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1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2 <html> 3 <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 6 <title>Ntp-keygen User’s Manual</title> 7 8 <meta name="description" content="Ntp-keygen User’s Manual"> 9 <meta name="keywords" content="Ntp-keygen User’s Manual"> 10 <meta name="resource-type" content="document"> 11 <meta name="distribution" content="global"> 12 <meta name="Generator" content="makeinfo"> 13 <link href="#Top" rel="start" title="Top"> 14 <link href="dir.html#Top" rel="up" title="(dir)"> 15 <style type="text/css"> 16 <!-- 17 a.summary-letter {text-decoration: none} 18 blockquote.indentedblock {margin-right: 0em} 19 blockquote.smallindentedblock {margin-right: 0em; font-size: smaller} 20 blockquote.smallquotation {font-size: smaller} 21 div.display {margin-left: 3.2em} 22 div.example {margin-left: 3.2em} 23 div.lisp {margin-left: 3.2em} 24 div.smalldisplay {margin-left: 3.2em} 25 div.smallexample {margin-left: 3.2em} 26 div.smalllisp {margin-left: 3.2em} 27 kbd {font-style: oblique} 28 pre.display {font-family: inherit} 29 pre.format {font-family: inherit} 30 pre.menu-comment {font-family: serif} 31 pre.menu-preformatted {font-family: serif} 32 pre.smalldisplay {font-family: inherit; font-size: smaller} 33 pre.smallexample {font-size: smaller} 34 pre.smallformat {font-family: inherit; font-size: smaller} 35 pre.smalllisp {font-size: smaller} 36 span.nolinebreak {white-space: nowrap} 37 span.roman {font-family: initial; font-weight: normal} 38 span.sansserif {font-family: sans-serif; font-weight: normal} 39 ul.no-bullet {list-style: none} 40 --> 41 </style> 42 43 44 </head> 45 46 <body lang="en"> 47 <h1 class="settitle" align="center">Ntp-keygen User’s Manual</h1> 48 49 50 51 52 53 <a name="SEC_Overview"></a> 54 <h2 class="shortcontents-heading">Short Table of Contents</h2> 55 56 <div class="shortcontents"> 57 <ul class="no-bullet"> 58 <li><a name="stoc-Description-1" href="#toc-Description-1">1 Description</a></li> 59 </ul> 60 </div> 61 62 63 <table class="menu" border="0" cellspacing="0"> 64 <tr><td align="left" valign="top">• <a href="#Description" accesskey="1">Description</a>:</td><td> </td><td align="left" valign="top"> 65 </td></tr> 66 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Invocation" accesskey="2">ntp-keygen Invocation</a>:</td><td> </td><td align="left" valign="top">Invoking ntp-keygen 67 </td></tr> 68 <tr><td align="left" valign="top">• <a href="#Running-the-Program" accesskey="3">Running the Program</a>:</td><td> </td><td align="left" valign="top"> 69 </td></tr> 70 <tr><td align="left" valign="top">• <a href="#Random-Seed-File" accesskey="4">Random Seed File</a>:</td><td> </td><td align="left" valign="top"> 71 </td></tr> 72 <tr><td align="left" valign="top">• <a href="#Cryptographic-Data-Files" accesskey="5">Cryptographic Data Files</a>:</td><td> </td><td align="left" valign="top"> 73 </td></tr> 74 </table> 75 76 <a name="Top"></a> 77 <div class="header"> 78 <p> 79 Next: <a href="#Description" accesskey="n" rel="next">Description</a>, Previous: <a href="dir.html#Top" accesskey="p" rel="prev">(dir)</a>, Up: <a href="dir.html#Top" accesskey="u" rel="up">(dir)</a> </p> 80 </div> 81 <a name="NTP-Key-Generation-Program-User-Manual"></a> 82 <h1 class="top">NTP Key Generation Program User Manual</h1> 83 84 <p>This document describes the use of the NTP Project’s <code>ntp-keygen</code> 85 program, that generates cryptographic data files used by the NTPv4 86 authentication and identity schemes. 87 It can generate message digest keys used in symmetric key cryptography and, 88 if the OpenSSL software 89 library has been installed, it can generate host keys, sign keys, 90 certificates, and identity keys and parameters used by the Autokey 91 public key cryptography. 92 The message digest keys file is generated in a 93 format compatible with NTPv3. 94 All other files are in PEM-encoded 95 printable ASCII format so they can be embedded as MIME attachments in 96 mail to other sites. 97 </p> 98 <p>This document applies to version 4.2.8p14 of <code>ntp-keygen</code>. 99 </p> 100 <table class="menu" border="0" cellspacing="0"> 101 <tr><td align="left" valign="top">• <a href="#Description" accesskey="1">Description</a>:</td><td> </td><td align="left" valign="top"> 102 </td></tr> 103 </table> 104 105 <hr> 106 <a name="Description"></a> 107 <div class="header"> 108 <p> 109 Next: <a href="#Running-the-Program" accesskey="n" rel="next">Running the Program</a>, Previous: <a href="#Top" accesskey="p" rel="prev">Top</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> </p> 110 </div> 111 <a name="Description-1"></a> 112 <h2 class="chapter">1 Description</h2> 113 114 <p>This program generates cryptographic data files used by the NTPv4 115 authentication and identity schemes. It can generate message digest 116 keys used in symmetric key cryptography and, if the OpenSSL software 117 library has been installed, it can generate host keys, sign keys, 118 certificates, and identity keys and parameters used by the Autokey 119 public key cryptography. The message digest keys file is generated in a 120 format compatible with NTPv3. All other files are in PEM-encoded 121 printable ASCII format so they can be embedded as MIME attachments in 122 mail to other sites. 123 </p> 124 <p>When used to generate message digest keys, the program produces a file 125 containing ten pseudo-random printable ASCII strings suitable for the 126 MD5 message digest algorithm included in the distribution. 127 If the 128 OpenSSL library is installed, it produces an additional ten hex-encoded 129 random bit strings suitable for the SHA1 and other message digest 130 algorithms. 131 The message digest keys file must be distributed and stored 132 using secure means beyond the scope of NTP itself. 133 Besides the keys 134 used for ordinary NTP associations, additional keys can be defined as 135 passwords for the ntpq and ntpdc utility programs. 136 </p> 137 <p>The remaining generated files are compatible with other OpenSSL 138 applications and other Public Key Infrastructure (PKI) resources. 139 Certificates generated by this program are compatible with extant 140 industry practice, although some users might find the interpretation of 141 X509v3 extension fields somewhat liberal. 142 However, the identity keys 143 are probably not compatible with anything other than Autokey. 144 </p> 145 <p>Some files used by this program are encrypted using a private password. 146 The <code>-p</code> option specifies the password for local encrypted files and the 147 <code>-q</code> option the password for encrypted files sent to remote sites. 148 If no password is specified, the host name returned by the Unix 149 <code>gethostname()</code> function, normally the DNS name of the host, is used. 150 </p> 151 <p>The <kbd>pw</kbd> option of the <code>crypto</code> configuration command 152 specifies the read password for previously encrypted local files. 153 This must match the local password used by this program. 154 If not specified, the host name is used. 155 Thus, if files are generated by this program without password, 156 they can be read back by ntpd without password, but only on the same 157 host. 158 </p> 159 <p>Normally, encrypted files for each host are generated by that host and 160 used only by that host, although exceptions exist as noted later on 161 this page. 162 The symmetric keys file, normally called <code>ntp.keys</code>, is 163 usually installed in <code>/etc</code>. 164 Other files and links are usually installed 165 in <code>/usr/local/etc</code>, which is normally in a shared filesystem in 166 NFS-mounted networks and cannot be changed by shared clients. 167 The location of the keys directory can be changed by the keysdir 168 configuration command in such cases. 169 Normally, this is in <code>/etc</code>. 170 </p> 171 <p>This program directs commentary and error messages to the standard 172 error stream <code>stderr</code> and remote files to the standard output stream 173 <code>stdout</code> where they can be piped to other applications or redirected to 174 files. 175 The names used for generated files and links all begin with the 176 string <code>ntpkey</code> and include the file type, 177 generating host and filestamp, 178 as described in the <a href="#Cryptographic-Data-Files">Cryptographic Data Files</a> section below. 179 </p> 180 <table class="menu" border="0" cellspacing="0"> 181 <tr><td align="left" valign="top">• <a href="#Running-the-Program" accesskey="1">Running the Program</a>:</td><td> </td><td align="left" valign="top"> 182 </td></tr> 183 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Invocation" accesskey="2">ntp-keygen Invocation</a>:</td><td> </td><td align="left" valign="top"> 184 </td></tr> 185 <tr><td align="left" valign="top">• <a href="#Random-Seed-File" accesskey="3">Random Seed File</a>:</td><td> </td><td align="left" valign="top"> 186 </td></tr> 187 <tr><td align="left" valign="top">• <a href="#Cryptographic-Data-Files" accesskey="4">Cryptographic Data Files</a>:</td><td> </td><td align="left" valign="top"> 188 </td></tr> 189 </table> 190 191 <hr> 192 <a name="Running-the-Program"></a> 193 <div class="header"> 194 <p> 195 Next: <a href="#Random-Seed-File" accesskey="n" rel="next">Random Seed File</a>, Previous: <a href="#Description" accesskey="p" rel="prev">Description</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> </p> 196 </div> 197 <a name="Running-the-Program-1"></a> 198 <h3 class="section">1.1 Running the Program</h3> 199 200 <p>To test and gain experience with Autokey concepts, log in as root and 201 change to the keys directory, usually <code>/usr/local/etc</code>. 202 When run for the 203 first time, or if all files with names beginning <code>ntpkey</code>] have been 204 removed, use the <code>ntp-keygen</code> command without arguments to generate a 205 default RSA host key and matching RSA-MD5 certificate with expiration 206 date one year hence. 207 If run again without options, the program uses the 208 existing keys and parameters and generates only a new certificate with 209 new expiration date one year hence. 210 </p> 211 <p>Run the command on as many hosts as necessary. 212 Designate one of them as the trusted host (TH) using <code>ntp-keygen</code> 213 with the <code>-T</code> option and configure 214 it to synchronize from reliable Internet servers. 215 Then configure the other hosts to synchronize to the TH directly or indirectly. 216 A certificate trail is created when Autokey asks the immediately 217 ascendant host towards the TH to sign its certificate, which is then 218 provided to the immediately descendant host on request. 219 All group hosts should have acyclic certificate trails ending on the TH. 220 </p> 221 <p>The host key is used to encrypt the cookie when required and so must be 222 RSA type. 223 By default, the host key is also the sign key used to encrypt signatures. 224 A different sign key can be assigned using the <code>-S</code> option 225 and this can be either RSA or DSA type. 226 By default, the signature 227 message digest type is MD5, but any combination of sign key type and 228 message digest type supported by the OpenSSL library can be specified 229 using the <code>-c</code> option. 230 </p> 231 <p>The rules say cryptographic media should be generated with proventic 232 filestamps, which means the host should already be synchronized before 233 this program is run. 234 This of course creates a chicken-and-egg problem 235 when the host is started for the first time. 236 Accordingly, the host time 237 should be set by some other means, such as eyeball-and-wristwatch, at 238 least so that the certificate lifetime is within the current year. 239 After that and when the host is synchronized to a proventic source, the 240 certificate should be re-generated. 241 </p> 242 <p>Additional information on trusted groups and identity schemes is on the 243 Autokey Public-Key Authentication page. 244 </p> 245 <hr> 246 <a name="ntp_002dkeygen-Invocation"></a> 247 <div class="header"> 248 <p> 249 Next: <a href="#Random-Seed-File" accesskey="n" rel="next">Random Seed File</a>, Previous: <a href="#Running-the-Program" accesskey="p" rel="prev">Running the Program</a>, Up: <a href="#Description" accesskey="u" rel="up">Description</a> </p> 250 </div> 251 <a name="Invoking-ntp_002dkeygen"></a> 252 <h3 class="section">1.2 Invoking ntp-keygen</h3> 253 <a name="index-ntp_002dkeygen"></a> 254 <a name="index-Create-a-NTP-host-key"></a> 255 256 257 258 <p>This program generates cryptographic data files used by the NTPv4 259 authentication and identification schemes. 260 It can generate message digest keys used in symmetric key cryptography and, 261 if the OpenSSL software library has been installed, it can generate host keys, 262 signing keys, certificates, and identity keys and parameters used in Autokey 263 public key cryptography. 264 These files are used for cookie encryption, 265 digital signature, and challenge/response identification algorithms 266 compatible with the Internet standard security infrastructure. 267 </p> 268 <p>The message digest symmetric keys file is generated in a format 269 compatible with NTPv3. 270 All other files are in PEM-encoded printable ASCII format, 271 so they can be embedded as MIME attachments in email to other sites 272 and certificate authorities. 273 By default, files are not encrypted. 274 </p> 275 <p>When used to generate message digest symmetric keys, the program 276 produces a file containing ten pseudo-random printable ASCII strings 277 suitable for the MD5 message digest algorithm included in the 278 distribution. 279 If the OpenSSL library is installed, it produces an additional ten 280 hex-encoded random bit strings suitable for SHA1, AES-128-CMAC, and 281 other message digest algorithms. 282 The message digest symmetric keys file must be distributed and stored 283 using secure means beyond the scope of NTP itself. 284 Besides the keys used for ordinary NTP associations, additional keys 285 can be defined as passwords for the 286 <code>ntpq(1ntpqmdoc)</code> 287 and 288 <code>ntpdc(1ntpdcmdoc)</code> 289 utility programs. 290 </p> 291 <p>The remaining generated files are compatible with other OpenSSL 292 applications and other Public Key Infrastructure (PKI) resources. 293 Certificates generated by this program are compatible with extant 294 industry practice, although some users might find the interpretation of 295 X509v3 extension fields somewhat liberal. 296 However, the identity keys are probably not compatible with anything 297 other than Autokey. 298 </p> 299 <p>Some files used by this program are encrypted using a private password. 300 The 301 <code>-p</code> 302 option specifies the read password for local encrypted files and the 303 <code>-q</code> 304 option the write password for encrypted files sent to remote sites. 305 If no password is specified, the host name returned by the Unix 306 <code>hostname(1)</code> 307 command, normally the DNS name of the host, is used as the the default read 308 password, for convenience. 309 The 310 <code>ntp-keygen</code> 311 program prompts for the password if it reads an encrypted file 312 and the password is missing or incorrect. 313 If an encrypted file is read successfully and 314 no write password is specified, the read password is used 315 as the write password by default. 316 </p> 317 <p>The 318 <code>pw</code> 319 option of the 320 <code>crypto</code> 321 <code>ntpd(1ntpdmdoc)</code> 322 configuration command specifies the read 323 password for previously encrypted local files. 324 This must match the local read password used by this program. 325 If not specified, the host name is used. 326 Thus, if files are generated by this program without an explicit password, 327 they can be read back by 328 <code>ntpd(1ntpdmdoc)</code> 329 without specifying an explicit password but only on the same host. 330 If the write password used for encryption is specified as the host name, 331 these files can be read by that host with no explicit password. 332 </p> 333 <p>Normally, encrypted files for each host are generated by that host and 334 used only by that host, although exceptions exist as noted later on 335 this page. 336 The symmetric keys file, normally called 337 <samp>ntp.keys</samp>, 338 is usually installed in 339 <samp>/etc</samp>. 340 Other files and links are usually installed in 341 <samp>/usr/local/etc</samp>, 342 which is normally in a shared filesystem in 343 NFS-mounted networks and cannot be changed by shared clients. 344 In these cases, NFS clients can specify the files in another 345 directory such as 346 <samp>/etc</samp> 347 using the 348 <code>keysdir</code> 349 <code>ntpd(1ntpdmdoc)</code> 350 configuration file command. 351 </p> 352 <p>This program directs commentary and error messages to the standard 353 error stream 354 <samp>stderr</samp> 355 and remote files to the standard output stream 356 <samp>stdout</samp> 357 where they can be piped to other applications or redirected to files. 358 The names used for generated files and links all begin with the 359 string 360 <samp>ntpkey*</samp> 361 and include the file type, generating host and filestamp, 362 as described in the 363 <a href="#Cryptographic-Data-Files">Cryptographic Data Files</a> 364 section below. 365 </p> 366 <table class="menu" border="0" cellspacing="0"> 367 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-usage" accesskey="1">ntp-keygen usage</a>:</td><td> </td><td align="left" valign="top"> 368 </td></tr> 369 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-imbits" accesskey="2">ntp-keygen imbits</a>:</td><td> </td><td align="left" valign="top"> 370 </td></tr> 371 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-certificate" accesskey="3">ntp-keygen certificate</a>:</td><td> </td><td align="left" valign="top"> 372 </td></tr> 373 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-cipher" accesskey="4">ntp-keygen cipher</a>:</td><td> </td><td align="left" valign="top"> 374 </td></tr> 375 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-id_002dkey" accesskey="5">ntp-keygen id-key</a>:</td><td> </td><td align="left" valign="top"> 376 </td></tr> 377 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-gq_002dparams" accesskey="6">ntp-keygen gq-params</a>:</td><td> </td><td align="left" valign="top"> 378 </td></tr> 379 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-host_002dkey" accesskey="7">ntp-keygen host-key</a>:</td><td> </td><td align="left" valign="top"> 380 </td></tr> 381 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-iffkey" accesskey="8">ntp-keygen iffkey</a>:</td><td> </td><td align="left" valign="top"> 382 </td></tr> 383 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-ident" accesskey="9">ntp-keygen ident</a>:</td><td> </td><td align="left" valign="top"> 384 </td></tr> 385 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-lifetime">ntp-keygen lifetime</a>:</td><td> </td><td align="left" valign="top"> 386 </td></tr> 387 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-modulus">ntp-keygen modulus</a>:</td><td> </td><td align="left" valign="top"> 388 </td></tr> 389 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-md5key">ntp-keygen md5key</a>:</td><td> </td><td align="left" valign="top"> 390 </td></tr> 391 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-pvt_002dcert">ntp-keygen pvt-cert</a>:</td><td> </td><td align="left" valign="top"> 392 </td></tr> 393 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-password">ntp-keygen password</a>:</td><td> </td><td align="left" valign="top"> 394 </td></tr> 395 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-export_002dpasswd">ntp-keygen export-passwd</a>:</td><td> </td><td align="left" valign="top"> 396 </td></tr> 397 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-subject_002dname">ntp-keygen subject-name</a>:</td><td> </td><td align="left" valign="top"> 398 </td></tr> 399 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-sign_002dkey">ntp-keygen sign-key</a>:</td><td> </td><td align="left" valign="top"> 400 </td></tr> 401 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-trusted_002dcert">ntp-keygen trusted-cert</a>:</td><td> </td><td align="left" valign="top"> 402 </td></tr> 403 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-mv_002dparams">ntp-keygen mv-params</a>:</td><td> </td><td align="left" valign="top"> 404 </td></tr> 405 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-mv_002dkeys">ntp-keygen mv-keys</a>:</td><td> </td><td align="left" valign="top"> 406 </td></tr> 407 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-config">ntp-keygen config</a>:</td><td> </td><td align="left" valign="top"> 408 </td></tr> 409 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-exit-status">ntp-keygen exit status</a>:</td><td> </td><td align="left" valign="top"> 410 </td></tr> 411 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Usage">ntp-keygen Usage</a>:</td><td> </td><td align="left" valign="top"> 412 </td></tr> 413 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Notes">ntp-keygen Notes</a>:</td><td> </td><td align="left" valign="top"> 414 </td></tr> 415 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Bugs">ntp-keygen Bugs</a>:</td><td> </td><td align="left" valign="top"> 416 </td></tr> 417 </table> 418 419 <a name="Running-the-Program-2"></a> 420 <h4 class="subsection">1.2.1 Running the Program</h4> 421 <p>The safest way to run the 422 <code>ntp-keygen</code> 423 program is logged in directly as root. 424 The recommended procedure is change to the 425 <kbd>keys</kbd> 426 directory, usually 427 <samp>/usr/local/etc</samp>, 428 then run the program. 429 </p> 430 <p>To test and gain experience with Autokey concepts, log in as root and 431 change to the 432 <kbd>keys</kbd> 433 directory, usually 434 <samp>/usr/local/etc</samp>. 435 When run for the first time, or if all files with names beginning with 436 <samp>ntpkey*</samp> 437 have been removed, use the 438 <code>ntp-keygen</code> 439 command without arguments to generate a default 440 <code>RSA</code> 441 host key and matching 442 <code>RSA-MD5</code> 443 certificate file with expiration date one year hence, 444 which is all that is necessary in many cases. 445 The program also generates soft links from the generic names 446 to the respective files. 447 If run again without options, the program uses the 448 existing keys and parameters and generates a new certificate file with 449 new expiration date one year hence, and soft link. 450 </p> 451 <p>The host key is used to encrypt the cookie when required and so must be 452 <code>RSA</code> 453 type. 454 By default, the host key is also the sign key used to encrypt signatures. 455 When necessary, a different sign key can be specified and this can be 456 either 457 <code>RSA</code> 458 or 459 <code>DSA</code> 460 type. 461 By default, the message digest type is 462 <code>MD5</code>, 463 but any combination 464 of sign key type and message digest type supported by the OpenSSL library 465 can be specified, including those using the 466 <code>AES128CMAC</code>, <code>MD2</code>, <code>MD5</code>, <code>MDC2</code>, <code>SHA</code>, <code>SHA1</code> 467 and 468 <code>RIPE160</code> 469 message digest algorithms. 470 However, the scheme specified in the certificate must be compatible 471 with the sign key. 472 Certificates using any digest algorithm are compatible with 473 <code>RSA</code> 474 sign keys; 475 however, only 476 <code>SHA</code> 477 and 478 <code>SHA1</code> 479 certificates are compatible with 480 <code>DSA</code> 481 sign keys. 482 </p> 483 <p>Private/public key files and certificates are compatible with 484 other OpenSSL applications and very likely other libraries as well. 485 Certificates or certificate requests derived from them should be compatible 486 with extant industry practice, although some users might find 487 the interpretation of X509v3 extension fields somewhat liberal. 488 However, the identification parameter files, although encoded 489 as the other files, are probably not compatible with anything other than Autokey. 490 </p> 491 <p>Running the program as other than root and using the Unix 492 <code>su(1)</code> 493 command 494 to assume root may not work properly, since by default the OpenSSL library 495 looks for the random seed file 496 <samp>.rnd</samp> 497 in the user home directory. 498 However, there should be only one 499 <samp>.rnd</samp>, 500 most conveniently 501 in the root directory, so it is convenient to define the 502 .Ev RANDFILE 503 environment variable used by the OpenSSL library as the path to 504 <samp>.rnd</samp>. 505 </p> 506 <p>Installing the keys as root might not work in NFS-mounted 507 shared file systems, as NFS clients may not be able to write 508 to the shared keys directory, even as root. 509 In this case, NFS clients can specify the files in another 510 directory such as 511 <samp>/etc</samp> 512 using the 513 <code>keysdir</code> 514 <code>ntpd(1ntpdmdoc)</code> 515 configuration file command. 516 There is no need for one client to read the keys and certificates 517 of other clients or servers, as these data are obtained automatically 518 by the Autokey protocol. 519 </p> 520 <p>Ordinarily, cryptographic files are generated by the host that uses them, 521 but it is possible for a trusted agent (TA) to generate these files 522 for other hosts; however, in such cases files should always be encrypted. 523 The subject name and trusted name default to the hostname 524 of the host generating the files, but can be changed by command line options. 525 It is convenient to designate the owner name and trusted name 526 as the subject and issuer fields, respectively, of the certificate. 527 The owner name is also used for the host and sign key files, 528 while the trusted name is used for the identity files. 529 </p> 530 <p>All files are installed by default in the keys directory 531 <samp>/usr/local/etc</samp>, 532 which is normally in a shared filesystem 533 in NFS-mounted networks. 534 The actual location of the keys directory 535 and each file can be overridden by configuration commands, 536 but this is not recommended. 537 Normally, the files for each host are generated by that host 538 and used only by that host, although exceptions exist 539 as noted later on this page. 540 </p> 541 <p>Normally, files containing private values, 542 including the host key, sign key and identification parameters, 543 are permitted root read/write-only; 544 while others containing public values are permitted world readable. 545 Alternatively, files containing private values can be encrypted 546 and these files permitted world readable, 547 which simplifies maintenance in shared file systems. 548 Since uniqueness is insured by the 549 <kbd>hostname</kbd> 550 and 551 <kbd>filestamp</kbd> 552 file name extensions, the files for an NTP server and 553 dependent clients can all be installed in the same shared directory. 554 </p> 555 <p>The recommended practice is to keep the file name extensions 556 when installing a file and to install a soft link 557 from the generic names specified elsewhere on this page 558 to the generated files. 559 This allows new file generations to be activated simply 560 by changing the link. 561 If a link is present, 562 <code>ntpd(1ntpdmdoc)</code> 563 follows it to the file name to extract the 564 <kbd>filestamp</kbd>. 565 If a link is not present, 566 <code>ntpd(1ntpdmdoc)</code> 567 extracts the 568 <kbd>filestamp</kbd> 569 from the file itself. 570 This allows clients to verify that the file and generation times 571 are always current. 572 The 573 <code>ntp-keygen</code> 574 program uses the same 575 <kbd>filestamp</kbd> 576 extension for all files generated 577 at one time, so each generation is distinct and can be readily 578 recognized in monitoring data. 579 </p> 580 <p>Run the command on as many hosts as necessary. 581 Designate one of them as the trusted host (TH) using 582 <code>ntp-keygen</code> 583 with the 584 <code>-T</code> 585 option and configure it to synchronize from reliable Internet servers. 586 Then configure the other hosts to synchronize to the TH directly or 587 indirectly. 588 A certificate trail is created when Autokey asks the immediately 589 ascendant host towards the TH to sign its certificate, which is then 590 provided to the immediately descendant host on request. 591 All group hosts should have acyclic certificate trails ending on the TH. 592 </p> 593 <p>The host key is used to encrypt the cookie when required and so must be 594 RSA type. 595 By default, the host key is also the sign key used to encrypt 596 signatures. 597 A different sign key can be assigned using the 598 <code>-S</code> 599 option and this can be either 600 <code>RSA</code> 601 or 602 <code>DSA</code> 603 type. 604 By default, the signature 605 message digest type is 606 <code>MD5</code>, 607 but any combination of sign key type and 608 message digest type supported by the OpenSSL library can be specified 609 using the 610 <code>-c</code> 611 option. 612 </p> 613 <p>The rules say cryptographic media should be generated with proventic 614 filestamps, which means the host should already be synchronized before 615 this program is run. 616 This of course creates a chicken-and-egg problem 617 when the host is started for the first time. 618 Accordingly, the host time 619 should be set by some other means, such as eyeball-and-wristwatch, at 620 least so that the certificate lifetime is within the current year. 621 After that and when the host is synchronized to a proventic source, the 622 certificate should be re-generated. 623 </p> 624 <p>Additional information on trusted groups and identity schemes is on the 625 “Autokey Public-Key Authentication” 626 page. 627 </p> 628 <p>File names begin with the prefix 629 <samp>ntpkey</samp>_ 630 and end with the suffix 631 <samp>_</samp><kbd>hostname</kbd>. <kbd>filestamp</kbd>, 632 where 633 <kbd>hostname</kbd> 634 is the owner name, usually the string returned 635 by the Unix 636 <code>hostname(1)</code> 637 command, and 638 <kbd>filestamp</kbd> 639 is the NTP seconds when the file was generated, in decimal digits. 640 This both guarantees uniqueness and simplifies maintenance 641 procedures, since all files can be quickly removed 642 by a 643 <code>rm</code> <samp>ntpkey*</samp> 644 command or all files generated 645 at a specific time can be removed by a 646 <code>rm</code> <samp>*</samp><kbd>filestamp</kbd> 647 command. 648 To further reduce the risk of misconfiguration, 649 the first two lines of a file contain the file name 650 and generation date and time as comments. 651 </p> 652 <a name="Trusted-Hosts-and-Groups"></a> 653 <h4 class="subsubsection">1.2.1.1 Trusted Hosts and Groups</h4> 654 <p>Each cryptographic configuration involves selection of a signature scheme 655 and identification scheme, called a cryptotype, 656 as explained in the 657 ‘Authentication Options’ 658 section of 659 <code>ntp.conf(5)</code>. 660 The default cryptotype uses 661 <code>RSA</code> 662 encryption, 663 <code>MD5</code> 664 message digest 665 and 666 <code>TC</code> 667 identification. 668 First, configure a NTP subnet including one or more low-stratum 669 trusted hosts from which all other hosts derive synchronization 670 directly or indirectly. 671 Trusted hosts have trusted certificates; 672 all other hosts have nontrusted certificates. 673 These hosts will automatically and dynamically build authoritative 674 certificate trails to one or more trusted hosts. 675 A trusted group is the set of all hosts that have, directly or indirectly, 676 a certificate trail ending at a trusted host. 677 The trail is defined by static configuration file entries 678 or dynamic means described on the 679 ‘Automatic NTP Configuration Options’ 680 section of 681 <code>ntp.conf(5)</code>. 682 </p> 683 <p>On each trusted host as root, change to the keys directory. 684 To insure a fresh fileset, remove all 685 <samp>ntpkey</samp> 686 files. 687 Then run 688 <code>ntp-keygen</code> 689 <code>-T</code> 690 to generate keys and a trusted certificate. 691 On all other hosts do the same, but leave off the 692 <code>-T</code> 693 flag to generate keys and nontrusted certificates. 694 When complete, start the NTP daemons beginning at the lowest stratum 695 and working up the tree. 696 It may take some time for Autokey to instantiate the certificate trails 697 throughout the subnet, but setting up the environment is completely automatic. 698 </p> 699 <p>If it is necessary to use a different sign key or different digest/signature 700 scheme than the default, run 701 <code>ntp-keygen</code> 702 with the 703 <code>-S</code> <kbd>type</kbd> 704 option, where 705 <kbd>type</kbd> 706 is either 707 <code>RSA</code> 708 or 709 <code>DSA</code>. 710 The most frequent need to do this is when a 711 <code>DSA</code>-signed 712 certificate is used. 713 If it is necessary to use a different certificate scheme than the default, 714 run 715 <code>ntp-keygen</code> 716 with the 717 <code>-c</code> <kbd>scheme</kbd> 718 option and selected 719 <kbd>scheme</kbd> 720 as needed. 721 If 722 <code>ntp-keygen</code> 723 is run again without these options, it generates a new certificate 724 using the same scheme and sign key, and soft link. 725 </p> 726 <p>After setting up the environment it is advisable to update certificates 727 from time to time, if only to extend the validity interval. 728 Simply run 729 <code>ntp-keygen</code> 730 with the same flags as before to generate new certificates 731 using existing keys, and soft links. 732 However, if the host or sign key is changed, 733 <code>ntpd(1ntpdmdoc)</code> 734 should be restarted. 735 When 736 <code>ntpd(1ntpdmdoc)</code> 737 is restarted, it loads any new files and restarts the protocol. 738 Other dependent hosts will continue as usual until signatures are refreshed, 739 at which time the protocol is restarted. 740 </p> 741 <a name="Identity-Schemes"></a> 742 <h4 class="subsubsection">1.2.1.2 Identity Schemes</h4> 743 <p>As mentioned on the Autonomous Authentication page, 744 the default 745 <code>TC</code> 746 identity scheme is vulnerable to a middleman attack. 747 However, there are more secure identity schemes available, 748 including 749 <code>PC</code>, <code>IFF</code>, <code>GQ</code> 750 and 751 <code>MV</code> 752 schemes described below. 753 These schemes are based on a TA, one or more trusted hosts 754 and some number of nontrusted hosts. 755 Trusted hosts prove identity using values provided by the TA, 756 while the remaining hosts prove identity using values provided 757 by a trusted host and certificate trails that end on that host. 758 The name of a trusted host is also the name of its sugroup 759 and also the subject and issuer name on its trusted certificate. 760 The TA is not necessarily a trusted host in this sense, but often is. 761 </p> 762 <p>In some schemes there are separate keys for servers and clients. 763 A server can also be a client of another server, 764 but a client can never be a server for another client. 765 In general, trusted hosts and nontrusted hosts that operate 766 as both server and client have parameter files that contain 767 both server and client keys. 768 Hosts that operate 769 only as clients have key files that contain only client keys. 770 </p> 771 <p>The PC scheme supports only one trusted host in the group. 772 On trusted host alice run 773 <code>ntp-keygen</code> 774 <code>-P</code> 775 <code>-p</code> <kbd>password</kbd> 776 to generate the host key file 777 <samp>ntpkey</samp>_ <code>RSA</code> <samp>key_alice.</samp> <kbd>filestamp</kbd> 778 and trusted private certificate file 779 <samp>ntpkey</samp>_ <code>RSA-MD5</code> <code>_</code> <samp>cert_alice.</samp> <kbd>filestamp</kbd>, 780 and soft links. 781 Copy both files to all group hosts; 782 they replace the files which would be generated in other schemes. 783 On each host 784 <kbd>bob</kbd> 785 install a soft link from the generic name 786 <samp>ntpkey_host_</samp><kbd>bob</kbd> 787 to the host key file and soft link 788 <samp>ntpkey_cert_</samp><kbd>bob</kbd> 789 to the private certificate file. 790 Note the generic links are on bob, but point to files generated 791 by trusted host alice. 792 In this scheme it is not possible to refresh 793 either the keys or certificates without copying them 794 to all other hosts in the group, and recreating the soft links. 795 </p> 796 <p>For the 797 <code>IFF</code> 798 scheme proceed as in the 799 <code>TC</code> 800 scheme to generate keys 801 and certificates for all group hosts, then for every trusted host in the group, 802 generate the 803 <code>IFF</code> 804 parameter file. 805 On trusted host alice run 806 <code>ntp-keygen</code> 807 <code>-T</code> 808 <code>-I</code> 809 <code>-p</code> <kbd>password</kbd> 810 to produce her parameter file 811 <samp>ntpkey_IFFpar_alice.</samp><kbd>filestamp</kbd>, 812 which includes both server and client keys. 813 Copy this file to all group hosts that operate as both servers 814 and clients and install a soft link from the generic 815 <samp>ntpkey_iff_alice</samp> 816 to this file. 817 If there are no hosts restricted to operate only as clients, 818 there is nothing further to do. 819 As the 820 <code>IFF</code> 821 scheme is independent 822 of keys and certificates, these files can be refreshed as needed. 823 </p> 824 <p>If a rogue client has the parameter file, it could masquerade 825 as a legitimate server and present a middleman threat. 826 To eliminate this threat, the client keys can be extracted 827 from the parameter file and distributed to all restricted clients. 828 After generating the parameter file, on alice run 829 <code>ntp-keygen</code> 830 <code>-e</code> 831 and pipe the output to a file or email program. 832 Copy or email this file to all restricted clients. 833 On these clients install a soft link from the generic 834 <samp>ntpkey_iff_alice</samp> 835 to this file. 836 To further protect the integrity of the keys, 837 each file can be encrypted with a secret password. 838 </p> 839 <p>For the 840 <code>GQ</code> 841 scheme proceed as in the 842 <code>TC</code> 843 scheme to generate keys 844 and certificates for all group hosts, then for every trusted host 845 in the group, generate the 846 <code>IFF</code> 847 parameter file. 848 On trusted host alice run 849 <code>ntp-keygen</code> 850 <code>-T</code> 851 <code>-G</code> 852 <code>-p</code> <kbd>password</kbd> 853 to produce her parameter file 854 <samp>ntpkey_GQpar_alice.</samp><kbd>filestamp</kbd>, 855 which includes both server and client keys. 856 Copy this file to all group hosts and install a soft link 857 from the generic 858 <samp>ntpkey_gq_alice</samp> 859 to this file. 860 In addition, on each host 861 <kbd>bob</kbd> 862 install a soft link 863 from generic 864 <samp>ntpkey_gq_</samp><kbd>bob</kbd> 865 to this file. 866 As the 867 <code>GQ</code> 868 scheme updates the 869 <code>GQ</code> 870 parameters file and certificate 871 at the same time, keys and certificates can be regenerated as needed. 872 </p> 873 <p>For the 874 <code>MV</code> 875 scheme, proceed as in the 876 <code>TC</code> 877 scheme to generate keys 878 and certificates for all group hosts. 879 For illustration assume trish is the TA, alice one of several trusted hosts 880 and bob one of her clients. 881 On TA trish run 882 <code>ntp-keygen</code> 883 <code>-V</code> <kbd>n</kbd> 884 <code>-p</code> <kbd>password</kbd>, 885 where 886 <kbd>n</kbd> 887 is the number of revokable keys (typically 5) to produce 888 the parameter file 889 <samp>ntpkeys_MVpar_trish.</samp><kbd>filestamp</kbd> 890 and client key files 891 <samp>ntpkeys_MVkey</samp><kbd>d</kbd> <kbd>_</kbd> <samp>trish.</samp> <kbd>filestamp</kbd> 892 where 893 <kbd>d</kbd> 894 is the key number (0 < 895 <kbd>d</kbd> 896 < 897 <kbd>n</kbd>). 898 Copy the parameter file to alice and install a soft link 899 from the generic 900 <samp>ntpkey_mv_alice</samp> 901 to this file. 902 Copy one of the client key files to alice for later distribution 903 to her clients. 904 It does not matter which client key file goes to alice, 905 since they all work the same way. 906 Alice copies the client key file to all of her clients. 907 On client bob install a soft link from generic 908 <samp>ntpkey_mvkey_bob</samp> 909 to the client key file. 910 As the 911 <code>MV</code> 912 scheme is independent of keys and certificates, 913 these files can be refreshed as needed. 914 </p> 915 <a name="Command-Line-Options"></a> 916 <h4 class="subsubsection">1.2.1.3 Command Line Options</h4> 917 <dl compact="compact"> 918 <dt><code>-b</code> <code>--imbits</code>= <kbd>modulus</kbd></dt> 919 <dd><p>Set the number of bits in the identity modulus for generating identity keys to 920 <kbd>modulus</kbd> 921 bits. 922 The number of bits in the identity modulus defaults to 256, but can be set to 923 values from 256 to 2048 (32 to 256 octets). 924 Use the larger moduli with caution, as this can consume considerable computing 925 resources and increases the size of authenticated packets. 926 </p></dd> 927 <dt><code>-c</code> <code>--certificate</code>= <kbd>scheme</kbd></dt> 928 <dd><p>Select certificate signature encryption/message digest scheme. 929 The 930 <kbd>scheme</kbd> 931 can be one of the following: 932 <code>RSA-MD2</code>, <code>RSA-MD5</code>, <code>RSA-MDC2</code>, <code>RSA-SHA</code>, <code>RSA-SHA1</code>, <code>RSA-RIPEMD160</code>, <code>DSA-SHA</code>, 933 or 934 <code>DSA-SHA1</code>. 935 Note that 936 <code>RSA</code> 937 schemes must be used with an 938 <code>RSA</code> 939 sign key and 940 <code>DSA</code> 941 schemes must be used with a 942 <code>DSA</code> 943 sign key. 944 The default without this option is 945 <code>RSA-MD5</code>. 946 If compatibility with FIPS 140-2 is required, either the 947 <code>DSA-SHA</code> 948 or 949 <code>DSA-SHA1</code> 950 scheme must be used. 951 </p></dd> 952 <dt><code>-C</code> <code>--cipher</code>= <kbd>cipher</kbd></dt> 953 <dd><p>Select the OpenSSL cipher to encrypt the files containing private keys. 954 The default without this option is three-key triple DES in CBC mode, 955 <code>des-ede3-cbc</code>. 956 The 957 <code>openssl</code> <code>-h</code> 958 command provided with OpenSSL displays available ciphers. 959 </p></dd> 960 <dt><code>-d</code> <code>--debug-level</code></dt> 961 <dd><p>Increase debugging verbosity level. 962 This option displays the cryptographic data produced in eye-friendly billboards. 963 </p></dd> 964 <dt><code>-D</code> <code>--set-debug-level</code>= <kbd>level</kbd></dt> 965 <dd><p>Set the debugging verbosity to 966 <kbd>level</kbd>. 967 This option displays the cryptographic data produced in eye-friendly billboards. 968 </p></dd> 969 <dt><code>-e</code> <code>--id-key</code></dt> 970 <dd><p>Write the 971 <code>IFF</code> 972 or 973 <code>GQ</code> 974 public parameters from the 975 <kbd>IFFkey</kbd> <kbd>or</kbd> <kbd>GQkey</kbd> 976 client keys file previously specified 977 as unencrypted data to the standard output stream 978 <samp>stdout</samp>. 979 This is intended for automatic key distribution by email. 980 </p></dd> 981 <dt><code>-G</code> <code>--gq-params</code></dt> 982 <dd><p>Generate a new encrypted 983 <code>GQ</code> 984 parameters and key file for the Guillou-Quisquater (GQ) identity scheme. 985 This option is mutually exclusive with the 986 <code>-I</code> 987 and 988 <code>-V</code> 989 options. 990 </p></dd> 991 <dt><code>-H</code> <code>--host-key</code></dt> 992 <dd><p>Generate a new encrypted 993 <code>RSA</code> 994 public/private host key file. 995 </p></dd> 996 <dt><code>-I</code> <code>--iffkey</code></dt> 997 <dd><p>Generate a new encrypted 998 <code>IFF</code> 999 key file for the Schnorr (IFF) identity scheme. 1000 This option is mutually exclusive with the 1001 <code>-G</code> 1002 and 1003 Fl V 1004 options. 1005 </p></dd> 1006 <dt><code>-i</code> <code>--ident</code>= <kbd>group</kbd></dt> 1007 <dd><p>Set the optional Autokey group name to 1008 <kbd>group</kbd>. 1009 This is used in the identity scheme parameter file names of 1010 <code>IFF</code>, <code>GQ</code>, 1011 and 1012 <code>MV</code> 1013 client parameters files. 1014 In that role, the default is the host name if no group is provided. 1015 The group name, if specified using 1016 <code>-i</code> 1017 or 1018 <code>-s</code> 1019 following an 1020 ‘@’ 1021 character, is also used in certificate subject and issuer names in the form 1022 <kbd>host</kbd> <kbd>@</kbd> <kbd>group</kbd> 1023 and should match the group specified via 1024 <code>crypto</code> <code>ident</code> 1025 or 1026 <code>server</code> <code>ident</code> 1027 in the ntpd configuration file. 1028 </p></dd> 1029 <dt><code>-l</code> <code>--lifetime</code>= <kbd>days</kbd></dt> 1030 <dd><p>Set the lifetime for certificate expiration to 1031 <kbd>days</kbd>. 1032 The default lifetime is one year (365 days). 1033 </p></dd> 1034 <dt><code>-m</code> <code>--modulus</code>= <kbd>bits</kbd></dt> 1035 <dd><p>Set the number of bits in the prime modulus for generating files to 1036 <kbd>bits</kbd>. 1037 The modulus defaults to 512, but can be set from 256 to 2048 (32 to 256 octets). 1038 Use the larger moduli with caution, as this can consume considerable computing 1039 resources and increases the size of authenticated packets. 1040 </p></dd> 1041 <dt><code>-M</code> <code>--md5key</code></dt> 1042 <dd><p>Generate a new symmetric keys file containing 10 1043 <code>MD5</code> 1044 keys, and if OpenSSL is available, 10 1045 <code>SHA</code> 1046 keys. 1047 An 1048 <code>MD5</code> 1049 key is a string of 20 random printable ASCII characters, while a 1050 <code>SHA</code> 1051 key is a string of 40 random hex digits. 1052 The file can be edited using a text editor to change the key type or key content. 1053 This option is mutually exclusive with all other options. 1054 </p></dd> 1055 <dt><code>-p</code> <code>--password</code>= <kbd>passwd</kbd></dt> 1056 <dd><p>Set the password for reading and writing encrypted files to 1057 <kbd>passwd</kbd>. 1058 These include the host, sign and identify key files. 1059 By default, the password is the string returned by the Unix 1060 <code>hostname</code> 1061 command. 1062 </p></dd> 1063 <dt><code>-P</code> <code>--pvt-cert</code></dt> 1064 <dd><p>Generate a new private certificate used by the 1065 <code>PC</code> 1066 identity scheme. 1067 By default, the program generates public certificates. 1068 Note: the PC identity scheme is not recommended for new installations. 1069 </p></dd> 1070 <dt><code>-q</code> <code>--export-passwd</code>= <kbd>passwd</kbd></dt> 1071 <dd><p>Set the password for writing encrypted 1072 <code>IFF</code>, <code>GQ</code> <code>and</code> <code>MV</code> 1073 identity files redirected to 1074 <samp>stdout</samp> 1075 to 1076 <kbd>passwd</kbd>. 1077 In effect, these files are decrypted with the 1078 <code>-p</code> 1079 password, then encrypted with the 1080 <code>-q</code> 1081 password. 1082 By default, the password is the string returned by the Unix 1083 <code>hostname</code> 1084 command. 1085 </p></dd> 1086 <dt><code>-s</code> <code>--subject-key</code>= <code>[host]</code> <code>[@ <kbd>group</kbd>]</code></dt> 1087 <dd><p>Specify the Autokey host name, where 1088 <kbd>host</kbd> 1089 is the optional host name and 1090 <kbd>group</kbd> 1091 is the optional group name. 1092 The host name, and if provided, group name are used in 1093 <kbd>host</kbd> <kbd>@</kbd> <kbd>group</kbd> 1094 form as certificate subject and issuer. 1095 Specifying 1096 <code>-s</code> <code>-@</code> <kbd>group</kbd> 1097 is allowed, and results in leaving the host name unchanged, as with 1098 <code>-i</code> <kbd>group</kbd>. 1099 The group name, or if no group is provided, the host name are also used in the 1100 file names of 1101 <code>IFF</code>, <code>GQ</code>, 1102 and 1103 <code>MV</code> 1104 identity scheme client parameter files. 1105 If 1106 <kbd>host</kbd> 1107 is not specified, the default host name is the string returned by the Unix 1108 <code>hostname</code> 1109 command. 1110 </p></dd> 1111 <dt><code>-S</code> <code>--sign-key</code>= <code>[<code>RSA</code> | <code>DSA</code>]</code></dt> 1112 <dd><p>Generate a new encrypted public/private sign key file of the specified type. 1113 By default, the sign key is the host key and has the same type. 1114 If compatibility with FIPS 140-2 is required, the sign key type must be 1115 <code>DSA</code>. 1116 </p></dd> 1117 <dt><code>-T</code> <code>--trusted-cert</code></dt> 1118 <dd><p>Generate a trusted certificate. 1119 By default, the program generates a non-trusted certificate. 1120 </p></dd> 1121 <dt><code>-V</code> <code>--mv-params</code> <kbd>nkeys</kbd></dt> 1122 <dd><p>Generate 1123 <kbd>nkeys</kbd> 1124 encrypted server keys and parameters for the Mu-Varadharajan (MV) 1125 identity scheme. 1126 This option is mutually exclusive with the 1127 <code>-I</code> 1128 and 1129 <code>-G</code> 1130 options. 1131 Note: support for this option should be considered a work in progress. 1132 </p></dd> 1133 </dl> 1134 1135 <a name="Random-Seed-File-1"></a> 1136 <h4 class="subsubsection">1.2.1.4 Random Seed File</h4> 1137 <p>All cryptographically sound key generation schemes must have means 1138 to randomize the entropy seed used to initialize 1139 the internal pseudo-random number generator used 1140 by the library routines. 1141 The OpenSSL library uses a designated random seed file for this purpose. 1142 The file must be available when starting the NTP daemon and 1143 <code>ntp-keygen</code> 1144 program. 1145 If a site supports OpenSSL or its companion OpenSSH, 1146 it is very likely that means to do this are already available. 1147 </p> 1148 <p>It is important to understand that entropy must be evolved 1149 for each generation, for otherwise the random number sequence 1150 would be predictable. 1151 Various means dependent on external events, such as keystroke intervals, 1152 can be used to do this and some systems have built-in entropy sources. 1153 Suitable means are described in the OpenSSL software documentation, 1154 but are outside the scope of this page. 1155 </p> 1156 <p>The entropy seed used by the OpenSSL library is contained in a file, 1157 usually called 1158 <samp>.rnd</samp>, 1159 which must be available when starting the NTP daemon 1160 or the 1161 <code>ntp-keygen</code> 1162 program. 1163 The NTP daemon will first look for the file 1164 using the path specified by the 1165 <code>randfile</code> 1166 subcommand of the 1167 <code>crypto</code> 1168 configuration command. 1169 If not specified in this way, or when starting the 1170 <code>ntp-keygen</code> 1171 program, 1172 the OpenSSL library will look for the file using the path specified 1173 by the 1174 .Ev RANDFILE 1175 environment variable in the user home directory, 1176 whether root or some other user. 1177 If the 1178 .Ev RANDFILE 1179 environment variable is not present, 1180 the library will look for the 1181 <samp>.rnd</samp> 1182 file in the user home directory. 1183 Since both the 1184 <code>ntp-keygen</code> 1185 program and 1186 <code>ntpd(1ntpdmdoc)</code> 1187 daemon must run as root, the logical place to put this file is in 1188 <samp>/.rnd</samp> 1189 or 1190 <samp>/root/.rnd</samp>. 1191 If the file is not available or cannot be written, 1192 the daemon exits with a message to the system log and the program 1193 exits with a suitable error message. 1194 </p> 1195 <a name="Cryptographic-Data-Files-1"></a> 1196 <h4 class="subsubsection">1.2.1.5 Cryptographic Data Files</h4> 1197 <p>All file formats begin with two nonencrypted lines. 1198 The first line contains the file name, including the generated host name 1199 and filestamp, in the format 1200 <samp>ntpkey_</samp><kbd>key</kbd> <kbd>_</kbd> <kbd>name</kbd>. <kbd>filestamp</kbd>, 1201 where 1202 <kbd>key</kbd> 1203 is the key or parameter type, 1204 <kbd>name</kbd> 1205 is the host or group name and 1206 <kbd>filestamp</kbd> 1207 is the filestamp (NTP seconds) when the file was created. 1208 By convention, 1209 <kbd>key</kbd> 1210 names in generated file names include both upper and lower case 1211 characters, while 1212 <kbd>key</kbd> 1213 names in generated link names include only lower case characters. 1214 The filestamp is not used in generated link names. 1215 The second line contains the datestamp in conventional Unix 1216 <samp>date</samp> 1217 format. 1218 Lines beginning with 1219 ‘#’ 1220 are considered comments and ignored by the 1221 <code>ntp-keygen</code> 1222 program and 1223 <code>ntpd(1ntpdmdoc)</code> 1224 daemon. 1225 </p> 1226 <p>The remainder of the file contains cryptographic data, encoded first using ASN.1 1227 rules, then encrypted if necessary, and finally written in PEM-encoded 1228 printable ASCII text, preceded and followed by MIME content identifier lines. 1229 </p> 1230 <p>The format of the symmetric keys file, ordinarily named 1231 <samp>ntp.keys</samp>, 1232 is somewhat different than the other files in the interest of backward compatibility. 1233 Ordinarily, the file is generated by this program, but it can be constructed 1234 and edited using an ordinary text editor. 1235 </p><pre class="verbatim"># ntpkey_MD5key_bk.ntp.org.3595864945 1236 # Thu Dec 12 19:22:25 2013 1237 1238 1 MD5 L";Nw<\`.I<f4U0)247"i # MD5 key 1239 2 MD5 &>l0%XXK9O'51VwV<xq~ # MD5 key 1240 3 MD5 lb4zLW~d^!K:]RsD'qb6 # MD5 key 1241 4 MD5 Yue:tL[+vR)M\`n~bY,'? # MD5 key 1242 5 MD5 B;fx'Kgr/&4ZTbL6=RxA # MD5 key 1243 6 MD5 4eYwa\`o@}3i@@@@V@@..R9!l # MD5 key 1244 7 MD5 \`A.([h+;wTQ|xfi%Sn_! # MD5 key 1245 8 MD5 45:V,r4]l6y^JH6"Sh?F # MD5 key 1246 9 MD5 3-5vcn*6l29DS?Xdsg)* # MD5 key 1247 10 MD5 2late4Me # MD5 key 1248 11 SHA1 a27872d3030a9025b8446c751b4551a7629af65c # SHA1 key 1249 12 SHA1 21bc3b4865dbb9e920902abdccb3e04ff97a5e74 # SHA1 key 1250 13 SHA1 2b7736fe24fef5ba85ae11594132ab5d6f6daba9 # SHA1 key 1251 14 SHA a5332809c8878dd3a5b918819108a111509aeceb # SHA key 1252 15 MD2 2fe16c88c760ff2f16d4267e36c1aa6c926e6964 # MD2 key 1253 16 MD4 b2691811dc19cfc0e2f9bcacd74213f29812183d # MD4 key 1254 17 MD5 e4d6735b8bdad58ec5ffcb087300a17f7fef1f7c # MD5 key 1255 18 MDC2 a8d5e2315c025bf3a79174c87fbd10477de2eabc # MDC2 key 1256 19 RIPEMD160 77ca332cafb30e3cafb174dcd5b80ded7ba9b3d2 # RIPEMD160 key 1257 20 AES128CMAC f92ff73eee86c1e7dc638d6489a04e4e555af878 # AES128CMAC key 1258 </pre><div class="example"> 1259 <pre class="example">Figure 1. Typical Symmetric Key File 1260 </pre></div> 1261 1262 <p>Figure 1 shows a typical symmetric keys file used by the reference 1263 implementation. 1264 Following the header the keys are entered one per line in the format 1265 </p><div class="example"> 1266 <pre class="example"><kbd>keyno</kbd> <kbd>type</kbd> <kbd>key</kbd> 1267 </pre></div> 1268 <p>where 1269 <kbd>keyno</kbd> 1270 is a positive integer in the range 1-65535; 1271 <kbd>type</kbd> 1272 is the key type for the message digest algorithm, which in the absence of the 1273 OpenSSL library must be 1274 <code>MD5</code> 1275 to designate the MD5 message digest algorithm; 1276 if the OpenSSL library is installed, the key type can be any 1277 message digest algorithm supported by that library; 1278 however, if compatibility with FIPS 140-2 is required, 1279 the key type must be either 1280 <code>SHA</code> 1281 or 1282 <code>SHA1</code>; 1283 <kbd>key</kbd> 1284 is the key itself, 1285 which is a printable ASCII string 20 characters or less in length: 1286 each character is chosen from the 93 printable characters 1287 in the range 0x21 through 0x7e ( 1288 ‘’! 1289 through 1290 ‘~’ 1291 ) excluding space and the 1292 ‘#’ 1293 character, and terminated by whitespace or a 1294 ‘#’ 1295 character. 1296 An OpenSSL key consists of a hex-encoded ASCII string of 40 characters, which 1297 is truncated as necessary. 1298 </p> 1299 <p>Note that the keys used by the 1300 <code>ntpq(1ntpqmdoc)</code> 1301 and 1302 <code>ntpdc(1ntpdcmdoc)</code> 1303 programs 1304 are checked against passwords requested by the programs 1305 and entered by hand, so it is generally appropriate to specify these keys 1306 in human readable ASCII format. 1307 </p> 1308 <p>The 1309 <code>ntp-keygen</code> 1310 program generates a symmetric keys file 1311 <samp>ntpkey_MD5key_</samp><kbd>hostname</kbd>. <kbd>filestamp</kbd>. 1312 Since the file contains private shared keys, 1313 it should be visible only to root and distributed by secure means 1314 to other subnet hosts. 1315 The NTP daemon loads the file 1316 <samp>ntp.keys</samp>, 1317 so 1318 <code>ntp-keygen</code> 1319 installs a soft link from this name to the generated file. 1320 Subsequently, similar soft links must be installed by manual 1321 or automated means on the other subnet hosts. 1322 While this file is not used with the Autokey Version 2 protocol, 1323 it is needed to authenticate some remote configuration commands 1324 used by the 1325 <code>ntpq(1ntpqmdoc)</code> 1326 and 1327 <code>ntpdc(1ntpdcmdoc)</code> 1328 utilities. 1329 </p> 1330 <p>This section was generated by <strong>AutoGen</strong>, 1331 using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntp-keygen</code> program. 1332 This software is released under the NTP license, <http://ntp.org/license>;. 1333 </p> 1334 <table class="menu" border="0" cellspacing="0"> 1335 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-usage" accesskey="1">ntp-keygen usage</a>:</td><td> </td><td align="left" valign="top">ntp-keygen help/usage (<samp>--help</samp>) 1336 </td></tr> 1337 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-imbits" accesskey="2">ntp-keygen imbits</a>:</td><td> </td><td align="left" valign="top">imbits option (-b) 1338 </td></tr> 1339 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-certificate" accesskey="3">ntp-keygen certificate</a>:</td><td> </td><td align="left" valign="top">certificate option (-c) 1340 </td></tr> 1341 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-cipher" accesskey="4">ntp-keygen cipher</a>:</td><td> </td><td align="left" valign="top">cipher option (-C) 1342 </td></tr> 1343 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-id_002dkey" accesskey="5">ntp-keygen id-key</a>:</td><td> </td><td align="left" valign="top">id-key option (-e) 1344 </td></tr> 1345 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-gq_002dparams" accesskey="6">ntp-keygen gq-params</a>:</td><td> </td><td align="left" valign="top">gq-params option (-G) 1346 </td></tr> 1347 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-host_002dkey" accesskey="7">ntp-keygen host-key</a>:</td><td> </td><td align="left" valign="top">host-key option (-H) 1348 </td></tr> 1349 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-iffkey" accesskey="8">ntp-keygen iffkey</a>:</td><td> </td><td align="left" valign="top">iffkey option (-I) 1350 </td></tr> 1351 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-ident" accesskey="9">ntp-keygen ident</a>:</td><td> </td><td align="left" valign="top">ident option (-i) 1352 </td></tr> 1353 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-lifetime">ntp-keygen lifetime</a>:</td><td> </td><td align="left" valign="top">lifetime option (-l) 1354 </td></tr> 1355 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-modulus">ntp-keygen modulus</a>:</td><td> </td><td align="left" valign="top">modulus option (-m) 1356 </td></tr> 1357 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-md5key">ntp-keygen md5key</a>:</td><td> </td><td align="left" valign="top">md5key option (-M) 1358 </td></tr> 1359 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-pvt_002dcert">ntp-keygen pvt-cert</a>:</td><td> </td><td align="left" valign="top">pvt-cert option (-P) 1360 </td></tr> 1361 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-password">ntp-keygen password</a>:</td><td> </td><td align="left" valign="top">password option (-p) 1362 </td></tr> 1363 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-export_002dpasswd">ntp-keygen export-passwd</a>:</td><td> </td><td align="left" valign="top">export-passwd option (-q) 1364 </td></tr> 1365 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-subject_002dname">ntp-keygen subject-name</a>:</td><td> </td><td align="left" valign="top">subject-name option (-s) 1366 </td></tr> 1367 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-sign_002dkey">ntp-keygen sign-key</a>:</td><td> </td><td align="left" valign="top">sign-key option (-S) 1368 </td></tr> 1369 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-trusted_002dcert">ntp-keygen trusted-cert</a>:</td><td> </td><td align="left" valign="top">trusted-cert option (-T) 1370 </td></tr> 1371 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-mv_002dparams">ntp-keygen mv-params</a>:</td><td> </td><td align="left" valign="top">mv-params option (-V) 1372 </td></tr> 1373 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-mv_002dkeys">ntp-keygen mv-keys</a>:</td><td> </td><td align="left" valign="top">mv-keys option (-v) 1374 </td></tr> 1375 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-config">ntp-keygen config</a>:</td><td> </td><td align="left" valign="top">presetting/configuring ntp-keygen 1376 </td></tr> 1377 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-exit-status">ntp-keygen exit status</a>:</td><td> </td><td align="left" valign="top">exit status 1378 </td></tr> 1379 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Usage">ntp-keygen Usage</a>:</td><td> </td><td align="left" valign="top">Usage 1380 </td></tr> 1381 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Notes">ntp-keygen Notes</a>:</td><td> </td><td align="left" valign="top">Notes 1382 </td></tr> 1383 <tr><td align="left" valign="top">• <a href="#ntp_002dkeygen-Bugs">ntp-keygen Bugs</a>:</td><td> </td><td align="left" valign="top">Bugs 1384 </td></tr> 1385 </table> 1386 1387 <hr> 1388 <a name="ntp_002dkeygen-usage"></a> 1389 <div class="header"> 1390 <p> 1391 Next: <a href="#ntp_002dkeygen-imbits" accesskey="n" rel="next">ntp-keygen imbits</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1392 </div> 1393 <a name="ntp_002dkeygen-help_002fusage-_0028_002d_002dhelp_0029"></a> 1394 <h4 class="subsection">1.2.2 ntp-keygen help/usage (<samp>--help</samp>)</h4> 1395 <a name="index-ntp_002dkeygen-help"></a> 1396 1397 <p>This is the automatically generated usage text for ntp-keygen. 1398 </p> 1399 <p>The text printed is the same whether selected with the <code>help</code> option 1400 (<samp>--help</samp>) or the <code>more-help</code> option (<samp>--more-help</samp>). <code>more-help</code> will print 1401 the usage text by passing it through a pager program. 1402 <code>more-help</code> is disabled on platforms without a working 1403 <code>fork(2)</code> function. The <code>PAGER</code> environment variable is 1404 used to select the program, defaulting to <samp>more</samp>. Both will exit 1405 with a status code of 0. 1406 </p> 1407 <div class="example"> 1408 <pre class="example">ntp-keygen (ntp) - Create a NTP host key - Ver. 4.2.8p13 1409 Usage: ntp-keygen [ -<flag> [<val>] | --<name>[{=| }<val>] ]... 1410 Flg Arg Option-Name Description 1411 -b Num imbits identity modulus bits 1412 - it must be in the range: 1413 256 to 2048 1414 -c Str certificate certificate scheme 1415 -C Str cipher privatekey cipher 1416 -d no debug-level Increase debug verbosity level 1417 - may appear multiple times 1418 -D Num set-debug-level Set the debug verbosity level 1419 - may appear multiple times 1420 -e no id-key Write IFF or GQ identity keys 1421 -G no gq-params Generate GQ parameters and keys 1422 -H no host-key generate RSA host key 1423 -I no iffkey generate IFF parameters 1424 -i Str ident set Autokey group name 1425 -l Num lifetime set certificate lifetime 1426 -m Num modulus prime modulus 1427 - it must be in the range: 1428 256 to 2048 1429 -M no md5key generate symmetric keys 1430 -P no pvt-cert generate PC private certificate 1431 -p Str password local private password 1432 -q Str export-passwd export IFF or GQ group keys with password 1433 -s Str subject-name set host and optionally group name 1434 -S Str sign-key generate sign key (RSA or DSA) 1435 -T no trusted-cert trusted certificate (TC scheme) 1436 -V Num mv-params generate <num> MV parameters 1437 -v Num mv-keys update <num> MV keys 1438 opt version output version information and exit 1439 -? no help display extended usage information and exit 1440 -! no more-help extended usage information passed thru pager 1441 -> opt save-opts save the option state to a config file 1442 -< Str load-opts load options from a config file 1443 - disabled as '--no-load-opts' 1444 - may appear multiple times 1445 1446 Options are specified by doubled hyphens and their name or by a single 1447 hyphen and the flag character. 1448 1449 1450 The following option preset mechanisms are supported: 1451 - reading file $HOME/.ntprc 1452 - reading file ./.ntprc 1453 - examining environment variables named NTP_KEYGEN_* 1454 1455 Please send bug reports to: <http://bugs.ntp.org, bugs (a] ntp.org> 1456 </pre></div> 1457 1458 <hr> 1459 <a name="ntp_002dkeygen-imbits"></a> 1460 <div class="header"> 1461 <p> 1462 Next: <a href="#ntp_002dkeygen-certificate" accesskey="n" rel="next">ntp-keygen certificate</a>, Previous: <a href="#ntp_002dkeygen-usage" accesskey="p" rel="prev">ntp-keygen usage</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1463 </div> 1464 <a name="imbits-option-_0028_002db_0029"></a> 1465 <h4 class="subsection">1.2.3 imbits option (-b)</h4> 1466 <a name="index-ntp_002dkeygen_002dimbits"></a> 1467 1468 <p>This is the “identity modulus bits” option. 1469 This option takes a number argument <samp>imbits</samp>. 1470 </p> 1471 <p>This option has some usage constraints. It: 1472 </p><ul> 1473 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1474 </li></ul> 1475 1476 <p>The number of bits in the identity modulus. The default is 256. 1477 </p><hr> 1478 <a name="ntp_002dkeygen-certificate"></a> 1479 <div class="header"> 1480 <p> 1481 Next: <a href="#ntp_002dkeygen-cipher" accesskey="n" rel="next">ntp-keygen cipher</a>, Previous: <a href="#ntp_002dkeygen-imbits" accesskey="p" rel="prev">ntp-keygen imbits</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1482 </div> 1483 <a name="certificate-option-_0028_002dc_0029"></a> 1484 <h4 class="subsection">1.2.4 certificate option (-c)</h4> 1485 <a name="index-ntp_002dkeygen_002dcertificate"></a> 1486 1487 <p>This is the “certificate scheme” option. 1488 This option takes a string argument <samp>scheme</samp>. 1489 </p> 1490 <p>This option has some usage constraints. It: 1491 </p><ul> 1492 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1493 </li></ul> 1494 1495 <p>scheme is one of 1496 RSA-MD2, RSA-MD5, RSA-MDC2, RSA-SHA, RSA-SHA1, RSA-RIPEMD160, 1497 DSA-SHA, or DSA-SHA1. 1498 </p> 1499 <p>Select the certificate signature encryption/message digest scheme. 1500 Note that RSA schemes must be used with a RSA sign key and DSA 1501 schemes must be used with a DSA sign key. The default without 1502 this option is RSA-MD5. 1503 </p><hr> 1504 <a name="ntp_002dkeygen-cipher"></a> 1505 <div class="header"> 1506 <p> 1507 Next: <a href="#ntp_002dkeygen-id_002dkey" accesskey="n" rel="next">ntp-keygen id-key</a>, Previous: <a href="#ntp_002dkeygen-certificate" accesskey="p" rel="prev">ntp-keygen certificate</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1508 </div> 1509 <a name="cipher-option-_0028_002dC_0029"></a> 1510 <h4 class="subsection">1.2.5 cipher option (-C)</h4> 1511 <a name="index-ntp_002dkeygen_002dcipher"></a> 1512 1513 <p>This is the “privatekey cipher” option. 1514 This option takes a string argument <samp>cipher</samp>. 1515 </p> 1516 <p>This option has some usage constraints. It: 1517 </p><ul> 1518 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1519 </li></ul> 1520 1521 <p>Select the cipher which is used to encrypt the files containing 1522 private keys. The default is three-key triple DES in CBC mode, 1523 equivalent to "<code>-C des-ede3-cbc</code>". The openssl tool lists ciphers 1524 available in "<code>openssl -h</code>" output. 1525 </p><hr> 1526 <a name="ntp_002dkeygen-id_002dkey"></a> 1527 <div class="header"> 1528 <p> 1529 Next: <a href="#ntp_002dkeygen-gq_002dparams" accesskey="n" rel="next">ntp-keygen gq-params</a>, Previous: <a href="#ntp_002dkeygen-cipher" accesskey="p" rel="prev">ntp-keygen cipher</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1530 </div> 1531 <a name="id_002dkey-option-_0028_002de_0029"></a> 1532 <h4 class="subsection">1.2.6 id-key option (-e)</h4> 1533 <a name="index-ntp_002dkeygen_002did_002dkey"></a> 1534 1535 <p>This is the “write iff or gq identity keys” option. 1536 </p> 1537 <p>This option has some usage constraints. It: 1538 </p><ul> 1539 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1540 </li></ul> 1541 1542 <p>Write the public parameters from the IFF or GQ client keys to 1543 the standard output. 1544 This is intended for automatic key distribution by email. 1545 </p><hr> 1546 <a name="ntp_002dkeygen-gq_002dparams"></a> 1547 <div class="header"> 1548 <p> 1549 Next: <a href="#ntp_002dkeygen-host_002dkey" accesskey="n" rel="next">ntp-keygen host-key</a>, Previous: <a href="#ntp_002dkeygen-id_002dkey" accesskey="p" rel="prev">ntp-keygen id-key</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1550 </div> 1551 <a name="gq_002dparams-option-_0028_002dG_0029"></a> 1552 <h4 class="subsection">1.2.7 gq-params option (-G)</h4> 1553 <a name="index-ntp_002dkeygen_002dgq_002dparams"></a> 1554 1555 <p>This is the “generate gq parameters and keys” option. 1556 </p> 1557 <p>This option has some usage constraints. It: 1558 </p><ul> 1559 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1560 </li></ul> 1561 1562 <p>Generate parameters and keys for the GQ identification scheme, 1563 obsoleting any that may exist. 1564 </p><hr> 1565 <a name="ntp_002dkeygen-host_002dkey"></a> 1566 <div class="header"> 1567 <p> 1568 Next: <a href="#ntp_002dkeygen-iffkey" accesskey="n" rel="next">ntp-keygen iffkey</a>, Previous: <a href="#ntp_002dkeygen-gq_002dparams" accesskey="p" rel="prev">ntp-keygen gq-params</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1569 </div> 1570 <a name="host_002dkey-option-_0028_002dH_0029"></a> 1571 <h4 class="subsection">1.2.8 host-key option (-H)</h4> 1572 <a name="index-ntp_002dkeygen_002dhost_002dkey"></a> 1573 1574 <p>This is the “generate rsa host key” option. 1575 </p> 1576 <p>This option has some usage constraints. It: 1577 </p><ul> 1578 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1579 </li></ul> 1580 1581 <p>Generate new host keys, obsoleting any that may exist. 1582 </p><hr> 1583 <a name="ntp_002dkeygen-iffkey"></a> 1584 <div class="header"> 1585 <p> 1586 Next: <a href="#ntp_002dkeygen-ident" accesskey="n" rel="next">ntp-keygen ident</a>, Previous: <a href="#ntp_002dkeygen-host_002dkey" accesskey="p" rel="prev">ntp-keygen host-key</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1587 </div> 1588 <a name="iffkey-option-_0028_002dI_0029"></a> 1589 <h4 class="subsection">1.2.9 iffkey option (-I)</h4> 1590 <a name="index-ntp_002dkeygen_002diffkey"></a> 1591 1592 <p>This is the “generate iff parameters” option. 1593 </p> 1594 <p>This option has some usage constraints. It: 1595 </p><ul> 1596 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1597 </li></ul> 1598 1599 <p>Generate parameters for the IFF identification scheme, obsoleting 1600 any that may exist. 1601 </p><hr> 1602 <a name="ntp_002dkeygen-ident"></a> 1603 <div class="header"> 1604 <p> 1605 Next: <a href="#ntp_002dkeygen-lifetime" accesskey="n" rel="next">ntp-keygen lifetime</a>, Previous: <a href="#ntp_002dkeygen-iffkey" accesskey="p" rel="prev">ntp-keygen iffkey</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1606 </div> 1607 <a name="ident-option-_0028_002di_0029"></a> 1608 <h4 class="subsection">1.2.10 ident option (-i)</h4> 1609 <a name="index-ntp_002dkeygen_002dident"></a> 1610 1611 <p>This is the “set autokey group name” option. 1612 This option takes a string argument <samp>group</samp>. 1613 </p> 1614 <p>This option has some usage constraints. It: 1615 </p><ul> 1616 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1617 </li></ul> 1618 1619 <p>Set the optional Autokey group name to name. This is used in 1620 the file name of IFF, GQ, and MV client parameters files. In 1621 that role, the default is the host name if this option is not 1622 provided. The group name, if specified using <code>-i/--ident</code> or 1623 using <code>-s/--subject-name</code> following an ’<code>@</code>’ character, 1624 is also a part of the self-signed host certificate subject and 1625 issuer names in the form <code>host@group</code> and should match the 1626 ’<code>crypto ident</code>’ or ’<code>server ident</code>’ configuration in the 1627 <code>ntpd</code> configuration file. 1628 </p><hr> 1629 <a name="ntp_002dkeygen-lifetime"></a> 1630 <div class="header"> 1631 <p> 1632 Next: <a href="#ntp_002dkeygen-modulus" accesskey="n" rel="next">ntp-keygen modulus</a>, Previous: <a href="#ntp_002dkeygen-ident" accesskey="p" rel="prev">ntp-keygen ident</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1633 </div> 1634 <a name="lifetime-option-_0028_002dl_0029"></a> 1635 <h4 class="subsection">1.2.11 lifetime option (-l)</h4> 1636 <a name="index-ntp_002dkeygen_002dlifetime"></a> 1637 1638 <p>This is the “set certificate lifetime” option. 1639 This option takes a number argument <samp>lifetime</samp>. 1640 </p> 1641 <p>This option has some usage constraints. It: 1642 </p><ul> 1643 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1644 </li></ul> 1645 1646 <p>Set the certificate expiration to lifetime days from now. 1647 </p><hr> 1648 <a name="ntp_002dkeygen-modulus"></a> 1649 <div class="header"> 1650 <p> 1651 Next: <a href="#ntp_002dkeygen-md5key" accesskey="n" rel="next">ntp-keygen md5key</a>, Previous: <a href="#ntp_002dkeygen-lifetime" accesskey="p" rel="prev">ntp-keygen lifetime</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1652 </div> 1653 <a name="modulus-option-_0028_002dm_0029"></a> 1654 <h4 class="subsection">1.2.12 modulus option (-m)</h4> 1655 <a name="index-ntp_002dkeygen_002dmodulus"></a> 1656 1657 <p>This is the “prime modulus” option. 1658 This option takes a number argument <samp>modulus</samp>. 1659 </p> 1660 <p>This option has some usage constraints. It: 1661 </p><ul> 1662 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1663 </li></ul> 1664 1665 <p>The number of bits in the prime modulus. The default is 512. 1666 </p><hr> 1667 <a name="ntp_002dkeygen-md5key"></a> 1668 <div class="header"> 1669 <p> 1670 Next: <a href="#ntp_002dkeygen-pvt_002dcert" accesskey="n" rel="next">ntp-keygen pvt-cert</a>, Previous: <a href="#ntp_002dkeygen-modulus" accesskey="p" rel="prev">ntp-keygen modulus</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1671 </div> 1672 <a name="md5key-option-_0028_002dM_0029"></a> 1673 <h4 class="subsection">1.2.13 md5key option (-M)</h4> 1674 <a name="index-ntp_002dkeygen_002dmd5key"></a> 1675 1676 <p>This is the “generate symmetric keys” option. 1677 Generate symmetric keys, obsoleting any that may exist. 1678 </p><hr> 1679 <a name="ntp_002dkeygen-pvt_002dcert"></a> 1680 <div class="header"> 1681 <p> 1682 Next: <a href="#ntp_002dkeygen-password" accesskey="n" rel="next">ntp-keygen password</a>, Previous: <a href="#ntp_002dkeygen-md5key" accesskey="p" rel="prev">ntp-keygen md5key</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1683 </div> 1684 <a name="pvt_002dcert-option-_0028_002dP_0029"></a> 1685 <h4 class="subsection">1.2.14 pvt-cert option (-P)</h4> 1686 <a name="index-ntp_002dkeygen_002dpvt_002dcert"></a> 1687 1688 <p>This is the “generate pc private certificate” option. 1689 </p> 1690 <p>This option has some usage constraints. It: 1691 </p><ul> 1692 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1693 </li></ul> 1694 1695 <p>Generate a private certificate. By default, the program generates 1696 public certificates. 1697 </p><hr> 1698 <a name="ntp_002dkeygen-password"></a> 1699 <div class="header"> 1700 <p> 1701 Next: <a href="#ntp_002dkeygen-export_002dpasswd" accesskey="n" rel="next">ntp-keygen export-passwd</a>, Previous: <a href="#ntp_002dkeygen-pvt_002dcert" accesskey="p" rel="prev">ntp-keygen pvt-cert</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1702 </div> 1703 <a name="password-option-_0028_002dp_0029"></a> 1704 <h4 class="subsection">1.2.15 password option (-p)</h4> 1705 <a name="index-ntp_002dkeygen_002dpassword"></a> 1706 1707 <p>This is the “local private password” option. 1708 This option takes a string argument <samp>passwd</samp>. 1709 </p> 1710 <p>This option has some usage constraints. It: 1711 </p><ul> 1712 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1713 </li></ul> 1714 1715 <p>Local files containing private data are encrypted with the 1716 DES-CBC algorithm and the specified password. The same password 1717 must be specified to the local ntpd via the "crypto pw password" 1718 configuration command. The default password is the local 1719 hostname. 1720 </p><hr> 1721 <a name="ntp_002dkeygen-export_002dpasswd"></a> 1722 <div class="header"> 1723 <p> 1724 Next: <a href="#ntp_002dkeygen-subject_002dname" accesskey="n" rel="next">ntp-keygen subject-name</a>, Previous: <a href="#ntp_002dkeygen-password" accesskey="p" rel="prev">ntp-keygen password</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1725 </div> 1726 <a name="export_002dpasswd-option-_0028_002dq_0029"></a> 1727 <h4 class="subsection">1.2.16 export-passwd option (-q)</h4> 1728 <a name="index-ntp_002dkeygen_002dexport_002dpasswd"></a> 1729 1730 <p>This is the “export iff or gq group keys with password” option. 1731 This option takes a string argument <samp>passwd</samp>. 1732 </p> 1733 <p>This option has some usage constraints. It: 1734 </p><ul> 1735 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1736 </li></ul> 1737 1738 <p>Export IFF or GQ identity group keys to the standard output, 1739 encrypted with the DES-CBC algorithm and the specified password. 1740 The same password must be specified to the remote ntpd via the 1741 "crypto pw password" configuration command. See also the option 1742 –id-key (-e) for unencrypted exports. 1743 </p><hr> 1744 <a name="ntp_002dkeygen-subject_002dname"></a> 1745 <div class="header"> 1746 <p> 1747 Next: <a href="#ntp_002dkeygen-sign_002dkey" accesskey="n" rel="next">ntp-keygen sign-key</a>, Previous: <a href="#ntp_002dkeygen-export_002dpasswd" accesskey="p" rel="prev">ntp-keygen export-passwd</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1748 </div> 1749 <a name="subject_002dname-option-_0028_002ds_0029"></a> 1750 <h4 class="subsection">1.2.17 subject-name option (-s)</h4> 1751 <a name="index-ntp_002dkeygen_002dsubject_002dname"></a> 1752 1753 <p>This is the “set host and optionally group name” option. 1754 This option takes a string argument <samp>host@group</samp>. 1755 </p> 1756 <p>This option has some usage constraints. It: 1757 </p><ul> 1758 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1759 </li></ul> 1760 1761 <p>Set the Autokey host name, and optionally, group name specified 1762 following an ’<code>@</code>’ character. The host name is used in the file 1763 name of generated host and signing certificates, without the 1764 group name. The host name, and if provided, group name are used 1765 in <code>host@group</code> form for the host certificate subject and issuer 1766 fields. Specifying ’<code>-s @group</code>’ is allowed, and results in 1767 leaving the host name unchanged while appending <code>@group</code> to the 1768 subject and issuer fields, as with <code>-i group</code>. The group name, or 1769 if not provided, the host name are also used in the file names 1770 of IFF, GQ, and MV client parameter files. 1771 </p><hr> 1772 <a name="ntp_002dkeygen-sign_002dkey"></a> 1773 <div class="header"> 1774 <p> 1775 Next: <a href="#ntp_002dkeygen-trusted_002dcert" accesskey="n" rel="next">ntp-keygen trusted-cert</a>, Previous: <a href="#ntp_002dkeygen-subject_002dname" accesskey="p" rel="prev">ntp-keygen subject-name</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1776 </div> 1777 <a name="sign_002dkey-option-_0028_002dS_0029"></a> 1778 <h4 class="subsection">1.2.18 sign-key option (-S)</h4> 1779 <a name="index-ntp_002dkeygen_002dsign_002dkey"></a> 1780 1781 <p>This is the “generate sign key (rsa or dsa)” option. 1782 This option takes a string argument <samp>sign</samp>. 1783 </p> 1784 <p>This option has some usage constraints. It: 1785 </p><ul> 1786 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1787 </li></ul> 1788 1789 <p>Generate a new sign key of the designated type, obsoleting any 1790 that may exist. By default, the program uses the host key as the 1791 sign key. 1792 </p><hr> 1793 <a name="ntp_002dkeygen-trusted_002dcert"></a> 1794 <div class="header"> 1795 <p> 1796 Next: <a href="#ntp_002dkeygen-mv_002dparams" accesskey="n" rel="next">ntp-keygen mv-params</a>, Previous: <a href="#ntp_002dkeygen-sign_002dkey" accesskey="p" rel="prev">ntp-keygen sign-key</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1797 </div> 1798 <a name="trusted_002dcert-option-_0028_002dT_0029"></a> 1799 <h4 class="subsection">1.2.19 trusted-cert option (-T)</h4> 1800 <a name="index-ntp_002dkeygen_002dtrusted_002dcert"></a> 1801 1802 <p>This is the “trusted certificate (tc scheme)” option. 1803 </p> 1804 <p>This option has some usage constraints. It: 1805 </p><ul> 1806 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1807 </li></ul> 1808 1809 <p>Generate a trusted certificate. By default, the program generates 1810 a non-trusted certificate. 1811 </p><hr> 1812 <a name="ntp_002dkeygen-mv_002dparams"></a> 1813 <div class="header"> 1814 <p> 1815 Next: <a href="#ntp_002dkeygen-mv_002dkeys" accesskey="n" rel="next">ntp-keygen mv-keys</a>, Previous: <a href="#ntp_002dkeygen-trusted_002dcert" accesskey="p" rel="prev">ntp-keygen trusted-cert</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1816 </div> 1817 <a name="mv_002dparams-option-_0028_002dV_0029"></a> 1818 <h4 class="subsection">1.2.20 mv-params option (-V)</h4> 1819 <a name="index-ntp_002dkeygen_002dmv_002dparams"></a> 1820 1821 <p>This is the “generate <num> mv parameters” option. 1822 This option takes a number argument <samp>num</samp>. 1823 </p> 1824 <p>This option has some usage constraints. It: 1825 </p><ul> 1826 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1827 </li></ul> 1828 1829 <p>Generate parameters and keys for the Mu-Varadharajan (MV) 1830 identification scheme. 1831 </p><hr> 1832 <a name="ntp_002dkeygen-mv_002dkeys"></a> 1833 <div class="header"> 1834 <p> 1835 Next: <a href="#ntp_002dkeygen-config" accesskey="n" rel="next">ntp-keygen config</a>, Previous: <a href="#ntp_002dkeygen-mv_002dparams" accesskey="p" rel="prev">ntp-keygen mv-params</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1836 </div> 1837 <a name="mv_002dkeys-option-_0028_002dv_0029"></a> 1838 <h4 class="subsection">1.2.21 mv-keys option (-v)</h4> 1839 <a name="index-ntp_002dkeygen_002dmv_002dkeys"></a> 1840 1841 <p>This is the “update <num> mv keys” option. 1842 This option takes a number argument <samp>num</samp>. 1843 </p> 1844 <p>This option has some usage constraints. It: 1845 </p><ul> 1846 <li> must be compiled in by defining <code>AUTOKEY</code> during the compilation. 1847 </li></ul> 1848 1849 <p>This option has no ‘<samp>doc</samp>’ documentation. 1850 </p> 1851 1852 <hr> 1853 <a name="ntp_002dkeygen-config"></a> 1854 <div class="header"> 1855 <p> 1856 Next: <a href="#ntp_002dkeygen-exit-status" accesskey="n" rel="next">ntp-keygen exit status</a>, Previous: <a href="#ntp_002dkeygen-mv_002dkeys" accesskey="p" rel="prev">ntp-keygen mv-keys</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1857 </div> 1858 <a name="presetting_002fconfiguring-ntp_002dkeygen"></a> 1859 <h4 class="subsection">1.2.22 presetting/configuring ntp-keygen</h4> 1860 1861 <p>Any option that is not marked as <i>not presettable</i> may be preset by 1862 loading 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 1863 the options listed above in upper case and segmented with underscores. 1864 The <code>NTP-KEYGEN</code> variable will be tokenized and parsed like 1865 the command line. The remaining variables are tested for existence and their 1866 values are treated like option arguments. 1867 </p> 1868 1869 <p><code>libopts</code> will search in 2 places for configuration files: 1870 </p><ul> 1871 <li> $HOME 1872 </li><li> $PWD 1873 </li></ul> 1874 <p>The environment variables <code>HOME</code>, and <code>PWD</code> 1875 are expanded and replaced when <samp>ntp-keygen</samp> runs. 1876 For any of these that are plain files, they are simply processed. 1877 For any that are directories, then a file named <samp>.ntprc</samp> is searched for 1878 within that directory and processed. 1879 </p> 1880 <p>Configuration files may be in a wide variety of formats. 1881 The basic format is an option name followed by a value (argument) on the 1882 same line. Values may be separated from the option name with a colon, 1883 equal sign or simply white space. Values may be continued across multiple 1884 lines by escaping the newline with a backslash. 1885 </p> 1886 <p>Multiple programs may also share the same initialization file. 1887 Common options are collected at the top, followed by program specific 1888 segments. The segments are separated by lines like: 1889 </p><div class="example"> 1890 <pre class="example">[NTP-KEYGEN] 1891 </pre></div> 1892 <p>or by 1893 </p><div class="example"> 1894 <pre class="example"><?program ntp-keygen> 1895 </pre></div> 1896 <p>Do not mix these styles within one configuration file. 1897 </p> 1898 <p>Compound values and carefully constructed string values may also be 1899 specified using XML syntax: 1900 </p><div class="example"> 1901 <pre class="example"><option-name> 1902 <sub-opt>...&lt;...&gt;...</sub-opt> 1903 </option-name> 1904 </pre></div> 1905 <p>yielding an <code>option-name.sub-opt</code> string value of 1906 </p><div class="example"> 1907 <pre class="example">"...<...>..." 1908 </pre></div> 1909 <p><code>AutoOpts</code> does not track suboptions. You simply note that it is a 1910 hierarchicly valued option. <code>AutoOpts</code> does provide a means for searching 1911 the associated name/value pair list (see: optionFindValue). 1912 </p> 1913 <p>The command line options relating to configuration and/or usage help are: 1914 </p> 1915 <a name="version-_0028_002d_0029"></a> 1916 <h4 class="subsubheading">version (-)</h4> 1917 1918 <p>Print the program version to standard out, optionally with licensing 1919 information, then exit 0. The optional argument specifies how much licensing 1920 detail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument. 1921 Only the first letter of the argument is examined: 1922 </p> 1923 <dl compact="compact"> 1924 <dt>‘<samp>version</samp>’</dt> 1925 <dd><p>Only print the version. This is the default. 1926 </p></dd> 1927 <dt>‘<samp>copyright</samp>’</dt> 1928 <dd><p>Name the copyright usage licensing terms. 1929 </p></dd> 1930 <dt>‘<samp>verbose</samp>’</dt> 1931 <dd><p>Print the full copyright usage licensing terms. 1932 </p></dd> 1933 </dl> 1934 1935 <hr> 1936 <a name="ntp_002dkeygen-exit-status"></a> 1937 <div class="header"> 1938 <p> 1939 Next: <a href="#ntp_002dkeygen-Usage" accesskey="n" rel="next">ntp-keygen Usage</a>, Previous: <a href="#ntp_002dkeygen-config" accesskey="p" rel="prev">ntp-keygen config</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1940 </div> 1941 <a name="ntp_002dkeygen-exit-status-1"></a> 1942 <h4 class="subsection">1.2.23 ntp-keygen exit status</h4> 1943 1944 <p>One of the following exit values will be returned: 1945 </p><dl compact="compact"> 1946 <dt>‘<samp>0 (EXIT_SUCCESS)</samp>’</dt> 1947 <dd><p>Successful program execution. 1948 </p></dd> 1949 <dt>‘<samp>1 (EXIT_FAILURE)</samp>’</dt> 1950 <dd><p>The operation failed or the command syntax was not valid. 1951 </p></dd> 1952 <dt>‘<samp>66 (EX_NOINPUT)</samp>’</dt> 1953 <dd><p>A specified configuration file could not be loaded. 1954 </p></dd> 1955 <dt>‘<samp>70 (EX_SOFTWARE)</samp>’</dt> 1956 <dd><p>libopts had an internal operational error. Please report 1957 it to autogen-users (a] lists.sourceforge.net. Thank you. 1958 </p></dd> 1959 </dl> 1960 <hr> 1961 <a name="ntp_002dkeygen-Usage"></a> 1962 <div class="header"> 1963 <p> 1964 Next: <a href="#ntp_002dkeygen-Notes" accesskey="n" rel="next">ntp-keygen Notes</a>, Previous: <a href="#ntp_002dkeygen-exit-status" accesskey="p" rel="prev">ntp-keygen exit status</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1965 </div> 1966 <a name="ntp_002dkeygen-Usage-1"></a> 1967 <h4 class="subsection">1.2.24 ntp-keygen Usage</h4> 1968 <hr> 1969 <a name="ntp_002dkeygen-Notes"></a> 1970 <div class="header"> 1971 <p> 1972 Next: <a href="#ntp_002dkeygen-Bugs" accesskey="n" rel="next">ntp-keygen Bugs</a>, Previous: <a href="#ntp_002dkeygen-Usage" accesskey="p" rel="prev">ntp-keygen Usage</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1973 </div> 1974 <a name="ntp_002dkeygen-Notes-1"></a> 1975 <h4 class="subsection">1.2.25 ntp-keygen Notes</h4> 1976 <hr> 1977 <a name="ntp_002dkeygen-Bugs"></a> 1978 <div class="header"> 1979 <p> 1980 Previous: <a href="#ntp_002dkeygen-Notes" accesskey="p" rel="prev">ntp-keygen Notes</a>, Up: <a href="#ntp_002dkeygen-Invocation" accesskey="u" rel="up">ntp-keygen Invocation</a> </p> 1981 </div> 1982 <a name="ntp_002dkeygen-Bugs-1"></a> 1983 <h4 class="subsection">1.2.26 ntp-keygen Bugs</h4> 1984 1985 <hr> 1986 <a name="Random-Seed-File"></a> 1987 <div class="header"> 1988 <p> 1989 Next: <a href="#Cryptographic-Data-Files" accesskey="n" rel="next">Cryptographic Data Files</a>, Previous: <a href="#Running-the-Program" accesskey="p" rel="prev">Running the Program</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> </p> 1990 </div> 1991 <a name="Random-Seed-File-2"></a> 1992 <h3 class="section">1.3 Random Seed File</h3> 1993 1994 <p>All cryptographically sound key generation schemes must have means to 1995 randomize the entropy seed used to initialize the internal 1996 pseudo-random number generator used by the OpenSSL library routines. 1997 If a site supports ssh, it is very likely that means to do this are 1998 already available. 1999 The entropy seed used by the OpenSSL library is contained in a file, 2000 usually called <code>.rnd</code>, which must be available when 2001 starting the <code>ntp-keygen</code> program or <code>ntpd</code> daemon. 2002 </p> 2003 <p>The OpenSSL library looks for the file using the path specified by the 2004 <code>RANDFILE</code> environment variable in the user home directory, whether root 2005 or some other user. 2006 If the <code>RANDFILE</code> environment variable is not 2007 present, the library looks for the <code>.rnd</code> file in the user home 2008 directory. 2009 Since both the <code>ntp-keygen</code> program and <code>ntpd</code> daemon must run 2010 as root, the logical place to put this file is in <code>/.rnd</code> or 2011 <code>/root/.rnd</code>. 2012 If the file is not available or cannot be written, the program exits 2013 with a message to the system log. 2014 </p> 2015 <hr> 2016 <a name="Cryptographic-Data-Files"></a> 2017 <div class="header"> 2018 <p> 2019 Previous: <a href="#Random-Seed-File" accesskey="p" rel="prev">Random Seed File</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> </p> 2020 </div> 2021 <a name="Cryptographic-Data-Files-2"></a> 2022 <h3 class="section">1.4 Cryptographic Data Files</h3> 2023 2024 <p>File and link names are in the <code>form ntpkey_key_name.fstamp</code>, 2025 where <code>key</code> is the key or parameter type, 2026 <code>name</code> is the host or group name and 2027 <code>fstamp</code> is the filestamp (NTP seconds) when the file was created). 2028 By convention, key names in generated file names include both upper and 2029 lower case characters, while key names in generated link names include 2030 only lower case characters. The filestamp is not used in generated link 2031 names. 2032 </p> 2033 <p>The key name is a string defining the cryptographic key type. 2034 Key types include public/private keys host and sign, certificate cert 2035 and several challenge/response key types. 2036 By convention, client files used for 2037 challenges have a par subtype, as in the IFF challenge IFFpar, while 2038 server files for responses have a key subtype, as in the GQ response 2039 GQkey. 2040 </p> 2041 <p>All files begin with two nonencrypted lines. The first line contains 2042 the file name in the format <code>ntpkey_key_host.fstamp</code>. 2043 The second line contains the datestamp in conventional Unix date format. 2044 Lines beginning with <code>#</code> are ignored. 2045 </p> 2046 <p>The remainder of the file contains cryptographic data encoded first 2047 using ASN.1 rules, then encrypted using the DES-CBC algorithm with 2048 given password and finally written in PEM-encoded printable ASCII text 2049 preceded and followed by MIME content identifier lines. 2050 </p> 2051 <p>The format of the symmetric keys file, ordinarily named <code>ntp.keys</code>, 2052 is somewhat different than the other files in the interest of backward 2053 compatibility. 2054 Ordinarily, the file is generated by this program, but 2055 it can be constructed and edited using an ordinary text editor. 2056 </p> 2057 <div class="example"> 2058 <pre class="example"># ntpkey_MD5key_hms.local.3564038757 2059 # Sun Dec 9 02:45:57 2012 2060 2061 1 MD5 "]!ghT%O;3)WJ,/Nc:>I # MD5 key 2062 2 MD5 lu+H^tF46BKR-6~pV_5 # MD5 key 2063 3 MD5 :lnoVsE%Yz*avh%EtNC # MD5 key 2064 4 MD5 |fdZrf0sF~;w-i^V # MD5 key 2065 5 MD5 IyAG>O"y"LmCRS!*bHC # MD5 key 2066 6 MD5 ">e\A>hT/661ri52,,H # MD5 key 2067 7 MD5 c9x=M'CfLxax9v)PV-si # MD5 key 2068 8 MD5 E|=jvFVov?Bn|Ev=&aK\ # MD5 key 2069 9 MD5 T!c4UT&`(m$+m+B6,`Q0 # MD5 key 2070 10 MD5 JVF/1=)=IFbHbJQz..Cd # MD5 key 2071 11 SHA1 6dea311109529e436c2b4fccae9bc753c16d1b48 # SHA1 key 2072 12 SHA1 7076f373d86c4848c59ff8046e49cb7d614ec394 # SHA1 key 2073 13 SHA1 5f48b1b60591eb01b7cf1d33b7774f08d20262d3 # SHA1 key 2074 14 SHA1 eed5ab9d9497319ec60cf3781d52607e76720178 # SHA1 key 2075 15 SHA1 f283562611a04c964da8126296f5f8e58c3f85de # SHA1 key 2076 16 SHA1 1930da171297dd63549af50b29449de17dcf341f # SHA1 key 2077 17 SHA1 fee892110358cd4382322b889869e750db8e8a8f # SHA1 key 2078 18 SHA1 b5520c9fadd7ad3fd8bfa061c8821b65d029bb37 # SHA1 key 2079 19 SHA1 8c74fb440ec80f453ec6aaa62b9baed0ab723b92 # SHA1 key 2080 20 SHA1 6bc05f734306a189326000970c19b3910f403795 # SHA1 key 2081 </pre></div> 2082 2083 <p>Figure 1. Typical Symmetric Key File 2084 </p> 2085 <p>Figure 1 shows a typical symmetric keys file used by the reference 2086 implementation. 2087 Each line of the file contains three fields, first an 2088 integer between 1 and 65535, inclusive, representing the key identifier 2089 used in the server and peer configuration commands. 2090 Next is the key type for the message digest algorithm, 2091 which in the absence of the 2092 OpenSSL library must be MD5 to designate the MD5 message digest 2093 algorithm. 2094 If the OpenSSL library is installed, the key type can be any 2095 message digest algorithm supported by that library. 2096 However, if 2097 compatibility with FIPS 140-2 is required, the key type must be either 2098 SHA or SHA1. 2099 The key type can be changed using an ASCII text editor. 2100 </p> 2101 <p>An MD5 key consists of a printable ASCII string less than or equal to 2102 16 characters and terminated by whitespace or a # character. 2103 An OpenSSL 2104 key consists of a hex-encoded ASCII string of 40 characters, which is 2105 truncated as necessary. 2106 </p> 2107 <p>Note that the keys used by the <code>ntpq</code> and <code>ntpdc</code> programs are 2108 checked against passwords requested by the programs and entered by hand, 2109 so it 2110 is generally appropriate to specify these keys in human readable ASCII 2111 format. 2112 </p> 2113 <p>The <code>ntp-keygen</code> program generates a MD5 symmetric keys file 2114 <code>ntpkey_MD5key_hostname.filestamp</code>. 2115 Since the file contains private 2116 shared keys, it should be visible only to root and distributed by 2117 secure means to other subnet hosts. 2118 The NTP daemon loads the file <code>ntp.keys</code>, so <code>ntp-keygen</code> 2119 installs a soft link from this name to the generated file. 2120 Subsequently, similar soft links must be installed by 2121 manual or automated means on the other subnet hosts. 2122 While this file is 2123 not used with the Autokey Version 2 protocol, it is needed to 2124 authenticate some remote configuration commands used by the <code>ntpq</code> and 2125 <code>ntpdc</code> utilities. 2126 </p><hr> 2127 2128 2129 2130 </body> 2131 </html> 2132
Indexes created Wed Aug 26 00:26:28 UTC 2026