Hi Philippe,
On Mon, 9 Dec 2024 at 04:42, Philippe Reynes <philippe.rey...@softathome.com>
wrote:
> Adds the support of key derivation using the scheme hkdf.
> This scheme is defined in rfc5869.
>
> Signed-off-by: Philippe Reynes <philippe.rey...@softathome.com>
> ---
> include/u-boot/sha256.h | 7 +++++++
> lib/mbedtls/sha256.c | 22 ++++++++++++++++++++++
> 2 files changed, 29 insertions(+)
>
> diff --git a/include/u-boot/sha256.h b/include/u-boot/sha256.h
> index 2f12275b703..5643efcb85c 100644
> --- a/include/u-boot/sha256.h
> +++ b/include/u-boot/sha256.h
> @@ -49,4 +49,11 @@ void sha256_hmac(const unsigned char *key, int keylen,
> const unsigned char *input, unsigned int ilen,
> unsigned char *output);
>
> +#if defined(CONFIG_HKDF_MBEDTLS)
> +int sha256_hkdf(const unsigned char *salt, int saltlen,
> + const unsigned char *ikm, int ikmlen,
> + const unsigned char *info, int infolen,
> + unsigned char *output, int outputlen);
> +#endif
> +
>
I think this will be better:
#if CONFIG_IS_ENABLED(HKDF_MBEDTLS)
int sha256_hkdf(const unsigned char *salt, int saltlen,
const unsigned char *ikm, int ikmlen,
const unsigned char *info, int infolen,
unsigned char *output, int outputlen);
#else
static inline int sha256_hkdf(const unsigned char __always_unused *salt,
int __always_unused saltlen,
const unsigned char __always_unused *ikm,
int __always_unused ikmlen,
const unsigned char __always_unused *info,
int __always_unused infolen,
unsigned char __always_unused *output,
int __always_unused outputlen) {
return -EOPNOTSUPP;
}
#endif
> #endif /* _SHA256_H */
> diff --git a/lib/mbedtls/sha256.c b/lib/mbedtls/sha256.c
> index 1b9fc1a8503..6e9659d31bb 100644
> --- a/lib/mbedtls/sha256.c
> +++ b/lib/mbedtls/sha256.c
> @@ -11,6 +11,11 @@
> #include <string.h>
> #include <u-boot/sha256.h>
>
> +#if CONFIG_IS_ENABLED(HKDF_MBEDTLS)
> +#include <mbedtls/md.h>
> +#include <mbedtls/hkdf.h>
> +#endif
> +
> const u8 sha256_der_prefix[SHA256_DER_LEN] = {
> 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
> 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05,
> @@ -98,3 +103,20 @@ void sha256_hmac(const unsigned char *key, int keylen,
> memset(tmpbuf, 0, sizeof(tmpbuf));
> memset(&ctx, 0, sizeof(sha256_context));
> }
> +
> +#if CONFIG_IS_ENABLED(HKDF_MBEDTLS)
> +int sha256_hkdf(const unsigned char *salt, int saltlen,
> + const unsigned char *ikm, int ikmlen,
> + const unsigned char *info, int infolen,
> + unsigned char *output, int outputlen)
> +{
> + const mbedtls_md_info_t *md;
> +
> + md = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
> +
> + return mbedtls_hkdf(md, salt, saltlen,
> + ikm, ikmlen,
> + info, infolen,
> + output, outputlen);
> +}
> +#endif
> --
> 2.25.1
>
>
