wolfSSL FIPS Ready

Do you have a project that will need a FIPS approved cryptographic library at a later date, but want to be ready for it now? wolfSSL FIPS Ready includes the cryptography layer from the public wolfSSL source tree, along with the FIPS tooling enabled for a FIPS Ready build. FIPS Ready allows application developers to assure that they have correctly integrated the necessary FIPS setup, and are correctly using the API and underlying protocols, providing for a seamless transition to the full FIPS certified wolfSSL library for an application. When the time comes, we will shepherd your operating environment through testing and add it to the wolfCrypt FIPS 140-3 certificate. In special situations, a new FIPS 140-3 certificate will be required, but we are ready to provide guidance through the testing and certification process. In both scenarios, FIPS Ready assures that your application will be fully functional with wolfCrypt as certified.

FIPS Ready is open source and dual-licensed. wolfSSL Inc distributes FIPS Ready wolfSSL with the GPLv3 license or can negotiate commercial licensing terms with support if needed beyond the proof of concept phase.

FIPS is a complicated topic. If you have questions after reviewing this document, then just contact us at facts -at- wolfssl dot calm. The email address is obfuscated for the spiders, but the calm is for the calm you’ll feel when you are FIPS Ready.

What is Different from a non-FIPS build of wolfSSL?

The wolfCrypt FIPS API provides wrappers for all the approved algorithm functions that are within the FIPS boundary. The FIPS wrappers can be called directly, or you can keep calling the original APIs; at compile time the API is swapped by the headers so that the FIPS wrappers will be called either way. The FIPS wrapper functions check the status of the internal self-testing before calling the actual function. If the CAST for that specific algorithm has not been run at least one time previously it will run the first time the algorithm is used. Users now have the option to either pre-emptively test algorithms at start up if they wish to avoid the test running at a later time or they can just let the test run when the algorithm is used.

The wolfCrypt FIPS 140-3 ready code has a required power-on self-test (POST) that automatically checks the integrity of the executable in memory, this has not changed since 140-2, only the known answer tests (KATs) for algorithms not used by the POST are now conditional upon use. The executable is organized so the code in the FIPS boundary is contiguous in memory. When the application using the FIPS code starts up, or the shared library is loaded, the default entry point of the library is called, and the POST runs automatically. It has two major parts: the in-core memory check and the known answer tests (KAT) for the algo used by the POST (HMAC-SHA256).

The POST for HMAC-SHA256 is performed first followed by the in-core memory test. The code in memory is hashed with HMAC-SHA256. If the hash matches, the test progresses. Otherwise the FIPS module is placed in an error state and all calls into the module will fail. In this case, the FIPS source code must be updated with the correct integrity hash, and only after recompilation can the module successfully initialize.

All other algorithms in the FIPS boundary are tested with canned data the first time they are used or optionally whenever the developer wants them to run. The output is compared to pre-computed known answers. The test values are all inside the boundary and are checked at the time they are called. Several of the tests have a random component, for example a sign and verify, so a known piece of data is signed and then verified with a canned key. The key generation is tested in a similar fashion.

The FIPS boundary provides confirmation about multiple aspects of your application. The processing of private key access that will assure proper unlocking and relocking of keys according to the FIPS specification. The assurance that no FIPS-forbidden modes or key sizes are being used, along with proper entropy source setup. FIPS Ready also helps discover conflicts with outside sub-system integration your application needs, for example determining if other applications or devices on a network support your new FIPS Ready cipher suites for communication between each other.