extract sporkmanager from sporkmessage (#2234)

The SporkMessage is a lower-level construct which shouldn't be aware of
SporkManager. This commit moves the `sporkManager.IsSporkActive()` calls
outside the SporkMessage functions. This follows the dependency injection
pattern and makes it easier to test SporkMessage as well.

src/spork.cpp

@@ -68,7 +68,7 @@ void CSporkManager::ProcessSpork(CNode* pfrom, const std::string& strCommand, CD
             }
         }
 
-        if(!spork.CheckSignature(sporkPubKeyID)) {
+        if(!spork.CheckSignature(sporkPubKeyID, IsSporkActive(SPORK_6_NEW_SIGS))) {
             LOCK(cs_main);
             LogPrintf("CSporkManager::ProcessSpork -- ERROR: invalid signature\n");
             Misbehaving(pfrom->GetId(), 100);
@@ -127,7 +127,7 @@ bool CSporkManager::UpdateSpork(int nSporkID, int64_t nValue, CConnman& connman)
 {
     CSporkMessage spork = CSporkMessage(nSporkID, nValue, GetAdjustedTime());
 
-    if(spork.Sign(sporkPrivKey)) {
+    if(spork.Sign(sporkPrivKey, IsSporkActive(SPORK_6_NEW_SIGS))) {
         spork.Relay(connman);
         LOCK(cs);
         mapSporksByHash[spork.GetHash()] = spork;
@@ -244,7 +244,7 @@ bool CSporkManager::SetPrivKey(const std::string& strPrivKey)
     }
 
     CSporkMessage spork;
-    if (spork.Sign(key)) {
+    if (spork.Sign(key, IsSporkActive(SPORK_6_NEW_SIGS))) {
 	    LOCK(cs);
         // Test signing successful, proceed
         LogPrintf("CSporkManager::SetPrivKey -- Successfully initialized as spork signer\n");
@@ -274,7 +274,7 @@ uint256 CSporkMessage::GetSignatureHash() const
     return GetHash();
 }
 
-bool CSporkMessage::Sign(const CKey& key)
+bool CSporkMessage::Sign(const CKey& key, bool fSporkSixActive)
 {
     if (!key.IsValid()) {
         LogPrintf("CSporkMessage::Sign -- signing key is not valid\n");
@@ -284,7 +284,7 @@ bool CSporkMessage::Sign(const CKey& key)
     CKeyID pubKeyId = key.GetPubKey().GetID();
     std::string strError = "";
 
-    if (sporkManager.IsSporkActive(SPORK_6_NEW_SIGS)) {
+    if (fSporkSixActive) {
         uint256 hash = GetSignatureHash();
 
         if(!CHashSigner::SignHash(hash, key, vchSig)) {
@@ -313,11 +313,11 @@ bool CSporkMessage::Sign(const CKey& key)
     return true;
 }
 
-bool CSporkMessage::CheckSignature(const CKeyID& pubKeyId) const
+bool CSporkMessage::CheckSignature(const CKeyID& pubKeyId, bool fSporkSixActive) const
 {
     std::string strError = "";
 
-    if (sporkManager.IsSporkActive(SPORK_6_NEW_SIGS)) {
+    if (fSporkSixActive) {
         uint256 hash = GetSignatureHash();
 
         if (!CHashSigner::VerifyHash(hash, pubKeyId, vchSig, strError)) {

src/spork.h

@@ -76,8 +76,8 @@ class CSporkMessage
     uint256 GetHash() const;
     uint256 GetSignatureHash() const;
 
-    bool Sign(const CKey& key);
-    bool CheckSignature(const CKeyID& pubKeyId) const;
+    bool Sign(const CKey& key, bool fSporkSixActive);
+    bool CheckSignature(const CKeyID& pubKeyId, bool fSporkSixActive) const;
     void Relay(CConnman& connman);
 };