tor-browser

index.rst (16841B)

---

.. _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/>`__