gnutls-cli-debug (1)

NAME

gnutls-cli-debug - GnuTLS debug client

SYNOPSIS

gnutls-cli-debug [-flags] [-flag [value]] [--option-name[[=| ]value]]

Operands and options may be intermixed. They will be reordered.

DESCRIPTION

TLS debug client. It sets up multiple TLS connections to a server and queries its capabilities. It was created to assist in debugging GnuTLS, but it might be useful to extract a TLS server's capabilities. It connects to a TLS server, performs tests and print the server's capabilities. If called with the `-v' parameter more checks will be performed. Can be used to check for servers with special needs or bugs.

OPTIONS

-d number, --debug=number

Enable debugging. This option takes an integer number as its argument. The value of number is constrained to being:

in the range 0 through 9999

Specifies the debug level.

-V, --verbose

More verbose output. This option may appear an unlimited number of times.

-p number, --port=number

The port to connect to. This option takes an integer number as its argument. The value of number is constrained to being:

in the range 0 through 65536

--app-proto

This is an alias for the --starttls-proto option.

--starttls-proto=string

The application protocol to be used to obtain the server's certificate (https, ftp, smtp, imap, ldap, xmpp).

Specify the application layer protocol for STARTTLS. If the protocol is supported, gnutls-cli will proceed to the TLS negotiation.

-h, --help

Display usage information and exit.

-!, --more-help

Pass the extended usage information through a pager.

-v [{v|c|n --version [{v|c|n}]}]

Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice.

EXAMPLES

$ gnutls-cli-debug localhost

GnuTLS debug client 3.5.0

Checking localhost:443

for SSL 3.0 (RFC6101) support... yes

whether we need to disable TLS 1.2... no

whether we need to disable TLS 1.1... no

whether we need to disable TLS 1.0... no

whether %NO_EXTENSIONS is required... no

whether %COMPAT is required... no

for TLS 1.0 (RFC2246) support... yes

for TLS 1.1 (RFC4346) support... yes

for TLS 1.2 (RFC5246) support... yes

fallback from TLS 1.6 to... TLS1.2

for RFC7507 inappropriate fallback... yes

for HTTPS server name... Local

for certificate chain order... sorted

for safe renegotiation (RFC5746) support... yes

for Safe renegotiation support (SCSV)... no

for encrypt-then-MAC (RFC7366) support... no

for ext master secret (RFC7627) support... no

for heartbeat (RFC6520) support... no

for version rollback bug in RSA PMS... dunno

for version rollback bug in Client Hello... no

whether the server ignores the RSA PMS version... yes

whether small records (512 bytes) are tolerated on handshake... yes

whether cipher suites not in SSL 3.0 spec are accepted... yes

whether a bogus TLS record version in the client hello is accepted... yes

whether the server understands TLS closure alerts... partially

whether the server supports session resumption... yes

for anonymous authentication support... no

for ephemeral Diffie-Hellman support... no

for ephemeral EC Diffie-Hellman support... yes

ephemeral EC Diffie-Hellman group info... SECP256R1

for AES-128-GCM cipher (RFC5288) support... yes

for AES-128-CCM cipher (RFC6655) support... no

for AES-128-CCM-8 cipher (RFC6655) support... no

for AES-128-CBC cipher (RFC3268) support... yes

for CAMELLIA-128-GCM cipher (RFC6367) support... no

for CAMELLIA-128-CBC cipher (RFC5932) support... no

for 3DES-CBC cipher (RFC2246) support... yes

for ARCFOUR 128 cipher (RFC2246) support... yes

for MD5 MAC support... yes

for SHA1 MAC support... yes

for SHA256 MAC support... yes

for ZLIB compression support... no

for max record size (RFC6066) support... no

for OCSP status response (RFC6066) support... no

for OpenPGP authentication (RFC6091) support... no

You could also use the client to debug services with starttls capability.

$ gnutls-cli-debug --starttls-proto smtp --port 25 localhost

EXIT STATUS

One of the following exit values will be returned:

0 (EXIT_SUCCESS)

Successful program execution.

1 (EXIT_FAILURE)

The operation failed or the command syntax was not valid.

70 (EX_SOFTWARE)

libopts had an internal operational error. Please report it to autogen-users@lists.sourceforge.net. Thank you.

SEE ALSO

gnutls-cli(1), gnutls-serv(1)

AUTHORS

Nikos Mavrogiannopoulos, Simon Josefsson and others; see /usr/share/doc/gnutls/AUTHORS for a complete list.

COPYRIGHT

Copyright (C) 2000-2017 Free Software Foundation, and others all rights reserved. This program is released under the terms of the GNU General Public License, version 3 or later.

BUGS

Please send bug reports to: bugs@gnutls.org

NOTES

This manual page was AutoGen-erated from the gnutls-cli-debug option definitions.

3.5.8 2017-09-02 gnutls-cli-debug(1)