[EXTERNAL] MD5 and FIPS

[Hubert Kario]

On Thursday, 2 February 2023 16:31:20 CET, Matthew Heimlich wrote:
> The question of whether or not non-FIPS-compliant algorithms 
> should be allowed for non-cryptographic use is moot if you're 
> deploying to environments requiring FIPS validation where the 
> FIPS requirement is configured at the system level. A full audit 
> of every line of code of every application present on the 
> system(s) is completely infeasible. There is no reasonable way 
> to ensure that people are using insecure algorithms "the right 
> way" in cases where security is a primary concern. A blanket ban 
> is the much more palatable option. And I can't think of a single 
> case where one couldn't just as easily hash files using a 
> compliant algorithm outside of support of legacy systems, in 
> which case you'd have to go through the POAM/waiver process 
> anyway. You'll have a hard time convincing anyone that an 
> application under active development will undergo enough 
> inconvenience by switching to a compliant hashing algorithm that 
> they'd waiver you these days.

What's compliant and what's not is between you and your auditor.

I'm just mentioning the technical means how to use those algorithms
with some older FIPS certified modules without getting the whole system out
of FIPS mode.

> On Thu, Feb 2, 2023 at 7:00 AM Hubert Kario <hkario at redhat.com> wrote:
> On Thursday, 2 February 2023 01:45:00 CET, Sands, Daniel via openssl-users 
> wrote:
>>
>>> -----Original Message-----
>>> From: openssl-users <openssl-users-bounces at openssl.org> On Behalf Of Dr
>>> Paul Dale
>>> Sent: Wednesday, February 1, 2023 2:33 PM
>>> To: openssl-users at openssl.org
>>> Subject: [EXTERNAL] Re: MD5 and FIPS
>>> 
>>> If you are using OpenSSL 1.0.2 and the old FOM, you're out of luck.
>>> 
>>> If you are using OpenSSL 3.0 with the FIPS provider, you can 
>>> still access MD5 by
>>> loading appropriate providers and specifying a property query.  See the
>>> migration or FIPS guides.
>>
>> This sounds like an acceptable workaround.  So if I load the 
>> legacy provider, then request MD5 (or SHA1) explicitly through 
>> that provider, it should provide a working context?
>
> For some old FIPS modules you can also re-enable the md5 hash by using
> EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
>
> Looking how Python handles the usedforsecurity keyword argument in hashlib
> module is a usually a good idea.

-- 
Regards,
Hubert Kario
Principal Quality Engineer, RHEL Crypto team
Web: www.cz.redhat.com
Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic