digest-filter.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2013-2017 Regents of the University of California.
4  *
5  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
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17  * <http://www.gnu.org/licenses/>.
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19  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
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21 
22 #include "digest-filter.hpp"
23 #include "../detail/openssl-helper.hpp"
24 
25 #include <boost/lexical_cast.hpp>
26 
27 namespace ndn {
28 namespace security {
29 namespace transform {
30 
31 class DigestFilter::Impl
32 {
33 public:
34  detail::EvpMdCtx ctx;
35 };
36 
37 
39  : m_impl(make_unique<Impl>())
40 {
41  const EVP_MD* md = detail::digestAlgorithmToEvpMd(algo);
42  if (md == nullptr)
43  BOOST_THROW_EXCEPTION(Error(getIndex(), "Unsupported digest algorithm " +
44  boost::lexical_cast<std::string>(algo)));
45 
46  if (EVP_DigestInit_ex(m_impl->ctx, md, nullptr) == 0)
47  BOOST_THROW_EXCEPTION(Error(getIndex(), "Cannot initialize digest " +
48  boost::lexical_cast<std::string>(algo)));
49 }
50 
51 DigestFilter::~DigestFilter() = default;
52 
53 size_t
54 DigestFilter::convert(const uint8_t* buf, size_t size)
55 {
56  if (EVP_DigestUpdate(m_impl->ctx, buf, size) == 0)
57  BOOST_THROW_EXCEPTION(Error(getIndex(), "Failed to accept more input"));
58 
59  return size;
60 }
61 
62 void
63 DigestFilter::finalize()
64 {
65  auto buffer = make_unique<OBuffer>(EVP_MAX_MD_SIZE);
66  unsigned int mdLen = 0;
67 
68  if (EVP_DigestFinal_ex(m_impl->ctx, buffer->data(), &mdLen) == 0)
69  BOOST_THROW_EXCEPTION(Error(getIndex(), "Failed to finalize digest"));
70 
71  buffer->erase(buffer->begin() + mdLen, buffer->end());
72  setOutputBuffer(std::move(buffer));
73 
75 }
76 
77 unique_ptr<Transform>
79 {
80  return make_unique<DigestFilter>(algo);
81 }
82 
83 } // namespace transform
84 } // namespace security
85 } // namespace ndn
Copyright (c) 2013-2017 Regents of the University of California.
Definition: common.hpp:66
DigestFilter(DigestAlgorithm algo)
Create a digest module with algorithm algo.
unique_ptr< T > make_unique(Args &&...args)
Definition: backports.hpp:73
void flushAllOutput()
Read the all the content from output buffer and write it into next module.
void setOutputBuffer(unique_ptr< OBuffer > buffer)
Set output buffer to buffer.
unique_ptr< Transform > digestFilter(DigestAlgorithm algo)
Base class of transformation error.
size_t getIndex() const
Get the module index.