merge bitcoin#19326: Simplify hash.h interface using Spans

includes:
- 2a2182c387f607cd8284f33890bd285a81077b7f
- 77c507358bda9bd6c496f33e0f4418c0603bb08d

completion of partial merge done in dash#4164 as 56f1b2d (blocker
bitcoin#17938 was merged in dash#5246 as 00802bb)

src/base58.cpp

@@ -136,7 +136,7 @@ std::string EncodeBase58Check(Span<const unsigned char> input)
 {
     // add 4-byte hash check to the end
     std::vector<unsigned char> vch(input.begin(), input.end());
-    uint256 hash = Hash(vch.begin(), vch.end());
+    uint256 hash = Hash(vch);
     vch.insert(vch.end(), (unsigned char*)&hash, (unsigned char*)&hash + 4);
     return EncodeBase58(vch);
 }
@@ -149,7 +149,7 @@ bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet, int
         return false;
     }
     // re-calculate the checksum, ensure it matches the included 4-byte checksum
-    uint256 hash = Hash(vchRet.begin(), vchRet.end() - 4);
+    uint256 hash = Hash(MakeSpan(vchRet).first(vchRet.size() - 4));
     if (memcmp(&hash, &vchRet[vchRet.size() - 4], 4) != 0) {
         vchRet.clear();
         return false;

src/flat-database.h

@@ -47,7 +47,7 @@ private:
         ssObj << strMagicMessage; // specific magic message for this type of object
         ssObj << Params().MessageStart(); // network specific magic number
         ssObj << objToSave;
-        uint256 hash = Hash(ssObj.begin(), ssObj.end());
+        uint256 hash = Hash(ssObj);
         ssObj << hash;
 
         // open output file, and associate with CAutoFile
@@ -109,7 +109,7 @@ private:
         CDataStream ssObj(vchData, SER_DISK, CLIENT_VERSION);
 
         // verify stored checksum matches input data
-        uint256 hashTmp = Hash(ssObj.begin(), ssObj.end());
+        uint256 hashTmp = Hash(ssObj);
         if (hashIn != hashTmp)
         {
             error("%s: Checksum mismatch, data corrupted", __func__);

src/hash.h

@@ -84,52 +84,31 @@ public:
 };
 
 /** Compute the 256-bit hash of an object. */
-template<typename T1>
-inline uint256 Hash(const T1 pbegin, const T1 pend)
+template<typename T>
+inline uint256 Hash(const T& in1)
 {
-    static const unsigned char pblank[1] = {};
     uint256 result;
-    CHash256().Write({pbegin == pend ? pblank : (const unsigned char*)&pbegin[0], (pend - pbegin) * sizeof(pbegin[0])})
-              .Finalize(result);
+    CHash256().Write(MakeUCharSpan(in1)).Finalize(result);
     return result;
 }
 
 /** Compute the 256-bit hash of the concatenation of two objects. */
 template<typename T1, typename T2>
-inline uint256 Hash(const T1 p1begin, const T1 p1end,
-                    const T2 p2begin, const T2 p2end) {
-    static const unsigned char pblank[1] = {};
+inline uint256 Hash(const T1& in1, const T2& in2) {
     uint256 result;
-    CHash256().Write({p1begin == p1end ? pblank : (const unsigned char*)&p1begin[0], (p1end - p1begin) * sizeof(p1begin[0])})
-              .Write({p2begin == p2end ? pblank : (const unsigned char*)&p2begin[0], (p2end - p2begin) * sizeof(p2begin[0])})
-              .Finalize(result);
+    CHash256().Write(MakeUCharSpan(in1)).Write(MakeUCharSpan(in2)).Finalize(result);
     return result;
 }
 
 /** Compute the 160-bit hash an object. */
 template<typename T1>
-inline uint160 Hash160(const T1 pbegin, const T1 pend)
+inline uint160 Hash160(const T1& in1)
 {
-    static unsigned char pblank[1] = {};
     uint160 result;
-    CHash160().Write({pbegin == pend ? pblank : (const unsigned char*)&pbegin[0], (pend - pbegin) * sizeof(pbegin[0])})
-              .Finalize(result);
+    CHash160().Write(MakeUCharSpan(in1)).Finalize(result);
     return result;
 }
 
-/** Compute the 160-bit hash of a vector. */
-inline uint160 Hash160(const std::vector<unsigned char>& vch)
-{
-    return Hash160(vch.begin(), vch.end());
-}
-
-/** Compute the 160-bit hash of a vector. */
-template<unsigned int N>
-inline uint160 Hash160(const prevector<N, unsigned char>& vch)
-{
-    return Hash160(vch.begin(), vch.end());
-}
-
 /** A writer stream (for serialization) that computes a 256-bit hash. */
 class CHashWriter
 {

src/hdchain.cpp

@@ -153,7 +153,7 @@ SecureVector CHDChain::GetSeed() const
 uint256 CHDChain::GetSeedHash()
 {
     LOCK(cs);
-    return Hash(vchSeed.begin(), vchSeed.end());
+    return Hash(vchSeed);
 }
 
 void CHDChain::DeriveChildExtKey(uint32_t nAccountIndex, bool fInternal, uint32_t nChildIndex, CExtKey& extKeyRet, KeyOriginInfo& key_origin)

src/merkleblock.cpp

@@ -84,7 +84,7 @@ uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::ve
         else
             right = left;
         // combine subhashes
-        return Hash(left.begin(), left.end(), right.begin(), right.end());
+        return Hash(left, right);
     }
 }
 
@@ -140,7 +140,7 @@ uint256 CPartialMerkleTree::TraverseAndExtract(int height, unsigned int pos, uns
             right = left;
         }
         // and combine them before returning
-        return Hash(left.begin(), left.end(), right.begin(), right.end());
+        return Hash(left, right);
     }
 }
 

src/net.cpp

@@ -850,7 +850,7 @@ std::optional<CNetMessage> V1TransportDeserializer::GetMessage(int64_t time, uin
 
 void V1TransportSerializer::prepareForTransport(CSerializedNetMsg& msg, std::vector<unsigned char>& header) {
     // create dbl-sha256 checksum
-    uint256 hash = Hash(msg.data.begin(), msg.data.end());
+    uint256 hash = Hash(msg.data);
 
     // create header
     CMessageHeader hdr(Params().MessageStart(), msg.command.c_str(), msg.data.size());

src/netaddress.cpp

@@ -830,7 +830,7 @@ std::vector<unsigned char> CNetAddr::GetAddrBytes() const
 
 uint64_t CNetAddr::GetHash() const
 {
-    uint256 hash = Hash(m_addr.begin(), m_addr.end());
+    uint256 hash = Hash(m_addr);
     uint64_t nRet;
     memcpy(&nRet, &hash, sizeof(nRet));
     return nRet;

src/pubkey.h

@@ -157,13 +157,13 @@ public:
     //! Get the KeyID of this public key (hash of its serialization)
     CKeyID GetID() const
     {
-        return CKeyID(Hash160(vch, vch + size()));
+        return CKeyID(Hash160(MakeSpan(vch).first(size())));
     }
 
     //! Get the 256-bit hash of this public key.
     uint256 GetHash() const
     {
-        return Hash(vch, vch + size());
+        return Hash(MakeSpan(vch).first(size()));
     }
 
     /*

src/script/standard.cpp

@@ -13,10 +13,10 @@ typedef std::vector<unsigned char> valtype;
 bool fAcceptDatacarrier = DEFAULT_ACCEPT_DATACARRIER;
 unsigned nMaxDatacarrierBytes = MAX_OP_RETURN_RELAY;
 
-CScriptID::CScriptID(const CScript& in) : BaseHash(Hash160(in.begin(), in.end())) {}
+CScriptID::CScriptID(const CScript& in) : BaseHash(Hash160(in)) {}
 CScriptID::CScriptID(const ScriptHash& in) : BaseHash(static_cast<uint160>(in)) {}
 
-ScriptHash::ScriptHash(const CScript& in) : BaseHash(Hash160(in.begin(), in.end())) {}
+ScriptHash::ScriptHash(const CScript& in) : BaseHash(Hash160(in)) {}
 ScriptHash::ScriptHash(const CScriptID& in) : BaseHash(static_cast<uint160>(in)) {}
 
 PKHash::PKHash(const CPubKey& pubkey) : BaseHash(pubkey.GetID()) {}
@@ -242,7 +242,6 @@ CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys)
     return script;
 }
 
-
 bool IsValidDestination(const CTxDestination& dest) {
     return dest.index() != 0;
 }

src/test/fuzz/crypto.cpp

@@ -62,8 +62,8 @@ FUZZ_TARGET(crypto)
                 (void)sha512.Write(data.data(), data.size());
                 (void)sip_hasher.Write(data.data(), data.size());
 
+                (void)Hash(data);
                 (void)Hash160(data);
-                (void)Hash160(data.begin(), data.end());
                 (void)sha512.Size();
             },
             [&] {

src/test/fuzz/key.cpp

@@ -81,7 +81,7 @@ FUZZ_TARGET_INIT(key, initialize_key)
         assert(negated_key == key);
     }
 
-    const uint256 random_uint256 = Hash(buffer.begin(), buffer.end());
+    const uint256 random_uint256 = Hash(buffer);
 
     {
         CKey child_key;

src/test/key_tests.cpp

@@ -77,7 +77,7 @@ BOOST_AUTO_TEST_CASE(key_test1)
     for (int n=0; n<16; n++)
     {
         std::string strMsg = strprintf("Very secret message %i: 11", n);
-        uint256 hashMsg = Hash(strMsg.begin(), strMsg.end());
+        uint256 hashMsg = Hash(strMsg);
 
         // normal signatures
 
@@ -134,7 +134,7 @@ BOOST_AUTO_TEST_CASE(key_test1)
 
     std::vector<unsigned char> detsig, detsigc;
     std::string strMsg = "Very deterministic message";
-    uint256 hashMsg = Hash(strMsg.begin(), strMsg.end());
+    uint256 hashMsg = Hash(strMsg);
     BOOST_CHECK(key1.Sign(hashMsg, detsig));
     BOOST_CHECK(key1C.Sign(hashMsg, detsigc));
     BOOST_CHECK(detsig == detsigc);
@@ -158,7 +158,7 @@ BOOST_AUTO_TEST_CASE(key_signature_tests)
     // When entropy is specified, we should see at least one high R signature within 20 signatures
     CKey key = DecodeSecret(strSecret1);
     std::string msg = "A message to be signed";
-    uint256 msg_hash = Hash(msg.begin(), msg.end());
+    uint256 msg_hash = Hash(msg);
     std::vector<unsigned char> sig;
     bool found = false;
 
@@ -179,7 +179,7 @@ BOOST_AUTO_TEST_CASE(key_signature_tests)
     for (int i = 0; i < 256; ++i) {
         sig.clear();
         std::string msg = "A message to be signed" + ToString(i);
-        msg_hash = Hash(msg.begin(), msg.end());
+        msg_hash = Hash(msg);
         BOOST_CHECK(key.Sign(msg_hash, sig));
         found = sig[3] == 0x20;
         BOOST_CHECK(sig.size() <= 70);

src/test/merkle_tests.cpp

@@ -13,9 +13,9 @@ static uint256 ComputeMerkleRootFromBranch(const uint256& leaf, const std::vecto
     uint256 hash = leaf;
     for (std::vector<uint256>::const_iterator it = vMerkleBranch.begin(); it != vMerkleBranch.end(); ++it) {
         if (nIndex & 1) {
-            hash = Hash(it->begin(), it->end(), hash.begin(), hash.end());
+            hash = Hash(*it, hash);
         } else {
-            hash = Hash(hash.begin(), hash.end(), it->begin(), it->end());
+            hash = Hash(hash, *it);
         }
         nIndex >>= 1;
     }
@@ -144,8 +144,7 @@ static uint256 BlockBuildMerkleTree(const CBlock& block, bool* fMutated, std::ve
                 // Two identical hashes at the end of the list at a particular level.
                 mutated = true;
             }
-            vMerkleTree.push_back(Hash(vMerkleTree[j+i].begin(), vMerkleTree[j+i].end(),
-                                       vMerkleTree[j+i2].begin(), vMerkleTree[j+i2].end()));
+            vMerkleTree.push_back(Hash(vMerkleTree[j+i], vMerkleTree[j+i2]));
         }
         j += nSize;
     }

src/test/serialize_tests.cpp

@@ -145,7 +145,7 @@ BOOST_AUTO_TEST_CASE(floats)
     for (int i = 0; i < 1000; i++) {
         ss << float(i);
     }
-    BOOST_CHECK(Hash(ss.begin(), ss.end()) == uint256S("8e8b4cf3e4df8b332057e3e23af42ebc663b61e0495d5e7e32d85099d7f3fe0c"));
+    BOOST_CHECK(Hash(ss) == uint256S("8e8b4cf3e4df8b332057e3e23af42ebc663b61e0495d5e7e32d85099d7f3fe0c"));
 
     // decode
     for (int i = 0; i < 1000; i++) {
@@ -162,7 +162,7 @@ BOOST_AUTO_TEST_CASE(doubles)
     for (int i = 0; i < 1000; i++) {
         ss << double(i);
     }
-    BOOST_CHECK(Hash(ss.begin(), ss.end()) == uint256S("43d0c82591953c4eafe114590d392676a01585d25b25d433557f0d7878b23f96"));
+    BOOST_CHECK(Hash(ss) == uint256S("43d0c82591953c4eafe114590d392676a01585d25b25d433557f0d7878b23f96"));
 
     // decode
     for (int i = 0; i < 1000; i++) {

src/test/util_tests.cpp

@@ -2576,8 +2576,8 @@ BOOST_AUTO_TEST_CASE(message_hash)
         std::string(1, (char)unsigned_tx.length()) +
         unsigned_tx;
 
-    const uint256 signature_hash = Hash(unsigned_tx.begin(), unsigned_tx.end());
-    const uint256 message_hash1 = Hash(prefixed_message.begin(), prefixed_message.end());
+    const uint256 signature_hash = Hash(unsigned_tx);
+    const uint256 message_hash1 = Hash(prefixed_message);
     const uint256 message_hash2 = MessageHash(unsigned_tx);
 
     BOOST_CHECK_EQUAL(message_hash1, message_hash2);

src/util/hash_type.h

@@ -64,6 +64,9 @@ public:
     {
         return m_hash.size();
     }
+
+    unsigned char* data() { return m_hash.data(); }
+    const unsigned char* data() const { return m_hash.data(); }
 };
 
 #endif // BITCOIN_UTIL_HASH_TYPE_H

src/wallet/test/wallet_tests.cpp

@@ -1323,7 +1323,7 @@ static size_t CalculateNestedKeyhashInputSize(bool use_max_sig)
     CPubKey pubkey = key.GetPubKey();
 
     // Generate pubkey hash
-    uint160 key_hash(Hash160(pubkey.begin(), pubkey.end()));
+    uint160 key_hash(Hash160(pubkey));
 
     // Create inner-script to enter into keystore. Key hash can't be 0...
     CScript inner_script = CScript() << OP_0 << std::vector<unsigned char>(key_hash.begin(), key_hash.end());

src/wallet/walletdb.cpp

@@ -113,7 +113,7 @@ bool WalletBatch::WriteKey(const CPubKey& vchPubKey, const CPrivKey& vchPrivKey,
     vchKey.insert(vchKey.end(), vchPubKey.begin(), vchPubKey.end());
     vchKey.insert(vchKey.end(), vchPrivKey.begin(), vchPrivKey.end());
 
-    return WriteIC(std::make_pair(DBKeys::KEY, vchPubKey), std::make_pair(vchPrivKey, Hash(vchKey.begin(), vchKey.end())), false);
+    return WriteIC(std::make_pair(DBKeys::KEY, vchPubKey), std::make_pair(vchPrivKey, Hash(vchKey)), false);
 }
 
 bool WalletBatch::WriteCryptedKey(const CPubKey& vchPubKey,
@@ -125,7 +125,7 @@ bool WalletBatch::WriteCryptedKey(const CPubKey& vchPubKey,
     }
 
     // Compute a checksum of the encrypted key
-    uint256 checksum = Hash(vchCryptedSecret.begin(), vchCryptedSecret.end());
+    uint256 checksum = Hash(vchCryptedSecret);
 
     const auto key = std::make_pair(DBKeys::CRYPTED_KEY, vchPubKey);
     if (!WriteIC(key, std::make_pair(vchCryptedSecret, checksum), false)) {
@@ -339,7 +339,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
                 vchKey.insert(vchKey.end(), vchPubKey.begin(), vchPubKey.end());
                 vchKey.insert(vchKey.end(), pkey.begin(), pkey.end());
 
-                if (Hash(vchKey.begin(), vchKey.end()) != hash)
+                if (Hash(vchKey) != hash)
                 {
                     strErr = "Error reading wallet database: CPubKey/CPrivKey corrupt";
                     return false;
@@ -388,7 +388,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             if (!ssValue.eof()) {
                 uint256 checksum;
                 ssValue >> checksum;
-                if ((checksum_valid = Hash(vchPrivKey.begin(), vchPrivKey.end()) != checksum)) {
+                if ((checksum_valid = Hash(vchPrivKey) != checksum)) {
                     strErr = "Error reading wallet database: Crypted key corrupt";
                     return false;
                 }