still wip

User/lib/cifra/hmac.c

@@ -17,6 +17,7 @@
 #include "bitops.h"
 #include "handy.h"
 #include "tassert.h"
+#include "sha2.h"
 
 #include <string.h>
 
@@ -104,3 +105,13 @@ void cf_hmac(const uint8_t *key, size_t nkey,
   cf_hmac_finish(&ctx, out);
 }
 
+// HMAC-SHA256
+int hmac_sha256 (const uint8_t *key, size_t keylen,
+                 const uint8_t *input, size_t ilen,
+                 uint8_t *output) {
+    cf_hmac_ctx ctx;
+    cf_hmac_init (&ctx, &cf_sha256, key, keylen);
+    cf_hmac_update (&ctx, input, ilen);
+    cf_hmac_finish (&ctx, output);
+    return 0;
+}