Hi Philippe,
On Thu, 12 Dec 2024 at 08:37, Philippe Reynes < philippe.reynes@softathome.com> wrote:
Adds the support of the hmac based on sha256. This implementation is based on rfc2104.
Signed-off-by: Philippe Reynes philippe.reynes@softathome.com
include/u-boot/sha256.h | 4 ++++ lib/sha256_common.c | 48 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+)
diff --git a/include/u-boot/sha256.h b/include/u-boot/sha256.h index 44a9b528b48..2f12275b703 100644 --- a/include/u-boot/sha256.h +++ b/include/u-boot/sha256.h @@ -45,4 +45,8 @@ void sha256_finish(sha256_context * ctx, uint8_t digest[SHA256_SUM_LEN]); void sha256_csum_wd(const unsigned char *input, unsigned int ilen, unsigned char *output, unsigned int chunk_sz);
+void sha256_hmac(const unsigned char *key, int keylen,
const unsigned char *input, unsigned int ilen,unsigned char *output);#endif /* _SHA256_H */ diff --git a/lib/sha256_common.c b/lib/sha256_common.c index 7041abd26d9..46262ea99a2 100644 --- a/lib/sha256_common.c +++ b/lib/sha256_common.c @@ -48,3 +48,51 @@ void sha256_csum_wd(const unsigned char *input, unsigned int ilen,
sha256_finish(&ctx, output);}
+void sha256_hmac(const unsigned char *key, int keylen,
const unsigned char *input, unsigned int ilen,unsigned char *output)+{
int i;sha256_context ctx;unsigned char keybuf[64];unsigned char k_ipad[64];unsigned char k_opad[64];unsigned char tmpbuf[32];int keybuf_len;if (keylen > 64) {sha256_starts(&ctx);sha256_update(&ctx, key, keylen);sha256_finish(&ctx, keybuf);keybuf_len = 32;} else {memcpy(keybuf, key, keylen);keybuf_len = keylen;}memset(k_ipad, 0x36, 64);memset(k_opad, 0x5C, 64);for (i = 0; i < keybuf_len; i++) {k_ipad[i] ^= keybuf[i];k_opad[i] ^= keybuf[i];}sha256_starts(&ctx);sha256_update(&ctx, k_ipad, sizeof(k_ipad));sha256_update(&ctx, input, ilen);sha256_finish(&ctx, tmpbuf);sha256_starts(&ctx);sha256_update(&ctx, k_opad, sizeof(k_opad));sha256_update(&ctx, tmpbuf, sizeof(tmpbuf));sha256_finish(&ctx, output);memset(k_ipad, 0, sizeof(k_ipad));memset(k_opad, 0, sizeof(k_opad));memset(tmpbuf, 0, sizeof(tmpbuf));memset(keybuf, 0, sizeof(keybuf));memset(&ctx, 0, sizeof(sha256_context));+}
2.25.1
The sha256 hmac common implementation now sounds good.
Do you have a comparison of performance with the MbedTLS high-level API mbedtls_md_hmac()? I am wondering if it is worth using this API specially when MbedTLS is enabled, since it significantly simplifies the implementation.
Regards, Raymond