diff --git a/src/commonMain/kotlin/com/infendro/hash/util/Buffer.kt b/src/commonMain/kotlin/com/infendro/hash/Buffer.kt
similarity index 79%
rename from src/commonMain/kotlin/com/infendro/hash/util/Buffer.kt
rename to src/commonMain/kotlin/com/infendro/hash/Buffer.kt
index 7f35e10..81ae8ee 100644
--- a/src/commonMain/kotlin/com/infendro/hash/util/Buffer.kt
+++ b/src/commonMain/kotlin/com/infendro/hash/Buffer.kt
@@ -1,11 +1,12 @@
-package com.infendro.hash.util
+package com.infendro.hash
 
 import com.infendro.bytes.ByteOrder
-import com.infendro.bytes.ByteOrder.BIG_ENDIAN
 import com.infendro.bytes.int.copyInto
 import com.infendro.bytes.long.copyInto
 
-internal class Buffer(val size: Int) {
+class Buffer(
+    val size: Int,
+) {
     val value = ByteArray(size)
     var offset = 0
 
@@ -34,12 +35,12 @@ internal class Buffer(val size: Int) {
         offset += (endIndex - startIndex)
     }
 
-    fun append(n: Int, order: ByteOrder = BIG_ENDIAN) {
+    fun append(n: Int, order: ByteOrder = ByteOrder.BIG_ENDIAN) {
         n.copyInto(value, offset, order = order)
         offset += 4
     }
 
-    fun append(n: Long, order: ByteOrder = BIG_ENDIAN) {
+    fun append(n: Long, order: ByteOrder = ByteOrder.BIG_ENDIAN) {
         n.copyInto(value, offset, order = order)
         offset += 8
     }
diff --git a/src/commonMain/kotlin/com/infendro/hash/HashFunction.kt b/src/commonMain/kotlin/com/infendro/hash/HashFunction.kt
index ccf72ba..d9acd6b 100644
--- a/src/commonMain/kotlin/com/infendro/hash/HashFunction.kt
+++ b/src/commonMain/kotlin/com/infendro/hash/HashFunction.kt
@@ -1,7 +1,5 @@
 package com.infendro.hash
 
-import com.infendro.hash.util.Buffer
-
 abstract class HashFunction(
     val bytes: Int,
     val block: Int,
@@ -9,8 +7,8 @@ abstract class HashFunction(
     val bits: Int
         get() = bytes * 8
 
-    internal val buffer = Buffer(block)
-    internal var length = 0L
+    protected val buffer = Buffer(block)
+    protected var length = 0L
 
     open fun reset() {
         buffer.reset()
@@ -29,28 +27,18 @@ abstract class HashFunction(
     open fun update(bytes: ByteArray) {
         var i = 0
 
-        // (partial) first block
-        val free = buffer.free
-        if (i + free < bytes.size) {
+        var free = buffer.free
+        while (i + free < bytes.size) {
             buffer.append(bytes, startIndex = i, endIndex = i + free)
             length += free
             process()
             buffer.reset()
-            i += free
-        }
-
-        // full blocks
-        while (i + block < bytes.size) {
-            buffer.append(bytes, startIndex = i, endIndex = i + block)
-            length += block
-            process()
-            buffer.reset()
+            free = buffer.free
             i += block
         }
 
-        // (partial) last block
         buffer.append(bytes, startIndex = i)
-        length += bytes.size - i
+        length += (bytes.size - i)
         if (buffer.isFull()) {
             process()
             buffer.reset()
diff --git a/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2b.kt b/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2b.kt
index e0db34b..3ec27a2 100644
--- a/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2b.kt
+++ b/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2b.kt
@@ -38,15 +38,21 @@ class Blake2b(bytes: Int) : HashFunction(bytes, 128) {
             process()
             buffer.reset()
         }
+
         var i = 0
-        while (i + buffer.free < bytes.size) {
-            val remaining = buffer.free
-            buffer.append(bytes, startIndex = i, endIndex = i + remaining)
+
+        var free = buffer.free
+        while (i + free < bytes.size) {
+            buffer.append(bytes, startIndex = i, endIndex = i + free)
+            length += free
             process()
             buffer.reset()
-            i += remaining
+            free = buffer.free
+            i += block
         }
+
         buffer.append(bytes, startIndex = i)
+        length += (bytes.size - i)
     }
 
     override fun process() = compress(buffer.value, length, false)
diff --git a/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2s.kt b/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2s.kt
index ed8c74d..64d3830 100644
--- a/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2s.kt
+++ b/src/commonMain/kotlin/com/infendro/hash/blake2/Blake2s.kt
@@ -38,15 +38,21 @@ class Blake2s(bytes: Int) : HashFunction(bytes, 64) {
             process()
             buffer.reset()
         }
+
         var i = 0
-        while (i + buffer.free < bytes.size) {
-            val remaining = buffer.free
-            buffer.append(bytes, startIndex = i, endIndex = i + remaining)
+
+        var free = buffer.free
+        while (i + free < bytes.size) {
+            buffer.append(bytes, startIndex = i, endIndex = i + free)
+            length += free
             process()
             buffer.reset()
-            i += remaining
+            free = buffer.free
+            i += block
         }
+
         buffer.append(bytes, startIndex = i)
+        length += (bytes.size - i)
     }
 
     override fun process() = compress(buffer.value, length, false)