Merge bitcoin/bitcoin#27010: refactor: use `Hash` helpers for double-SHA256 calculations

87f11ef47fea31d51bcc3f5df68f78fb28e3d8dd refactor: use `Hash` helper for double-SHA256 calculations (Sebastian Falbesoner)

Pull request description:

  We have two helper templates `Hash(const T& in1)` and `Hash(const T& in1, const T& in2)` available for calculating the double-SHA256 hash of one object or two concatenated objects, respectively:

  https://github.com/bitcoin/bitcoin/blob/b5868f4b1f884e8d6612f34ca4005fe3a992053d/src/hash.h#L74-L89

  This PR uses them in order to increase readability and simplify the code. As in #15294 (which inspired this PR, doing the same for RIPEMD160), the helper is not utilized in validation.cpp and  script/interpreter.cpp to avoid touching consensus-relevant code.

ACKs for top commit:
  john-moffett:
    ACK 87f11ef47fea31d51bcc3f5df68f78fb28e3d8dd
  stickies-v:
    ACK 87f11ef47fea31d51bcc3f5df68f78fb28e3d8dd
  MarcoFalke:
    review ACK 87f11ef47fea31d51bcc3f5df68f78fb28e3d8dd  😬

Tree-SHA512: 11d7e3d00c89685107784010fbffb33ccafb4d1b6a76c4dceb937b29bb234ef4d54581b16bd0737c8d2994a90cf4fe10a9738c7cc5b6d085c6a819f06176dab9

1 files changed, 1 insertions, 2 deletions

diff --git a/src/key.cpp b/src/key.cpp
index 33913ed461..3a3f0b2bc2 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -245,8 +245,7 @@ bool CKey::VerifyPubKey(const CPubKey& pubkey) const {
     unsigned char rnd[8];
     std::string str = "Bitcoin key verification\n";
     GetRandBytes(rnd);
-    uint256 hash;
-    CHash256().Write(MakeUCharSpan(str)).Write(rnd).Finalize(hash);
+    uint256 hash{Hash(str, rnd)};
     std::vector<unsigned char> vchSig;
     Sign(hash, vchSig);
     return pubkey.Verify(hash, vchSig);