Re: ENGINE_load_private_key does not get invoked

[Dmitry Belyavsky <beldmit@xxxxxxxxx>]

Dear Mahendra,

On Mon, Apr 20, 2020 at 7:27 PM Mahendra SP <mahendra.sp@xxxxxxxxx> wrote:

Hi Dmitry Belyavsky,

Thank you for the inputs. If I understand correctly, the reference indicates loading the private key to engine instance.

My requirement is to call the ENGINE_set_load_privkey_function so that the callback gets called before each RSA private key operation.

Reason being, application can use either key with TPM or keys in software. So I need to load the correct key before each operation gets invoked.I was looking at 

ENGINE_set_load_privkey_function  to set the callback.Is this understanding correct ? 

You specify the engine-specific function via ENGINE_set_load_privkey_function.

After that, you can load your key using ENGINE_load_private_key - 

if you pass the reference to your engine to it, the function set via 

ENGINE_set_load_privkey_function will be used.

Please suggest.

Thanks

Mahendra

  

On Mon, Apr 20, 2020 at 8:43 PM Dmitry Belyavsky <beldmit@xxxxxxxxx> wrote:

Dear Mahendra,

Take a look at the load_key function in the apps/apps.c as a referent example.

On Mon, Apr 20, 2020 at 2:34 PM Mahendra SP <mahendra.sp@xxxxxxxxx> wrote:

Hi All,

While writing the engine implementation for private key encryption and decryption, I need to get the private key from external source. 

ENGINE_set_load_privkey_function(e, load_tpm_private_key)

Above API is success.

RSA structure is as below.

RSA_METHOD my_rsa_struct =
{
   "MY RSA method",
   NULL,
   NULL,
   MyRSAPrivEnc,
   MyRSAPrivDec,
   NULL, 
   NULL,
   NULL, 
   NULL,
   0, 
   NULL,
   NULL,
   NULL,
   NULL
};

However, the routine load_tpm_private_key  does not get invoked during private key encryption and decryption.

Private key encryption and decryption gets routed to the above overloaded routines namely " MyRSAPrivEnc " and " MyRSAPrivDec". But  load_tpm_private_key never gets invoked. 

Is there a flag  to force the same ? I have tried it using openssl 1.0.2 version. All other engine calls work as expected, but not this one. 

I have also tried to debug in ENGINE_load_private_key in eng_pkey.c file. I dont see this function getting invoked. In this function, the private key callback set above gets invoked.

 

Please suggest if I am missing something here.

Thanks

Mahendra

--

SY, Dmitry Belyavsky

--

SY, Dmitry Belyavsky