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Annotation of src/usr.bin/ssh/ssh-keygen.1, Revision 1.1

1.1     ! deraadt     1: .\"  -*- nroff -*-
        !             2: .\"
        !             3: .\" ssh-keygen.1
        !             4: .\"
        !             5: .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
        !             6: .\"
        !             7: .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
        !             8: .\"                    All rights reserved
        !             9: .\"
        !            10: .\" Created: Sat Apr 22 23:55:14 1995 ylo
        !            11: .\"
        !            12: .\" $Id: ssh-keygen.1,v 1.2 1999/05/04 11:59:16 bg Exp $
        !            13: .\"
        !            14: .TH SSH-KEYGEN 1 "November 8, 1995" "SSH" "SSH"
        !            15:
        !            16: .SH NAME
        !            17: ssh-keygen \- authentication key generation
        !            18:
        !            19: .SH SYNOPSIS
        !            20: .LP
        !            21: .B ssh-keygen
        !            22: [\c
        !            23: .BI \-b \ bits\c
        !            24: ]
        !            25: [\c
        !            26: .BI \-N \ new_passphrase\c
        !            27: ]
        !            28: [\c
        !            29: .BI \-C \ comment\c
        !            30: ]
        !            31:
        !            32: .B "ssh-keygen \-p
        !            33: [\c
        !            34: .BI \-P \ old_passphrase\c
        !            35: ]
        !            36: [\c
        !            37: .BI \-N \ new_passphrase\c
        !            38: ]
        !            39:
        !            40: .B "ssh-keygen \-c
        !            41: [\c
        !            42: .BI \-P \ passphrase\c
        !            43: ]
        !            44: [\c
        !            45: .BI \-C \ comment\c
        !            46: ]
        !            47:
        !            48: .SH DESCRIPTION
        !            49: .LP
        !            50: .B Ssh-keygen
        !            51: generates and manages authentication keys for
        !            52: .BR ssh (1).
        !            53: Normally each user wishing to use
        !            54: .B ssh
        !            55: with RSA authentication runs this once to create the authentication
        !            56: key in
        !            57: .IR \&$HOME/\s+2.\s0ssh/identity ".
        !            58: Additionally, the system administrator may use this to generate host keys.
        !            59: .LP
        !            60: Normally this program generates the key and asks for a file in which
        !            61: to store the private key.  The public key is stored in a file with the
        !            62: same name but ".pub" appended.  The program also asks for a
        !            63: passphrase.  The passphrase may be empty to indicate no passphrase
        !            64: (host keys must have empty passphrase), or it may be a string of
        !            65: arbitrary length.  Good passphrases are 10-30 characters long and are
        !            66: not simple sentences or otherwise easily guessable (English
        !            67: prose has only 1-2 bits of entropy per word, and provides very bad
        !            68: passphrases).  The passphrase can be changed later by using the
        !            69: .B \-p
        !            70: option.
        !            71: .LP
        !            72: There is no way to recover a lost passphrase.  If the passphrase is
        !            73: lost or forgotten, you will have to generate a new key and copy the
        !            74: corresponding public key to other machines.
        !            75: .LP
        !            76: There is also a comment field in the key file that is only for
        !            77: convenience to the user to help identify the key.  The comment can
        !            78: tell what the key is for, or whatever is useful.  The comment is
        !            79: initialized to user@host when the key is created, but can be changed
        !            80: using the
        !            81: .B \-c
        !            82: option.
        !            83:
        !            84: .SH OPTIONS
        !            85: .TP 0.6i
        !            86: .BI \-b \ bits
        !            87: Specifies the number of bits in the key to create.  Minimum is 512
        !            88: bits.  Generally 1024 bits is considered sufficient, and key sizes
        !            89: above that no longer improve security but make things slower.  The
        !            90: default is 1024 bits.
        !            91: .TP
        !            92: .B \-c
        !            93: Requests changing the comment in the private and public key files.
        !            94: The program will prompt for the file containing the private keys, for
        !            95: passphrase if the key has one, and for the new comment.
        !            96: .TP
        !            97: .B \-p
        !            98: Requests changing the passphrase of a private key file instead of
        !            99: creating a new private key.  The program will prompt for the file
        !           100: containing the private key, for the old passphrase, and twice for the
        !           101: new passphrase.
        !           102: .TP
        !           103: .B \-C
        !           104: Provides the new comment.
        !           105: .TP
        !           106: .B \-N
        !           107: Provides the new passphrase.
        !           108: .TP
        !           109: .B \-P
        !           110: Provides the (old) passphrase.
        !           111:
        !           112: .SH FILES
        !           113: .TP 0.6i
        !           114: .I \&$HOME/\s+2.\s0ssh/random_seed
        !           115: Used for seeding the random number generator.  This file should not be
        !           116: readable by anyone but the user.  This file is created the first time
        !           117: the program is run, and is updated every time.
        !           118: .TP
        !           119: .I \&$HOME/\s+2.\s0ssh/identity
        !           120: Contains the RSA authentication identity of the user.  This file
        !           121: should not be readable by anyone but the user.  It is possible to
        !           122: specify a passphrase when generating the key; that passphrase will be
        !           123: used to encrypt the private part of this file using IDEA.  This file
        !           124: is not automatically accessed by
        !           125: .BR ssh-keygen ",
        !           126: but it is offered as the default file for the private key.
        !           127: .TP
        !           128: .I \&$HOME/\s+2.\s0ssh/identity.pub
        !           129: Contains the public key for authentication.  The contents of this file
        !           130: should be added to \f4$HOME/\s+2.\s0ssh/authorized_keys\f1 on all machines
        !           131: where you wish to log in using RSA authentication.  There is no
        !           132: need to keep the contents of this file secret.
        !           133:
        !           134: .SH AUTHOR
        !           135: .LP
        !           136: Tatu Ylonen <ylo@cs.hut.fi>
        !           137:
        !           138: .SH SEE ALSO
        !           139: .LP
        !           140: .BR ssh (1),
        !           141: .BR sshd (8),
        !           142: .BR ssh-agent (1),
        !           143: .BR ssh-add (1)