On 7/25/2018 10:47 AM, Viktor Dukhovni wrote:


On Jul 25, 2018, at 10:05 AM, Ken Goldman <kgold...@us.ibm.com> wrote:

I have a certificate with a non-standard public key algorithm -rsaesOaep.  See 
snippet #2.

With openssl 1.0, I can validate  the certificate chain.  With openssl 1.1 it 
fails with the error X509_V_ERR_EE_KEY_TOO_SMALL.  See dump #1.

I believe that this is due to new 1.1 code x509_vfy.c:check_key_level() calling 
X509_get0_pubkey().  That call will fail for the non-standard algorithm.

The certificate is for old vendor hardware that cannot be updated.  What are my 
choices?

- Remain on 1.0
- Some configuration option?
- Something else?

The immediate cause is the order of the checks in check_key_level().
It first checks for a supported key, and only then short-circuits
the logic at level <= 0 (my fault).  Perhaps level 0 should not be
strict in this way, in which case we might reverse the order of
then (pkey == NULL) and (level <= 0) tests:

static int check_key_level(X509_STORE_CTX *ctx, X509 *cert)
{
     EVP_PKEY *pkey = X509_get0_pubkey(cert);
     int level = ctx->param->auth_level;

     /* Unsupported or malformed keys are not secure */
     if (pkey == NULL)
         return 0;

     if (level <= 0)
         return 1;
     if (level > NUM_AUTH_LEVELS)
         level = NUM_AUTH_LEVELS;

     return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1];
}

If you're suggesting that altering the above code to do the level check before the call to get pkey, I think that would fix my problem.

... if I can set level to a negative value. How do I set level? Is there an API or a configuration file.


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