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/mbedtls/sha256.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+)
diff --git a/include/u-boot/sha256.h b/include/u-boot/sha256.h index b58d5b58d39..77dbcd4553a 100644 --- a/include/u-boot/sha256.h +++ b/include/u-boot/sha256.h @@ -44,4 +44,8 @@ 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/mbedtls/sha256.c b/lib/mbedtls/sha256.c index 24aa58fa674..1b9fc1a8503 100644 --- a/lib/mbedtls/sha256.c +++ b/lib/mbedtls/sha256.c @@ -8,6 +8,7 @@ #ifndef USE_HOSTCC #include <cyclic.h> #endif /* USE_HOSTCC */ +#include <string.h> #include <u-boot/sha256.h>
const u8 sha256_der_prefix[SHA256_DER_LEN] = { @@ -60,3 +61,40 @@ 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 k_ipad[64]; + unsigned char k_opad[64]; + unsigned char tmpbuf[32]; + + memset(k_ipad, 0x36, 64); + memset(k_opad, 0x5C, 64); + + for (i = 0; i < keylen; i++) { + if (i >= 64) + break; + + k_ipad[i] ^= key[i]; + k_opad[i] ^= key[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(&ctx, 0, sizeof(sha256_context)); +}