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Avoid introducing a virtual into CChainParams
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Treat fSkipProofOfWorkCheck the same as other parameters.
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@laanwj
laanwj committed Sep 29, 2014
1 parent 5e2e7fc commit 4705902
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Showing 2 changed files with 3 additions and 5 deletions.
5 changes: 1 addition & 4 deletions src/chainparams.cpp
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Expand Up @@ -115,6 +115,7 @@ class CMainParams : public CChainParams {
fAllowMinDifficultyBlocks = false;
fRequireStandard = true;
fMineBlocksOnDemand = false;
fSkipProofOfWorkCheck = false;
}
};
static CMainParams mainParams;
Expand Down Expand Up @@ -231,11 +232,7 @@ class CUnitTestParams : public CMainParams, public CModifiableParams {
fDefaultCheckMemPool = true;
fAllowMinDifficultyBlocks = false;
fMineBlocksOnDemand = true;
fSkipProofOfWorkCheck = false;
}
virtual bool SkipProofOfWorkCheck() const { return fSkipProofOfWorkCheck; }
protected:
bool fSkipProofOfWorkCheck;
public:
// Published setters to allow changing values in unit test cases
virtual void setSubsidyHalvingInterval(int anSubsidyHalvingInterval) { nSubsidyHalvingInterval=anSubsidyHalvingInterval; }
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3 changes: 2 additions & 1 deletion src/chainparams.h
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Expand Up @@ -62,7 +62,7 @@ class CChainParams
/* Allow mining of a min-difficulty block */
bool AllowMinDifficultyBlocks() const { return fAllowMinDifficultyBlocks; }
/* Skip proof-of-work check: allow mining of any difficulty block */
virtual bool SkipProofOfWorkCheck() const { return false; }
bool SkipProofOfWorkCheck() const { return fSkipProofOfWorkCheck; }
/* Make standard checks */
bool RequireStandard() const { return fRequireStandard; }
int64_t TargetTimespan() const { return nTargetTimespan; }
Expand Down Expand Up @@ -105,6 +105,7 @@ class CChainParams
bool fAllowMinDifficultyBlocks;
bool fRequireStandard;
bool fMineBlocksOnDemand;
bool fSkipProofOfWorkCheck;
};

/** Modifiable parameters interface is used by test cases to adapt the parameters in order
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4 comments on commit 4705902

@SergioDemianLerner
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Ok. But the reason I did write the virtual function returning false was to prevent any possibility of the flag being turned on on the MAIN network by mistake. This was requested by (I think) GMaxwell.
It was a protective measure...

@laanwj
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@laanwj laanwj commented on 4705902 Sep 29, 2014

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Corrupting any of the other parameters will have bad consequences as well.

@SergioDemianLerner
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Yes, I agree. There are plenty of global variables an attacker could corrupt if he has access to write arbitrary bytes in process memory. So remove it if you wish...

@laanwj
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@laanwj laanwj commented on 4705902 Sep 29, 2014

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Virtual pointers also provide a single place that can be overwritten to make the object point to a different class. It's a bit more difficult as you have to know what address to write, but still no rocket science...

The most extreme form of making these parameters static would be to provide the chain parameters to a template class implementing the consensus code, then compile/instantiate that for each network separately. Then at start-up, load only the code for the network that is selected.

Then again -- it may be pointless, I don't think there is any realistic protection against attackers that already have write access to your memory space.

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