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 {
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  NDN_THROW(Error(getIndex(), "Unsupported digest algorithm " + boost::lexical_cast<std::string>(algo)));
44 
45  if (EVP_DigestInit_ex(m_impl->ctx, md, nullptr) == 0)
46  NDN_THROW(Error(getIndex(), "Cannot initialize digest " + boost::lexical_cast<std::string>(algo)));
47 }
48 
49 DigestFilter::~DigestFilter() = default;
50 
51 size_t
52 DigestFilter::convert(span<const uint8_t> buf)
53 {
54  if (EVP_DigestUpdate(m_impl->ctx, buf.data(), buf.size()) == 0)
55  NDN_THROW(Error(getIndex(), "Failed to accept more input"));
56 
57  return buf.size();
58 }
59 
60 void
61 DigestFilter::finalize()
62 {
63  auto buffer = make_unique<OBuffer>(EVP_MAX_MD_SIZE);
64  unsigned int mdLen = 0;
65 
66  if (EVP_DigestFinal_ex(m_impl->ctx, buffer->data(), &mdLen) == 0)
67  NDN_THROW(Error(getIndex(), "Failed to finalize digest"));
68 
69  buffer->erase(buffer->begin() + mdLen, buffer->end());
70  setOutputBuffer(std::move(buffer));
71 
73 }
74 
75 unique_ptr<Transform>
77 {
78  return make_unique<DigestFilter>(algo);
79 }
80 
81 } // namespace transform
82 } // namespace security
83 } // namespace ndn
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:61
unique_ptr< Transform > digestFilter(DigestAlgorithm algo)
Definition: data.cpp:25