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1223864Shselasky<html lang="en"> 2223864Shselasky<head> 3223864Shselasky<title>Ntp-keygen User's Manual</title> 4223864Shselasky<meta http-equiv="Content-Type" content="text/html"> 5223864Shselasky<meta name="description" content="Ntp-keygen User's Manual"> 6223864Shselasky<meta name="generator" content="makeinfo 4.7"> 7223864Shselasky<link title="Top" rel="top" href="#Top"> 8223864Shselasky<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 9223864Shselasky<meta http-equiv="Content-Style-Type" content="text/css"> 10223864Shselasky<style type="text/css"><!-- 11223864Shselasky pre.display { font-family:inherit } 12223864Shselasky pre.format { font-family:inherit } 13223864Shselasky pre.smalldisplay { font-family:inherit; font-size:smaller } 14223864Shselasky pre.smallformat { font-family:inherit; font-size:smaller } 15223864Shselasky pre.smallexample { font-size:smaller } 16223864Shselasky pre.smalllisp { font-size:smaller } 17223864Shselasky span.sc { font-variant:small-caps } 18223864Shselasky span.roman { font-family: serif; font-weight: normal; } 19223864Shselasky--></style> 20223864Shselasky</head> 21223864Shselasky<body> 22223864Shselasky<h1 class="settitle">Ntp-keygen User's Manual</h1> 23223864Shselasky <div class="shortcontents"> 24223864Shselasky<h2>Short Contents</h2> 25223864Shselasky<ul> 26223864Shselasky<a href="#Top">Top</a> 27223864Shselasky<a href="#Top">NTP Key Generation Program User Manual</a> 28223864Shselasky</ul> 29223864Shselasky</div> 30223864Shselasky 31223864Shselasky 32223864Shselasky 33223864Shselasky<div class="node"> 34223864Shselasky<p><hr> 35223864Shselasky<a name="Top"></a>Up: <a rel="up" accesskey="u" href="#dir">(dir)</a> 36223864Shselasky<br> 37223864Shselasky</div> 38223864Shselasky 39223864Shselasky<h2 class="unnumbered">Top</h2> 40223864Shselasky 41223864Shselasky<ul class="menu"> 42223864Shselasky<li><a accesskey="1" href="#Description">Description</a> 43223864Shselasky<li><a accesskey="2" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a>: Invoking ntp-keygen 44223864Shselasky<li><a accesskey="3" href="#Running-the-Program">Running the Program</a> 45223864Shselasky<li><a accesskey="4" href="#Random-Seed-File">Random Seed File</a> 46223864Shselasky<li><a accesskey="5" href="#Cryptographic-Data-Files">Cryptographic Data Files</a> 47223864Shselasky</ul> 48223864Shselasky 49223864Shselasky<div class="node"> 50223864Shselasky<p><hr> 51223864Shselasky<a name="Top"></a>Next: <a rel="next" accesskey="n" href="#Description">Description</a>, 52223864ShselaskyPrevious: <a rel="previous" accesskey="p" href="#dir">(dir)</a>, 53223864ShselaskyUp: <a rel="up" accesskey="u" href="#dir">(dir)</a> 54223864Shselasky<br> 55223864Shselasky</div> 56223864Shselasky 57223864Shselasky<h2 class="unnumbered">NTP Key Generation Program User Manual</h2> 58223864Shselasky 59223864Shselasky<p>This document describes the use of the NTP Project's <code>ntp-keygen</code> 60223864Shselaskyprogram, that generates cryptographic data files used by the NTPv4 61223864Shselaskyauthentication and identity schemes. 62223864ShselaskyIt can generate message digest keys used in symmetric key cryptography and, 63223864Shselaskyif the OpenSSL software 64223864Shselaskylibrary has been installed, it can generate host keys, sign keys, 65223864Shselaskycertificates, and identity keys and parameters used by the Autokey 66223864Shselaskypublic key cryptography. 67223864ShselaskyThe message digest keys file is generated in a 68223864Shselaskyformat compatible with NTPv3. 69223864ShselaskyAll other files are in PEM-encoded 70223864Shselaskyprintable ASCII format so they can be embedded as MIME attachments in 71223864Shselaskymail to other sites. 72223864Shselasky 73223864Shselasky <p>This document applies to version 4.2.8p7 of <code>ntp-keygen</code>. 74223864Shselasky 75223864Shselasky<div class="node"> 76223864Shselasky<p><hr> 77223864Shselasky<a name="Description"></a>Next: <a rel="next" accesskey="n" href="#Running-the-Program">Running the Program</a>, 78223864ShselaskyPrevious: <a rel="previous" accesskey="p" href="#Top">Top</a>, 79223864ShselaskyUp: <a rel="up" accesskey="u" href="#Top">Top</a> 80223864Shselasky<br> 81223864Shselasky</div> 82223864Shselasky 83223864Shselasky<!-- node-name, next, previous, up --> 84223864Shselasky<h3 class="section">Description</h3> 85223864Shselasky 86223864Shselasky<p>This program generates cryptographic data files used by the NTPv4 87223864Shselaskyauthentication and identity schemes. It can generate message digest 88223864Shselaskykeys used in symmetric key cryptography and, if the OpenSSL software 89223864Shselaskylibrary has been installed, it can generate host keys, sign keys, 90223864Shselaskycertificates, and identity keys and parameters used by the Autokey 91223864Shselaskypublic key cryptography. The message digest keys file is generated in a 92223864Shselaskyformat compatible with NTPv3. All other files are in PEM-encoded 93223864Shselaskyprintable ASCII format so they can be embedded as MIME attachments in 94223864Shselaskymail to other sites. 95223864Shselasky 96223864Shselasky <p>When used to generate message digest keys, the program produces a file 97223864Shselaskycontaining ten pseudo-random printable ASCII strings suitable for the 98223864ShselaskyMD5 message digest algorithm included in the distribution. 99223864ShselaskyIf the 100223864ShselaskyOpenSSL library is installed, it produces an additional ten hex-encoded 101223864Shselaskyrandom bit strings suitable for the SHA1 and other message digest 102223864Shselaskyalgorithms. 103223864ShselaskyThe message digest keys file must be distributed and stored 104223864Shselaskyusing secure means beyond the scope of NTP itself. 105223864ShselaskyBesides the keys 106223864Shselaskyused for ordinary NTP associations, additional keys can be defined as 107223864Shselaskypasswords for the ntpq and ntpdc utility programs. 108223864Shselasky 109223864Shselasky <p>The remaining generated files are compatible with other OpenSSL 110223864Shselaskyapplications and other Public Key Infrastructure (PKI) resources. 111223864ShselaskyCertificates generated by this program are compatible with extant 112223864Shselaskyindustry practice, although some users might find the interpretation of 113223864ShselaskyX509v3 extension fields somewhat liberal. 114223864ShselaskyHowever, the identity keys 115223864Shselaskyare probably not compatible with anything other than Autokey. 116223864Shselasky 117223864Shselasky <p>Some files used by this program are encrypted using a private password. 118223864ShselaskyThe <code>-p</code> option specifies the password for local encrypted files and the 119223864Shselasky<code>-q</code> option the password for encrypted files sent to remote sites. 120223864ShselaskyIf no password is specified, the host name returned by the Unix 121223864Shselasky<code>gethostname()</code> function, normally the DNS name of the host, is used. 122223864Shselasky 123223864Shselasky <p>The <kbd>pw</kbd> option of the <code>crypto</code> configuration command 124223864Shselaskyspecifies the read password for previously encrypted local files. 125223864ShselaskyThis must match the local password used by this program. 126223864ShselaskyIf not specified, the host name is used. 127223864ShselaskyThus, if files are generated by this program without password, 128223864Shselaskythey can be read back by ntpd without password, but only on the same 129223864Shselaskyhost. 130223864Shselasky 131223864Shselasky <p>Normally, encrypted files for each host are generated by that host and 132223864Shselaskyused only by that host, although exceptions exist as noted later on 133223864Shselaskythis page. 134223864ShselaskyThe symmetric keys file, normally called <code>ntp.keys</code>, is 135223864Shselaskyusually installed in <code>/etc</code>. 136223864ShselaskyOther files and links are usually installed 137223864Shselaskyin <code>/usr/local/etc</code>, which is normally in a shared filesystem in 138223864ShselaskyNFS-mounted networks and cannot be changed by shared clients. 139223864ShselaskyThe location of the keys directory can be changed by the keysdir 140223864Shselaskyconfiguration command in such cases. 141223864ShselaskyNormally, this is in <code>/etc</code>. 142223864Shselasky 143223864Shselasky <p>This program directs commentary and error messages to the standard 144223864Shselaskyerror stream <code>stderr</code> and remote files to the standard output stream 145223864Shselasky<code>stdout</code> where they can be piped to other applications or redirected to 146223864Shselaskyfiles. 147223864ShselaskyThe names used for generated files and links all begin with the 148223864Shselaskystring <code>ntpkey</code> and include the file type, 149223864Shselaskygenerating host and filestamp, 150223864Shselaskyas described in the <a href="#Cryptographic-Data-Files">Cryptographic Data Files</a> section below. 151223864Shselasky 152223864Shselasky<div class="node"> 153223864Shselasky<p><hr> 154223864Shselasky<a name="Running-the-Program"></a>Next: <a rel="next" accesskey="n" href="#Random-Seed-File">Random Seed File</a>, 155223864ShselaskyPrevious: <a rel="previous" accesskey="p" href="#Description">Description</a>, 156223864ShselaskyUp: <a rel="up" accesskey="u" href="#Top">Top</a> 157223864Shselasky<br> 158223864Shselasky</div> 159223864Shselasky 160223864Shselasky<!-- node-name, next, previous, up --> 161223864Shselasky<h3 class="section">Running the Program</h3> 162223864Shselasky 163223864Shselasky<p>To test and gain experience with Autokey concepts, log in as root and 164223864Shselaskychange to the keys directory, usually <code>/usr/local/etc</code>. 165223864ShselaskyWhen run for the 166223864Shselaskyfirst time, or if all files with names beginning <code>ntpkey</code>] have been 167223864Shselaskyremoved, use the <code>ntp-keygen</code> command without arguments to generate a 168223864Shselaskydefault RSA host key and matching RSA-MD5 certificate with expiration 169223864Shselaskydate one year hence. 170223864ShselaskyIf run again without options, the program uses the 171223864Shselaskyexisting keys and parameters and generates only a new certificate with 172223864Shselaskynew expiration date one year hence. 173223864Shselasky 174223864Shselasky <p>Run the command on as many hosts as necessary. 175223864ShselaskyDesignate one of them as the trusted host (TH) using <code>ntp-keygen</code> 176223864Shselaskywith the <code>-T</code> option and configure 177223864Shselaskyit to synchronize from reliable Internet servers. 178223864ShselaskyThen configure the other hosts to synchronize to the TH directly or indirectly. 179223864ShselaskyA certificate trail is created when Autokey asks the immediately 180223864Shselaskyascendant host towards the TH to sign its certificate, which is then 181223864Shselaskyprovided to the immediately descendant host on request. 182223864ShselaskyAll group hosts should have acyclic certificate trails ending on the TH. 183223864Shselasky 184223864Shselasky <p>The host key is used to encrypt the cookie when required and so must be 185223864ShselaskyRSA type. 186223864ShselaskyBy default, the host key is also the sign key used to encrypt signatures. 187223864ShselaskyA different sign key can be assigned using the <code>-S</code> option 188223864Shselaskyand this can be either RSA or DSA type. 189223864ShselaskyBy default, the signature 190223864Shselaskymessage digest type is MD5, but any combination of sign key type and 191223864Shselaskymessage digest type supported by the OpenSSL library can be specified 192223864Shselaskyusing the <code>-c</code> option. 193223864Shselasky 194223864Shselasky <p>The rules say cryptographic media should be generated with proventic 195223864Shselaskyfilestamps, which means the host should already be synchronized before 196223864Shselaskythis program is run. 197223864ShselaskyThis of course creates a chicken-and-egg problem 198223864Shselaskywhen the host is started for the first time. 199223864ShselaskyAccordingly, the host time 200223864Shselaskyshould be set by some other means, such as eyeball-and-wristwatch, at 201223864Shselaskyleast so that the certificate lifetime is within the current year. 202223864ShselaskyAfter that and when the host is synchronized to a proventic source, the 203223864Shselaskycertificate should be re-generated. 204223864Shselasky 205223864Shselasky <p>Additional information on trusted groups and identity schemes is on the 206223864ShselaskyAutokey Public-Key Authentication page. 207223864Shselasky 208223864Shselasky<div class="node"> 209223864Shselasky<p><hr> 210223864Shselasky<a name="ntp_002dkeygen-Invocation"></a> 211223864Shselasky<br> 212223864Shselasky</div> 213223864Shselasky 214223864Shselasky<h3 class="section">Invoking ntp-keygen</h3> 215223864Shselasky 216223864Shselasky<p><a name="index-ntp_002dkeygen-1"></a><a name="index-Create-a-NTP-host-key-2"></a> 217223864Shselasky 218223864Shselasky <p>This program generates cryptographic data files used by the NTPv4 219223864Shselaskyauthentication and identification schemes. 220223864ShselaskyIt generates MD5 key files used in symmetric key cryptography. 221223864ShselaskyIn addition, if the OpenSSL software library has been installed, 222223864Shselaskyit generates keys, certificate and identity files used in public key 223223864Shselaskycryptography. 224223864ShselaskyThese files are used for cookie encryption, 225223864Shselaskydigital signature and challenge/response identification algorithms 226223864Shselaskycompatible with the Internet standard security infrastructure. 227223864Shselasky 228223864Shselasky <p>All files are in PEM-encoded printable ASCII format, 229223864Shselaskyso they can be embedded as MIME attachments in mail to other sites 230223864Shselaskyand certificate authorities. 231223864ShselaskyBy default, files are not encrypted. 232223864Shselasky 233223864Shselasky <p>When used to generate message digest keys, the program produces a file 234223864Shselaskycontaining ten pseudo-random printable ASCII strings suitable for the 235223864ShselaskyMD5 message digest algorithm included in the distribution. 236223864ShselaskyIf the OpenSSL library is installed, it produces an additional ten 237223864Shselaskyhex-encoded random bit strings suitable for the SHA1 and other message 238223864Shselaskydigest algorithms. 239223864ShselaskyThe message digest keys file must be distributed and stored 240223864Shselaskyusing secure means beyond the scope of NTP itself. 241223864ShselaskyBesides the keys used for ordinary NTP associations, additional keys 242223864Shselaskycan be defined as passwords for the 243223864Shselasky<code>ntpq(1ntpqmdoc)</code> 244223864Shselaskyand 245223864Shselasky<code>ntpdc(1ntpdcmdoc)</code> 246223864Shselaskyutility programs. 247223864Shselasky 248223864Shselasky <p>The remaining generated files are compatible with other OpenSSL 249223864Shselaskyapplications and other Public Key Infrastructure (PKI) resources. 250223864ShselaskyCertificates generated by this program are compatible with extant 251223864Shselaskyindustry practice, although some users might find the interpretation of 252223864ShselaskyX509v3 extension fields somewhat liberal. 253223864ShselaskyHowever, the identity keys are probably not compatible with anything 254223864Shselaskyother than Autokey. 255223864Shselasky 256223864Shselasky <p>Some files used by this program are encrypted using a private password. 257The 258<code>-p</code> 259option specifies the password for local encrypted files and the 260<code>-q</code> 261option the password for encrypted files sent to remote sites. 262If no password is specified, the host name returned by the Unix 263<code>gethostname()</code> 264function, normally the DNS name of the host is used. 265 266 <p>The 267<kbd>pw</kbd> 268option of the 269<kbd>crypto</kbd> 270configuration command specifies the read 271password for previously encrypted local files. 272This must match the local password used by this program. 273If not specified, the host name is used. 274Thus, if files are generated by this program without password, 275they can be read back by 276<kbd>ntpd</kbd> 277without password but only on the same host. 278 279 <p>Normally, encrypted files for each host are generated by that host and 280used only by that host, although exceptions exist as noted later on 281this page. 282The symmetric keys file, normally called 283<kbd>ntp.keys</kbd>, 284is usually installed in 285<span class="file">/etc</span>. 286Other files and links are usually installed in 287<span class="file">/usr/local/etc</span>, 288which is normally in a shared filesystem in 289NFS-mounted networks and cannot be changed by shared clients. 290The location of the keys directory can be changed by the 291<kbd>keysdir</kbd> 292configuration command in such cases. 293Normally, this is in 294<span class="file">/etc</span>. 295 296 <p>This program directs commentary and error messages to the standard 297error stream 298<kbd>stderr</kbd> 299and remote files to the standard output stream 300<kbd>stdout</kbd> 301where they can be piped to other applications or redirected to files. 302The names used for generated files and links all begin with the 303string 304<kbd>ntpkey</kbd> 305and include the file type, generating host and filestamp, 306as described in the 307Cryptographic Data Files 308section below. 309 310<h5 class="subsubsection">Running the Program</h5> 311 312<p>To test and gain experience with Autokey concepts, log in as root and 313change to the keys directory, usually 314<span class="file">/usr/local/etc</span> 315When run for the first time, or if all files with names beginning with 316<kbd>ntpkey</kbd> 317have been removed, use the 318<code>ntp-keygen</code> 319command without arguments to generate a 320default RSA host key and matching RSA-MD5 certificate with expiration 321date one year hence. 322If run again without options, the program uses the 323existing keys and parameters and generates only a new certificate with 324new expiration date one year hence. 325 326 <p>Run the command on as many hosts as necessary. 327Designate one of them as the trusted host (TH) using 328<code>ntp-keygen</code> 329with the 330<code>-T</code> 331option and configure it to synchronize from reliable Internet servers. 332Then configure the other hosts to synchronize to the TH directly or 333indirectly. 334A certificate trail is created when Autokey asks the immediately 335ascendant host towards the TH to sign its certificate, which is then 336provided to the immediately descendant host on request. 337All group hosts should have acyclic certificate trails ending on the TH. 338 339 <p>The host key is used to encrypt the cookie when required and so must be 340RSA type. 341By default, the host key is also the sign key used to encrypt 342signatures. 343A different sign key can be assigned using the 344<code>-S</code> 345option and this can be either RSA or DSA type. 346By default, the signature 347message digest type is MD5, but any combination of sign key type and 348message digest type supported by the OpenSSL library can be specified 349using the 350<code>-c</code> 351option. 352The rules say cryptographic media should be generated with proventic 353filestamps, which means the host should already be synchronized before 354this program is run. 355This of course creates a chicken-and-egg problem 356when the host is started for the first time. 357Accordingly, the host time 358should be set by some other means, such as eyeball-and-wristwatch, at 359least so that the certificate lifetime is within the current year. 360After that and when the host is synchronized to a proventic source, the 361certificate should be re-generated. 362 363 <p>Additional information on trusted groups and identity schemes is on the 364Autokey Public-Key Authentication 365page. 366 367 <p>The 368<code>ntpd(1ntpdmdoc)</code> 369configuration command 370<code>crypto</code> <code>pw</code> <kbd>password</kbd> 371specifies the read password for previously encrypted files. 372The daemon expires on the spot if the password is missing 373or incorrect. 374For convenience, if a file has been previously encrypted, 375the default read password is the name of the host running 376the program. 377If the previous write password is specified as the host name, 378these files can be read by that host with no explicit password. 379 380 <p>File names begin with the prefix 381<code>ntpkey_</code> 382and end with the postfix 383<kbd>_hostname.filestamp</kbd>, 384where 385<kbd>hostname</kbd> 386is the owner name, usually the string returned 387by the Unix gethostname() routine, and 388<kbd>filestamp</kbd> 389is the NTP seconds when the file was generated, in decimal digits. 390This both guarantees uniqueness and simplifies maintenance 391procedures, since all files can be quickly removed 392by a 393<code>rm</code> <code>ntpkey*</code> 394command or all files generated 395at a specific time can be removed by a 396<code>rm</code> 397<kbd>*filestamp</kbd> 398command. 399To further reduce the risk of misconfiguration, 400the first two lines of a file contain the file name 401and generation date and time as comments. 402 403 <p>All files are installed by default in the keys directory 404<span class="file">/usr/local/etc</span>, 405which is normally in a shared filesystem 406in NFS-mounted networks. 407The actual location of the keys directory 408and each file can be overridden by configuration commands, 409but this is not recommended. 410Normally, the files for each host are generated by that host 411and used only by that host, although exceptions exist 412as noted later on this page. 413 414 <p>Normally, files containing private values, 415including the host key, sign key and identification parameters, 416are permitted root read/write-only; 417while others containing public values are permitted world readable. 418Alternatively, files containing private values can be encrypted 419and these files permitted world readable, 420which simplifies maintenance in shared file systems. 421Since uniqueness is insured by the hostname and 422file name extensions, the files for a NFS server and 423dependent clients can all be installed in the same shared directory. 424 425 <p>The recommended practice is to keep the file name extensions 426when installing a file and to install a soft link 427from the generic names specified elsewhere on this page 428to the generated files. 429This allows new file generations to be activated simply 430by changing the link. 431If a link is present, ntpd follows it to the file name 432to extract the filestamp. 433If a link is not present, 434<code>ntpd(1ntpdmdoc)</code> 435extracts the filestamp from the file itself. 436This allows clients to verify that the file and generation times 437are always current. 438The 439<code>ntp-keygen</code> 440program uses the same timestamp extension for all files generated 441at one time, so each generation is distinct and can be readily 442recognized in monitoring data. 443 444<h5 class="subsubsection">Running the program</h5> 445 446<p>The safest way to run the 447<code>ntp-keygen</code> 448program is logged in directly as root. 449The recommended procedure is change to the keys directory, 450usually 451<span class="file">/usr/local/etc</span>, 452then run the program. 453When run for the first time, 454or if all 455<code>ntpkey</code> 456files have been removed, 457the program generates a RSA host key file and matching RSA-MD5 certificate file, 458which is all that is necessary in many cases. 459The program also generates soft links from the generic names 460to the respective files. 461If run again, the program uses the same host key file, 462but generates a new certificate file and link. 463 464 <p>The host key is used to encrypt the cookie when required and so must be RSA type. 465By default, the host key is also the sign key used to encrypt signatures. 466When necessary, a different sign key can be specified and this can be 467either RSA or DSA type. 468By default, the message digest type is MD5, but any combination 469of sign key type and message digest type supported by the OpenSSL library 470can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2 471and RIPE160 message digest algorithms. 472However, the scheme specified in the certificate must be compatible 473with the sign key. 474Certificates using any digest algorithm are compatible with RSA sign keys; 475however, only SHA and SHA1 certificates are compatible with DSA sign keys. 476 477 <p>Private/public key files and certificates are compatible with 478other OpenSSL applications and very likely other libraries as well. 479Certificates or certificate requests derived from them should be compatible 480with extant industry practice, although some users might find 481the interpretation of X509v3 extension fields somewhat liberal. 482However, the identification parameter files, although encoded 483as the other files, are probably not compatible with anything other than Autokey. 484 485 <p>Running the program as other than root and using the Unix 486<code>su</code> 487command 488to assume root may not work properly, since by default the OpenSSL library 489looks for the random seed file 490<code>.rnd</code> 491in the user home directory. 492However, there should be only one 493<code>.rnd</code>, 494most conveniently 495in the root directory, so it is convenient to define the 496<code>$RANDFILE</code> 497environment variable used by the OpenSSL library as the path to 498<code>/.rnd</code>. 499 500 <p>Installing the keys as root might not work in NFS-mounted 501shared file systems, as NFS clients may not be able to write 502to the shared keys directory, even as root. 503In this case, NFS clients can specify the files in another 504directory such as 505<span class="file">/etc</span> 506using the 507<code>keysdir</code> 508command. 509There is no need for one client to read the keys and certificates 510of other clients or servers, as these data are obtained automatically 511by the Autokey protocol. 512 513 <p>Ordinarily, cryptographic files are generated by the host that uses them, 514but it is possible for a trusted agent (TA) to generate these files 515for other hosts; however, in such cases files should always be encrypted. 516The subject name and trusted name default to the hostname 517of the host generating the files, but can be changed by command line options. 518It is convenient to designate the owner name and trusted name 519as the subject and issuer fields, respectively, of the certificate. 520The owner name is also used for the host and sign key files, 521while the trusted name is used for the identity files. 522 523 <p>All files are installed by default in the keys directory 524<span class="file">/usr/local/etc</span>, 525which is normally in a shared filesystem 526in NFS-mounted networks. 527The actual location of the keys directory 528and each file can be overridden by configuration commands, 529but this is not recommended. 530Normally, the files for each host are generated by that host 531and used only by that host, although exceptions exist 532as noted later on this page. 533 534 <p>Normally, files containing private values, 535including the host key, sign key and identification parameters, 536are permitted root read/write-only; 537while others containing public values are permitted world readable. 538Alternatively, files containing private values can be encrypted 539and these files permitted world readable, 540which simplifies maintenance in shared file systems. 541Since uniqueness is insured by the hostname and 542file name extensions, the files for a NFS server and 543dependent clients can all be installed in the same shared directory. 544 545 <p>The recommended practice is to keep the file name extensions 546when installing a file and to install a soft link 547from the generic names specified elsewhere on this page 548to the generated files. 549This allows new file generations to be activated simply 550by changing the link. 551If a link is present, ntpd follows it to the file name 552to extract the filestamp. 553If a link is not present, 554<code>ntpd(1ntpdmdoc)</code> 555extracts the filestamp from the file itself. 556This allows clients to verify that the file and generation times 557are always current. 558The 559<code>ntp-keygen</code> 560program uses the same timestamp extension for all files generated 561at one time, so each generation is distinct and can be readily 562recognized in monitoring data. 563 564<h5 class="subsubsection">Running the program</h5> 565 566<p>The safest way to run the 567<code>ntp-keygen</code> 568program is logged in directly as root. 569The recommended procedure is change to the keys directory, 570usually 571<span class="file">/usr/local/etc</span>, 572then run the program. 573When run for the first time, 574or if all 575<code>ntpkey</code> 576files have been removed, 577the program generates a RSA host key file and matching RSA-MD5 certificate file, 578which is all that is necessary in many cases. 579The program also generates soft links from the generic names 580to the respective files. 581If run again, the program uses the same host key file, 582but generates a new certificate file and link. 583 584 <p>The host key is used to encrypt the cookie when required and so must be RSA type. 585By default, the host key is also the sign key used to encrypt signatures. 586When necessary, a different sign key can be specified and this can be 587either RSA or DSA type. 588By default, the message digest type is MD5, but any combination 589of sign key type and message digest type supported by the OpenSSL library 590can be specified, including those using the MD2, MD5, SHA, SHA1, MDC2 591and RIPE160 message digest algorithms. 592However, the scheme specified in the certificate must be compatible 593with the sign key. 594Certificates using any digest algorithm are compatible with RSA sign keys; 595however, only SHA and SHA1 certificates are compatible with DSA sign keys. 596 597 <p>Private/public key files and certificates are compatible with 598other OpenSSL applications and very likely other libraries as well. 599Certificates or certificate requests derived from them should be compatible 600with extant industry practice, although some users might find 601the interpretation of X509v3 extension fields somewhat liberal. 602However, the identification parameter files, although encoded 603as the other files, are probably not compatible with anything other than Autokey. 604 605 <p>Running the program as other than root and using the Unix 606<code>su</code> 607command 608to assume root may not work properly, since by default the OpenSSL library 609looks for the random seed file 610<code>.rnd</code> 611in the user home directory. 612However, there should be only one 613<code>.rnd</code>, 614most conveniently 615in the root directory, so it is convenient to define the 616<code>$RANDFILE</code> 617environment variable used by the OpenSSL library as the path to 618<code>/.rnd</code>. 619 620 <p>Installing the keys as root might not work in NFS-mounted 621shared file systems, as NFS clients may not be able to write 622to the shared keys directory, even as root. 623In this case, NFS clients can specify the files in another 624directory such as 625<span class="file">/etc</span> 626using the 627<code>keysdir</code> 628command. 629There is no need for one client to read the keys and certificates 630of other clients or servers, as these data are obtained automatically 631by the Autokey protocol. 632 633 <p>Ordinarily, cryptographic files are generated by the host that uses them, 634but it is possible for a trusted agent (TA) to generate these files 635for other hosts; however, in such cases files should always be encrypted. 636The subject name and trusted name default to the hostname 637of the host generating the files, but can be changed by command line options. 638It is convenient to designate the owner name and trusted name 639as the subject and issuer fields, respectively, of the certificate. 640The owner name is also used for the host and sign key files, 641while the trusted name is used for the identity files. 642seconds. 643seconds. 644 645 <p>s Trusted Hosts and Groups 646Each cryptographic configuration involves selection of a signature scheme 647and identification scheme, called a cryptotype, 648as explained in the 649<a href="#Authentication-Options">Authentication Options</a> 650section of 651<code>ntp.conf(5)</code>. 652The default cryptotype uses RSA encryption, MD5 message digest 653and TC identification. 654First, configure a NTP subnet including one or more low-stratum 655trusted hosts from which all other hosts derive synchronization 656directly or indirectly. 657Trusted hosts have trusted certificates; 658all other hosts have nontrusted certificates. 659These hosts will automatically and dynamically build authoritative 660certificate trails to one or more trusted hosts. 661A trusted group is the set of all hosts that have, directly or indirectly, 662a certificate trail ending at a trusted host. 663The trail is defined by static configuration file entries 664or dynamic means described on the 665<a href="#Automatic-NTP-Configuration-Options">Automatic NTP Configuration Options</a> 666section of 667<code>ntp.conf(5)</code>. 668 669 <p>On each trusted host as root, change to the keys directory. 670To insure a fresh fileset, remove all 671<code>ntpkey</code> 672files. 673Then run 674<code>ntp-keygen</code> 675<code>-T</code> 676to generate keys and a trusted certificate. 677On all other hosts do the same, but leave off the 678<code>-T</code> 679flag to generate keys and nontrusted certificates. 680When complete, start the NTP daemons beginning at the lowest stratum 681and working up the tree. 682It may take some time for Autokey to instantiate the certificate trails 683throughout the subnet, but setting up the environment is completely automatic. 684 685 <p>If it is necessary to use a different sign key or different digest/signature 686scheme than the default, run 687<code>ntp-keygen</code> 688with the 689<code>-S</code> <kbd>type</kbd> 690option, where 691<kbd>type</kbd> 692is either 693<code>RSA</code> 694or 695<code>DSA</code>. 696The most often need to do this is when a DSA-signed certificate is used. 697If it is necessary to use a different certificate scheme than the default, 698run 699<code>ntp-keygen</code> 700with the 701<code>-c</code> <kbd>scheme</kbd> 702option and selected 703<kbd>scheme</kbd> 704as needed. 705f 706<code>ntp-keygen</code> 707is run again without these options, it generates a new certificate 708using the same scheme and sign key. 709 710 <p>After setting up the environment it is advisable to update certificates 711from time to time, if only to extend the validity interval. 712Simply run 713<code>ntp-keygen</code> 714with the same flags as before to generate new certificates 715using existing keys. 716However, if the host or sign key is changed, 717<code>ntpd(1ntpdmdoc)</code> 718should be restarted. 719When 720<code>ntpd(1ntpdmdoc)</code> 721is restarted, it loads any new files and restarts the protocol. 722Other dependent hosts will continue as usual until signatures are refreshed, 723at which time the protocol is restarted. 724 725<h5 class="subsubsection">Identity Schemes</h5> 726 727<p>As mentioned on the Autonomous Authentication page, 728the default TC identity scheme is vulnerable to a middleman attack. 729However, there are more secure identity schemes available, 730including PC, IFF, GQ and MV described on the 731"Identification Schemes" 732page 733(maybe available at 734<code>http://www.eecis.udel.edu/%7emills/keygen.html</code>). 735These schemes are based on a TA, one or more trusted hosts 736and some number of nontrusted hosts. 737Trusted hosts prove identity using values provided by the TA, 738while the remaining hosts prove identity using values provided 739by a trusted host and certificate trails that end on that host. 740The name of a trusted host is also the name of its sugroup 741and also the subject and issuer name on its trusted certificate. 742The TA is not necessarily a trusted host in this sense, but often is. 743 744 <p>In some schemes there are separate keys for servers and clients. 745A server can also be a client of another server, 746but a client can never be a server for another client. 747In general, trusted hosts and nontrusted hosts that operate 748as both server and client have parameter files that contain 749both server and client keys. 750Hosts that operate 751only as clients have key files that contain only client keys. 752 753 <p>The PC scheme supports only one trusted host in the group. 754On trusted host alice run 755<code>ntp-keygen</code> 756<code>-P</code> 757<code>-p</code> <kbd>password</kbd> 758to generate the host key file 759<span class="file">ntpkey_RSAkey_</span><kbd>alice.filestamp</kbd> 760and trusted private certificate file 761<span class="file">ntpkey_RSA-MD5_cert_</span><kbd>alice.filestamp</kbd>. 762Copy both files to all group hosts; 763they replace the files which would be generated in other schemes. 764On each host bob install a soft link from the generic name 765<span class="file">ntpkey_host_</span><kbd>bob</kbd> 766to the host key file and soft link 767<span class="file">ntpkey_cert_</span><kbd>bob</kbd> 768to the private certificate file. 769Note the generic links are on bob, but point to files generated 770by trusted host alice. 771In this scheme it is not possible to refresh 772either the keys or certificates without copying them 773to all other hosts in the group. 774 775 <p>For the IFF scheme proceed as in the TC scheme to generate keys 776and certificates for all group hosts, then for every trusted host in the group, 777generate the IFF parameter file. 778On trusted host alice run 779<code>ntp-keygen</code> 780<code>-T</code> 781<code>-I</code> 782<code>-p</code> <kbd>password</kbd> 783to produce her parameter file 784<span class="file">ntpkey_IFFpar_</span><kbd>alice.filestamp</kbd>, 785which includes both server and client keys. 786Copy this file to all group hosts that operate as both servers 787and clients and install a soft link from the generic 788<span class="file">ntpkey_iff_</span><kbd>alice</kbd> 789to this file. 790If there are no hosts restricted to operate only as clients, 791there is nothing further to do. 792As the IFF scheme is independent 793of keys and certificates, these files can be refreshed as needed. 794 795 <p>If a rogue client has the parameter file, it could masquerade 796as a legitimate server and present a middleman threat. 797To eliminate this threat, the client keys can be extracted 798from the parameter file and distributed to all restricted clients. 799After generating the parameter file, on alice run 800<code>ntp-keygen</code> 801<code>-e</code> 802and pipe the output to a file or mail program. 803Copy or mail this file to all restricted clients. 804On these clients install a soft link from the generic 805<span class="file">ntpkey_iff_</span><kbd>alice</kbd> 806to this file. 807To further protect the integrity of the keys, 808each file can be encrypted with a secret password. 809 810 <p>For the GQ scheme proceed as in the TC scheme to generate keys 811and certificates for all group hosts, then for every trusted host 812in the group, generate the IFF parameter file. 813On trusted host alice run 814<code>ntp-keygen</code> 815<code>-T</code> 816<code>-G</code> 817<code>-p</code> <kbd>password</kbd> 818to produce her parameter file 819<span class="file">ntpkey_GQpar_</span><kbd>alice.filestamp</kbd>, 820which includes both server and client keys. 821Copy this file to all group hosts and install a soft link 822from the generic 823<span class="file">ntpkey_gq_</span><kbd>alice</kbd> 824to this file. 825In addition, on each host bob install a soft link 826from generic 827<span class="file">ntpkey_gq_</span><kbd>bob</kbd> 828to this file. 829As the GQ scheme updates the GQ parameters file and certificate 830at the same time, keys and certificates can be regenerated as needed. 831 832 <p>For the MV scheme, proceed as in the TC scheme to generate keys 833and certificates for all group hosts. 834For illustration assume trish is the TA, alice one of several trusted hosts 835and bob one of her clients. 836On TA trish run 837<code>ntp-keygen</code> 838<code>-V</code> <kbd>n</kbd> 839<code>-p</code> <kbd>password</kbd>, 840where 841<kbd>n</kbd> 842is the number of revokable keys (typically 5) to produce 843the parameter file 844<span class="file">ntpkeys_MVpar_</span><kbd>trish.filestamp</kbd> 845and client key files 846<span class="file">ntpkeys_MVkeyd_</span><kbd>trish.filestamp</kbd> 847where 848<kbd>d</kbd> 849is the key number (0 < 850<kbd>d</kbd> 851< 852<kbd>n</kbd>). 853Copy the parameter file to alice and install a soft link 854from the generic 855<span class="file">ntpkey_mv_</span><kbd>alice</kbd> 856to this file. 857Copy one of the client key files to alice for later distribution 858to her clients. 859It doesn't matter which client key file goes to alice, 860since they all work the same way. 861Alice copies the client key file to all of her cliens. 862On client bob install a soft link from generic 863<span class="file">ntpkey_mvkey_</span><kbd>bob</kbd> 864to the client key file. 865As the MV scheme is independent of keys and certificates, 866these files can be refreshed as needed. 867 868<h5 class="subsubsection">Command Line Options</h5> 869 870 <dl> 871<dt><code>-c</code> <kbd>scheme</kbd><dd>Select certificate message digest/signature encryption scheme. 872The 873<kbd>scheme</kbd> 874can be one of the following: 875. Cm RSA-MD2 , RSA-MD5 , RSA-SHA , RSA-SHA1 , RSA-MDC2 , RSA-RIPEMD160 , DSA-SHA , 876or 877<code>DSA-SHA1</code>. 878Note that RSA schemes must be used with a RSA sign key and DSA 879schemes must be used with a DSA sign key. 880The default without this option is 881<code>RSA-MD5</code>. 882<br><dt><code>-d</code><dd>Enable debugging. 883This option displays the cryptographic data produced in eye-friendly billboards. 884<br><dt><code>-e</code><dd>Write the IFF client keys to the standard output. 885This is intended for automatic key distribution by mail. 886<br><dt><code>-G</code><dd>Generate parameters and keys for the GQ identification scheme, 887obsoleting any that may exist. 888<br><dt><code>-g</code><dd>Generate keys for the GQ identification scheme 889using the existing GQ parameters. 890If the GQ parameters do not yet exist, create them first. 891<br><dt><code>-H</code><dd>Generate new host keys, obsoleting any that may exist. 892<br><dt><code>-I</code><dd>Generate parameters for the IFF identification scheme, 893obsoleting any that may exist. 894<br><dt><code>-i</code> <kbd>name</kbd><dd>Set the suject name to 895<kbd>name</kbd>. 896This is used as the subject field in certificates 897and in the file name for host and sign keys. 898<br><dt><code>-M</code><dd>Generate MD5 keys, obsoleting any that may exist. 899<br><dt><code>-P</code><dd>Generate a private certificate. 900By default, the program generates public certificates. 901<br><dt><code>-p</code> <kbd>password</kbd><dd>Encrypt generated files containing private data with 902<kbd>password</kbd> 903and the DES-CBC algorithm. 904<br><dt><code>-q</code><dd>Set the password for reading files to password. 905<br><dt><code>-S</code> <code>[RSA | DSA]</code><dd>Generate a new sign key of the designated type, 906obsoleting any that may exist. 907By default, the program uses the host key as the sign key. 908<br><dt><code>-s</code> <kbd>name</kbd><dd>Set the issuer name to 909<kbd>name</kbd>. 910This is used for the issuer field in certificates 911and in the file name for identity files. 912<br><dt><code>-T</code><dd>Generate a trusted certificate. 913By default, the program generates a non-trusted certificate. 914<br><dt><code>-V</code> <kbd>nkeys</kbd><dd>Generate parameters and keys for the Mu-Varadharajan (MV) identification scheme. 915</dl> 916 917<h5 class="subsubsection">Random Seed File</h5> 918 919<p>All cryptographically sound key generation schemes must have means 920to randomize the entropy seed used to initialize 921the internal pseudo-random number generator used 922by the library routines. 923The OpenSSL library uses a designated random seed file for this purpose. 924The file must be available when starting the NTP daemon and 925<code>ntp-keygen</code> 926program. 927If a site supports OpenSSL or its companion OpenSSH, 928it is very likely that means to do this are already available. 929 930 <p>It is important to understand that entropy must be evolved 931for each generation, for otherwise the random number sequence 932would be predictable. 933Various means dependent on external events, such as keystroke intervals, 934can be used to do this and some systems have built-in entropy sources. 935Suitable means are described in the OpenSSL software documentation, 936but are outside the scope of this page. 937 938 <p>The entropy seed used by the OpenSSL library is contained in a file, 939usually called 940<code>.rnd</code>, 941which must be available when starting the NTP daemon 942or the 943<code>ntp-keygen</code> 944program. 945The NTP daemon will first look for the file 946using the path specified by the 947<code>randfile</code> 948subcommand of the 949<code>crypto</code> 950configuration command. 951If not specified in this way, or when starting the 952<code>ntp-keygen</code> 953program, 954the OpenSSL library will look for the file using the path specified 955by the 956.Ev RANDFILE 957environment variable in the user home directory, 958whether root or some other user. 959If the 960.Ev RANDFILE 961environment variable is not present, 962the library will look for the 963<code>.rnd</code> 964file in the user home directory. 965If the file is not available or cannot be written, 966the daemon exits with a message to the system log and the program 967exits with a suitable error message. 968 969<h5 class="subsubsection">Cryptographic Data Files</h5> 970 971<p>All other file formats begin with two lines. 972The first contains the file name, including the generated host name 973and filestamp. 974The second contains the datestamp in conventional Unix date format. 975Lines beginning with # are considered comments and ignored by the 976<code>ntp-keygen</code> 977program and 978<code>ntpd(1ntpdmdoc)</code> 979daemon. 980Cryptographic values are encoded first using ASN.1 rules, 981then encrypted if necessary, and finally written PEM-encoded 982printable ASCII format preceded and followed by MIME content identifier lines. 983 984 <p>The format of the symmetric keys file is somewhat different 985than the other files in the interest of backward compatibility. 986Since DES-CBC is deprecated in NTPv4, the only key format of interest 987is MD5 alphanumeric strings. 988Following hte heard the keys are 989entered one per line in the format 990<pre class="example"> <kbd>keyno</kbd> <kbd>type</kbd> <kbd>key</kbd> 991</pre> 992 <p>where 993<kbd>keyno</kbd> 994is a positive integer in the range 1-65,535, 995<kbd>type</kbd> 996is the string MD5 defining the key format and 997<kbd>key</kbd> 998is the key itself, 999which is a printable ASCII string 16 characters or less in length. 1000Each character is chosen from the 93 printable characters 1001in the range 0x21 through 0x7f excluding space and the 1002# 1003character. 1004 1005 <p>Note that the keys used by the 1006<code>ntpq(1ntpqmdoc)</code> 1007and 1008<code>ntpdc(1ntpdcmdoc)</code> 1009programs 1010are checked against passwords requested by the programs 1011and entered by hand, so it is generally appropriate to specify these keys 1012in human readable ASCII format. 1013 1014 <p>The 1015<code>ntp-keygen</code> 1016program generates a MD5 symmetric keys file 1017<span class="file">ntpkey_MD5key_</span><kbd>hostname.filestamp</kbd>. 1018Since the file contains private shared keys, 1019it should be visible only to root and distributed by secure means 1020to other subnet hosts. 1021The NTP daemon loads the file 1022<span class="file">ntp.keys</span>, 1023so 1024<code>ntp-keygen</code> 1025installs a soft link from this name to the generated file. 1026Subsequently, similar soft links must be installed by manual 1027or automated means on the other subnet hosts. 1028While this file is not used with the Autokey Version 2 protocol, 1029it is needed to authenticate some remote configuration commands 1030used by the 1031<code>ntpq(1ntpqmdoc)</code> 1032and 1033<code>ntpdc(1ntpdcmdoc)</code> 1034utilities. 1035 1036 <p>This section was generated by <strong>AutoGen</strong>, 1037using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntp-keygen</code> program. 1038This software is released under the NTP license, <http://ntp.org/license>;. 1039 1040<ul class="menu"> 1041<li><a accesskey="1" href="#ntp_002dkeygen-usage">ntp-keygen usage</a>: ntp-keygen help/usage (<span class="option">--help</span>) 1042<li><a accesskey="2" href="#ntp_002dkeygen-imbits">ntp-keygen imbits</a>: imbits option (-b) 1043<li><a accesskey="3" href="#ntp_002dkeygen-certificate">ntp-keygen certificate</a>: certificate option (-c) 1044<li><a accesskey="4" href="#ntp_002dkeygen-cipher">ntp-keygen cipher</a>: cipher option (-C) 1045<li><a accesskey="5" href="#ntp_002dkeygen-id_002dkey">ntp-keygen id-key</a>: id-key option (-e) 1046<li><a accesskey="6" href="#ntp_002dkeygen-gq_002dparams">ntp-keygen gq-params</a>: gq-params option (-G) 1047<li><a accesskey="7" href="#ntp_002dkeygen-host_002dkey">ntp-keygen host-key</a>: host-key option (-H) 1048<li><a accesskey="8" href="#ntp_002dkeygen-iffkey">ntp-keygen iffkey</a>: iffkey option (-I) 1049<li><a accesskey="9" href="#ntp_002dkeygen-ident">ntp-keygen ident</a>: ident option (-i) 1050<li><a href="#ntp_002dkeygen-lifetime">ntp-keygen lifetime</a>: lifetime option (-l) 1051<li><a href="#ntp_002dkeygen-md5key">ntp-keygen md5key</a>: md5key option (-M) 1052<li><a href="#ntp_002dkeygen-modulus">ntp-keygen modulus</a>: modulus option (-m) 1053<li><a href="#ntp_002dkeygen-pvt_002dcert">ntp-keygen pvt-cert</a>: pvt-cert option (-P) 1054<li><a href="#ntp_002dkeygen-password">ntp-keygen password</a>: password option (-p) 1055<li><a href="#ntp_002dkeygen-export_002dpasswd">ntp-keygen export-passwd</a>: export-passwd option (-q) 1056<li><a href="#ntp_002dkeygen-sign_002dkey">ntp-keygen sign-key</a>: sign-key option (-S) 1057<li><a href="#ntp_002dkeygen-subject_002dname">ntp-keygen subject-name</a>: subject-name option (-s) 1058<li><a href="#ntp_002dkeygen-trusted_002dcert">ntp-keygen trusted-cert</a>: trusted-cert option (-T) 1059<li><a href="#ntp_002dkeygen-mv_002dparams">ntp-keygen mv-params</a>: mv-params option (-V) 1060<li><a href="#ntp_002dkeygen-mv_002dkeys">ntp-keygen mv-keys</a>: mv-keys option (-v) 1061<li><a href="#ntp_002dkeygen-config">ntp-keygen config</a>: presetting/configuring ntp-keygen 1062<li><a href="#ntp_002dkeygen-exit-status">ntp-keygen exit status</a>: exit status 1063<li><a href="#ntp_002dkeygen-Usage">ntp-keygen Usage</a>: Usage 1064<li><a href="#ntp_002dkeygen-Notes">ntp-keygen Notes</a>: Notes 1065<li><a href="#ntp_002dkeygen-Bugs">ntp-keygen Bugs</a>: Bugs 1066</ul> 1067 1068<div class="node"> 1069<p><hr> 1070<a name="ntp_002dkeygen-usage"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-imbits">ntp-keygen imbits</a>, 1071Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1072<br> 1073</div> 1074 1075<h4 class="subsection">ntp-keygen help/usage (<span class="option">--help</span>)</h4> 1076 1077<p><a name="index-ntp_002dkeygen-help-3"></a> 1078This is the automatically generated usage text for ntp-keygen. 1079 1080 <p>The text printed is the same whether selected with the <code>help</code> option 1081(<span class="option">--help</span>) or the <code>more-help</code> option (<span class="option">--more-help</span>). <code>more-help</code> will print 1082the usage text by passing it through a pager program. 1083<code>more-help</code> is disabled on platforms without a working 1084<code>fork(2)</code> function. The <code>PAGER</code> environment variable is 1085used to select the program, defaulting to <span class="file">more</span>. Both will exit 1086with a status code of 0. 1087 1088<pre class="example">ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.8p6 1089Usage: ntp-keygen [ -<flag> [<val>] | --<name>[{=| }<val>] ]... 1090 Flg Arg Option-Name Description 1091 -b Num imbits identity modulus bits 1092 - it must be in the range: 1093 256 to 2048 1094 -c Str certificate certificate scheme 1095 -C Str cipher privatekey cipher 1096 -d no debug-level Increase debug verbosity level 1097 - may appear multiple times 1098 -D Num set-debug-level Set the debug verbosity level 1099 - may appear multiple times 1100 -e no id-key Write IFF or GQ identity keys 1101 -G no gq-params Generate GQ parameters and keys 1102 -H no host-key generate RSA host key 1103 -I no iffkey generate IFF parameters 1104 -i Str ident set Autokey group name 1105 -l Num lifetime set certificate lifetime 1106 -M no md5key generate MD5 keys 1107 -m Num modulus modulus 1108 - it must be in the range: 1109 256 to 2048 1110 -P no pvt-cert generate PC private certificate 1111 -p Str password local private password 1112 -q Str export-passwd export IFF or GQ group keys with password 1113 -S Str sign-key generate sign key (RSA or DSA) 1114 -s Str subject-name set host and optionally group name 1115 -T no trusted-cert trusted certificate (TC scheme) 1116 -V Num mv-params generate <num> MV parameters 1117 -v Num mv-keys update <num> MV keys 1118 opt version output version information and exit 1119 -? no help display extended usage information and exit 1120 -! no more-help extended usage information passed thru pager 1121 -> opt save-opts save the option state to a config file 1122 -< Str load-opts load options from a config file 1123 - disabled as '--no-load-opts' 1124 - may appear multiple times 1125 1126Options are specified by doubled hyphens and their name or by a single 1127hyphen and the flag character. 1128 1129 1130The following option preset mechanisms are supported: 1131 - reading file $HOME/.ntprc 1132 - reading file ./.ntprc 1133 - examining environment variables named NTP_KEYGEN_* 1134 1135Please send bug reports to: <http://bugs.ntp.org, bugs@ntp.org> 1136</pre> 1137 <div class="node"> 1138<p><hr> 1139<a name="ntp_002dkeygen-imbits"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-certificate">ntp-keygen certificate</a>, 1140Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-usage">ntp-keygen usage</a>, 1141Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1142<br> 1143</div> 1144 1145<h4 class="subsection">imbits option (-b)</h4> 1146 1147<p><a name="index-ntp_002dkeygen_002dimbits-4"></a> 1148This is the “identity modulus bits” option. 1149This option takes a number argument <span class="file">imbits</span>. 1150 1151<p class="noindent">This option has some usage constraints. It: 1152 <ul> 1153<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1154</ul> 1155 1156 <p>The number of bits in the identity modulus. The default is 256. 1157<div class="node"> 1158<p><hr> 1159<a name="ntp_002dkeygen-certificate"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-cipher">ntp-keygen cipher</a>, 1160Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-imbits">ntp-keygen imbits</a>, 1161Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1162<br> 1163</div> 1164 1165<h4 class="subsection">certificate option (-c)</h4> 1166 1167<p><a name="index-ntp_002dkeygen_002dcertificate-5"></a> 1168This is the “certificate scheme” option. 1169This option takes a string argument <span class="file">scheme</span>. 1170 1171<p class="noindent">This option has some usage constraints. It: 1172 <ul> 1173<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1174</ul> 1175 1176 <p>scheme is one of 1177RSA-MD2, RSA-MD5, RSA-SHA, RSA-SHA1, RSA-MDC2, RSA-RIPEMD160, 1178DSA-SHA, or DSA-SHA1. 1179 1180 <p>Select the certificate message digest/signature encryption scheme. 1181Note that RSA schemes must be used with a RSA sign key and DSA 1182schemes must be used with a DSA sign key. The default without 1183this option is RSA-MD5. 1184<div class="node"> 1185<p><hr> 1186<a name="ntp_002dkeygen-cipher"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-id_002dkey">ntp-keygen id-key</a>, 1187Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-certificate">ntp-keygen certificate</a>, 1188Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1189<br> 1190</div> 1191 1192<h4 class="subsection">cipher option (-C)</h4> 1193 1194<p><a name="index-ntp_002dkeygen_002dcipher-6"></a> 1195This is the “privatekey cipher” option. 1196This option takes a string argument <span class="file">cipher</span>. 1197 1198<p class="noindent">This option has some usage constraints. It: 1199 <ul> 1200<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1201</ul> 1202 1203 <p>Select the cipher which is used to encrypt the files containing 1204private keys. The default is three-key triple DES in CBC mode, 1205equivalent to "<code>-C des-ede3-cbc". The openssl tool lists ciphers 1206available in "openssl -h" output. 1207</code><div class="node"> 1208<p><hr> 1209<a name="ntp_002dkeygen-id_002dkey"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-gq_002dparams">ntp-keygen gq-params</a>, 1210Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-cipher">ntp-keygen cipher</a>, 1211Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1212<br> 1213</div> 1214 1215<h4 class="subsection">id-key option (-e)</h4> 1216 1217<p><a name="index-ntp_002dkeygen_002did_002dkey-7"></a> 1218This is the “write iff or gq identity keys” option. 1219 1220<p class="noindent">This option has some usage constraints. It: 1221 <ul> 1222<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1223</ul> 1224 1225 <p>Write the IFF or GQ client keys to the standard output. This is 1226intended for automatic key distribution by mail. 1227<div class="node"> 1228<p><hr> 1229<a name="ntp_002dkeygen-gq_002dparams"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-host_002dkey">ntp-keygen host-key</a>, 1230Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-id_002dkey">ntp-keygen id-key</a>, 1231Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1232<br> 1233</div> 1234 1235<h4 class="subsection">gq-params option (-G)</h4> 1236 1237<p><a name="index-ntp_002dkeygen_002dgq_002dparams-8"></a> 1238This is the “generate gq parameters and keys” option. 1239 1240<p class="noindent">This option has some usage constraints. It: 1241 <ul> 1242<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1243</ul> 1244 1245 <p>Generate parameters and keys for the GQ identification scheme, 1246obsoleting any that may exist. 1247<div class="node"> 1248<p><hr> 1249<a name="ntp_002dkeygen-host_002dkey"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-iffkey">ntp-keygen iffkey</a>, 1250Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-gq_002dparams">ntp-keygen gq-params</a>, 1251Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1252<br> 1253</div> 1254 1255<h4 class="subsection">host-key option (-H)</h4> 1256 1257<p><a name="index-ntp_002dkeygen_002dhost_002dkey-9"></a> 1258This is the “generate rsa host key” option. 1259 1260<p class="noindent">This option has some usage constraints. It: 1261 <ul> 1262<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1263</ul> 1264 1265 <p>Generate new host keys, obsoleting any that may exist. 1266<div class="node"> 1267<p><hr> 1268<a name="ntp_002dkeygen-iffkey"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-ident">ntp-keygen ident</a>, 1269Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-host_002dkey">ntp-keygen host-key</a>, 1270Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1271<br> 1272</div> 1273 1274<h4 class="subsection">iffkey option (-I)</h4> 1275 1276<p><a name="index-ntp_002dkeygen_002diffkey-10"></a> 1277This is the “generate iff parameters” option. 1278 1279<p class="noindent">This option has some usage constraints. It: 1280 <ul> 1281<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1282</ul> 1283 1284 <p>Generate parameters for the IFF identification scheme, obsoleting 1285any that may exist. 1286<div class="node"> 1287<p><hr> 1288<a name="ntp_002dkeygen-ident"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-lifetime">ntp-keygen lifetime</a>, 1289Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-iffkey">ntp-keygen iffkey</a>, 1290Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1291<br> 1292</div> 1293 1294<h4 class="subsection">ident option (-i)</h4> 1295 1296<p><a name="index-ntp_002dkeygen_002dident-11"></a> 1297This is the “set autokey group name” option. 1298This option takes a string argument <span class="file">group</span>. 1299 1300<p class="noindent">This option has some usage constraints. It: 1301 <ul> 1302<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1303</ul> 1304 1305 <p>Set the optional Autokey group name to name. This is used in 1306the file name of IFF, GQ, and MV client parameters files. In 1307that role, the default is the host name if this option is not 1308provided. The group name, if specified using <code>-i/--ident</code> or 1309using <code>-s/--subject-name</code> following an '<code>}' character, 1310is also a part of the self-signed host certificate's subject and 1311issuer names in the form host 1312 <p>'crypto ident' or 'server ident' configuration in 1313ntpd's configuration file. 1314</code><div class="node"> 1315<p><hr> 1316<a name="ntp_002dkeygen-lifetime"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-md5key">ntp-keygen md5key</a>, 1317Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-ident">ntp-keygen ident</a>, 1318Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1319<br> 1320</div> 1321 1322<h4 class="subsection">lifetime option (-l)</h4> 1323 1324<p><a name="index-ntp_002dkeygen_002dlifetime-12"></a> 1325This is the ``set certificate lifetime'' option. 1326This option takes a number argument <span class="file">lifetime</span>. 1327 1328<p class="noindent">This option has some usage constraints. It: 1329 <ul> 1330<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1331</ul> 1332 1333 <p>Set the certificate expiration to lifetime days from now. 1334<div class="node"> 1335<p><hr> 1336<a name="ntp_002dkeygen-md5key"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-modulus">ntp-keygen modulus</a>, 1337Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-lifetime">ntp-keygen lifetime</a>, 1338Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1339<br> 1340</div> 1341 1342<h4 class="subsection">md5key option (-M)</h4> 1343 1344<p><a name="index-ntp_002dkeygen_002dmd5key-13"></a> 1345This is the ``generate md5 keys'' option. 1346Generate MD5 keys, obsoleting any that may exist. 1347<div class="node"> 1348<p><hr> 1349<a name="ntp_002dkeygen-modulus"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-pvt_002dcert">ntp-keygen pvt-cert</a>, 1350Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-md5key">ntp-keygen md5key</a>, 1351Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1352<br> 1353</div> 1354 1355<h4 class="subsection">modulus option (-m)</h4> 1356 1357<p><a name="index-ntp_002dkeygen_002dmodulus-14"></a> 1358This is the ``modulus'' option. 1359This option takes a number argument <span class="file">modulus</span>. 1360 1361<p class="noindent">This option has some usage constraints. It: 1362 <ul> 1363<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1364</ul> 1365 1366 <p>The number of bits in the prime modulus. The default is 512. 1367<div class="node"> 1368<p><hr> 1369<a name="ntp_002dkeygen-pvt_002dcert"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-password">ntp-keygen password</a>, 1370Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-modulus">ntp-keygen modulus</a>, 1371Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1372<br> 1373</div> 1374 1375<h4 class="subsection">pvt-cert option (-P)</h4> 1376 1377<p><a name="index-ntp_002dkeygen_002dpvt_002dcert-15"></a> 1378This is the ``generate pc private certificate'' option. 1379 1380<p class="noindent">This option has some usage constraints. It: 1381 <ul> 1382<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1383</ul> 1384 1385 <p>Generate a private certificate. By default, the program generates 1386public certificates. 1387<div class="node"> 1388<p><hr> 1389<a name="ntp_002dkeygen-password"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-export_002dpasswd">ntp-keygen export-passwd</a>, 1390Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-pvt_002dcert">ntp-keygen pvt-cert</a>, 1391Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1392<br> 1393</div> 1394 1395<h4 class="subsection">password option (-p)</h4> 1396 1397<p><a name="index-ntp_002dkeygen_002dpassword-16"></a> 1398This is the ``local private password'' option. 1399This option takes a string argument <span class="file">passwd</span>. 1400 1401<p class="noindent">This option has some usage constraints. It: 1402 <ul> 1403<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1404</ul> 1405 1406 <p>Local files containing private data are encrypted with the 1407DES-CBC algorithm and the specified password. The same password 1408must be specified to the local ntpd via the "crypto pw password" 1409configuration command. The default password is the local 1410hostname. 1411<div class="node"> 1412<p><hr> 1413<a name="ntp_002dkeygen-export_002dpasswd"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-sign_002dkey">ntp-keygen sign-key</a>, 1414Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-password">ntp-keygen password</a>, 1415Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1416<br> 1417</div> 1418 1419<h4 class="subsection">export-passwd option (-q)</h4> 1420 1421<p><a name="index-ntp_002dkeygen_002dexport_002dpasswd-17"></a> 1422This is the ``export iff or gq group keys with password'' option. 1423This option takes a string argument <span class="file">passwd</span>. 1424 1425<p class="noindent">This option has some usage constraints. It: 1426 <ul> 1427<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1428</ul> 1429 1430 <p>Export IFF or GQ identity group keys to the standard output, 1431encrypted with the DES-CBC algorithm and the specified password. 1432The same password must be specified to the remote ntpd via the 1433"crypto pw password" configuration command. See also the option 1434--id-key (-e) for unencrypted exports. 1435<div class="node"> 1436<p><hr> 1437<a name="ntp_002dkeygen-sign_002dkey"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-subject_002dname">ntp-keygen subject-name</a>, 1438Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-export_002dpasswd">ntp-keygen export-passwd</a>, 1439Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1440<br> 1441</div> 1442 1443<h4 class="subsection">sign-key option (-S)</h4> 1444 1445<p><a name="index-ntp_002dkeygen_002dsign_002dkey-18"></a> 1446This is the ``generate sign key (rsa or dsa)'' option. 1447This option takes a string argument <span class="file">sign</span>. 1448 1449<p class="noindent">This option has some usage constraints. It: 1450 <ul> 1451<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1452</ul> 1453 1454 <p>Generate a new sign key of the designated type, obsoleting any 1455that may exist. By default, the program uses the host key as the 1456sign key. 1457<div class="node"> 1458<p><hr> 1459<a name="ntp_002dkeygen-subject_002dname"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-trusted_002dcert">ntp-keygen trusted-cert</a>, 1460Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-sign_002dkey">ntp-keygen sign-key</a>, 1461Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1462<br> 1463</div> 1464 1465<h4 class="subsection">subject-name option (-s)</h4> 1466 1467<p><a name="index-ntp_002dkeygen_002dsubject_002dname-19"></a> 1468This is the ``set host and optionally group name'' option. 1469This option takes a string argument <span class="file">host@group</span>. 1470 1471<p class="noindent">This option has some usage constraints. It: 1472 <ul> 1473<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1474</ul> 1475 1476 <p>Set the Autokey host name, and optionally, group name specified 1477following an '<code>}' character. The host name is used in the file 1478name of generated host and signing certificates, without the 1479group name. The host name, and if provided, group name are used 1480in host 1481 <p>fields. Specifying '-s 1482 <p>leaving the host name unchanged while appending 1483 <p>subject and issuer fields, as with -i group. The group name, or 1484if not provided, the host name are also used in the file names 1485of IFF, GQ, and MV client parameter files. 1486</code><div class="node"> 1487<p><hr> 1488<a name="ntp_002dkeygen-trusted_002dcert"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-mv_002dparams">ntp-keygen mv-params</a>, 1489Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-subject_002dname">ntp-keygen subject-name</a>, 1490Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1491<br> 1492</div> 1493 1494<h4 class="subsection">trusted-cert option (-T)</h4> 1495 1496<p><a name="index-ntp_002dkeygen_002dtrusted_002dcert-20"></a> 1497This is the ``trusted certificate (tc scheme)'' option. 1498 1499<p class="noindent">This option has some usage constraints. It: 1500 <ul> 1501<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1502</ul> 1503 1504 <p>Generate a trusted certificate. By default, the program generates 1505a non-trusted certificate. 1506<div class="node"> 1507<p><hr> 1508<a name="ntp_002dkeygen-mv_002dparams"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-mv_002dkeys">ntp-keygen mv-keys</a>, 1509Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-trusted_002dcert">ntp-keygen trusted-cert</a>, 1510Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1511<br> 1512</div> 1513 1514<h4 class="subsection">mv-params option (-V)</h4> 1515 1516<p><a name="index-ntp_002dkeygen_002dmv_002dparams-21"></a> 1517This is the ``generate <num> mv parameters'' option. 1518This option takes a number argument <span class="file">num</span>. 1519 1520<p class="noindent">This option has some usage constraints. It: 1521 <ul> 1522<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1523</ul> 1524 1525 <p>Generate parameters and keys for the Mu-Varadharajan (MV) 1526identification scheme. 1527<div class="node"> 1528<p><hr> 1529<a name="ntp_002dkeygen-mv_002dkeys"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-config">ntp-keygen config</a>, 1530Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-mv_002dparams">ntp-keygen mv-params</a>, 1531Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1532<br> 1533</div> 1534 1535<h4 class="subsection">mv-keys option (-v)</h4> 1536 1537<p><a name="index-ntp_002dkeygen_002dmv_002dkeys-22"></a> 1538This is the ``update <num> mv keys'' option. 1539This option takes a number argument <span class="file">num</span>. 1540 1541<p class="noindent">This option has some usage constraints. It: 1542 <ul> 1543<li>must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1544</ul> 1545 1546 <p>This option has no <span class="samp">doc</span> documentation. 1547 1548<div class="node"> 1549<p><hr> 1550<a name="ntp_002dkeygen-config"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-exit-status">ntp-keygen exit status</a>, 1551Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-mv_002dkeys">ntp-keygen mv-keys</a>, 1552Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1553<br> 1554</div> 1555 1556<h4 class="subsection">presetting/configuring ntp-keygen</h4> 1557 1558<p>Any option that is not marked as <i>not presettable</i> may be preset by 1559loading values from configuration ("rc" or "ini") files, and values from environment variables named <code>NTP-KEYGEN</code> and <code>NTP-KEYGEN_<OPTION_NAME></code>. <code><OPTION_NAME></code> must be one of 1560the options listed above in upper case and segmented with underscores. 1561The <code>NTP-KEYGEN</code> variable will be tokenized and parsed like 1562the command line. The remaining variables are tested for existence and their 1563values are treated like option arguments. 1564 1565<p class="noindent"><code>libopts</code> will search in 2 places for configuration files: 1566 <ul> 1567<li>$HOME 1568<li>$PWD 1569</ul> 1570 The environment variables <code>HOME</code>, and <code>PWD</code> 1571are expanded and replaced when <span class="file">ntp-keygen</span> runs. 1572For any of these that are plain files, they are simply processed. 1573For any that are directories, then a file named <span class="file">.ntprc</span> is searched for 1574within that directory and processed. 1575 1576 <p>Configuration files may be in a wide variety of formats. 1577The basic format is an option name followed by a value (argument) on the 1578same line. Values may be separated from the option name with a colon, 1579equal sign or simply white space. Values may be continued across multiple 1580lines by escaping the newline with a backslash. 1581 1582 <p>Multiple programs may also share the same initialization file. 1583Common options are collected at the top, followed by program specific 1584segments. The segments are separated by lines like: 1585<pre class="example"> [NTP-KEYGEN] 1586</pre> 1587 <p class="noindent">or by 1588<pre class="example"> <?program ntp-keygen> 1589</pre> 1590 <p class="noindent">Do not mix these styles within one configuration file. 1591 1592 <p>Compound values and carefully constructed string values may also be 1593specified using XML syntax: 1594<pre class="example"> <option-name> 1595 <sub-opt>...&lt;...&gt;...</sub-opt> 1596 </option-name> 1597</pre> 1598 <p class="noindent">yielding an <code>option-name.sub-opt</code> string value of 1599<pre class="example"> "...<...>..." 1600</pre> 1601 <p><code>AutoOpts</code> does not track suboptions. You simply note that it is a 1602hierarchicly valued option. <code>AutoOpts</code> does provide a means for searching 1603the associated name/value pair list (see: optionFindValue). 1604 1605 <p>The command line options relating to configuration and/or usage help are: 1606 1607<h5 class="subsubheading">version (-)</h5> 1608 1609<p>Print the program version to standard out, optionally with licensing 1610information, then exit 0. The optional argument specifies how much licensing 1611detail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument. 1612Only the first letter of the argument is examined: 1613 1614 <dl> 1615<dt><span class="samp">version</span><dd>Only print the version. This is the default. 1616<br><dt><span class="samp">copyright</span><dd>Name the copyright usage licensing terms. 1617<br><dt><span class="samp">verbose</span><dd>Print the full copyright usage licensing terms. 1618</dl> 1619 1620<div class="node"> 1621<p><hr> 1622<a name="ntp_002dkeygen-exit-status"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-Usage">ntp-keygen Usage</a>, 1623Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-config">ntp-keygen config</a>, 1624Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1625<br> 1626</div> 1627 1628<h4 class="subsection">ntp-keygen exit status</h4> 1629 1630<p>One of the following exit values will be returned: 1631 <dl> 1632<dt><span class="samp">0 (EXIT_SUCCESS)</span><dd>Successful program execution. 1633<br><dt><span class="samp">1 (EXIT_FAILURE)</span><dd>The operation failed or the command syntax was not valid. 1634<br><dt><span class="samp">66 (EX_NOINPUT)</span><dd>A specified configuration file could not be loaded. 1635<br><dt><span class="samp">70 (EX_SOFTWARE)</span><dd>libopts had an internal operational error. Please report 1636it to autogen-users@lists.sourceforge.net. Thank you. 1637</dl> 1638 <div class="node"> 1639<p><hr> 1640<a name="ntp_002dkeygen-Usage"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-Notes">ntp-keygen Notes</a>, 1641Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-exit-status">ntp-keygen exit status</a>, 1642Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1643<br> 1644</div> 1645 1646<h4 class="subsection">ntp-keygen Usage</h4> 1647 1648<div class="node"> 1649<p><hr> 1650<a name="ntp_002dkeygen-Notes"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dkeygen-Bugs">ntp-keygen Bugs</a>, 1651Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-Usage">ntp-keygen Usage</a>, 1652Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1653<br> 1654</div> 1655 1656<h4 class="subsection">ntp-keygen Notes</h4> 1657 1658<div class="node"> 1659<p><hr> 1660<a name="ntp_002dkeygen-Bugs"></a>Previous: <a rel="previous" accesskey="p" href="#ntp_002dkeygen-Notes">ntp-keygen Notes</a>, 1661Up: <a rel="up" accesskey="u" href="#ntp_002dkeygen-Invocation">ntp-keygen Invocation</a> 1662<br> 1663</div> 1664 1665<h4 class="subsection">ntp-keygen Bugs</h4> 1666 1667<div class="node"> 1668<p><hr> 1669<a name="Random-Seed-File"></a>Next: <a rel="next" accesskey="n" href="#Cryptographic-Data-Files">Cryptographic Data Files</a>, 1670Previous: <a rel="previous" accesskey="p" href="#Running-the-Program">Running the Program</a>, 1671Up: <a rel="up" accesskey="u" href="#Top">Top</a> 1672<br> 1673</div> 1674 1675<!-- node-name, next, previous, up --> 1676<h3 class="section">Random Seed File</h3> 1677 1678<p>All cryptographically sound key generation schemes must have means to 1679randomize the entropy seed used to initialize the internal 1680pseudo-random number generator used by the OpenSSL library routines. 1681If a site supports ssh, it is very likely that means to do this are 1682already available. 1683The entropy seed used by the OpenSSL library is contained in a file, 1684usually called <code>.rnd</code>, which must be available when 1685starting the <code>ntp-keygen</code> program or <code>ntpd</code> daemon. 1686 1687 <p>The OpenSSL library looks for the file using the path specified by the 1688<code>RANDFILE</code> environment variable in the user home directory, whether root 1689or some other user. 1690If the <code>RANDFILE</code> environment variable is not 1691present, the library looks for the <code>.rnd</code> file in the user home 1692directory. 1693Since both the <code>ntp-keygen</code> program and <code>ntpd</code> daemon must run 1694as root, the logical place to put this file is in <code>/.rnd</code> or 1695<code>/root/.rnd</code>. 1696If the file is not available or cannot be written, the program exits 1697with a message to the system log. 1698 1699<div class="node"> 1700<p><hr> 1701<a name="Cryptographic-Data-Files"></a>Previous: <a rel="previous" accesskey="p" href="#Random-Seed-File">Random Seed File</a>, 1702Up: <a rel="up" accesskey="u" href="#Top">Top</a> 1703<br> 1704</div> 1705 1706<!-- node-name, next, previous, up --> 1707<h3 class="section">Cryptographic Data Files</h3> 1708 1709<p>File and link names are in the <code>form ntpkey_key_name.fstamp</code>, 1710where <code>key</code> is the key or parameter type, 1711<code>name</code> is the host or group name and 1712<code>fstamp</code> is the filestamp (NTP seconds) when the file was created). 1713By convention, key names in generated file names include both upper and 1714lower case characters, while key names in generated link names include 1715only lower case characters. The filestamp is not used in generated link 1716names. 1717 1718 <p>The key name is a string defining the cryptographic key type. 1719Key types include public/private keys host and sign, certificate cert 1720and several challenge/response key types. 1721By convention, client files used for 1722challenges have a par subtype, as in the IFF challenge IFFpar, while 1723server files for responses have a key subtype, as in the GQ response 1724GQkey. 1725 1726 <p>All files begin with two nonencrypted lines. The first line contains 1727the file name in the format <code>ntpkey_key_host.fstamp</code>. 1728The second line contains the datestamp in conventional Unix date format. 1729Lines beginning with <code>#</code> are ignored. 1730 1731 <p>The remainder of the file contains cryptographic data encoded first 1732using ASN.1 rules, then encrypted using the DES-CBC algorithm with 1733given password and finally written in PEM-encoded printable ASCII text 1734preceded and followed by MIME content identifier lines. 1735 1736 <p>The format of the symmetric keys file, ordinarily named <code>ntp.keys</code>, 1737is somewhat different than the other files in the interest of backward 1738compatibility. 1739Ordinarily, the file is generated by this program, but 1740it can be constructed and edited using an ordinary text editor. 1741 1742<pre class="example"> # ntpkey_MD5key_hms.local.3564038757 1743 # Sun Dec 9 02:45:57 2012 1744 1745 1 MD5 "]!ghT%O;3)WJ,/Nc:>I # MD5 key 1746 2 MD5 lu+H^tF46BKR-6~pV_5 # MD5 key 1747 3 MD5 :lnoVsE%Yz*avh%EtNC # MD5 key 1748 4 MD5 |fdZrf0sF~^V # MD5 key 1749 5 MD5 IyAG>O"y"LmCRS!*bHC # MD5 key 1750 6 MD5 ">e\A # MD5 key 1751 7 MD5 c9x=M'CfLxax9v)PV-si # MD5 key 1752 8 MD5 E|=jvFVov?Bn|Ev=&aK\ # MD5 key 1753 9 MD5 T!c4UT&`(m$+m+B6,`Q0 # MD5 key 1754 10 MD5 JVF/1=)=IFbHbJQz..Cd # MD5 key 1755 11 SHA1 6dea311109529e436c2b4fccae9bc753c16d1b48 # SHA1 key 1756 12 SHA1 7076f373d86c4848c59ff8046e49cb7d614ec394 # SHA1 key 1757 13 SHA1 5f48b1b60591eb01b7cf1d33b7774f08d20262d3 # SHA1 key 1758 14 SHA1 eed5ab9d9497319ec60cf3781d52607e76720178 # SHA1 key 1759 15 SHA1 f283562611a04c964da8126296f5f8e58c3f85de # SHA1 key 1760 16 SHA1 1930da171297dd63549af50b29449de17dcf341f # SHA1 key 1761 17 SHA1 fee892110358cd4382322b889869e750db8e8a8f # SHA1 key 1762 18 SHA1 b5520c9fadd7ad3fd8bfa061c8821b65d029bb37 # SHA1 key 1763 19 SHA1 8c74fb440ec80f453ec6aaa62b9baed0ab723b92 # SHA1 key 1764 20 SHA1 6bc05f734306a189326000970c19b3910f403795 # SHA1 key 1765</pre> 1766 <p>Figure 1. Typical Symmetric Key File 1767 1768 <p>Figure 1 shows a typical symmetric keys file used by the reference 1769implementation. 1770Each line of the file contains three fields, first an 1771integer between 1 and 65534, inclusive, representing the key identifier 1772used in the server and peer configuration commands. 1773Next is the key type for the message digest algorithm, 1774which in the absence of the 1775OpenSSL library must be MD5 to designate the MD5 message digest 1776algorithm. 1777If the OpenSSL library is installed, the key type can be any 1778message digest algorithm supported by that library. 1779However, if 1780compatibility with FIPS 140-2 is required, the key type must be either 1781SHA or SHA1. 1782The key type can be changed using an ASCII text editor. 1783 1784 <p>An MD5 key consists of a printable ASCII string less than or equal to 178516 characters and terminated by whitespace or a # character. 1786An OpenSSL 1787key consists of a hex-encoded ASCII string of 40 characters, which is 1788truncated as necessary. 1789 1790 <p>Note that the keys used by the <code>ntpq</code> and <code>ntpdc</code> programs are 1791checked against passwords requested by the programs and entered by hand, 1792so it 1793is generally appropriate to specify these keys in human readable ASCII 1794format. 1795 1796 <p>The <code>ntp-keygen</code> program generates a MD5 symmetric keys file 1797<code>ntpkey_MD5key_hostname.filestamp</code>. 1798Since the file contains private 1799shared keys, it should be visible only to root and distributed by 1800secure means to other subnet hosts. 1801The NTP daemon loads the file <code>ntp.keys</code>, so <code>ntp-keygen</code> 1802installs a soft link from this name to the generated file. 1803Subsequently, similar soft links must be installed by 1804manual or automated means on the other subnet hosts. 1805While this file is 1806not used with the Autokey Version 2 protocol, it is needed to 1807authenticate some remote configuration commands used by the <code>ntpq</code> and 1808<code>ntpdc</code> utilities. 1809 1810</body></html> 1811 1812