hmac.

src/main/scala/sha256/Hmac.scala

@@ -0,0 +1,55 @@
+package sha256
+
+import scala.scalanative.libc.stdlib
+import scala.scalanative.libc.string
+import scala.scalanative.unsafe._
+import scala.scalanative.unsigned._
+
+object Hmac {
+  def hmac(
+      key: Array[UByte],
+      msg: Array[UByte]
+  ): Array[UByte] = {
+    Zone { implicit z =>
+      {
+        val keySize = key.size.toLong.toULong
+        val keyData = alloc[UByte](keySize).asInstanceOf[Ptr[UByte]]
+        for (i <- 0 until key.size) {
+          !(keyData + i) = key(i)
+        }
+
+        val msgSize = msg.size.toLong.toULong
+        val msgData = alloc[UByte](msgSize).asInstanceOf[Ptr[UByte]]
+        for (i <- 0 until msg.size) {
+          !(msgData + i) = msg(i)
+        }
+
+        val result = alloc[UByte](32).asInstanceOf[Ptr[UByte]]
+        HmacExtern.hmac_sha256(
+          result,
+          keyData,
+          keySize,
+          msgData,
+          msgSize
+        )
+
+        val res = Array.ofDim[UByte](32)
+        for (i <- 0 until 32) {
+          res(i) = (!(result + i)).toUByte
+        }
+        res
+      }
+    }
+  }
+}
+
+@extern
+object HmacExtern {
+  def hmac_sha256(
+      hmac: Ptr[UByte],
+      k: Ptr[UByte],
+      ksize: CSize,
+      d: Ptr[UByte],
+      dsize: CSize
+  ): Unit = extern
+}

src/test/scala/Test.scala

@@ -1,6 +1,6 @@
 import scala.scalanative.unsigned._
 import utest._
-import sha256.{Sha256, Hkdf}
+import sha256.{Sha256, Hkdf, Hmac}
 
 object Sha256EtcTests extends TestSuite {
   def bytes2hex(ba: Array[UByte]): String =
@@ -69,5 +69,16 @@ object Sha256EtcTests extends TestSuite {
         r
       ) ==> "a754786431d51674edc4f04a568a55f37b996db70fa2a795b15e2ea57cfed8be"
     }
+
+    test("hmac") {
+      val key = "abcdef".getBytes.map(_.toUByte)
+      val msg = "123456".getBytes.map(_.toUByte)
+
+      val r = Hmac.hmac(key, msg)
+      r.size ==> 32
+      bytes2hex(
+        r
+      ) ==> "ec4a11a5568e5cfdb5fbfe7152e8920d7bad864a0645c57fe49046a3e81ec91d"
+    }
   }
 }