diff -r 000000000000 -r 6474c204b198 mfbt/SHA1.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mfbt/SHA1.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Simple class for computing SHA1. */
+
+#ifndef mozilla_SHA1_h
+#define mozilla_SHA1_h
+
+#include "mozilla/Types.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace mozilla {
+
+/**
+ * This class computes the SHA1 hash of a byte sequence, or of the concatenation
+ * of multiple sequences.  For example, computing the SHA1 of two sequences of
+ * bytes could be done as follows:
+ *
+ *   void SHA1(const uint8_t* buf1, uint32_t size1,
+ *             const uint8_t* buf2, uint32_t size2,
+ *             SHA1Sum::Hash& hash)
+ *   {
+ *     SHA1Sum s;
+ *     s.update(buf1, size1);
+ *     s.update(buf2, size2);
+ *     s.finish(hash);
+ *   }
+ *
+ * The finish method may only be called once and cannot be followed by calls
+ * to update.
+ */
+class SHA1Sum
+{
+    union {
+        uint32_t w[16]; /* input buffer */
+        uint8_t b[64];
+    } u;
+    uint64_t size; /* count of hashed bytes. */
+    unsigned H[22]; /* 5 state variables, 16 tmp values, 1 extra */
+    bool mDone;
+
+  public:
+    MFBT_API SHA1Sum();
+
+    static const size_t HashSize = 20;
+    typedef uint8_t Hash[HashSize];
+
+    /* Add len bytes of dataIn to the data sequence being hashed. */
+    MFBT_API void update(const void* dataIn, uint32_t len);
+
+    /* Compute the final hash of all data into hashOut. */
+    MFBT_API void finish(SHA1Sum::Hash& hashOut);
+};
+
+} /* namespace mozilla */
+
+#endif /* mozilla_SHA1_h */