[PATCH 0/5] net: lwip: root certificates

[Jerome Forissier]

On 2/27/25 17:27, Simon Glass wrote:
> Hi Jerome,
> 
> On Thu, 27 Feb 2025 at 09:09, Jerome Forissier
> <jerome.forissier at linaro.org> wrote:
>>
>> This series adds support for HTTP server authentication using root (CA)
>> certificates.
>>
>> As a first step, the wget command is extended to support a sub-command:
>> cacert <addr> <size>. The memory region shall contain the CA
>> certificates. With this, it is possible to load the certificates from
>> storage or get them from the network for example, which is convenient
>> for testing at least. The Kconfig symbol for this feature is
>> WGET_CACERT=y.
>>
>> Then new Kconfig symbols are added to support providing the certificates
>> at build time, as a DER or PEM encoded X509 collection:
>> WGET_BUILTIN_CACERT=y and WGET_BUILTIN_CACERT_PATH=<some path>.
>> Note that PEM support requires MBEDTLS_LIB_X509_PEM=y (for the cacert
>> command as well as for the builtin way).
>>
>> Here is a complete example (showing only the relevant output from the
>> various commands):
>>
>>  make qemu_arm64_lwip_defconfig
>>  wget https://curl.se/ca/cacert.pem
>>  echo CONFIG_WGET_BUILTIN_CACERT=y >>.config
>>  echo CONFIG_WGET_BUILTIN_CACERT_PATH=cacert.pem >>.config
>>  make olddefconfig
>>  make -j$(nproc) CROSS_COMPILE="ccache aarch64-linux-gnu-"
>>  qemu-system-aarch64 -M virt -nographic -cpu max \
>>         -object rng-random,id=rng0,filename=/dev/urandom \
>>         -device virtio-rng-pci,rng=rng0 -bios u-boot.bin
>>  => dhcp
>>  # HTTPS transfer using the builtin CA certificates
>>  => wget https://www.google.com/
>>  18724 bytes transferred in 15 ms (1.2 MiB/s)
>>  # Disable certificate validation
>>  => wget cacert 0 0
>>  # Unsafe HTTPS transfer
>>  => wget https://www.google.com/
>>  WARNING: no CA certificates, HTTPS connections not authenticated
>>  16570 bytes transferred in 15 ms (1.1 MiB/s)
>>  # Dowload and apply CA certificates from the net
>>  => wget https://curl.se/ca/cacert.pem
>>  WARNING: no CA certificates, HTTPS connections not authenticated
>>  ##
>>  233263 bytes transferred in 61 ms (3.6 MiB/s)
>>  => wget cacert $fileaddr $filesize
>>  # Now HTTPS is authenticated against the new CA
>>  => wget https://www.google.com/
>>  18743 bytes transferred in 14 ms (1.3 MiB/s)
>>  # Drop the certificates again...
>>  => wget cacert 0 0
>>  # Check that transfer is not secure
>>  => wget https://www.google.com/
>>  WARNING: no CA certificates, HTTPS connections not authenticated
>>  # Restore the builtin CA
>>  => wget cacert builtin
>>  # No more WARNING
>>  => wget https://www.google.com/
>>  18738 bytes transferred in 15 ms (1.2 MiB/s)
>>
>> Jerome Forissier (5):
>>   net: lwip: extend wget to support CA (root) certificates
>>   lwip: tls: enforce checking of server certificates based on CA
>>     availability
>>   lwip: tls: warn when no CA exists amd log certificate validation
>>     errors
>>   net: lwip: add support for built-in root certificates
>>   configs: qemu_arm64_lwip_defconfig: enable WGET_CACERT and
>>     MBEDTLS_LIB_X509_PEM
>>
>>  cmd/Kconfig                                   | 29 ++++++
>>  cmd/net-lwip.c                                | 19 +++-
>>  configs/qemu_arm64_lwip_defconfig             |  2 +
>>  .../src/apps/altcp_tls/altcp_tls_mbedtls.c    |  9 +-
>>  .../lwip/apps/altcp_tls_mbedtls_opts.h        |  6 --
>>  lib/mbedtls/Makefile                          |  3 +
>>  lib/mbedtls/mbedtls_def_config.h              |  5 ++
>>  net/lwip/Makefile                             |  6 ++
>>  net/lwip/wget.c                               | 90 ++++++++++++++++++-
>>  9 files changed, 158 insertions(+), 11 deletions(-)
> 
> Did you manage to add some sandbox tests for lwip?

Unfortunately not. I am testing mostly with QEMU (qemu_arm64_lwip_defconfig)
and sometimes with KV260 and i.MX93.

Regards,
-- 
Jerome