ovs-pki

Synopsis

Each command takes the form:

ovs-pki <options> <command> <args>...

The implemented commands and their arguments are:

  • ovs-pki init

  • ovs-pki req <name>

  • ovs-pki sign <name> [<type>]

  • ovs-pki req+sign <name> [<type>]

  • ovs-pki verify <name> [<type>]

  • ovs-pki fingerprint <file>

  • ovs-pki self-sign <name>

Each <type> above is a certificate type, either switch (default) or controller.

The available options are:

  • -k <type> or --key=<type>

  • -B <nbits> or --bits=<nbits>

  • -D <file> or --dsaparam=<file>

  • -b or --batch

  • -f or --force

  • -d <dir> or --dir=<dir>

  • -l <file> or --log=<file>

  • -u or --unique

  • -h or --help

Description

The ovs-pki program sets up and manages a public key infrastructure for use with OpenFlow. It is intended to be a simple interface for organizations that do not have an established public key infrastructure. Other PKI tools can substitute for or supplement the use of ovs-pki.

ovs-pki uses openssl(1) for certificate management and key generation.

Offline Commands

The following ovs-pki commands support manual PKI administration:

  • init

    Initializes a new PKI (by default in /var/lib/openvswitch/pki, although this default may be changed at Open vSwitch build time) and populates it with a pair of certificate authorities for controllers and switches.

    This command should ideally be run on a high-security machine separate from any OpenFlow controller or switch, called the CA machine. The files pki/controllerca/cacert.pem and pki/switchca/cacert.pem that it produces will need to be copied over to the OpenFlow switches and controllers, respectively. Their contents may safely be made public.

    By default, ovs-pki generates 2048-bit RSA keys. The -B or --bits option (see below) may be used to override the key length. The -k dsa or --key=dsa option may be used to use DSA in place of RSA. If DSA is selected, the dsaparam.pem file generated in the new PKI hierarchy must be copied to any machine on which the req command (see below) will be executed. Its contents may safely be made public.

    Other files generated by init may remain on the CA machine. The files pki/controllerca/private/cakey.pem and pki/switchca/private/cakey.pem have particularly sensitive contents that should not be exposed.

  • req <name>

    Generates a new private key named <name>-privkey.pem and corresponding certificate request named <name>-req.pem. The private key can be intended for use by a switch or a controller.

    This command should ideally be run on the switch or controller that will use the private key to identify itself. The file <name>-req.pem must be copied to the CA machine for signing with the sign command (below).

    This command will output a fingerprint to stdout as its final step. Write down the fingerprint and take it to the CA machine before continuing with the sign step.

    When RSA keys are in use (as is the default), req, unlike the rest of the ovs-pki commands, does not need access to a PKI hierarchy created by ovs-pki init. The -B or --bits option (see below) may be used to specify the number of bits in the generated RSA key.

    When DSA keys are used (as specified with --key=dsa), req needs access to the dsaparam.pem file created as part of the PKI hierarchy (but not to other files in that tree). By default, ovs-pki looks for this file in the PKI directory as dsaparam.pem, but the -D or --dsaparam option (see below) may be used to specify an alternate location.

    <name>-privkey.pem has sensitive contents that should not be exposed. <name>-req.pem may be safely made public.

  • sign <name> [<type>]

    Signs the certificate request named <name>-req.pem that was produced in the previous step, producing a certificate named <name>-cert.pem. <type>, either switch (default) or controller, indicates the use for which the key is being certified.

    This command must be run on the CA machine.

    The command will output a fingerprint to stdout and request that you verify that it is the same fingerprint output by the req command. This ensures that the request being signed is the same one produced by req. (The -b or --batch option suppresses the verification step.)

    The file <name>-cert.pem will need to be copied back to the switch or controller for which it is intended. Its contents may safely be made public.

  • req+sign <name> [<type>]

    Combines the req and sign commands into a single step, outputting all the files produced by each. The <name>-privkey.pem and <name>-cert.pem files must be copied securely to the switch or controller. <name>-privkey.pem has sensitive contents and must not be exposed in transit. Afterward, it should be deleted from the CA machine.

    This combined method is, theoretically, less secure than the individual steps performed separately on two different machines, because there is additional potential for exposure of the private key. However, it is also more convenient.

  • verify <name> [<type>]

    Verifies that <name>-cert.pem is a valid certificate for the given <type> of use, either switch (default) or controller. If the certificate is valid for this use, it prints the message <name>-cert.pem: OK; otherwise, it prints an error message.

  • fingerprint <file>

    Prints the fingerprint for <file>. If <file> is a certificate, then this is the SHA-1 digest of the DER encoded version of the certificate; otherwise, it is the SHA-1 digest of the entire file.

  • self-sign <name>

    Signs the certificate request named <name>-req.pem using the private key <name>-privkey.pem, producing a self-signed certificate named <name>-cert.pem. The input files should have been produced with ovs-pki req.

    Some controllers accept such self-signed certificates.

Options

  • -k <type> or --key=<type>

    For the init command, sets the public key algorithm to use for the new PKI hierarchy. For the req and req+sign commands, sets the public key algorithm to use for the key to be generated, which must match the value specified on init. With other commands, the value has no effect.

    The <type> may be rsa (the default) or dsa.

  • -B <nbits> or --bits=<nbits>

    Sets the number of bits in the key to be generated. When RSA keys are in use, this option affects only the init, req, and req+sign commands, and the same value should be given each time. With DSA keys are in use, this option affects only the init command.

    The value must be at least 1024. The default is 2048.

  • -D <file> or --dsaparam=<file>

    Specifies an alternate location for the dsaparam.pem file required by the req and req+sign commands. This option affects only these commands, and only when DSA keys are used.

    The default is dsaparam.pem under the PKI hierarchy.

  • -b or --batch

    Suppresses the interactive verification of fingerprints that the sign command by default requires.

  • -d <dir> or --dir=<dir>

    Specifies the location of the PKI hierarchy to be used or created by the command. All commands, except req, need access to a PKI hierarchy.

    The default PKI hierarchy is /var/lib/openvswitch/pki, although this default may be changed at Open vSwitch build time

  • -f or --force

    By default, ovs-pki will not overwrite existing files or directories. This option overrides this behavior.

  • -l <file> or --log=<file>

    Sets the log file to <file>. The default is ovs-pki.log in the OVS log directory. The default OVS log directory is /var/log/openvswitch, although this default may be changed at Open vSwitch build time.

  • -u or --unique

    Changes the format of the certificate’s Common Name (CN) field. By default, this field has the format <name> id:<uuid-or-date>. This option causes the provided name to be treated as unique and changes the format of the CN field to be simply <name>.

  • -h or --help

    Prints a help usage message and exits.