Annotation of src/usr.bin/ssh/ssh-keygen.1, Revision 1.196
1.196 ! djm 1: .\" $OpenBSD: ssh-keygen.1,v 1.195 2020/01/23 07:16:38 jmc Exp $
1.1 deraadt 2: .\"
3: .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
4: .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: .\" All rights reserved
6: .\"
1.22 deraadt 7: .\" As far as I am concerned, the code I have written for this software
8: .\" can be used freely for any purpose. Any derived versions of this
9: .\" software must be clearly marked as such, and if the derived work is
10: .\" incompatible with the protocol description in the RFC file, it must be
11: .\" called by a name other than "ssh" or "Secure Shell".
12: .\"
13: .\"
1.33 deraadt 14: .\" Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
15: .\" Copyright (c) 1999 Aaron Campbell. All rights reserved.
16: .\" Copyright (c) 1999 Theo de Raadt. All rights reserved.
1.22 deraadt 17: .\"
18: .\" Redistribution and use in source and binary forms, with or without
19: .\" modification, are permitted provided that the following conditions
20: .\" are met:
21: .\" 1. Redistributions of source code must retain the above copyright
22: .\" notice, this list of conditions and the following disclaimer.
23: .\" 2. Redistributions in binary form must reproduce the above copyright
24: .\" notice, this list of conditions and the following disclaimer in the
25: .\" documentation and/or other materials provided with the distribution.
1.1 deraadt 26: .\"
1.22 deraadt 27: .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
28: .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29: .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30: .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
31: .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
32: .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
33: .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
34: .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
35: .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
36: .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.1 deraadt 37: .\"
1.195 jmc 38: .Dd $Mdocdate: January 23 2020 $
1.2 deraadt 39: .Dt SSH-KEYGEN 1
40: .Os
41: .Sh NAME
42: .Nm ssh-keygen
1.179 jmc 43: .Nd OpenSSH authentication key utility
1.2 deraadt 44: .Sh SYNOPSIS
45: .Nm ssh-keygen
1.25 markus 46: .Op Fl q
1.2 deraadt 47: .Op Fl b Ar bits
48: .Op Fl C Ar comment
1.20 markus 49: .Op Fl f Ar output_keyfile
1.155 djm 50: .Op Fl m Ar format
1.175 djm 51: .Op Fl t Cm dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa
1.171 jmc 52: .Op Fl N Ar new_passphrase
1.191 naddy 53: .Op Fl O Ar option
1.173 naddy 54: .Op Fl w Ar provider
1.2 deraadt 55: .Nm ssh-keygen
56: .Fl p
1.9 markus 57: .Op Fl f Ar keyfile
1.155 djm 58: .Op Fl m Ar format
1.171 jmc 59: .Op Fl N Ar new_passphrase
60: .Op Fl P Ar old_passphrase
1.2 deraadt 61: .Nm ssh-keygen
1.37 markus 62: .Fl i
1.171 jmc 63: .Op Fl f Ar input_keyfile
1.95 djm 64: .Op Fl m Ar key_format
1.16 deraadt 65: .Nm ssh-keygen
1.37 markus 66: .Fl e
1.171 jmc 67: .Op Fl f Ar input_keyfile
1.95 djm 68: .Op Fl m Ar key_format
1.16 deraadt 69: .Nm ssh-keygen
1.17 markus 70: .Fl y
1.20 markus 71: .Op Fl f Ar input_keyfile
1.17 markus 72: .Nm ssh-keygen
1.2 deraadt 73: .Fl c
74: .Op Fl C Ar comment
1.9 markus 75: .Op Fl f Ar keyfile
1.171 jmc 76: .Op Fl P Ar passphrase
1.9 markus 77: .Nm ssh-keygen
78: .Fl l
1.125 naddy 79: .Op Fl v
1.124 djm 80: .Op Fl E Ar fingerprint_hash
1.35 markus 81: .Op Fl f Ar input_keyfile
82: .Nm ssh-keygen
83: .Fl B
1.20 markus 84: .Op Fl f Ar input_keyfile
1.48 jakob 85: .Nm ssh-keygen
1.82 jmc 86: .Fl D Ar pkcs11
1.48 jakob 87: .Nm ssh-keygen
1.64 djm 88: .Fl F Ar hostname
1.170 jmc 89: .Op Fl lv
1.64 djm 90: .Op Fl f Ar known_hosts_file
91: .Nm ssh-keygen
92: .Fl H
93: .Op Fl f Ar known_hosts_file
94: .Nm ssh-keygen
1.187 djm 95: .Fl K
96: .Op Fl w Ar provider
97: .Nm ssh-keygen
1.64 djm 98: .Fl R Ar hostname
99: .Op Fl f Ar known_hosts_file
1.57 jakob 100: .Nm ssh-keygen
101: .Fl r Ar hostname
1.170 jmc 102: .Op Fl g
1.57 jakob 103: .Op Fl f Ar input_keyfile
1.60 djm 104: .Nm ssh-keygen
1.184 djm 105: .Fl M Cm generate
106: .Op Fl O Ar option
1.191 naddy 107: .Ar output_file
1.60 djm 108: .Nm ssh-keygen
1.184 djm 109: .Fl M Cm screen
1.191 naddy 110: .Op Fl f Ar input_file
1.184 djm 111: .Op Fl O Ar option
1.191 naddy 112: .Ar output_file
1.84 djm 113: .Nm ssh-keygen
1.171 jmc 114: .Fl I Ar certificate_identity
1.84 djm 115: .Fl s Ar ca_key
1.170 jmc 116: .Op Fl hU
1.142 djm 117: .Op Fl D Ar pkcs11_provider
1.84 djm 118: .Op Fl n Ar principals
1.93 djm 119: .Op Fl O Ar option
1.84 djm 120: .Op Fl V Ar validity_interval
1.93 djm 121: .Op Fl z Ar serial_number
1.84 djm 122: .Ar
1.86 djm 123: .Nm ssh-keygen
124: .Fl L
125: .Op Fl f Ar input_keyfile
1.102 stevesk 126: .Nm ssh-keygen
127: .Fl A
1.143 djm 128: .Op Fl f Ar prefix_path
1.111 djm 129: .Nm ssh-keygen
130: .Fl k
131: .Fl f Ar krl_file
132: .Op Fl u
1.112 jmc 133: .Op Fl s Ar ca_public
134: .Op Fl z Ar version_number
1.111 djm 135: .Ar
136: .Nm ssh-keygen
137: .Fl Q
138: .Fl f Ar krl_file
139: .Ar
1.163 djm 140: .Nm ssh-keygen
1.196 ! djm 141: .Fl Y Cm find-principals
1.194 djm 142: .Fl s Ar signature_file
143: .Fl f Ar allowed_signers_file
144: .Nm ssh-keygen
1.171 jmc 145: .Fl Y Cm check-novalidate
146: .Fl n Ar namespace
147: .Fl s Ar signature_file
148: .Nm ssh-keygen
1.163 djm 149: .Fl Y Cm sign
150: .Fl f Ar key_file
151: .Fl n Ar namespace
152: .Ar
153: .Nm ssh-keygen
154: .Fl Y Cm verify
1.171 jmc 155: .Fl f Ar allowed_signers_file
1.163 djm 156: .Fl I Ar signer_identity
157: .Fl n Ar namespace
158: .Fl s Ar signature_file
159: .Op Fl r Ar revocation_file
1.13 aaron 160: .Sh DESCRIPTION
1.2 deraadt 161: .Nm
1.37 markus 162: generates, manages and converts authentication keys for
1.2 deraadt 163: .Xr ssh 1 .
1.15 deraadt 164: .Nm
1.140 jmc 165: can create keys for use by SSH protocol version 2.
1.130 jmc 166: .Pp
1.58 jmc 167: The type of key to be generated is specified with the
1.25 markus 168: .Fl t
1.52 djm 169: option.
1.70 djm 170: If invoked without any arguments,
171: .Nm
1.141 naddy 172: will generate an RSA key.
1.15 deraadt 173: .Pp
1.60 djm 174: .Nm
175: is also used to generate groups for use in Diffie-Hellman group
176: exchange (DH-GEX).
177: See the
178: .Sx MODULI GENERATION
179: section for details.
180: .Pp
1.111 djm 181: Finally,
182: .Nm
183: can be used to generate and update Key Revocation Lists, and to test whether
1.112 jmc 184: given keys have been revoked by one.
185: See the
1.111 djm 186: .Sx KEY REVOCATION LISTS
187: section for details.
188: .Pp
1.2 deraadt 189: Normally each user wishing to use SSH
1.99 djm 190: with public key authentication runs this once to create the authentication
1.1 deraadt 191: key in
1.118 naddy 192: .Pa ~/.ssh/id_dsa ,
1.99 djm 193: .Pa ~/.ssh/id_ecdsa ,
1.173 naddy 194: .Pa ~/.ssh/id_ecdsa_sk ,
1.176 naddy 195: .Pa ~/.ssh/id_ed25519 ,
196: .Pa ~/.ssh/id_ed25519_sk
1.15 deraadt 197: or
1.68 djm 198: .Pa ~/.ssh/id_rsa .
1.15 deraadt 199: Additionally, the system administrator may use this to generate host keys,
200: as seen in
201: .Pa /etc/rc .
1.2 deraadt 202: .Pp
1.1 deraadt 203: Normally this program generates the key and asks for a file in which
1.12 aaron 204: to store the private key.
205: The public key is stored in a file with the same name but
1.2 deraadt 206: .Dq .pub
1.12 aaron 207: appended.
208: The program also asks for a passphrase.
209: The passphrase may be empty to indicate no passphrase
1.26 markus 210: (host keys must have an empty passphrase), or it may be a string of
1.12 aaron 211: arbitrary length.
1.51 stevesk 212: A passphrase is similar to a password, except it can be a phrase with a
213: series of words, punctuation, numbers, whitespace, or any string of
214: characters you want.
215: Good passphrases are 10-30 characters long, are
1.1 deraadt 216: not simple sentences or otherwise easily guessable (English
1.42 markus 217: prose has only 1-2 bits of entropy per character, and provides very bad
1.51 stevesk 218: passphrases), and contain a mix of upper and lowercase letters,
219: numbers, and non-alphanumeric characters.
1.12 aaron 220: The passphrase can be changed later by using the
1.2 deraadt 221: .Fl p
1.1 deraadt 222: option.
1.2 deraadt 223: .Pp
1.12 aaron 224: There is no way to recover a lost passphrase.
1.105 djm 225: If the passphrase is lost or forgotten, a new key must be generated
226: and the corresponding public key copied to other machines.
1.2 deraadt 227: .Pp
1.153 djm 228: .Nm
229: will by default write keys in an OpenSSH-specific format.
230: This format is preferred as it offers better protection for
231: keys at rest as well as allowing storage of key comments within
232: the private key file itself.
233: The key comment may be useful to help identify the key.
1.12 aaron 234: The comment is initialized to
1.2 deraadt 235: .Dq user@host
236: when the key is created, but can be changed using the
237: .Fl c
1.1 deraadt 238: option.
1.153 djm 239: .Pp
240: It is still possible for
241: .Nm
242: to write the previously-used PEM format private keys using the
243: .Fl m
244: flag.
245: This may be used when generating new keys, and existing new-format
246: keys may be converted using this option in conjunction with the
247: .Fl p
248: (change passphrase) flag.
1.2 deraadt 249: .Pp
1.15 deraadt 250: After a key is generated, instructions below detail where the keys
251: should be placed to be activated.
252: .Pp
1.2 deraadt 253: The options are as follows:
254: .Bl -tag -width Ds
1.102 stevesk 255: .It Fl A
1.175 djm 256: For each of the key types (rsa, dsa, ecdsa and ed25519)
1.118 naddy 257: for which host keys
1.102 stevesk 258: do not exist, generate the host keys with the default key file path,
259: an empty passphrase, default bits for the key type, and default comment.
1.144 jmc 260: If
1.143 djm 261: .Fl f
1.144 jmc 262: has also been specified, its argument is used as a prefix to the
1.143 djm 263: default path for the resulting host key files.
1.104 jmc 264: This is used by
1.102 stevesk 265: .Pa /etc/rc
266: to generate new host keys.
1.117 djm 267: .It Fl a Ar rounds
1.169 jmc 268: When saving a private key, this option specifies the number of KDF
1.148 djm 269: (key derivation function) rounds used.
1.117 djm 270: Higher numbers result in slower passphrase verification and increased
271: resistance to brute-force password cracking (should the keys be stolen).
1.66 jmc 272: .It Fl B
273: Show the bubblebabble digest of specified private or public key file.
1.2 deraadt 274: .It Fl b Ar bits
1.12 aaron 275: Specifies the number of bits in the key to create.
1.158 dtucker 276: For RSA keys, the minimum size is 1024 bits and the default is 3072 bits.
277: Generally, 3072 bits is considered sufficient.
1.72 dtucker 278: DSA keys must be exactly 1024 bits as specified by FIPS 186-2.
1.106 djm 279: For ECDSA keys, the
280: .Fl b
1.107 deraadt 281: flag determines the key length by selecting from one of three elliptic
1.106 djm 282: curve sizes: 256, 384 or 521 bits.
283: Attempting to use bit lengths other than these three values for ECDSA keys
284: will fail.
1.176 naddy 285: ECDSA-SK, Ed25519 and Ed25519-SK keys have a fixed length and the
1.118 naddy 286: .Fl b
287: flag will be ignored.
1.66 jmc 288: .It Fl C Ar comment
289: Provides a new comment.
1.2 deraadt 290: .It Fl c
1.1 deraadt 291: Requests changing the comment in the private and public key files.
292: The program will prompt for the file containing the private keys, for
1.41 stevesk 293: the passphrase if the key has one, and for the new comment.
1.81 markus 294: .It Fl D Ar pkcs11
1.157 naddy 295: Download the public keys provided by the PKCS#11 shared library
1.83 markus 296: .Ar pkcs11 .
1.98 djm 297: When used in combination with
298: .Fl s ,
299: this option indicates that a CA key resides in a PKCS#11 token (see the
300: .Sx CERTIFICATES
301: section for details).
1.124 djm 302: .It Fl E Ar fingerprint_hash
303: Specifies the hash algorithm used when displaying key fingerprints.
304: Valid options are:
305: .Dq md5
306: and
307: .Dq sha256 .
308: The default is
309: .Dq sha256 .
1.37 markus 310: .It Fl e
1.40 markus 311: This option will read a private or public OpenSSH key file and
1.154 djm 312: print to stdout a public key in one of the formats specified by the
1.95 djm 313: .Fl m
314: option.
315: The default export format is
316: .Dq RFC4716 .
1.96 jmc 317: This option allows exporting OpenSSH keys for use by other programs, including
1.95 djm 318: several commercial SSH implementations.
1.151 djm 319: .It Fl F Ar hostname | [hostname]:port
1.66 jmc 320: Search for the specified
321: .Ar hostname
1.151 djm 322: (with optional port number)
1.66 jmc 323: in a
324: .Pa known_hosts
325: file, listing any occurrences found.
326: This option is useful to find hashed host names or addresses and may also be
327: used in conjunction with the
328: .Fl H
329: option to print found keys in a hashed format.
330: .It Fl f Ar filename
331: Specifies the filename of the key file.
1.57 jakob 332: .It Fl g
1.62 jakob 333: Use generic DNS format when printing fingerprint resource records using the
1.63 jmc 334: .Fl r
1.62 jakob 335: command.
1.66 jmc 336: .It Fl H
337: Hash a
338: .Pa known_hosts
1.67 dtucker 339: file.
340: This replaces all hostnames and addresses with hashed representations
341: within the specified file; the original content is moved to a file with
342: a .old suffix.
1.66 jmc 343: These hashes may be used normally by
344: .Nm ssh
345: and
346: .Nm sshd ,
347: but they do not reveal identifying information should the file's contents
348: be disclosed.
349: This option will not modify existing hashed hostnames and is therefore safe
350: to use on files that mix hashed and non-hashed names.
1.84 djm 351: .It Fl h
352: When signing a key, create a host certificate instead of a user
353: certificate.
354: Please see the
355: .Sx CERTIFICATES
356: section for details.
1.85 jmc 357: .It Fl I Ar certificate_identity
1.84 djm 358: Specify the key identity when signing a public key.
359: Please see the
360: .Sx CERTIFICATES
361: section for details.
1.37 markus 362: .It Fl i
363: This option will read an unencrypted private (or public) key file
1.95 djm 364: in the format specified by the
365: .Fl m
366: option and print an OpenSSH compatible private
1.37 markus 367: (or public) key to stdout.
1.122 jmc 368: This option allows importing keys from other software, including several
369: commercial SSH implementations.
370: The default import format is
371: .Dq RFC4716 .
1.188 jmc 372: .It Fl K
1.187 djm 373: Download resident keys from a FIDO authenticator.
374: Public and private key files will be written to the current directory for
375: each downloaded key.
1.111 djm 376: .It Fl k
377: Generate a KRL file.
378: In this mode,
379: .Nm
380: will generate a KRL file at the location specified via the
381: .Fl f
1.114 jmc 382: flag that revokes every key or certificate presented on the command line.
1.111 djm 383: Keys/certificates to be revoked may be specified by public key file or
384: using the format described in the
385: .Sx KEY REVOCATION LISTS
386: section.
1.86 djm 387: .It Fl L
1.129 djm 388: Prints the contents of one or more certificates.
1.9 markus 389: .It Fl l
1.77 grunk 390: Show fingerprint of specified public key file.
1.50 markus 391: For RSA and DSA keys
392: .Nm
1.78 jmc 393: tries to find the matching public key file and prints its fingerprint.
394: If combined with
395: .Fl v ,
1.132 jmc 396: a visual ASCII art representation of the key is supplied with the
1.131 djm 397: fingerprint.
1.184 djm 398: .It Fl M Cm generate
399: Generate candidate Diffie-Hellman Group Exchange (DH-GEX) parameters for
400: eventual use by the
401: .Sq diffie-hellman-group-exchange-*
402: key exchange methods.
403: The numbers generated by this operation must be further screened before
404: use.
405: See the
406: .Sx MODULI GENERATION
407: section for more information.
408: .It Fl M Cm screen
409: Screen candidate parameters for Diffie-Hellman Group Exchange.
410: This will accept a list of candidate numbers and test that they are
411: safe (Sophie Germain) primes with acceptable group generators.
412: The results of this operation may be added to the
413: .Pa /etc/moduli
414: file.
415: See the
416: .Sx MODULI GENERATION
417: section for more information.
1.95 djm 418: .It Fl m Ar key_format
1.155 djm 419: Specify a key format for key generation, the
1.95 djm 420: .Fl i
1.155 djm 421: (import),
1.95 djm 422: .Fl e
1.155 djm 423: (export) conversion options, and the
424: .Fl p
425: change passphrase operation.
426: The latter may be used to convert between OpenSSH private key and PEM
427: private key formats.
1.95 djm 428: The supported key formats are:
429: .Dq RFC4716
1.96 jmc 430: (RFC 4716/SSH2 public or private key),
1.95 djm 431: .Dq PKCS8
1.161 djm 432: (PKCS8 public or private key)
1.95 djm 433: or
434: .Dq PEM
435: (PEM public key).
1.161 djm 436: By default OpenSSH will write newly-generated private keys in its own
437: format, but when converting public keys for export the default format is
1.95 djm 438: .Dq RFC4716 .
1.148 djm 439: Setting a format of
440: .Dq PEM
441: when generating or updating a supported private key type will cause the
442: key to be stored in the legacy PEM private key format.
1.66 jmc 443: .It Fl N Ar new_passphrase
444: Provides the new passphrase.
1.84 djm 445: .It Fl n Ar principals
446: Specify one or more principals (user or host names) to be included in
447: a certificate when signing a key.
448: Multiple principals may be specified, separated by commas.
449: Please see the
450: .Sx CERTIFICATES
451: section for details.
1.93 djm 452: .It Fl O Ar option
1.184 djm 453: Specify a key/value option.
454: These are specific to the operation that
455: .Nm
456: has been requested to perform.
457: .Pp
458: When signing certificates, one of the options listed in the
1.183 djm 459: .Sx CERTIFICATES
1.184 djm 460: section may be specified here.
461: .Pp
462: When performing moduli generation or screening, one of the options
463: listed in the
464: .Sx MODULI GENERATION
465: section may be specified.
466: .Pp
1.190 jmc 467: When generating a key that will be hosted on a FIDO authenticator,
468: this flag may be used to specify key-specific options.
469: Those supported at present are:
470: .Bl -tag -width Ds
471: .It Cm application
472: Override the default FIDO application/origin string of
1.189 djm 473: .Dq ssh: .
1.190 jmc 474: This may be useful when generating host or domain-specific resident keys.
475: .It Cm device
476: Explicitly specify a
1.189 djm 477: .Xr fido 4
478: device to use, rather than letting the token middleware select one.
1.190 jmc 479: .It Cm no-touch-required
480: Indicate that the generated private key should not require touch
1.185 djm 481: events (user presence) when making signatures.
482: Note that
483: .Xr sshd 8
484: will refuse such signatures by default, unless overridden via
485: an authorized_keys option.
1.190 jmc 486: .It Cm resident
487: Indicate that the key should be stored on the FIDO authenticator itself.
1.185 djm 488: Resident keys may be supported on FIDO2 tokens and typically require that
489: a PIN be set on the token prior to generation.
490: Resident keys may be loaded off the token using
491: .Xr ssh-add 1 .
1.190 jmc 492: .It Cm user
493: A username to be associated with a resident key,
1.189 djm 494: overriding the empty default username.
495: Specifying a username may be useful when generating multiple resident keys
496: for the same application name.
1.190 jmc 497: .El
1.185 djm 498: .Pp
499: The
500: .Fl O
501: option may be specified multiple times.
1.66 jmc 502: .It Fl P Ar passphrase
503: Provides the (old) passphrase.
1.2 deraadt 504: .It Fl p
1.1 deraadt 505: Requests changing the passphrase of a private key file instead of
1.12 aaron 506: creating a new private key.
507: The program will prompt for the file
1.1 deraadt 508: containing the private key, for the old passphrase, and twice for the
509: new passphrase.
1.113 jmc 510: .It Fl Q
511: Test whether keys have been revoked in a KRL.
1.5 aaron 512: .It Fl q
513: Silence
514: .Nm ssh-keygen .
1.152 djm 515: .It Fl R Ar hostname | [hostname]:port
1.151 djm 516: Removes all keys belonging to the specified
1.64 djm 517: .Ar hostname
1.151 djm 518: (with optional port number)
1.65 jmc 519: from a
1.64 djm 520: .Pa known_hosts
521: file.
1.65 jmc 522: This option is useful to delete hashed hosts (see the
1.64 djm 523: .Fl H
524: option above).
1.66 jmc 525: .It Fl r Ar hostname
526: Print the SSHFP fingerprint resource record named
527: .Ar hostname
528: for the specified public key file.
1.84 djm 529: .It Fl s Ar ca_key
530: Certify (sign) a public key using the specified CA key.
531: Please see the
532: .Sx CERTIFICATES
533: section for details.
1.111 djm 534: .Pp
535: When generating a KRL,
536: .Fl s
1.112 jmc 537: specifies a path to a CA public key file used to revoke certificates directly
1.111 djm 538: by key ID or serial number.
539: See the
540: .Sx KEY REVOCATION LISTS
541: section for details.
1.175 djm 542: .It Fl t Cm dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa
1.66 jmc 543: Specifies the type of key to create.
544: The possible values are
1.100 naddy 545: .Dq dsa ,
1.118 naddy 546: .Dq ecdsa ,
1.173 naddy 547: .Dq ecdsa-sk ,
1.118 naddy 548: .Dq ed25519 ,
1.175 djm 549: .Dq ed25519-sk ,
1.100 naddy 550: or
1.139 jmc 551: .Dq rsa .
1.159 djm 552: .Pp
553: This flag may also be used to specify the desired signature type when
1.160 jmc 554: signing certificates using an RSA CA key.
1.159 djm 555: The available RSA signature variants are
556: .Dq ssh-rsa
557: (SHA1 signatures, not recommended),
1.160 jmc 558: .Dq rsa-sha2-256 ,
559: and
1.159 djm 560: .Dq rsa-sha2-512
561: (the default).
1.142 djm 562: .It Fl U
563: When used in combination with
564: .Fl s ,
565: this option indicates that a CA key resides in a
566: .Xr ssh-agent 1 .
567: See the
568: .Sx CERTIFICATES
569: section for more information.
1.112 jmc 570: .It Fl u
571: Update a KRL.
572: When specified with
573: .Fl k ,
1.114 jmc 574: keys listed via the command line are added to the existing KRL rather than
1.112 jmc 575: a new KRL being created.
1.84 djm 576: .It Fl V Ar validity_interval
577: Specify a validity interval when signing a certificate.
578: A validity interval may consist of a single time, indicating that the
579: certificate is valid beginning now and expiring at that time, or may consist
580: of two times separated by a colon to indicate an explicit time interval.
1.145 djm 581: .Pp
582: The start time may be specified as the string
583: .Dq always
584: to indicate the certificate has no specified start time,
1.147 djm 585: a date in YYYYMMDD format, a time in YYYYMMDDHHMM[SS] format,
1.145 djm 586: a relative time (to the current time) consisting of a minus sign followed by
587: an interval in the format described in the
1.116 jmc 588: TIME FORMATS section of
1.90 jmc 589: .Xr sshd_config 5 .
1.145 djm 590: .Pp
1.147 djm 591: The end time may be specified as a YYYYMMDD date, a YYYYMMDDHHMM[SS] time,
1.145 djm 592: a relative time starting with a plus character or the string
593: .Dq forever
594: to indicate that the certificate has no expirty date.
1.84 djm 595: .Pp
596: For example:
597: .Dq +52w1d
598: (valid from now to 52 weeks and one day from now),
599: .Dq -4w:+4w
600: (valid from four weeks ago to four weeks from now),
601: .Dq 20100101123000:20110101123000
602: (valid from 12:30 PM, January 1st, 2010 to 12:30 PM, January 1st, 2011),
603: .Dq -1d:20110101
604: (valid from yesterday to midnight, January 1st, 2011).
1.145 djm 605: .Dq -1m:forever
606: (valid from one minute ago and never expiring).
1.61 djm 607: .It Fl v
608: Verbose mode.
609: Causes
610: .Nm
611: to print debugging messages about its progress.
612: This is helpful for debugging moduli generation.
613: Multiple
614: .Fl v
615: options increase the verbosity.
616: The maximum is 3.
1.173 naddy 617: .It Fl w Ar provider
1.180 naddy 618: Specifies a path to a library that will be used when creating
619: FIDO authenticator-hosted keys, overriding the default of using
620: the internal USB HID support.
1.196 ! djm 621: .It Fl Y Cm find-principals
! 622: Find the principal(s) associated with the public key of a signature,
1.194 djm 623: provided using the
624: .Fl s
625: flag in an authorized signers file provided using the
626: .Fl f
627: flag.
628: The format of the allowed signers file is documented in the
629: .Sx ALLOWED SIGNERS
1.195 jmc 630: section below.
1.196 ! djm 631: If one or more matching principals are found, they are returned on
! 632: standard output.
1.182 jmc 633: .It Fl Y Cm check-novalidate
634: Checks that a signature generated using
635: .Nm
636: .Fl Y Cm sign
637: has a valid structure.
638: This does not validate if a signature comes from an authorized signer.
639: When testing a signature,
640: .Nm
641: accepts a message on standard input and a signature namespace using
642: .Fl n .
643: A file containing the corresponding signature must also be supplied using the
644: .Fl s
645: flag.
646: Successful testing of the signature is signalled by
647: .Nm
648: returning a zero exit status.
1.166 jmc 649: .It Fl Y Cm sign
1.163 djm 650: Cryptographically sign a file or some data using a SSH key.
651: When signing,
652: .Nm
653: accepts zero or more files to sign on the command-line - if no files
654: are specified then
655: .Nm
656: will sign data presented on standard input.
657: Signatures are written to the path of the input file with
658: .Dq .sig
659: appended, or to standard output if the message to be signed was read from
660: standard input.
661: .Pp
662: The key used for signing is specified using the
663: .Fl f
664: option and may refer to either a private key, or a public key with the private
665: half available via
666: .Xr ssh-agent 1 .
667: An additional signature namespace, used to prevent signature confusion across
668: different domains of use (e.g. file signing vs email signing) must be provided
669: via the
670: .Fl n
671: flag.
672: Namespaces are arbitrary strings, and may include:
673: .Dq file
674: for file signing,
675: .Dq email
676: for email signing.
677: For custom uses, it is recommended to use names following a
678: NAMESPACE@YOUR.DOMAIN pattern to generate unambiguous namespaces.
1.166 jmc 679: .It Fl Y Cm verify
1.163 djm 680: Request to verify a signature generated using
681: .Nm
1.166 jmc 682: .Fl Y Cm sign
1.163 djm 683: as described above.
684: When verifying a signature,
685: .Nm
686: accepts a message on standard input and a signature namespace using
687: .Fl n .
688: A file containing the corresponding signature must also be supplied using the
689: .Fl s
690: flag, along with the identity of the signer using
691: .Fl I
692: and a list of allowed signers via the
693: .Fl f
694: flag.
695: The format of the allowed signers file is documented in the
696: .Sx ALLOWED SIGNERS
697: section below.
698: A file containing revoked keys can be passed using the
699: .Fl r
1.165 jmc 700: flag.
701: The revocation file may be a KRL or a one-per-line list of public keys.
1.163 djm 702: Successful verification by an authorized signer is signalled by
703: .Nm
704: returning a zero exit status.
1.181 jmc 705: .It Fl y
706: This option will read a private
707: OpenSSH format file and print an OpenSSH public key to stdout.
1.93 djm 708: .It Fl z Ar serial_number
709: Specifies a serial number to be embedded in the certificate to distinguish
710: this certificate from others from the same CA.
1.156 djm 711: If the
712: .Ar serial_number
713: is prefixed with a
714: .Sq +
715: character, then the serial number will be incremented for each certificate
716: signed on a single command-line.
1.93 djm 717: The default serial number is zero.
1.111 djm 718: .Pp
719: When generating a KRL, the
720: .Fl z
721: flag is used to specify a KRL version number.
1.2 deraadt 722: .El
1.60 djm 723: .Sh MODULI GENERATION
724: .Nm
725: may be used to generate groups for the Diffie-Hellman Group Exchange
726: (DH-GEX) protocol.
727: Generating these groups is a two-step process: first, candidate
728: primes are generated using a fast, but memory intensive process.
729: These candidate primes are then tested for suitability (a CPU-intensive
730: process).
731: .Pp
732: Generation of primes is performed using the
1.184 djm 733: .Fl M Cm generate
1.60 djm 734: option.
735: The desired length of the primes may be specified by the
1.184 djm 736: .Fl O Cm bits
1.60 djm 737: option.
738: For example:
739: .Pp
1.184 djm 740: .Dl # ssh-keygen -M generate -O bits=2048 moduli-2048.candidates
1.60 djm 741: .Pp
742: By default, the search for primes begins at a random point in the
743: desired length range.
744: This may be overridden using the
1.184 djm 745: .Fl O Cm start
1.60 djm 746: option, which specifies a different start point (in hex).
747: .Pp
1.109 dtucker 748: Once a set of candidates have been generated, they must be screened for
1.60 djm 749: suitability.
750: This may be performed using the
1.184 djm 751: .Fl M Cm screen
1.60 djm 752: option.
753: In this mode
754: .Nm
755: will read candidates from standard input (or a file specified using the
756: .Fl f
757: option).
758: For example:
759: .Pp
1.184 djm 760: .Dl # ssh-keygen -M screen -f moduli-2048.candidates moduli-2048
1.60 djm 761: .Pp
762: By default, each candidate will be subjected to 100 primality tests.
763: This may be overridden using the
1.184 djm 764: .Fl O Cm prime-tests
1.60 djm 765: option.
766: The DH generator value will be chosen automatically for the
767: prime under consideration.
768: If a specific generator is desired, it may be requested using the
1.184 djm 769: .Fl O Cm generator
1.60 djm 770: option.
1.66 jmc 771: Valid generator values are 2, 3, and 5.
1.60 djm 772: .Pp
773: Screened DH groups may be installed in
774: .Pa /etc/moduli .
775: It is important that this file contains moduli of a range of bit lengths and
776: that both ends of a connection share common moduli.
1.184 djm 777: .Pp
778: A number of options are available for moduli generation and screening via the
779: .Fl O
780: flag:
1.186 jmc 781: .Bl -tag -width Ds
1.184 djm 782: .It Ic lines Ns = Ns Ar number
783: Exit after screening the specified number of lines while performing DH
784: candidate screening.
785: .It Ic start-line Ns = Ns Ar line-number
786: Start screening at the specified line number while performing DH candidate
787: screening.
788: .It Ic checkpoint Ns = Ns Ar filename
789: Write the last line processed to the specified file while performing DH
790: candidate screening.
791: This will be used to skip lines in the input file that have already been
792: processed if the job is restarted.
793: .It Ic memory Ns = Ns Ar mbytes
794: Specify the amount of memory to use (in megabytes) when generating
795: candidate moduli for DH-GEX.
796: .It Ic start Ns = Ns Ar hex-value
797: Specify start point (in hex) when generating candidate moduli for DH-GEX.
798: .It Ic generator Ns = Ns Ar value
799: Specify desired generator (in decimal) when testing candidate moduli for DH-GEX.
800: .El
1.84 djm 801: .Sh CERTIFICATES
802: .Nm
803: supports signing of keys to produce certificates that may be used for
804: user or host authentication.
805: Certificates consist of a public key, some identity information, zero or
1.94 jmc 806: more principal (user or host) names and a set of options that
1.84 djm 807: are signed by a Certification Authority (CA) key.
808: Clients or servers may then trust only the CA key and verify its signature
809: on a certificate rather than trusting many user/host keys.
810: Note that OpenSSH certificates are a different, and much simpler, format to
811: the X.509 certificates used in
812: .Xr ssl 8 .
813: .Pp
814: .Nm
815: supports two types of certificates: user and host.
816: User certificates authenticate users to servers, whereas host certificates
1.85 jmc 817: authenticate server hosts to users.
818: To generate a user certificate:
1.84 djm 819: .Pp
820: .Dl $ ssh-keygen -s /path/to/ca_key -I key_id /path/to/user_key.pub
821: .Pp
822: The resultant certificate will be placed in
1.91 djm 823: .Pa /path/to/user_key-cert.pub .
1.84 djm 824: A host certificate requires the
825: .Fl h
826: option:
827: .Pp
828: .Dl $ ssh-keygen -s /path/to/ca_key -I key_id -h /path/to/host_key.pub
829: .Pp
830: The host certificate will be output to
1.91 djm 831: .Pa /path/to/host_key-cert.pub .
1.98 djm 832: .Pp
833: It is possible to sign using a CA key stored in a PKCS#11 token by
834: providing the token library using
835: .Fl D
836: and identifying the CA key by providing its public half as an argument
837: to
838: .Fl s :
839: .Pp
1.127 naddy 840: .Dl $ ssh-keygen -s ca_key.pub -D libpkcs11.so -I key_id user_key.pub
1.142 djm 841: .Pp
842: Similarly, it is possible for the CA key to be hosted in a
843: .Xr ssh-agent 1 .
844: This is indicated by the
845: .Fl U
846: flag and, again, the CA key must be identified by its public half.
847: .Pp
848: .Dl $ ssh-keygen -Us ca_key.pub -I key_id user_key.pub
1.98 djm 849: .Pp
850: In all cases,
1.84 djm 851: .Ar key_id
852: is a "key identifier" that is logged by the server when the certificate
853: is used for authentication.
854: .Pp
855: Certificates may be limited to be valid for a set of principal (user/host)
856: names.
857: By default, generated certificates are valid for all users or hosts.
858: To generate a certificate for a specified set of principals:
859: .Pp
860: .Dl $ ssh-keygen -s ca_key -I key_id -n user1,user2 user_key.pub
1.127 naddy 861: .Dl "$ ssh-keygen -s ca_key -I key_id -h -n host.domain host_key.pub"
1.84 djm 862: .Pp
863: Additional limitations on the validity and use of user certificates may
1.94 jmc 864: be specified through certificate options.
1.93 djm 865: A certificate option may disable features of the SSH session, may be
1.84 djm 866: valid only when presented from particular source addresses or may
867: force the use of a specific command.
1.183 djm 868: .Pp
869: The options that are valid for user certificates are:
870: .Pp
871: .Bl -tag -width Ds -compact
872: .It Ic clear
873: Clear all enabled permissions.
874: This is useful for clearing the default set of permissions so permissions may
875: be added individually.
876: .Pp
877: .It Ic critical : Ns Ar name Ns Op Ns = Ns Ar contents
878: .It Ic extension : Ns Ar name Ns Op Ns = Ns Ar contents
879: Includes an arbitrary certificate critical option or extension.
880: The specified
881: .Ar name
882: should include a domain suffix, e.g.\&
883: .Dq name@example.com .
884: If
885: .Ar contents
886: is specified then it is included as the contents of the extension/option
887: encoded as a string, otherwise the extension/option is created with no
888: contents (usually indicating a flag).
889: Extensions may be ignored by a client or server that does not recognise them,
890: whereas unknown critical options will cause the certificate to be refused.
891: .Pp
892: .It Ic force-command Ns = Ns Ar command
893: Forces the execution of
894: .Ar command
895: instead of any shell or command specified by the user when
896: the certificate is used for authentication.
897: .Pp
898: .It Ic no-agent-forwarding
899: Disable
900: .Xr ssh-agent 1
901: forwarding (permitted by default).
902: .Pp
903: .It Ic no-port-forwarding
904: Disable port forwarding (permitted by default).
905: .Pp
906: .It Ic no-pty
907: Disable PTY allocation (permitted by default).
908: .Pp
909: .It Ic no-user-rc
910: Disable execution of
911: .Pa ~/.ssh/rc
912: by
913: .Xr sshd 8
914: (permitted by default).
915: .Pp
916: .It Ic no-x11-forwarding
917: Disable X11 forwarding (permitted by default).
918: .Pp
919: .It Ic permit-agent-forwarding
920: Allows
921: .Xr ssh-agent 1
922: forwarding.
923: .Pp
924: .It Ic permit-port-forwarding
925: Allows port forwarding.
926: .Pp
927: .It Ic permit-pty
928: Allows PTY allocation.
929: .Pp
930: .It Ic permit-user-rc
931: Allows execution of
932: .Pa ~/.ssh/rc
933: by
934: .Xr sshd 8 .
935: .Pp
936: .It Ic permit-X11-forwarding
937: Allows X11 forwarding.
938: .Pp
939: .It Ic no-touch-required
940: Do not require signatures made using this key require demonstration
1.193 naddy 941: of user presence (e.g. by having the user touch the authenticator).
1.192 naddy 942: This option only makes sense for the FIDO authenticator algorithms
1.183 djm 943: .Cm ecdsa-sk
944: and
945: .Cm ed25519-sk .
946: .Pp
947: .It Ic source-address Ns = Ns Ar address_list
948: Restrict the source addresses from which the certificate is considered valid.
949: The
950: .Ar address_list
951: is a comma-separated list of one or more address/netmask pairs in CIDR
952: format.
953: .El
954: .Pp
955: At present, no standard options are valid for host keys.
1.84 djm 956: .Pp
957: Finally, certificates may be defined with a validity lifetime.
958: The
959: .Fl V
960: option allows specification of certificate start and end times.
961: A certificate that is presented at a time outside this range will not be
962: considered valid.
1.110 jmc 963: By default, certificates are valid from
964: .Ux
965: Epoch to the distant future.
1.84 djm 966: .Pp
967: For certificates to be used for user or host authentication, the CA
968: public key must be trusted by
969: .Xr sshd 8
970: or
971: .Xr ssh 1 .
972: Please refer to those manual pages for details.
1.111 djm 973: .Sh KEY REVOCATION LISTS
974: .Nm
975: is able to manage OpenSSH format Key Revocation Lists (KRLs).
976: These binary files specify keys or certificates to be revoked using a
1.119 tedu 977: compact format, taking as little as one bit per certificate if they are being
1.111 djm 978: revoked by serial number.
979: .Pp
980: KRLs may be generated using the
981: .Fl k
982: flag.
1.114 jmc 983: This option reads one or more files from the command line and generates a new
1.111 djm 984: KRL.
985: The files may either contain a KRL specification (see below) or public keys,
986: listed one per line.
987: Plain public keys are revoked by listing their hash or contents in the KRL and
988: certificates revoked by serial number or key ID (if the serial is zero or
989: not available).
990: .Pp
991: Revoking keys using a KRL specification offers explicit control over the
992: types of record used to revoke keys and may be used to directly revoke
993: certificates by serial number or key ID without having the complete original
994: certificate on hand.
995: A KRL specification consists of lines containing one of the following directives
996: followed by a colon and some directive-specific information.
997: .Bl -tag -width Ds
1.115 jmc 998: .It Cm serial : Ar serial_number Ns Op - Ns Ar serial_number
1.111 djm 999: Revokes a certificate with the specified serial number.
1.112 jmc 1000: Serial numbers are 64-bit values, not including zero and may be expressed
1.111 djm 1001: in decimal, hex or octal.
1002: If two serial numbers are specified separated by a hyphen, then the range
1003: of serial numbers including and between each is revoked.
1004: The CA key must have been specified on the
1005: .Nm
1.114 jmc 1006: command line using the
1.111 djm 1007: .Fl s
1008: option.
1009: .It Cm id : Ar key_id
1010: Revokes a certificate with the specified key ID string.
1011: The CA key must have been specified on the
1012: .Nm
1.114 jmc 1013: command line using the
1.111 djm 1014: .Fl s
1015: option.
1016: .It Cm key : Ar public_key
1017: Revokes the specified key.
1.112 jmc 1018: If a certificate is listed, then it is revoked as a plain public key.
1.111 djm 1019: .It Cm sha1 : Ar public_key
1.149 djm 1020: Revokes the specified key by including its SHA1 hash in the KRL.
1021: .It Cm sha256 : Ar public_key
1022: Revokes the specified key by including its SHA256 hash in the KRL.
1023: KRLs that revoke keys by SHA256 hash are not supported by OpenSSH versions
1024: prior to 7.9.
1025: .It Cm hash : Ar fingerprint
1.150 djm 1026: Revokes a key using a fingerprint hash, as obtained from a
1.149 djm 1027: .Xr sshd 8
1028: authentication log message or the
1029: .Nm
1030: .Fl l
1031: flag.
1032: Only SHA256 fingerprints are supported here and resultant KRLs are
1033: not supported by OpenSSH versions prior to 7.9.
1.111 djm 1034: .El
1035: .Pp
1036: KRLs may be updated using the
1037: .Fl u
1038: flag in addition to
1039: .Fl k .
1.114 jmc 1040: When this option is specified, keys listed via the command line are merged into
1.111 djm 1041: the KRL, adding to those already there.
1042: .Pp
1043: It is also possible, given a KRL, to test whether it revokes a particular key
1044: (or keys).
1045: The
1046: .Fl Q
1.128 jmc 1047: flag will query an existing KRL, testing each key specified on the command line.
1.114 jmc 1048: If any key listed on the command line has been revoked (or an error encountered)
1.111 djm 1049: then
1050: .Nm
1051: will exit with a non-zero exit status.
1052: A zero exit status will only be returned if no key was revoked.
1.163 djm 1053: .Sh ALLOWED SIGNERS
1054: When verifying signatures,
1055: .Nm
1056: uses a simple list of identities and keys to determine whether a signature
1057: comes from an authorized source.
1058: This "allowed signers" file uses a format patterned after the
1059: AUTHORIZED_KEYS FILE FORMAT described in
1.165 jmc 1060: .Xr sshd 8 .
1.163 djm 1061: Each line of the file contains the following space-separated fields:
1062: principals, options, keytype, base64-encoded key.
1063: Empty lines and lines starting with a
1064: .Ql #
1065: are ignored as comments.
1066: .Pp
1067: The principals field is a pattern-list (See PATTERNS in
1068: .Xr ssh_config 5 )
1069: consisting of one or more comma-separated USER@DOMAIN identity patterns
1070: that are accepted for signing.
1071: When verifying, the identity presented via the
1.172 jmc 1072: .Fl I
1073: option must match a principals pattern in order for the corresponding key to be
1.163 djm 1074: considered acceptable for verification.
1075: .Pp
1076: The options (if present) consist of comma-separated option specifications.
1077: No spaces are permitted, except within double quotes.
1078: The following option specifications are supported (note that option keywords
1079: are case-insensitive):
1080: .Bl -tag -width Ds
1081: .It Cm cert-authority
1082: Indicates that this key is accepted as a certificate authority (CA) and
1083: that certificates signed by this CA may be accepted for verification.
1084: .It Cm namespaces="namespace-list"
1085: Specifies a pattern-list of namespaces that are accepted for this key.
1.164 djm 1086: If this option is present, the signature namespace embedded in the
1.163 djm 1087: signature object and presented on the verification command-line must
1088: match the specified list before the key will be considered acceptable.
1089: .El
1090: .Pp
1091: When verifying signatures made by certificates, the expected principal
1092: name must match both the principals pattern in the allowed signers file and
1093: the principals embedded in the certificate itself.
1094: .Pp
1095: An example allowed signers file:
1096: .Bd -literal -offset 3n
1097: # Comments allowed at start of line
1098: user1@example.com,user2@example.com ssh-rsa AAAAX1...
1099: # A certificate authority, trusted for all principals in a domain.
1100: *@example.com cert-authority ssh-ed25519 AAAB4...
1101: # A key that is accepted only for file signing.
1102: user2@example.com namespaces="file" ssh-ed25519 AAA41...
1103: .Ed
1.173 naddy 1104: .Sh ENVIRONMENT
1105: .Bl -tag -width Ds
1106: .It Ev SSH_SK_PROVIDER
1.180 naddy 1107: Specifies the path to a library used to interact with FIDO authenticators.
1.173 naddy 1108: .El
1.2 deraadt 1109: .Sh FILES
1.100 naddy 1110: .Bl -tag -width Ds -compact
1.68 djm 1111: .It Pa ~/.ssh/id_dsa
1.100 naddy 1112: .It Pa ~/.ssh/id_ecdsa
1.173 naddy 1113: .It Pa ~/.ssh/id_ecdsa_sk
1.118 naddy 1114: .It Pa ~/.ssh/id_ed25519
1.176 naddy 1115: .It Pa ~/.ssh/id_ed25519_sk
1.100 naddy 1116: .It Pa ~/.ssh/id_rsa
1.180 naddy 1117: Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
1118: authenticator-hosted Ed25519 or RSA authentication identity of the user.
1.15 deraadt 1119: This file should not be readable by anyone but the user.
1120: It is possible to
1121: specify a passphrase when generating the key; that passphrase will be
1.80 dtucker 1122: used to encrypt the private part of this file using 128-bit AES.
1.15 deraadt 1123: This file is not automatically accessed by
1124: .Nm
1125: but it is offered as the default file for the private key.
1.46 markus 1126: .Xr ssh 1
1.15 deraadt 1127: will read this file when a login attempt is made.
1.100 naddy 1128: .Pp
1.68 djm 1129: .It Pa ~/.ssh/id_dsa.pub
1.100 naddy 1130: .It Pa ~/.ssh/id_ecdsa.pub
1.173 naddy 1131: .It Pa ~/.ssh/id_ecdsa_sk.pub
1.118 naddy 1132: .It Pa ~/.ssh/id_ed25519.pub
1.176 naddy 1133: .It Pa ~/.ssh/id_ed25519_sk.pub
1.68 djm 1134: .It Pa ~/.ssh/id_rsa.pub
1.180 naddy 1135: Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
1136: authenticator-hosted Ed25519 or RSA public key for authentication.
1.15 deraadt 1137: The contents of this file should be added to
1.68 djm 1138: .Pa ~/.ssh/authorized_keys
1.15 deraadt 1139: on all machines
1.49 deraadt 1140: where the user wishes to log in using public key authentication.
1.12 aaron 1141: There is no need to keep the contents of this file secret.
1.100 naddy 1142: .Pp
1.60 djm 1143: .It Pa /etc/moduli
1144: Contains Diffie-Hellman groups used for DH-GEX.
1145: The file format is described in
1146: .Xr moduli 5 .
1.19 aaron 1147: .El
1.2 deraadt 1148: .Sh SEE ALSO
1149: .Xr ssh 1 ,
1150: .Xr ssh-add 1 ,
1.8 ericj 1151: .Xr ssh-agent 1 ,
1.60 djm 1152: .Xr moduli 5 ,
1.30 itojun 1153: .Xr sshd 8
1.37 markus 1154: .Rs
1.73 markus 1155: .%R RFC 4716
1156: .%T "The Secure Shell (SSH) Public Key File Format"
1157: .%D 2006
1.37 markus 1158: .Re
1.59 jmc 1159: .Sh AUTHORS
1160: OpenSSH is a derivative of the original and free
1161: ssh 1.2.12 release by Tatu Ylonen.
1162: Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
1163: Theo de Raadt and Dug Song
1164: removed many bugs, re-added newer features and
1165: created OpenSSH.
1166: Markus Friedl contributed the support for SSH
1167: protocol versions 1.5 and 2.0.
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