(mozilla-projects-nss-tools-signver)=

# NSS tools : signver

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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]

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 [sql:]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 sql:

is not used, then the tool assumes that the given databases are in

the old 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 sql:/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:

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

performance:

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

permanent.

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:

o

<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:

o

<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.

o Setting up the shared NSS database

<https://wiki.mozilla.org/NSS_Shared_DB_Howto>

o 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

[1]

[http://www.mozilla.org/projects/security/pki/nss/](https://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, and Sun.

Authors: Elio Maldonado \<

<mailto:emaldona@redhat.com>

>, Deon Lackey

\<

<mailto:dlackey@redhat.com>

>.

Copyright

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

References

Visible links

1.

[http://www.mozilla.org/projects/security/pki/nss/](https://www.mozilla.org/projects/security/pki/nss/)
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