ssh-keyconver(1)

NAME

ssh-keyconvert - convert ssh v1 keys and authorization files

SYNOPSIS

ssh-keyconvert [-k] [-o output_file] identity_file ...
ssh-keyconvert  [-a] [-o output_file] authorization_file ...

DESCRIPTION

ssh-keyconvert converts RSA public and private keys used for

public key
based user authentication with protocol version 1 to the

format used with
protocol version 2.

When using RSA user authentication with SSH protocol version

1, the
client uses the private key from $HOME/.ssh/identity to pro

vide its iden
tity to the server. The server grants or denies access based

on whether
the public part of this key is listed in

$HOME/.ssh/authorized_keys.

SSH protocol version 2 supports both DSA and RSA keys, but

the way RSA
keys are stored are differently. On the client, the default

file name is
.ssh/id_rsa rather than .ssh/identity, and the file's format

is different
as well. On the server, the public porting of the key can

still be stored
in .ssh/authorized_keys, but the key notation has changed as

well.
Therefore, when switching from protocol version 1 to version

2, you
either have to create a new identity key using ssh-keygen(1)

and add that
key to the server's authorized_keys file, or you need to

convert your
keys using ssh-keyconvert.

By default, ssh-keyconvert will try to guess the type of

file that is to
be converted. If it fails to guess correctly, you can tell

if what type
of conversion to perform by specifying the -k option to con

vert the pri
vate key, or the -a option to convert an authorisation file.

When converting your private keys stored in .ssh/identity,

ssh-keyconvert
will read the private key, prompting you for the pass phrase

if the key
is protected by a pass phrase. If the -o option is given, it

will write
the private key to the specified file, using version 2 syn

tax. If the key
was protected by a pass phrase, it will use the same pass

phrase to pro
tect the new file. It will also write the public portion of

the key to a
second file, using the specified file name with ``.pub'' ap

pended. If
the -o option was not given, private and public key will be

written to
id_rsa and id_rsa.pub, respectively, relative to the direc

tory of the
input key file.

If the destination file already exists, ssh-keyconvert will

prompt the
user for confirmation before overwriting the file, unless

the -f option
is given.

When converting your authorized_keys file, ssh-keyconvert

will ignore any
keys in SSH version 2 format. Any public keys in version 1

format will be
converted and appended to the output file using the new syn

tax. If the -o
option is given, keys are appended to the specified file. If

it is not
given, ssh-keyconvert will append all keys to the input

file.

Note that ssh-keyconvert does not check for duplicate keys,

so if you run
it on .ssh/authorized_keys more several times, the converted

keys will
show up several times.

OPTIONS

-k Convert private key file(s). The default is to guess

the type of

file that should be converted.

-a Convert authorized_keys file(s). The default is to

guess the type

of file that should be converted.

-o outfile

Specify the name of the output file. When convert

ing an autho
rization file, all public keys will be appended to

this file.
For private key conversion, the private and public

components of
the key will be stored in outfile and outfile.pub,

respectively.
Note that since every key must be stored in a sepa

rate file, you
cannot use this option when you specify several in

put files.

-f When converting a key file, and the output file al

ready exists,

ssh-keyconvert will ask the user whether to over

write the file.
Using this option forces overwriting.

AUTHORS

OpenSSH is a derivative of the original and free ssh 1.2.12

release by
Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels

Provos, Theo
de Raadt and Dug Song removed many bugs, re-added newer fea

tures and cre
ated OpenSSH. ssh-keyconvert was contributed by Olaf Kirch.

SEE ALSO

ssh(1), ssh-add(1), ssh-agent(1), sshd(8)

J. Galbraith and R. Thayer, SECSH Public Key File Format,

draft-ietfsecsh-publickeyfile-01.txt, March 2001, work in progress ma

terial.

BSD February 2, 2002

BSD