partial Merge bitcoin#17212: refactor: Remove unused CExt{Pub,}Key (de)serialization methods

5b44a75 refactor: Remove unused CExt{Pub,}Key (de)serialization methods (Sebastian Falbesoner)

Pull request description:

  As pointed out in issue bitcoin#17130, the serialization/deserialization methods for the classes `CExtKey` and
  `CExtPubKey` are only used in the BIP32 unit tests and hence can be removed (see comments bitcoin#17130 (comment), bitcoin#17130 (comment) and bitcoin#17130 (comment)).

ACKs for top commit:
  practicalswift:
    ACK 5b44a75 -- -60 LOC diff looks correct :)
  promag:
    ACK 5b44a75.
  MarcoFalke:
    unsigned ACK 5b44a75
  fjahr:
    ACK 5b44a75
  jonatack:
    Light ACK 5b44a75. Built, ran tests and bitcoind. `git blame` shows most of the last changes are from commit 90604f1 in 2015 to add bip32 pubkey serialization.

Tree-SHA512: 6887573b76b9e54e117a076557407b6f7908719b2202fb9eea498522baf9f30198b3f78b87a62efcd17ad1ab0886196f099239992ce7cbbaee79979ffe9e5f2c

Author: MarcoFalke

src/key.h

@@ -161,25 +161,6 @@ struct CExtKey {
     bool Derive(CExtKey& out, unsigned int nChild) const;
     CExtPubKey Neuter() const;
     void SetSeed(const unsigned char* seed, unsigned int nSeedLen);
-    template <typename Stream>
-    void Serialize(Stream& s) const
-    {
-        unsigned int len = BIP32_EXTKEY_SIZE;
-        ::WriteCompactSize(s, len);
-        unsigned char code[BIP32_EXTKEY_SIZE];
-        Encode(code);
-        s.write((const char *)&code[0], len);
-    }
-    template <typename Stream>
-    void Unserialize(Stream& s)
-    {
-        unsigned int len = ::ReadCompactSize(s);
-        unsigned char code[BIP32_EXTKEY_SIZE];
-        if (len != BIP32_EXTKEY_SIZE)
-            throw std::runtime_error("Invalid extended key size\n");
-        s.read((char *)&code[0], len);
-        Decode(code);
-    }
 };
 
 /** Initialize the elliptic curve support. May not be called twice without calling ECC_Stop first. */

src/test/bip32_tests.cpp

@@ -118,22 +118,6 @@ static void RunTest(const TestVector &test) {
         }
         key = keyNew;
         pubkey = pubkeyNew;
-
-        CDataStream ssPub(SER_DISK, CLIENT_VERSION);
-        ssPub << pubkeyNew;
-        BOOST_CHECK(ssPub.size() == 75);
-
-        CDataStream ssPriv(SER_DISK, CLIENT_VERSION);
-        ssPriv << keyNew;
-        BOOST_CHECK(ssPriv.size() == 75);
-
-        CExtPubKey pubCheck;
-        CExtKey privCheck;
-        ssPub >> pubCheck;
-        ssPriv >> privCheck;
-
-        BOOST_CHECK(pubCheck == pubkeyNew);
-        BOOST_CHECK(privCheck == keyNew);
     }
 }