NAME

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

SYNOPSIS

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

STATUS

       This documentation is still work in progress. Please contribute to the initial review in Mozilla NSS bug
       836477[1]

DESCRIPTION

       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.

OPTIONS

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

       -V
           Verifies the digital signature.

       -d directory
           Specify the database directory which contains the certificates and keys.

           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 dbm: is not
           used, then the tool assumes that the given databases are in the SQLite format.

       -a
           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.

       -v
           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 /home/my/sharednssdb

           signatureValid=yes

   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:

       •   cert8.db for certificates

       •   key3.db for keys

       •   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 performance:

       •   cert9.db for certificates

       •   key4.db for keys

       •   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 use the
       SQLite type Using the legacy databases must be manually specified by using the dbm: prefix with the given
       security directory. For example:

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

       To set the legacy database type as the default type for the tools, set the NSS_DEFAULT_DB_TYPE
       environment variable to dbm:

           export NSS_DEFAULT_DB_TYPE="dbm"

       This line can be added to the ~/.bashrc file to make the change permanent for the user.

       •   https://wiki.mozilla.org/NSS_Shared_DB_Howto

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

       •   https://wiki.mozilla.org/NSS_Shared_DB

SEE ALSO

       signtool (1)

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

       •   Setting up the shared NSS database

           https://wiki.mozilla.org/NSS_Shared_DB_Howto

       •   Engineering and technical information about the shared NSS database

           https://wiki.mozilla.org/NSS_Shared_DB

ADDITIONAL RESOURCES

       For information about NSS and other tools related to NSS (like JSS), check out the NSS project wiki at
       http://www.mozilla.org/projects/security/pki/nss/. The NSS site relates directly to NSS code changes and
       releases.

       Mailing lists: https://lists.mozilla.org/listinfo/dev-tech-crypto

       IRC: Freenode at #dogtag-pki

AUTHORS

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

       Authors: Elio Maldonado <emaldona@redhat.com>, Deon Lackey <dlackey@redhat.com>.

LICENSE

       Licensed under the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this
       file, You can obtain one at http://mozilla.org/MPL/2.0/.

NOTES

        1. Mozilla NSS bug 836477
           https://bugzilla.mozilla.org/show_bug.cgi?id=836477

nss-tools                                          19 May 2021                                        SIGNVER(1)