diff options
author | Colin Watson <cjwatson@debian.org> | 2016-12-20 00:22:52 +0000 |
---|---|---|
committer | Colin Watson <cjwatson@debian.org> | 2016-12-20 00:22:52 +0000 |
commit | 971a7653746a6972b907dfe0ce139c06e4a6f482 (patch) | |
tree | 70fb964265d57ae4967be55b75dbb2a122e9b969 /ssh_config.5 | |
parent | a8ed8d256b2e2c05b0c15565a7938028c5192277 (diff) | |
parent | 4a354fc231174901f2629437c2a6e924a2dd6772 (diff) |
Import openssh_7.4p1.orig.tar.gz
Diffstat (limited to 'ssh_config.5')
-rw-r--r-- | ssh_config.5 | 782 |
1 files changed, 343 insertions, 439 deletions
diff --git a/ssh_config.5 b/ssh_config.5 index 7630e7bcb..591365f34 100644 --- a/ssh_config.5 +++ b/ssh_config.5 | |||
@@ -33,8 +33,8 @@ | |||
33 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 33 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
34 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 34 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
35 | .\" | 35 | .\" |
36 | .\" $OpenBSD: ssh_config.5,v 1.236 2016/07/22 07:00:46 djm Exp $ | 36 | .\" $OpenBSD: ssh_config.5,v 1.240 2016/10/15 19:56:25 jmc Exp $ |
37 | .Dd $Mdocdate: July 22 2016 $ | 37 | .Dd $Mdocdate: October 15 2016 $ |
38 | .Dt SSH_CONFIG 5 | 38 | .Dt SSH_CONFIG 5 |
39 | .Os | 39 | .Os |
40 | .Sh NAME | 40 | .Sh NAME |
@@ -62,25 +62,25 @@ system-wide configuration file | |||
62 | For each parameter, the first obtained value | 62 | For each parameter, the first obtained value |
63 | will be used. | 63 | will be used. |
64 | The configuration files contain sections separated by | 64 | The configuration files contain sections separated by |
65 | .Dq Host | 65 | .Cm Host |
66 | specifications, and that section is only applied for hosts that | 66 | specifications, and that section is only applied for hosts that |
67 | match one of the patterns given in the specification. | 67 | match one of the patterns given in the specification. |
68 | The matched host name is usually the one given on the command line | 68 | The matched host name is usually the one given on the command line |
69 | (see the | 69 | (see the |
70 | .Cm CanonicalizeHostname | 70 | .Cm CanonicalizeHostname |
71 | option for exceptions.) | 71 | option for exceptions). |
72 | .Pp | 72 | .Pp |
73 | Since the first obtained value for each parameter is used, more | 73 | Since the first obtained value for each parameter is used, more |
74 | host-specific declarations should be given near the beginning of the | 74 | host-specific declarations should be given near the beginning of the |
75 | file, and general defaults at the end. | 75 | file, and general defaults at the end. |
76 | .Pp | 76 | .Pp |
77 | The configuration file has the following format: | 77 | The file contains keyword-argument pairs, one per line. |
78 | .Pp | 78 | Lines starting with |
79 | Empty lines and lines starting with | ||
80 | .Ql # | 79 | .Ql # |
81 | are comments. | 80 | and empty lines are interpreted as comments. |
82 | Otherwise a line is of the format | 81 | Arguments may optionally be enclosed in double quotes |
83 | .Dq keyword arguments . | 82 | .Pq \&" |
83 | in order to represent arguments containing spaces. | ||
84 | Configuration options may be separated by whitespace or | 84 | Configuration options may be separated by whitespace or |
85 | optional whitespace and exactly one | 85 | optional whitespace and exactly one |
86 | .Ql = ; | 86 | .Ql = ; |
@@ -92,9 +92,6 @@ and | |||
92 | .Nm sftp | 92 | .Nm sftp |
93 | .Fl o | 93 | .Fl o |
94 | option. | 94 | option. |
95 | Arguments may optionally be enclosed in double quotes | ||
96 | .Pq \&" | ||
97 | in order to represent arguments containing spaces. | ||
98 | .Pp | 95 | .Pp |
99 | The possible | 96 | The possible |
100 | keywords and their meanings are as follows (note that | 97 | keywords and their meanings are as follows (note that |
@@ -117,7 +114,7 @@ The host is usually the | |||
117 | argument given on the command line | 114 | argument given on the command line |
118 | (see the | 115 | (see the |
119 | .Cm CanonicalizeHostname | 116 | .Cm CanonicalizeHostname |
120 | option for exceptions.) | 117 | keyword for exceptions). |
121 | .Pp | 118 | .Pp |
122 | A pattern entry may be negated by prefixing it with an exclamation mark | 119 | A pattern entry may be negated by prefixing it with an exclamation mark |
123 | .Pq Sq !\& . | 120 | .Pq Sq !\& . |
@@ -177,24 +174,11 @@ The | |||
177 | keyword executes the specified command under the user's shell. | 174 | keyword executes the specified command under the user's shell. |
178 | If the command returns a zero exit status then the condition is considered true. | 175 | If the command returns a zero exit status then the condition is considered true. |
179 | Commands containing whitespace characters must be quoted. | 176 | Commands containing whitespace characters must be quoted. |
180 | The following character sequences in the command will be expanded prior to | 177 | Arguments to |
181 | execution: | 178 | .Cm exec |
182 | .Ql %L | 179 | accept the tokens described in the |
183 | will be substituted by the first component of the local host name, | 180 | .Sx TOKENS |
184 | .Ql %l | 181 | section. |
185 | will be substituted by the local host name (including any domain name), | ||
186 | .Ql %h | ||
187 | will be substituted by the target host name, | ||
188 | .Ql %n | ||
189 | will be substituted by the original target host name | ||
190 | specified on the command-line, | ||
191 | .Ql %p | ||
192 | the destination port, | ||
193 | .Ql %r | ||
194 | by the remote login username, and | ||
195 | .Ql %u | ||
196 | by the username of the user running | ||
197 | .Xr ssh 1 . | ||
198 | .Pp | 182 | .Pp |
199 | The other keywords' criteria must be single entries or comma-separated | 183 | The other keywords' criteria must be single entries or comma-separated |
200 | lists and may use the wildcard and negation operators described in the | 184 | lists and may use the wildcard and negation operators described in the |
@@ -225,57 +209,54 @@ files). | |||
225 | Specifies whether keys should be automatically added to a running | 209 | Specifies whether keys should be automatically added to a running |
226 | .Xr ssh-agent 1 . | 210 | .Xr ssh-agent 1 . |
227 | If this option is set to | 211 | If this option is set to |
228 | .Dq yes | 212 | .Cm yes |
229 | and a key is loaded from a file, the key and its passphrase are added to | 213 | and a key is loaded from a file, the key and its passphrase are added to |
230 | the agent with the default lifetime, as if by | 214 | the agent with the default lifetime, as if by |
231 | .Xr ssh-add 1 . | 215 | .Xr ssh-add 1 . |
232 | If this option is set to | 216 | If this option is set to |
233 | .Dq ask , | 217 | .Cm ask , |
234 | .Nm ssh | 218 | .Xr ssh 1 |
235 | will require confirmation using the | 219 | will require confirmation using the |
236 | .Ev SSH_ASKPASS | 220 | .Ev SSH_ASKPASS |
237 | program before adding a key (see | 221 | program before adding a key (see |
238 | .Xr ssh-add 1 | 222 | .Xr ssh-add 1 |
239 | for details). | 223 | for details). |
240 | If this option is set to | 224 | If this option is set to |
241 | .Dq confirm , | 225 | .Cm confirm , |
242 | each use of the key must be confirmed, as if the | 226 | each use of the key must be confirmed, as if the |
243 | .Fl c | 227 | .Fl c |
244 | option was specified to | 228 | option was specified to |
245 | .Xr ssh-add 1 . | 229 | .Xr ssh-add 1 . |
246 | If this option is set to | 230 | If this option is set to |
247 | .Dq no , | 231 | .Cm no , |
248 | no keys are added to the agent. | 232 | no keys are added to the agent. |
249 | The argument must be | 233 | The argument must be |
250 | .Dq yes , | 234 | .Cm yes , |
251 | .Dq confirm , | 235 | .Cm confirm , |
252 | .Dq ask , | 236 | .Cm ask , |
253 | or | 237 | or |
254 | .Dq no . | 238 | .Cm no |
255 | The default is | 239 | (the default). |
256 | .Dq no . | ||
257 | .It Cm AddressFamily | 240 | .It Cm AddressFamily |
258 | Specifies which address family to use when connecting. | 241 | Specifies which address family to use when connecting. |
259 | Valid arguments are | 242 | Valid arguments are |
260 | .Dq any , | 243 | .Cm any |
261 | .Dq inet | 244 | (the default), |
245 | .Cm inet | ||
262 | (use IPv4 only), or | 246 | (use IPv4 only), or |
263 | .Dq inet6 | 247 | .Cm inet6 |
264 | (use IPv6 only). | 248 | (use IPv6 only). |
265 | The default is | ||
266 | .Dq any . | ||
267 | .It Cm BatchMode | 249 | .It Cm BatchMode |
268 | If set to | 250 | If set to |
269 | .Dq yes , | 251 | .Cm yes , |
270 | passphrase/password querying will be disabled. | 252 | passphrase/password querying will be disabled. |
271 | This option is useful in scripts and other batch jobs where no user | 253 | This option is useful in scripts and other batch jobs where no user |
272 | is present to supply the password. | 254 | is present to supply the password. |
273 | The argument must be | 255 | The argument must be |
274 | .Dq yes | 256 | .Cm yes |
275 | or | 257 | or |
276 | .Dq no . | 258 | .Cm no |
277 | The default is | 259 | (the default). |
278 | .Dq no . | ||
279 | .It Cm BindAddress | 260 | .It Cm BindAddress |
280 | Use the specified address on the local machine as the source address of | 261 | Use the specified address on the local machine as the source address of |
281 | the connection. | 262 | the connection. |
@@ -283,7 +264,7 @@ Only useful on systems with more than one address. | |||
283 | Note that this option does not work if | 264 | Note that this option does not work if |
284 | .Cm UsePrivilegedPort | 265 | .Cm UsePrivilegedPort |
285 | is set to | 266 | is set to |
286 | .Dq yes . | 267 | .Cm yes . |
287 | .It Cm CanonicalDomains | 268 | .It Cm CanonicalDomains |
288 | When | 269 | When |
289 | .Cm CanonicalizeHostname | 270 | .Cm CanonicalizeHostname |
@@ -292,11 +273,11 @@ search for the specified destination host. | |||
292 | .It Cm CanonicalizeFallbackLocal | 273 | .It Cm CanonicalizeFallbackLocal |
293 | Specifies whether to fail with an error when hostname canonicalization fails. | 274 | Specifies whether to fail with an error when hostname canonicalization fails. |
294 | The default, | 275 | The default, |
295 | .Dq yes , | 276 | .Cm yes , |
296 | will attempt to look up the unqualified hostname using the system resolver's | 277 | will attempt to look up the unqualified hostname using the system resolver's |
297 | search rules. | 278 | search rules. |
298 | A value of | 279 | A value of |
299 | .Dq no | 280 | .Cm no |
300 | will cause | 281 | will cause |
301 | .Xr ssh 1 | 282 | .Xr ssh 1 |
302 | to fail instantly if | 283 | to fail instantly if |
@@ -307,11 +288,11 @@ specified by | |||
307 | .It Cm CanonicalizeHostname | 288 | .It Cm CanonicalizeHostname |
308 | Controls whether explicit hostname canonicalization is performed. | 289 | Controls whether explicit hostname canonicalization is performed. |
309 | The default, | 290 | The default, |
310 | .Dq no , | 291 | .Cm no , |
311 | is not to perform any name rewriting and let the system resolver handle all | 292 | is not to perform any name rewriting and let the system resolver handle all |
312 | hostname lookups. | 293 | hostname lookups. |
313 | If set to | 294 | If set to |
314 | .Dq yes | 295 | .Cm yes |
315 | then, for connections that do not use a | 296 | then, for connections that do not use a |
316 | .Cm ProxyCommand , | 297 | .Cm ProxyCommand , |
317 | .Xr ssh 1 | 298 | .Xr ssh 1 |
@@ -324,7 +305,7 @@ rules. | |||
324 | If | 305 | If |
325 | .Cm CanonicalizeHostname | 306 | .Cm CanonicalizeHostname |
326 | is set to | 307 | is set to |
327 | .Dq always , | 308 | .Cm always , |
328 | then canonicalization is applied to proxied connections too. | 309 | then canonicalization is applied to proxied connections too. |
329 | .Pp | 310 | .Pp |
330 | If this option is enabled, then the configuration files are processed | 311 | If this option is enabled, then the configuration files are processed |
@@ -336,8 +317,7 @@ stanzas. | |||
336 | .It Cm CanonicalizeMaxDots | 317 | .It Cm CanonicalizeMaxDots |
337 | Specifies the maximum number of dot characters in a hostname before | 318 | Specifies the maximum number of dot characters in a hostname before |
338 | canonicalization is disabled. | 319 | canonicalization is disabled. |
339 | The default, | 320 | The default, 1, |
340 | .Dq 1 , | ||
341 | allows a single dot (i.e. hostname.subdomain). | 321 | allows a single dot (i.e. hostname.subdomain). |
342 | .It Cm CanonicalizePermittedCNAMEs | 322 | .It Cm CanonicalizePermittedCNAMEs |
343 | Specifies rules to determine whether CNAMEs should be followed when | 323 | Specifies rules to determine whether CNAMEs should be followed when |
@@ -352,13 +332,13 @@ and | |||
352 | is a pattern-list of domains that they may resolve to. | 332 | is a pattern-list of domains that they may resolve to. |
353 | .Pp | 333 | .Pp |
354 | For example, | 334 | For example, |
355 | .Dq *.a.example.com:*.b.example.com,*.c.example.com | 335 | .Qq *.a.example.com:*.b.example.com,*.c.example.com |
356 | will allow hostnames matching | 336 | will allow hostnames matching |
357 | .Dq *.a.example.com | 337 | .Qq *.a.example.com |
358 | to be canonicalized to names in the | 338 | to be canonicalized to names in the |
359 | .Dq *.b.example.com | 339 | .Qq *.b.example.com |
360 | or | 340 | or |
361 | .Dq *.c.example.com | 341 | .Qq *.c.example.com |
362 | domains. | 342 | domains. |
363 | .It Cm CertificateFile | 343 | .It Cm CertificateFile |
364 | Specifies a file from which the user's certificate is read. | 344 | Specifies a file from which the user's certificate is read. |
@@ -375,19 +355,12 @@ via | |||
375 | or via a | 355 | or via a |
376 | .Cm PKCS11Provider . | 356 | .Cm PKCS11Provider . |
377 | .Pp | 357 | .Pp |
378 | The file name may use the tilde | 358 | Arguments to |
379 | syntax to refer to a user's home directory or one of the following | 359 | .Cm CertificateFile |
380 | escape characters: | 360 | may use the tilde syntax to refer to a user's home directory |
381 | .Ql %d | 361 | or the tokens described in the |
382 | (local user's home directory), | 362 | .Sx TOKENS |
383 | .Ql %u | 363 | section. |
384 | (local user name), | ||
385 | .Ql %l | ||
386 | (local host name), | ||
387 | .Ql %h | ||
388 | (remote host name) or | ||
389 | .Ql %r | ||
390 | (remote user name). | ||
391 | .Pp | 364 | .Pp |
392 | It is possible to have multiple certificate files specified in | 365 | It is possible to have multiple certificate files specified in |
393 | configuration files; these certificates will be tried in sequence. | 366 | configuration files; these certificates will be tried in sequence. |
@@ -398,47 +371,42 @@ authentication. | |||
398 | .It Cm ChallengeResponseAuthentication | 371 | .It Cm ChallengeResponseAuthentication |
399 | Specifies whether to use challenge-response authentication. | 372 | Specifies whether to use challenge-response authentication. |
400 | The argument to this keyword must be | 373 | The argument to this keyword must be |
401 | .Dq yes | 374 | .Cm yes |
375 | (the default) | ||
402 | or | 376 | or |
403 | .Dq no . | 377 | .Cm no . |
404 | The default is | ||
405 | .Dq yes . | ||
406 | .It Cm CheckHostIP | 378 | .It Cm CheckHostIP |
407 | If this flag is set to | 379 | If set to |
408 | .Dq yes , | 380 | .Cm yes |
381 | (the default), | ||
409 | .Xr ssh 1 | 382 | .Xr ssh 1 |
410 | will additionally check the host IP address in the | 383 | will additionally check the host IP address in the |
411 | .Pa known_hosts | 384 | .Pa known_hosts |
412 | file. | 385 | file. |
413 | This allows ssh to detect if a host key changed due to DNS spoofing | 386 | This allows it to detect if a host key changed due to DNS spoofing |
414 | and will add addresses of destination hosts to | 387 | and will add addresses of destination hosts to |
415 | .Pa ~/.ssh/known_hosts | 388 | .Pa ~/.ssh/known_hosts |
416 | in the process, regardless of the setting of | 389 | in the process, regardless of the setting of |
417 | .Cm StrictHostKeyChecking . | 390 | .Cm StrictHostKeyChecking . |
418 | If the option is set to | 391 | If the option is set to |
419 | .Dq no , | 392 | .Cm no , |
420 | the check will not be executed. | 393 | the check will not be executed. |
421 | The default is | ||
422 | .Dq yes . | ||
423 | .It Cm Cipher | 394 | .It Cm Cipher |
424 | Specifies the cipher to use for encrypting the session | 395 | Specifies the cipher to use for encrypting the session |
425 | in protocol version 1. | 396 | in protocol version 1. |
426 | Currently, | 397 | Currently, |
427 | .Dq blowfish , | 398 | .Cm blowfish , |
428 | .Dq 3des , | 399 | .Cm 3des |
400 | (the default), | ||
429 | and | 401 | and |
430 | .Dq des | 402 | .Cm des |
431 | are supported. | 403 | are supported, |
432 | .Ar des | 404 | though |
405 | .Cm des | ||
433 | is only supported in the | 406 | is only supported in the |
434 | .Xr ssh 1 | 407 | .Xr ssh 1 |
435 | client for interoperability with legacy protocol 1 implementations | 408 | client for interoperability with legacy protocol 1 implementations; |
436 | that do not support the | 409 | its use is strongly discouraged due to cryptographic weaknesses. |
437 | .Ar 3des | ||
438 | cipher. | ||
439 | Its use is strongly discouraged due to cryptographic weaknesses. | ||
440 | The default is | ||
441 | .Dq 3des . | ||
442 | .It Cm Ciphers | 410 | .It Cm Ciphers |
443 | Specifies the ciphers allowed for protocol version 2 | 411 | Specifies the ciphers allowed for protocol version 2 |
444 | in order of preference. | 412 | in order of preference. |
@@ -449,54 +417,34 @@ character, then the specified ciphers will be appended to the default set | |||
449 | instead of replacing them. | 417 | instead of replacing them. |
450 | .Pp | 418 | .Pp |
451 | The supported ciphers are: | 419 | The supported ciphers are: |
452 | .Pp | 420 | .Bd -literal -offset indent |
453 | .Bl -item -compact -offset indent | ||
454 | .It | ||
455 | 3des-cbc | 421 | 3des-cbc |
456 | .It | ||
457 | aes128-cbc | 422 | aes128-cbc |
458 | .It | ||
459 | aes192-cbc | 423 | aes192-cbc |
460 | .It | ||
461 | aes256-cbc | 424 | aes256-cbc |
462 | .It | ||
463 | aes128-ctr | 425 | aes128-ctr |
464 | .It | ||
465 | aes192-ctr | 426 | aes192-ctr |
466 | .It | ||
467 | aes256-ctr | 427 | aes256-ctr |
468 | .It | ||
469 | aes128-gcm@openssh.com | 428 | aes128-gcm@openssh.com |
470 | .It | ||
471 | aes256-gcm@openssh.com | 429 | aes256-gcm@openssh.com |
472 | .It | ||
473 | arcfour | 430 | arcfour |
474 | .It | ||
475 | arcfour128 | 431 | arcfour128 |
476 | .It | ||
477 | arcfour256 | 432 | arcfour256 |
478 | .It | ||
479 | blowfish-cbc | 433 | blowfish-cbc |
480 | .It | ||
481 | cast128-cbc | 434 | cast128-cbc |
482 | .It | ||
483 | chacha20-poly1305@openssh.com | 435 | chacha20-poly1305@openssh.com |
484 | .El | 436 | .Ed |
485 | .Pp | 437 | .Pp |
486 | The default is: | 438 | The default is: |
487 | .Bd -literal -offset indent | 439 | .Bd -literal -offset indent |
488 | chacha20-poly1305@openssh.com, | 440 | chacha20-poly1305@openssh.com, |
489 | aes128-ctr,aes192-ctr,aes256-ctr, | 441 | aes128-ctr,aes192-ctr,aes256-ctr, |
490 | aes128-gcm@openssh.com,aes256-gcm@openssh.com, | 442 | aes128-gcm@openssh.com,aes256-gcm@openssh.com, |
491 | aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc | 443 | aes128-cbc,aes192-cbc,aes256-cbc |
492 | .Ed | 444 | .Ed |
493 | .Pp | 445 | .Pp |
494 | The list of available ciphers may also be obtained using the | 446 | The list of available ciphers may also be obtained using |
495 | .Fl Q | 447 | .Qq ssh -Q cipher . |
496 | option of | ||
497 | .Xr ssh 1 | ||
498 | with an argument of | ||
499 | .Dq cipher . | ||
500 | .It Cm ClearAllForwardings | 448 | .It Cm ClearAllForwardings |
501 | Specifies that all local, remote, and dynamic port forwardings | 449 | Specifies that all local, remote, and dynamic port forwardings |
502 | specified in the configuration files or on the command line be | 450 | specified in the configuration files or on the command line be |
@@ -509,19 +457,17 @@ configuration files, and is automatically set by | |||
509 | and | 457 | and |
510 | .Xr sftp 1 . | 458 | .Xr sftp 1 . |
511 | The argument must be | 459 | The argument must be |
512 | .Dq yes | 460 | .Cm yes |
513 | or | 461 | or |
514 | .Dq no . | 462 | .Cm no |
515 | The default is | 463 | (the default). |
516 | .Dq no . | ||
517 | .It Cm Compression | 464 | .It Cm Compression |
518 | Specifies whether to use compression. | 465 | Specifies whether to use compression. |
519 | The argument must be | 466 | The argument must be |
520 | .Dq yes | 467 | .Cm yes |
521 | or | 468 | or |
522 | .Dq no . | 469 | .Cm no |
523 | The default is | 470 | (the default). |
524 | .Dq no . | ||
525 | .It Cm CompressionLevel | 471 | .It Cm CompressionLevel |
526 | Specifies the compression level to use if compression is enabled. | 472 | Specifies the compression level to use if compression is enabled. |
527 | The argument must be an integer from 1 (fast) to 9 (slow, best). | 473 | The argument must be an integer from 1 (fast) to 9 (slow, best). |
@@ -542,7 +488,7 @@ not when it refuses the connection. | |||
542 | .It Cm ControlMaster | 488 | .It Cm ControlMaster |
543 | Enables the sharing of multiple sessions over a single network connection. | 489 | Enables the sharing of multiple sessions over a single network connection. |
544 | When set to | 490 | When set to |
545 | .Dq yes , | 491 | .Cm yes , |
546 | .Xr ssh 1 | 492 | .Xr ssh 1 |
547 | will listen for connections on a control socket specified using the | 493 | will listen for connections on a control socket specified using the |
548 | .Cm ControlPath | 494 | .Cm ControlPath |
@@ -552,21 +498,23 @@ Additional sessions can connect to this socket using the same | |||
552 | with | 498 | with |
553 | .Cm ControlMaster | 499 | .Cm ControlMaster |
554 | set to | 500 | set to |
555 | .Dq no | 501 | .Cm no |
556 | (the default). | 502 | (the default). |
557 | These sessions will try to reuse the master instance's network connection | 503 | These sessions will try to reuse the master instance's network connection |
558 | rather than initiating new ones, but will fall back to connecting normally | 504 | rather than initiating new ones, but will fall back to connecting normally |
559 | if the control socket does not exist, or is not listening. | 505 | if the control socket does not exist, or is not listening. |
560 | .Pp | 506 | .Pp |
561 | Setting this to | 507 | Setting this to |
562 | .Dq ask | 508 | .Cm ask |
563 | will cause ssh | 509 | will cause |
510 | .Xr ssh 1 | ||
564 | to listen for control connections, but require confirmation using | 511 | to listen for control connections, but require confirmation using |
565 | .Xr ssh-askpass 1 . | 512 | .Xr ssh-askpass 1 . |
566 | If the | 513 | If the |
567 | .Cm ControlPath | 514 | .Cm ControlPath |
568 | cannot be opened, | 515 | cannot be opened, |
569 | ssh will continue without connecting to a master instance. | 516 | .Xr ssh 1 |
517 | will continue without connecting to a master instance. | ||
570 | .Pp | 518 | .Pp |
571 | X11 and | 519 | X11 and |
572 | .Xr ssh-agent 1 | 520 | .Xr ssh-agent 1 |
@@ -578,41 +526,25 @@ Two additional options allow for opportunistic multiplexing: try to use a | |||
578 | master connection but fall back to creating a new one if one does not already | 526 | master connection but fall back to creating a new one if one does not already |
579 | exist. | 527 | exist. |
580 | These options are: | 528 | These options are: |
581 | .Dq auto | 529 | .Cm auto |
582 | and | 530 | and |
583 | .Dq autoask . | 531 | .Cm autoask . |
584 | The latter requires confirmation like the | 532 | The latter requires confirmation like the |
585 | .Dq ask | 533 | .Cm ask |
586 | option. | 534 | option. |
587 | .It Cm ControlPath | 535 | .It Cm ControlPath |
588 | Specify the path to the control socket used for connection sharing as described | 536 | Specify the path to the control socket used for connection sharing as described |
589 | in the | 537 | in the |
590 | .Cm ControlMaster | 538 | .Cm ControlMaster |
591 | section above or the string | 539 | section above or the string |
592 | .Dq none | 540 | .Cm none |
593 | to disable connection sharing. | 541 | to disable connection sharing. |
594 | In the path, | 542 | Arguments to |
595 | .Ql %L | 543 | .Cm ControlPath |
596 | will be substituted by the first component of the local host name, | 544 | may use the tilde syntax to refer to a user's home directory |
597 | .Ql %l | 545 | or the tokens described in the |
598 | will be substituted by the local host name (including any domain name), | 546 | .Sx TOKENS |
599 | .Ql %h | 547 | section. |
600 | will be substituted by the target host name, | ||
601 | .Ql %n | ||
602 | will be substituted by the original target host name | ||
603 | specified on the command line, | ||
604 | .Ql %p | ||
605 | the destination port, | ||
606 | .Ql %r | ||
607 | by the remote login username, | ||
608 | .Ql %u | ||
609 | by the username and | ||
610 | .Ql %i | ||
611 | by the numeric user ID (uid) of the user running | ||
612 | .Xr ssh 1 , | ||
613 | and | ||
614 | .Ql \&%C | ||
615 | by a hash of the concatenation: %l%h%p%r. | ||
616 | It is recommended that any | 548 | It is recommended that any |
617 | .Cm ControlPath | 549 | .Cm ControlPath |
618 | used for opportunistic connection sharing include | 550 | used for opportunistic connection sharing include |
@@ -626,18 +558,15 @@ specifies that the master connection should remain open | |||
626 | in the background (waiting for future client connections) | 558 | in the background (waiting for future client connections) |
627 | after the initial client connection has been closed. | 559 | after the initial client connection has been closed. |
628 | If set to | 560 | If set to |
629 | .Dq no , | 561 | .Cm no , |
630 | then the master connection will not be placed into the background, | 562 | then the master connection will not be placed into the background, |
631 | and will close as soon as the initial client connection is closed. | 563 | and will close as soon as the initial client connection is closed. |
632 | If set to | 564 | If set to |
633 | .Dq yes | 565 | .Cm yes |
634 | or | 566 | or 0, |
635 | .Dq 0 , | ||
636 | then the master connection will remain in the background indefinitely | 567 | then the master connection will remain in the background indefinitely |
637 | (until killed or closed via a mechanism such as the | 568 | (until killed or closed via a mechanism such as the |
638 | .Xr ssh 1 | 569 | .Qq ssh -O exit ) . |
639 | .Dq Fl O No exit | ||
640 | option). | ||
641 | If set to a time in seconds, or a time in any of the formats documented in | 570 | If set to a time in seconds, or a time in any of the formats documented in |
642 | .Xr sshd_config 5 , | 571 | .Xr sshd_config 5 , |
643 | then the backgrounded master connection will automatically terminate | 572 | then the backgrounded master connection will automatically terminate |
@@ -663,7 +592,7 @@ may be used to bind the connection to a specific address. | |||
663 | The | 592 | The |
664 | .Ar bind_address | 593 | .Ar bind_address |
665 | of | 594 | of |
666 | .Dq localhost | 595 | .Cm localhost |
667 | indicates that the listening port be bound for local use only, while an | 596 | indicates that the listening port be bound for local use only, while an |
668 | empty address or | 597 | empty address or |
669 | .Sq * | 598 | .Sq * |
@@ -677,7 +606,7 @@ additional forwardings can be given on the command line. | |||
677 | Only the superuser can forward privileged ports. | 606 | Only the superuser can forward privileged ports. |
678 | .It Cm EnableSSHKeysign | 607 | .It Cm EnableSSHKeysign |
679 | Setting this option to | 608 | Setting this option to |
680 | .Dq yes | 609 | .Cm yes |
681 | in the global client configuration file | 610 | in the global client configuration file |
682 | .Pa /etc/ssh/ssh_config | 611 | .Pa /etc/ssh/ssh_config |
683 | enables the use of the helper program | 612 | enables the use of the helper program |
@@ -685,11 +614,10 @@ enables the use of the helper program | |||
685 | during | 614 | during |
686 | .Cm HostbasedAuthentication . | 615 | .Cm HostbasedAuthentication . |
687 | The argument must be | 616 | The argument must be |
688 | .Dq yes | 617 | .Cm yes |
689 | or | 618 | or |
690 | .Dq no . | 619 | .Cm no |
691 | The default is | 620 | (the default). |
692 | .Dq no . | ||
693 | This option should be placed in the non-hostspecific section. | 621 | This option should be placed in the non-hostspecific section. |
694 | See | 622 | See |
695 | .Xr ssh-keysign 8 | 623 | .Xr ssh-keysign 8 |
@@ -702,7 +630,7 @@ be set on the command line. | |||
702 | The argument should be a single character, | 630 | The argument should be a single character, |
703 | .Ql ^ | 631 | .Ql ^ |
704 | followed by a letter, or | 632 | followed by a letter, or |
705 | .Dq none | 633 | .Cm none |
706 | to disable the escape | 634 | to disable the escape |
707 | character entirely (making the connection transparent for binary | 635 | character entirely (making the connection transparent for binary |
708 | data). | 636 | data). |
@@ -719,28 +647,25 @@ for example, cause | |||
719 | .Xr ssh 1 | 647 | .Xr ssh 1 |
720 | to exit if TCP connections to the ultimate forwarding destination fail. | 648 | to exit if TCP connections to the ultimate forwarding destination fail. |
721 | The argument must be | 649 | The argument must be |
722 | .Dq yes | 650 | .Cm yes |
723 | or | 651 | or |
724 | .Dq no . | 652 | .Cm no |
725 | The default is | 653 | (the default). |
726 | .Dq no . | ||
727 | .It Cm FingerprintHash | 654 | .It Cm FingerprintHash |
728 | Specifies the hash algorithm used when displaying key fingerprints. | 655 | Specifies the hash algorithm used when displaying key fingerprints. |
729 | Valid options are: | 656 | Valid options are: |
730 | .Dq md5 | 657 | .Cm md5 |
731 | and | 658 | and |
732 | .Dq sha256 . | 659 | .Cm sha256 |
733 | The default is | 660 | (the default). |
734 | .Dq sha256 . | ||
735 | .It Cm ForwardAgent | 661 | .It Cm ForwardAgent |
736 | Specifies whether the connection to the authentication agent (if any) | 662 | Specifies whether the connection to the authentication agent (if any) |
737 | will be forwarded to the remote machine. | 663 | will be forwarded to the remote machine. |
738 | The argument must be | 664 | The argument must be |
739 | .Dq yes | 665 | .Cm yes |
740 | or | 666 | or |
741 | .Dq no . | 667 | .Cm no |
742 | The default is | 668 | (the default). |
743 | .Dq no . | ||
744 | .Pp | 669 | .Pp |
745 | Agent forwarding should be enabled with caution. | 670 | Agent forwarding should be enabled with caution. |
746 | Users with the ability to bypass file permissions on the remote host | 671 | Users with the ability to bypass file permissions on the remote host |
@@ -755,11 +680,10 @@ over the secure channel and | |||
755 | .Ev DISPLAY | 680 | .Ev DISPLAY |
756 | set. | 681 | set. |
757 | The argument must be | 682 | The argument must be |
758 | .Dq yes | 683 | .Cm yes |
759 | or | 684 | or |
760 | .Dq no . | 685 | .Cm no |
761 | The default is | 686 | (the default). |
762 | .Dq no . | ||
763 | .Pp | 687 | .Pp |
764 | X11 forwarding should be enabled with caution. | 688 | X11 forwarding should be enabled with caution. |
765 | Users with the ability to bypass file permissions on the remote host | 689 | Users with the ability to bypass file permissions on the remote host |
@@ -772,7 +696,8 @@ option is also enabled. | |||
772 | .It Cm ForwardX11Timeout | 696 | .It Cm ForwardX11Timeout |
773 | Specify a timeout for untrusted X11 forwarding | 697 | Specify a timeout for untrusted X11 forwarding |
774 | using the format described in the | 698 | using the format described in the |
775 | TIME FORMATS section of | 699 | .Sx TIME FORMATS |
700 | section of | ||
776 | .Xr sshd_config 5 . | 701 | .Xr sshd_config 5 . |
777 | X11 connections received by | 702 | X11 connections received by |
778 | .Xr ssh 1 | 703 | .Xr ssh 1 |
@@ -781,11 +706,12 @@ The default is to disable untrusted X11 forwarding after twenty minutes has | |||
781 | elapsed. | 706 | elapsed. |
782 | .It Cm ForwardX11Trusted | 707 | .It Cm ForwardX11Trusted |
783 | If this option is set to | 708 | If this option is set to |
784 | .Dq yes , | 709 | .Cm yes , |
785 | remote X11 clients will have full access to the original X11 display. | 710 | remote X11 clients will have full access to the original X11 display. |
786 | .Pp | 711 | .Pp |
787 | If this option is set to | 712 | If this option is set to |
788 | .Dq no , | 713 | .Cm no |
714 | (the default), | ||
789 | remote X11 clients will be considered untrusted and prevented | 715 | remote X11 clients will be considered untrusted and prevented |
790 | from stealing or tampering with data belonging to trusted X11 | 716 | from stealing or tampering with data belonging to trusted X11 |
791 | clients. | 717 | clients. |
@@ -794,9 +720,6 @@ Furthermore, the | |||
794 | token used for the session will be set to expire after 20 minutes. | 720 | token used for the session will be set to expire after 20 minutes. |
795 | Remote clients will be refused access after this time. | 721 | Remote clients will be refused access after this time. |
796 | .Pp | 722 | .Pp |
797 | The default is | ||
798 | .Dq no . | ||
799 | .Pp | ||
800 | See the X11 SECURITY extension specification for full details on | 723 | See the X11 SECURITY extension specification for full details on |
801 | the restrictions imposed on untrusted clients. | 724 | the restrictions imposed on untrusted clients. |
802 | .It Cm GatewayPorts | 725 | .It Cm GatewayPorts |
@@ -811,11 +734,10 @@ can be used to specify that ssh | |||
811 | should bind local port forwardings to the wildcard address, | 734 | should bind local port forwardings to the wildcard address, |
812 | thus allowing remote hosts to connect to forwarded ports. | 735 | thus allowing remote hosts to connect to forwarded ports. |
813 | The argument must be | 736 | The argument must be |
814 | .Dq yes | 737 | .Cm yes |
815 | or | 738 | or |
816 | .Dq no . | 739 | .Cm no |
817 | The default is | 740 | (the default). |
818 | .Dq no . | ||
819 | .It Cm GlobalKnownHostsFile | 741 | .It Cm GlobalKnownHostsFile |
820 | Specifies one or more files to use for the global | 742 | Specifies one or more files to use for the global |
821 | host key database, separated by whitespace. | 743 | host key database, separated by whitespace. |
@@ -825,11 +747,11 @@ The default is | |||
825 | .It Cm GSSAPIAuthentication | 747 | .It Cm GSSAPIAuthentication |
826 | Specifies whether user authentication based on GSSAPI is allowed. | 748 | Specifies whether user authentication based on GSSAPI is allowed. |
827 | The default is | 749 | The default is |
828 | .Dq no . | 750 | .Cm no . |
829 | .It Cm GSSAPIDelegateCredentials | 751 | .It Cm GSSAPIDelegateCredentials |
830 | Forward (delegate) credentials to the server. | 752 | Forward (delegate) credentials to the server. |
831 | The default is | 753 | The default is |
832 | .Dq no . | 754 | .Cm no . |
833 | .It Cm HashKnownHosts | 755 | .It Cm HashKnownHosts |
834 | Indicates that | 756 | Indicates that |
835 | .Xr ssh 1 | 757 | .Xr ssh 1 |
@@ -842,7 +764,7 @@ and | |||
842 | but they do not reveal identifying information should the file's contents | 764 | but they do not reveal identifying information should the file's contents |
843 | be disclosed. | 765 | be disclosed. |
844 | The default is | 766 | The default is |
845 | .Dq no . | 767 | .Cm no . |
846 | Note that existing names and addresses in known hosts files | 768 | Note that existing names and addresses in known hosts files |
847 | will not be converted automatically, | 769 | will not be converted automatically, |
848 | but may be manually hashed using | 770 | but may be manually hashed using |
@@ -851,11 +773,10 @@ but may be manually hashed using | |||
851 | Specifies whether to try rhosts based authentication with public key | 773 | Specifies whether to try rhosts based authentication with public key |
852 | authentication. | 774 | authentication. |
853 | The argument must be | 775 | The argument must be |
854 | .Dq yes | 776 | .Cm yes |
855 | or | 777 | or |
856 | .Dq no . | 778 | .Cm no |
857 | The default is | 779 | (the default). |
858 | .Dq no . | ||
859 | .It Cm HostbasedKeyTypes | 780 | .It Cm HostbasedKeyTypes |
860 | Specifies the key types that will be used for hostbased authentication | 781 | Specifies the key types that will be used for hostbased authentication |
861 | as a comma-separated pattern list. | 782 | as a comma-separated pattern list. |
@@ -900,12 +821,8 @@ ssh-ed25519,ssh-rsa | |||
900 | If hostkeys are known for the destination host then this default is modified | 821 | If hostkeys are known for the destination host then this default is modified |
901 | to prefer their algorithms. | 822 | to prefer their algorithms. |
902 | .Pp | 823 | .Pp |
903 | The list of available key types may also be obtained using the | 824 | The list of available key types may also be obtained using |
904 | .Fl Q | 825 | .Qq ssh -Q key . |
905 | option of | ||
906 | .Xr ssh 1 | ||
907 | with an argument of | ||
908 | .Dq key . | ||
909 | .It Cm HostKeyAlias | 826 | .It Cm HostKeyAlias |
910 | Specifies an alias that should be used instead of the | 827 | Specifies an alias that should be used instead of the |
911 | real host name when looking up or saving the host key | 828 | real host name when looking up or saving the host key |
@@ -915,20 +832,15 @@ or for multiple servers running on a single host. | |||
915 | .It Cm HostName | 832 | .It Cm HostName |
916 | Specifies the real host name to log into. | 833 | Specifies the real host name to log into. |
917 | This can be used to specify nicknames or abbreviations for hosts. | 834 | This can be used to specify nicknames or abbreviations for hosts. |
918 | If the hostname contains the character sequence | 835 | Arguments to |
919 | .Ql %h , | 836 | .Cm HostName |
920 | then this will be replaced with the host name specified on the command line | 837 | accept the tokens described in the |
921 | (this is useful for manipulating unqualified names). | 838 | .Sx TOKENS |
922 | The character sequence | 839 | section. |
923 | .Ql %% | ||
924 | will be replaced by a single | ||
925 | .Ql % | ||
926 | character, which may be used when specifying IPv6 link-local addresses. | ||
927 | .Pp | ||
928 | The default is the name given on the command line. | ||
929 | Numeric IP addresses are also permitted (both on the command line and in | 840 | Numeric IP addresses are also permitted (both on the command line and in |
930 | .Cm HostName | 841 | .Cm HostName |
931 | specifications). | 842 | specifications). |
843 | The default is the name given on the command line. | ||
932 | .It Cm IdentitiesOnly | 844 | .It Cm IdentitiesOnly |
933 | Specifies that | 845 | Specifies that |
934 | .Xr ssh 1 | 846 | .Xr ssh 1 |
@@ -945,43 +857,35 @@ or a | |||
945 | .Cm PKCS11Provider | 857 | .Cm PKCS11Provider |
946 | offers more identities. | 858 | offers more identities. |
947 | The argument to this keyword must be | 859 | The argument to this keyword must be |
948 | .Dq yes | 860 | .Cm yes |
949 | or | 861 | or |
950 | .Dq no . | 862 | .Cm no |
863 | (the default). | ||
951 | This option is intended for situations where ssh-agent | 864 | This option is intended for situations where ssh-agent |
952 | offers many different identities. | 865 | offers many different identities. |
953 | The default is | ||
954 | .Dq no . | ||
955 | .It Cm IdentityAgent | 866 | .It Cm IdentityAgent |
956 | Specifies the | 867 | Specifies the |
957 | .Ux Ns -domain | 868 | .Ux Ns -domain |
958 | socket used to communicate with the authentication agent. | 869 | socket used to communicate with the authentication agent. |
959 | .Pp | 870 | .Pp |
960 | This option overrides the | 871 | This option overrides the |
961 | .Dq SSH_AUTH_SOCK | 872 | .Ev SSH_AUTH_SOCK |
962 | environment variable and can be used to select a specific agent. | 873 | environment variable and can be used to select a specific agent. |
963 | Setting the socket name to | 874 | Setting the socket name to |
964 | .Dq none | 875 | .Cm none |
965 | disables the use of an authentication agent. | 876 | disables the use of an authentication agent. |
966 | If the string | 877 | If the string |
967 | .Dq SSH_AUTH_SOCK | 878 | .Qq SSH_AUTH_SOCK |
968 | is specified, the location of the socket will be read from the | 879 | is specified, the location of the socket will be read from the |
969 | .Ev SSH_AUTH_SOCK | 880 | .Ev SSH_AUTH_SOCK |
970 | environment variable. | 881 | environment variable. |
971 | .Pp | 882 | .Pp |
972 | The socket name may use the tilde | 883 | Arguments to |
973 | syntax to refer to a user's home directory or one of the following | 884 | .Cm IdentityAgent |
974 | escape characters: | 885 | may use the tilde syntax to refer to a user's home directory |
975 | .Ql %d | 886 | or the tokens described in the |
976 | (local user's home directory), | 887 | .Sx TOKENS |
977 | .Ql %u | 888 | section. |
978 | (local user name), | ||
979 | .Ql %l | ||
980 | (local host name), | ||
981 | .Ql %h | ||
982 | (remote host name) or | ||
983 | .Ql %r | ||
984 | (remote user name). | ||
985 | .It Cm IdentityFile | 889 | .It Cm IdentityFile |
986 | Specifies a file from which the user's DSA, ECDSA, Ed25519 or RSA authentication | 890 | Specifies a file from which the user's DSA, ECDSA, Ed25519 or RSA authentication |
987 | identity is read. | 891 | identity is read. |
@@ -1007,19 +911,12 @@ appending | |||
1007 | to the path of a specified | 911 | to the path of a specified |
1008 | .Cm IdentityFile . | 912 | .Cm IdentityFile . |
1009 | .Pp | 913 | .Pp |
1010 | The file name may use the tilde | 914 | Arguments to |
1011 | syntax to refer to a user's home directory or one of the following | 915 | .Cm IdentityFile |
1012 | escape characters: | 916 | may use the tilde syntax to refer to a user's home directory |
1013 | .Ql %d | 917 | or the tokens described in the |
1014 | (local user's home directory), | 918 | .Sx TOKENS |
1015 | .Ql %u | 919 | section. |
1016 | (local user name), | ||
1017 | .Ql %l | ||
1018 | (local host name), | ||
1019 | .Ql %h | ||
1020 | (remote host name) or | ||
1021 | .Ql %r | ||
1022 | (remote user name). | ||
1023 | .Pp | 920 | .Pp |
1024 | It is possible to have | 921 | It is possible to have |
1025 | multiple identity files specified in configuration files; all these | 922 | multiple identity files specified in configuration files; all these |
@@ -1054,7 +951,7 @@ Include the specified configuration file(s). | |||
1054 | Multiple pathnames may be specified and each pathname may contain | 951 | Multiple pathnames may be specified and each pathname may contain |
1055 | .Xr glob 3 | 952 | .Xr glob 3 |
1056 | wildcards and, for user configurations, shell-like | 953 | wildcards and, for user configurations, shell-like |
1057 | .Dq ~ | 954 | .Sq ~ |
1058 | references to user home directories. | 955 | references to user home directories. |
1059 | Files without absolute paths are assumed to be in | 956 | Files without absolute paths are assumed to be in |
1060 | .Pa ~/.ssh | 957 | .Pa ~/.ssh |
@@ -1071,48 +968,47 @@ to perform conditional inclusion. | |||
1071 | .It Cm IPQoS | 968 | .It Cm IPQoS |
1072 | Specifies the IPv4 type-of-service or DSCP class for connections. | 969 | Specifies the IPv4 type-of-service or DSCP class for connections. |
1073 | Accepted values are | 970 | Accepted values are |
1074 | .Dq af11 , | 971 | .Cm af11 , |
1075 | .Dq af12 , | 972 | .Cm af12 , |
1076 | .Dq af13 , | 973 | .Cm af13 , |
1077 | .Dq af21 , | 974 | .Cm af21 , |
1078 | .Dq af22 , | 975 | .Cm af22 , |
1079 | .Dq af23 , | 976 | .Cm af23 , |
1080 | .Dq af31 , | 977 | .Cm af31 , |
1081 | .Dq af32 , | 978 | .Cm af32 , |
1082 | .Dq af33 , | 979 | .Cm af33 , |
1083 | .Dq af41 , | 980 | .Cm af41 , |
1084 | .Dq af42 , | 981 | .Cm af42 , |
1085 | .Dq af43 , | 982 | .Cm af43 , |
1086 | .Dq cs0 , | 983 | .Cm cs0 , |
1087 | .Dq cs1 , | 984 | .Cm cs1 , |
1088 | .Dq cs2 , | 985 | .Cm cs2 , |
1089 | .Dq cs3 , | 986 | .Cm cs3 , |
1090 | .Dq cs4 , | 987 | .Cm cs4 , |
1091 | .Dq cs5 , | 988 | .Cm cs5 , |
1092 | .Dq cs6 , | 989 | .Cm cs6 , |
1093 | .Dq cs7 , | 990 | .Cm cs7 , |
1094 | .Dq ef , | 991 | .Cm ef , |
1095 | .Dq lowdelay , | 992 | .Cm lowdelay , |
1096 | .Dq throughput , | 993 | .Cm throughput , |
1097 | .Dq reliability , | 994 | .Cm reliability , |
1098 | or a numeric value. | 995 | or a numeric value. |
1099 | This option may take one or two arguments, separated by whitespace. | 996 | This option may take one or two arguments, separated by whitespace. |
1100 | If one argument is specified, it is used as the packet class unconditionally. | 997 | If one argument is specified, it is used as the packet class unconditionally. |
1101 | If two values are specified, the first is automatically selected for | 998 | If two values are specified, the first is automatically selected for |
1102 | interactive sessions and the second for non-interactive sessions. | 999 | interactive sessions and the second for non-interactive sessions. |
1103 | The default is | 1000 | The default is |
1104 | .Dq lowdelay | 1001 | .Cm lowdelay |
1105 | for interactive sessions and | 1002 | for interactive sessions and |
1106 | .Dq throughput | 1003 | .Cm throughput |
1107 | for non-interactive sessions. | 1004 | for non-interactive sessions. |
1108 | .It Cm KbdInteractiveAuthentication | 1005 | .It Cm KbdInteractiveAuthentication |
1109 | Specifies whether to use keyboard-interactive authentication. | 1006 | Specifies whether to use keyboard-interactive authentication. |
1110 | The argument to this keyword must be | 1007 | The argument to this keyword must be |
1111 | .Dq yes | 1008 | .Cm yes |
1009 | (the default) | ||
1112 | or | 1010 | or |
1113 | .Dq no . | 1011 | .Cm no . |
1114 | The default is | ||
1115 | .Dq yes . | ||
1116 | .It Cm KbdInteractiveDevices | 1012 | .It Cm KbdInteractiveDevices |
1117 | Specifies the list of methods to use in keyboard-interactive authentication. | 1013 | Specifies the list of methods to use in keyboard-interactive authentication. |
1118 | Multiple method names must be comma-separated. | 1014 | Multiple method names must be comma-separated. |
@@ -1120,10 +1016,10 @@ The default is to use the server specified list. | |||
1120 | The methods available vary depending on what the server supports. | 1016 | The methods available vary depending on what the server supports. |
1121 | For an OpenSSH server, | 1017 | For an OpenSSH server, |
1122 | it may be zero or more of: | 1018 | it may be zero or more of: |
1123 | .Dq bsdauth , | 1019 | .Cm bsdauth , |
1124 | .Dq pam , | 1020 | .Cm pam , |
1125 | and | 1021 | and |
1126 | .Dq skey . | 1022 | .Cm skey . |
1127 | .It Cm KexAlgorithms | 1023 | .It Cm KexAlgorithms |
1128 | Specifies the available KEX (Key Exchange) algorithms. | 1024 | Specifies the available KEX (Key Exchange) algorithms. |
1129 | Multiple algorithms must be comma-separated. | 1025 | Multiple algorithms must be comma-separated. |
@@ -1133,41 +1029,25 @@ character, then the specified methods will be appended to the default set | |||
1133 | instead of replacing them. | 1029 | instead of replacing them. |
1134 | The default is: | 1030 | The default is: |
1135 | .Bd -literal -offset indent | 1031 | .Bd -literal -offset indent |
1136 | curve25519-sha256@libssh.org, | 1032 | curve25519-sha256,curve25519-sha256@libssh.org, |
1137 | ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521, | 1033 | ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521, |
1138 | diffie-hellman-group-exchange-sha256, | 1034 | diffie-hellman-group-exchange-sha256, |
1139 | diffie-hellman-group-exchange-sha1, | 1035 | diffie-hellman-group-exchange-sha1, |
1140 | diffie-hellman-group14-sha1 | 1036 | diffie-hellman-group14-sha1 |
1141 | .Ed | 1037 | .Ed |
1142 | .Pp | 1038 | .Pp |
1143 | The list of available key exchange algorithms may also be obtained using the | 1039 | The list of available key exchange algorithms may also be obtained using |
1144 | .Fl Q | 1040 | .Qq ssh -Q kex . |
1145 | option of | ||
1146 | .Xr ssh 1 | ||
1147 | with an argument of | ||
1148 | .Dq kex . | ||
1149 | .It Cm LocalCommand | 1041 | .It Cm LocalCommand |
1150 | Specifies a command to execute on the local machine after successfully | 1042 | Specifies a command to execute on the local machine after successfully |
1151 | connecting to the server. | 1043 | connecting to the server. |
1152 | The command string extends to the end of the line, and is executed with | 1044 | The command string extends to the end of the line, and is executed with |
1153 | the user's shell. | 1045 | the user's shell. |
1154 | The following escape character substitutions will be performed: | 1046 | Arguments to |
1155 | .Ql %d | 1047 | .Cm LocalCommand |
1156 | (local user's home directory), | 1048 | accept the tokens described in the |
1157 | .Ql %h | 1049 | .Sx TOKENS |
1158 | (remote host name), | 1050 | section. |
1159 | .Ql %l | ||
1160 | (local host name), | ||
1161 | .Ql %n | ||
1162 | (host name as provided on the command line), | ||
1163 | .Ql %p | ||
1164 | (remote port), | ||
1165 | .Ql %r | ||
1166 | (remote user name) or | ||
1167 | .Ql %u | ||
1168 | (local user name) or | ||
1169 | .Ql \&%C | ||
1170 | by a hash of the concatenation: %l%h%p%r. | ||
1171 | .Pp | 1051 | .Pp |
1172 | The command is run synchronously and does not have access to the | 1052 | The command is run synchronously and does not have access to the |
1173 | session of the | 1053 | session of the |
@@ -1200,7 +1080,7 @@ may be used to bind the connection to a specific address. | |||
1200 | The | 1080 | The |
1201 | .Ar bind_address | 1081 | .Ar bind_address |
1202 | of | 1082 | of |
1203 | .Dq localhost | 1083 | .Cm localhost |
1204 | indicates that the listening port be bound for local use only, while an | 1084 | indicates that the listening port be bound for local use only, while an |
1205 | empty address or | 1085 | empty address or |
1206 | .Sq * | 1086 | .Sq * |
@@ -1224,7 +1104,7 @@ character, then the specified algorithms will be appended to the default set | |||
1224 | instead of replacing them. | 1104 | instead of replacing them. |
1225 | .Pp | 1105 | .Pp |
1226 | The algorithms that contain | 1106 | The algorithms that contain |
1227 | .Dq -etm | 1107 | .Qq -etm |
1228 | calculate the MAC after encryption (encrypt-then-mac). | 1108 | calculate the MAC after encryption (encrypt-then-mac). |
1229 | These are considered safer and their use recommended. | 1109 | These are considered safer and their use recommended. |
1230 | .Pp | 1110 | .Pp |
@@ -1237,22 +1117,18 @@ umac-64@openssh.com,umac-128@openssh.com, | |||
1237 | hmac-sha2-256,hmac-sha2-512,hmac-sha1 | 1117 | hmac-sha2-256,hmac-sha2-512,hmac-sha1 |
1238 | .Ed | 1118 | .Ed |
1239 | .Pp | 1119 | .Pp |
1240 | The list of available MAC algorithms may also be obtained using the | 1120 | The list of available MAC algorithms may also be obtained using |
1241 | .Fl Q | 1121 | .Qq ssh -Q mac . |
1242 | option of | ||
1243 | .Xr ssh 1 | ||
1244 | with an argument of | ||
1245 | .Dq mac . | ||
1246 | .It Cm NoHostAuthenticationForLocalhost | 1122 | .It Cm NoHostAuthenticationForLocalhost |
1247 | This option can be used if the home directory is shared across machines. | 1123 | This option can be used if the home directory is shared across machines. |
1248 | In this case localhost will refer to a different machine on each of | 1124 | In this case localhost will refer to a different machine on each of |
1249 | the machines and the user will get many warnings about changed host keys. | 1125 | the machines and the user will get many warnings about changed host keys. |
1250 | However, this option disables host authentication for localhost. | 1126 | However, this option disables host authentication for localhost. |
1251 | The argument to this keyword must be | 1127 | The argument to this keyword must be |
1252 | .Dq yes | 1128 | .Cm yes |
1253 | or | 1129 | or |
1254 | .Dq no . | 1130 | .Cm no . |
1255 | The default is to check the host key for localhost. | 1131 | (the default). |
1256 | .It Cm NumberOfPasswordPrompts | 1132 | .It Cm NumberOfPasswordPrompts |
1257 | Specifies the number of password prompts before giving up. | 1133 | Specifies the number of password prompts before giving up. |
1258 | The argument to this keyword must be an integer. | 1134 | The argument to this keyword must be an integer. |
@@ -1260,11 +1136,10 @@ The default is 3. | |||
1260 | .It Cm PasswordAuthentication | 1136 | .It Cm PasswordAuthentication |
1261 | Specifies whether to use password authentication. | 1137 | Specifies whether to use password authentication. |
1262 | The argument to this keyword must be | 1138 | The argument to this keyword must be |
1263 | .Dq yes | 1139 | .Cm yes |
1140 | (the default) | ||
1264 | or | 1141 | or |
1265 | .Dq no . | 1142 | .Cm no . |
1266 | The default is | ||
1267 | .Dq yes . | ||
1268 | .It Cm PermitLocalCommand | 1143 | .It Cm PermitLocalCommand |
1269 | Allow local command execution via the | 1144 | Allow local command execution via the |
1270 | .Ic LocalCommand | 1145 | .Ic LocalCommand |
@@ -1273,11 +1148,10 @@ option or using the | |||
1273 | escape sequence in | 1148 | escape sequence in |
1274 | .Xr ssh 1 . | 1149 | .Xr ssh 1 . |
1275 | The argument must be | 1150 | The argument must be |
1276 | .Dq yes | 1151 | .Cm yes |
1277 | or | 1152 | or |
1278 | .Dq no . | 1153 | .Cm no |
1279 | The default is | 1154 | (the default). |
1280 | .Dq no . | ||
1281 | .It Cm PKCS11Provider | 1155 | .It Cm PKCS11Provider |
1282 | Specifies which PKCS#11 provider to use. | 1156 | Specifies which PKCS#11 provider to use. |
1283 | The argument to this keyword is the PKCS#11 shared library | 1157 | The argument to this keyword is the PKCS#11 shared library |
@@ -1302,18 +1176,14 @@ keyboard-interactive,password | |||
1302 | Specifies the protocol versions | 1176 | Specifies the protocol versions |
1303 | .Xr ssh 1 | 1177 | .Xr ssh 1 |
1304 | should support in order of preference. | 1178 | should support in order of preference. |
1305 | The possible values are | 1179 | The possible values are 1 and 2. |
1306 | .Sq 1 | ||
1307 | and | ||
1308 | .Sq 2 . | ||
1309 | Multiple versions must be comma-separated. | 1180 | Multiple versions must be comma-separated. |
1310 | When this option is set to | 1181 | When this option is set to |
1311 | .Dq 2,1 | 1182 | .Cm 2,1 |
1312 | .Nm ssh | 1183 | .Nm ssh |
1313 | will try version 2 and fall back to version 1 | 1184 | will try version 2 and fall back to version 1 |
1314 | if version 2 is not available. | 1185 | if version 2 is not available. |
1315 | The default is | 1186 | The default is version 2. |
1316 | .Sq 2 . | ||
1317 | Protocol 1 suffers from a number of cryptographic weaknesses and should | 1187 | Protocol 1 suffers from a number of cryptographic weaknesses and should |
1318 | not be used. | 1188 | not be used. |
1319 | It is only offered to support legacy devices. | 1189 | It is only offered to support legacy devices. |
@@ -1325,14 +1195,11 @@ using the user's shell | |||
1325 | .Ql exec | 1195 | .Ql exec |
1326 | directive to avoid a lingering shell process. | 1196 | directive to avoid a lingering shell process. |
1327 | .Pp | 1197 | .Pp |
1328 | In the command string, any occurrence of | 1198 | Arguments to |
1329 | .Ql %h | 1199 | .Cm ProxyCommand |
1330 | will be substituted by the host name to | 1200 | accept the tokens described in the |
1331 | connect, | 1201 | .Sx TOKENS |
1332 | .Ql %p | 1202 | section. |
1333 | by the port, and | ||
1334 | .Ql %r | ||
1335 | by the remote user name. | ||
1336 | The command can be basically anything, | 1203 | The command can be basically anything, |
1337 | and should read from its standard input and write to its standard output. | 1204 | and should read from its standard input and write to its standard output. |
1338 | It should eventually connect an | 1205 | It should eventually connect an |
@@ -1344,7 +1211,7 @@ Host key management will be done using the | |||
1344 | HostName of the host being connected (defaulting to the name typed by | 1211 | HostName of the host being connected (defaulting to the name typed by |
1345 | the user). | 1212 | the user). |
1346 | Setting the command to | 1213 | Setting the command to |
1347 | .Dq none | 1214 | .Cm none |
1348 | disables this option entirely. | 1215 | disables this option entirely. |
1349 | Note that | 1216 | Note that |
1350 | .Cm CheckHostIP | 1217 | .Cm CheckHostIP |
@@ -1389,7 +1256,7 @@ will pass a connected file descriptor back to | |||
1389 | .Xr ssh 1 | 1256 | .Xr ssh 1 |
1390 | instead of continuing to execute and pass data. | 1257 | instead of continuing to execute and pass data. |
1391 | The default is | 1258 | The default is |
1392 | .Dq no . | 1259 | .Cm no . |
1393 | .It Cm PubkeyAcceptedKeyTypes | 1260 | .It Cm PubkeyAcceptedKeyTypes |
1394 | Specifies the key types that will be used for public key authentication | 1261 | Specifies the key types that will be used for public key authentication |
1395 | as a comma-separated pattern list. | 1262 | as a comma-separated pattern list. |
@@ -1408,19 +1275,15 @@ ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, | |||
1408 | ssh-ed25519,ssh-rsa | 1275 | ssh-ed25519,ssh-rsa |
1409 | .Ed | 1276 | .Ed |
1410 | .Pp | 1277 | .Pp |
1411 | The | 1278 | The list of available key types may also be obtained using |
1412 | .Fl Q | 1279 | .Qq ssh -Q key . |
1413 | option of | ||
1414 | .Xr ssh 1 | ||
1415 | may be used to list supported key types. | ||
1416 | .It Cm PubkeyAuthentication | 1280 | .It Cm PubkeyAuthentication |
1417 | Specifies whether to try public key authentication. | 1281 | Specifies whether to try public key authentication. |
1418 | The argument to this keyword must be | 1282 | The argument to this keyword must be |
1419 | .Dq yes | 1283 | .Cm yes |
1284 | (the default) | ||
1420 | or | 1285 | or |
1421 | .Dq no . | 1286 | .Cm no . |
1422 | The default is | ||
1423 | .Dq yes . | ||
1424 | .It Cm RekeyLimit | 1287 | .It Cm RekeyLimit |
1425 | Specifies the maximum amount of data that may be transmitted before the | 1288 | Specifies the maximum amount of data that may be transmitted before the |
1426 | session key is renegotiated, optionally followed a maximum amount of | 1289 | session key is renegotiated, optionally followed a maximum amount of |
@@ -1438,12 +1301,13 @@ and | |||
1438 | depending on the cipher. | 1301 | depending on the cipher. |
1439 | The optional second value is specified in seconds and may use any of the | 1302 | The optional second value is specified in seconds and may use any of the |
1440 | units documented in the | 1303 | units documented in the |
1441 | TIME FORMATS section of | 1304 | .Sx TIME FORMATS |
1305 | section of | ||
1442 | .Xr sshd_config 5 . | 1306 | .Xr sshd_config 5 . |
1443 | The default value for | 1307 | The default value for |
1444 | .Cm RekeyLimit | 1308 | .Cm RekeyLimit |
1445 | is | 1309 | is |
1446 | .Dq default none , | 1310 | .Cm default none , |
1447 | which means that rekeying is performed after the cipher's default amount | 1311 | which means that rekeying is performed after the cipher's default amount |
1448 | of data has been sent or received and no time based rekeying is done. | 1312 | of data has been sent or received and no time based rekeying is done. |
1449 | .It Cm RemoteForward | 1313 | .It Cm RemoteForward |
@@ -1463,8 +1327,7 @@ logging in as root on the remote machine. | |||
1463 | .Pp | 1327 | .Pp |
1464 | If the | 1328 | If the |
1465 | .Ar port | 1329 | .Ar port |
1466 | argument is | 1330 | argument is 0, |
1467 | .Ql 0 , | ||
1468 | the listen port will be dynamically allocated on the server and reported | 1331 | the listen port will be dynamically allocated on the server and reported |
1469 | to the client at run time. | 1332 | to the client at run time. |
1470 | .Pp | 1333 | .Pp |
@@ -1486,13 +1349,13 @@ option is enabled (see | |||
1486 | .It Cm RequestTTY | 1349 | .It Cm RequestTTY |
1487 | Specifies whether to request a pseudo-tty for the session. | 1350 | Specifies whether to request a pseudo-tty for the session. |
1488 | The argument may be one of: | 1351 | The argument may be one of: |
1489 | .Dq no | 1352 | .Cm no |
1490 | (never request a TTY), | 1353 | (never request a TTY), |
1491 | .Dq yes | 1354 | .Cm yes |
1492 | (always request a TTY when standard input is a TTY), | 1355 | (always request a TTY when standard input is a TTY), |
1493 | .Dq force | 1356 | .Cm force |
1494 | (always request a TTY) or | 1357 | (always request a TTY) or |
1495 | .Dq auto | 1358 | .Cm auto |
1496 | (request a TTY when opening a login session). | 1359 | (request a TTY when opening a login session). |
1497 | This option mirrors the | 1360 | This option mirrors the |
1498 | .Fl t | 1361 | .Fl t |
@@ -1514,25 +1377,23 @@ For more information on KRLs, see the KEY REVOCATION LISTS section in | |||
1514 | Specifies whether to try rhosts based authentication with RSA host | 1377 | Specifies whether to try rhosts based authentication with RSA host |
1515 | authentication. | 1378 | authentication. |
1516 | The argument must be | 1379 | The argument must be |
1517 | .Dq yes | 1380 | .Cm yes |
1518 | or | 1381 | or |
1519 | .Dq no . | 1382 | .Cm no |
1520 | The default is | 1383 | (the default). |
1521 | .Dq no . | ||
1522 | This option applies to protocol version 1 only and requires | 1384 | This option applies to protocol version 1 only and requires |
1523 | .Xr ssh 1 | 1385 | .Xr ssh 1 |
1524 | to be setuid root. | 1386 | to be setuid root. |
1525 | .It Cm RSAAuthentication | 1387 | .It Cm RSAAuthentication |
1526 | Specifies whether to try RSA authentication. | 1388 | Specifies whether to try RSA authentication. |
1527 | The argument to this keyword must be | 1389 | The argument to this keyword must be |
1528 | .Dq yes | 1390 | .Cm yes |
1391 | (the default) | ||
1529 | or | 1392 | or |
1530 | .Dq no . | 1393 | .Cm no . |
1531 | RSA authentication will only be | 1394 | RSA authentication will only be |
1532 | attempted if the identity file exists, or an authentication agent is | 1395 | attempted if the identity file exists, or an authentication agent is |
1533 | running. | 1396 | running. |
1534 | The default is | ||
1535 | .Dq yes . | ||
1536 | Note that this option applies to protocol version 1 only. | 1397 | Note that this option applies to protocol version 1 only. |
1537 | .It Cm SendEnv | 1398 | .It Cm SendEnv |
1538 | Specifies what variables from the local | 1399 | Specifies what variables from the local |
@@ -1615,14 +1476,13 @@ will be unable to forward the port to the Unix-domain socket file. | |||
1615 | This option is only used for port forwarding to a Unix-domain socket file. | 1476 | This option is only used for port forwarding to a Unix-domain socket file. |
1616 | .Pp | 1477 | .Pp |
1617 | The argument must be | 1478 | The argument must be |
1618 | .Dq yes | 1479 | .Cm yes |
1619 | or | 1480 | or |
1620 | .Dq no . | 1481 | .Cm no |
1621 | The default is | 1482 | (the default). |
1622 | .Dq no . | ||
1623 | .It Cm StrictHostKeyChecking | 1483 | .It Cm StrictHostKeyChecking |
1624 | If this flag is set to | 1484 | If this flag is set to |
1625 | .Dq yes , | 1485 | .Cm yes , |
1626 | .Xr ssh 1 | 1486 | .Xr ssh 1 |
1627 | will never automatically add host keys to the | 1487 | will never automatically add host keys to the |
1628 | .Pa ~/.ssh/known_hosts | 1488 | .Pa ~/.ssh/known_hosts |
@@ -1635,24 +1495,18 @@ frequently made. | |||
1635 | This option forces the user to manually | 1495 | This option forces the user to manually |
1636 | add all new hosts. | 1496 | add all new hosts. |
1637 | If this flag is set to | 1497 | If this flag is set to |
1638 | .Dq no , | 1498 | .Cm no , |
1639 | ssh will automatically add new host keys to the | 1499 | ssh will automatically add new host keys to the |
1640 | user known hosts files. | 1500 | user known hosts files. |
1641 | If this flag is set to | 1501 | If this flag is set to |
1642 | .Dq ask , | 1502 | .Cm ask |
1503 | (the default), | ||
1643 | new host keys | 1504 | new host keys |
1644 | will be added to the user known host files only after the user | 1505 | will be added to the user known host files only after the user |
1645 | has confirmed that is what they really want to do, and | 1506 | has confirmed that is what they really want to do, and |
1646 | ssh will refuse to connect to hosts whose host key has changed. | 1507 | ssh will refuse to connect to hosts whose host key has changed. |
1647 | The host keys of | 1508 | The host keys of |
1648 | known hosts will be verified automatically in all cases. | 1509 | known hosts will be verified automatically in all cases. |
1649 | The argument must be | ||
1650 | .Dq yes , | ||
1651 | .Dq no , | ||
1652 | or | ||
1653 | .Dq ask . | ||
1654 | The default is | ||
1655 | .Dq ask . | ||
1656 | .It Cm TCPKeepAlive | 1510 | .It Cm TCPKeepAlive |
1657 | Specifies whether the system should send TCP keepalive messages to the | 1511 | Specifies whether the system should send TCP keepalive messages to the |
1658 | other side. | 1512 | other side. |
@@ -1663,31 +1517,30 @@ connections will die if the route is down temporarily, and some people | |||
1663 | find it annoying. | 1517 | find it annoying. |
1664 | .Pp | 1518 | .Pp |
1665 | The default is | 1519 | The default is |
1666 | .Dq yes | 1520 | .Cm yes |
1667 | (to send TCP keepalive messages), and the client will notice | 1521 | (to send TCP keepalive messages), and the client will notice |
1668 | if the network goes down or the remote host dies. | 1522 | if the network goes down or the remote host dies. |
1669 | This is important in scripts, and many users want it too. | 1523 | This is important in scripts, and many users want it too. |
1670 | .Pp | 1524 | .Pp |
1671 | To disable TCP keepalive messages, the value should be set to | 1525 | To disable TCP keepalive messages, the value should be set to |
1672 | .Dq no . | 1526 | .Cm no . |
1673 | .It Cm Tunnel | 1527 | .It Cm Tunnel |
1674 | Request | 1528 | Request |
1675 | .Xr tun 4 | 1529 | .Xr tun 4 |
1676 | device forwarding between the client and the server. | 1530 | device forwarding between the client and the server. |
1677 | The argument must be | 1531 | The argument must be |
1678 | .Dq yes , | 1532 | .Cm yes , |
1679 | .Dq point-to-point | 1533 | .Cm point-to-point |
1680 | (layer 3), | 1534 | (layer 3), |
1681 | .Dq ethernet | 1535 | .Cm ethernet |
1682 | (layer 2), | 1536 | (layer 2), |
1683 | or | 1537 | or |
1684 | .Dq no . | 1538 | .Cm no |
1539 | (the default). | ||
1685 | Specifying | 1540 | Specifying |
1686 | .Dq yes | 1541 | .Cm yes |
1687 | requests the default tunnel mode, which is | 1542 | requests the default tunnel mode, which is |
1688 | .Dq point-to-point . | 1543 | .Cm point-to-point . |
1689 | The default is | ||
1690 | .Dq no . | ||
1691 | .It Cm TunnelDevice | 1544 | .It Cm TunnelDevice |
1692 | Specifies the | 1545 | Specifies the |
1693 | .Xr tun 4 | 1546 | .Xr tun 4 |
@@ -1701,14 +1554,14 @@ The argument must be | |||
1701 | .Ar local_tun Op : Ar remote_tun . | 1554 | .Ar local_tun Op : Ar remote_tun . |
1702 | .Sm on | 1555 | .Sm on |
1703 | The devices may be specified by numerical ID or the keyword | 1556 | The devices may be specified by numerical ID or the keyword |
1704 | .Dq any , | 1557 | .Cm any , |
1705 | which uses the next available tunnel device. | 1558 | which uses the next available tunnel device. |
1706 | If | 1559 | If |
1707 | .Ar remote_tun | 1560 | .Ar remote_tun |
1708 | is not specified, it defaults to | 1561 | is not specified, it defaults to |
1709 | .Dq any . | 1562 | .Cm any . |
1710 | The default is | 1563 | The default is |
1711 | .Dq any:any . | 1564 | .Cm any:any . |
1712 | .It Cm UpdateHostKeys | 1565 | .It Cm UpdateHostKeys |
1713 | Specifies whether | 1566 | Specifies whether |
1714 | .Xr ssh 1 | 1567 | .Xr ssh 1 |
@@ -1716,10 +1569,10 @@ should accept notifications of additional hostkeys from the server sent | |||
1716 | after authentication has completed and add them to | 1569 | after authentication has completed and add them to |
1717 | .Cm UserKnownHostsFile . | 1570 | .Cm UserKnownHostsFile . |
1718 | The argument must be | 1571 | The argument must be |
1719 | .Dq yes , | 1572 | .Cm yes , |
1720 | .Dq no | 1573 | .Cm no |
1721 | (the default) or | 1574 | (the default) or |
1722 | .Dq ask . | 1575 | .Cm ask . |
1723 | Enabling this option allows learning alternate hostkeys for a server | 1576 | Enabling this option allows learning alternate hostkeys for a server |
1724 | and supports graceful key rotation by allowing a server to send replacement | 1577 | and supports graceful key rotation by allowing a server to send replacement |
1725 | public keys before old ones are removed. | 1578 | public keys before old ones are removed. |
@@ -1728,7 +1581,7 @@ host was already trusted or explicitly accepted by the user. | |||
1728 | If | 1581 | If |
1729 | .Cm UpdateHostKeys | 1582 | .Cm UpdateHostKeys |
1730 | is set to | 1583 | is set to |
1731 | .Dq ask , | 1584 | .Cm ask , |
1732 | then the user is asked to confirm the modifications to the known_hosts file. | 1585 | then the user is asked to confirm the modifications to the known_hosts file. |
1733 | Confirmation is currently incompatible with | 1586 | Confirmation is currently incompatible with |
1734 | .Cm ControlPersist , | 1587 | .Cm ControlPersist , |
@@ -1737,22 +1590,21 @@ and will be disabled if it is enabled. | |||
1737 | Presently, only | 1590 | Presently, only |
1738 | .Xr sshd 8 | 1591 | .Xr sshd 8 |
1739 | from OpenSSH 6.8 and greater support the | 1592 | from OpenSSH 6.8 and greater support the |
1740 | .Dq hostkeys@openssh.com | 1593 | .Qq hostkeys@openssh.com |
1741 | protocol extension used to inform the client of all the server's hostkeys. | 1594 | protocol extension used to inform the client of all the server's hostkeys. |
1742 | .It Cm UsePrivilegedPort | 1595 | .It Cm UsePrivilegedPort |
1743 | Specifies whether to use a privileged port for outgoing connections. | 1596 | Specifies whether to use a privileged port for outgoing connections. |
1744 | The argument must be | 1597 | The argument must be |
1745 | .Dq yes | 1598 | .Cm yes |
1746 | or | 1599 | or |
1747 | .Dq no . | 1600 | .Cm no |
1748 | The default is | 1601 | (the default). |
1749 | .Dq no . | ||
1750 | If set to | 1602 | If set to |
1751 | .Dq yes , | 1603 | .Cm yes , |
1752 | .Xr ssh 1 | 1604 | .Xr ssh 1 |
1753 | must be setuid root. | 1605 | must be setuid root. |
1754 | Note that this option must be set to | 1606 | Note that this option must be set to |
1755 | .Dq yes | 1607 | .Cm yes |
1756 | for | 1608 | for |
1757 | .Cm RhostsRSAAuthentication | 1609 | .Cm RhostsRSAAuthentication |
1758 | with older servers. | 1610 | with older servers. |
@@ -1771,39 +1623,35 @@ The default is | |||
1771 | Specifies whether to verify the remote key using DNS and SSHFP resource | 1623 | Specifies whether to verify the remote key using DNS and SSHFP resource |
1772 | records. | 1624 | records. |
1773 | If this option is set to | 1625 | If this option is set to |
1774 | .Dq yes , | 1626 | .Cm yes , |
1775 | the client will implicitly trust keys that match a secure fingerprint | 1627 | the client will implicitly trust keys that match a secure fingerprint |
1776 | from DNS. | 1628 | from DNS. |
1777 | Insecure fingerprints will be handled as if this option was set to | 1629 | Insecure fingerprints will be handled as if this option was set to |
1778 | .Dq ask . | 1630 | .Cm ask . |
1779 | If this option is set to | 1631 | If this option is set to |
1780 | .Dq ask , | 1632 | .Cm ask , |
1781 | information on fingerprint match will be displayed, but the user will still | 1633 | information on fingerprint match will be displayed, but the user will still |
1782 | need to confirm new host keys according to the | 1634 | need to confirm new host keys according to the |
1783 | .Cm StrictHostKeyChecking | 1635 | .Cm StrictHostKeyChecking |
1784 | option. | 1636 | option. |
1785 | The argument must be | ||
1786 | .Dq yes , | ||
1787 | .Dq no , | ||
1788 | or | ||
1789 | .Dq ask . | ||
1790 | The default is | 1637 | The default is |
1791 | .Dq no . | 1638 | .Cm no . |
1792 | .Pp | 1639 | .Pp |
1793 | See also VERIFYING HOST KEYS in | 1640 | See also |
1641 | .Sx VERIFYING HOST KEYS | ||
1642 | in | ||
1794 | .Xr ssh 1 . | 1643 | .Xr ssh 1 . |
1795 | .It Cm VisualHostKey | 1644 | .It Cm VisualHostKey |
1796 | If this flag is set to | 1645 | If this flag is set to |
1797 | .Dq yes , | 1646 | .Cm yes , |
1798 | an ASCII art representation of the remote host key fingerprint is | 1647 | an ASCII art representation of the remote host key fingerprint is |
1799 | printed in addition to the fingerprint string at login and | 1648 | printed in addition to the fingerprint string at login and |
1800 | for unknown host keys. | 1649 | for unknown host keys. |
1801 | If this flag is set to | 1650 | If this flag is set to |
1802 | .Dq no , | 1651 | .Cm no |
1652 | (the default), | ||
1803 | no fingerprint strings are printed at login and | 1653 | no fingerprint strings are printed at login and |
1804 | only the fingerprint string will be printed for unknown host keys. | 1654 | only the fingerprint string will be printed for unknown host keys. |
1805 | The default is | ||
1806 | .Dq no . | ||
1807 | .It Cm XAuthLocation | 1655 | .It Cm XAuthLocation |
1808 | Specifies the full pathname of the | 1656 | Specifies the full pathname of the |
1809 | .Xr xauth 1 | 1657 | .Xr xauth 1 |
@@ -1821,7 +1669,7 @@ or | |||
1821 | .Sq ?\& | 1669 | .Sq ?\& |
1822 | (a wildcard that matches exactly one character). | 1670 | (a wildcard that matches exactly one character). |
1823 | For example, to specify a set of declarations for any host in the | 1671 | For example, to specify a set of declarations for any host in the |
1824 | .Dq .co.uk | 1672 | .Qq .co.uk |
1825 | set of domains, | 1673 | set of domains, |
1826 | the following pattern could be used: | 1674 | the following pattern could be used: |
1827 | .Pp | 1675 | .Pp |
@@ -1841,11 +1689,63 @@ by preceding them with an exclamation mark | |||
1841 | For example, | 1689 | For example, |
1842 | to allow a key to be used from anywhere within an organization | 1690 | to allow a key to be used from anywhere within an organization |
1843 | except from the | 1691 | except from the |
1844 | .Dq dialup | 1692 | .Qq dialup |
1845 | pool, | 1693 | pool, |
1846 | the following entry (in authorized_keys) could be used: | 1694 | the following entry (in authorized_keys) could be used: |
1847 | .Pp | 1695 | .Pp |
1848 | .Dl from=\&"!*.dialup.example.com,*.example.com\&" | 1696 | .Dl from=\&"!*.dialup.example.com,*.example.com\&" |
1697 | .Sh TOKENS | ||
1698 | Arguments to some keywords can make use of tokens, | ||
1699 | which are expanded at runtime: | ||
1700 | .Pp | ||
1701 | .Bl -tag -width XXXX -offset indent -compact | ||
1702 | .It %% | ||
1703 | A literal | ||
1704 | .Sq % . | ||
1705 | .It \&%C | ||
1706 | Shorthand for %l%h%p%r. | ||
1707 | .It %d | ||
1708 | Local user's home directory. | ||
1709 | .It %h | ||
1710 | The remote hostname. | ||
1711 | .It %i | ||
1712 | The local user ID. | ||
1713 | .It %L | ||
1714 | The local hostname. | ||
1715 | .It %l | ||
1716 | The local hostname, including the domain name. | ||
1717 | .It %n | ||
1718 | The original remote hostname, as given on the command line. | ||
1719 | .It %p | ||
1720 | The remote port. | ||
1721 | .It %r | ||
1722 | The remote username. | ||
1723 | .It %u | ||
1724 | The local username. | ||
1725 | .El | ||
1726 | .Pp | ||
1727 | .Cm Match exec | ||
1728 | accepts the tokens %%, %h, %L, %l, %n, %p, %r, and %u. | ||
1729 | .Pp | ||
1730 | .Cm CertificateFile | ||
1731 | accepts the tokens %%, %d, %h, %l, %r, and %u. | ||
1732 | .Pp | ||
1733 | .Cm ControlPath | ||
1734 | accepts the tokens %%, %C, %h, %i, %L, %l, %n, %p, %r, and %u. | ||
1735 | .Pp | ||
1736 | .Cm HostName | ||
1737 | accepts the tokens %% and %h. | ||
1738 | .Pp | ||
1739 | .Cm IdentityAgent | ||
1740 | and | ||
1741 | .Cm IdentityFile | ||
1742 | accept the tokens %%, %d, %h, %l, %r, and %u. | ||
1743 | .Pp | ||
1744 | .Cm LocalCommand | ||
1745 | accepts the tokens %%, %C, %d, %h, %l, %n, %p, %r, and %u. | ||
1746 | .Pp | ||
1747 | .Cm ProxyCommand | ||
1748 | accepts the tokens %%, %h, %p, and %r. | ||
1849 | .Sh FILES | 1749 | .Sh FILES |
1850 | .Bl -tag -width Ds | 1750 | .Bl -tag -width Ds |
1851 | .It Pa ~/.ssh/config | 1751 | .It Pa ~/.ssh/config |
@@ -1864,11 +1764,15 @@ This file must be world-readable. | |||
1864 | .Sh SEE ALSO | 1764 | .Sh SEE ALSO |
1865 | .Xr ssh 1 | 1765 | .Xr ssh 1 |
1866 | .Sh AUTHORS | 1766 | .Sh AUTHORS |
1767 | .An -nosplit | ||
1867 | OpenSSH is a derivative of the original and free | 1768 | OpenSSH is a derivative of the original and free |
1868 | ssh 1.2.12 release by Tatu Ylonen. | 1769 | ssh 1.2.12 release by |
1869 | Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, | 1770 | .An Tatu Ylonen . |
1870 | Theo de Raadt and Dug Song | 1771 | .An Aaron Campbell , Bob Beck , Markus Friedl , |
1772 | .An Niels Provos , Theo de Raadt | ||
1773 | and | ||
1774 | .An Dug Song | ||
1871 | removed many bugs, re-added newer features and | 1775 | removed many bugs, re-added newer features and |
1872 | created OpenSSH. | 1776 | created OpenSSH. |
1873 | Markus Friedl contributed the support for SSH | 1777 | .An Markus Friedl |
1874 | protocol versions 1.5 and 2.0. | 1778 | contributed the support for SSH protocol versions 1.5 and 2.0. |