On Wed, May 29, 2024 at 03:42:04PM -0400, Raymond Mao wrote:
Hi Tom,
On Wed, 29 May 2024 at 14:43, Tom Rini trini@konsulko.com wrote:
On Wed, May 29, 2024 at 02:38:10PM -0400, Raymond Mao wrote:
Hi Tom,
On Wed, 29 May 2024 at 14:01, Tom Rini trini@konsulko.com wrote:
On Wed, May 29, 2024 at 01:42:16PM -0400, Raymond Mao wrote:
Hi Tom,
On Wed, 29 May 2024 at 12:58, Tom Rini trini@konsulko.com wrote:
On Tue, May 28, 2024 at 07:09:14AM -0700, Raymond Mao wrote:
> Port mbedtls with dummy libc header files. > Add mbedtls default config header file. > Optimize mbedtls default config by disabling unused features to > reduce the target size. > Add mbedtls kbuild makefile. > Add Kconfig and mbedtls config submenu. [snip] > diff --git a/lib/mbedtls/Kconfig b/lib/mbedtls/Kconfig > new file mode 100644 > index 00000000000..d6e77d56871 > --- /dev/null > +++ b/lib/mbedtls/Kconfig > @@ -0,0 +1,25 @@ > +menuconfig MBEDTLS_LIB > + bool "Use mbedtls libraries" > + select MBEDTLS_LIB_CRYPTO > + select MBEDTLS_LIB_X509 > + help > + Enable mbedtls libraries > + > +if MBEDTLS_LIB > + > +config MBEDTLS_LIB_CRYPTO > + bool "Crypto library" > + help > + Enable mbedtls crypto library > + > +config MBEDTLS_LIB_X509 > + bool "X509 library" > + help > + Enable mbedtls X509 library > + > +config MBEDTLS_LIB_TLS > + bool "TLS library" > + help > + Enable mbedtls TLS library > + > +endif # MBEDTLS_LIB
We need much more granularity here, and to re-think some existing symbols too perhaps. What we should be able to do is pick mbedTLS
or
"legacy SW implementation" or "HW implementation" for the various algorithms, and that in turn can have some higher level grouping
to it.
This should then negate a bunch of the Makefile work you're doing
as we
won't have CONFIG_SHA256 enabled as we'll have
CONFIG_MBEDTLS_LIB_SHA256
or whatever enabled.
I think we should use CONFIG_MBEDTLS_LIB_[CRYPTO,X509,TLS] for
high-level
grouping. Underneath, the CONFIG_SHA[1,256,512] switches (and other crypto
options)
can be used as sub build options in both MbedTLS and "legacy libs".
Take hash as an example, if the users prefer to use MbedTLS other
than
"legacy libs" for hash operation, CONFIG_MBEDTLS_LIB_CRYPTO should be defined as the
main
switch (the users can still prefer to use "legacy libs" for X509 by keeping CONFIG_MBEDTLS_LIB_X509 disabled). Then enable the algorithms they need (e.g. CONFIG_SHA256) - the
algorithm
options works for both MbedTLS and "legacy libs".
HW implementations with MbedTLS (aka, Alternative algorithms in
MbedTLS)
is
another topic which is not covered in this patch set (It needs to migrate
each
vendor's solution under MbedTLS alternative algorithm). Current patch set is focused on SW implementation with MbedTLS.
The "easy" problem with what's in v3 is that X509 and CRYPTO are select'd under the main heading.
Not sure if I get what you mentioned, currently all MbedTLS options are under Library routines > Security support Do you think we should keep them in other places?
The harder problem is that we intentionally have granularity for SHA256, SHA512, etc, etc and all of that goes away with the current Kconfig option if you select mbedTLS.
We
need to bring that back. And we shouldn't need to have all of the ifneq statements in Makefiles because both CONFIG_SHA256 and CONFIG_MBEDLTS_LIB_CRYPTO_SHA256 will not be true (Or possibly, CONFIG_SHA256 gates things U-Boot's internal API for sha256'ing something and CONFIG_LEGACY_SHA256 controls building lib/sha256.c).
I think we should not introduce new ones like CONFIG_LEGACY_,
CONFIG_SHA[1,256,512] should be used no matter whether MbedTLS is enabled or not. I understand your concern, I will bring CONFIG_SHA[1,256,512] back when MbedTLS is enabled. Those options should control the options in the
MbedTLS
default config file.
My concern is that we do not have the correct level of granularity, and that can partly be seen by the number of ifneq(...) statements being added around already conditional logic. We should have almost none of those, in the end, is what I'm saying. We have a mechanism for configuring the build, Kconfig, and that should drive the decisions as much as possible.
The `ifneq(ONFIG_MBEDTLS_LIB_*)` statements are due to the fact that we still need lib/Makefile and lib/crypto/Makefile when building hash and x509 stuffs with MbedTLS enabled. To address this, I guess we have to first refactor all "legacy libs" that will be replaced by MbedTLS: Move md5, sha* from lib to to a new dir lib/hash and move public_key, rsapubkey*, rsa_helper, x509*, pkcs7*,mscode* from lib/crypto to a new dir lib/x509. When they are all independent modules with separated Makefile, we can remove `ifneq(ONFIG_MBEDTLS_LIB_*)` and all can be driven in lib/Makefile.
Is that something you expect? If yes I can do this for v4, or put it into another prerequisite/refactor series.
We should not need to do that because we should not have CONFIG_SHA256 set if we are not building lib/sha256.c at that stage, is what I'm saying. CONFIG_LEGACY_SHA256 should control it and CONFIG_SHA256 should control the API and CONFIG_MBEDTLS_LIB_CRYPTO_SHA256 should control the mbedTLS version, and this should either expand on, or if needed update/rework, the mechanism that lets us also have say CONFIG_ARMV8_CE_SHA256 for using that HW based version of the support.