Causes performance drop in initialization so needs to be opt-in.
Distributors are capable of opt-in enabling this. Could be also handled by
kernel-command line in the future.
Reported-by: Vitor Soares <[email protected]>
Closes: https://lore.kernel.org/linux-integrity/[email protected]/#t
Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation")
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
drivers/char/tpm/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index e63a6a17793c..db41301e63f2 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -29,7 +29,7 @@ if TCG_TPM
config TCG_TPM2_HMAC
bool "Use HMAC and encrypted transactions on the TPM bus"
- default y
+ default n
select CRYPTO_ECDH
select CRYPTO_LIB_AESCFB
select CRYPTO_LIB_SHA256
--
2.45.0
On Sat, 2024-05-18 at 14:34 +0300, Jarkko Sakkinen wrote:
> Causes performance drop in initialization so needs to be opt-in.
> Distributors are capable of opt-in enabling this. Could be also
> handled by kernel-command line in the future.
>
> Reported-by: Vitor Soares <[email protected]>
> Closes:
> https://lore.kernel.org/linux-integrity/[email protected]/#t
Hey, there's no response on that thread verifying the primary
generation is the culprit. Could we at least wait for a reply before
taking such drastic action based on surmise?
I'd be really surprised if it is primary generation. If I used an RSA
primary it would be a problem (My oldest TPM takes a couple of minutes
to generate one) but the longest I've seen an EC primary take to
generate is still less than a second.
James
On Mon May 20, 2024 at 5:50 PM EEST, James Bottomley wrote:
> On Sat, 2024-05-18 at 14:34 +0300, Jarkko Sakkinen wrote:
> > Causes performance drop in initialization so needs to be opt-in.
> > Distributors are capable of opt-in enabling this. Could be also
> > handled by kernel-command line in the future.
> >
> > Reported-by: Vitor Soares <[email protected]>
> > Closes:
> > https://lore.kernel.org/linux-integrity/[email protected]/#t
>
> Hey, there's no response on that thread verifying the primary
> generation is the culprit. Could we at least wait for a reply before
> taking such drastic action based on surmise?
>
> I'd be really surprised if it is primary generation. If I used an RSA
> primary it would be a problem (My oldest TPM takes a couple of minutes
> to generate one) but the longest I've seen an EC primary take to
> generate is still less than a second.
>
> James
Nothing is going to happen before rc1 is out, it would be earliest rc2.
ECDSA should be always faster than RSA so you're right that it does not
necessarily make much sense, unless there are TPM2 chips with only RSA.
It might make sense to have at least a command-line option to disable
hmac.
BR, Jarkko