Gnutls client
gnutls-cli [-flags] [-flag [value]] [--option-name[[=| ]value]] [hostname]
Operands and options may be intermixed. They will be reordered.
Simple client program to set up a TLS connection to some other computer. It sets up a TLS connection and forwards data from the standard input to the secured socket and vice versa.
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.
More verbose output.
This option may appear an unlimited number of times.
Enable trust on first use authentication.
The no-tofu form will disable the option.
This option will, in addition to certificate authentication, perform authentication based on previously seen public keys, a model similar to SSH authentication. Note that when tofu is specified (PKI) and DANE authentication will become advisory to assist the public key acceptance process.
Fail to connect if a known certificate has changed.
The no-strict-tofu form will disable the option.
This option will perform authentication as with option --tofu; however, while --tofu asks whether to trust a changed public key, this option will fail in case of public key changes.
Enable DANE certificate verification (DNSSEC).
The no-dane form will disable the option.
This option will, in addition to certificate authentication using the trusted CAs, verify the server certificates using on the DANE information available via DNSSEC.
Use the local DNS server for DNSSEC resolving.
The no-local-dns form will disable the option.
This option will use the local DNS server for DNSSEC. This is disabled by default due to many servers not allowing DNSSEC.
Disable CA certificate verification.
The no-ca-verification form will disable the option. This option is enabled by default.
This option will disable CA certificate verification. It is to be used with the --dane or --tofu options.
Enable OCSP certificate verification.
The no-ocsp form will disable the option.
This option will enable verification of the peer's certificate using ocsp
Establish a session and resume.
Connect, establish a session, reconnect and resume.
Establish a session and rehandshake.
Connect, establish a session and rehandshake immediately.
Connect, establish a plain session and start TLS.
The TLS session will be initiated when EOF or a SIGALRM is received.
Use DTLS (datagram TLS) over UDP.
Set MTU for datagram TLS.
This option takes an integer number as its argument. The value of number is constrained to being:
in the range 0 through 17000
Send CR LF instead of LF.
Use DER format for certificates to read from.
Send the openpgp fingerprint, instead of the key.
Print peer's certificate in PEM format.
The minimum number of bits allowed for DH.
This option takes an integer number as its argument.
This option sets the minimum number of bits allowed for a Diffie-Hellman key exchange. You may want to lower the default value if the peer sends a weak prime and you get an connection error with unacceptable prime.
Priorities string.
TLS algorithms and protocols to enable. You can use predefined sets of ciphersuites such as PERFORMANCE, NORMAL, PFS, SECURE128, SECURE256. The default is NORMAL.
Check the GnuTLS manual on section “Priority strings” for more information on the allowed keywords
Certificate file or PKCS #11 URL to use.
CRL file to use.
PGP Key file to use.
PGP Key ring file to use.
PGP Public Key (certificate) file to use.
X.509 key file or PKCS #11 URL to use.
X.509 Certificate file or PKCS #11 URL to use.
PGP subkey to use (hex or auto).
SRP username to use.
SRP password to use.
PSK username to use.
PSK key (in hex) to use.
The port or service to connect to.
Don't abort program if server certificate can't be validated.
Use length-hiding padding to prevent traffic analysis.
When possible (e.g., when using CBC ciphersuites), use length-hiding padding to prevent traffic analysis.
Benchmark individual ciphers.
Benchmark TLS key exchange methods.
Benchmark TLS ciphers.
Print a list of the supported algorithms and modes.
Print a list of the supported algorithms and modes. If a priority string is given then only the enabled ciphersuites are shown.
Don't allow session tickets.
Offer SRTP profiles.
Application layer protocol.
This option may appear an unlimited number of times.
This option will set and enable the Application Layer Protocol Negotiation (ALPN) in the TLS protocol.
Activate heartbeat support.
The maximum record size to advertize.
This option takes an integer number as its argument. The value of number is constrained to being:
in the range 0 through 4096
Do not send a Server Name Indication (SNI).
Disable all the TLS extensions.
This option disables all TLS extensions. Deprecated option. Use the priority string.
Inline commands of the form ^<cmd>^.
Enable inline commands of the form ^<cmd>^. The inline commands are expected to be in a line by themselves. The available commands are: resume and renegotiate.
Change the default (^) used as a delimiter for inline commands.
The value is a single US-ASCII character (octets 0 - 127)..
Change the default (^) delimiter used for inline commands. The delimiter is expected to be a single US-ASCII character (octets 0 - 127). This option is only relevant if inline commands are enabled via the inline-commands option
Specify the PKCS #11 provider library.
This will override the default options in /etc/gnutls/pkcs11.conf
Reports the status of the FIPS140-2 mode in gnutls library.
Display usage information and exit.
Pass the extended usage information through a pager.
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.
Connecting using PSK authentication
To connect to a server using PSK authentication, you need to enable the choice of PSK by using a cipher priority parameter such as in the example below.
$ ./gnutls-cli -p 5556 localhost --pskusername psk_identity --pskkey 88f3824b3e5659f52d00e959bacab954b6540344 --priority NORMAL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK Resolving 'localhost'... Connecting to '127.0.0.1:5556'... - PSK authentication. - Version: TLS1.1 - Key Exchange: PSK - Cipher: AES-128-CBC - MAC: SHA1 - Compression: NULL - Handshake was completed - Simple Client Mode:
By keeping the --pskusername parameter and removing the --pskkey parameter, it will query only for the password during the handshake.
Listing ciphersuites in a priority string
To list the ciphersuites in a priority string:
$ ./gnutls-cli --priority SECURE192 -l Cipher suites for SECURE192 TLS_ECDHE_ECDSA_AES_256_CBC_SHA384 0xc0, 0x24 TLS1.2 TLS_ECDHE_ECDSA_AES_256_GCM_SHA384 0xc0, 0x2e TLS1.2 TLS_ECDHE_RSA_AES_256_GCM_SHA384 0xc0, 0x30 TLS1.2 TLS_DHE_RSA_AES_256_CBC_SHA256 0x00, 0x6b TLS1.2 TLS_DHE_DSS_AES_256_CBC_SHA256 0x00, 0x6a TLS1.2 TLS_RSA_AES_256_CBC_SHA256 0x00, 0x3d TLS1.2 Certificate types: CTYPE-X.509 Protocols: VERS-TLS1.2, VERS-TLS1.1, VERS-TLS1.0, VERS-SSL3.0, VERS-DTLS1.0 Compression: COMP-NULL Elliptic curves: CURVE-SECP384R1, CURVE-SECP521R1 PK-signatures: SIGN-RSA-SHA384, SIGN-ECDSA-SHA384, SIGN-RSA-SHA512, SIGN-ECDSA-SHA512
Connecting using a PKCS #11 token
To connect to a server using a certificate and a private key present in a PKCS #11 token you need to substitute the PKCS 11 URLs in the x509certfile and x509keyfile parameters.
Those can be found using "p11tool --list-tokens" and then listing all the objects in the needed token, and using the appropriate.
$ p11tool --list-tokens Token 0: URL: pkcs11:model=PKCS15;manufacturer=MyMan;serial=1234;token=Test Label: Test Manufacturer: EnterSafe Model: PKCS15 Serial: 1234 $ p11tool --login --list-certs "pkcs11:model=PKCS15;manufacturer=MyMan;serial=1234;token=Test" Object 0: URL: pkcs11:model=PKCS15;manufacturer=MyMan;serial=1234;token=Test;object=client;object-type=cert Type: X.509 Certificate Label: client ID: 2a:97:0d:58:d1:51:3c:23:07:ae:4e:0d:72:26:03:7d:99:06:02:6a $ export MYCERT="pkcs11:model=PKCS15;manufacturer=MyMan;serial=1234;token=Test;object=client;object-type=cert" $ export MYKEY="pkcs11:model=PKCS15;manufacturer=MyMan;serial=1234;token=Test;object=client;object-type=private" $ gnutls-cli www.example.com --x509keyfile $MYKEY --x509certfile MYCERT
Notice that the private key only differs from the certificate in the object-type.
One of the following exit values will be returned:
Successful program execution.
The operation failed or the command syntax was not valid.
libopts had an internal operational error. Please report
it to [email protected]. Thank you.
gnutls-cli-debug(1), gnutls-serv(1)
Nikos Mavrogiannopoulos, Simon Josefsson and others; see /usr/share/doc/gnutls/AUTHORS for a complete list.
Copyright (C) 2000-2014 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.
Please send bug reports to: [email protected]
This manual page was AutoGen-erated from the gnutls-cli option definitions.