[PATCH v4 8/8] test: lib: add test for key derivation

[Philippe REYNES]

Hi Raymond,


Le 13/12/2024 à 18:00, Raymond Mao a écrit :
>
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>
> Hi Philippe,
>
> On Thu, 12 Dec 2024 at 08:37, Philippe Reynes 
> <philippe.reynes at softathome.com> wrote:
>
>     Adds a test for the function sha256_hkdf.
>
>     Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
>     ---
>      test/lib/Makefile           |   1 +
>      test/lib/test_sha256_hkdf.c | 107
>     ++++++++++++++++++++++++++++++++++++
>      2 files changed, 108 insertions(+)
>      create mode 100644 test/lib/test_sha256_hkdf.c
>
>     diff --git a/test/lib/Makefile b/test/lib/Makefile
>     index 4c0abcba81a..24ce6ed8f00 100644
>     --- a/test/lib/Makefile
>     +++ b/test/lib/Makefile
>     @@ -25,6 +25,7 @@ obj-$(CONFIG_UT_LIB_ASN1) += asn1.o
>      obj-$(CONFIG_UT_LIB_RSA) += rsa.o
>      obj-$(CONFIG_AES) += test_aes.o
>      obj-$(CONFIG_SHA256) += test_sha256_hmac.o
>     +obj-$(CONFIG_HKDF_MBEDTLS) += test_sha256_hkdf.o
>      obj-$(CONFIG_GETOPT) += getopt.o
>      obj-$(CONFIG_CRC8) += test_crc8.o
>      obj-$(CONFIG_UT_LIB_CRYPT) += test_crypt.o
>     diff --git a/test/lib/test_sha256_hkdf.c b/test/lib/test_sha256_hkdf.c
>     new file mode 100644
>     index 00000000000..00090ffbc24
>     --- /dev/null
>     +++ b/test/lib/test_sha256_hkdf.c
>     @@ -0,0 +1,107 @@
>     +// SPDX-License-Identifier: GPL-2.0+
>     +/*
>     + * Copyright (c) 2024 Philippe Reynes
>     <philippe.reynes at softathome.com>
>     + *
>     + * Unit tests for sha256_hkdf functions
>     + */
>     +
>     +#include <command.h>
>     +#include <test/lib.h>
>     +#include <test/test.h>
>     +#include <test/ut.h>
>     +#include <u-boot/sha256.h>
>     +
>     +struct test_sha256_hkdf_s {
>     +       unsigned char *salt;
>     +       int saltlen;
>     +       unsigned char *ikm;
>     +       int ikmlen;
>     +       unsigned char *info;
>     +       int infolen;
>     +       unsigned char *expected;
>     +       int expectedlen;
>     +};
>     +
>     +/*
>     + * data comes from:
>     + * https://www.rfc-editor.org/rfc/rfc5869
>     <https://www.rfc-editor.org/rfc/rfc5869>
>     + */
>
>
> Shall we consider more test vectors for:
> Zero-length salt.
> Zero-length info.
> Maximum-length output.
>

I have added all tests from the RFC. So now, there is 3 tests.
The second test use longer input/output, and the third use
empty salt and info.


>     +static unsigned char salt_test1[] = {
>     +       0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
>     +       0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c };
>     +
>     +static unsigned char ikm_test1[] = {
>     +       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
>     0x0b, 0x0b,
>     +       0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
>     0x0b, 0x0b };
>     +
>     +static unsigned char info_test1[] = {
>     +       0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9 };
>     +
>     +static unsigned char expected_test1[] = {
>     +       0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a,
>     +       0x90, 0x43, 0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a,
>     +       0x2d, 0x2d, 0x0a, 0x90, 0xcf, 0x1a, 0x5a, 0x4c,
>     +       0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4, 0xc5, 0xbf,
>     +       0x34, 0x00, 0x72, 0x08, 0xd5, 0xb8, 0x87, 0x18,
>     +       0x58, 0x65 };
>     +
>     +static struct test_sha256_hkdf_s test_sha256_hkdf[] = {
>     +       {
>     +               .salt = salt_test1,
>     +               .saltlen = sizeof(salt_test1),
>     +               .ikm = ikm_test1,
>     +               .ikmlen = sizeof(ikm_test1),
>     +               .info = info_test1,
>     +               .infolen = sizeof(info_test1),
>     +               .expected = expected_test1,
>     +               .expectedlen = sizeof(expected_test1),
>     +       },
>     +};
>     +
>     +static int _lib_test_sha256_hkdf_run(struct unit_test_state *uts,
>     +                                    unsigned char *salt, int saltlen,
>     +                                    unsigned char *ikm, int ikmlen,
>     +                                    unsigned char *info, int infolen,
>     +                                    unsigned char *expected, int
>     expectedlen)
>     +{
>     +       unsigned char output[64];
>
>
> Please use SHA512_SUM_LEN to avoid magic numbers.


For the second test, I have increased this 64 to 256, as the output must 
be bigger than
the maximum output size of all tests.
I don't really know which constant I can use... so I have kept 256.


>     +       int ret;
>     +
>     +       ut_assert(expectedlen <= sizeof(output));
>     +       ret = sha256_hkdf(salt, saltlen, ikm, ikmlen, info,
>     infolen, output, expectedlen);
>     +       ut_assert(!ret);
>     +       ut_asserteq_mem(expected, output, expectedlen);
>     +
>     +       return 0;
>     +}
>     +
>     +static int lib_test_sha256_hkdf_run(struct unit_test_state *uts,
>     +                                   struct test_sha256_hkdf_s *test)
>     +{
>     +       unsigned char *salt = test->salt;
>     +       int saltlen = test->saltlen;
>     +       unsigned char *ikm = test->ikm;
>     +       int ikmlen = test->ikmlen;
>     +       unsigned char *info = test->info;
>     +       int infolen = test->infolen;
>     +       unsigned char *expected = test->expected;
>     +       int expectedlen = test->expectedlen;
>     +
>     +       return _lib_test_sha256_hkdf_run(uts, salt, saltlen, ikm,
>     ikmlen,
>     +                                        info, infolen, expected,
>     expectedlen);
>     +}
>     +
>     +static int lib_test_sha256_hkdf(struct unit_test_state *uts)
>     +{
>     +       int i, ret = 0;
>     +
>     +       for (i = 0; i < ARRAY_SIZE(test_sha256_hkdf); i++) {
>     +               ret = lib_test_sha256_hkdf_run(uts,
>     &test_sha256_hkdf[i]);
>     +               if (ret)
>     +                       break;
>     +       }
>     +
>     +       return ret;
>     +}
>     +
>     +LIB_TEST(lib_test_sha256_hkdf, 0);
>     -- 
>     2.25.1
>
>
> Regards,
> Raymond


btw, I have enabled mbedtls in the config sandbox to have at least one 
config with mbedtls and hkdf.


Regards,
Philippe