NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.3: NDN, CCN, CCNx, content centric networks
API Documentation
sha256.cpp
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21 
22 #include "sha256.hpp"
23 #include "string-helper.hpp"
24 #include "../security/detail/openssl.hpp"
25 #include "../security/transform/digest-filter.hpp"
26 #include "../security/transform/stream-sink.hpp"
27 #include "../security/transform/stream-source.hpp"
28 
29 namespace ndn {
30 namespace util {
31 
32 const size_t Sha256::DIGEST_SIZE;
33 
35 {
36  reset();
37 }
38 
39 Sha256::Sha256(std::istream& is)
40  : m_output(make_unique<OBufferStream>())
41  , m_isEmpty(false)
42  , m_isFinalized(true)
43 {
44  namespace tr = security::transform;
45 
47 }
48 
49 void
51 {
52  namespace tr = security::transform;
53 
54  m_input = make_unique<tr::StepSource>();
55  m_output = make_unique<OBufferStream>();
56  m_isEmpty = true;
57  m_isFinalized = false;
58 
59  *m_input >> tr::digestFilter(DigestAlgorithm::SHA256) >> tr::streamSink(*m_output);
60 }
61 
64 {
65  if (!m_isFinalized) {
66  BOOST_ASSERT(m_input != nullptr);
67  m_input->end();
68  m_isFinalized = true;
69  }
70 
71  return m_output->buf();
72 }
73 
74 bool
76 {
77  const Buffer& lhs = *computeDigest();
78  const Buffer& rhs = *digest.computeDigest();
79 
80  if (lhs.size() != rhs.size()) {
81  return false;
82  }
83 
84  // constant-time buffer comparison to mitigate timing attacks
85  return CRYPTO_memcmp(lhs.data(), rhs.data(), lhs.size()) == 0;
86 }
87 
88 Sha256&
90 {
91  auto buf = src.computeDigest();
92  update(buf->data(), buf->size());
93  return *this;
94 }
95 
96 Sha256&
97 Sha256::operator<<(const std::string& str)
98 {
99  update(reinterpret_cast<const uint8_t*>(str.data()), str.size());
100  return *this;
101 }
102 
103 Sha256&
105 {
106  update(block.wire(), block.size());
107  return *this;
108 }
109 
110 Sha256&
112 {
113  update(reinterpret_cast<const uint8_t*>(&value), sizeof(uint64_t));
114  return *this;
115 }
116 
117 void
118 Sha256::update(const uint8_t* buffer, size_t size)
119 {
120  if (m_isFinalized)
121  BOOST_THROW_EXCEPTION(Error("Digest has been already finalized"));
122 
123  BOOST_ASSERT(m_input != nullptr);
124  m_input->write(buffer, size);
125  m_isEmpty = false;
126 }
127 
128 std::string
130 {
131  auto buf = computeDigest();
132  return toHex(*buf);
133 }
134 
136 Sha256::computeDigest(const uint8_t* buffer, size_t size)
137 {
138  Sha256 sha256;
139  sha256.update(buffer, size);
140  return sha256.computeDigest();
141 }
142 
143 std::ostream&
144 operator<<(std::ostream& os, Sha256& digest)
145 {
146  auto buf = digest.computeDigest();
147  printHex(os, *buf);
148  return os;
149 }
150 
151 } // namespace util
152 } // namespace ndn
Copyright (c) 2011-2015 Regents of the University of California.
Provides stateful SHA-256 digest calculation.
Definition: sha256.hpp:44
std::string toHex(const uint8_t *buffer, size_t length, bool wantUpperCase)
Return a string containing the hex representation of the bytes in buffer.
static const size_t DIGEST_SIZE
Length in bytes of a SHA-256 digest.
Definition: sha256.hpp:60
unique_ptr< T > make_unique(Args &&...args)
Definition: backports.hpp:73
bool operator==(Sha256 &digest)
Check if the supplied digest is equal to this digest.
Definition: sha256.cpp:75
Represents a TLV element of NDN packet format.
Definition: block.hpp:42
std::string toString()
Convert digest to std::string.
Definition: sha256.cpp:129
Sha256()
Create an empty SHA-256 digest.
Definition: sha256.cpp:34
void update(const uint8_t *buffer, size_t size)
Add a raw buffer to the digest calculation.
Definition: sha256.cpp:118
size_t size() const
Get size of encoded wire, including Type-Length-Value.
Definition: block.cpp:299
void reset()
Discard the current state and start a new digest calculation.
Definition: sha256.cpp:50
unique_ptr< Sink > streamSink(std::ostream &os)
Definition: stream-sink.cpp:53
unique_ptr< Transform > digestFilter(DigestAlgorithm algo)
Use the SHA256 hash of the public key as the key id.
const uint8_t * wire() const
Get pointer to encoded wire.
Definition: block.cpp:290
ConstBufferPtr computeDigest()
Finalize and return the digest based on all previously supplied inputs.
Definition: sha256.cpp:63
void printHex(std::ostream &os, uint64_t num, bool wantUpperCase)
Output the hex representation of num to the output stream os.
implements an output stream that constructs ndn::Buffer
Sha256 & operator<<(Sha256 &src)
Add existing digest to the digest calculation.
Definition: sha256.cpp:89
General-purpose automatically managed/resized buffer.
Definition: buffer.hpp:40
shared_ptr< const Buffer > ConstBufferPtr
Definition: buffer.hpp:89