fizz::KeyDerivationImpl< Hash > Class Template Reference

#include <KeyDerivation.h>

Inheritance diagram for fizz::KeyDerivationImpl< Hash >:

Public Member Functions
	~KeyDerivationImpl () override=default
	KeyDerivationImpl (const std::string &labelPrefix)
size_t	hashLength () const override
void	hash (const folly::IOBuf &in, folly::MutableByteRange out) override
void	hmac (folly::ByteRange key, const folly::IOBuf &in, folly::MutableByteRange out) override
folly::ByteRange	blankHash () const override
Buf	expandLabel (folly::ByteRange secret, folly::StringPiece label, Buf hashValue, uint16_t length) override
std::vector< uint8_t >	deriveSecret (folly::ByteRange secret, folly::StringPiece label, folly::ByteRange messageHash) override
virtual Buf	hkdfExpand (folly::ByteRange secret, Buf info, uint16_t length) override
std::vector< uint8_t >	hkdfExtract (folly::ByteRange salt, folly::ByteRange ikm) override
Public Member Functions inherited from fizz::KeyDerivation
virtual	~KeyDerivation ()=default

Private Attributes
std::string	labelPrefix_

Detailed Description

template<typename Hash>
class fizz::KeyDerivationImpl< Hash >

Definition at line 60 of file KeyDerivation.h.

Constructor & Destructor Documentation

template<typename Hash>

fizz::KeyDerivationImpl< Hash >::~KeyDerivationImpl ( )

overridedefault

template<typename Hash >

fizz::KeyDerivationImpl< Hash >::KeyDerivationImpl

(

const std::string &

labelPrefix

)

Definition at line 12 of file KeyDerivation-inl.h.

    : labelPrefix_(labelPrefix) {}

Member Function Documentation

template<typename Hash>

folly::ByteRange fizz::KeyDerivationImpl< Hash >::blankHash ( ) const

inlineoverridevirtual

Returns the hash of a blank input (ie Hash("")).

Implements fizz::KeyDerivation.

Definition at line 81 of file KeyDerivation.h.

References fizz::KeyDerivation::deriveSecret(), fizz::KeyDerivation::expandLabel(), fizz::KeyDerivation::hkdfExpand(), deadlock::info(), fizz::test::label, secret, and uint16_t.

                                            {
    return Hash::BlankHash;
  }

template<typename Hash >

std::vector< uint8_t > fizz::KeyDerivationImpl< Hash >::deriveSecret ( folly::ByteRange  secret, folly::StringPiece  label, folly::ByteRange  messageHash  )

overridevirtual

Implements fizz::KeyDerivation.

Definition at line 36 of file KeyDerivation-inl.h.

References folly::IOBuf::copyBuffer(), fizz::KeyDerivationImpl< Hash >::expandLabel(), min, folly::gen::move, and folly::Range< Iter >::size().

                                {
  CHECK_EQ(secret.size(), Hash::HashLen);
  CHECK_EQ(messageHash.size(), Hash::HashLen);
  // Copying the buffer to avoid violating constness of the data.
  auto hashBuf = folly::IOBuf::copyBuffer(messageHash);
  auto out = expandLabel(secret, label, std::move(hashBuf), Hash::HashLen);
  std::vector<uint8_t> prk(Hash::HashLen);
  size_t offset = 0;
  for (auto buf : *out) {
    size_t remaining = Hash::HashLen - offset;
    size_t length = std::min(buf.size(), remaining);
    memcpy(prk.data() + offset, buf.data(), length);
    offset += length;
  }
  return prk;
}

template<typename Hash >

Buf fizz::KeyDerivationImpl< Hash >::expandLabel ( folly::ByteRange  secret, folly::StringPiece  label, Buf  hashValue, uint16_t  length  )

overridevirtual

Implements fizz::KeyDerivation.

Definition at line 16 of file KeyDerivation-inl.h.

References folly::Range< Iter >::begin(), fizz::encodeHkdfLabel(), folly::Range< Iter >::end(), fizz::KeyDerivationImpl< Hash >::labelPrefix_, folly::gen::move, and string.

Referenced by fizz::KeyDerivationImpl< Hash >::deriveSecret().

                     {
  HkdfLabel hkdfLabel = {
      length, std::string(label.begin(), label.end()), std::move(hashValue)};
  return HkdfImpl<Hash>().expand(
      secret, *encodeHkdfLabel(std::move(hkdfLabel), labelPrefix_), length);
}

template<typename Hash>

void fizz::KeyDerivationImpl< Hash >::hash ( const folly::IOBuf &  in, folly::MutableByteRange  out  )

inlineoverridevirtual

Implements fizz::KeyDerivation.

Definition at line 70 of file KeyDerivation.h.

                                                                      {
    Hash::hash(in, out);
  }

template<typename Hash>

size_t fizz::KeyDerivationImpl< Hash >::hashLength ( ) const

inlineoverridevirtual

Implements fizz::KeyDerivation.

Definition at line 66 of file KeyDerivation.h.

                                     {
    return Hash::HashLen;
  }

template<typename Hash >

Buf fizz::KeyDerivationImpl< Hash >::hkdfExpand ( folly::ByteRange  secret, Buf  info, uint16_t  length  )

overridevirtual

Performs HDKF expansion.

Implements fizz::KeyDerivation.

Definition at line 28 of file KeyDerivation-inl.h.

                     {
  return HkdfImpl<Hash>().expand(secret, *info, length);
}

template<typename Hash>

std::vector<uint8_t> fizz::KeyDerivationImpl< Hash >::hkdfExtract ( folly::ByteRange  salt, folly::ByteRange  ikm  )

inlineoverridevirtual

Implements fizz::KeyDerivation.

Definition at line 99 of file KeyDerivation.h.

               {
    return HkdfImpl<Hash>().extract(salt, ikm);
  }

template<typename Hash>

void fizz::KeyDerivationImpl< Hash >::hmac ( folly::ByteRange  key, const folly::IOBuf &  in, folly::MutableByteRange  out  )

inlineoverridevirtual

Implements fizz::KeyDerivation.

Definition at line 74 of file KeyDerivation.h.

                                          {
    Hash::hmac(key, in, out);
  }

Member Data Documentation

template<typename Hash>

std::string fizz::KeyDerivationImpl< Hash >::labelPrefix_

private

Definition at line 105 of file KeyDerivation.h.

Referenced by fizz::KeyDerivationImpl< Hash >::expandLabel().

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The documentation for this class was generated from the following files:

• proxygen/fizz/fizz/crypto/KeyDerivation.h
• proxygen/fizz/fizz/crypto/KeyDerivation-inl.h