Update embedded asmap to 1788801420 #36201

1. 
   fjahr commented at 8:41 AM on September 9, 2026: contributor

   Depends on #36199 and https://github.com/bitcoin-core/asmap-data/pull/70 getting merged and receiving enough attestations. The run just happened so I hope we'll get these ACKs before the end of the week.

2. 
   DrahtBot commented at 8:41 AM on September 9, 2026: contributor

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   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/36201.

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3. fanquake added this to the milestone 32.0 on Sep 9, 2026
4. 
   fanquake commented at 2:25 PM on September 9, 2026: member

   Can you rebase / undraft?

5. net: Update embedded asmap to 1788801420 3c91db262b
6. fjahr force-pushed on Sep 9, 2026
7. fjahr marked this as ready for review on Sep 9, 2026
8. 
   fanquake commented at 2:32 PM on September 9, 2026: member

   cc @hodlinator @jurraca

9. 
   jurraca commented at 4:17 PM on September 9, 2026: contributor

   The correct ASmap loads: I can recover it via the exportasmap RPC and validate the hash.

   However, I see a different hash in the logs:

   Using asmap version cf4902a32e355ec3effcde94f6605766378a01666918f3044b063358c96b6f6d for IP bucketing
   

   Given the AsmapVersion function, is that intended?

10. hodlinator approved
11. 
    hodlinator commented at 6:08 PM on September 9, 2026: contributor

    ACK 3c91db262b74f001a30bc5834daf322eadc19c46

    Verified the hash of src/node/data/ip_asn.dat matches what I ACKed in https://github.com/bitcoin-core/asmap-data/pull/70.

    re #36201 (comment):

    However, I see a different hash in the logs:

    Using asmap version cf4902a32e355ec3effcde94f6605766378a01666918f3044b063358c96b6f6d for IP bucketing
    

    That comes from bitcoind outputting the double-SHA256 hash. I put the 03580ade8ec0036ad3d6a5a91602b995c89387f722d3fee58127219de6aafc12 hash into https://emn178.github.io/online-tools/sha256.html in hex-input mode and it returned the hash above, only in inverse byte order.

    It would be nice to switch bitcoind to output the single-SHA256 hash instead, maybe in a follow-up PR:

    --- a/src/util/asmap.cpp
    +++ b/src/util/asmap.cpp
    @@ -349,5 +349,5 @@ uint256 AsmapVersion(const std::span<const std::byte> data)
     
         HashWriter asmap_hasher;
         asmap_hasher << data;
    -    return asmap_hasher.GetHash();
    +    return asmap_hasher.GetSHA256();
     }
    

    Unfortunately the outputted hash is still in reverse byte order. Wonder if we should have a distinct uint256-type for regular order.

12. 
    jurraca commented at 8:40 PM on September 9, 2026: contributor

    ah thanks, I tried a few things but forgot the hash is reversed. Agreed on dropping the double hash.

13. jurraca approved
14. 
    hodlinator commented at 9:52 AM on September 10, 2026: contributor

    Attempt to improve bitcoind log output so the hash can be grepped is now up for review in #36215.

15. fanquake merged this on Sep 10, 2026
16. fanquake closed this on Sep 10, 2026

    ---

17. 
    fanquake commented at 10:10 AM on September 10, 2026: member

    Backported to 31.x in #35969.

18. fanquake referenced this in commit dfcaeb0de2 on Sep 10, 2026

Milestone
32.0