MDN’s new design is in Beta! A sneak peek:

NSS tools : signver


   signver — Verify a detached PKCS#7 signature for a file.


   signtool -A | -V -d directory [-a] [-i input_file] [-o output_file] [-s
   signature_file] [-v]


   The Signature Verification Tool, signver, is a simple command-line utility
   that unpacks a base-64-encoded PKCS#7 signed object and verifies the
   digital signature using standard cryptographic techniques. The Signature
   Verification Tool can also display the contents of the signed object.



           Displays all of the information in the PKCS#7 signature.


           Verifies the digital signature.

   -d [sql:]directory

           Specify the database directory which contains the certificates and

           signver supports two types of databases: the legacy security
           databases (cert8.db, key3.db, and secmod.db) and new SQLite
           databases (cert9.db, key4.db, and pkcs11.txt). If the prefix sql:
           is not used, then the tool assumes that the given databases are in
           the old format.


           Sets that the given signature file is in ASCII format.

   -i input_file

           Gives the input file for the object with signed data.

   -o output_file

           Gives the output file to which to write the results.

   -s signature_file

           Gives the input file for the digital signature.


           Enables verbose output.

Extended Examples

  Verifying a Signature

   The -V option verifies that the signature in a given signature file is
   valid when used to sign the given object (from the input file).

 signver -V -s signature_file -i signed_file -d sql:/home/my/sharednssdb


  Printing Signature Data

   The -A option prints all of the information contained in a signature file.
   Using the -o option prints the signature file information to the given
   output file rather than stdout.

 signver -A -s signature_file -o output_file

NSS Database Types

   NSS originally used BerkeleyDB databases to store security information.
   The last versions of these legacy databases are:

     o cert8.db for certificates

     o key3.db for keys

     o secmod.db for PKCS #11 module information

   BerkeleyDB has performance limitations, though, which prevent it from
   being easily used by multiple applications simultaneously. NSS has some
   flexibility that allows applications to use their own, independent
   database engine while keeping a shared database and working around the
   access issues. Still, NSS requires more flexibility to provide a truly
   shared security database.

   In 2009, NSS introduced a new set of databases that are SQLite databases
   rather than BerkleyDB. These new databases provide more accessibility and

     o cert9.db for certificates

     o key4.db for keys

     o pkcs11.txt, which is listing of all of the PKCS #11 modules contained
       in a new subdirectory in the security databases directory

   Because the SQLite databases are designed to be shared, these are the
   shared database type. The shared database type is preferred; the legacy
   format is included for backward compatibility.

   By default, the tools (certutil, pk12util, modutil) assume that the given
   security databases follow the more common legacy type. Using the SQLite
   databases must be manually specified by using the sql: prefix with the
   given security directory. For example:

 # signver -A -s signature -d sql:/home/my/sharednssdb

   To set the shared database type as the default type for the tools, set the
   NSS_DEFAULT_DB_TYPE environment variable to sql:

 export NSS_DEFAULT_DB_TYPE="sql"

   This line can be set added to the ~/.bashrc file to make the change

   Most applications do not use the shared database by default, but they can
   be configured to use them. For example, this how-to article covers how to
   configure Firefox and Thunderbird to use the new shared NSS databases:


   For an engineering draft on the changes in the shared NSS databases, see
   the NSS project wiki:


See Also

   signtool (1)

   The NSS wiki has information on the new database design and how to
   configure applications to use it.

     o Setting up the shared NSS database

     o Engineering and technical information about the shared NSS database

Additional Resources

   For information about NSS and other tools related to NSS (like JSS), check
   out the NSS project wiki at
   [1] The NSS site relates
   directly to NSS code changes and releases.

   Mailing lists:

   IRC: Freenode at #dogtag-pki


   The NSS tools were written and maintained by developers with Netscape, Red
   Hat, and Sun.

   Authors: Elio Maldonado <>, Deon Lackey


   (c) 2010, Red Hat, Inc. Licensed under the GNU Public License version 2.


   Visible links

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