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)); +}