Move makeKeyDerivation, makeHandshakeContext into base Factory implem…

…entation

Summary:
Now that the Factory has a pure virtual `makeHasherFactory()` primitive,
`KeyDerivation` and `HandshakeContext` can be expressed in terms of this
primitive.

Reviewed By: zalecodez

Differential Revision: D63283091

fbshipit-source-id: 574edb27d1496ff02c266d144cb3813a524e680e

fizz/protocol/Factory.cpp

@@ -53,6 +53,19 @@ std::unique_ptr<folly::IOBuf> Factory::makeRandomBytes(size_t count) const {
   return RandomBufGenerator(count).generateRandom();
 }
 
+std::unique_ptr<HandshakeContext> Factory::makeHandshakeContext(
+    CipherSuite cipher) const {
+  auto hasherFactory = makeHasherFactory(getHashFunction(cipher));
+  return std::make_unique<HandshakeContextImpl>(hasherFactory);
+}
+//
+
+std::unique_ptr<KeyDerivation> Factory::makeKeyDeriver(
+    CipherSuite cipher) const {
+  auto hasher = makeHasherFactory(getHashFunction(cipher));
+  return std::make_unique<KeyDerivationImpl>(hasher);
+}
+
 std::shared_ptr<Cert> Factory::makeIdentityOnlyCert(std::string ident) const {
   return std::make_shared<IdentityCert>(std::move(ident));
 }

fizz/protocol/Factory.h

@@ -74,10 +74,10 @@ class Factory {
       CipherSuite cipher) const;
 
   virtual std::unique_ptr<KeyDerivation> makeKeyDeriver(
-      CipherSuite cipher) const = 0;
+      CipherSuite cipher) const;
 
   virtual std::unique_ptr<HandshakeContext> makeHandshakeContext(
-      CipherSuite cipher) const = 0;
+      CipherSuite cipher) const;
 
   virtual std::unique_ptr<KeyExchange> makeKeyExchange(
       NamedGroup group,

fizz/protocol/MultiBackendFactory.cpp

@@ -84,13 +84,6 @@ std::unique_ptr<Aead> MultiBackendFactory::makeAead(CipherSuite cipher) const {
   }
 }
 
-// TODO: This belongs in Factory
-std::unique_ptr<KeyDerivation> MultiBackendFactory::makeKeyDeriver(
-    CipherSuite cipher) const {
-  auto hasher = makeHasherFactory(getHashFunction(cipher));
-  return std::make_unique<KeyDerivationImpl>(hasher);
-}
-
 const HasherFactoryWithMetadata* MultiBackendFactory::makeHasherFactory(
     HashFunction digest) const {
   switch (digest) {
@@ -105,13 +98,6 @@ const HasherFactoryWithMetadata* MultiBackendFactory::makeHasherFactory(
   }
 }
 
-// TODO: This belongs in Factory
-std::unique_ptr<HandshakeContext> MultiBackendFactory::makeHandshakeContext(
-    CipherSuite cipher) const {
-  auto hasherFactory = makeHasherFactory(getHashFunction(cipher));
-  return std::make_unique<HandshakeContextImpl>(hasherFactory);
-}
-
 std::unique_ptr<PeerCert> MultiBackendFactory::makePeerCert(
     CertificateEntry certEntry,
     bool /*leaf*/) const {

fizz/protocol/MultiBackendFactory.h

@@ -30,15 +30,9 @@ class MultiBackendFactory : public Factory {
   [[nodiscard]] std::unique_ptr<Aead> makeAead(
       CipherSuite cipher) const override;
 
-  std::unique_ptr<KeyDerivation> makeKeyDeriver(
-      CipherSuite cipher) const override;
-
   const HasherFactoryWithMetadata* makeHasherFactory(
       HashFunction digest) const override;
 
-  std::unique_ptr<HandshakeContext> makeHandshakeContext(
-      CipherSuite cipher) const override;
-
   [[nodiscard]] std::unique_ptr<PeerCert> makePeerCert(
       CertificateEntry certEntry,
       bool /*leaf*/) const override;