swverify(8)

Contents

NAME

       swverify -- Verify Software

SYNOPSIS

       Posix:

       swverify  [-d|-r]  [-F]  [-f file]  [-t targetfile] \
       [-x option=value]  [-X options_file]  [-W option] \
       [software_selections]  [@targets]

       swverify  # Verify standard input

       swverify selection [@ target] # Verify Installed Software

       swverify -d [@ target]

       swverify -d @-   # dash means standard input

       swverify [--scm|--order-files] -d @.  # . means current directory

       swverify [--scm|--order-files] -d @:package_directory

       Implementation Extension:

       swverify [-Wd] -Wemit-digest-file [portable_archive_file]

       swverify [-Wd] -Wemit-signed-file [portable_archive_file]

       swverify [-Wd] [-Wsha1] -Wemit-digest-file [portable_archive_file]

       swverify [-Wd] -Wget-sig-if=sigfilename [portable_archive_file]

DESCRIPTION

       The swverify utility checks the accuracy of software in distributions
       and installed_software.  If no options are given, a serial distribution
       on stdin is verified.

       Currently, swverify does not read the defaults files.  "/" is the
       default target for installed software.  Stdin is the default target for
       distributions.  The built-in value of "installed_software_catalog" is
       "var/lib/swbis/catalog".

OPTIONS

       -d

              Specify to operate on a distribution rather than installed
              software.

       -r

              Specify that target is an alternate root target. (Not currently
              used)



       software_selections

              See other man pages.


       targets

              See other man pages.  Currently, only one (1) target can be
              specified.


       -x option=value

              Specify the extended option overriding the defaults file value.
              This option not yet implemented.

       -X FILE

              Specify the extended options filename, FILE,  overriding the
              default filename.  This option not yet implemented.

       Other POSIX options not implemented.

POSIX EXTENDED OPTIONS

       Not yet implemented.

IMPLEMENTATION EXTENSION OPTIONS

       -W option[,option,...]

              Specify the implementation extension option.
              Syntax: -W option[=option_argument[,option...]
              Options may be separated by a comma.

       --checksig | -W checksig

              This is the default action and is the same as the POSIX syntax
              "-d @target".  If target file is not a directory then verify
              archive md5 and sha1 and gpg signature directly from the file.
              If target file is a directory, attempt to verify the signature
              using GNU tar and gpg and if successful execute the distributor
              extension script checksig.  If checksig does not exist then exit
              with failure.
              FILE may be "." (current directory) or "-" (standard input).  A
              serial archive file may be compressed with gzip, bzip2, or Unix
              compress.


       --order-catalog

              Use the order of files in catalog/dfiles/files to recreate the
              signed data when verifying the directory (unpacked tarball) form
              of the package.


       --cvs

              Read and process information in the ./catalog (before it is
              authenticated) to correct the file sytem meta-data in an attempt
              to verify the GPG signature.  It only affects verification on
              the directory (unpacked tarball), not tarball verification.  It
              is required when verifying an exported or working SCM (Source
              Code Management, such as CVS) directory if the SCM does not
              preserve and restore file system meta-data.  This option also
              emliminates the dependency on the order of files in file system
              directories.


       --scm

              Currently, same as the --cvs option.


       --no-checkdigest

              When verifying the directory form, do not run the checkdigest
              script even if the GPG signed data contains the checkdigest
              script.


       --signed-file  [FILE]

              Write the GPG signed portion of the package to stdout without
              verifying it.  Read archive file FILE or standard input and
              write the signed file (i.e. gpg's signed stuff) to stdout.  This
              is the catalog section of the Posix package.  This option is
              supported for the tarball file and unpacked tarball directory.
              Use of the --scm option may be required for the unpacked tarball
              directory form.


       --digest-file  [FILE]

              Write the payload portion of the package to stdout without
              verifying its digest matches the digest in the signed data.
              This is the storage section of the Posix package.  This option
              is not supported for the unpacked tarball form.


       -W emit-signed-file | -W C

              Same as --signed-data.  Also the same as -WC


       -W emit-digest-file [FILE]

              Same as --digest-data.  Also the same as -WS


       -W show-auth-files | -W d

              Writes the relevent security file to stderr.  Applies to emit-
              digest-file and emit-signed-file modes.


       -W sig-number=N

              Operates on the Nth signature, 0 is last, 1 is the first.


       -W get-sig-if=outputfile

              Verifies the archive digests by comparing to the digests in the
              catalog and if they match write the sigfile to outputfile and
              the signed data to stdout.

DISTRIBUTOR SCRIPTS

       Not yet implemented.

IMPLEMENTATION EXTENSION DISTRIBUTOR SCRIPTS

   checkdigest <path>/catalog/<dfiles>/checkdigest
       This script was named 'checksig'.  As of 2006-03-28, the name of this
       script should be 'checkdigest'.  The name 'checksig' should be
       considered deprecated for new packages.

       A software distributor may choose to provide a checkdigest script.  The
       checkdigest  script is part of the distribution object.  It is used to
       verify the directory form of a distribution  (as distinguished from
       installed_software).  The verified attributes are the same as those
       verified from the archive file form with the addition of the
       distribution file list.  In addition the script may chose to verify the
       adjunct_md5sum and file.md5 digests and symbolic links.  Due to the
       constraints of reproducing the archive message digests from the
       directory, which include tar utility dependence and file owner/group
       specification, this script may not be useful to all distributors.

   Execution Environment
        The script may require the SW_CONTROL_TAG environment variable be set
       to "checkdigest" or "checkfile" and if not exit with failure.  swverify
       will set this variable to "checkfile" if the --scm or --cvs option is
       used, and otherwise to "checkdigest".  The script may take different
       action based on the value.  Currently, the checkdigest script used by
       the swbis source package will omit the archive digests checks if set to
       SW_CONTROL_TAG="checkfile" since reproducing the archive digest is not
       possible when the package is exported from CVS due to file system meta-
       data non-preservation. In this case the file list is checked and the
       md5 and sha1 digests are verified for each regular file.

VERIFYING SIGNATURES

       The design separates the payload and catalog, therefore, verification
       requires verifying the storage section md5 and sha1 message digests and
       then verifying the signature of the catalog.  Naturally, it is required
       that the signed data include the storage section message digests and
       that they match the storage sections.  The storage section digests are
       stored as separate attribute files in the dfiles catalog directory.

       The checksig (i.e. swverify -d @-) mode verifies a tarballs embedded
       signature.  This mode checks all the security files in the package and
       is the preferred way to authenticate a package.  The emit-signed-file,
       emit-digest-file modes are useful for testing, sanity checks and custom
       applications.  The get-sig-if is the function used when verifying a
       tarball.

   Verifying a POSIX Distribution Archive Manually
       The design of the authentication attributes supports manual
       verification of the archive file (e.g. tarball) form of the
       distribution, that is verification take place on the uncompressed
       archive using 'gpg', GNU 'tar' and the swbis utility 'swverify' (or the
       library utility 'arf2arf').

       The authentication requires the following steps:

       1) Obtain the signature from the package.
       2) Recreate the signed data and present this byte stream and
          the signature to GNU privacy guard (gpg) for authentication.
       3) Obtain the message digest (md5, sha1,) contained in the
          control file in the authenticated archive byte stream.
       4) Recreate the digest byte stream and present to the appropriate
          hash generation program to generate the message digest.
       5) Compare the digest message generated in step 4 to the
          authenicated digest obtained in step 3.

        1) Obtain the signature from the package.

         #!/bin/sh
         tar zxf - -O \*/catalog/dfiles/signature < swbis-0.460.tar.gz


       2)  Recreate the signed data

         #!/bin/sh
         swverify -WC < swbis-0.460.tar.gz | gpg --verify /dev/tty -
         # Cut and paste the signature file obtained in step 1


       3)  Obtain the message digest

         #!/bin/sh
         swverify -WC < swbis-0.460.tar.gz | \
         tar xf - -O \*/catalog/dfiles/md5sum


       4)  Create the digested byte stream

         #!/bin/sh
         swverify -WS < swbis-0.460.tar.gz | md5sum


   Verifying a POSIX Distribution Directory Manually
       Verifying the unpacked tarball package form.

       The design of the authentication attributes supports manual
       verification of the directory (unpacked) form of the distribution, that
       is verification takes place on the leading package directory and its
       contents. It should be noted that it is left to the user to verify that
       the archive installed no files outside of this directory as this would
       likely indicate a trojan'ed package.

       If authenticating on a GNU/Linux system using GNU tar it is possible to
       validate the archive message digests and signature if the following are
       true:


       1) The package file is a tar archive.
       2) The installed version of GNU tar produces archives with
          bit-for-bit sameness relative to the swpackage(8) utility
          that generated the signature and message digests.  For packages
          made with swbis versions >= 0.474 and with format option "ustar"
          you will need GNU tar 1.14 or 1.15.*
       3) The package has a single leading package directory, like a source
          package.
       4) The package catalog contains the 'checkdigest' script.
       5) The package catalog contains the distribution file list.
       6) The ownership names are present and have the same uid's and gid's.
       7) The package was unpacked with a version of tar that
          preserves all file times.  Use for example "tar xpf".


       In this example, the package has a single path name prefix called,
       namedir and the file owner/group are root.  These restrictions are
       suited to source packages.
        Verify the signature:

         #!/bin/sh
         tar cf - -b1 --owner=root --group=root \
         --exclude=namedir/catalog/dfiles/signature  \
         namedir/catalog | gpg --verify namedir/catalog/dfiles/signature -

       If this fails try using GNU tar option --posix.  If this fails then,
       try experimenting with the owner, group, and numeric-id options.  If
       you are unable to verify a tar byte stream using gpg(1) that contains
       the storage section message digests, then the package cannot be
       authenticated.


       Assuming you successfully verified the catalog as shown above, now
       generate the message digest and compare it to the md5sum file attribute
       from the same byte stream that gpg(1) claims is authenticate.

         #!/bin/sh
         grep -v namedir/catalog  namedir/catalog/dfiles/files | \
         tar cf - -b1 --owner=root --group=root \
         --files-from=- --no-recursion | md5sum

         tar cf - -b1 --owner=root --group=root \
         --exclude=namedir/catalog/dfiles/signature  \
         namedir/catalog | tar xf - -O  namedir/catalog/dfiles/md5sum

       Likewise for the sha1 digest.

       If the package has symbolic links, Verify the adjunct_md5sum:

         #!/bin/sh
         grep -v namedir/catalog  namedir/catalog/dfiles/files | \
         ( while read file; do if [ ! -h $file ]; then echo $file; fi done; )|\
         tar cf - -b1 --owner=root --group=root \
         --files-from=- --no-recursion | md5sum
         cat namedir/catalog/dfiles/adjunct_md5sum

       The symbolic link files must be verified manually by comparing to the
       INFO file information.

   Verifying a POSIX distribution in tar format
       Below is output from successful authentication.  The authentication
       requires checking the archive md5 message digest (and sha1 if present).
       All present message digests must succeed and if this is true then the
       signed file is written and gpg proceeds to check the signature.  If the
       sig_header file is present then the requirement that its data be
       identical to the ustar header of every signature file is enforced.  If
       any one of these checks fails, authentication fails.

          #!/bin/sh
          swverify --checksig mypackage-00.1.tar.gz
               # - or -
          swverify -d @- < mypackage-00.1.tar.gz


       gpg: /home/userx/.gnupg/options:82: deprecated option "honor-http-proxy"
       gpg: please use "keyserver-options honor-http-proxy" instead
       gpg: WARNING: using insecure memory!
       gpg: please see http://www.gnupg.org/faq.html for more information
       swbis: Archive digest: md5 OK (Good)
       swbis: Archive digest: sha1 OK (Good)
       gpg: Signature made Sun Mar 16 20:28:23 2003 EST using DSA key ID 82B0DBE4
       gpg: Good signature from "Test User (pass=Iforgot) localhost>"
       Primary key fingerprint: 77BB A98E B3A2 ED4C 217E  8A25 2BF4 28AB 82D0 DDE4


   Verifying the Directory Form of a Distribution
       Authenticating using 'swverify' is subject to the same constraints as
       verifying manually using GNU tools because swverify implements this
       using GNU tools.

       'swverify' when verifying the directory form of a distribution attempts
       to authenticate the exported catalog signature.  If it is successful it
       executes the 'checkdigest' script found in the 'catalog/dfiles'
       directory of the exported catalog.  If the 'checkdigest' script does
       not exist, authentication fails. 'swverify' will only attempt to run
       the 'checkdigest' script if it is found in the dfiles directory of an
       authenticated catalog.

       'swverify' currently has no provision to verify the archive section
       (i.e. the file storage structure) of a directory (unpacked) form of a
       POSIX distribution.  It is the role of the checkdigest script to do
       this.

       For example, if filemypackage-00.1 is a directory unpacked with a tar
       reading utility that preserved file times then try,


          #!/bin/sh
          swverify --checksig mypackage-00.1

        or change directory into mypackage-00.1 and use the POSIX syntax:

          swverify -d @.



          swverify -d @`pwd`/mypackage-00.1

        Below is example output of a package with a 'checksig' script.


       swverify: Attempting to verify using --posix tar option.
       gpg: /home/userx/.gnupg/options:82: deprecated option "honor-http-proxy"
       gpg: please use "keyserver-options honor-http-proxy" instead
       gpg: WARNING: using insecure memory!
       gpg: please see http://www.gnupg.org/faq.html for more information
       gpg: Signature made Sun Mar 16 21:00:54 2003 EST using DSA key ID 82B0DBE4
       gpg: BAD signature from "Test User (pass=Iforgot) localhost>"
       swverify: First attempt failed.
       swverify: Attempting to verify without using --posix tar option.
       gpg: /home/jhl/.gnupg/options:82: deprecated option "honor-http-proxy"
       gpg: please use "keyserver-options honor-http-proxy" instead
       gpg: WARNING: using insecure memory!
       gpg: please see http://www.gnupg.org/faq.html for more information
       gpg: Signature made Sun Mar 16 21:00:54 2003 EST using DSA key ID 82B0DBE4
       gpg: Good signature from "Test User (pass=Iforgot) localhost>"
       gpg: WARNING: This key is not certified with a trusted signature!
       gpg:          There is no indication that the signature belongs to the owner.
       Primary key fingerprint: 77BB A98E B3A2 ED4C 217E  8A25 2BF4 28AB 82D0 DDE4
       swverify: GPG signature verified.
       swverify: Got it!
       swverify: The vendor extension script checksig can now be executed.
       checksig: Checking files OK (Good)
       checksig: Checking Archive md5 OK (Good)
       checksig: Checking Archive sha1 OK (Good)
       gpg: /home/userx/.gnupg/options:82: deprecated option "honor-http-proxy"
       gpg: please use "keyserver-options honor-http-proxy" instead
       gpg: WARNING: using insecure memory!
       gpg: please see http://www.gnupg.org/faq.html for more information
       gpg: Signature made Sun Mar 16 21:00:54 2003 EST using DSA key ID 82B0DBE4
       gpg: Good signature from "Test User (pass=Iforgot) localhost>"
       gpg: WARNING: This key is not certified with a trusted signature!
       gpg:          There is no indication that the signature belongs to the owner.
       Primary key fingerprint: 77BB A98E B3A2 ED4C 217E  8A25 2BF4 28AB 82D0 DDE4
       checksig: Signature proper OK (Good)
       checksig: /usr/bin/gpg exit status : 0



   Verifying Installed Software
       (This capability is only partially implemented.)  Verifying Installed
       Software involves comparing the package meta-data to the live file
       system.  The validity of a successful comparison depends on the
       validity of the installed software catalog.  swverify makes no attempt
       to check the validity of the entire catalog, however, it can use the
       distribution GPG signature, which is stored in the catalog, to
       authenticate the meta-data of the selected package.

       Below is an example. Note, the package is selected on the basis of its
       product or bundle tag.

       $ swverify -r your_product_tag @ /
       swverify: verifying installed software at:
       swverify: //var/lib/swbis/catalog/swbis/your_product_tag/0.000/0
       gpg: WARNING: --honor-http-proxy is a deprecated option.
       gpg: please use "--keyserver-options honor-http-proxy" instead
       gpg: Signature made Fri Feb 20 00:21:00 2004 EST using DSA key ID 82B0DBE4
       gpg: Good signature from "Test User (pass=Iforgot) localhost>"
       Fingerprint: 77BB B98D A3A2 ED4C 217E  9A25 8BF4 05AB 82B0 DBE4
       swverify: Warning: file checks not implemented
       swverify: signature verification return status=0



   Create the digest byte stream -Wemit-digest-file mode:
       Here are some examples that verify the archive digests.


          #!/bin/sh
          cat your-tarball | swverify -Wd -WS | md5sum


       Your should see a pair of identical digests. Use the -Wsha1 option to
       check the sha1 digest in a similar manner.

       ** IMPORTANT **
       This does not mean that the data is authenticate in the sense of being
       attributable to a person, merely that the md5sum attribute and the
       payload byte stream match.

       To inspect the digested data, try:

         #!/bin/sh
         cat your-tarball | swverify -WS | tar tvf -


   Create the signed byte stream -Wemit-signed-file mode:
       Here is an example which allows inspection of the signed file.


         cat your-tarball | swverify -WC | tar tvf -


   -Wget-sig-if mode:
       This is the mode that is used internally when verifying a tarball.
       Below is an example of using this mode manually.


         #!/bin/sh
         cat your-tarball | swverify -Wget-sig-if=/dev/tty | \
         gpg --verify  /dev/tty -


       Now try to copy and paste the sigfile and gpg should attempt to verify
       the signature.

              Note:  This verifies the md5 or sha1 digests before writing the
              signed data to stdout.  If the sha1 or md5 match fails then an
              empty file is written to stdout.

EXAMPLES

       Examples of verifying distributions and installed software.

   Distribution Verification
       * Verify a tar archive

         swverify -d < foo-1.1.tar.gz
                  or
         swverify -d @`pwd`/foo-1.1.tar.gz
                  or
         swverify -d @:foo-1.1.tar.gz
                  or
         cat foo-1.1.tar.gz | swverify -d @-

                 Note: --checksig and '-d' perform the same operations.


       * Verify a unpacked distribution

         swverify -d @`pwd`/foo-1.1
                  or
         cd foo-1.1; swverify -d @.
                  or
         swverify -d @:foo-1.1

                 Note: --checksig and '-d' perform the same operations.


       * Verify an exported SCM Directory

         # This is the same as directory verification except the '--cvs' option is needed.


   Installed Software Verification
       * Verify installed software

         swverify foo.foo @/tmp/test
                  or
         swverify foo.foo  # at default target

RETURN VALUE

       Exit status of the checksig script or gpg utility for --checksig
       directory operation.  0 if successful on all targets, 1 if failed on
       all targets, 2 if failed on some targets.

FILES

       /var/lib/swbis/catalog # Location of installed catalog
       /usr/lib/swbis/swdefaults
       /usr/lib/swbis/swbisdefaults
       $HOME/.swbis/swdefaults
       $HOME/.swbis/swbisdefaults

APPLICABLE STANDARDS

       IEEE Std 1387.2-1995 (ISO/IEC 15068-2:1999), Open Group CAE C701.

SEE ALSO

       info swbis


       sw(5), swign(1), swpackage(8), gpg(1), libexec/swbis/arf2arf


IDENTIFICATION

        swverify: The verification utility of the swbis project.
        Author: James Lowe, Jr.   Email: jhlowe at acm.org
        Version: 1.6
        Last Updated: 2010-02-04
        Copying: GNU Free Documentation License

BUGS

       The signature file's archive header (or data) is not part of the signed
       data therefore it may be subject to undetectable tampering, however,
       swverify does perform sanity checks on the pathname, permissions and
       filetype if the sig_header file (See sw(5) manual page.) is not present
       [due to being signed by a old swpackage version], and if sig_header is
       present, swverify requires that it match the sig file header.  The
       ability to verify the unpacked directory form of the package depends on
       many factors not immediately obvious, among them are the tar header
       uname and gname, and whether they are preserved by the reading utility,
       and whether these names are in the system database files /etc/passwd
       and /etc/group, and if so, whether they assign the same uid/gid as the
       package.

       Verification of the directory form of a distribution (i.e. the
       installed tarball path name prefix) such as running 'swverify -d @.'
       after running 'swign @.' will fail if the order of directory entries is
       not compatible with traditional Unix file system directory entry
       ordering, which is the order of file creation.  This ordering is almost
       always apparent on Ext2 file system for small directories (but not
       always for big directories).  Ext3, reiserFS, and DarwinOS et.al file
       systems do not have this ordering, use of the '--order-catalog' option
       is therefore required.  Use of the '--cvs' or '--order-catalog' options
       is theoretically problematic because it causes the use and
       interpretation of data in the verification of that same data therefore
       opening possible attack vectors.



                                                                   swverify(8)