tcrypt failing on hmac(crc32)

tcrypt failing on hmac(crc32)

[Marcus Meissner]

Hi,

when enabling the testmgr framework and FIPS in 4.6 and 4.4 and running "modprobe tcrypt"

[ 1153.298266] alg: hash: Failed to load transform for hmac(crc32): -2
[ 1153.340636] tcrypt: one or more tests failed!

I spent some hours making sense of what is missing, but I got lost in the maze
of the crypto apis between sync and async hashes somewhere.

Does anyone know the solution for this, otherwise I will need to continue looking.

Ciao, Marcus

Re: tcrypt failing on hmac(crc32)

[Stephan Mueller]

Am Mittwoch, 25. Mai 2016, 09:07:52 schrieb Marcus Meissner:

Hi Marcus,

> Hi,
> 
> when enabling the testmgr framework and FIPS in 4.6 and 4.4 and running
> "modprobe tcrypt"

        }, {
                .alg = "hmac(crc32)",
                .test = alg_test_hash,
...

fips_allowed = 1 missing?
> 
> [ 1153.298266] alg: hash: Failed to load transform for hmac(crc32): -2
> [ 1153.340636] tcrypt: one or more tests failed!
> 
> I spent some hours making sense of what is missing, but I got lost in the
> maze of the crypto apis between sync and async hashes somewhere.
> 
> Does anyone know the solution for this, otherwise I will need to continue
> looking.
> 
> Ciao, Marcus
> --
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Ciao
Stephan

Re: tcrypt failing on hmac(crc32)

[Marcus Meissner]

Hi,

On Wed, May 25, 2016 at 09:10:31AM +0200, Stephan Mueller wrote:
> Am Mittwoch, 25. Mai 2016, 09:07:52 schrieb Marcus Meissner:
> 
> Hi Marcus,
> 
> > Hi,
> > 
> > when enabling the testmgr framework and FIPS in 4.6 and 4.4 and running
> > "modprobe tcrypt"
> 
>         }, {
>                 .alg = "hmac(crc32)",
>                 .test = alg_test_hash,
> ...
> 
> fips_allowed = 1 missing?

The kernel was not in FIPS mode, and adding it did not help. :/

Ciao, Marcus

Re: tcrypt failing on hmac(crc32)

[Stephan Mueller]

Am Mittwoch, 25. Mai 2016, 13:36:10 schrieb Marcus Meissner:

Hi Marcus,

> Hi,
> 
> On Wed, May 25, 2016 at 09:10:31AM +0200, Stephan Mueller wrote:
> > Am Mittwoch, 25. Mai 2016, 09:07:52 schrieb Marcus Meissner:
> > 
> > Hi Marcus,
> > 
> > > Hi,
> > > 
> > > when enabling the testmgr framework and FIPS in 4.6 and 4.4 and running
> > > "modprobe tcrypt"
> > > 
> >         }, {
> >         
> >                 .alg = "hmac(crc32)",
> >                 .test = alg_test_hash,
> > 
> > ...
> > 
> > fips_allowed = 1 missing?
> 
> The kernel was not in FIPS mode, and adding it did not help. :/

Sorry, I read FIPS and implied fips=1 :-)

Ciao
Stephan

Re: tcrypt failing on hmac(crc32)

[Marcus Meissner]

On Wed, May 25, 2016 at 01:39:46PM +0200, Stephan Mueller wrote:
> Am Mittwoch, 25. Mai 2016, 13:36:10 schrieb Marcus Meissner:
> 
> Hi Marcus,
> 
> > Hi,
> > 
> > On Wed, May 25, 2016 at 09:10:31AM +0200, Stephan Mueller wrote:
> > > Am Mittwoch, 25. Mai 2016, 09:07:52 schrieb Marcus Meissner:
> > > 
> > > Hi Marcus,
> > > 
> > > > Hi,
> > > > 
> > > > when enabling the testmgr framework and FIPS in 4.6 and 4.4 and running
> > > > "modprobe tcrypt"
> > > > 
> > >         }, {
> > >         
> > >                 .alg = "hmac(crc32)",
> > >                 .test = alg_test_hash,
> > > 
> > > ...
> > > 
> > > fips_allowed = 1 missing?
> > 
> > The kernel was not in FIPS mode, and adding it did not help. :/
> 
> Sorry, I read FIPS and implied fips=1 :-)

I think we are running in a precondition

        ds = salg->digestsize;		// is CHKSUM_DIGEST_SIZE == 4 for CRC32
        ss = salg->statesize;		// ? cant find it
        alg = &salg->base; 		// base.cra_blocksize seems CHKSUM_BLOCKSIZE == 1
        if (ds > alg->cra_blocksize ||
            ss < alg->cra_blocksize)
                goto out_put_alg;

	4 > 1 ... so EINVAL return.

If this is the case, hmac(crc32) might be kind of non-sensical?

Ciao, Marcus

Re: tcrypt failing on hmac(crc32)

[Marcus Meissner]

On Wed, May 25, 2016 at 03:05:28PM +0200, Marcus Meissner wrote:
> On Wed, May 25, 2016 at 01:39:46PM +0200, Stephan Mueller wrote:
> > Am Mittwoch, 25. Mai 2016, 13:36:10 schrieb Marcus Meissner:
> > 
> > Hi Marcus,
> > 
> > > Hi,
> > > 
> > > On Wed, May 25, 2016 at 09:10:31AM +0200, Stephan Mueller wrote:
> > > > Am Mittwoch, 25. Mai 2016, 09:07:52 schrieb Marcus Meissner:
> > > > 
> > > > Hi Marcus,
> > > > 
> > > > > Hi,
> > > > > 
> > > > > when enabling the testmgr framework and FIPS in 4.6 and 4.4 and running
> > > > > "modprobe tcrypt"
> > > > > 
> > > >         }, {
> > > >         
> > > >                 .alg = "hmac(crc32)",
> > > >                 .test = alg_test_hash,
> > > > 
> > > > ...
> > > > 
> > > > fips_allowed = 1 missing?
> > > 
> > > The kernel was not in FIPS mode, and adding it did not help. :/
> > 
> > Sorry, I read FIPS and implied fips=1 :-)
> 
> I think we are running in a precondition
> 
>         ds = salg->digestsize;		// is CHKSUM_DIGEST_SIZE == 4 for CRC32
>         ss = salg->statesize;		// ? cant find it
>         alg = &salg->base; 		// base.cra_blocksize seems CHKSUM_BLOCKSIZE == 1
>         if (ds > alg->cra_blocksize ||
>             ss < alg->cra_blocksize)
>                 goto out_put_alg;
> 
> 	4 > 1 ... so EINVAL return.
> 
> If this is the case, hmac(crc32) might be kind of non-sensical?

And it actually is:

[  180.942532] hmac: blocksize check failed, ds=4, cra_blocksize=1, ss=4
[  180.942541] alg: hash: Failed to load transform for hmac(crc32): -2
[  180.989191] tcrypt: one or more tests failed!

Should I remove hmac(crc32) from the testmgr list?

Ciao, Marcus

Re: tcrypt failing on hmac(crc32)

[Stephan Mueller]

Am Freitag, 27. Mai 2016, 11:19:32 schrieb Marcus Meissner:

Hi Marcus,

> 
> And it actually is:
> 
> [  180.942532] hmac: blocksize check failed, ds=4, cra_blocksize=1, ss=4
> [  180.942541] alg: hash: Failed to load transform for hmac(crc32): -2
> [  180.989191] tcrypt: one or more tests failed!
> 
> Should I remove hmac(crc32) from the testmgr list?

I am wondering about that: there are test vectors for this cipher, so there 
seem to be valid use cases. But the implementation is broken and nobody 
noticed up to now. So, it seems it is not in use?

Given that, I would think that hmac(crc32) could be removed from testmgr.

Ciao
Stephan