19c2daa00SOllivier Robert<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 29c2daa00SOllivier Robert<html> 39c2daa00SOllivier Robert <head> 4ea906c41SOllivier Robert <meta http-equiv="content-type" content="text/html;charset=iso-8859-1"> 59c2daa00SOllivier Robert <meta name="generator" content="HTML Tidy, see www.w3.org"> 69c2daa00SOllivier Robert <title>ntp-keygen - generate public and private keys</title> 79c2daa00SOllivier Robert <link href="scripts/style.css" type="text/css" rel="stylesheet"> 89c2daa00SOllivier Robert </head> 99c2daa00SOllivier Robert <body> 109c2daa00SOllivier Robert <h3><tt>ntp-keygen</tt> - generate public and private keys</h3> 112b15cb3dSCy Schubert <p><img src="pic/alice23.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/%7emills/pictures.html">from <i>Alice's Adventures in Wonderland</i>, Lewis Carroll</a></p> 129c2daa00SOllivier Robert <p>Alice holds the key.</p> 132b15cb3dSCy Schubert <p>Last update: 14*4e1ef62aSXin LI <!-- #BeginDate format:En2m -->24-Jul-2018 07:27<!-- #EndDate --> 152b15cb3dSCy Schubert UTC</p> 169c2daa00SOllivier Robert <br clear="left"> 179c2daa00SOllivier Robert <h4>Related Links</h4> 182b15cb3dSCy Schubert <script type="text/javascript" language="javascript" src="scripts/manual.txt"></script> 199c2daa00SOllivier Robert <h4>Table of Contents</h4> 209c2daa00SOllivier Robert <ul> 212b15cb3dSCy Schubert <li class="inline"><a href="#synop">Synopsis</a></li> 222b15cb3dSCy Schubert <li class="inline"><a href="#descrip">Description</a></li> 232b15cb3dSCy Schubert <li class="inline"><a href="#run">Running the program</a></li> 242b15cb3dSCy Schubert <li class="inline"><a href="#cmd">Command Line Options</a></li> 252b15cb3dSCy Schubert <li class="inline"><a href="#rand">Random Seed File</a></li> 262b15cb3dSCy Schubert <li class="inline"><a href="#fmt">Cryptographic Data Files</a></li> 272b15cb3dSCy Schubert <li class="inline"><a href="#bug">Bugs</a></li> 289c2daa00SOllivier Robert </ul> 299c2daa00SOllivier Robert <hr> 309c2daa00SOllivier Robert <h4 id="synop">Synopsis</h4> 312b15cb3dSCy Schubert <p id="intro"><tt>ntp-keygen [ -deGHIMPT ] [ -b <i>modulus</i> ] [ -c [ RSA-MD2 | RSA-MD5 | RSA-SHA 322b15cb3dSCy Schubert | RSA-SHA1 | RSA-MDC2 | RSA-RIPEMD160 | DSA-SHA | DSA-SHA1 ] ] 332b15cb3dSCy Schubert [ -C <i>cipher</i> ] [-i <i>group</i> ] [ -l <em>days</em>] 342b15cb3dSCy Schubert [ -m <i>modulus</i> ] [ -p <i>passwd1</i> ] [ -q <i>passwd2</i> ] 352b15cb3dSCy Schubert [ -S [ RSA | DSA ] ] [ -s <i>host</i> ] [ -V <i>nkeys</i> ]</tt></p> 369c2daa00SOllivier Robert <h4 id="descrip">Description</h4> 3709100258SXin LI <p>This program generates cryptographic data files used by the NTPv4 3809100258SXin LI authentication and identity schemes. It can generate message digest keys 3909100258SXin LI used in symmetric key cryptography and, if the OpenSSL software library 4009100258SXin LI has been installed, it can generate host keys, sign keys, certificates, 4109100258SXin LI and identity keys and parameters used by the Autokey public key 4209100258SXin LI cryptography. The message digest keys file is generated in a format 4309100258SXin LI compatible with NTPv3. All other files are in PEM-encoded printable ASCII 4409100258SXin LI format so they can be embedded as MIME attachments in mail to other 4509100258SXin LI sites.</p> 4609100258SXin LI <p>When used to generate message digest keys, the program produces a file 4709100258SXin LI containing ten pseudo-random printable ASCII strings suitable for the MD5 4809100258SXin LI message digest algorithm included in the distribution. If the OpenSSL 4909100258SXin LI library is installed, it produces an additional ten hex-encoded random bit 5009100258SXin LI strings suitable for the SHA1, AES-128 CMAC, and other message digest 5109100258SXin LI algorithms. The message digest keys file must be distributed and stored 5209100258SXin LI using secure means beyond the scope of NTP itself. Besides the keys used 5309100258SXin LI for ordinary NTP associations, additional keys can be defined as passwords 5409100258SXin LI for the <tt><a href="ntpq.html">ntpq</a></tt> 5509100258SXin LI and <tt><a href="ntpdc.html">ntpdc</a></tt> utility programs.</p> 5609100258SXin LI <p>The remaining generated files are compatible with other OpenSSL 5709100258SXin LI applications and other Public Key Infrastructure (PKI) 5809100258SXin LI resources. Certificates generated by this program are compatible with 5909100258SXin LI extant industry practice, although some users might find the 6009100258SXin LI interpretation of X509v3 extension fields somewhat liberal. However, 6109100258SXin LI the identity keys are probably not compatible with anything other than 6209100258SXin LI Autokey.</p> 6309100258SXin LI <p>Some files used by this program are encrypted using a private 6409100258SXin LI password. The <tt>-p</tt> option specifies the password for local 6509100258SXin LI encrypted files and the <tt>-q</tt> option the password for encrypted 6609100258SXin LI files sent to remote sites. If no password is specified, the host name 6709100258SXin LI returned by the Unix <tt>gethostname()</tt> function, normally the DNS 6809100258SXin LI name of the host, is used.</p> 6909100258SXin LI <p>The <tt>pw</tt> option of the <tt>crypto</tt> configuration command 7009100258SXin LI specifies the read password for previously encrypted local files. 7109100258SXin LI This must match the local password used by this program. If not 7209100258SXin LI specified, the host name is used. Thus, if files are generated by 7309100258SXin LI this program without password, they can be read back by <tt>ntpd</tt> 7409100258SXin LI without password, but only on the same host.</p> 7509100258SXin LI <p>Normally, encrypted files for each host are generated by that host 7609100258SXin LI and used only by that host, although exceptions exist as noted later 7709100258SXin LI on this page. The symmetric keys file, normally 7809100258SXin LI called <tt>ntp.keys</tt>, is usually installed in <tt>/etc</tt>. 7909100258SXin LI Other files and links are usually installed 8009100258SXin LI in <tt>/usr/local/etc</tt>, which is normally in a shared filesystem 8109100258SXin LI in NFS-mounted networks and cannot be changed by shared clients. The 8209100258SXin LI location of the keys directory can be changed by the <tt>keysdir</tt> 8309100258SXin LI configuration command in such cases. Normally, this is 8409100258SXin LI in <tt>/etc</tt>.</p> 8509100258SXin LI <p>This program directs commentary and error messages to the standard 8609100258SXin LI error stream <tt>stderr</tt> and remote files to the standard output 8709100258SXin LI stream <tt>stdout</tt> where they can be piped to other applications 8809100258SXin LI or redirected to files. The names used for generated files and links 8909100258SXin LI all begin with the string <tt>ntpkey</tt> and include the file type, 9009100258SXin LI generating host and filestamp, as described in 9109100258SXin LI the <a href="#fmt">Cryptographic Data Files</a> section below</p> 922b15cb3dSCy Schubert <h4 id="run">Running the Program</h4> 9309100258SXin LI <p>To test and gain experience with Autokey concepts, log in as root and 9409100258SXin LI change to the keys directory, usually <tt>/usr/local/etc</tt>. When 9509100258SXin LI run for the first time, or if all files with names 9609100258SXin LI beginning <tt>ntpkey</tt> have been removed, use 9709100258SXin LI the <tt>ntp-keygen</tt> command without arguments to generate a 9809100258SXin LI default RSA host key and matching RSA-MD5 certificate with expiration 9909100258SXin LI date one year hence. If run again without options, the program uses 10009100258SXin LI the existing keys and parameters and generates only a new certificate 10109100258SXin LI with new expiration date one year hence.</p> 10209100258SXin LI <p>Run the command on as many hosts as necessary. Designate one of them 10309100258SXin LI as the trusted host (TH) using <tt>ntp-keygen</tt> with 10409100258SXin LI the <tt>-T</tt> option and configure it to synchronize from reliable 10509100258SXin LI Internet servers. Then configure the other hosts to synchronize to 10609100258SXin LI the TH directly or indirectly. A certificate trail is created when 10709100258SXin LI Autokey asks the immediately ascendant host towards the TH to sign its 10809100258SXin LI certificate, which is then provided to the immediately descendant host 10909100258SXin LI on request. All group hosts should have acyclic certificate trails 11009100258SXin LI ending on the TH.</p> 11109100258SXin LI <p>The host key is used to encrypt the cookie when required and so must 11209100258SXin LI be RSA type. By default, the host key is also the sign key used to 11309100258SXin LI encrypt signatures. A different sign key can be assigned using 11409100258SXin LI the <tt>-S</tt> option and this can be either RSA or DSA type. By 11509100258SXin LI default, the signature message digest type is MD5, but any combination 11609100258SXin LI of sign key type and message digest type supported by the OpenSSL 11709100258SXin LI library can be specified using the <tt>-c</tt> option.</p> 11809100258SXin LI <p>The rules say cryptographic media should be generated with proventic 11909100258SXin LI filestamps, which means the host should already be synchronized before 12009100258SXin LI this program is run. This of course creates a chicken-and-egg problem 12109100258SXin LI when the host is started for the first time. Accordingly, the host 12209100258SXin LI time should be set by some other means, such as 12309100258SXin LI eyeball-and-wristwatch, at least so that the certificate lifetime is 12409100258SXin LI within the current year. After that and when the host is synchronized 12509100258SXin LI to a proventic source, the certificate should be re-generated.</p> 12609100258SXin LI <p>Additional information on trusted groups and identity schemes is on 12709100258SXin LI the <a href="autokey.html">Autokey Public-Key Authentication</a> 12809100258SXin LI page.</p> 1299c2daa00SOllivier Robert <h4 id="cmd">Command Line Options</h4> 1309c2daa00SOllivier Robert <dl> 1312b15cb3dSCy Schubert <dt><tt>-b <i>modulus</i></tt></dt> 13209100258SXin LI <dd>Set the modulus for generating identity keys to <i>modulus</i> 13309100258SXin LI bits. The modulus defaults to 256, but can be set from 256 (32 13409100258SXin LI octets) to 2048 (256 octets). Use the larger moduli with caution, 13509100258SXin LI as this can consume considerable computing resources and increases 13609100258SXin LI the size of authenticated packets.</dd> 1372b15cb3dSCy Schubert <dt><tt>-c [ RSA-MD2 | RSA-MD5 | RSA-SHA | RSA-SHA1 | RSA-MDC2 | RSA-RIPEMD160 | DSA-SHA | DSA-SHA1 ]</tt></dt> 13809100258SXin LI <dd>Select certificate digital signature and message digest scheme. 13909100258SXin LI Note that RSA schemes must be used with an RSA sign key and DSA 14009100258SXin LI schemes must be used with a DSA sign key. The default without this 14109100258SXin LI option is <tt>RSA-MD5</tt>. If compatibility with FIPS 140-2 is 14209100258SXin LI required, either the <tt>DSA-SHA</tt> or <tt>DSA-SHA1</tt> scheme 14309100258SXin LI must be used.</dd> 1442b15cb3dSCy Schubert <dt><tt>-C <i>cipher</i></tt></dt> 14509100258SXin LI <dd>Select the OpenSSL cipher to use for password-protected keys. 14609100258SXin LI The <tt>openssl -h</tt> command provided with OpenSSL displays 14709100258SXin LI available ciphers. The default without this option 14809100258SXin LI is <tt>des-ede3-cbc</tt>.</dd> 1492b15cb3dSCy Schubert <dt><tt>-d</tt></dt> 15009100258SXin LI <dd>Enable debugging. This option displays the cryptographic data 15109100258SXin LI produced for eye-friendly billboards.</dd> 1522b15cb3dSCy Schubert <dt><tt>-e</tt></dt> 15309100258SXin LI <dd>Extract the IFF or GQ public parameters from the <tt>IFFkey</tt> 15409100258SXin LI or <tt>GQkey</tt> keys file previously specified. Send the 15509100258SXin LI unencrypted data to the standard output stream <tt>stdout</tt>.</dd> 1562b15cb3dSCy Schubert <dt><tt>-G</tt></dt> 15709100258SXin LI <dd>Generate a new encrypted GQ key file for the Guillou-Quisquater 15809100258SXin LI (GQ) identity scheme. This option is mutually exclusive with 15909100258SXin LI the <tt>-I</tt> and <tt>-V</tt> options.</dd> 1602b15cb3dSCy Schubert <dt><tt>-H</tt></dt> 1612b15cb3dSCy Schubert <dd>Generate a new encrypted RSA public/private host key file.</dd> 1622b15cb3dSCy Schubert <dt><tt>-i <i>group</i></tt></dt> 16309100258SXin LI <dd>Set the optional Autokey group name to <tt><i>group</i></tt>. This 16409100258SXin LI is used in the identity scheme parameter file names. In that role, 16509100258SXin LI the default is the host name if no group is provided. The group 16609100258SXin LI name, if specified using <tt>-i</tt> or using <tt>-s</tt> following 16709100258SXin LI an <tt>@</tt> character, is also used in certificate subject and 16809100258SXin LI issuer names in the form <tt><i>host</i>@<i>group</i></tt> and 16909100258SXin LI should match the group specified via <tt>crypto ident</tt> 17009100258SXin LI or <tt>server ident</tt> in ntpd's configuration file.</dd> 1712b15cb3dSCy Schubert <dt><tt>-I</tt></dt> 17209100258SXin LI <dd>Generate a new encrypted IFF key file for the Schnorr (IFF) 17309100258SXin LI identity scheme. This option is mutually exclusive with 17409100258SXin LI the <tt>-G</tt> and <tt>-V</tt> options.</dd> 1752b15cb3dSCy Schubert <dt><tt>-l <i>days</i></tt></dt> 17609100258SXin LI <dd>Set the lifetime for certificates to <tt><i>days</i></tt>. The 17709100258SXin LI default lifetime is one year (365 d).</dd> 1782b15cb3dSCy Schubert <dt><tt>-m <i>modulus</i></tt></dt> 17909100258SXin LI <dd>Set the modulus for generating files to <i>modulus</i> bits. The 18009100258SXin LI modulus defaults to 512, but can be set from 256 (32 octets) to 2048 18109100258SXin LI (256 octets). Use the larger moduli with caution, as this can 18209100258SXin LI consume considerable computing resources and increases the size of 18309100258SXin LI authenticated packets.</dd> 1842b15cb3dSCy Schubert <dt><tt>-M</tt></dt> 18509100258SXin LI <dd>Generate a new keys file containing 10 MD5 keys and 10 SHA keys. 18609100258SXin LI An MD5 key is a string of 20 random printable ASCII characters, 18709100258SXin LI while a SHA key is a string of 40 random hex digits. The file can be 18809100258SXin LI edited using a text editor to change the key type or key content. 18909100258SXin LI This option is mutually exclusive with all other options.</dd> 1902b15cb3dSCy Schubert <dt><tt>-P</tt></dt> 19109100258SXin LI <dd>Generate a new private certificate used by the PC identity scheme. 19209100258SXin LI By default, the program generates public certificates. Note: the PC 19309100258SXin LI identity scheme is not recommended for new installations.</dd> 1942b15cb3dSCy Schubert <dt><tt>-p <i>passwd</i></tt></dt> 19509100258SXin LI <dd>Set the password for reading and writing encrypted files 19609100258SXin LI to <tt><i>passwd</i></tt>. These include the host, sign and 19709100258SXin LI identify key files. By default, the password is the string returned 19809100258SXin LI by the Unix <tt>gethostname()</tt> routine.</dd> 1992b15cb3dSCy Schubert <dt><tt>-q <i>passwd</i></tt></dt> 20009100258SXin LI <dd>Set the password for writing encrypted IFF, GQ and MV identity 20109100258SXin LI files redirected to <tt>stdout</tt> to <tt><i>passwd</i></tt>=. In 20209100258SXin LI effect, these files are decrypted with the <tt>-p</tt> password, 20309100258SXin LI then encrypted with the <tt>-q</tt> password. By default, the 20409100258SXin LI password is the string returned by the Unix <tt>gethostname()</tt> 20509100258SXin LI routine.</dd> 2062b15cb3dSCy Schubert <dt><tt>-S [ RSA | DSA ]</tt></dt> 20709100258SXin LI <dd>Generate a new encrypted public/private sign key file of the 20809100258SXin LI specified type. By default, the sign key is the host key and has 20909100258SXin LI the same type. If compatibly with FIPS 140-2 is required, the sign 21009100258SXin LI key type must be <tt>DSA</tt>.</dd> 2112b15cb3dSCy Schubert <dt><tt>-s <i>host</i>[@<i>group</i>]</tt></dt> 21209100258SXin LI <dd>Specify the Autokey host name, where <tt><i>host</i></tt> is the 21309100258SXin LI host name and <tt><i>group</i></tt> is the optional group name. The 21409100258SXin LI host name, and if provided, group name are used 21509100258SXin LI in <tt><i>host</i>@<i>group</i></tt> form as certificate subject and 21609100258SXin LI issuer. Specifying <tt>-s @<i>group</i></tt> is allowed, and 21709100258SXin LI results in leaving the host name unchanged, as 21809100258SXin LI with <tt>-i <i>group</i></tt>. The group name, or if no group is 21909100258SXin LI provided, the host name are also used in the file names of IFF, GQ, 22009100258SXin LI and MV identity scheme parameter files. If <tt><i>host</i></tt> is 22109100258SXin LI not specified, the default host name is the string returned by 22209100258SXin LI the <tt>gethostname()</tt> routine.</dd> 2232b15cb3dSCy Schubert <dt><tt>-T</tt></dt> 22409100258SXin LI <dd>Generate a trusted certificate. By default, the program generates 22509100258SXin LI nontrusted certificates.</dd> 2262b15cb3dSCy Schubert <dt><tt>-V <i>nkeys</i></tt></dt> 22709100258SXin LI <dd>Generate <tt>nkeys</tt> encrypted server keys for the 22809100258SXin LI Mu-Varadharajan (MV) identity scheme. This option is mutually 22909100258SXin LI exclusive with the <tt>-I</tt> and <tt>-G</tt> options. Note: 23009100258SXin LI support for this option should be considered a work in 23109100258SXin LI progress.</dd> 2329c2daa00SOllivier Robert </dl> 2339c2daa00SOllivier Robert <h4 id="rand">Random Seed File</h4> 23409100258SXin LI <p>All cryptographically sound key generation schemes must have means to 23509100258SXin LI randomize the entropy seed used to initialize the internal 23609100258SXin LI pseudo-random number generator used by the OpenSSL library routines. 23709100258SXin LI If a site supports <tt>ssh</tt>, it is very likely that means to do 23809100258SXin LI this are already available. The entropy seed used by the OpenSSL 23909100258SXin LI library is contained in a file, usually called <tt>.rnd</tt>, which 24009100258SXin LI must be available when starting the <tt>ntp-keygen</tt> program 24109100258SXin LI or <tt>ntpd</tt> daemon.</p> 24209100258SXin LI <p>The OpenSSL library looks for the file using the path specified by 24309100258SXin LI the <tt>RANDFILE</tt> environment variable in the user home directory, 24409100258SXin LI whether root or some other user. If the <tt>RANDFILE</tt> environment 24509100258SXin LI variable is not present, the library looks for the <tt>.rnd</tt> file 24609100258SXin LI in the user home directory. Since both the <tt>ntp-keygen</tt> 24709100258SXin LI program and <tt>ntpd</tt> daemon must run as root, the logical place 24809100258SXin LI to put this file is in <tt>/.rnd</tt> or <tt>/root/.rnd</tt>. If the 24909100258SXin LI file is not available or cannot be written, the program exits with a 25009100258SXin LI message to the system log.</p> 2512b15cb3dSCy Schubert <h4 id="fmt">Cryptographic Data Files</h4> 25209100258SXin LI <p>File and link names are in the 25309100258SXin LI form <tt>ntpkey_<i>key</i>_<i>name</i>.<i>fstamp</i></tt>, 25409100258SXin LI where <tt><i>key</i></tt> is the key or parameter 25509100258SXin LI type, <tt><i>name</i></tt> is the host or group name 25609100258SXin LI and <tt><i>fstamp</i></tt> is the filestamp (NTP seconds) when the 25709100258SXin LI file was created). By convention, <em><tt>key</tt></em> names in 25809100258SXin LI generated file names include both upper and lower case characters, 25909100258SXin LI while <em><tt>key</tt></em> names in generated link names include only 26009100258SXin LI lower case characters. The filestamp is not used in generated link 26109100258SXin LI names.</p> 26209100258SXin LI <p>The <em><tt>key</tt></em> name is a string defining the cryptographic 26309100258SXin LI key type. Key types include public/private keys <tt>host</tt> 26409100258SXin LI and <tt>sign</tt>, certificate <tt>cert</tt> and several 26509100258SXin LI challenge/response key types. By convention, client files used for 26609100258SXin LI challenges have a <tt>par</tt> subtype, as in the IFF 26709100258SXin LI challenge <tt>IFFpar</tt>, while server files for responses have 26809100258SXin LI a <tt>key</tt> subtype, as in the GQ response <tt>GQkey</tt>.</p> 26909100258SXin LI <p>All files begin with two nonencrypted lines. The first line contains 27009100258SXin LI the file name in the 27109100258SXin LI format <tt>ntpkey_<i>key</i>_<i>host</i>.<i>fstamp</i></tt>. The second 27209100258SXin LI line contains the datestamp in conventional Unix <tt>date</tt> format. 27309100258SXin LI Lines beginning with <tt>#</tt> are ignored.</p> 27409100258SXin LI <p>The remainder of the file contains cryptographic data encoded first 27509100258SXin LI using ASN.1 rules, then encrypted using the DES-CBC algorithm with 27609100258SXin LI given password and finally written in PEM-encoded printable ASCII text 27709100258SXin LI preceded and followed by MIME content identifier lines.</p> 27809100258SXin LI <p>The format of the symmetric keys file, ordinarily 27909100258SXin LI named <tt>ntp.keys,</tt> is somewhat different than the other files in 28009100258SXin LI the interest of backward compatibility. Ordinarily, the file is 28109100258SXin LI generated by this program, but it can be constructed and edited using 28209100258SXin LI an ordinary text editor.</p> 28309100258SXin LI <table> 28409100258SXin LI <caption style="caption-side: bottom;"> 28509100258SXin LI Figure 1. Typical Symmetric Key File 28609100258SXin LI </caption> 28709100258SXin LI <tr><td style="border: 1px solid black; border-spacing: 0;"> 28809100258SXin LI <pre style="color:grey;"> 28909100258SXin LI # ntpkey_MD5key_bk.ntp.org.3595864945 29009100258SXin LI # Thu Dec 12 19:22:25 2013 29109100258SXin LI 29209100258SXin LI 1 MD5 L";Nw<`.I<f4U0)247"i # MD5 key 29309100258SXin LI 2 MD5 &>l0%XXK9O'51VwV<xq~ # MD5 key 29409100258SXin LI 3 MD5 lb4zLW~d^!K:]RsD'qb6 # MD5 key 29509100258SXin LI 4 MD5 Yue:tL[+vR)M`n~bY,'? # MD5 key 29609100258SXin LI 5 MD5 B;fxlKgr/&4ZTbL6=RxA # MD5 key 29709100258SXin LI 6 MD5 4eYwa`o}3i@@V@..R9!l # MD5 key 29809100258SXin LI 7 MD5 `A.([h+;wTQ|xfi%Sn_! # MD5 key 29909100258SXin LI 8 MD5 45:V,r4]l6y^JH6.Sh?F # MD5 key 30009100258SXin LI 9 MD5 3-5vcn*6l29DS?Xdsg)* # MD5 key 30109100258SXin LI 10 MD5 2late4Me # MD5 key 30209100258SXin LI 11 SHA1 a27872d3030a9025b8446c751b4551a7629af65c # SHA1 key 30309100258SXin LI 12 SHA1 21bc3b4865dbb9e920902abdccb3e04ff97a5e74 # SHA1 key 30409100258SXin LI 13 SHA1 2b7736fe24fef5ba85ae11594132ab5d6f6daba9 # SHA1 key 30509100258SXin LI 14 SHA a5332809c8878dd3a5b918819108a111509aeceb # SHA key 30609100258SXin LI 15 MD2 2fe16c88c760ff2f16d4267e36c1aa6c926e6964 # MD2 key 30709100258SXin LI 16 MD4 b2691811dc19cfc0e2f9bcacd74213f29812183d # MD4 key 30809100258SXin LI 17 MD5 e4d6735b8bdad58ec5ffcb087300a17f7fef1f7c # MD5 key 30909100258SXin LI 18 MDC2 a8d5e2315c025bf3a79174c87fbd10477de2eabc # MDC2 key 31009100258SXin LI 19 RIPEMD160 77ca332cafb30e3cafb174dcd5b80ded7ba9b3d2 # RIPEMD160 key 31109100258SXin LI 20 AES128CMAC f92ff73eee86c1e7dc638d6489a04e4e555af878 # AES128CMAC key 31209100258SXin LI 21 MD5 sampo 10.1.2.3/24 31309100258SXin LI </pre></td></tr></table> 31409100258SXin LI <p>Figure 1 shows a typical symmetric keys file used by the reference 31509100258SXin LI implementation. Each line of the file contains three or four fields, 316*4e1ef62aSXin LI first an integer between 1 and 65535, inclusive, representing the key 31709100258SXin LI identifier used in the <tt>server</tt> and <tt>peer</tt> configuration 31809100258SXin LI commands. Second is the key type for the message digest algorithm, 31909100258SXin LI which in the absence of the OpenSSL library must be <tt>MD5</tt> to 32009100258SXin LI designate the MD5 message digest algorithm. If the OpenSSL library is 32109100258SXin LI installed, the key type can be any message digest algorithm supported 32209100258SXin LI by that library. However, if compatibility with FIPS 140-2 is 32309100258SXin LI required, the key type must be either <tt>SHA</tt> or <tt>SHA1</tt>. 32409100258SXin LI The key type can be changed using an ASCII text editor.</p> 32509100258SXin LI <p>The third field is the key.</p> 32609100258SXin LI <p>An MD5 key consists of a printable ASCII string less than or equal to 32709100258SXin LI 16 characters and terminated by whitespace or a # character. An 32809100258SXin LI OpenSSL key consists of a hex-encoded ASCII string of 40 characters, 32909100258SXin LI which is truncated as necessary.</p> 33009100258SXin LI <p>Note that the keys used by the <tt>ntpq</tt> and <tt>ntpdc</tt> 33109100258SXin LI programs are checked against passwords requested by the programs and 33209100258SXin LI entered by hand, so it is generally appropriate to specify these keys 33309100258SXin LI in human readable ASCII format.</p> 33409100258SXin LI <p>The optional fourth field is one or more IPs, with each IP separated 33509100258SXin LI with a comma. An IP may end with an optional <tt>/subnetbits</tt> 33609100258SXin LI suffix, which limits the acceptance of the key identifier to packets 33709100258SXin LI claiming to be from the described IP space.</p> 33809100258SXin LI <p>The <tt>ntp-keygen</tt> program generates a MD5 symmetric keys 33909100258SXin LI file <tt>ntpkey_MD5key_<i>hostname.filestamp</i></tt>. Since the file 34009100258SXin LI contains private shared keys, it should be visible only to root and 34109100258SXin LI distributed by secure means to other subnet hosts. The NTP daemon 34209100258SXin LI loads the file <tt>ntp.keys</tt>, so <tt>ntp-keygen</tt> installs a 34309100258SXin LI soft link from this name to the generated file. Subsequently, similar 34409100258SXin LI soft links must be installed by manual or automated means on the other 34509100258SXin LI subnet hosts. While this file is not used with the Autokey Version 2 34609100258SXin LI protocol, it is needed to authenticate some remote configuration 34709100258SXin LI commands used by the <a href="ntpq.html"><tt>ntpq</tt></a> 34809100258SXin LI and <a href="ntpdc.html"><tt>ntpdc</tt></a> utilities.</p> 3499c2daa00SOllivier Robert <h4 id="bug">Bugs</h4> 35009100258SXin LI <p>It can take quite a while to generate some cryptographic values.</p> 3519c2daa00SOllivier Robert <hr> 3529c2daa00SOllivier Robert <script type="text/javascript" language="javascript" src="scripts/footer.txt"></script> 3539c2daa00SOllivier Robert </body> 3549c2daa00SOllivier Robert</html> 355
