ssltap-manual.html (5653B)
1 <HTML> 2 <!-- This Source Code Form is subject to the terms of the Mozilla Public 3 - License, v. 2.0. If a copy of the MPL was not distributed with this 4 - file, You can obtain one at http://mozilla.org/MPL/2.0/. --> 5 <HEAD> 6 <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> 7 <META NAME="GENERATOR" CONTENT="Mozilla/4.05 [en] (WinNT; U) [Netscape]"> 8 <META NAME="Author" CONTENT="Steve Parkinson"> 9 <TITLE>SSLTap - manual</TITLE> 10 </HEAD> 11 <BODY> 12 13 <H1> 14 SSLTap Manual page</H1> 15 16 <H3> 17 Summary</H3> 18 A command-line proxy which is SSL-aware. It snoops on TCP connections, 19 and displays the data going by, including SSL records and handshaking 20 if the connection is SSL. 21 <H3> 22 Synopsis</H3> 23 <TT>ssltap [-vhfsxl] [-p port] hostname:port</TT> 24 25 <P><TT> -v [prints version string]</TT> 26 <BR><TT> -h [outputs hex instead 27 of ASCII]</TT> 28 <BR><TT> -f [turn on Fancy HTML 29 coloring]</TT> 30 <BR><TT> -s [turn on SSL decoding]</TT> 31 <BR><TT> -x [turn on extra SSL 32 hex dumps]</TT> 33 <BR><TT> -p port [specify rendezvous port (default 1924)]</TT> 34 <BR><TT> -l [loop - continue 35 to wait for more connections]</TT> 36 <H3> 37 Description</H3> 38 SSLTap opens a socket on a rendezvous port, and waits for an incoming connection 39 (client side). Once this connection arrives, SSLTap makes another connection 40 to hostname:port (server side). It passes any data sent by the client to 41 the server, and vice versa. However, SSLTap will also display the data 42 to the console. It can do this for plain HTTP connections, or any TCP protocol. 43 However, SSLTap can also work with SSL streams, as detailed below. 44 45 <P>Let's assume your development machine is called 'intercept'. The simplest 46 usage of SSLTap is to run the command <TT>'ssltap www.netscape.com:80'</TT> 47 on intercept. The program will wait for an incoming connection on port 48 1924. Next you would want to go to your browser, and enter the URL http://intercept:1924. 49 The page retrieved by the browser will actually be gotten from the server 50 at www.netscape.com, but will go via SSLTap. 51 52 <P>Data sent from the client to the server is surrounded by a '--> [ ]' 53 symbol, and data sent from the server to the client, a '<---[ 54 ]' symbol. 55 56 <P>You'll notice that the page retrieved with this example looks incomplete. 57 This is because SSLTap by default closes down after the first connection 58 is complete, so the browser is not able to load images. To make the SSLTap 59 continue to accept connections, switch on looping mode with the -l option. 60 61 <P>You can change the default rendezvous port to something else with the 62 -p option. 63 64 <P>The remaining options change the way the output is produced. 65 66 <P>The -f option prints 'fancy' output - in colored HTML. Data sent from 67 the client to the server is in blue. The server's reply is in red. This 68 is designed so you can load the output up into a browser. When used with 69 looping mode, the different connections are separated with horizontal lines. 70 71 <P>-x will turn on HEX printing. Instead of being output as ascii, the 72 data is shown as Hex, like this: 73 <UL><TT><-- [</TT> 74 <BR><TT> 0: 56 d5 16 3e a1 6b b1 4a 8f 67 c4 d7 75 21 2f 6f dd | V..>.k.J.g..!/o.</TT> 76 <BR><TT> 10: bb 22 c4 75 8c f4 ce 28 16 a6 20 aa 77 fb 9a 59 a1 | .".u...(.. ...Y.</TT> 78 <BR><TT> 20: 51 91 14 d2 fc 9f a7 ea 4d 9c f7 3a 79 9d 83 62 4a | Q.......M..:..bJ</TT> 80 <BR><TT>]</TT> 81 <BR> </UL> 82 83 <H4> 84 SSL Parse mode</H4> 85 The following options deal with SSL connections. 86 <UL>-s will turn on SSL parsing. (SSLTap doesn't automatically detect SSL 87 sessions.) 88 <BR>-x will turn on extra SSL hexdumps. Mostly, if SSL can decode the data, 89 it doesn't display the hex.</UL> 90 The following SSL3 Data structures are parsed: Handshake, ClientHello, 91 ServerHello, CertificateChain, Certificate. In addition, SSL2 ClientHello, 92 ServerHello, ClientMasterKey are also partly parsed. NO DECRYPTION IS PERFORMED 93 ON THE DATA. SSLTAP CANNOT DECRYPT the data. 94 95 <P>If a certificate chain is detected, DER-encoded certificates will be 96 saved into files in the current directory called 'cert.0x' where x is the 97 sequence number of the certificate. 98 <BR> 99 <H3> 100 Operation Hints</H3> 101 Often, you'll find that the server certificate does not get transferred, 102 or other parts of the handshake do not happen. This is because the browser 103 is taking advantage of session-id-reuse (using the handshake results from 104 a previous session). If you restart the browser, it'll clear the session 105 id cache. 106 107 <P>If you run the ssltap on a different machine that the ssl server you're 108 trying to connect to, the browser will complain that the host name you're 109 trying to connect to is different to the certificate, but it will still 110 let you connect, after showing you a dialog. 111 <H3> 112 Bugs</H3> 113 Please contact <A HREF="mailto:ssltap-support@netscape.com">ssltap-support@netscape.com</A> 114 for bug reports. 115 <H3> 116 History</H3> 117 2.1 - First public release (March 1998) 118 <BR> 119 <H3> 120 Other</H3> 121 For reference, here is a table of some well-known port numbers: 122 <BR> 123 <TABLE BORDER=2 > 124 <TR> 125 <TD>HTTP</TD> 126 127 <TD>80</TD> 128 </TR> 129 130 <TR> 131 <TD>SMTP</TD> 132 133 <TD>25</TD> 134 </TR> 135 136 <TR> 137 <TD>HTTPS</TD> 138 139 <TD>443</TD> 140 </TR> 141 142 <TR> 143 <TD>FTP</TD> 144 145 <TD>21</TD> 146 </TR> 147 148 <TR> 149 <TD>IMAPS</TD> 150 151 <TD>993</TD> 152 </TR> 153 154 <TR> 155 <TD>NNTP</TD> 156 157 <TD>119</TD> 158 </TR> 159 160 <TR> 161 <TD>NNTPS</TD> 162 163 <TD>563</TD> 164 </TR> 165 </TABLE> 166 167 168 <P> 169 </BODY> 170 </HTML>