PKCS#11 stuff: "sign-only" vs "crypto-accelerator"

[Johan Ihren]

Hi Evan,

On 10 Feb 2010, at 19:09, Evan Hunt wrote:

>> But if I build openssl in "crypto-accelerator" mode I stumble on
>> dnssec-keyfromlabel:
>> 
>> mango:/tmp#pkcs11-list 
>> Enter Pin: 
>> mango:/tmp#pkcs11-keygen -b 2048 -l johani.se-ksk
>> Enter Pin: 
>> mango:/tmp#pkcs11-keygen -b 1024 -l johani.se-zsk
>> Enter Pin: 
>> mango:/tmp#pkcs11-list 
>> Enter Pin: 
>> object[0]: handle 4 class 2 label[13] 'johani.se-zsk' id[0] 
>> object[1]: handle 3 class 3 label[13] 'johani.se-zsk' id[0] 
>> object[2]: handle 2 class 2 label[13] 'johani.se-ksk' id[0] 
>> object[3]: handle 1 class 3 label[13] 'johani.se-ksk' id[0] 
>> mango:/tmp#dnssec-keyfromlabel -l johani.se-ksk -f KSK johani.se
>> dnssec-keyfromlabel: fatal: failed to get key johani.se/RSASHA1: not found
> 
> What kind of HSM are you using?

Here I was using softhsm.

> As a shot in the dark, I would try specifying the engine on the
> dnssec-keyfromlabel command line--"pkcs11:johani.se-ksk".  (That
> shouldn't be necessary, but if it was using the wrong engine for
> some reason then "not found" is the error I'd expect to get.)

Didn't help. And there is only one engine, so there really isn't much chance of using the wrong one.

>> 2. In "sign-only" mode the contents of the K*.key and K*.private is different. Now I don't understand the format of the .private file, but I am curious as to what data is in there as it surely cannot be the private key and it doesn't seem to be the public key. Is it the public key in another format?
> 
> In HSM keys, the private file doesn't store the private key data; it stores
> the information needed to find the key in the HSM--those are the lines
> labeled "Engine:" and "Label:".  It also stores the modulus and public key
> exponent, and the key lifecycle metadata.

Ok.

>> I understand the first paragraph. I think I understand the second
>> paragraph. What I don't understand is what OTHER operations there are in
>> a DNSSEC zone generation context than "key generation" and "zone
>> signing". I.e. more precisely, what is the difference between the two
>> modes?
> 
> In crypto-accelerator mode, it's assumed that the hardware device is faster
> than your CPU at carrying out all cryptographic operations--signing,
> validating against private or public keys, encrypting with private or
> public keys, decrypting with private or public keys, hashing, generating
> random numbers... everything CPU-intensive gets offloaded onto the HSM.
> 
> In sign-only mode it's assumed that your CPU is going to be better at
> computational tasks, so any operation that doesn't require access to the
> private key (encrypting/decrypting/validating with public key, hashing)
> will be done there.

I understand all this. The question I'm asking is "In a DNSSEC ZONE GENERATION CONTEXT, what other operations than key generation and zone signing are there?". And if there is nothing else, then what is the *practical* difference between "crypto accelerator" and "sign only" when I'm only interested in zone generation?

>> dnssec-keyfromlabel: warning: dns_dnssec_findmatchingkeys: error reading key file Kjohani.se.+005+21432.private: not found
>> Kjohani.se.+005+28461
>> mem.c:1093: INSIST(ctx->stats[i].gets == 0U) failed, back trace
> 
> This kind of INSIST means there was a memory leak.  The program ran
> the way it was supposed to, but we forgot to free some memory before
> exiting, and hadn't noticed because we never hit that particular error
> case in our testing, I suppose.  It's annoying, but functionally
> harmless; bug report it and we'll fix it in the next release.

Ok. Thanks.

Regards,

Johan