[openssl-dev] Access to ECDSA_METHOD do_verify function from engine

[Douglas E Engert]

On 7/21/2017 7:19 AM, Johannes Bauer wrote:
> On 21.07.2017 14:00, Douglas E Engert wrote:
> 
>> It uses either:
>>      ops = ECDSA_METHOD_new((ECDSA_METHOD *)ECDSA_OpenSSL());
>> or
>>      ops = EC_KEY_METHOD_new((EC_KEY_METHOD *)EC_KEY_OpenSSL());
>>
>> which copy the default structure to the new opaque structure.
>> It then sets the routines it wants to change.
> 
> Ah, I missed this. Works perfectly, thank you very much for the tip.
> 
> I've also ported the engine to work on both OpenSSL 1.0 and 1.1 --
> however the cast to a (mutable) EC_KEY_METHOD* isn't necessary for 1.1
> (where the prototype accepts a const EC_KEY_METHOD*).
> 
> However, when I want to set the sign function for v1.1, I want to
> override sig_sign, but use the OpenSSL default sign and sign_setup
> functions. For this, I use EC_KEY_METHOD_get_sign. Unfortunately, for no
> obvious reason, EC_KEY_METHOD_get_sign requires a EC_KEY_METHOD* instead
> of a const EC_KEY_METHOD*. Do you happen to know why this is? Looking at
> the code, there doesn't seem to be a reason for it. Gives an ugly
> compile-time warning.

I don't see your problem with OpenSSL-1.1.0f. I don't recall seeing it with
earlier version either. p11_ec.c does:


647         static EC_KEY_METHOD *ops = NULL;
648         int (*orig_sign)(int, const unsigned char *, int, unsigned char *,
649                 unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) = NULL;

653                 ops = EC_KEY_METHOD_new((EC_KEY_METHOD *)EC_KEY_OpenSSL());
654                 EC_KEY_METHOD_get_sign(ops, &orig_sign, NULL, NULL);
655                 EC_KEY_METHOD_set_sign(ops, orig_sign, NULL, pkcs11_ecdsa_sign_sig);



> 
> Cheers,
> Johannes
> 

-- 

  Douglas E. Engert  <DEEngert at gmail.com>