path: root/doc/cha-programs.texi

@node Included programs
@chapter Included programs

Included with @acronym{GnuTLS} are also a few command line tools that
let you use the library for common tasks without writing an
application.  The applications are discussed in this chapter.

@menu
* Invoking certtool::
* Invoking gnutls-cli::
* Invoking gnutls-cli-debug::
* Invoking gnutls-serv::
* Invoking psktool::
* Invoking srptool::
* Invoking p11tool::
@end menu

@node Invoking certtool
@section Invoking certtool
@cindex certtool

This is a program to generate @acronym{X.509} certificates, certificate
requests, CRLs and private keys.

@example
Certtool help
Usage: certtool [options]
     -s, --generate-self-signed 
                              Generate a self-signed certificate.
     -c, --generate-certificate 
                              Generate a signed certificate.
     --generate-proxy         Generate a proxy certificate.
     --generate-crl           Generate a CRL.
     -u, --update-certificate 
                              Update a signed certificate.
     -p, --generate-privkey   Generate a private key.
     -q, --generate-request   Generate a PKCS #10 certificate 
                              request.
     -e, --verify-chain       Verify a PEM encoded certificate chain. 
                              The last certificate in the chain must 
                              be a self signed one.
     --verify                 Verify a PEM encoded certificate chain. 
                              CA certificates must be loaded with 
                              --load-ca-certificate.
     --verify-crl             Verify a CRL.
     --generate-dh-params     Generate PKCS #3 encoded Diffie-Hellman 
                              parameters.
     --get-dh-params          Get the included PKCS #3 encoded 
                              Diffie-Hellman parameters.
     --load-privkey FILE      Private key file to use.
     --load-pubkey FILE       Public key file to use.
     --load-request FILE      Certificate request file to use.
     --load-certificate FILE  
                              Certificate file to use.
     --load-ca-privkey FILE   Certificate authority's private key 
                              file to use.
     --load-ca-certificate FILE  
                              Certificate authority's certificate 
                              file to use.
     --password PASSWORD      Password to use.
     -i, --certificate-info   Print information on a certificate.
     --certificate-pubkey     Print certificate public key.
     --pgp-certificate-info   Print information on a OpenPGP 
                              certificate.
     --pgp-ring-info          Print information on a keyring 
                              structure.
     -l, --crl-info           Print information on a CRL.
     --crq-info               Print information on a Certificate 
                              Request.
     --no-crq-extensions      Do not use extensions in certificate 
                              requests.
     --p12-info               Print information on a PKCS #12 
                              structure.
     --p7-info                Print information on a PKCS #7 
                              structure.
     --smime-to-p7            Convert S/MIME to PKCS #7 structure.
     -k, --key-info           Print information on a private key.
     --pgp-key-info           Print information on a OpenPGP private 
                              key.
     --pubkey-info            Print information on a public key.
     --fix-key                Regenerate the parameters in a private 
                              key.
     --v1                     Generate an X.509 version 1 certificate 
                              (no extensions).
     --to-p12                 Generate a PKCS #12 structure.
     --to-p8                  Generate a PKCS #8 key structure.
     -8, --pkcs8              Use PKCS #8 format for private keys.
     --dsa                    Use DSA keys.
     --ecc                    Use ECC (ECDSA) keys.
     --hash STR               Hash algorithm to use for signing 
                              (MD5,SHA1,RMD160,SHA256,SHA384,SHA512).
     --export-ciphers         Use weak encryption algorithms.
     --inder                  Use DER format for input certificates 
                              and private keys.
     --inraw                  Use RAW/DER format for input 
                              certificates and private keys.
     --outder                 Use DER format for output certificates 
                              and private keys.
     --outraw                 Use RAW/DER format for output 
                              certificates and private keys.
     --bits BITS              specify the number of bits for key 
                              generation.
     --sec-param PARAM        specify the security level 
                              [low|normal|high|ultra].
     --disable-quick-random   Use /dev/random for key generationg, 
                              thus increasing the quality of 
                              randomness used.
     --outfile FILE           Output file.
     --infile FILE            Input file.
     --template FILE          Template file to use for non 
                              interactive operation.
     --pkcs-cipher CIPHER     Cipher to use for pkcs operations 
                              (3des,3des-pkcs12,aes-128,aes-192,aes-25
                              6,rc2-40,arcfour).
     -d, --debug LEVEL        specify the debug level. Default is 1.
     -h, --help               shows this help text
     -v, --version            shows the program's version
@end example

The program can be used interactively or non interactively by
specifying the @code{--template} command line option. See below for an
example of a template file.

@subsection Diffie-Hellman parameter generation
To generate parameters for Diffie-Hellman key exchange, use the command:
@smallexample
$ certtool --generate-dh-params --outfile dh.pem
@end smallexample

@subsection Self-signed certificate generation

To create a self signed certificate, use the command:
@smallexample
$ certtool --generate-privkey --outfile ca-key.pem
$ certtool --generate-self-signed --load-privkey ca-key.pem \
   --outfile ca-cert.pem
@end smallexample

Note that a self-signed certificate usually belongs to a certificate
authority, that signs other certificates.

@subsection Private key generation
To create a private key (RSA by default), run:

@smallexample
$ certtool --generate-privkey --outfile key.pem
@end smallexample

To create a DSA or elliptic curves (ECDSA) private key use the
above command combined with @code{--dsa} or @code{--ecc} options.

@subsection Certificate generation
To generate a certificate using the private key, use the command:

@smallexample
$ certtool --generate-certificate --load-privkey key.pem \
   --outfile cert.pem --load-ca-certificate ca-cert.pem \
   --load-ca-privkey ca-key.pem
@end smallexample

Alternatively you may create a certificate request, which is needed
when the certificate will be signed by a third party authority.

@smallexample
$ certtool --generate-request --load-privkey key.pem \
  --outfile request.pem
@end smallexample

If the private key is stored in a smart card you can generate
a request by specifying the private key object URL (see @ref{Invoking p11tool}
on how to obtain the URL).

@smallexample
$ certtool --generate-request --load-privkey pkcs11:(PRIVKEY URL) \
  --load-pubkey pkcs11:(PUBKEY URL) --outfile request.pem
@end smallexample

To generate a certificate using the previous request, use the command:

@smallexample
$ certtool --generate-certificate --load-request request.pem \
   --outfile cert.pem \
   --load-ca-certificate ca-cert.pem --load-ca-privkey ca-key.pem
@end smallexample

@subsection Certificate information
To view the certificate information, use:

@smallexample
$ certtool --certificate-info --infile cert.pem
@end smallexample

@subsection @acronym{PKCS} #12 structure generation
To generate a @acronym{PKCS} #12 structure using the previous key and
certificate, use the command:

@smallexample
$ certtool --load-certificate cert.pem --load-privkey key.pem \
  --to-p12 --outder --outfile key.p12
@end smallexample

Some tools (reportedly web browsers) have problems with that file
because it does not contain the CA certificate for the certificate.
To work around that problem in the tool, you can use the
--load-ca-certificate parameter as follows:

@smallexample
$ certtool --load-ca-certificate ca.pem \
  --load-certificate cert.pem --load-privkey key.pem \
  --to-p12 --outder --outfile key.p12
@end smallexample

@subsection Proxy certificate generation
Proxy certificate can be used to delegate your credential to a
temporary, typically short-lived, certificate.  To create one from the
previously created certificate, first create a temporary key and then
generate a proxy certificate for it, using the commands:

@smallexample
$ certtool --generate-privkey > proxy-key.pem
$ certtool --generate-proxy --load-ca-privkey key.pem \
  --load-privkey proxy-key.pem --load-certificate cert.pem \
  --outfile proxy-cert.pem
@end smallexample

@subsection Certificate revocation list generation
To create an empty Certificate Revocation List (CRL) do:

@smallexample
$ certtool --generate-crl --load-ca-privkey x509-ca-key.pem \
           --load-ca-certificate x509-ca.pem
@end smallexample

To create a CRL that contains some revoked certificates, place the
certificates in a file and use @code{--load-certificate} as follows:

@smallexample
$ certtool --generate-crl --load-ca-privkey x509-ca-key.pem \
  --load-ca-certificate x509-ca.pem --load-certificate revoked-certs.pem
@end smallexample

To verify a Certificate Revocation List (CRL) do:

@smallexample
$ certtool --verify-crl --load-ca-certificate x509-ca.pem < crl.pem
@end smallexample



@subsection Certtool's template file format:
A template file can be used to avoid the interactive questions of
certtool. Initially create a file named 'cert.cfg' that contains the information
about the certificate. The template can be used as below:

@smallexample
$ certtool --generate-certificate cert.pem --load-privkey key.pem  \
   --template cert.cfg \
   --load-ca-certificate ca-cert.pem --load-ca-privkey ca-key.pem
@end smallexample

An example certtool template file:

@example
# X.509 Certificate options
#
# DN options

# The organization of the subject.
organization = "Koko inc."

# The organizational unit of the subject.
unit = "sleeping dept."

# The locality of the subject.
# locality =

# The state of the certificate owner.
state = "Attiki"

# The country of the subject. Two letter code.
country = GR

# The common name of the certificate owner.
cn = "Cindy Lauper"

# A user id of the certificate owner.
#uid = "clauper"

# If the supported DN OIDs are not adequate you can set
# any OID here.
# For example set the X.520 Title and the X.520 Pseudonym
# by using OID and string pairs.
#dn_oid = "2.5.4.12" "Dr." "2.5.4.65" "jackal"

# This is deprecated and should not be used in new
# certificates.
# pkcs9_email = "none@@none.org"

# The serial number of the certificate
serial = 007

# In how many days, counting from today, this certificate will expire.
expiration_days = 700

# X.509 v3 extensions

# A dnsname in case of a WWW server.
#dns_name = "www.none.org"
#dns_name = "www.morethanone.org"

# An IP address in case of a server.
#ip_address = "192.168.1.1"

# An email in case of a person
email = "none@@none.org"

# An URL that has CRLs (certificate revocation lists)
# available. Needed in CA certificates.
#crl_dist_points = "http://www.getcrl.crl/getcrl/"

# Whether this is a CA certificate or not
#ca

# Whether this certificate will be used for a TLS client
#tls_www_client

# Whether this certificate will be used for a TLS server
#tls_www_server

# Whether this certificate will be used to sign data (needed
# in TLS DHE ciphersuites).
signing_key

# Whether this certificate will be used to encrypt data (needed
# in TLS RSA ciphersuites). Note that it is preferred to use different
# keys for encryption and signing.
#encryption_key

# Whether this key will be used to sign other certificates.
#cert_signing_key

# Whether this key will be used to sign CRLs.
#crl_signing_key

# Whether this key will be used to sign code.
#code_signing_key

# Whether this key will be used to sign OCSP data.
#ocsp_signing_key

# Whether this key will be used for time stamping.
#time_stamping_key

# Whether this key will be used for IPsec IKE operations.
#ipsec_ike_key
@end example

@node Invoking gnutls-cli
@section Invoking gnutls-cli
@cindex gnutls-cli

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.

@example
GnuTLS test client
Usage:  gnutls-cli [options] hostname

     -d, --debug integer      Enable debugging
     -r, --resume             Connect, establish a session. Connect
                              again and resume this session.
     -s, --starttls           Connect, establish a plain session and
                              start TLS when EOF or a SIGALRM is
                              received.
     --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 the certificate in PEM format.
     --recordsize integer     The maximum record size to advertize.
     -V, --verbose            More verbose output.
     --ciphers cipher1 cipher2...
                              Ciphers to enable.
     --protocols protocol1 protocol2...
                              Protocols to enable.
     --comp comp1 comp2...    Compression methods to enable.
     --macs mac1 mac2...      MACs to enable.
     --kx kx1 kx2...          Key exchange methods to enable.
     --ctypes certType1 certType2...
                              Certificate types to enable.
     --priority PRIORITY STRING
                              Priorities string.
     --x509cafile FILE        Certificate file 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.
     --pgpsubkey HEX|auto     PGP subkey to use.
     --x509keyfile FILE       X.509 key file to use.
     --x509certfile FILE      X.509 Certificate file to use.
     --srpusername NAME       SRP username to use.
     --srppasswd PASSWD       SRP password to use.
     --pskusername NAME       PSK username to use.
     --pskkey KEY             PSK key (in hex) to use.
     --opaque-prf-input DATA
                              Use Opaque PRF Input DATA.
     -p, --port PORT          The port to connect to.
     --insecure               Don't abort program if server
                              certificate can't be validated.
     -l, --list               Print a list of the supported
                              algorithms and modes.
     -h, --help               prints this help
     -v, --version            prints the program's version number
@end example

@menu
* Example client PSK connection::
@end menu

@node Example client PSK connection
@subsection Example client PSK connection
@cindex PSK client

To connect to a server using PSK authentication, you may use something
like:

@smallexample
$ gnutls-cli -p 5556 test.gnutls.org --pskusername jas \
  --pskkey 9e32cf7786321a828ef7668f09fb35db \
  --priority NORMAL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK
@end smallexample

If your server only supports the PSK ciphersuite, connecting to it
should be as simple as connecting to the server:

@smallexample
$ ./gnutls-cli -p 5556 localhost
Resolving 'localhost'...
Connecting to '127.0.0.1:5556'...
- PSK client callback.
Enter PSK identity: psk_identity
Enter password: 
- PSK authentication.
- Version: TLS1.1
- Key Exchange: PSK
- Cipher: AES-128-CBC
- MAC: SHA1
- Compression: NULL
- Handshake was completed

- Simple Client Mode:
@end smallexample

If the server supports several cipher suites, you may need to force it
to chose PSK by using a cipher priority parameter such as in the
example below:

@smallexample
$ ./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:
@end smallexample

By keeping the @code{--pskusername} parameter and removing the
@code{--pskkey} parameter, it will query only for the password during
the handshake.

@node Invoking gnutls-cli-debug
@section Invoking gnutls-cli-debug
@cindex gnutls-cli-debug

This program was created to assist in debugging @acronym{GnuTLS}, but
it might be useful to extract a @acronym{TLS} server's capabilities.
It's purpose is to connect onto a @acronym{TLS} server, perform some
tests and print the server's capabilities. If called with the `-v'
parameter more checks will be performed. An example output is:

@example
crystal:/cvs/gnutls/src$ ./gnutls-cli-debug localhost -p 5556
Resolving 'localhost'...
Connecting to '127.0.0.1:5556'...
Checking for TLS 1.1 support... yes
Checking fallback from TLS 1.1 to... N/A
Checking for TLS 1.0 support... yes
Checking for SSL 3.0 support... yes
Checking for version rollback bug in RSA PMS... no
Checking for version rollback bug in Client Hello... no
Checking whether we need to disable TLS 1.0... N/A
Checking whether the server ignores the RSA PMS version... no
Checking whether the server can accept Hello Extensions... yes
Checking whether the server can accept cipher suites not in SSL 3.0 spec... yes
Checking for certificate information... N/A
Checking for trusted CAs... N/A
Checking whether the server understands TLS closure alerts... yes
Checking whether the server supports session resumption... yes
Checking for export-grade ciphersuite support... no
Checking RSA-export ciphersuite info... N/A
Checking for anonymous authentication support... no
Checking anonymous Diffie-Hellman group info... N/A
Checking for ephemeral Diffie-Hellman support... no
Checking ephemeral Diffie-Hellman group info... N/A
Checking for AES cipher support (TLS extension)... yes
Checking for 3DES cipher support... yes
Checking for ARCFOUR 128 cipher support... yes
Checking for ARCFOUR 40 cipher support... no
Checking for MD5 MAC support... yes
Checking for SHA1 MAC support... yes
Checking for ZLIB compression support (TLS extension)... yes
Checking for max record size (TLS extension)... yes
Checking for SRP authentication support (TLS extension)... yes
Checking for OpenPGP authentication support (TLS extension)... no
@end example

@node Invoking gnutls-serv
@section Invoking gnutls-serv
@cindex gnutls-serv

Simple server program that listens to incoming TLS connections.

@example
GnuTLS test server
Usage: gnutls-serv [options]

     -d, --debug integer      Enable debugging
     -g, --generate           Generate Diffie-Hellman Parameters.
     -p, --port integer       The port to connect to.
     -q, --quiet              Suppress some messages.
     --nodb                   Does not use the resume database.
     --http                   Act as an HTTP Server.
     --echo                   Act as an Echo Server.
     --dhparams FILE          DH params file to use.
     --x509fmtder             Use DER format for certificates
     --x509cafile FILE        Certificate file to use.
     --x509crlfile FILE       CRL file to use.
     --pgpkeyring FILE        PGP Key ring file to use.
     --pgpkeyfile FILE        PGP Key file to use.
     --pgpcertfile FILE       PGP Public Key (certificate) file to
                              use.
     --pgpsubkey HEX|auto     PGP subkey to use.
     --x509keyfile FILE       X.509 key file to use.
     --x509certfile FILE      X.509 Certificate file to use.
     --x509dsakeyfile FILE    Alternative X.509 key file to use.
     --x509dsacertfile FILE   Alternative X.509 certificate file to
                              use.
     -r, --require-cert       Require a valid certificate.
     -a, --disable-client-cert
                              Disable request for a client
                              certificate.
     --pskpasswd FILE         PSK password file to use.
     --pskhint HINT           PSK identity hint to use.
     --srppasswd FILE         SRP password file to use.
     --srppasswdconf FILE     SRP password conf file to use.
     --opaque-prf-input DATA
                              Use Opaque PRF Input DATA.
     --ciphers cipher1 cipher2...
                              Ciphers to enable.
     --protocols protocol1 protocol2...
                              Protocols to enable.
     --comp comp1 comp2...    Compression methods to enable.
     --macs mac1 mac2...      MACs to enable.
     --kx kx1 kx2...          Key exchange methods to enable.
     --ctypes certType1 certType2...
                              Certificate types to enable.
     --priority PRIORITY STRING
                              Priorities string.
     -l, --list               Print a list of the supported
                              algorithms  and modes.
     -h, --help               prints this help
     -v, --version            prints the program's version number
@end example

@subsection Setting up a test HTTPS server
@cindex HTTPS server
@cindex debug server

Running your own TLS server based on GnuTLS can be useful when
debugging clients and/or GnuTLS itself.  This section describes how to
use @code{gnutls-serv} as a simple HTTPS server.

The most basic server can be started as:

@smallexample
gnutls-serv --http
@end smallexample

It will only support anonymous ciphersuites, which many TLS clients
refuse to use.

The next step is to add support for X.509.  First we generate a CA:

@smallexample
$ certtool --generate-privkey > x509-ca-key.pem
$ echo 'cn = GnuTLS test CA' > ca.tmpl
$ echo 'ca' >> ca.tmpl
$ echo 'cert_signing_key' >> ca.tmpl
$ certtool --generate-self-signed --load-privkey x509-ca-key.pem \
  --template ca.tmpl --outfile x509-ca.pem
...
@end smallexample

Then generate a server certificate.  Remember to change the dns_name
value to the name of your server host, or skip that command to avoid
the field.

@example
$ certtool --generate-privkey > x509-server-key.pem
$ echo 'organization = GnuTLS test server' > server.tmpl
$ echo 'cn = test.gnutls.org' >> server.tmpl
$ echo 'tls_www_server' >> server.tmpl
$ echo 'encryption_key' >> server.tmpl
$ echo 'signing_key' >> server.tmpl
$ echo 'dns_name = test.gnutls.org' >> server.tmpl
$ certtool --generate-certificate --load-privkey x509-server-key.pem \
  --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem \
  --template server.tmpl --outfile x509-server.pem
...
@end example

For use in the client, you may want to generate a client certificate
as well.

@example
$ certtool --generate-privkey > x509-client-key.pem
$ echo 'cn = GnuTLS test client' > client.tmpl
$ echo 'tls_www_client' >> client.tmpl
$ echo 'encryption_key' >> client.tmpl
$ echo 'signing_key' >> client.tmpl
$ certtool --generate-certificate --load-privkey x509-client-key.pem \
  --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem \
  --template client.tmpl --outfile x509-client.pem
...
@end example

To be able to import the client key/certificate into some
applications, you will need to convert them into a PKCS#12 structure.
This also encrypts the security sensitive key with a password.

@smallexample
$ certtool --to-p12 --load-ca-certificate x509-ca.pem \
  --load-privkey x509-client-key.pem --load-certificate x509-client.pem \
  --outder --outfile x509-client.p12
@end smallexample

For icing, we'll create a proxy certificate for the client too.

@smallexample
$ certtool --generate-privkey > x509-proxy-key.pem
$ echo 'cn = GnuTLS test client proxy' > proxy.tmpl
$ certtool --generate-proxy --load-privkey x509-proxy-key.pem \
  --load-ca-certificate x509-client.pem --load-ca-privkey x509-client-key.pem \
  --load-certificate x509-client.pem --template proxy.tmpl \
  --outfile x509-proxy.pem
...
@end smallexample

Then start the server again:

@smallexample
$ gnutls-serv --http \
            --x509cafile x509-ca.pem \
            --x509keyfile x509-server-key.pem \
            --x509certfile x509-server.pem
@end smallexample

Try connecting to the server using your web browser.  Note that the
server listens to port 5556 by default.

While you are at it, to allow connections using DSA, you can also
create a DSA key and certificate for the server.  These credentials
will be used in the final example below.

@smallexample
$ certtool --generate-privkey --dsa > x509-server-key-dsa.pem
$ certtool --generate-certificate --load-privkey x509-server-key-dsa.pem \
  --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem \
  --template server.tmpl --outfile x509-server-dsa.pem
...
@end smallexample

The next step is to create OpenPGP credentials for the server.

@smallexample
gpg --gen-key
...enter whatever details you want, use 'test.gnutls.org' as name...
@end smallexample

Make a note of the OpenPGP key identifier of the newly generated key,
here it was @code{5D1D14D8}.  You will need to export the key for
GnuTLS to be able to use it.

@smallexample
gpg -a --export 5D1D14D8 > openpgp-server.txt
gpg --export 5D1D14D8 > openpgp-server.bin
gpg --export-secret-keys 5D1D14D8 > openpgp-server-key.bin
gpg -a --export-secret-keys 5D1D14D8 > openpgp-server-key.txt
@end smallexample

Let's start the server with support for OpenPGP credentials:

@smallexample
gnutls-serv --http \
            --pgpkeyfile openpgp-server-key.txt \
            --pgpcertfile openpgp-server.txt
@end smallexample

The next step is to add support for SRP authentication.

@smallexample
srptool --create-conf srp-tpasswd.conf
srptool --passwd-conf srp-tpasswd.conf --username jas --passwd srp-passwd.txt
Enter password: [TYPE "foo"]
@end smallexample

Start the server with SRP support:

@smallexample
gnutls-serv --http \
            --srppasswdconf srp-tpasswd.conf \
            --srppasswd srp-passwd.txt
@end smallexample

Let's also add support for PSK.

@smallexample
$ psktool --passwd psk-passwd.txt
@end smallexample

Start the server with PSK support:

@smallexample
gnutls-serv --http \
            --pskpasswd psk-passwd.txt
@end smallexample

Finally, we start the server with all the earlier parameters and you
get this command:

@smallexample
gnutls-serv --http \
            --x509cafile x509-ca.pem \
            --x509keyfile x509-server-key.pem \
            --x509certfile x509-server.pem \
            --x509dsakeyfile x509-server-key-dsa.pem \
            --x509dsacertfile x509-server-dsa.pem \
            --pgpkeyfile openpgp-server-key.txt \
            --pgpcertfile openpgp-server.txt \
            --srppasswdconf srp-tpasswd.conf \
            --srppasswd srp-passwd.txt \
            --pskpasswd psk-passwd.txt
@end smallexample

@menu
* Example server PSK connection::
@end menu

@node Example server PSK connection
@subsection Example server PSK connection
@cindex PSK server

To set up a PSK server with @code{gnutls-serv} you need to create PSK
password file. This is illustrated in the example below, where a password
is provided at the prompt.

@smallexample
$ ./psktool -u psk_identity -p psks.txt
Enter password:
Key stored to psks.txt
$ cat psks.txt
psk_identity:88f3824b3e5659f52d00e959bacab954b6540344
$
@end smallexample

After this, start the server pointing to the password file.  We
disable DHE-PSK.

@smallexample
$ ./gnutls-serv --pskpasswd psks.txt  --pskhint psk_identity_hint \
  --priority NORMAL:-DHE-PSK
Set static Diffie-Hellman parameters, consider --dhparams.
Echo Server ready. Listening to port '5556'.
@end smallexample

You can now connect to the server using a PSK client as in @ref{Example
client PSK connection}.

@node Invoking psktool
@section Invoking psktool
@cindex psktool

This is a program to manage @acronym{PSK} username and keys.

@smallexample
PSKtool help
Usage : psktool [options]
     -u, --username username
                              specify username.
     -p, --passwd FILE        specify a password file.
     -s, --keysize SIZE       specify the key size in bytes.
     -v, --version            prints the program's version number
     -h, --help               shows this help text
@end smallexample

Normally the file will generate random keys for the indicated username.

@node Invoking srptool
@section Invoking srptool
@anchor{srptool}
@cindex srptool

The @file{srptool} is a very simple program that emulates the programs
in the @emph{Stanford SRP libraries}@footnote{See
@url{http://srp.stanford.edu/}.}.  It is intended for use in places
where you don't expect @acronym{SRP} authentication to be the used for
system users.

Traditionally @emph{libsrp} used two files. One called @code{tpasswd}
which holds usernames and verifiers, and @code{tpasswd.conf} which
holds generators and primes.

@subsection How to use srptool

To create tpasswd.conf which holds the g and n values for
@acronym{SRP} protocol (generator and a large prime), run:

@smallexample
$ srptool --create-conf /etc/tpasswd.conf
@end smallexample

This command will create /etc/tpasswd and will add user 'test' (you
will also be prompted for a password).  Verifiers are stored by
default in the way libsrp expects.

@smallexample
$ srptool --passwd /etc/tpasswd \
    --passwd-conf /etc/tpasswd.conf -u test
@end smallexample

This command will check against a password.  If the password matches
the one in /etc/tpasswd you will get an ok.

@smallexample
$ srptool --passwd /etc/tpasswd \
    --passwd-conf /etc/tpasswd.conf --verify -u test
@end smallexample

@node Invoking p11tool
@section Invoking p11tool
@anchor{p11tool}
@cindex p11tool

The @file{p11tool} is a program that helps with accessing tokens
and security modules that support the PKCS #11 API. It requires
the individual PKCS #11 modules to be loaded either with the
@code{--provider} option, or by setting up the GnuTLS configuration
file for PKCS #11 as in @ref{Hardware tokens}.

@example
p11tool help
Usage: p11tool [options]
Usage: p11tool --list-tokens
Usage: p11tool --list-all
Usage: p11tool --export 'pkcs11:...'

     --export URL             Export an object specified by a pkcs11 
                              URL
     --list-tokens            List all available tokens
     --list-mechanisms URL    List all available mechanisms in token.
     --list-all               List all objects specified by a PKCS#11 
                              URL
     --list-all-certs         List all certificates specified by a 
                              PKCS#11 URL
     --list-certs             List certificates that have a private 
                              key specified by a PKCS#11 URL
     --list-privkeys          List private keys specified by a 
                              PKCS#11 URL
     --list-trusted           List certificates marked as trusted, 
                              specified by a PKCS#11 URL
     --initialize URL         Initializes a PKCS11 token.
     --write URL              Writes loaded certificates, private or 
                              secret keys to a PKCS11 token.
     --delete URL             Deletes objects matching the URL.
     --label label            Sets a label for the write operation.
     --trusted                Marks the certificate to be written as 
                              trusted.
     --private                Marks the object to be written as 
                              private (requires PIN).
     --no-private             Marks the object to be written as not 
                              private.
     --login                  Force login to token
     --detailed-url           Export detailed URLs.
     --no-detailed-url        Export less detailed URLs.
     --secret-key HEX_KEY     Provide a hex encoded secret key.
     --load-privkey FILE      Private key file to use.
     --load-pubkey FILE       Private key file to use.
     --load-certificate FILE  
                              Certificate file to use.
     -8, --pkcs8              Use PKCS #8 format for private keys.
     --inder                  Use DER format for input certificates 
                              and private keys.
     --inraw                  Use RAW/DER format for input 
                              certificates and private keys.
     --provider Library       Specify the pkcs11 provider library
     --outfile FILE           Output file.
     -d, --debug LEVEL        specify the debug level. Default is 1.
     -h, --help               shows this help text
@end example

After being provided the available PKCS #11 modules, it can list all tokens 
available in your system, the objects on the tokens, and perform operations
on them.

Some examples on how to use p11tool are illustrated in the following  paragraphs.

@subsection List all tokens
@smallexample
$ p11tool --list-tokens
@end smallexample

@subsection List all objects
The following command will list all objects in a token. The @code{--login}
is required to show objects marked as private.
@smallexample
$ p11tool --login --list-all
@end smallexample

@subsection Exporting an object
To retrieve an object stored in the card use the following command.
Note however that objects marked as sensitive (typically PKCS #11 private keys) 
are not allowed to be extracted from the token.
@smallexample 
$ p11tool --login --export pkcs11:(OBJECT URL)
@end smallexample

@subsection Copy an object to a token
To copy an object, such as a certificate or private key to a token
use the following command.
@smallexample 
$ p11tool --login --write pkcs11:(TOKEN URL) \
  --load-certificate cert.pem --label "my_cert"
@end smallexample