digest-filter.cpp
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21 
23 #include "ndn-cxx/security/impl/openssl-helper.hpp"
24 
25 #include <boost/lexical_cast.hpp>
26 
27 namespace ndn::security::transform {
28 
29 class DigestFilter::Impl
30 {
31 public:
32  detail::EvpMdCtx ctx;
33 };
34 
35 
37  : m_impl(make_unique<Impl>())
38 {
39  const EVP_MD* md = detail::digestAlgorithmToEvpMd(algo);
40  if (md == nullptr)
41  NDN_THROW(Error(getIndex(), "Unsupported digest algorithm " + boost::lexical_cast<std::string>(algo)));
42 
43  if (EVP_DigestInit_ex(m_impl->ctx, md, nullptr) == 0)
44  NDN_THROW(Error(getIndex(), "Cannot initialize digest " + boost::lexical_cast<std::string>(algo)));
45 }
46 
47 DigestFilter::~DigestFilter() = default;
48 
49 size_t
50 DigestFilter::convert(span<const uint8_t> buf)
51 {
52  if (EVP_DigestUpdate(m_impl->ctx, buf.data(), buf.size()) == 0)
53  NDN_THROW(Error(getIndex(), "Failed to accept more input"));
54 
55  return buf.size();
56 }
57 
58 void
59 DigestFilter::finalize()
60 {
61  auto buffer = make_unique<OBuffer>(EVP_MAX_MD_SIZE);
62  unsigned int mdLen = 0;
63 
64  if (EVP_DigestFinal_ex(m_impl->ctx, buffer->data(), &mdLen) == 0)
65  NDN_THROW(Error(getIndex(), "Failed to finalize digest"));
66 
67  buffer->erase(buffer->begin() + mdLen, buffer->end());
68  setOutputBuffer(std::move(buffer));
69 
71 }
72 
73 unique_ptr<Transform>
75 {
76  return make_unique<DigestFilter>(algo);
77 }
78 
79 } // namespace ndn::security::transform
DigestFilter(DigestAlgorithm algo)
Create a digest module with algorithm algo.
size_t getIndex() const
Get the module index.
Base class of transformation error.
void setOutputBuffer(unique_ptr< OBuffer > buffer)
Set output buffer to buffer.
void flushAllOutput()
Read the all the content from output buffer and write it into next module.
#define NDN_THROW(e)
Definition: exception.hpp:56
unique_ptr< Transform > digestFilter(DigestAlgorithm algo)