Support for Testnet4

[claytantor]

TestNet4 is coming and it would be awesome if there was an easy way to configure Network.TestNet to use testnet3, testnet4, or whatever.

I see something like Network.GetNetwork("testnet3") in some tests, is it possible to self configure for "testnet4"

in the implementation of Network.TestNet I see the following:

_TestNet = new Network("TestNet",
                Encoders.Hex.DecodeData("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"),
                0x0709110B,
                null,
                NBitcoin.Bitcoin.Instance);

If I got some pointers/breadcrumbs on the appropriate encoding values for testnet4 I could probably implement it in a branch...

https://github.com/bitcoin/bitcoin/pull/29775

[jlopp]

Here's the raw hex of the (current) testnet4 genesis block; it's subject to change until such time as the PR is merged though hopefully it won't.

0100000000000000000000000000000000000000000000000000000000000000000000004e7b2b9128fe0291db0693af2ae418b767e657cd407e80cb1434221eaea7a07a046f3566ffff001dbb0c78170101000000010000000000000000000000000000000000000000000000000000000000000000ffffffff5504ffff001d01044c4c30332f4d61792f323032342030303030303030303030303030303030303030303165626435386332343439373062336161396437383362623030313031316662653865613865393865303065ffffffff0100f2052a010000002321000000000000000000000000000000000000000000000000000000000000000000ac00000000

[claytantor]

Do you have any idea what 0x0709110B represents? Seems like its the magic number? Do we know the magic number for testnet4 ?

https://www.anintegratedworld.com/unravelling-the-mysterious-block-chain-magic-number/

[jlopp]

Looks like the network magic.

In the Bitcoin Core PR it's not very well commented; netmagic in chainparams.cpp is "pchMessageStart" which means the netmagic for testnet4 is 0x1c163f28.

Though note how testnet3 is defined in kernel/chainparams.cpp:

        pchMessageStart[0] = 0x0b;
        pchMessageStart[1] = 0x11;
        pchMessageStart[2] = 0x09;
        pchMessageStart[3] = 0x07;

Which is 0x0b110907 compared to NBitcoin's 0x0709110B.

This leads me to believe that Bitcoin Core and NBitcoin are using different endian notations. So the NBitcoin network magic string for testnet4 should be 0x283F161C

[claytantor]

This leads me to believe that Bitcoin Core and NBitcoin are using different endian notations. So the NBitcoin network magic string for testnet4 should be 0x283F161C

Sooper helpful. PR incoming.

[mathis1337]

Just curious if there was any progress on this?

[turbolay]

I made a PR for that, #1216, but I'm not sure what to use as vSeeds for TestNet4