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       debsig-verify - Verify signatures for a Debian format package


       debsig-verify [options] <deb>


       This  program  is part of a security model that verifies the source and
       validity of a Debian format package (commonly refered to as a deb).

       This program implements the verification specs defined in the document,
       "Package  Verification  with  dpkg:  Implementation",  which  is a more
       complete reference for the verification procedure.

       The program generally takes one argument, the deb file to be  verified.
       It will then check the origin signature of the deb, find its Public Key
       ID (long format), and use that as the name for a  policy  subdirectory.
       If  this  subdirectory  does  not  exist,  then  the verification fails

       In this subdirectory, the program finds one or more  files  named  with
       the   .pol  file  extension,  which  signifies  an  XML  format  policy
       definition. This file contains three main parts.

       Origin Information about the origin of this policy.

              Rules used to decide if this policy is pertinent to  this  deb’s

              Rules that are used to actually verify the deb.

       The  policy files will reference keyrings by a filename. These keyrings
       will be looked for in a subdirectory  of  the  keyring  directory.  The
       subdirectory  has  the same name as the policy subdirectory (previously
       determined by the Origin’s Public Key ID).

       The program will, after first parsing the entire file, check the Origin
       ID  against  the  Public Key ID of the origin signature in the deb.  If
       these match (which they should, else something is really  wrong),  then
       it will proceed to the Selection rules.

       The  Selection  rules  decide  whether  this  policy  is  suitable  for
       verifying this deb. If these rules fail, then the program will  proceed
       to  the  next  policy.  If it passes, then the program commits to using
       this policy for verification, and no other policies will be referenced.

       The  last verification step relies on the Verification rules. These are
       similar in  format  to  the  Selection  rules,  but  are  usually  more
       constrained.  If  these  rules  fail, the program exits with a non-zero
       status. If they pass, then it exits with a zero status.


       -q     Causes the program to send no output, other than  fatal  errors.
              This is useful when being called from another program, where you
              rely on the exit value only.

       -v     Causes the program to send more output on execution,  so  as  to
              follow the steps it is taking while trying to verify the deb.

       -d     Outputs  even  more  info than the -v option. This is mainly for

              Outputs the version information for the program.  This  includes
              the  policy  format  version.  This  option does not require any
              other arguments.

              Outputs a list of the policies that passed the  Selection  phase
              of  the  verification  process. In other words, those that could
              potentially verify the deb. The output is one line  showing  the
              directory  selected  by  the origin signature, and then a single
              line for any policy  files  in  that  directory  that  pass  the
              Selection rules. This option will NOT verify the deb.

       --use-policy <pol>
              This  option takes one argument, which is the name of the policy
              file (as shown by the --list-policies  option).  Note,  this  is
              just  a file, and not a full path. You cannot specifiy arbitrary
              policies.  This option is useful if more than one policy applies
              to potentially verifying the deb. The program will then use this
              policy, and only this policy, to try and verify the deb.


              Directory containing the policy (.pol) definitions.

              XML format policy files.

              Directory  containing  the  keyrings  that  coincide  with   the

              GPG format keyrings for use by the policies.




       Ben Collins <>