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.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 44 insertions(+)
diff --git a/include/u-boot/sha256.h b/include/u-boot/sha256.h index a4fe176c0b4..7aa4c54d0d4 100644 --- a/include/u-boot/sha256.h +++ b/include/u-boot/sha256.h @@ -24,4 +24,8 @@ 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.c b/lib/sha256.c index 665ba6f152e..64f6b48974b 100644 --- a/lib/sha256.c +++ b/lib/sha256.c @@ -298,3 +298,43 @@ void sha256_csum_wd(const unsigned char *input, unsigned int ilen,
sha256_finish(&ctx, output); } + +/* + * Output = HMAC-SHA-256( input buffer, hmac key ) + */ +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, 64); + sha256_update(&ctx, input, ilen); + sha256_finish(&ctx, tmpbuf); + + sha256_starts(&ctx); + sha256_update(&ctx, k_opad, 64); + sha256_update(&ctx, tmpbuf, 32); + sha256_finish(&ctx, output); + + memset(k_ipad, 0, 64); + memset(k_opad, 0, 64); + memset(tmpbuf, 0, 32); + memset(&ctx, 0, sizeof(sha256_context)); +}