.

       -engine id
	   specifying an engine (by its unique id string) will cause pkey to attempt to obtain a functional reference to the specified engine,
	   thus initialising it if needed. The engine will then be set as the default for all available algorithms.

EXAMPLES

       To remove the pass phrase on an RSA private key:

	openssl pkey -in key.pem -out keyout.pem

       To encrypt a private key using triple DES:

	openssl pkey -in key.pem -des3 -out keyout.pem

       To convert a private key from PEM to DER format:

	openssl pkey -in key.pem -outform DER -out keyout.der

       To print out the components of a private key to standard output:

	openssl pkey -in key.pem -text -noout

       To print out the public components of a private key to standard output:

	openssl pkey -in key.pem -text_pub -noout

       To just output the public part of a private key:

	openssl pkey -in key.pem -pubout -out pubkey.pem

SEE ALSO

       genpkey(1), rsa(1), pkcs8(1), dsa(1), genrsa(1), gendsa(1)

1.0.1e								    2013-02-11								   PKEY(1)

Linux and UNIX Man Pages

amcrypt-ossl-asym(8) [debian man page]

Check Out this Related Man Page