openssl/README-FIPS.md

OpenSSL FIPS support

This release of OpenSSL includes a cryptographic module that can be FIPS validated. The module is implemented as an OpenSSL provider. A provider is essentially a dynamically loadable module which implements cryptographic algorithms, see the README-PROVIDERS file for further details.

A cryptographic module is only FIPS validated after it has gone through the complex FIPS 140 validation process. As this process takes a very long time, it is not possible to validate every minor release of OpenSSL. If you need a FIPS validated module then you must ONLY generate a FIPS provider using OpenSSL versions that have valid FIPS certificates. A FIPS certificate contains a link to a Security Policy, and you MUST follow the instructions in the Security Policy in order to be FIPS compliant. See https://www.openssl.org/source/ for information related to OpenSSL FIPS certificates and Security Policies.

Newer OpenSSL Releases that include security or bug fixes can be used to build all other components (such as the core APIs, TLS and the default, base and legacy providers) without any restrictions, but the FIPS provider must be built as specified in the Security Policy (normally with a different version of the source code).

The OpenSSL FIPS provider is a shared library called fips.so (on Unix), or resp. fips.dll (on Windows). The FIPS provider does not get built and installed automatically. To enable it, you need to configure OpenSSL using the enable-fips option.

Installing the FIPS provider

In order to be FIPS compliant you must only use FIPS validated source code. Refer to https://www.openssl.org/source/ for information related to which versions are FIPS validated. The instructions given below build OpenSSL just using the FIPS validated source code. Any FIPS validated version may be used with any other openssl library. Please see https://www.openssl.org/source/ To determine which FIPS validated library version may be appropriate for you.

If you want to use a validated FIPS provider, but also want to use the latest OpenSSL release to build everything else, then refer to the next section.

The following is only a guide. Please read the Security Policy for up to date installation instructions.

If the FIPS provider is enabled, it gets installed automatically during the normal installation process. Simply follow the normal procedure (configure, make, make test, make install) as described in the INSTALL file.

For example, on Unix the final command

$ make install

effectively executes the following install targets

$ make install_sw
$ make install_ssldirs
$ make install_docs
$ make install_fips     # for `enable-fips` only

The install_fips make target can also be invoked explicitly to install the FIPS provider independently, without installing the rest of OpenSSL.

The Installation of the FIPS provider consists of two steps. In the first step, the shared library is copied to its installed location, which by default is

/usr/local/lib/ossl-modules/fips.so                  on Unix, and
C:\Program Files\OpenSSL\lib\ossl-modules\fips.dll   on Windows.

In the second step, the openssl fipsinstall command is executed, which completes the installation by doing the following two things:

• Runs the FIPS module self tests
• Generates the so-called FIPS module configuration file containing information about the module such as the module checksum (and for OpenSSL 3.1.2 the self test status).

The FIPS module must have the self tests run, and the FIPS module config file output generated on every machine that it is to be used on. For OpenSSL 3.1.2 you must not copy the FIPS module config file output data from one machine to another.

On Unix, the openssl fipsinstall command will be invoked as follows by default:

$ openssl fipsinstall -out /usr/local/ssl/fipsmodule.cnf -module /usr/local/lib/ossl-modules/fips.so

If you configured OpenSSL to be installed to a different location, the paths will vary accordingly. In the rare case that you need to install the fipsmodule.cnf to a non-standard location, you can execute the openssl fipsinstall command manually.

Installing the FIPS provider and using it with the latest release

This normally requires you to download 2 copies of the OpenSSL source code.

Download and build a validated FIPS provider

Refer to https://www.openssl.org/source/ for information related to which versions are FIPS validated. For this example we use OpenSSL 3.1.2.

$ wget https://www.openssl.org/source/openssl-3.1.2.tar.gz
$ tar -xf openssl-3.1.2.tar.gz
$ cd openssl-3.1.2
$ ./Configure enable-fips
$ make
$ cd ..

Download and build the latest release of OpenSSL

We use OpenSSL 3.5.0 here, (but you could also use the latest 3.5.X)

$ wget https://www.openssl.org/source/openssl-3.5.0.tar.gz
$ tar -xf openssl-3.5.0.tar.gz
$ cd openssl-3.5.0
$ ./Configure enable-fips
$ make

Use the OpenSSL FIPS provider for testing

We do this by replacing the artifact for the OpenSSL 3.5.0 FIPS provider. Note that the OpenSSL 3.5.0 FIPS provider has not been validated so it must not be used for FIPS purposes.

$ cp ../openssl-3.1.2/providers/fips.so providers/.
$ cp ../openssl-3.1.2/providers/fipsmodule.cnf providers/.
// Note that for OpenSSL 3.1.2 that the `fipsmodule.cnf` file should not
// be copied across multiple machines if it contains an entry for
// `install-status`. (Otherwise the self tests would be skipped).

// Validate the output of the following to make sure we are using the
// OpenSSL 3.1.2 FIPS provider
$ ./util/wrap.pl -fips apps/openssl list -provider-path providers \
-provider fips -providers

// Now run the current tests using the OpenSSL 3.1.2 FIPS provider.
$ make tests

Copy the FIPS provider artifacts (fips.so & fipsmodule.cnf) to known locations

$ cd ../openssl-3.1.2
$ sudo make install_fips

Check that the correct FIPS provider is being used

$ cd ../openssl-3.5.0
$./util/wrap.pl -fips apps/openssl list -provider-path providers \
-provider fips -providers

// This should produce the following output
Providers:
  base
    name: OpenSSL Base Provider
    version: 3.5.0
    status: active
  fips
    name: OpenSSL FIPS Provider
    version: 3.1.2
    status: active

Using the FIPS Module in applications

Documentation about using the FIPS module is available on the fips_module(7) manual page.

Entropy Source

The FIPS provider typically relies on an external entropy source, specified during OpenSSL build configuration (default: os). However, by enabling the enable-fips-jitter option during configuration, an internal jitter entropy source will be used instead. Note that this will cause the FIPS provider to operate in a non-compliant mode unless an entropy assessment ESV and validation through the CMVP are additionally conducted.

Note that the enable-fips-jitter option is only available in OpenSSL versions 3.5 and later.

3rd-Party Vendor Builds

Some Vendors choose to patch/modify/build their own FIPS provider, test it with a Security Laboratory and submit it under their own CMVP certificate, instead of using OpenSSL Project submissions. When doing so, FIPS provider should uniquely identify its own name and version number. The build infrastructure allows to customize FIPS provider build information via changes to strings in VERSION.dat.

Setting "PRE_RELEASE_TAG" (dashed suffix), "BUILD_METADATA" (plus suffix), and "FIPS_VENDOR" allow to control reported FIPS provider name and build version as required for CMVP submission.