Make DecodeBase{32,64} return optional instead of taking bool*

Author: sipa

src/httprpc.cpp

@@ -132,10 +132,10 @@ static bool RPCAuthorized(const std::string& strAuth, std::string& strAuthUserna
     if (strAuth.substr(0, 6) != "Basic ")
         return false;
     std::string strUserPass64 = TrimString(strAuth.substr(6));
-    bool invalid;
-    std::vector<unsigned char> userpass_data = DecodeBase64(strUserPass64, &invalid);
-    if (invalid) return false;
-    std::string strUserPass(userpass_data.begin(), userpass_data.end());
+    auto userpass_data = DecodeBase64(strUserPass64);
+    std::string strUserPass;
+    if (!userpass_data) return false;
+    strUserPass.assign(userpass_data->begin(), userpass_data->end());
 
     if (strUserPass.find(':') != std::string::npos)
         strAuthUsernameOut = strUserPass.substr(0, strUserPass.find(':'));

src/i2p.cpp

@@ -69,12 +69,11 @@ static std::string SwapBase64(const std::string& from)
 static Binary DecodeI2PBase64(const std::string& i2p_b64)
 {
     const std::string& std_b64 = SwapBase64(i2p_b64);
-    bool invalid;
-    Binary decoded = DecodeBase64(std_b64, &invalid);
-    if (invalid) {
+    auto decoded = DecodeBase64(std_b64);
+    if (!decoded) {
         throw std::runtime_error(strprintf("Cannot decode Base64: \"%s\"", i2p_b64));
     }
-    return decoded;
+    return std::move(*decoded);
 }
 
 /**

src/netaddress.cpp

@@ -234,17 +234,16 @@ bool CNetAddr::SetTor(const std::string& addr)
         return false;
     }
 
-    bool invalid;
-    const auto& input = DecodeBase32(addr.substr(0, addr.size() - suffix_len), &invalid);
+    auto input = DecodeBase32(addr.substr(0, addr.size() - suffix_len));
 
-    if (invalid) {
+    if (!input) {
         return false;
     }
 
-    if (input.size() == torv3::TOTAL_LEN) {
-        Span<const uint8_t> input_pubkey{input.data(), ADDR_TORV3_SIZE};
-        Span<const uint8_t> input_checksum{input.data() + ADDR_TORV3_SIZE, torv3::CHECKSUM_LEN};
-        Span<const uint8_t> input_version{input.data() + ADDR_TORV3_SIZE + torv3::CHECKSUM_LEN, sizeof(torv3::VERSION)};
+    if (input->size() == torv3::TOTAL_LEN) {
+        Span<const uint8_t> input_pubkey{input->data(), ADDR_TORV3_SIZE};
+        Span<const uint8_t> input_checksum{input->data() + ADDR_TORV3_SIZE, torv3::CHECKSUM_LEN};
+        Span<const uint8_t> input_version{input->data() + ADDR_TORV3_SIZE + torv3::CHECKSUM_LEN, sizeof(torv3::VERSION)};
 
         if (input_version != torv3::VERSION) {
             return false;
@@ -280,15 +279,14 @@ bool CNetAddr::SetI2P(const std::string& addr)
     // can decode it.
     const std::string b32_padded = addr.substr(0, b32_len) + "====";
 
-    bool invalid;
-    const auto& address_bytes = DecodeBase32(b32_padded.c_str(), &invalid);
+    auto address_bytes = DecodeBase32(b32_padded);
 
-    if (invalid || address_bytes.size() != ADDR_I2P_SIZE) {
+    if (!address_bytes || address_bytes->size() != ADDR_I2P_SIZE) {
         return false;
     }
 
     m_net = NET_I2P;
-    m_addr.assign(address_bytes.begin(), address_bytes.end());
+    m_addr.assign(address_bytes->begin(), address_bytes->end());
 
     return true;
 }

src/psbt.cpp

@@ -388,13 +388,12 @@ std::string PSBTRoleName(PSBTRole role) {
 
 bool DecodeBase64PSBT(PartiallySignedTransaction& psbt, const std::string& base64_tx, std::string& error)
 {
-    bool invalid;
-    auto tx_data = DecodeBase64(base64_tx, &invalid);
-    if (invalid) {
+    auto tx_data = DecodeBase64(base64_tx);
+    if (!tx_data) {
         error = "invalid base64";
         return false;
     }
-    return DecodeRawPSBT(psbt, MakeByteSpan(tx_data), error);
+    return DecodeRawPSBT(psbt, MakeByteSpan(*tx_data), error);
 }
 
 bool DecodeRawPSBT(PartiallySignedTransaction& psbt, Span<const std::byte> tx_data, std::string& error)

src/qt/walletframe.cpp

@@ -198,12 +198,12 @@ void WalletFrame::gotoLoadPSBT(bool from_clipboard)
 
     if (from_clipboard) {
         std::string raw = QApplication::clipboard()->text().toStdString();
-        bool invalid;
-        data = DecodeBase64(raw, &invalid);
-        if (invalid) {
+        auto result = DecodeBase64(raw);
+        if (!result) {
             Q_EMIT message(tr("Error"), tr("Unable to decode PSBT from clipboard (invalid base64)"), CClientUIInterface::MSG_ERROR);
             return;
         }
+        data = std::move(*result);
     } else {
         QString filename = GUIUtil::getOpenFileName(this,
             tr("Load Transaction Data"), QString(),

src/test/base32_tests.cpp

@@ -22,22 +22,16 @@ BOOST_AUTO_TEST_CASE(base32_testvectors)
         BOOST_CHECK_EQUAL(strEnc, vstrOut[i]);
         strEnc = EncodeBase32(vstrIn[i], false);
         BOOST_CHECK_EQUAL(strEnc, vstrOutNoPadding[i]);
-        bool invalid;
-        auto dec = DecodeBase32(vstrOut[i], &invalid);
-        BOOST_CHECK(!invalid);
-        BOOST_CHECK_MESSAGE(MakeByteSpan(dec) == MakeByteSpan(vstrIn[i]), vstrOut[i]);
+        auto dec = DecodeBase32(vstrOut[i]);
+        BOOST_REQUIRE(dec);
+        BOOST_CHECK_MESSAGE(MakeByteSpan(*dec) == MakeByteSpan(vstrIn[i]), vstrOut[i]);
     }
 
     // Decoding strings with embedded NUL characters should fail
-    bool failure;
-    (void)DecodeBase32("invalid\0"s, &failure); // correct size, invalid due to \0
-    BOOST_CHECK(failure);
-    (void)DecodeBase32("AWSX3VPP"s, &failure); // valid
-    BOOST_CHECK(!failure);
-    (void)DecodeBase32("AWSX3VPP\0invalid"s, &failure); // correct size, invalid due to \0
-    BOOST_CHECK(failure);
-    (void)DecodeBase32("AWSX3VPPinvalid"s, &failure); // invalid size
-    BOOST_CHECK(failure);
+    BOOST_CHECK(!DecodeBase32("invalid\0"s)); // correct size, invalid due to \0
+    BOOST_CHECK(DecodeBase32("AWSX3VPP"s)); // valid
+    BOOST_CHECK(!DecodeBase32("AWSX3VPP\0invalid"s)); // correct size, invalid due to \0
+    BOOST_CHECK(!DecodeBase32("AWSX3VPPinvalid"s)); // invalid size
 }
 
 BOOST_AUTO_TEST_SUITE_END()

src/test/base64_tests.cpp

@@ -19,10 +19,9 @@ BOOST_AUTO_TEST_CASE(base64_testvectors)
     {
         std::string strEnc = EncodeBase64(vstrIn[i]);
         BOOST_CHECK_EQUAL(strEnc, vstrOut[i]);
-        bool invalid;
-        auto dec = DecodeBase64(strEnc, &invalid);
-        BOOST_CHECK(!invalid);
-        BOOST_CHECK_MESSAGE(MakeByteSpan(dec) == MakeByteSpan(vstrIn[i]), vstrOut[i]);
+        auto dec = DecodeBase64(strEnc);
+        BOOST_REQUIRE(dec);
+        BOOST_CHECK_MESSAGE(MakeByteSpan(*dec) == MakeByteSpan(vstrIn[i]), vstrOut[i]);
     }
 
     {
@@ -36,15 +35,10 @@ BOOST_AUTO_TEST_CASE(base64_testvectors)
     }
 
     // Decoding strings with embedded NUL characters should fail
-    bool failure;
-    (void)DecodeBase64("invalid\0"s, &failure);
-    BOOST_CHECK(failure);
-    (void)DecodeBase64("nQB/pZw="s, &failure);
-    BOOST_CHECK(!failure);
-    (void)DecodeBase64("nQB/pZw=\0invalid"s, &failure);
-    BOOST_CHECK(failure);
-    (void)DecodeBase64("nQB/pZw=invalid\0"s, &failure);
-    BOOST_CHECK(failure);
+    BOOST_CHECK(!DecodeBase64("invalid\0"s));
+    BOOST_CHECK(DecodeBase64("nQB/pZw="s));
+    BOOST_CHECK(!DecodeBase64("nQB/pZw=\0invalid"s));
+    BOOST_CHECK(!DecodeBase64("nQB/pZw=invalid\0"s));
 }
 
 BOOST_AUTO_TEST_SUITE_END()

src/test/fuzz/base_encode_decode.cpp

@@ -36,17 +36,16 @@ FUZZ_TARGET_INIT(base_encode_decode, initialize_base_encode_decode)
         assert(ToLower(encoded_string) == ToLower(TrimString(random_encoded_string)));
     }
 
-    bool pf_invalid;
-    decoded = DecodeBase32(random_encoded_string, &pf_invalid);
-    if (!pf_invalid) {
-        const std::string encoded_string = EncodeBase32(decoded);
+    auto result = DecodeBase32(random_encoded_string);
+    if (result) {
+        const std::string encoded_string = EncodeBase32(*result);
         assert(encoded_string == TrimString(encoded_string));
         assert(ToLower(encoded_string) == ToLower(TrimString(random_encoded_string)));
     }
 
-    decoded = DecodeBase64(random_encoded_string, &pf_invalid);
-    if (!pf_invalid) {
-        const std::string encoded_string = EncodeBase64(decoded);
+    result = DecodeBase64(random_encoded_string);
+    if (result) {
+        const std::string encoded_string = EncodeBase64(*result);
         assert(encoded_string == TrimString(encoded_string));
         assert(ToLower(encoded_string) == ToLower(TrimString(random_encoded_string)));
     }

src/util/message.cpp

@@ -35,14 +35,13 @@ MessageVerificationResult MessageVerify(
         return MessageVerificationResult::ERR_ADDRESS_NO_KEY;
     }
 
-    bool invalid = false;
-    std::vector<unsigned char> signature_bytes = DecodeBase64(signature, &invalid);
-    if (invalid) {
+    auto signature_bytes = DecodeBase64(signature);
+    if (!signature_bytes) {
         return MessageVerificationResult::ERR_MALFORMED_SIGNATURE;
     }
 
     CPubKey pubkey;
-    if (!pubkey.RecoverCompact(MessageHash(message), signature_bytes)) {
+    if (!pubkey.RecoverCompact(MessageHash(message), *signature_bytes)) {
         return MessageVerificationResult::ERR_PUBKEY_NOT_RECOVERED;
     }
 

src/util/strencodings.cpp

@@ -126,7 +126,7 @@ std::string EncodeBase64(Span<const unsigned char> input)
     return str;
 }
 
-std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid)
+std::optional<std::vector<unsigned char>> DecodeBase64(const char* p)
 {
     static const int8_t decode64_table[256]{
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@@ -167,18 +167,17 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pf_invalid)
         ++p;
     }
     valid = valid && (p - e) % 4 == 0 && p - q < 4;
-    *pf_invalid = !valid;
+    if (!valid) return {};
 
     return ret;
 }
 
-std::vector<unsigned char> DecodeBase64(const std::string& str, bool* pf_invalid)
+std::optional<std::vector<unsigned char>> DecodeBase64(const std::string& str)
 {
     if (!ValidAsCString(str)) {
-        *pf_invalid = true;
         return {};
     }
-    return DecodeBase64(str.c_str(), pf_invalid);
+    return DecodeBase64(str.c_str());
 }
 
 std::string EncodeBase32(Span<const unsigned char> input, bool pad)
@@ -201,7 +200,7 @@ std::string EncodeBase32(const std::string& str, bool pad)
     return EncodeBase32(MakeUCharSpan(str), pad);
 }
 
-std::vector<unsigned char> DecodeBase32(const char* p, bool* pf_invalid)
+std::optional<std::vector<unsigned char>> DecodeBase32(const char* p)
 {
     static const int8_t decode32_table[256]{
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@@ -242,18 +241,17 @@ std::vector<unsigned char> DecodeBase32(const char* p, bool* pf_invalid)
         ++p;
     }
     valid = valid && (p - e) % 8 == 0 && p - q < 8;
-    *pf_invalid = !valid;
+    if (!valid) return {};
 
     return ret;
 }
 
-std::vector<unsigned char> DecodeBase32(const std::string& str, bool* pf_invalid)
+std::optional<std::vector<unsigned char>> DecodeBase32(const std::string& str)
 {
     if (!ValidAsCString(str)) {
-        *pf_invalid = true;
         return {};
     }
-    return DecodeBase32(str.c_str(), pf_invalid);
+    return DecodeBase32(str.c_str());
 }
 
 namespace {