Create a deterministic RSA key with OpenTEE

[aminusamine]

Hello,

I also working on openTEE and i saw in the GPD internal API that GenerateKey function generates random keys, is there a way to generate deterministic keys according to a parameter transmitted ?

I saw that The TEE_Attribute* argument is indeed used as a public exponent but i'm not sure. Can you please help me on this,

Thank you,
Best regards

[brianmcgillion]

Hi,

Unfortunately GP does not provide a mechanism to create deterministic keys, only random ones.

Br,
Brian

[aminusamine]

Thanks,

I found this header in the tee_storage_api :

static TEE_Result gen_rsa_keypair(TEE_ObjectHandle obj, uint32_t key_size, TEE_Attribute *params,
uint32_t paramCount)
in this function we can found
int pub_exp_index_at_params =
get_attr_index_from_attrArr(TEE_ATTR_RSA_PUBLIC_EXPONENT, params, paramCount);

Do you think that if we create a TEE_Attribute with the public exponent, the process will be deterministic ?

BR,

[brianmcgillion]

No, I do not believe so.

The public exponent is generally one of either - [3, 5, 17, 257, 65537] with 65537 the most commonly used.

[aminusamine]

Thank you for your answer,

Do you think it is possible to add this feature ? and if the answer is yes, where the modification should be done ?

Thanks again,
BR

[cezane]

I think this can be closed...