diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/sha256.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/lib/sha256.c b/lib/sha256.c index 7f5a3618d0..f9b6bce72e 100644 --- a/lib/sha256.c +++ b/lib/sha256.c @@ -290,3 +290,43 @@ 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)); +} |