Annotation of src/usr.bin/ssh/ssh-keygen.1, Revision 1.203
1.203 ! djm 1: .\" $OpenBSD: ssh-keygen.1,v 1.202 2020/02/24 04:27:58 dtucker 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: .\"
1.203 ! djm 38: .Dd $Mdocdate: February 24 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
1.203 ! djm 138: .Op Fl l
1.111 djm 139: .Fl f Ar krl_file
140: .Ar
1.163 djm 141: .Nm ssh-keygen
1.196 djm 142: .Fl Y Cm find-principals
1.194 djm 143: .Fl s Ar signature_file
144: .Fl f Ar allowed_signers_file
145: .Nm ssh-keygen
1.171 jmc 146: .Fl Y Cm check-novalidate
147: .Fl n Ar namespace
148: .Fl s Ar signature_file
149: .Nm ssh-keygen
1.163 djm 150: .Fl Y Cm sign
151: .Fl f Ar key_file
152: .Fl n Ar namespace
153: .Ar
154: .Nm ssh-keygen
155: .Fl Y Cm verify
1.171 jmc 156: .Fl f Ar allowed_signers_file
1.163 djm 157: .Fl I Ar signer_identity
158: .Fl n Ar namespace
159: .Fl s Ar signature_file
160: .Op Fl r Ar revocation_file
1.13 aaron 161: .Sh DESCRIPTION
1.2 deraadt 162: .Nm
1.37 markus 163: generates, manages and converts authentication keys for
1.2 deraadt 164: .Xr ssh 1 .
1.15 deraadt 165: .Nm
1.140 jmc 166: can create keys for use by SSH protocol version 2.
1.130 jmc 167: .Pp
1.58 jmc 168: The type of key to be generated is specified with the
1.25 markus 169: .Fl t
1.52 djm 170: option.
1.70 djm 171: If invoked without any arguments,
172: .Nm
1.141 naddy 173: will generate an RSA key.
1.15 deraadt 174: .Pp
1.60 djm 175: .Nm
176: is also used to generate groups for use in Diffie-Hellman group
177: exchange (DH-GEX).
178: See the
179: .Sx MODULI GENERATION
180: section for details.
181: .Pp
1.111 djm 182: Finally,
183: .Nm
184: can be used to generate and update Key Revocation Lists, and to test whether
1.112 jmc 185: given keys have been revoked by one.
186: See the
1.111 djm 187: .Sx KEY REVOCATION LISTS
188: section for details.
189: .Pp
1.2 deraadt 190: Normally each user wishing to use SSH
1.99 djm 191: with public key authentication runs this once to create the authentication
1.1 deraadt 192: key in
1.118 naddy 193: .Pa ~/.ssh/id_dsa ,
1.99 djm 194: .Pa ~/.ssh/id_ecdsa ,
1.173 naddy 195: .Pa ~/.ssh/id_ecdsa_sk ,
1.176 naddy 196: .Pa ~/.ssh/id_ed25519 ,
197: .Pa ~/.ssh/id_ed25519_sk
1.15 deraadt 198: or
1.68 djm 199: .Pa ~/.ssh/id_rsa .
1.15 deraadt 200: Additionally, the system administrator may use this to generate host keys,
201: as seen in
202: .Pa /etc/rc .
1.2 deraadt 203: .Pp
1.1 deraadt 204: Normally this program generates the key and asks for a file in which
1.12 aaron 205: to store the private key.
206: The public key is stored in a file with the same name but
1.2 deraadt 207: .Dq .pub
1.12 aaron 208: appended.
209: The program also asks for a passphrase.
210: The passphrase may be empty to indicate no passphrase
1.26 markus 211: (host keys must have an empty passphrase), or it may be a string of
1.12 aaron 212: arbitrary length.
1.51 stevesk 213: A passphrase is similar to a password, except it can be a phrase with a
214: series of words, punctuation, numbers, whitespace, or any string of
215: characters you want.
216: Good passphrases are 10-30 characters long, are
1.1 deraadt 217: not simple sentences or otherwise easily guessable (English
1.42 markus 218: prose has only 1-2 bits of entropy per character, and provides very bad
1.51 stevesk 219: passphrases), and contain a mix of upper and lowercase letters,
220: numbers, and non-alphanumeric characters.
1.12 aaron 221: The passphrase can be changed later by using the
1.2 deraadt 222: .Fl p
1.1 deraadt 223: option.
1.2 deraadt 224: .Pp
1.12 aaron 225: There is no way to recover a lost passphrase.
1.105 djm 226: If the passphrase is lost or forgotten, a new key must be generated
227: and the corresponding public key copied to other machines.
1.2 deraadt 228: .Pp
1.153 djm 229: .Nm
230: will by default write keys in an OpenSSH-specific format.
231: This format is preferred as it offers better protection for
232: keys at rest as well as allowing storage of key comments within
233: the private key file itself.
234: The key comment may be useful to help identify the key.
1.12 aaron 235: The comment is initialized to
1.2 deraadt 236: .Dq user@host
237: when the key is created, but can be changed using the
238: .Fl c
1.1 deraadt 239: option.
1.153 djm 240: .Pp
241: It is still possible for
242: .Nm
243: to write the previously-used PEM format private keys using the
244: .Fl m
245: flag.
246: This may be used when generating new keys, and existing new-format
247: keys may be converted using this option in conjunction with the
248: .Fl p
249: (change passphrase) flag.
1.2 deraadt 250: .Pp
1.15 deraadt 251: After a key is generated, instructions below detail where the keys
252: should be placed to be activated.
253: .Pp
1.2 deraadt 254: The options are as follows:
255: .Bl -tag -width Ds
1.102 stevesk 256: .It Fl A
1.175 djm 257: For each of the key types (rsa, dsa, ecdsa and ed25519)
1.118 naddy 258: for which host keys
1.102 stevesk 259: do not exist, generate the host keys with the default key file path,
260: an empty passphrase, default bits for the key type, and default comment.
1.144 jmc 261: If
1.143 djm 262: .Fl f
1.144 jmc 263: has also been specified, its argument is used as a prefix to the
1.143 djm 264: default path for the resulting host key files.
1.104 jmc 265: This is used by
1.102 stevesk 266: .Pa /etc/rc
267: to generate new host keys.
1.117 djm 268: .It Fl a Ar rounds
1.169 jmc 269: When saving a private key, this option specifies the number of KDF
1.148 djm 270: (key derivation function) rounds used.
1.117 djm 271: Higher numbers result in slower passphrase verification and increased
272: resistance to brute-force password cracking (should the keys be stolen).
1.66 jmc 273: .It Fl B
274: Show the bubblebabble digest of specified private or public key file.
1.2 deraadt 275: .It Fl b Ar bits
1.12 aaron 276: Specifies the number of bits in the key to create.
1.158 dtucker 277: For RSA keys, the minimum size is 1024 bits and the default is 3072 bits.
278: Generally, 3072 bits is considered sufficient.
1.72 dtucker 279: DSA keys must be exactly 1024 bits as specified by FIPS 186-2.
1.106 djm 280: For ECDSA keys, the
281: .Fl b
1.107 deraadt 282: flag determines the key length by selecting from one of three elliptic
1.106 djm 283: curve sizes: 256, 384 or 521 bits.
284: Attempting to use bit lengths other than these three values for ECDSA keys
285: will fail.
1.176 naddy 286: ECDSA-SK, Ed25519 and Ed25519-SK keys have a fixed length and the
1.118 naddy 287: .Fl b
288: flag will be ignored.
1.66 jmc 289: .It Fl C Ar comment
290: Provides a new comment.
1.2 deraadt 291: .It Fl c
1.1 deraadt 292: Requests changing the comment in the private and public key files.
293: The program will prompt for the file containing the private keys, for
1.41 stevesk 294: the passphrase if the key has one, and for the new comment.
1.81 markus 295: .It Fl D Ar pkcs11
1.157 naddy 296: Download the public keys provided by the PKCS#11 shared library
1.83 markus 297: .Ar pkcs11 .
1.98 djm 298: When used in combination with
299: .Fl s ,
300: this option indicates that a CA key resides in a PKCS#11 token (see the
301: .Sx CERTIFICATES
302: section for details).
1.124 djm 303: .It Fl E Ar fingerprint_hash
304: Specifies the hash algorithm used when displaying key fingerprints.
305: Valid options are:
306: .Dq md5
307: and
308: .Dq sha256 .
309: The default is
310: .Dq sha256 .
1.37 markus 311: .It Fl e
1.40 markus 312: This option will read a private or public OpenSSH key file and
1.154 djm 313: print to stdout a public key in one of the formats specified by the
1.95 djm 314: .Fl m
315: option.
316: The default export format is
317: .Dq RFC4716 .
1.96 jmc 318: This option allows exporting OpenSSH keys for use by other programs, including
1.95 djm 319: several commercial SSH implementations.
1.151 djm 320: .It Fl F Ar hostname | [hostname]:port
1.66 jmc 321: Search for the specified
322: .Ar hostname
1.151 djm 323: (with optional port number)
1.66 jmc 324: in a
325: .Pa known_hosts
326: file, listing any occurrences found.
327: This option is useful to find hashed host names or addresses and may also be
328: used in conjunction with the
329: .Fl H
330: option to print found keys in a hashed format.
331: .It Fl f Ar filename
332: Specifies the filename of the key file.
1.57 jakob 333: .It Fl g
1.62 jakob 334: Use generic DNS format when printing fingerprint resource records using the
1.63 jmc 335: .Fl r
1.62 jakob 336: command.
1.66 jmc 337: .It Fl H
338: Hash a
339: .Pa known_hosts
1.67 dtucker 340: file.
341: This replaces all hostnames and addresses with hashed representations
342: within the specified file; the original content is moved to a file with
343: a .old suffix.
1.66 jmc 344: These hashes may be used normally by
345: .Nm ssh
346: and
347: .Nm sshd ,
348: but they do not reveal identifying information should the file's contents
349: be disclosed.
350: This option will not modify existing hashed hostnames and is therefore safe
351: to use on files that mix hashed and non-hashed names.
1.84 djm 352: .It Fl h
353: When signing a key, create a host certificate instead of a user
354: certificate.
355: Please see the
356: .Sx CERTIFICATES
357: section for details.
1.85 jmc 358: .It Fl I Ar certificate_identity
1.84 djm 359: Specify the key identity when signing a public key.
360: Please see the
361: .Sx CERTIFICATES
362: section for details.
1.37 markus 363: .It Fl i
364: This option will read an unencrypted private (or public) key file
1.95 djm 365: in the format specified by the
366: .Fl m
367: option and print an OpenSSH compatible private
1.37 markus 368: (or public) key to stdout.
1.122 jmc 369: This option allows importing keys from other software, including several
370: commercial SSH implementations.
371: The default import format is
372: .Dq RFC4716 .
1.188 jmc 373: .It Fl K
1.187 djm 374: Download resident keys from a FIDO authenticator.
375: Public and private key files will be written to the current directory for
376: each downloaded key.
1.111 djm 377: .It Fl k
378: Generate a KRL file.
379: In this mode,
380: .Nm
381: will generate a KRL file at the location specified via the
382: .Fl f
1.114 jmc 383: flag that revokes every key or certificate presented on the command line.
1.111 djm 384: Keys/certificates to be revoked may be specified by public key file or
385: using the format described in the
386: .Sx KEY REVOCATION LISTS
387: section.
1.86 djm 388: .It Fl L
1.129 djm 389: Prints the contents of one or more certificates.
1.9 markus 390: .It Fl l
1.77 grunk 391: Show fingerprint of specified public key file.
1.50 markus 392: For RSA and DSA keys
393: .Nm
1.78 jmc 394: tries to find the matching public key file and prints its fingerprint.
395: If combined with
396: .Fl v ,
1.132 jmc 397: a visual ASCII art representation of the key is supplied with the
1.131 djm 398: fingerprint.
1.184 djm 399: .It Fl M Cm generate
400: Generate candidate Diffie-Hellman Group Exchange (DH-GEX) parameters for
401: eventual use by the
402: .Sq diffie-hellman-group-exchange-*
403: key exchange methods.
404: The numbers generated by this operation must be further screened before
405: use.
406: See the
407: .Sx MODULI GENERATION
408: section for more information.
409: .It Fl M Cm screen
410: Screen candidate parameters for Diffie-Hellman Group Exchange.
411: This will accept a list of candidate numbers and test that they are
412: safe (Sophie Germain) primes with acceptable group generators.
413: The results of this operation may be added to the
414: .Pa /etc/moduli
415: file.
416: See the
417: .Sx MODULI GENERATION
418: section for more information.
1.95 djm 419: .It Fl m Ar key_format
1.155 djm 420: Specify a key format for key generation, the
1.95 djm 421: .Fl i
1.155 djm 422: (import),
1.95 djm 423: .Fl e
1.155 djm 424: (export) conversion options, and the
425: .Fl p
426: change passphrase operation.
427: The latter may be used to convert between OpenSSH private key and PEM
428: private key formats.
1.95 djm 429: The supported key formats are:
430: .Dq RFC4716
1.96 jmc 431: (RFC 4716/SSH2 public or private key),
1.95 djm 432: .Dq PKCS8
1.161 djm 433: (PKCS8 public or private key)
1.95 djm 434: or
435: .Dq PEM
436: (PEM public key).
1.161 djm 437: By default OpenSSH will write newly-generated private keys in its own
438: format, but when converting public keys for export the default format is
1.95 djm 439: .Dq RFC4716 .
1.148 djm 440: Setting a format of
441: .Dq PEM
442: when generating or updating a supported private key type will cause the
443: key to be stored in the legacy PEM private key format.
1.66 jmc 444: .It Fl N Ar new_passphrase
445: Provides the new passphrase.
1.84 djm 446: .It Fl n Ar principals
447: Specify one or more principals (user or host names) to be included in
448: a certificate when signing a key.
449: Multiple principals may be specified, separated by commas.
450: Please see the
451: .Sx CERTIFICATES
452: section for details.
1.93 djm 453: .It Fl O Ar option
1.184 djm 454: Specify a key/value option.
455: These are specific to the operation that
456: .Nm
457: has been requested to perform.
458: .Pp
459: When signing certificates, one of the options listed in the
1.183 djm 460: .Sx CERTIFICATES
1.184 djm 461: section may be specified here.
462: .Pp
463: When performing moduli generation or screening, one of the options
464: listed in the
465: .Sx MODULI GENERATION
466: section may be specified.
467: .Pp
1.190 jmc 468: When generating a key that will be hosted on a FIDO authenticator,
469: this flag may be used to specify key-specific options.
470: Those supported at present are:
471: .Bl -tag -width Ds
472: .It Cm application
473: Override the default FIDO application/origin string of
1.189 djm 474: .Dq ssh: .
1.190 jmc 475: This may be useful when generating host or domain-specific resident keys.
1.200 djm 476: The specified application string must begin with
477: .Dq ssh: .
1.199 jmc 478: .It Cm challenge Ns = Ns Ar path
1.198 jmc 479: Specifies a path to a challenge string that will be passed to the
480: FIDO token during key generation.
1.199 jmc 481: The challenge string may be used as part of an out-of-band
482: protocol for key enrollment
483: (a random challenge is used by default).
1.190 jmc 484: .It Cm device
485: Explicitly specify a
1.189 djm 486: .Xr fido 4
487: device to use, rather than letting the token middleware select one.
1.190 jmc 488: .It Cm no-touch-required
489: Indicate that the generated private key should not require touch
1.185 djm 490: events (user presence) when making signatures.
491: Note that
492: .Xr sshd 8
493: will refuse such signatures by default, unless overridden via
494: an authorized_keys option.
1.190 jmc 495: .It Cm resident
496: Indicate that the key should be stored on the FIDO authenticator itself.
1.185 djm 497: Resident keys may be supported on FIDO2 tokens and typically require that
498: a PIN be set on the token prior to generation.
499: Resident keys may be loaded off the token using
500: .Xr ssh-add 1 .
1.190 jmc 501: .It Cm user
502: A username to be associated with a resident key,
1.189 djm 503: overriding the empty default username.
504: Specifying a username may be useful when generating multiple resident keys
505: for the same application name.
1.199 jmc 506: .It Cm write-attestation Ns = Ns Ar path
1.197 djm 507: May be used at key generation time to record the attestation certificate
508: returned from FIDO tokens during key generation.
509: By default this information is discarded.
1.190 jmc 510: .El
1.185 djm 511: .Pp
512: The
513: .Fl O
514: option may be specified multiple times.
1.66 jmc 515: .It Fl P Ar passphrase
516: Provides the (old) passphrase.
1.2 deraadt 517: .It Fl p
1.1 deraadt 518: Requests changing the passphrase of a private key file instead of
1.12 aaron 519: creating a new private key.
520: The program will prompt for the file
1.1 deraadt 521: containing the private key, for the old passphrase, and twice for the
522: new passphrase.
1.113 jmc 523: .It Fl Q
524: Test whether keys have been revoked in a KRL.
1.203 ! djm 525: If the
! 526: .Fl l
! 527: option is also specified then the contents of the KRL will be printed.
1.5 aaron 528: .It Fl q
529: Silence
530: .Nm ssh-keygen .
1.152 djm 531: .It Fl R Ar hostname | [hostname]:port
1.151 djm 532: Removes all keys belonging to the specified
1.64 djm 533: .Ar hostname
1.151 djm 534: (with optional port number)
1.65 jmc 535: from a
1.64 djm 536: .Pa known_hosts
537: file.
1.65 jmc 538: This option is useful to delete hashed hosts (see the
1.64 djm 539: .Fl H
540: option above).
1.66 jmc 541: .It Fl r Ar hostname
542: Print the SSHFP fingerprint resource record named
543: .Ar hostname
544: for the specified public key file.
1.84 djm 545: .It Fl s Ar ca_key
546: Certify (sign) a public key using the specified CA key.
547: Please see the
548: .Sx CERTIFICATES
549: section for details.
1.111 djm 550: .Pp
551: When generating a KRL,
552: .Fl s
1.112 jmc 553: specifies a path to a CA public key file used to revoke certificates directly
1.111 djm 554: by key ID or serial number.
555: See the
556: .Sx KEY REVOCATION LISTS
557: section for details.
1.175 djm 558: .It Fl t Cm dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa
1.66 jmc 559: Specifies the type of key to create.
560: The possible values are
1.100 naddy 561: .Dq dsa ,
1.118 naddy 562: .Dq ecdsa ,
1.173 naddy 563: .Dq ecdsa-sk ,
1.118 naddy 564: .Dq ed25519 ,
1.175 djm 565: .Dq ed25519-sk ,
1.100 naddy 566: or
1.139 jmc 567: .Dq rsa .
1.159 djm 568: .Pp
569: This flag may also be used to specify the desired signature type when
1.160 jmc 570: signing certificates using an RSA CA key.
1.159 djm 571: The available RSA signature variants are
572: .Dq ssh-rsa
573: (SHA1 signatures, not recommended),
1.160 jmc 574: .Dq rsa-sha2-256 ,
575: and
1.159 djm 576: .Dq rsa-sha2-512
577: (the default).
1.142 djm 578: .It Fl U
579: When used in combination with
580: .Fl s ,
581: this option indicates that a CA key resides in a
582: .Xr ssh-agent 1 .
583: See the
584: .Sx CERTIFICATES
585: section for more information.
1.112 jmc 586: .It Fl u
587: Update a KRL.
588: When specified with
589: .Fl k ,
1.114 jmc 590: keys listed via the command line are added to the existing KRL rather than
1.112 jmc 591: a new KRL being created.
1.84 djm 592: .It Fl V Ar validity_interval
593: Specify a validity interval when signing a certificate.
594: A validity interval may consist of a single time, indicating that the
595: certificate is valid beginning now and expiring at that time, or may consist
596: of two times separated by a colon to indicate an explicit time interval.
1.145 djm 597: .Pp
598: The start time may be specified as the string
599: .Dq always
600: to indicate the certificate has no specified start time,
1.147 djm 601: a date in YYYYMMDD format, a time in YYYYMMDDHHMM[SS] format,
1.145 djm 602: a relative time (to the current time) consisting of a minus sign followed by
603: an interval in the format described in the
1.116 jmc 604: TIME FORMATS section of
1.90 jmc 605: .Xr sshd_config 5 .
1.145 djm 606: .Pp
1.147 djm 607: The end time may be specified as a YYYYMMDD date, a YYYYMMDDHHMM[SS] time,
1.145 djm 608: a relative time starting with a plus character or the string
609: .Dq forever
1.202 dtucker 610: to indicate that the certificate has no expiry date.
1.84 djm 611: .Pp
612: For example:
613: .Dq +52w1d
614: (valid from now to 52 weeks and one day from now),
615: .Dq -4w:+4w
616: (valid from four weeks ago to four weeks from now),
617: .Dq 20100101123000:20110101123000
618: (valid from 12:30 PM, January 1st, 2010 to 12:30 PM, January 1st, 2011),
619: .Dq -1d:20110101
620: (valid from yesterday to midnight, January 1st, 2011).
1.145 djm 621: .Dq -1m:forever
622: (valid from one minute ago and never expiring).
1.61 djm 623: .It Fl v
624: Verbose mode.
625: Causes
626: .Nm
627: to print debugging messages about its progress.
628: This is helpful for debugging moduli generation.
629: Multiple
630: .Fl v
631: options increase the verbosity.
632: The maximum is 3.
1.173 naddy 633: .It Fl w Ar provider
1.180 naddy 634: Specifies a path to a library that will be used when creating
635: FIDO authenticator-hosted keys, overriding the default of using
636: the internal USB HID support.
1.196 djm 637: .It Fl Y Cm find-principals
638: Find the principal(s) associated with the public key of a signature,
1.194 djm 639: provided using the
640: .Fl s
641: flag in an authorized signers file provided using the
642: .Fl f
643: flag.
644: The format of the allowed signers file is documented in the
645: .Sx ALLOWED SIGNERS
1.195 jmc 646: section below.
1.196 djm 647: If one or more matching principals are found, they are returned on
648: standard output.
1.182 jmc 649: .It Fl Y Cm check-novalidate
650: Checks that a signature generated using
651: .Nm
652: .Fl Y Cm sign
653: has a valid structure.
654: This does not validate if a signature comes from an authorized signer.
655: When testing a signature,
656: .Nm
657: accepts a message on standard input and a signature namespace using
658: .Fl n .
659: A file containing the corresponding signature must also be supplied using the
660: .Fl s
661: flag.
662: Successful testing of the signature is signalled by
663: .Nm
664: returning a zero exit status.
1.166 jmc 665: .It Fl Y Cm sign
1.163 djm 666: Cryptographically sign a file or some data using a SSH key.
667: When signing,
668: .Nm
669: accepts zero or more files to sign on the command-line - if no files
670: are specified then
671: .Nm
672: will sign data presented on standard input.
673: Signatures are written to the path of the input file with
674: .Dq .sig
675: appended, or to standard output if the message to be signed was read from
676: standard input.
677: .Pp
678: The key used for signing is specified using the
679: .Fl f
680: option and may refer to either a private key, or a public key with the private
681: half available via
682: .Xr ssh-agent 1 .
683: An additional signature namespace, used to prevent signature confusion across
684: different domains of use (e.g. file signing vs email signing) must be provided
685: via the
686: .Fl n
687: flag.
688: Namespaces are arbitrary strings, and may include:
689: .Dq file
690: for file signing,
691: .Dq email
692: for email signing.
693: For custom uses, it is recommended to use names following a
694: NAMESPACE@YOUR.DOMAIN pattern to generate unambiguous namespaces.
1.166 jmc 695: .It Fl Y Cm verify
1.163 djm 696: Request to verify a signature generated using
697: .Nm
1.166 jmc 698: .Fl Y Cm sign
1.163 djm 699: as described above.
700: When verifying a signature,
701: .Nm
702: accepts a message on standard input and a signature namespace using
703: .Fl n .
704: A file containing the corresponding signature must also be supplied using the
705: .Fl s
706: flag, along with the identity of the signer using
707: .Fl I
708: and a list of allowed signers via the
709: .Fl f
710: flag.
711: The format of the allowed signers file is documented in the
712: .Sx ALLOWED SIGNERS
713: section below.
714: A file containing revoked keys can be passed using the
715: .Fl r
1.165 jmc 716: flag.
717: The revocation file may be a KRL or a one-per-line list of public keys.
1.163 djm 718: Successful verification by an authorized signer is signalled by
719: .Nm
720: returning a zero exit status.
1.181 jmc 721: .It Fl y
722: This option will read a private
723: OpenSSH format file and print an OpenSSH public key to stdout.
1.93 djm 724: .It Fl z Ar serial_number
725: Specifies a serial number to be embedded in the certificate to distinguish
726: this certificate from others from the same CA.
1.156 djm 727: If the
728: .Ar serial_number
729: is prefixed with a
730: .Sq +
731: character, then the serial number will be incremented for each certificate
732: signed on a single command-line.
1.93 djm 733: The default serial number is zero.
1.111 djm 734: .Pp
735: When generating a KRL, the
736: .Fl z
737: flag is used to specify a KRL version number.
1.2 deraadt 738: .El
1.60 djm 739: .Sh MODULI GENERATION
740: .Nm
741: may be used to generate groups for the Diffie-Hellman Group Exchange
742: (DH-GEX) protocol.
743: Generating these groups is a two-step process: first, candidate
744: primes are generated using a fast, but memory intensive process.
745: These candidate primes are then tested for suitability (a CPU-intensive
746: process).
747: .Pp
748: Generation of primes is performed using the
1.184 djm 749: .Fl M Cm generate
1.60 djm 750: option.
751: The desired length of the primes may be specified by the
1.184 djm 752: .Fl O Cm bits
1.60 djm 753: option.
754: For example:
755: .Pp
1.184 djm 756: .Dl # ssh-keygen -M generate -O bits=2048 moduli-2048.candidates
1.60 djm 757: .Pp
758: By default, the search for primes begins at a random point in the
759: desired length range.
760: This may be overridden using the
1.184 djm 761: .Fl O Cm start
1.60 djm 762: option, which specifies a different start point (in hex).
763: .Pp
1.109 dtucker 764: Once a set of candidates have been generated, they must be screened for
1.60 djm 765: suitability.
766: This may be performed using the
1.184 djm 767: .Fl M Cm screen
1.60 djm 768: option.
769: In this mode
770: .Nm
771: will read candidates from standard input (or a file specified using the
772: .Fl f
773: option).
774: For example:
775: .Pp
1.184 djm 776: .Dl # ssh-keygen -M screen -f moduli-2048.candidates moduli-2048
1.60 djm 777: .Pp
778: By default, each candidate will be subjected to 100 primality tests.
779: This may be overridden using the
1.184 djm 780: .Fl O Cm prime-tests
1.60 djm 781: option.
782: The DH generator value will be chosen automatically for the
783: prime under consideration.
784: If a specific generator is desired, it may be requested using the
1.184 djm 785: .Fl O Cm generator
1.60 djm 786: option.
1.66 jmc 787: Valid generator values are 2, 3, and 5.
1.60 djm 788: .Pp
789: Screened DH groups may be installed in
790: .Pa /etc/moduli .
791: It is important that this file contains moduli of a range of bit lengths and
792: that both ends of a connection share common moduli.
1.184 djm 793: .Pp
794: A number of options are available for moduli generation and screening via the
795: .Fl O
796: flag:
1.186 jmc 797: .Bl -tag -width Ds
1.184 djm 798: .It Ic lines Ns = Ns Ar number
799: Exit after screening the specified number of lines while performing DH
800: candidate screening.
801: .It Ic start-line Ns = Ns Ar line-number
802: Start screening at the specified line number while performing DH candidate
803: screening.
804: .It Ic checkpoint Ns = Ns Ar filename
805: Write the last line processed to the specified file while performing DH
806: candidate screening.
807: This will be used to skip lines in the input file that have already been
808: processed if the job is restarted.
809: .It Ic memory Ns = Ns Ar mbytes
810: Specify the amount of memory to use (in megabytes) when generating
811: candidate moduli for DH-GEX.
812: .It Ic start Ns = Ns Ar hex-value
813: Specify start point (in hex) when generating candidate moduli for DH-GEX.
814: .It Ic generator Ns = Ns Ar value
815: Specify desired generator (in decimal) when testing candidate moduli for DH-GEX.
816: .El
1.84 djm 817: .Sh CERTIFICATES
818: .Nm
819: supports signing of keys to produce certificates that may be used for
820: user or host authentication.
821: Certificates consist of a public key, some identity information, zero or
1.94 jmc 822: more principal (user or host) names and a set of options that
1.84 djm 823: are signed by a Certification Authority (CA) key.
824: Clients or servers may then trust only the CA key and verify its signature
825: on a certificate rather than trusting many user/host keys.
826: Note that OpenSSH certificates are a different, and much simpler, format to
827: the X.509 certificates used in
828: .Xr ssl 8 .
829: .Pp
830: .Nm
831: supports two types of certificates: user and host.
832: User certificates authenticate users to servers, whereas host certificates
1.85 jmc 833: authenticate server hosts to users.
834: To generate a user certificate:
1.84 djm 835: .Pp
836: .Dl $ ssh-keygen -s /path/to/ca_key -I key_id /path/to/user_key.pub
837: .Pp
838: The resultant certificate will be placed in
1.91 djm 839: .Pa /path/to/user_key-cert.pub .
1.84 djm 840: A host certificate requires the
841: .Fl h
842: option:
843: .Pp
844: .Dl $ ssh-keygen -s /path/to/ca_key -I key_id -h /path/to/host_key.pub
845: .Pp
846: The host certificate will be output to
1.91 djm 847: .Pa /path/to/host_key-cert.pub .
1.98 djm 848: .Pp
849: It is possible to sign using a CA key stored in a PKCS#11 token by
850: providing the token library using
851: .Fl D
852: and identifying the CA key by providing its public half as an argument
853: to
854: .Fl s :
855: .Pp
1.127 naddy 856: .Dl $ ssh-keygen -s ca_key.pub -D libpkcs11.so -I key_id user_key.pub
1.142 djm 857: .Pp
858: Similarly, it is possible for the CA key to be hosted in a
859: .Xr ssh-agent 1 .
860: This is indicated by the
861: .Fl U
862: flag and, again, the CA key must be identified by its public half.
863: .Pp
864: .Dl $ ssh-keygen -Us ca_key.pub -I key_id user_key.pub
1.98 djm 865: .Pp
866: In all cases,
1.84 djm 867: .Ar key_id
868: is a "key identifier" that is logged by the server when the certificate
869: is used for authentication.
870: .Pp
871: Certificates may be limited to be valid for a set of principal (user/host)
872: names.
873: By default, generated certificates are valid for all users or hosts.
874: To generate a certificate for a specified set of principals:
875: .Pp
876: .Dl $ ssh-keygen -s ca_key -I key_id -n user1,user2 user_key.pub
1.127 naddy 877: .Dl "$ ssh-keygen -s ca_key -I key_id -h -n host.domain host_key.pub"
1.84 djm 878: .Pp
879: Additional limitations on the validity and use of user certificates may
1.94 jmc 880: be specified through certificate options.
1.93 djm 881: A certificate option may disable features of the SSH session, may be
1.84 djm 882: valid only when presented from particular source addresses or may
883: force the use of a specific command.
1.183 djm 884: .Pp
885: The options that are valid for user certificates are:
886: .Pp
887: .Bl -tag -width Ds -compact
888: .It Ic clear
889: Clear all enabled permissions.
890: This is useful for clearing the default set of permissions so permissions may
891: be added individually.
892: .Pp
893: .It Ic critical : Ns Ar name Ns Op Ns = Ns Ar contents
894: .It Ic extension : Ns Ar name Ns Op Ns = Ns Ar contents
895: Includes an arbitrary certificate critical option or extension.
896: The specified
897: .Ar name
898: should include a domain suffix, e.g.\&
899: .Dq name@example.com .
900: If
901: .Ar contents
902: is specified then it is included as the contents of the extension/option
903: encoded as a string, otherwise the extension/option is created with no
904: contents (usually indicating a flag).
905: Extensions may be ignored by a client or server that does not recognise them,
906: whereas unknown critical options will cause the certificate to be refused.
907: .Pp
908: .It Ic force-command Ns = Ns Ar command
909: Forces the execution of
910: .Ar command
911: instead of any shell or command specified by the user when
912: the certificate is used for authentication.
913: .Pp
914: .It Ic no-agent-forwarding
915: Disable
916: .Xr ssh-agent 1
917: forwarding (permitted by default).
918: .Pp
919: .It Ic no-port-forwarding
920: Disable port forwarding (permitted by default).
921: .Pp
922: .It Ic no-pty
923: Disable PTY allocation (permitted by default).
924: .Pp
925: .It Ic no-user-rc
926: Disable execution of
927: .Pa ~/.ssh/rc
928: by
929: .Xr sshd 8
930: (permitted by default).
931: .Pp
932: .It Ic no-x11-forwarding
933: Disable X11 forwarding (permitted by default).
934: .Pp
935: .It Ic permit-agent-forwarding
936: Allows
937: .Xr ssh-agent 1
938: forwarding.
939: .Pp
940: .It Ic permit-port-forwarding
941: Allows port forwarding.
942: .Pp
943: .It Ic permit-pty
944: Allows PTY allocation.
945: .Pp
946: .It Ic permit-user-rc
947: Allows execution of
948: .Pa ~/.ssh/rc
949: by
950: .Xr sshd 8 .
951: .Pp
952: .It Ic permit-X11-forwarding
953: Allows X11 forwarding.
954: .Pp
955: .It Ic no-touch-required
956: Do not require signatures made using this key require demonstration
1.193 naddy 957: of user presence (e.g. by having the user touch the authenticator).
1.192 naddy 958: This option only makes sense for the FIDO authenticator algorithms
1.183 djm 959: .Cm ecdsa-sk
960: and
961: .Cm ed25519-sk .
962: .Pp
963: .It Ic source-address Ns = Ns Ar address_list
964: Restrict the source addresses from which the certificate is considered valid.
965: The
966: .Ar address_list
967: is a comma-separated list of one or more address/netmask pairs in CIDR
968: format.
969: .El
970: .Pp
971: At present, no standard options are valid for host keys.
1.84 djm 972: .Pp
973: Finally, certificates may be defined with a validity lifetime.
974: The
975: .Fl V
976: option allows specification of certificate start and end times.
977: A certificate that is presented at a time outside this range will not be
978: considered valid.
1.110 jmc 979: By default, certificates are valid from
980: .Ux
981: Epoch to the distant future.
1.84 djm 982: .Pp
983: For certificates to be used for user or host authentication, the CA
984: public key must be trusted by
985: .Xr sshd 8
986: or
987: .Xr ssh 1 .
988: Please refer to those manual pages for details.
1.111 djm 989: .Sh KEY REVOCATION LISTS
990: .Nm
991: is able to manage OpenSSH format Key Revocation Lists (KRLs).
992: These binary files specify keys or certificates to be revoked using a
1.119 tedu 993: compact format, taking as little as one bit per certificate if they are being
1.111 djm 994: revoked by serial number.
995: .Pp
996: KRLs may be generated using the
997: .Fl k
998: flag.
1.114 jmc 999: This option reads one or more files from the command line and generates a new
1.111 djm 1000: KRL.
1001: The files may either contain a KRL specification (see below) or public keys,
1002: listed one per line.
1003: Plain public keys are revoked by listing their hash or contents in the KRL and
1004: certificates revoked by serial number or key ID (if the serial is zero or
1005: not available).
1006: .Pp
1007: Revoking keys using a KRL specification offers explicit control over the
1008: types of record used to revoke keys and may be used to directly revoke
1009: certificates by serial number or key ID without having the complete original
1010: certificate on hand.
1011: A KRL specification consists of lines containing one of the following directives
1012: followed by a colon and some directive-specific information.
1013: .Bl -tag -width Ds
1.115 jmc 1014: .It Cm serial : Ar serial_number Ns Op - Ns Ar serial_number
1.111 djm 1015: Revokes a certificate with the specified serial number.
1.112 jmc 1016: Serial numbers are 64-bit values, not including zero and may be expressed
1.111 djm 1017: in decimal, hex or octal.
1018: If two serial numbers are specified separated by a hyphen, then the range
1019: of serial numbers including and between each is revoked.
1020: The CA key must have been specified on the
1021: .Nm
1.114 jmc 1022: command line using the
1.111 djm 1023: .Fl s
1024: option.
1025: .It Cm id : Ar key_id
1026: Revokes a certificate with the specified key ID string.
1027: The CA key must have been specified on the
1028: .Nm
1.114 jmc 1029: command line using the
1.111 djm 1030: .Fl s
1031: option.
1032: .It Cm key : Ar public_key
1033: Revokes the specified key.
1.112 jmc 1034: If a certificate is listed, then it is revoked as a plain public key.
1.111 djm 1035: .It Cm sha1 : Ar public_key
1.149 djm 1036: Revokes the specified key by including its SHA1 hash in the KRL.
1037: .It Cm sha256 : Ar public_key
1038: Revokes the specified key by including its SHA256 hash in the KRL.
1039: KRLs that revoke keys by SHA256 hash are not supported by OpenSSH versions
1040: prior to 7.9.
1041: .It Cm hash : Ar fingerprint
1.150 djm 1042: Revokes a key using a fingerprint hash, as obtained from a
1.149 djm 1043: .Xr sshd 8
1044: authentication log message or the
1045: .Nm
1046: .Fl l
1047: flag.
1048: Only SHA256 fingerprints are supported here and resultant KRLs are
1049: not supported by OpenSSH versions prior to 7.9.
1.111 djm 1050: .El
1051: .Pp
1052: KRLs may be updated using the
1053: .Fl u
1054: flag in addition to
1055: .Fl k .
1.114 jmc 1056: When this option is specified, keys listed via the command line are merged into
1.111 djm 1057: the KRL, adding to those already there.
1058: .Pp
1059: It is also possible, given a KRL, to test whether it revokes a particular key
1060: (or keys).
1061: The
1062: .Fl Q
1.128 jmc 1063: flag will query an existing KRL, testing each key specified on the command line.
1.114 jmc 1064: If any key listed on the command line has been revoked (or an error encountered)
1.111 djm 1065: then
1066: .Nm
1067: will exit with a non-zero exit status.
1068: A zero exit status will only be returned if no key was revoked.
1.163 djm 1069: .Sh ALLOWED SIGNERS
1070: When verifying signatures,
1071: .Nm
1072: uses a simple list of identities and keys to determine whether a signature
1073: comes from an authorized source.
1074: This "allowed signers" file uses a format patterned after the
1075: AUTHORIZED_KEYS FILE FORMAT described in
1.165 jmc 1076: .Xr sshd 8 .
1.163 djm 1077: Each line of the file contains the following space-separated fields:
1078: principals, options, keytype, base64-encoded key.
1079: Empty lines and lines starting with a
1080: .Ql #
1081: are ignored as comments.
1082: .Pp
1083: The principals field is a pattern-list (See PATTERNS in
1084: .Xr ssh_config 5 )
1085: consisting of one or more comma-separated USER@DOMAIN identity patterns
1086: that are accepted for signing.
1087: When verifying, the identity presented via the
1.172 jmc 1088: .Fl I
1089: option must match a principals pattern in order for the corresponding key to be
1.163 djm 1090: considered acceptable for verification.
1091: .Pp
1092: The options (if present) consist of comma-separated option specifications.
1093: No spaces are permitted, except within double quotes.
1094: The following option specifications are supported (note that option keywords
1095: are case-insensitive):
1096: .Bl -tag -width Ds
1097: .It Cm cert-authority
1098: Indicates that this key is accepted as a certificate authority (CA) and
1099: that certificates signed by this CA may be accepted for verification.
1100: .It Cm namespaces="namespace-list"
1101: Specifies a pattern-list of namespaces that are accepted for this key.
1.164 djm 1102: If this option is present, the signature namespace embedded in the
1.163 djm 1103: signature object and presented on the verification command-line must
1104: match the specified list before the key will be considered acceptable.
1105: .El
1106: .Pp
1107: When verifying signatures made by certificates, the expected principal
1108: name must match both the principals pattern in the allowed signers file and
1109: the principals embedded in the certificate itself.
1110: .Pp
1111: An example allowed signers file:
1112: .Bd -literal -offset 3n
1113: # Comments allowed at start of line
1114: user1@example.com,user2@example.com ssh-rsa AAAAX1...
1115: # A certificate authority, trusted for all principals in a domain.
1116: *@example.com cert-authority ssh-ed25519 AAAB4...
1117: # A key that is accepted only for file signing.
1118: user2@example.com namespaces="file" ssh-ed25519 AAA41...
1119: .Ed
1.173 naddy 1120: .Sh ENVIRONMENT
1121: .Bl -tag -width Ds
1122: .It Ev SSH_SK_PROVIDER
1.201 djm 1123: Specifies a path to a library that will be used when loading any
1124: FIDO authenticator-hosted keys, overriding the default of using
1125: the built-in USB HID support.
1.173 naddy 1126: .El
1.2 deraadt 1127: .Sh FILES
1.100 naddy 1128: .Bl -tag -width Ds -compact
1.68 djm 1129: .It Pa ~/.ssh/id_dsa
1.100 naddy 1130: .It Pa ~/.ssh/id_ecdsa
1.173 naddy 1131: .It Pa ~/.ssh/id_ecdsa_sk
1.118 naddy 1132: .It Pa ~/.ssh/id_ed25519
1.176 naddy 1133: .It Pa ~/.ssh/id_ed25519_sk
1.100 naddy 1134: .It Pa ~/.ssh/id_rsa
1.180 naddy 1135: Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
1136: authenticator-hosted Ed25519 or RSA authentication identity of the user.
1.15 deraadt 1137: This file should not be readable by anyone but the user.
1138: It is possible to
1139: specify a passphrase when generating the key; that passphrase will be
1.80 dtucker 1140: used to encrypt the private part of this file using 128-bit AES.
1.15 deraadt 1141: This file is not automatically accessed by
1142: .Nm
1143: but it is offered as the default file for the private key.
1.46 markus 1144: .Xr ssh 1
1.15 deraadt 1145: will read this file when a login attempt is made.
1.100 naddy 1146: .Pp
1.68 djm 1147: .It Pa ~/.ssh/id_dsa.pub
1.100 naddy 1148: .It Pa ~/.ssh/id_ecdsa.pub
1.173 naddy 1149: .It Pa ~/.ssh/id_ecdsa_sk.pub
1.118 naddy 1150: .It Pa ~/.ssh/id_ed25519.pub
1.176 naddy 1151: .It Pa ~/.ssh/id_ed25519_sk.pub
1.68 djm 1152: .It Pa ~/.ssh/id_rsa.pub
1.180 naddy 1153: Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519,
1154: authenticator-hosted Ed25519 or RSA public key for authentication.
1.15 deraadt 1155: The contents of this file should be added to
1.68 djm 1156: .Pa ~/.ssh/authorized_keys
1.15 deraadt 1157: on all machines
1.49 deraadt 1158: where the user wishes to log in using public key authentication.
1.12 aaron 1159: There is no need to keep the contents of this file secret.
1.100 naddy 1160: .Pp
1.60 djm 1161: .It Pa /etc/moduli
1162: Contains Diffie-Hellman groups used for DH-GEX.
1163: The file format is described in
1164: .Xr moduli 5 .
1.19 aaron 1165: .El
1.2 deraadt 1166: .Sh SEE ALSO
1167: .Xr ssh 1 ,
1168: .Xr ssh-add 1 ,
1.8 ericj 1169: .Xr ssh-agent 1 ,
1.60 djm 1170: .Xr moduli 5 ,
1.30 itojun 1171: .Xr sshd 8
1.37 markus 1172: .Rs
1.73 markus 1173: .%R RFC 4716
1174: .%T "The Secure Shell (SSH) Public Key File Format"
1175: .%D 2006
1.37 markus 1176: .Re
1.59 jmc 1177: .Sh AUTHORS
1178: OpenSSH is a derivative of the original and free
1179: ssh 1.2.12 release by Tatu Ylonen.
1180: Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
1181: Theo de Raadt and Dug Song
1182: removed many bugs, re-added newer features and
1183: created OpenSSH.
1184: Markus Friedl contributed the support for SSH
1185: protocol versions 1.5 and 2.0.
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