1/*
2 *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef WEBRTC_BASE_OPENSSLDIGEST_H_
12#define WEBRTC_BASE_OPENSSLDIGEST_H_
13
14#include <openssl/evp.h>
15
16#include "webrtc/base/messagedigest.h"
17
18namespace rtc {
19
20// An implementation of the digest class that uses OpenSSL.
21class OpenSSLDigest : public MessageDigest {
22 public:
23  // Creates an OpenSSLDigest with |algorithm| as the hash algorithm.
24  explicit OpenSSLDigest(const std::string& algorithm);
25  ~OpenSSLDigest();
26  // Returns the digest output size (e.g. 16 bytes for MD5).
27  virtual size_t Size() const;
28  // Updates the digest with |len| bytes from |buf|.
29  virtual void Update(const void* buf, size_t len);
30  // Outputs the digest value to |buf| with length |len|.
31  virtual size_t Finish(void* buf, size_t len);
32
33  // Helper function to look up a digest's EVP by name.
34  static bool GetDigestEVP(const std::string &algorithm,
35                           const EVP_MD** md);
36  // Helper function to look up a digest's name by EVP.
37  static bool GetDigestName(const EVP_MD* md,
38                            std::string* algorithm);
39  // Helper function to get the length of a digest.
40  static bool GetDigestSize(const std::string &algorithm,
41                            size_t* len);
42
43 private:
44  EVP_MD_CTX ctx_;
45  const EVP_MD* md_;
46};
47
48}  // namespace rtc
49
50#endif  // WEBRTC_BASE_OPENSSLDIGEST_H_
51