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       certtool - Manipulate certificates and keys.


       certtool [options]


       Generate X.509 certificates, certificate requests, and private keys.


   Program control options
       -d, --debug LEVEL
              Specify the debug level. Default is 1.

       -h, --help
              Shows this help text

       -v, --version
              Shows the program’s version

   Getting information on X.509 certificates
       -i, --certificate-info
              Print information on a certificate.

       -k, --key-info
              Print information on a private key.

       -l, --crl-info
              Print information on a CRL.

              Print information on a PKCS #12 structure.

   Getting information on Openpgp certificates
              Print information on an OpenPGP certificate.

              Print information on an OpenPGP private key.

              Print information on a keyring.

   Generating/verifying X.509 certificates/keys
       -c, --generate-certificate
              Generate a signed certificate.

       -e, --verify-chain
              Verify a PEM encoded certificate chain.  The last certificate in
              the chain must be a self signed one.

              Generate PKCS #3 encoded Diffie-Hellman parameters.

       --load-ca-certificate FILE
              Certificate authority’s certificate file to use.

       --load-ca-privkey FILE
              Certificate authority’s private key file to use.

       --load-certificate FILE
              Certificate file to use.

       --load-privkey FILE
              Private key file to use.

       --load-request FILE
              Certificate request file to use.

       -p, --generate-privkey
              Generate a private key.

       -q, --generate-request
              Generate a PKCS #10 certificate request.

       -s, --generate-self-signed
              Generate a self-signed certificate.

       -u, --update-certificate
              Update a signed certificate.

   Controlling output
       -8, --pkcs8
              Use PKCS #8 format for private keys.

       --dsa  Generate a DSA key.

       --bits BITS
              Specify the number of bits for key generation.

              Use weak encryption algorithms.

              Use RAW/DER format for input certificates and private keys.

       --infile FILE
              Input file.

              Use RAW/DER format for output certificates and private keys.

       --outfile FILE
              Output file.

       --password PASSWORD
              Password to use.

              Generate a PKCS #12 structure.

              Use a template file to read input. See the  doc/certtool.cfg  in
              the distribution, for an example.

              Some   previous  versions  of  certtool  generated  wrongly  the
              optional parameters in a private key. This may  affect  programs
              that  used  them.  To  fix  an old private key use --key-info in
              combination with this parameter.

       --v1   When generating a certificate use the X.509  version  1  format.
              This  does  not add any extensions (such as indication for a CA)
              but some programs do need these.


       To create a private key, run:

              $ certtool --generate-privkey --outfile key.pem

       To create a certificate request (needed when the certificate is  issued
       by another party), run:

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

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

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

       To generate a certificate using the private key only, use the command:

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

       To view the certificate information, use:

              $ certtool --certificate-info --infile cert.pem

       To   generate   a  PKCS  #12  structure  using  the  previous  key  and
       certificate, use the command:

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


       Nikos    Mavroyanopoulos    <>    and    others;     see
       /usr/share/doc/gnutls-bin/AUTHORS for a complete list.

       This  manual  page  was written by Ivo Timmermans <>, for
       the Debian GNU/Linux system (but may be used by others).

                                 May 23rd 2005                     certtool(1)