Hi Simon, On Thu, 5 Sept 2024 at 20:43, Simon Glass <s...@chromium.org> wrote:
> Hi Raymond, > > On Tue, 3 Sept 2024 at 08:59, Raymond Mao <raymond....@linaro.org> wrote: > > > > Hi Simon, > > > > On Sat, 17 Aug 2024 at 11:58, Simon Glass <s...@chromium.org> wrote: > >> > >> Hi Raymond, > >> > >> On Fri, 16 Aug 2024 at 15:44, Raymond Mao <raymond....@linaro.org> > wrote: > >> > > >> > Integrate MbedTLS v3.6 LTS (currently v3.6.0) with U-Boot. > >> > > >> > Motivations: > >> > ------------ > >> > > >> > 1. MbedTLS is well maintained with LTS versions. > >> > 2. LWIP is integrated with MbedTLS and easily to enable HTTPS. > >> > 3. MbedTLS recently switched license back to GPLv2. > >> > > >> > Prerequisite: > >> > ------------- > >> > > >> > This patch series requires mbedtls git repo to be added as a > >> > subtree to the main U-Boot repo via: > >> > $ git subtree add --prefix lib/mbedtls/external/mbedtls \ > >> > https://github.com/Mbed-TLS/mbedtls.git \ > >> > v3.6.0 --squash > >> > Moreover, due to the Windows-style files from mbedtls git repo, > >> > we need to convert the CRLF endings to LF and do a commit manually: > >> > $ git add --renormalize . > >> > $ git commit > >> > > >> > New Kconfig options: > >> > -------------------- > >> > > >> > `MBEDTLS_LIB` is for MbedTLS general switch. > >> > `MBEDTLS_LIB_CRYPTO` is for replacing original digest and crypto libs > with > >> > MbedTLS. > >> > `MBEDTLS_LIB_X509` is for replacing original X509, PKCS7, MSCode, > ASN1, > >> > and Pubkey parser with MbedTLS. > >> > `LEGACY_CRYPTO` is introduced as a main switch for legacy crypto > library. > >> > `LEGACY_CRYPTO_BASIC` is for the basic crypto functionalities and > >> > `LEGACY_CRYPTO_CERT` is for the certificate related functionalities. > >> > For each of the algorithm, a pair of `<alg>_LEGACY` and > `<alg>_MBEDTLS` > >> > Kconfig options are introduced. Meanwhile, `SPL_` Kconfig options are > >> > introduced. > >> > > >> > In this patch set, MBEDTLS_LIB, MBEDTLS_LIB_CRYPTO and > MBEDTLS_LIB_X509 > >> > are by default enabled in qemu_arm64_defconfig and sandbox_defconfig > >> > for testing purpose. > >> > > >> > Patches for external MbedTLS project: > >> > ------------------------------------- > >> > > >> > Since U-Boot uses Microsoft Authentication Code to verify PE/COFFs > >> > executables which is not supported by MbedTLS at the moment, > >> > addtional patches for MbedTLS are created to adapt with the EFI > loader: > >> > 1. Decoding of Microsoft Authentication Code. > >> > 2. Decoding of PKCS#9 Authenticate Attributes. > >> > 3. Extending MbedTLS PKCS#7 lib to support multiple signer's > certificates. > >> > 4. MbedTLS native test suites for PKCS#7 signer's info. > >> > > >> > All above 4 patches (tagged with `mbedtls/external`) are submitted to > >> > MbedTLS project and being reviewed, eventually they should be part of > >> > MbedTLS LTS release. > >> > But before that, please merge them into U-Boot, otherwise the building > >> > will be broken when MBEDTLS_LIB_X509 is enabled. > >> > > >> > See below PR link for the reference: > >> > https://github.com/Mbed-TLS/mbedtls/pull/9001 > >> > > >> > Miscellaneous: > >> > -------------- > >> > > >> > Optimized MbedTLS library size by tailoring the config file > >> > and disabling all unnecessary features for EFI loader. > >> > From v2, original libs (rsa, asn1_decoder, rsa_helper, md5, sha1, > sha256, > >> > sha512) are completely replaced when MbedTLS is enabled. > >> > From v3, the size-growth is slightly reduced by refactoring Hash > functions. > >> > From v6, smaller implementations for SHA256 and SHA512 are enabled and > >> > target size reduce significantly. > >> > Target(QEMU arm64) size-growth when enabling MbedTLS: > >> > v1: 6.03% > >> > v2: 4.66% > >> > v3 - v5: 4.55% > >> > v6: 2.90% > >> > > >> > Please see the latest output from buildman for size-growth on QEMU > arm64, > >> > Sandbox and Nanopi A64. [1] > >> > > >> > Tests done: > >> > ----------- > >> > > >> > EFI Secure Boot test (EFI variables loading and verifying, EFI signed > image > >> > verifying and booting) via U-Boot console. > >> > EFI Secure Boot and Capsule sandbox test passed. > >> > > >> > Known issues: > >> > ------------- > >> > > >> > None. > >> > >> I wonder if we could leave out the SHA stuff? The algorithms are > >> stable and this would seem to avoid much of the size growth, and all > >> the pain of trying to integrate another yet another hashing layer (we > >> already have normal, progressive and h/w acceleration, plus > >> UCLASS_HASH which h/w acceleration should use but that migration never > >> happened). I struggle to see any benefit in replacing U-Boot's very > >> solid hashing infra with something else, particularly as this series > >> adds yet another. Better to invest the time to refactor it. I asked > >> about this before and was told that it would happen 'later'. Let's > >> just not change it at all, then it is more likely someone will sort it > >> out. > >> > > Unfortunately, MbedTLS depends on its own digest layer. Unless we patch > MbedTLS > > to allow an external digest library from U-Boot ... > > Yes that sounds best. It looks like only a few call sites, so it > should be a matter of leaving out the MbedTLS code and adding some > static inlines. > > Inspired by Ilias's reply to patch #7, though we can use the MbedTLS hash alternative options, we still need to convert all U-Boot hash APIs to adapt to the MbedTLS style. This will impact all callers in U-Boot and I don't think it worth to do, at least now. As the first patch set to introduce MbedTLS to U-Boot with turning on all necessary features, I think this patch set is in the best way with an overall consideration. [snip] Raymond
