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// Copyright 2014 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Provides a fast MD5 implementation.
//
// This implementation saves us from linking huge OpenSSL library.
#ifndef BAZEL_SRC_MAIN_CPP_UTIL_MD5_H_
#define BAZEL_SRC_MAIN_CPP_UTIL_MD5_H_
#include <string>
#if defined(_MSC_VER) && !defined(__alignof__)
#define __alignof__ __alignof
#endif // _MSC_VER && !__alignof__
#if defined(__linux__)
#include <endian.h>
#elif defined(__FreeBSD__) || defined(__OpenBSD__)
#include <sys/endian.h>
#elif defined(__APPLE__) || defined(_WIN32)
// Hopefully OSX and Windows will keep running solely on little endian CPUs, so:
#define htole32(x) (x)
#endif
namespace blaze_util {
// The <code>Context</code> class performs the actual MD5
// computation. It works incrementally and can be fed a single byte at
// a time if desired.
class Md5Digest {
public:
Md5Digest();
Md5Digest(const Md5Digest& original);
// the MD5 digest is always 128 bits = 16 bytes
static constexpr int kDigestLength = 16;
// Resets the context so that it can be used to calculate another
// MD5 digest. The context is in the same state as if it had just
// been constructed. It is unnecessary to call <code>Reset</code> on
// a newly created context.
void Reset();
// Add <code>length</code> bytes of <code>buf</code> to the MD5
// digest.
void Update(const void *buf, unsigned int length);
// Retrieve the computed MD5 digest as a 16 byte array.
void Finish(unsigned char* digest);
// Produces a hexadecimal string representation of this digest in the form:
// [0-9a-f]{32}
std::string String() const;
private:
void Transform(const unsigned char* buffer, unsigned int len);
private:
unsigned int state[4]; // state (ABCD)
unsigned int count[2]; // number of bits, modulo 2^64 (lsb first)
unsigned char ctx_buffer[128]; // input buffer
unsigned int ctx_buffer_len;
};
} // namespace blaze_util
#endif // BAZEL_SRC_MAIN_CPP_UTIL_MD5_H_