Annotation of src/usr.bin/ssh/ssh-keygen.1, Revision 1.100
1.100 ! naddy 1: .\" $OpenBSD: ssh-keygen.1,v 1.99 2010/08/31 11:54:45 djm Exp $
1.29 niklas 2: .\"
1.1 deraadt 3: .\" -*- nroff -*-
4: .\"
5: .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
6: .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7: .\" All rights reserved
8: .\"
1.22 deraadt 9: .\" As far as I am concerned, the code I have written for this software
10: .\" can be used freely for any purpose. Any derived versions of this
11: .\" software must be clearly marked as such, and if the derived work is
12: .\" incompatible with the protocol description in the RFC file, it must be
13: .\" called by a name other than "ssh" or "Secure Shell".
14: .\"
15: .\"
1.33 deraadt 16: .\" Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
17: .\" Copyright (c) 1999 Aaron Campbell. All rights reserved.
18: .\" Copyright (c) 1999 Theo de Raadt. All rights reserved.
1.22 deraadt 19: .\"
20: .\" Redistribution and use in source and binary forms, with or without
21: .\" modification, are permitted provided that the following conditions
22: .\" are met:
23: .\" 1. Redistributions of source code must retain the above copyright
24: .\" notice, this list of conditions and the following disclaimer.
25: .\" 2. Redistributions in binary form must reproduce the above copyright
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1.1 deraadt 28: .\"
1.22 deraadt 29: .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30: .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31: .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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1.1 deraadt 39: .\"
1.100 ! naddy 40: .Dd $Mdocdate: August 31 2010 $
1.2 deraadt 41: .Dt SSH-KEYGEN 1
42: .Os
43: .Sh NAME
44: .Nm ssh-keygen
1.37 markus 45: .Nd authentication key generation, management and conversion
1.2 deraadt 46: .Sh SYNOPSIS
1.97 schwarze 47: .Bk -words
1.2 deraadt 48: .Nm ssh-keygen
1.25 markus 49: .Op Fl q
1.2 deraadt 50: .Op Fl b Ar bits
1.53 stevesk 51: .Fl t Ar type
1.2 deraadt 52: .Op Fl N Ar new_passphrase
53: .Op Fl C Ar comment
1.20 markus 54: .Op Fl f Ar output_keyfile
1.2 deraadt 55: .Nm ssh-keygen
56: .Fl p
57: .Op Fl P Ar old_passphrase
58: .Op Fl N Ar new_passphrase
1.9 markus 59: .Op Fl f Ar keyfile
1.2 deraadt 60: .Nm ssh-keygen
1.37 markus 61: .Fl i
1.95 djm 62: .Op Fl m Ar key_format
1.20 markus 63: .Op Fl f Ar input_keyfile
1.16 deraadt 64: .Nm ssh-keygen
1.37 markus 65: .Fl e
1.95 djm 66: .Op Fl m Ar key_format
1.20 markus 67: .Op Fl f Ar input_keyfile
1.16 deraadt 68: .Nm ssh-keygen
1.17 markus 69: .Fl y
1.20 markus 70: .Op Fl f Ar input_keyfile
1.17 markus 71: .Nm ssh-keygen
1.2 deraadt 72: .Fl c
73: .Op Fl P Ar passphrase
74: .Op Fl C Ar comment
1.9 markus 75: .Op Fl f Ar keyfile
76: .Nm ssh-keygen
77: .Fl l
1.35 markus 78: .Op Fl f Ar input_keyfile
79: .Nm ssh-keygen
80: .Fl B
1.20 markus 81: .Op Fl f Ar input_keyfile
1.48 jakob 82: .Nm ssh-keygen
1.82 jmc 83: .Fl D Ar pkcs11
1.48 jakob 84: .Nm ssh-keygen
1.64 djm 85: .Fl F Ar hostname
86: .Op Fl f Ar known_hosts_file
1.79 sthen 87: .Op Fl l
1.64 djm 88: .Nm ssh-keygen
89: .Fl H
90: .Op Fl f Ar known_hosts_file
91: .Nm ssh-keygen
92: .Fl R Ar hostname
93: .Op Fl f Ar known_hosts_file
1.57 jakob 94: .Nm ssh-keygen
95: .Fl r Ar hostname
96: .Op Fl f Ar input_keyfile
97: .Op Fl g
1.60 djm 98: .Nm ssh-keygen
99: .Fl G Ar output_file
1.61 djm 100: .Op Fl v
1.60 djm 101: .Op Fl b Ar bits
102: .Op Fl M Ar memory
103: .Op Fl S Ar start_point
104: .Nm ssh-keygen
105: .Fl T Ar output_file
106: .Fl f Ar input_file
1.61 djm 107: .Op Fl v
1.60 djm 108: .Op Fl a Ar num_trials
109: .Op Fl W Ar generator
1.84 djm 110: .Nm ssh-keygen
111: .Fl s Ar ca_key
112: .Fl I Ar certificate_identity
113: .Op Fl h
114: .Op Fl n Ar principals
1.93 djm 115: .Op Fl O Ar option
1.84 djm 116: .Op Fl V Ar validity_interval
1.93 djm 117: .Op Fl z Ar serial_number
1.84 djm 118: .Ar
1.86 djm 119: .Nm ssh-keygen
120: .Fl L
121: .Op Fl f Ar input_keyfile
1.85 jmc 122: .Ek
1.13 aaron 123: .Sh DESCRIPTION
1.2 deraadt 124: .Nm
1.37 markus 125: generates, manages and converts authentication keys for
1.2 deraadt 126: .Xr ssh 1 .
1.15 deraadt 127: .Nm
1.100 ! naddy 128: can create RSA keys for use by SSH protocol version 1 and DSA, ECDSA or RSA
1.58 jmc 129: keys for use by SSH protocol version 2.
130: The type of key to be generated is specified with the
1.25 markus 131: .Fl t
1.52 djm 132: option.
1.70 djm 133: If invoked without any arguments,
134: .Nm
1.71 jmc 135: will generate an RSA key for use in SSH protocol 2 connections.
1.15 deraadt 136: .Pp
1.60 djm 137: .Nm
138: is also used to generate groups for use in Diffie-Hellman group
139: exchange (DH-GEX).
140: See the
141: .Sx MODULI GENERATION
142: section for details.
143: .Pp
1.2 deraadt 144: Normally each user wishing to use SSH
1.99 djm 145: with public key authentication runs this once to create the authentication
1.1 deraadt 146: key in
1.68 djm 147: .Pa ~/.ssh/identity ,
1.99 djm 148: .Pa ~/.ssh/id_ecdsa ,
1.68 djm 149: .Pa ~/.ssh/id_dsa
1.15 deraadt 150: or
1.68 djm 151: .Pa ~/.ssh/id_rsa .
1.15 deraadt 152: Additionally, the system administrator may use this to generate host keys,
153: as seen in
154: .Pa /etc/rc .
1.2 deraadt 155: .Pp
1.1 deraadt 156: Normally this program generates the key and asks for a file in which
1.12 aaron 157: to store the private key.
158: The public key is stored in a file with the same name but
1.2 deraadt 159: .Dq .pub
1.12 aaron 160: appended.
161: The program also asks for a passphrase.
162: The passphrase may be empty to indicate no passphrase
1.26 markus 163: (host keys must have an empty passphrase), or it may be a string of
1.12 aaron 164: arbitrary length.
1.51 stevesk 165: A passphrase is similar to a password, except it can be a phrase with a
166: series of words, punctuation, numbers, whitespace, or any string of
167: characters you want.
168: Good passphrases are 10-30 characters long, are
1.1 deraadt 169: not simple sentences or otherwise easily guessable (English
1.42 markus 170: prose has only 1-2 bits of entropy per character, and provides very bad
1.51 stevesk 171: passphrases), and contain a mix of upper and lowercase letters,
172: numbers, and non-alphanumeric characters.
1.12 aaron 173: The passphrase can be changed later by using the
1.2 deraadt 174: .Fl p
1.1 deraadt 175: option.
1.2 deraadt 176: .Pp
1.12 aaron 177: There is no way to recover a lost passphrase.
178: If the passphrase is
1.49 deraadt 179: lost or forgotten, a new key must be generated and copied to the
1.1 deraadt 180: corresponding public key to other machines.
1.2 deraadt 181: .Pp
1.37 markus 182: For RSA1 keys,
183: there is also a comment field in the key file that is only for
1.12 aaron 184: convenience to the user to help identify the key.
185: The comment can tell what the key is for, or whatever is useful.
186: The comment is initialized to
1.2 deraadt 187: .Dq user@host
188: when the key is created, but can be changed using the
189: .Fl c
1.1 deraadt 190: option.
1.2 deraadt 191: .Pp
1.15 deraadt 192: After a key is generated, instructions below detail where the keys
193: should be placed to be activated.
194: .Pp
1.2 deraadt 195: The options are as follows:
196: .Bl -tag -width Ds
1.60 djm 197: .It Fl a Ar trials
198: Specifies the number of primality tests to perform when screening DH-GEX
199: candidates using the
200: .Fl T
201: command.
1.66 jmc 202: .It Fl B
203: Show the bubblebabble digest of specified private or public key file.
1.2 deraadt 204: .It Fl b Ar bits
1.12 aaron 205: Specifies the number of bits in the key to create.
1.72 dtucker 206: For RSA keys, the minimum size is 768 bits and the default is 2048 bits.
1.69 djm 207: Generally, 2048 bits is considered sufficient.
1.72 dtucker 208: DSA keys must be exactly 1024 bits as specified by FIPS 186-2.
1.66 jmc 209: .It Fl C Ar comment
210: Provides a new comment.
1.2 deraadt 211: .It Fl c
1.1 deraadt 212: Requests changing the comment in the private and public key files.
1.50 markus 213: This operation is only supported for RSA1 keys.
1.1 deraadt 214: The program will prompt for the file containing the private keys, for
1.41 stevesk 215: the passphrase if the key has one, and for the new comment.
1.81 markus 216: .It Fl D Ar pkcs11
1.83 markus 217: Download the RSA public keys provided by the PKCS#11 shared library
218: .Ar pkcs11 .
1.98 djm 219: When used in combination with
220: .Fl s ,
221: this option indicates that a CA key resides in a PKCS#11 token (see the
222: .Sx CERTIFICATES
223: section for details).
1.37 markus 224: .It Fl e
1.40 markus 225: This option will read a private or public OpenSSH key file and
1.95 djm 226: print to stdout the key in one of the formats specified by the
227: .Fl m
228: option.
229: The default export format is
230: .Dq RFC4716 .
1.96 jmc 231: This option allows exporting OpenSSH keys for use by other programs, including
1.95 djm 232: several commercial SSH implementations.
1.66 jmc 233: .It Fl F Ar hostname
234: Search for the specified
235: .Ar hostname
236: in a
237: .Pa known_hosts
238: file, listing any occurrences found.
239: This option is useful to find hashed host names or addresses and may also be
240: used in conjunction with the
241: .Fl H
242: option to print found keys in a hashed format.
243: .It Fl f Ar filename
244: Specifies the filename of the key file.
245: .It Fl G Ar output_file
246: Generate candidate primes for DH-GEX.
247: These primes must be screened for
248: safety (using the
249: .Fl T
250: option) before use.
1.57 jakob 251: .It Fl g
1.62 jakob 252: Use generic DNS format when printing fingerprint resource records using the
1.63 jmc 253: .Fl r
1.62 jakob 254: command.
1.66 jmc 255: .It Fl H
256: Hash a
257: .Pa known_hosts
1.67 dtucker 258: file.
259: This replaces all hostnames and addresses with hashed representations
260: within the specified file; the original content is moved to a file with
261: a .old suffix.
1.66 jmc 262: These hashes may be used normally by
263: .Nm ssh
264: and
265: .Nm sshd ,
266: but they do not reveal identifying information should the file's contents
267: be disclosed.
268: This option will not modify existing hashed hostnames and is therefore safe
269: to use on files that mix hashed and non-hashed names.
1.84 djm 270: .It Fl h
271: When signing a key, create a host certificate instead of a user
272: certificate.
273: Please see the
274: .Sx CERTIFICATES
275: section for details.
1.85 jmc 276: .It Fl I Ar certificate_identity
1.84 djm 277: Specify the key identity when signing a public key.
278: Please see the
279: .Sx CERTIFICATES
280: section for details.
1.37 markus 281: .It Fl i
282: This option will read an unencrypted private (or public) key file
1.95 djm 283: in the format specified by the
284: .Fl m
285: option and print an OpenSSH compatible private
1.37 markus 286: (or public) key to stdout.
1.95 djm 287: This option allows importing keys from other software, including several
288: commercial SSH implementations.
289: The default import format is
290: .Dq RFC4716 .
1.86 djm 291: .It Fl L
292: Prints the contents of a certificate.
1.9 markus 293: .It Fl l
1.77 grunk 294: Show fingerprint of specified public key file.
1.50 markus 295: Private RSA1 keys are also supported.
296: For RSA and DSA keys
297: .Nm
1.78 jmc 298: tries to find the matching public key file and prints its fingerprint.
299: If combined with
300: .Fl v ,
301: an ASCII art representation of the key is supplied with the fingerprint.
1.96 jmc 302: .It Fl M Ar memory
303: Specify the amount of memory to use (in megabytes) when generating
304: candidate moduli for DH-GEX.
1.95 djm 305: .It Fl m Ar key_format
306: Specify a key format for the
307: .Fl i
308: (import) or
309: .Fl e
1.96 jmc 310: (export) conversion options.
1.95 djm 311: The supported key formats are:
312: .Dq RFC4716
1.96 jmc 313: (RFC 4716/SSH2 public or private key),
1.95 djm 314: .Dq PKCS8
315: (PEM PKCS8 public key)
316: or
317: .Dq PEM
318: (PEM public key).
319: The default conversion format is
320: .Dq RFC4716 .
1.66 jmc 321: .It Fl N Ar new_passphrase
322: Provides the new passphrase.
1.84 djm 323: .It Fl n Ar principals
324: Specify one or more principals (user or host names) to be included in
325: a certificate when signing a key.
326: Multiple principals may be specified, separated by commas.
327: Please see the
328: .Sx CERTIFICATES
329: section for details.
1.93 djm 330: .It Fl O Ar option
331: Specify a certificate option when signing a key.
1.84 djm 332: This option may be specified multiple times.
333: Please see the
334: .Sx CERTIFICATES
335: section for details.
1.93 djm 336: The options that are valid for user certificates are:
1.84 djm 337: .Bl -tag -width Ds
1.89 jmc 338: .It Ic clear
339: Clear all enabled permissions.
340: This is useful for clearing the default set of permissions so permissions may
341: be added individually.
342: .It Ic force-command Ns = Ns Ar command
343: Forces the execution of
344: .Ar command
345: instead of any shell or command specified by the user when
346: the certificate is used for authentication.
1.84 djm 347: .It Ic no-agent-forwarding
348: Disable
349: .Xr ssh-agent 1
1.85 jmc 350: forwarding (permitted by default).
1.84 djm 351: .It Ic no-port-forwarding
1.85 jmc 352: Disable port forwarding (permitted by default).
1.84 djm 353: .It Ic no-pty
1.85 jmc 354: Disable PTY allocation (permitted by default).
1.84 djm 355: .It Ic no-user-rc
356: Disable execution of
357: .Pa ~/.ssh/rc
358: by
1.85 jmc 359: .Xr sshd 8
360: (permitted by default).
1.89 jmc 361: .It Ic no-x11-forwarding
362: Disable X11 forwarding (permitted by default).
1.88 djm 363: .It Ic permit-agent-forwarding
364: Allows
365: .Xr ssh-agent 1
366: forwarding.
1.84 djm 367: .It Ic permit-port-forwarding
368: Allows port forwarding.
369: .It Ic permit-pty
370: Allows PTY allocation.
371: .It Ic permit-user-rc
372: Allows execution of
373: .Pa ~/.ssh/rc
374: by
375: .Xr sshd 8 .
1.89 jmc 376: .It Ic permit-x11-forwarding
377: Allows X11 forwarding.
378: .It Ic source-address Ns = Ns Ar address_list
1.90 jmc 379: Restrict the source addresses from which the certificate is considered valid.
1.84 djm 380: The
381: .Ar address_list
382: is a comma-separated list of one or more address/netmask pairs in CIDR
383: format.
384: .El
385: .Pp
1.93 djm 386: At present, no options are valid for host keys.
1.66 jmc 387: .It Fl P Ar passphrase
388: Provides the (old) passphrase.
1.2 deraadt 389: .It Fl p
1.1 deraadt 390: Requests changing the passphrase of a private key file instead of
1.12 aaron 391: creating a new private key.
392: The program will prompt for the file
1.1 deraadt 393: containing the private key, for the old passphrase, and twice for the
394: new passphrase.
1.5 aaron 395: .It Fl q
396: Silence
397: .Nm ssh-keygen .
398: Used by
399: .Pa /etc/rc
400: when creating a new key.
1.64 djm 401: .It Fl R Ar hostname
402: Removes all keys belonging to
403: .Ar hostname
1.65 jmc 404: from a
1.64 djm 405: .Pa known_hosts
406: file.
1.65 jmc 407: This option is useful to delete hashed hosts (see the
1.64 djm 408: .Fl H
409: option above).
1.66 jmc 410: .It Fl r Ar hostname
411: Print the SSHFP fingerprint resource record named
412: .Ar hostname
413: for the specified public key file.
1.60 djm 414: .It Fl S Ar start
415: Specify start point (in hex) when generating candidate moduli for DH-GEX.
1.84 djm 416: .It Fl s Ar ca_key
417: Certify (sign) a public key using the specified CA key.
418: Please see the
419: .Sx CERTIFICATES
420: section for details.
1.60 djm 421: .It Fl T Ar output_file
422: Test DH group exchange candidate primes (generated using the
423: .Fl G
424: option) for safety.
1.66 jmc 425: .It Fl t Ar type
426: Specifies the type of key to create.
427: The possible values are
428: .Dq rsa1
429: for protocol version 1 and
1.100 ! naddy 430: .Dq dsa ,
! 431: .Dq ecdsa
! 432: or
1.66 jmc 433: .Dq rsa
434: for protocol version 2.
1.84 djm 435: .It Fl V Ar validity_interval
436: Specify a validity interval when signing a certificate.
437: A validity interval may consist of a single time, indicating that the
438: certificate is valid beginning now and expiring at that time, or may consist
439: of two times separated by a colon to indicate an explicit time interval.
440: The start time may be specified as a date in YYYYMMDD format, a time
441: in YYYYMMDDHHMMSS format or a relative time (to the current time) consisting
442: of a minus sign followed by a relative time in the format described in the
443: .Sx TIME FORMATS
444: section of
1.90 jmc 445: .Xr sshd_config 5 .
1.84 djm 446: The end time may be specified as a YYYYMMDD date, a YYYYMMDDHHMMSS time or
447: a relative time starting with a plus character.
448: .Pp
449: For example:
450: .Dq +52w1d
451: (valid from now to 52 weeks and one day from now),
452: .Dq -4w:+4w
453: (valid from four weeks ago to four weeks from now),
454: .Dq 20100101123000:20110101123000
455: (valid from 12:30 PM, January 1st, 2010 to 12:30 PM, January 1st, 2011),
456: .Dq -1d:20110101
457: (valid from yesterday to midnight, January 1st, 2011).
1.61 djm 458: .It Fl v
459: Verbose mode.
460: Causes
461: .Nm
462: to print debugging messages about its progress.
463: This is helpful for debugging moduli generation.
464: Multiple
465: .Fl v
466: options increase the verbosity.
467: The maximum is 3.
1.66 jmc 468: .It Fl W Ar generator
469: Specify desired generator when testing candidate moduli for DH-GEX.
470: .It Fl y
471: This option will read a private
472: OpenSSH format file and print an OpenSSH public key to stdout.
1.93 djm 473: .It Fl z Ar serial_number
474: Specifies a serial number to be embedded in the certificate to distinguish
475: this certificate from others from the same CA.
476: The default serial number is zero.
1.2 deraadt 477: .El
1.60 djm 478: .Sh MODULI GENERATION
479: .Nm
480: may be used to generate groups for the Diffie-Hellman Group Exchange
481: (DH-GEX) protocol.
482: Generating these groups is a two-step process: first, candidate
483: primes are generated using a fast, but memory intensive process.
484: These candidate primes are then tested for suitability (a CPU-intensive
485: process).
486: .Pp
487: Generation of primes is performed using the
488: .Fl G
489: option.
490: The desired length of the primes may be specified by the
491: .Fl b
492: option.
493: For example:
494: .Pp
1.66 jmc 495: .Dl # ssh-keygen -G moduli-2048.candidates -b 2048
1.60 djm 496: .Pp
497: By default, the search for primes begins at a random point in the
498: desired length range.
499: This may be overridden using the
500: .Fl S
501: option, which specifies a different start point (in hex).
502: .Pp
503: Once a set of candidates have been generated, they must be tested for
504: suitability.
505: This may be performed using the
506: .Fl T
507: option.
508: In this mode
509: .Nm
510: will read candidates from standard input (or a file specified using the
511: .Fl f
512: option).
513: For example:
514: .Pp
1.66 jmc 515: .Dl # ssh-keygen -T moduli-2048 -f moduli-2048.candidates
1.60 djm 516: .Pp
517: By default, each candidate will be subjected to 100 primality tests.
518: This may be overridden using the
519: .Fl a
520: option.
521: The DH generator value will be chosen automatically for the
522: prime under consideration.
523: If a specific generator is desired, it may be requested using the
524: .Fl W
525: option.
1.66 jmc 526: Valid generator values are 2, 3, and 5.
1.60 djm 527: .Pp
528: Screened DH groups may be installed in
529: .Pa /etc/moduli .
530: It is important that this file contains moduli of a range of bit lengths and
531: that both ends of a connection share common moduli.
1.84 djm 532: .Sh CERTIFICATES
533: .Nm
534: supports signing of keys to produce certificates that may be used for
535: user or host authentication.
536: Certificates consist of a public key, some identity information, zero or
1.94 jmc 537: more principal (user or host) names and a set of options that
1.84 djm 538: are signed by a Certification Authority (CA) key.
539: Clients or servers may then trust only the CA key and verify its signature
540: on a certificate rather than trusting many user/host keys.
541: Note that OpenSSH certificates are a different, and much simpler, format to
542: the X.509 certificates used in
543: .Xr ssl 8 .
544: .Pp
545: .Nm
546: supports two types of certificates: user and host.
547: User certificates authenticate users to servers, whereas host certificates
1.85 jmc 548: authenticate server hosts to users.
549: To generate a user certificate:
1.84 djm 550: .Pp
551: .Dl $ ssh-keygen -s /path/to/ca_key -I key_id /path/to/user_key.pub
552: .Pp
553: The resultant certificate will be placed in
1.91 djm 554: .Pa /path/to/user_key-cert.pub .
1.84 djm 555: A host certificate requires the
556: .Fl h
557: option:
558: .Pp
559: .Dl $ ssh-keygen -s /path/to/ca_key -I key_id -h /path/to/host_key.pub
560: .Pp
561: The host certificate will be output to
1.91 djm 562: .Pa /path/to/host_key-cert.pub .
1.98 djm 563: .Pp
564: It is possible to sign using a CA key stored in a PKCS#11 token by
565: providing the token library using
566: .Fl D
567: and identifying the CA key by providing its public half as an argument
568: to
569: .Fl s :
570: .Pp
571: .Dl $ ssh-keygen -s ca_key.pub -D libpkcs11.so -I key_id host_key.pub
572: .Pp
573: In all cases,
1.84 djm 574: .Ar key_id
575: is a "key identifier" that is logged by the server when the certificate
576: is used for authentication.
577: .Pp
578: Certificates may be limited to be valid for a set of principal (user/host)
579: names.
580: By default, generated certificates are valid for all users or hosts.
581: To generate a certificate for a specified set of principals:
582: .Pp
583: .Dl $ ssh-keygen -s ca_key -I key_id -n user1,user2 user_key.pub
1.92 jmc 584: .Dl "$ ssh-keygen -s ca_key -I key_id -h -n host.domain user_key.pub"
1.84 djm 585: .Pp
586: Additional limitations on the validity and use of user certificates may
1.94 jmc 587: be specified through certificate options.
1.93 djm 588: A certificate option may disable features of the SSH session, may be
1.84 djm 589: valid only when presented from particular source addresses or may
590: force the use of a specific command.
1.93 djm 591: For a list of valid certificate options, see the documentation for the
1.84 djm 592: .Fl O
593: option above.
594: .Pp
595: Finally, certificates may be defined with a validity lifetime.
596: The
597: .Fl V
598: option allows specification of certificate start and end times.
599: A certificate that is presented at a time outside this range will not be
600: considered valid.
601: By default, certificates have a maximum validity interval.
602: .Pp
603: For certificates to be used for user or host authentication, the CA
604: public key must be trusted by
605: .Xr sshd 8
606: or
607: .Xr ssh 1 .
608: Please refer to those manual pages for details.
1.2 deraadt 609: .Sh FILES
1.100 ! naddy 610: .Bl -tag -width Ds -compact
1.68 djm 611: .It Pa ~/.ssh/identity
1.36 itojun 612: Contains the protocol version 1 RSA authentication identity of the user.
1.12 aaron 613: This file should not be readable by anyone but the user.
614: It is possible to
1.1 deraadt 615: specify a passphrase when generating the key; that passphrase will be
1.100 ! naddy 616: used to encrypt the private part of this file using 3DES.
1.12 aaron 617: This file is not automatically accessed by
1.2 deraadt 618: .Nm
1.1 deraadt 619: but it is offered as the default file for the private key.
1.46 markus 620: .Xr ssh 1
1.15 deraadt 621: will read this file when a login attempt is made.
1.100 ! naddy 622: .Pp
1.68 djm 623: .It Pa ~/.ssh/identity.pub
1.36 itojun 624: Contains the protocol version 1 RSA public key for authentication.
1.12 aaron 625: The contents of this file should be added to
1.68 djm 626: .Pa ~/.ssh/authorized_keys
1.2 deraadt 627: on all machines
1.49 deraadt 628: where the user wishes to log in using RSA authentication.
1.15 deraadt 629: There is no need to keep the contents of this file secret.
1.100 ! naddy 630: .Pp
1.68 djm 631: .It Pa ~/.ssh/id_dsa
1.100 ! naddy 632: .It Pa ~/.ssh/id_ecdsa
! 633: .It Pa ~/.ssh/id_rsa
! 634: Contains the protocol version 2 DSA, ECDSA or RSA authentication identity of the user.
1.15 deraadt 635: This file should not be readable by anyone but the user.
636: It is possible to
637: specify a passphrase when generating the key; that passphrase will be
1.80 dtucker 638: used to encrypt the private part of this file using 128-bit AES.
1.15 deraadt 639: This file is not automatically accessed by
640: .Nm
641: but it is offered as the default file for the private key.
1.46 markus 642: .Xr ssh 1
1.15 deraadt 643: will read this file when a login attempt is made.
1.100 ! naddy 644: .Pp
1.68 djm 645: .It Pa ~/.ssh/id_dsa.pub
1.100 ! naddy 646: .It Pa ~/.ssh/id_ecdsa.pub
1.68 djm 647: .It Pa ~/.ssh/id_rsa.pub
1.100 ! naddy 648: Contains the protocol version 2 DSA, ECDSA or RSA public key for authentication.
1.15 deraadt 649: The contents of this file should be added to
1.68 djm 650: .Pa ~/.ssh/authorized_keys
1.15 deraadt 651: on all machines
1.49 deraadt 652: where the user wishes to log in using public key authentication.
1.12 aaron 653: There is no need to keep the contents of this file secret.
1.100 ! naddy 654: .Pp
1.60 djm 655: .It Pa /etc/moduli
656: Contains Diffie-Hellman groups used for DH-GEX.
657: The file format is described in
658: .Xr moduli 5 .
1.19 aaron 659: .El
1.2 deraadt 660: .Sh SEE ALSO
661: .Xr ssh 1 ,
662: .Xr ssh-add 1 ,
1.8 ericj 663: .Xr ssh-agent 1 ,
1.60 djm 664: .Xr moduli 5 ,
1.30 itojun 665: .Xr sshd 8
1.37 markus 666: .Rs
1.73 markus 667: .%R RFC 4716
668: .%T "The Secure Shell (SSH) Public Key File Format"
669: .%D 2006
1.37 markus 670: .Re
1.59 jmc 671: .Sh AUTHORS
672: OpenSSH is a derivative of the original and free
673: ssh 1.2.12 release by Tatu Ylonen.
674: Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
675: Theo de Raadt and Dug Song
676: removed many bugs, re-added newer features and
677: created OpenSSH.
678: Markus Friedl contributed the support for SSH
679: protocol versions 1.5 and 2.0.
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