1 files changed, 82 insertions, 0 deletions
diff --git a/include/llvm/Support/SHA1.h b/include/llvm/Support/SHA1.h
new file mode 100644
index 0000000000000..8347a713f2724
--- /dev/null
+++ b/include/llvm/Support/SHA1.h
@@ -0,0 +1,82 @@
+//==- SHA1.h - SHA1 implementation for LLVM                     --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This code is taken from public domain
+// (http://oauth.googlecode.com/svn/code/c/liboauth/src/sha1.c)
+// and modified by wrapping it in a C++ interface for LLVM,
+// and removing unnecessary code.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_SHA1_H
+#define LLVM_SUPPORT_SHA1_H
+
+#include "llvm/ADT/ArrayRef.h"
+
+#include <cstdint>
+
+namespace llvm {
+template <typename T> class ArrayRef;
+class StringRef;
+
+/// A class that wrap the SHA1 algorithm.
+class SHA1 {
+public:
+  SHA1() { init(); }
+
+  /// Reinitialize the internal state
+  void init();
+
+  /// Digest more data.
+  void update(ArrayRef<uint8_t> Data);
+
+  /// Digest more data.
+  void update(StringRef Str) {
+    update(ArrayRef<uint8_t>((uint8_t *)const_cast<char *>(Str.data()),
+                             Str.size()));
+  }
+
+  /// Return a reference to the current raw 160-bits SHA1 for the digested data
+  /// since the last call to init(). This call will add data to the internal
+  /// state and as such is not suited for getting an intermediate result
+  /// (see result()).
+  StringRef final();
+
+  /// Return a reference to the current raw 160-bits SHA1 for the digested data
+  /// since the last call to init(). This is suitable for getting the SHA1 at
+  /// any time without invalidating the internal state so that more calls can be
+  /// made into update.
+  StringRef result();
+
+private:
+  /// Define some constants.
+  /// "static constexpr" would be cleaner but MSVC does not support it yet.
+  enum { BLOCK_LENGTH = 64 };
+  enum { HASH_LENGTH = 20 };
+
+  // Internal State
+  struct {
+    uint32_t Buffer[BLOCK_LENGTH / 4];
+    uint32_t State[HASH_LENGTH / 4];
+    uint32_t ByteCount;
+    uint8_t BufferOffset;
+  } InternalState;
+
+  // Internal copy of the hash, populated and accessed on calls to result()
+  uint32_t HashResult[HASH_LENGTH / 4];
+
+  // Helper
+  void writebyte(uint8_t data);
+  void hashBlock();
+  void addUncounted(uint8_t data);
+  void pad();
+};
+
+} // end llvm namespace
+
+#endif