On 08/13/2015 07:23 AM, David Howells wrote:
> Tadeusz Struk <tadeusz.struk@xxxxxxxxx> wrote:
>
>> const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
>> - [PKEY_ALGO_DSA] = "DSA",
>> - [PKEY_ALGO_RSA] = "RSA",
>> + [PKEY_ALGO_DSA] = "dsa",
>> + [PKEY_ALGO_RSA] = "rsa",
>> };
>
> Be aware that these are exposed to userspace through /proc. The change
> probably doesn't matter, but you might need to update the documentation.
>
>> +int public_key_verify_signature(const struct public_key *pkey,
>> const struct public_key_signature *sig)
>> {
>> ...
>> - return algo->verify_signature(pk, sig);
>> + return rsa_pkcs1_v1_5_verify_signature(pkey, sig);
>> }
>
> No. You can't assume RSA here. It's quite likely we'll have to support ECDSA
> or similar soon. This must be contingent on the algorithm selected.
>
>> {
>> const struct public_key *pk = key->payload.data;
>> +
>> return public_key_verify_signature(pk, sig);
>> }
>
> That's nothing to do with this patch.
>
>> +static int rsa_signture_verify(const u8 *H, const u8 *EM, size_t k,
>
> 'signture' -> 'signature'.
>
>> +/*
>> + * Perform the RSA signature verification.
>> + * @H: Value of hash of data and metadata
>> + * @EM: The computed signature value
>> + * @k: The size of EM (EM[0] is an invalid location but should hold 0x00)
>> + * @hash_size: The size of H
>> + * @asn1_template: The DigestInfo ASN.1 template
>> + * @asn1_size: Size of asm1_template[]
>> + */
>> +static int rsa_signture_verify(const u8 *H, const u8 *EM, size_t k,
>> + size_t hash_size, const u8 *asn1_template,
>> + size_t asn1_size)
>> +{
>
> Why is this here and not in crypto/rsa.c?
>
>> + /* initlialzie out buf */
>
> 'initialise'.
>
>> - /* Decode the public key */
>> - ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
>> - ctx->key, ctx->key_size);
>> - if (ret < 0)
>> + cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
>> + if (!cert->pub->key)
>> goto error_decode;
>
> The generic public key code should *not* see the container wrappings (ASN.1
> from an X.509 cert in this case). The public key could be supplied by OpenPGP
> instead, for example, or directly by a driver.
>
> Further, at this point, we need to make sure that the data we were given has
> the right bits and emit EBADMSG if it doesn't.
>
> Okay, I can accept that the public_key struct might just have a list of void *
> and size_t fields that get filled in, one for each integer that we extract
> rather than MPIs, but we should not expose the generic code to the stuff we've
> parsed away.
>
>> struct public_key {
>> - const struct public_key_algorithm *algo;
>> - u8 capabilities;
>> -#define PKEY_CAN_ENCRYPT 0x01
>> -#define PKEY_CAN_DECRYPT 0x02
>> -#define PKEY_CAN_SIGN 0x04
>> -#define PKEY_CAN_VERIFY 0x08
>
> You still need the capabilities. The X.509 certificate and the OpenPGP
> message indicate restrictions on the key that we need to honour.
Thanks David for all your feedback. I'll rework it according to your comments.
Regards,
T
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
