addrdb: Only call Serialize() once

The previous logic would call it once for serializing into the filestream,
and then again for serializing into the hasher. If AddrMan was changed
in between these calls by another thread, the resulting peers.dat would
be corrupt with non-matching checksum and data.
Fix this by using HashedSourceWriter, which writes the data
to the underlying stream and keeps track of the hash in one go.

Github-Pull: #26909
Rebased-From: 5eabb61b2386d00e93e6bbb2f493a56d1b326ad9

2 files changed, 4 insertions, 6 deletions

diff --git a/src/addrdb.cpp b/src/addrdb.cpp
index 0fa8f3c3da..0d68719478 100644
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -33,10 +33,9 @@ bool SerializeDB(Stream& stream, const Data& data)
 {
     // Write and commit header, data
     try {
-        CHashWriter hasher(stream.GetType(), stream.GetVersion());
-        stream << Params().MessageStart() << data;
-        hasher << Params().MessageStart() << data;
-        stream << hasher.GetHash();
+        HashedSourceWriter hashwriter{stream};
+        hashwriter << Params().MessageStart() << data;
+        stream << hashwriter.GetHash();
     } catch (const std::exception& e) {
         return error("%s: Serialize or I/O error - %s", __func__, e.what());
     }
diff --git a/src/addrman.cpp b/src/addrman.cpp
index f91a979934..64137e1523 100644
--- a/src/addrman.cpp
+++ b/src/addrman.cpp
@@ -1171,8 +1171,7 @@ void AddrMan::Unserialize(Stream& s_)
 }
 
 // explicit instantiation
-template void AddrMan::Serialize(CHashWriter& s) const;
-template void AddrMan::Serialize(CAutoFile& s) const;
+template void AddrMan::Serialize(HashedSourceWriter<CAutoFile>& s) const;
 template void AddrMan::Serialize(CDataStream& s) const;
 template void AddrMan::Unserialize(CAutoFile& s);
 template void AddrMan::Unserialize(CHashVerifier<CAutoFile>& s);