Make DecodeBase{32,64} always return vector, not string

Base32/base64 are mechanisms for encoding binary data. That they'd
decode to a string is just bizarre. The fact that they'd do that
based on the type of input arguments even more so.

13 files changed, 31 insertions, 30 deletions

diff --git a/src/httprpc.cpp b/src/httprpc.cpp
index 5d62568343..96cccd8de9 100644
--- a/src/httprpc.cpp
+++ b/src/httprpc.cpp
@@ -133,8 +133,9 @@ static bool RPCAuthorized(const std::string& strAuth, std::string& strAuthUserna
         return false;
     std::string strUserPass64 = TrimString(strAuth.substr(6));
     bool invalid;
-    std::string strUserPass = DecodeBase64(strUserPass64, &invalid);
+    std::vector<unsigned char> userpass_data = DecodeBase64(strUserPass64, &invalid);
     if (invalid) return false;
+    std::string strUserPass(userpass_data.begin(), userpass_data.end());
 
     if (strUserPass.find(':') != std::string::npos)
         strAuthUsernameOut = strUserPass.substr(0, strUserPass.find(':'));
diff --git a/src/i2p.cpp b/src/i2p.cpp
index ccba14d63d..66f19b90d0 100644
--- a/src/i2p.cpp
+++ b/src/i2p.cpp
@@ -70,7 +70,7 @@ static Binary DecodeI2PBase64(const std::string& i2p_b64)
 {
     const std::string& std_b64 = SwapBase64(i2p_b64);
     bool invalid;
-    Binary decoded = DecodeBase64(std_b64.c_str(), &invalid);
+    Binary decoded = DecodeBase64(std_b64, &invalid);
     if (invalid) {
         throw std::runtime_error(strprintf("Cannot decode Base64: \"%s\"", i2p_b64));
     }
diff --git a/src/netaddress.cpp b/src/netaddress.cpp
index bc1915aad9..18f56c9bbe 100644
--- a/src/netaddress.cpp
+++ b/src/netaddress.cpp
@@ -235,7 +235,7 @@ bool CNetAddr::SetTor(const std::string& addr)
     }
 
     bool invalid;
-    const auto& input = DecodeBase32(addr.substr(0, addr.size() - suffix_len).c_str(), &invalid);
+    const auto& input = DecodeBase32(addr.substr(0, addr.size() - suffix_len), &invalid);
 
     if (invalid) {
         return false;
diff --git a/src/psbt.cpp b/src/psbt.cpp
index c8c73e130b..9b8f909349 100644
--- a/src/psbt.cpp
+++ b/src/psbt.cpp
@@ -389,17 +389,17 @@ std::string PSBTRoleName(PSBTRole role) {
 bool DecodeBase64PSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error)
 {
     bool invalid;
-    std::string tx_data = DecodeBase64(base64_tx, &invalid);
+    auto tx_data = DecodeBase64(base64_tx, &invalid);
     if (invalid) {
         error = "invalid base64";
         return false;
     }
-    return DecodeRawPSBT(psbt, tx_data, error);
+    return DecodeRawPSBT(psbt, MakeByteSpan(tx_data), error);
 }
 
-bool DecodeRawPSBT(PartiallySignedTransaction& psbt, const std::string& tx_data, std::string& error)
+bool DecodeRawPSBT(PartiallySignedTransaction& psbt, Span<const std::byte> tx_data, std::string& error)
 {
-    CDataStream ss_data(MakeByteSpan(tx_data), SER_NETWORK, PROTOCOL_VERSION);
+    CDataStream ss_data(tx_data, SER_NETWORK, PROTOCOL_VERSION);
     try {
         ss_data >> psbt;
         if (!ss_data.empty()) {
diff --git a/src/psbt.h b/src/psbt.h
index f0ceb02481..8a9cbd33d2 100644
--- a/src/psbt.h
+++ b/src/psbt.h
@@ -988,6 +988,6 @@ bool FinalizeAndExtractPSBT(PartiallySignedTransaction& psbtx, CMutableTransacti
 //! Decode a base64ed PSBT into a PartiallySignedTransaction
 [[nodiscard]] bool DecodeBase64PSBT(PartiallySignedTransaction& decoded_psbt, const std::string& base64_psbt, std::string& error);
 //! Decode a raw (binary blob) PSBT into a PartiallySignedTransaction
-[[nodiscard]] bool DecodeRawPSBT(PartiallySignedTransaction& decoded_psbt, const std::string& raw_psbt, std::string& error);
+[[nodiscard]] bool DecodeRawPSBT(PartiallySignedTransaction& decoded_psbt, Span<const std::byte> raw_psbt, std::string& error);
 
 #endif // BITCOIN_PSBT_H
diff --git a/src/qt/walletframe.cpp b/src/qt/walletframe.cpp
index 91ce420a33..663e86aa29 100644
--- a/src/qt/walletframe.cpp
+++ b/src/qt/walletframe.cpp
@@ -194,7 +194,7 @@ void WalletFrame::gotoVerifyMessageTab(QString addr)
 
 void WalletFrame::gotoLoadPSBT(bool from_clipboard)
 {
-    std::string data;
+    std::vector<unsigned char> data;
 
     if (from_clipboard) {
         std::string raw = QApplication::clipboard()->text().toStdString();
@@ -214,12 +214,12 @@ void WalletFrame::gotoLoadPSBT(bool from_clipboard)
             return;
         }
         std::ifstream in{filename.toLocal8Bit().data(), std::ios::binary};
-        data = std::string(std::istreambuf_iterator<char>{in}, {});
+        data.assign(std::istream_iterator<unsigned char>{in}, {});
     }
 
     std::string error;
     PartiallySignedTransaction psbtx;
-    if (!DecodeRawPSBT(psbtx, data, error)) {
+    if (!DecodeRawPSBT(psbtx, MakeByteSpan(data), error)) {
         Q_EMIT message(tr("Error"), tr("Unable to decode PSBT") + "\n" + QString::fromStdString(error), CClientUIInterface::MSG_ERROR);
         return;
     }
diff --git a/src/test/base32_tests.cpp b/src/test/base32_tests.cpp
index 8a44e65165..2e5f6a2378 100644
--- a/src/test/base32_tests.cpp
+++ b/src/test/base32_tests.cpp
@@ -23,9 +23,9 @@ BOOST_AUTO_TEST_CASE(base32_testvectors)
         strEnc = EncodeBase32(vstrIn[i], false);
         BOOST_CHECK_EQUAL(strEnc, vstrOutNoPadding[i]);
         bool invalid;
-        std::string strDec = DecodeBase32(vstrOut[i], &invalid);
+        auto dec = DecodeBase32(vstrOut[i], &invalid);
         BOOST_CHECK(!invalid);
-        BOOST_CHECK_EQUAL(strDec, vstrIn[i]);
+        BOOST_CHECK_MESSAGE(MakeByteSpan(dec) == MakeByteSpan(vstrIn[i]), vstrOut[i]);
     }
 
     // Decoding strings with embedded NUL characters should fail
diff --git a/src/test/base64_tests.cpp b/src/test/base64_tests.cpp
index 04b5185653..5727b09838 100644
--- a/src/test/base64_tests.cpp
+++ b/src/test/base64_tests.cpp
@@ -20,9 +20,9 @@ BOOST_AUTO_TEST_CASE(base64_testvectors)
         std::string strEnc = EncodeBase64(vstrIn[i]);
         BOOST_CHECK_EQUAL(strEnc, vstrOut[i]);
         bool invalid;
-        std::string strDec = DecodeBase64(strEnc, &invalid);
+        auto dec = DecodeBase64(strEnc, &invalid);
         BOOST_CHECK(!invalid);
-        BOOST_CHECK_EQUAL(strDec, vstrIn[i]);
+        BOOST_CHECK_MESSAGE(MakeByteSpan(dec) == MakeByteSpan(vstrIn[i]), vstrOut[i]);
     }
 
     {
diff --git a/src/test/fuzz/base_encode_decode.cpp b/src/test/fuzz/base_encode_decode.cpp
index 196410e29c..0d48a140f7 100644
--- a/src/test/fuzz/base_encode_decode.cpp
+++ b/src/test/fuzz/base_encode_decode.cpp
@@ -37,16 +37,16 @@ FUZZ_TARGET_INIT(base_encode_decode, initialize_base_encode_decode)
     }
 
     bool pf_invalid;
-    std::string decoded_string = DecodeBase32(random_encoded_string, &pf_invalid);
+    decoded = DecodeBase32(random_encoded_string, &pf_invalid);
     if (!pf_invalid) {
-        const std::string encoded_string = EncodeBase32(decoded_string);
+        const std::string encoded_string = EncodeBase32(decoded);
         assert(encoded_string == TrimString(encoded_string));
         assert(ToLower(encoded_string) == ToLower(TrimString(random_encoded_string)));
     }
 
-    decoded_string = DecodeBase64(random_encoded_string, &pf_invalid);
+    decoded = DecodeBase64(random_encoded_string, &pf_invalid);
     if (!pf_invalid) {
-        const std::string encoded_string = EncodeBase64(decoded_string);
+        const std::string encoded_string = EncodeBase64(decoded);
         assert(encoded_string == TrimString(encoded_string));
         assert(ToLower(encoded_string) == ToLower(TrimString(random_encoded_string)));
     }
diff --git a/src/test/fuzz/psbt.cpp b/src/test/fuzz/psbt.cpp
index 669688a80d..baa64bba0f 100644
--- a/src/test/fuzz/psbt.cpp
+++ b/src/test/fuzz/psbt.cpp
@@ -32,7 +32,8 @@ FUZZ_TARGET_INIT(psbt, initialize_psbt)
     FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
     PartiallySignedTransaction psbt_mut;
     std::string error;
-    if (!DecodeRawPSBT(psbt_mut, fuzzed_data_provider.ConsumeRandomLengthString(), error)) {
+    auto str = fuzzed_data_provider.ConsumeRandomLengthString();
+    if (!DecodeRawPSBT(psbt_mut, MakeByteSpan(str), error)) {
         return;
     }
     const PartiallySignedTransaction psbt = psbt_mut;
@@ -79,7 +80,8 @@ FUZZ_TARGET_INIT(psbt, initialize_psbt)
     }
 
     PartiallySignedTransaction psbt_merge;
-    if (!DecodeRawPSBT(psbt_merge, fuzzed_data_provider.ConsumeRandomLengthString(), error)) {
+    str = fuzzed_data_provider.ConsumeRandomLengthString();
+    if (!DecodeRawPSBT(psbt_merge, MakeByteSpan(str), error)) {
         psbt_merge = psbt;
     }
     psbt_mut = psbt;
diff --git a/src/util/message.cpp b/src/util/message.cpp
index 2c7f0406f0..a4e495c1d1 100644
--- a/src/util/message.cpp
+++ b/src/util/message.cpp
@@ -36,7 +36,7 @@ MessageVerificationResult MessageVerify(
     }
 
     bool invalid = false;
-    std::vector<unsigned char> signature_bytes = DecodeBase64(signature.c_str(), &invalid);
+    std::vector<unsigned char> signature_bytes = DecodeBase64(signature, &invalid);
     if (invalid) {
         return MessageVerificationResult::ERR_MALFORMED_SIGNATURE;
     }
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
index 6b6644aa9f..a861885269 100644
--- a/src/util/strencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -172,14 +172,13 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid)
     return ret;
 }
 
-std::string DecodeBase64(const std::string& str, bool* pf_invalid)
+std::vector<unsigned char> DecodeBase64(const std::string& str, bool* pf_invalid)
 {
     if (!ValidAsCString(str)) {
         *pf_invalid = true;
         return {};
     }
-    std::vector<unsigned char> vchRet = DecodeBase64(str.c_str(), pf_invalid);
-    return std::string((const char*)vchRet.data(), vchRet.size());
+    return DecodeBase64(str.c_str(), pf_invalid);
 }
 
 std::string EncodeBase32(Span<const unsigned char> input, bool pad)
@@ -248,14 +247,13 @@ std::vector<unsigned char> DecodeBase32(const char* p, bool* pf_invalid)
     return ret;
 }
 
-std::string DecodeBase32(const std::string& str, bool* pf_invalid)
+std::vector<unsigned char> DecodeBase32(const std::string& str, bool* pf_invalid)
 {
     if (!ValidAsCString(str)) {
         *pf_invalid = true;
         return {};
     }
-    std::vector<unsigned char> vchRet = DecodeBase32(str.c_str(), pf_invalid);
-    return std::string((const char*)vchRet.data(), vchRet.size());
+    return DecodeBase32(str.c_str(), pf_invalid);
 }
 
 namespace {
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
index c87b2d2415..5d85f0580b 100644
--- a/src/util/strencodings.h
+++ b/src/util/strencodings.h
@@ -65,12 +65,12 @@ bool IsHex(std::string_view str);
 */
 bool IsHexNumber(std::string_view str);
 std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid);
-std::string DecodeBase64(const std::string& str, bool* pf_invalid);
+std::vector<unsigned char> DecodeBase64(const std::string& str, bool* pf_invalid);
 std::string EncodeBase64(Span<const unsigned char> input);
 inline std::string EncodeBase64(Span<const std::byte> input) { return EncodeBase64(MakeUCharSpan(input)); }
 inline std::string EncodeBase64(const std::string& str) { return EncodeBase64(MakeUCharSpan(str)); }
 std::vector<unsigned char> DecodeBase32(const char* p, bool* pf_invalid);
-std::string DecodeBase32(const std::string& str, bool* pf_invalid);
+std::vector<unsigned char> DecodeBase32(const std::string& str, bool* pf_invalid);
 
 /**
  * Base32 encode.