gnutls-cli — GnuTLS client
gnutls-cli
[ −flag
[value
] ...] [ −−opt−name
[[=|]value
] ...] [hostname
]
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.
−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.
−−tofu, −−no−tofu
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.
−−ocsp, −−no−ocsp
Enable OCSP certificate verification. The no−ocsp
form will
disable the option.
This option will enable verification of the peer's certificate using ocsp
−r,
−−resume
Establish a session and resume.
Connect, establish a session, reconnect and resume.
−e,
−−rehandshake
Establish a session and rehandshake.
Connect, establish a session and rehandshake immediately.
−−noticket
Don't accept session tickets.
−s,
−−starttls
Connect, establish a plain session and start TLS..
The TLS session will be initiated when EOF or a SIGALRM is received.
−u,
−−udp
Use DTLS (datagram TLS) over UDP.
−−mtu=number
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
−−crlf
Send CR LF instead of LF.
−−x509fmtder
Use DER format for certificates to read from.
−f,
−−fingerprint
Send the openpgp fingerprint, instead of the key.
−−disable−extensions
Disable all the TLS extensions.
−−print−cert
Print peer's certificate in PEM format.
−−recordsize=number
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
−−dh−bits=number
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.
−−priority=string
Priorities string.
TLS algorithms and protocols to enable. You can use predefined sets of ciphersuites such as PERFORMANCE, NORMAL, SECURE128, SECURE256. Check the GnuTLS manual on section “Priority strings” for more information on allowed keywords
−−x509cafile=string
Certificate file or PKCS #11 URL to use.
−−x509crlfile=file
CRL file to use.
−−pgpkeyfile=file
PGP Key file to use.
−−pgpkeyring=file
PGP Key ring file to use.
−−pgpcertfile=file
PGP Public Key (certificate) file to use.
−−x509keyfile=string
X.509 key file or PKCS #11 URL to use.
−−x509certfile=string
X.509 Certificate file or PKCS #11 URL to use.
−−pgpsubkey=string
PGP subkey to use (hex or auto).
−−srpusername=string
SRP username to use.
−−srppasswd=string
SRP password to use.
−−pskusername=string
PSK username to use.
−−pskkey=string
PSK key (in hex) to use.
−p
string
,
−−port=string
The port or service to connect to.
−−insecure
Don't abort program if server certificate can't be validated.
−−benchmark−ciphers
Benchmark individual ciphers.
−−benchmark−soft−ciphers
Benchmark individual software ciphers (no hw acceleration).
−−benchmark−tls−kx
Benchmark TLS key exchange methods.
−−benchmark−tls−ciphers
Benchmark TLS ciphers.
−l,
−−list
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.
−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.
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
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.