.. _mozilla_projects_nss_reference_nss_tools_:_ssltap:

NSS tools : ssltap
==================

.. container::

   Name

   ssltap — Tap into SSL connections and display the data going by

   Synopsis

   libssltap [-vhfsxl] [-p port] [hostname:port]

   Description

   | The SSL Debugging Tool ssltap is an SSL-aware command-line proxy. It
   | watches TCP connections and displays the data going by. If a connection is
   | SSL, the data display includes interpreted SSL records and handshaking

   Options

   -v

   Print a version string for the tool.

   -h

   | Turn on hex/ASCII printing. Instead of outputting raw data, the
   | command interprets each record as a numbered line of hex values,
   | followed by the same data as ASCII characters. The two parts are
   | separated by a vertical bar. Nonprinting characters are replaced
   | by dots.

   -f

   | Turn on fancy printing. Output is printed in colored HTML. Data
   | sent from the client to the server is in blue; the server's reply
   | is in red. When used with looping mode, the different connections
   | are separated with horizontal lines. You can use this option to
   | upload the output into a browser.

   -s

   | Turn on SSL parsing and decoding. The tool does not automatically
   | detect SSL sessions. If you are intercepting an SSL connection,
   | use this option so that the tool can detect and decode SSL
   | structures.

   | If the tool detects a certificate chain, it saves the DER-encoded
   | certificates into files in the current directory. The files are
   | named cert.0x, where x is the sequence number of the certificate.

   | If the -s option is used with -h, two separate parts are printed
   | for each record: the plain hex/ASCII output, and the parsed SSL
   | output.

   -x

   | Turn on hex/ASCII printing of undecoded data inside parsed SSL
   | records. Used only with the -s option. This option uses the same
   | output format as the -h option.

   -l prefix

   | Turn on looping; that is, continue to accept connections rather
   | than stopping after the first connection is complete.

   -p port

   Change the default rendezvous port (1924) to another port.

   The following are well-known port numbers:

   \* HTTP 80

   \* HTTPS 443

   \* SMTP 25

   \* FTP 21

   \* IMAP 143

   \* IMAPS 993 (IMAP over SSL)

   \* NNTP 119

   \* NNTPS 563 (NNTP over SSL)

   Usage and Examples

   | You can use the SSL Debugging Tool to intercept any connection
   | information. Although you can run the tool at its most basic by issuing
   | the ssltap command with no options other than hostname:port, the
   | information you get in this way is not very useful. For example, assume
   | your development machine is called intercept. The simplest way to use the
   | debugging tool is to execute the following command from a command shell:

   $ ssltap www.netscape.com

   | The program waits for an incoming connection on the default port 1924. In
   | your browser window, enter the URL http://intercept:1924. The browser
   | retrieves the requested page from the server at www.netscape.com, but the
   | page is intercepted and passed on to the browser by the debugging tool on
   | intercept. On its way to the browser, the data is printed to the command
   | shell from which you issued the command. Data sent from the client to the
   | server is surrounded by the following symbols: --> [ data ] Data sent from
   | the server to the client is surrounded by the following symbols: "left
   | arrow"-- [ data ] The raw data stream is sent to standard output and is
   | not interpreted in any way. This can result in peculiar effects, such as
   | sounds, flashes, and even crashes of the command shell window. To output a
   | basic, printable interpretation of the data, use the -h option, or, if you
   | are looking at an SSL connection, the -s option. You will notice that the
   | page you retrieved looks incomplete in the browser. This is because, by
   | default, the tool closes down after the first connection is complete, so
   | the browser is not able to load images. To make the tool continue to
   | accept connections, switch on looping mode with the -l option. The
   | following examples show the output from commonly used combinations of
   | options.

   Example 1

   $ ssltap.exe -sx -p 444 interzone.mcom.com:443 > sx.txt

   Output

   | Connected to interzone.mcom.com:443
   | -->; [
   | alloclen = 66 bytes
   | [ssl2] ClientHelloV2 {
   | version = {0x03, 0x00}
   | cipher-specs-length = 39 (0x27)
   | sid-length = 0 (0x00)
   | challenge-length = 16 (0x10)
   | cipher-suites = {

   | (0x010080) SSL2/RSA/RC4-128/MD5
   | (0x020080) SSL2/RSA/RC4-40/MD5
   | (0x030080) SSL2/RSA/RC2CBC128/MD5
   | (0x040080) SSL2/RSA/RC2CBC40/MD5
   | (0x060040) SSL2/RSA/DES64CBC/MD5
   | (0x0700c0) SSL2/RSA/3DES192EDE-CBC/MD5
   | (0x000004) SSL3/RSA/RC4-128/MD5
   | (0x00ffe0) SSL3/RSA-FIPS/3DES192EDE-CBC/SHA
   | (0x00000a) SSL3/RSA/3DES192EDE-CBC/SHA
   | (0x00ffe1) SSL3/RSA-FIPS/DES64CBC/SHA
   | (0x000009) SSL3/RSA/DES64CBC/SHA
   | (0x000003) SSL3/RSA/RC4-40/MD5
   | (0x000006) SSL3/RSA/RC2CBC40/MD5
   | }
   | session-id = { }
   | challenge = { 0xec5d 0x8edb 0x37c9 0xb5c9 0x7b70 0x8fe9 0xd1d3

   | 0x2592 }
   | }
   | ]
   | <-- [
   | SSLRecord {
   | 0: 16 03 00 03 e5 \|.....
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 997 (0x3e5)
   | handshake {
   | 0: 02 00 00 46 \|...F
   | type = 2 (server_hello)
   | length = 70 (0x000046)
   | ServerHello {
   | server_version = {3, 0}
   | random = {...}
   | 0: 77 8c 6e 26 6c 0c ec c0 d9 58 4f 47 d3 2d 01 45 \|
   | wn&l.ì..XOG.-.E
   | 10: 5c 17 75 43 a7 4c 88 c7 88 64 3c 50 41 48 4f 7f \|

   | \\.uC§L.Ç.d<PAHO.
   | session ID = {
   | length = 32

   | contents = {..}
   | 0: 14 11 07 a8 2a 31 91 29 11 94 40 37 57 10 a7 32 \| ...¨*1.)..@7W.§2
   | 10: 56 6f 52 62 fe 3d b3 65 b1 e4 13 0f 52 a3 c8 f6 \| VoRbþ=³e±...R£È.
   | }
   | cipher_suite = (0x0003) SSL3/RSA/RC4-40/MD5
   | }
   | 0: 0b 00 02 c5 \|...Å
   | type = 11 (certificate)
   | length = 709 (0x0002c5)
   | CertificateChain {
   | chainlength = 706 (0x02c2)
   | Certificate {
   | size = 703 (0x02bf)
   | data = { saved in file 'cert.001' }
   | }
   | }
   | 0: 0c 00 00 ca \|....
   | type = 12 (server_key_exchange)
   | length = 202 (0x0000ca)
   | 0: 0e 00 00 00 \|....
   | type = 14 (server_hello_done)
   | length = 0 (0x000000)
   | }
   | }
   | ]
   | --> [
   | SSLRecord {
   | 0: 16 03 00 00 44 \|....D
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 68 (0x44)
   | handshake {
   | 0: 10 00 00 40 \|...@
   | type = 16 (client_key_exchange)
   | length = 64 (0x000040)
   | ClientKeyExchange {
   | message = {...}
   | }
   | }
   | }
   | ]
   | --> [
   | SSLRecord {
   | 0: 14 03 00 00 01 \|.....
   | type = 20 (change_cipher_spec)
   | version = { 3,0 }
   | length = 1 (0x1)
   | 0: 01 \|.
   | }
   | SSLRecord {
   | 0: 16 03 00 00 38 \|....8
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 56 (0x38)
   | < encrypted >

   | }
   | ]
   | <-- [
   | SSLRecord {
   | 0: 14 03 00 00 01 \|.....
   | type = 20 (change_cipher_spec)
   | version = { 3,0 }
   | length = 1 (0x1)
   | 0: 01 \|.
   | }
   | ]
   | <-- [
   | SSLRecord {
   | 0: 16 03 00 00 38 \|....8
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 56 (0x38)
   | < encrypted >

   | }
   | ]
   | --> [
   | SSLRecord {
   | 0: 17 03 00 01 1f \|.....
   | type = 23 (application_data)
   | version = { 3,0 }
   | length = 287 (0x11f)
   | < encrypted >
   | }
   | ]
   | <-- [
   | SSLRecord {
   | 0: 17 03 00 00 a0 \|....
   | type = 23 (application_data)
   | version = { 3,0 }
   | length = 160 (0xa0)
   | < encrypted >

   | }
   | ]
   | <-- [
   | SSLRecord {
   | 0: 17 03 00 00 df \|....ß
   | type = 23 (application_data)
   | version = { 3,0 }
   | length = 223 (0xdf)
   | < encrypted >

   | }
   | SSLRecord {
   | 0: 15 03 00 00 12 \|.....
   | type = 21 (alert)
   | version = { 3,0 }
   | length = 18 (0x12)
   | < encrypted >
   | }
   | ]
   | Server socket closed.

   Example 2

   | The -s option turns on SSL parsing. Because the -x option is not used in
   | this example, undecoded values are output as raw data. The output is
   | routed to a text file.

   $ ssltap -s -p 444 interzone.mcom.com:443 > s.txt

   Output

   | Connected to interzone.mcom.com:443
   | --> [
   | alloclen = 63 bytes
   | [ssl2] ClientHelloV2 {
   | version = {0x03, 0x00}
   | cipher-specs-length = 36 (0x24)
   | sid-length = 0 (0x00)
   | challenge-length = 16 (0x10)
   | cipher-suites = {
   | (0x010080) SSL2/RSA/RC4-128/MD5
   | (0x020080) SSL2/RSA/RC4-40/MD5
   | (0x030080) SSL2/RSA/RC2CBC128/MD5
   | (0x060040) SSL2/RSA/DES64CBC/MD5
   | (0x0700c0) SSL2/RSA/3DES192EDE-CBC/MD5
   | (0x000004) SSL3/RSA/RC4-128/MD5
   | (0x00ffe0) SSL3/RSA-FIPS/3DES192EDE-CBC/SHA
   | (0x00000a) SSL3/RSA/3DES192EDE-CBC/SHA
   | (0x00ffe1) SSL3/RSA-FIPS/DES64CBC/SHA
   | (0x000009) SSL3/RSA/DES64CBC/SHA
   | (0x000003) SSL3/RSA/RC4-40/MD5
   | }
   | session-id = { }
   | challenge = { 0x713c 0x9338 0x30e1 0xf8d6 0xb934 0x7351 0x200c
   | 0x3fd0 }
   | ]
   | >-- [
   | SSLRecord {
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 997 (0x3e5)
   | handshake {
   | type = 2 (server_hello)
   | length = 70 (0x000046)
   | ServerHello {
   | server_version = {3, 0}
   | random = {...}
   | session ID = {
   | length = 32
   | contents = {..}
   | }
   | cipher_suite = (0x0003) SSL3/RSA/RC4-40/MD5
   | }
   | type = 11 (certificate)
   | length = 709 (0x0002c5)
   | CertificateChain {
   | chainlength = 706 (0x02c2)
   | Certificate {
   | size = 703 (0x02bf)
   | data = { saved in file 'cert.001' }
   | }
   | }
   | type = 12 (server_key_exchange)
   | length = 202 (0x0000ca)
   | type = 14 (server_hello_done)
   | length = 0 (0x000000)
   | }
   | }
   | ]
   | --> [
   | SSLRecord {
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 68 (0x44)
   | handshake {
   | type = 16 (client_key_exchange)
   | length = 64 (0x000040)
   | ClientKeyExchange {
   | message = {...}
   | }
   | }
   | }
   | ]
   | --> [
   | SSLRecord {
   | type = 20 (change_cipher_spec)
   | version = { 3,0 }
   | length = 1 (0x1)
   | }
   | SSLRecord {
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 56 (0x38)
   | > encrypted >
   | }
   | ]
   | >-- [
   | SSLRecord {
   | type = 20 (change_cipher_spec)
   | version = { 3,0 }
   | length = 1 (0x1)
   | }
   | ]
   | >-- [
   | SSLRecord {
   | type = 22 (handshake)
   | version = { 3,0 }
   | length = 56 (0x38)
   | > encrypted >
   | }
   | ]
   | --> [
   | SSLRecord {
   | type = 23 (application_data)
   | version = { 3,0 }
   | length = 287 (0x11f)
   | > encrypted >
   | }
   | ]
   | [
   | SSLRecord {
   | type = 23 (application_data)
   | version = { 3,0 }
   | length = 160 (0xa0)
   | > encrypted >
   | }
   | ]
   | >-- [
   | SSLRecord {
   | type = 23 (application_data)
   | version = { 3,0 }
   | length = 223 (0xdf)
   | > encrypted >
   | }
   | SSLRecord {
   | type = 21 (alert)
   | version = { 3,0 }
   | length = 18 (0x12)
   | > encrypted >
   | }
   | ]
   | Server socket closed.

   Example 3

   | In this example, the -h option turns hex/ASCII format. There is no SSL
   | parsing or decoding. The output is routed to a text file.

   $ ssltap -h -p 444 interzone.mcom.com:443 > h.txt

   Output

   | Connected to interzone.mcom.com:443
   | --> [
   | 0: 80 40 01 03 00 00 27 00 00 00 10 01 00 80 02 00 \| .@....'.........
   | 10: 80 03 00 80 04 00 80 06 00 40 07 00 c0 00 00 04 \| .........@......
   | 20: 00 ff e0 00 00 0a 00 ff e1 00 00 09 00 00 03 00 \| ........á.......
   | 30: 00 06 9b fe 5b 56 96 49 1f 9f ca dd d5 ba b9 52 \| ..þ[V.I.\xd9 ...º¹R
   | 40: 6f 2d \|o-
   | ]
   | <-- [
   | 0: 16 03 00 03 e5 02 00 00 46 03 00 7f e5 0d 1b 1d \| ........F.......
   | 10: 68 7f 3a 79 60 d5 17 3c 1d 9c 96 b3 88 d2 69 3b \| h.:y`..<..³.Òi;
   | 20: 78 e2 4b 8b a6 52 12 4b 46 e8 c2 20 14 11 89 05 \| x.K.¦R.KFè. ...
   | 30: 4d 52 91 fd 93 e0 51 48 91 90 08 96 c1 b6 76 77 \| MR.ý..QH.....¶vw
   | 40: 2a f4 00 08 a1 06 61 a2 64 1f 2e 9b 00 03 00 0b \| \*ô..¡.a¢d......
   | 50: 00 02 c5 00 02 c2 00 02 bf 30 82 02 bb 30 82 02 \| ..Å......0...0..
   | 60: 24 a0 03 02 01 02 02 02 01 36 30 0d 06 09 2a 86 \| $ .......60...*.
   | 70: 48 86 f7 0d 01 01 04 05 00 30 77 31 0b 30 09 06 \| H.÷......0w1.0..
   | 80: 03 55 04 06 13 02 55 53 31 2c 30 2a 06 03 55 04 \| .U....US1,0*..U.
   | 90: 0a 13 23 4e 65 74 73 63 61 70 65 20 43 6f 6d 6d \| ..#Netscape Comm
   | a0: 75 6e 69 63 61 74 69 6f 6e 73 20 43 6f 72 70 6f \| unications Corpo
   | b0: 72 61 74 69 6f 6e 31 11 30 0f 06 03 55 04 0b 13 \| ration1.0...U...
   | c0: 08 48 61 72 64 63 6f 72 65 31 27 30 25 06 03 55 \| .Hardcore1'0%..U
   | d0: 04 03 13 1e 48 61 72 64 63 6f 72 65 20 43 65 72 \| ....Hardcore Cer
   | e0: 74 69 66 69 63 61 74 65 20 53 65 72 76 65 72 20 \| tificate Server
   | f0: 49 49 30 1e 17 0d 39 38 30 35 31 36 30 31 30 33 \| II0...9805160103
   | <additional data lines>
   | ]
   | <additional records in same format>
   | Server socket closed.

   Example 4

   | In this example, the -s option turns on SSL parsing, and the -h option
   | turns on hex/ASCII format. Both formats are shown for each record. The
   | output is routed to a text file.

   $ ssltap -hs -p 444 interzone.mcom.com:443 > hs.txt

   Output

   | Connected to interzone.mcom.com:443
   | --> [
   | 0: 80 3d 01 03 00 00 24 00 00 00 10 01 00 80 02 00 \| .=....$.........
   | 10: 80 03 00 80 04 00 80 06 00 40 07 00 c0 00 00 04 \| .........@......
   | 20: 00 ff e0 00 00 0a 00 ff e1 00 00 09 00 00 03 03 \| ........á.......
   | 30: 55 e6 e4 99 79 c7 d7 2c 86 78 96 5d b5 cf e9 \|U..yÇ\xb0 ,.x.]µÏé
   | alloclen = 63 bytes
   | [ssl2] ClientHelloV2 {
   | version = {0x03, 0x00}
   | cipher-specs-length = 36 (0x24)
   | sid-length = 0 (0x00)
   | challenge-length = 16 (0x10)
   | cipher-suites = {
   | (0x010080) SSL2/RSA/RC4-128/MD5
   | (0x020080) SSL2/RSA/RC4-40/MD5
   | (0x030080) SSL2/RSA/RC2CBC128/MD5
   | (0x040080) SSL2/RSA/RC2CBC40/MD5
   | (0x060040) SSL2/RSA/DES64CBC/MD5
   | (0x0700c0) SSL2/RSA/3DES192EDE-CBC/MD5
   | (0x000004) SSL3/RSA/RC4-128/MD5
   | (0x00ffe0) SSL3/RSA-FIPS/3DES192EDE-CBC/SHA
   | (0x00000a) SSL3/RSA/3DES192EDE-CBC/SHA
   | (0x00ffe1) SSL3/RSA-FIPS/DES64CBC/SHA
   | (0x000009) SSL3/RSA/DES64CBC/SHA
   | (0x000003) SSL3/RSA/RC4-40/MD5
   | }
   | session-id = { }
   | challenge = { 0x0355 0xe6e4 0x9979 0xc7d7 0x2c86 0x7896 0x5db

   | 0xcfe9 }
   | }
   | ]
   | <additional records in same formats>
   | Server socket closed.

   Usage Tips

   | When SSL restarts a previous session, it makes use of cached information
   | to do a partial handshake. If you wish to capture a full SSL handshake,
   | restart the browser to clear the session id cache.

   | If you run the tool on a machine other than the SSL server to which you
   | are trying to connect, the browser will complain that the host name you
   | are trying to connect to is different from the certificate. If you are
   | using the default BadCert callback, you can still connect through a
   | dialog. If you are not using the default BadCert callback, the one you
   | supply must allow for this possibility.

   See Also

   | The NSS Security Tools are also documented at
   | [1]\ `http://www.mozilla.org/projects/security/pki/nss/ <https://www.mozilla.org/projects/security/pki/nss/>`__.

   Additional Resources

   | NSS is maintained in conjunction with PKI and security-related projects
   | through Mozilla dn Fedora. The most closely-related project is Dogtag PKI,
   | with a project wiki at [2]\ http://pki.fedoraproject.org/wiki/.

   | For information specifically about NSS, the NSS project wiki is located at
   | [3]\ `http://www.mozilla.org/projects/security/pki/nss/ <https://www.mozilla.org/projects/security/pki/nss/>`__.
     The NSS site relates
   | directly to NSS code changes and releases.

   Mailing lists: pki-devel@redhat.com and pki-users@redhat.com

   IRC: Freenode at #dogtag-pki

   Authors

   | The NSS tools were written and maintained by developers with Netscape and
   | now with Red Hat and Sun.

   | Authors: Elio Maldonado <emaldona@redhat.com>, Deon Lackey
   | <dlackey@redhat.com>.

   Copyright

   (c) 2010, Red Hat, Inc. Licensed under the GNU Public License version 2.

   References

   | Visible links
   | 1.
     `http://www.mozilla.org/projects/secu.../pki/nss/tools <https://www.mozilla.org/projects/security/pki/nss/tools>`__
   | 2. http://pki.fedoraproject.org/wiki/
   | 3.
     `http://www.mozilla.org/projects/security/pki/nss/ <https://www.mozilla.org/projects/security/pki/nss/>`__