diff --git a/saco/checksums.cpp b/saco/checksums.cpp
new file mode 100644
index 0000000..a8a53a7
--- /dev/null
+++ b/saco/checksums.cpp
@@ -0,0 +1,23 @@
+
+#include <stdio.h>
+#include <windows.h>
+#include "fhicl-sha1.h"
+
+//----------------------------------------------------------
+
+void SHA1_HashData(PCHAR szData, DWORD dwLen, DWORD *pdwDigest)
+{
+	fhicl::SHA1 sha1;
+
+	for(int i = 0; i < 5; i++) {
+		pdwDigest[i] = 0;
+	}
+
+	if(!IsBadReadPtr(szData, dwLen))
+	{
+		sha1.Input(szData, dwLen);
+		sha1.Result((unsigned int*)pdwDigest);
+	}
+}
+
+//----------------------------------------------------------
diff --git a/saco/checksums.h b/saco/checksums.h
new file mode 100644
index 0000000..3abebaf
--- /dev/null
+++ b/saco/checksums.h
@@ -0,0 +1,8 @@
+
+#pragma once
+
+//----------------------------------------------------------
+
+void SHA1_HashData(PCHAR szData, DWORD dwLen, DWORD *pdwDigest);
+
+//----------------------------------------------------------
diff --git a/saco/saco.vcproj b/saco/saco.vcproj
index 253c1b6..4d01a8d 100644
--- a/saco/saco.vcproj
+++ b/saco/saco.vcproj
@@ -544,6 +544,12 @@
 		<File
 			RelativePath=".\chatwindow.h">
 		</File>
+		<File
+			RelativePath=".\checksums.cpp">
+		</File>
+		<File
+			RelativePath=".\checksums.h">
+		</File>
 		<File
 			RelativePath=".\cmdprocs.cpp">
 		</File>