Use CommandAPDU instead byte_vector

Signed-off-by: Raul Metsma <[email protected]>

Author: metsma

lib/libpcsc-cpp/include/pcsc-cpp/pcsc-cpp.hpp

@@ -165,9 +165,15 @@ struct CommandApdu
         d.push_back(le);
     }
 
-    virtual ~CommandApdu() noexcept = default;
+    PCSC_CPP_CONSTEXPR_VECTOR CommandApdu(const CommandApdu &other, byte_type le) :
+        d(other.d)
+    {
+        size_t pos = d.size() <= 5 ? 4 : 5 + d[4]; // Case 1/2 or 3/4
+        d.resize(pos + 1);
+        d[pos] = le;
+    }
 
-    constexpr operator const byte_vector&() const { return d; }
+    virtual ~CommandApdu() = default;
 
     /**
      * A helper function to create a SELECT FILE command APDU.
@@ -249,6 +255,21 @@ struct CommandApdu
         return VerifyApdu {0x00, 0x20, 0x00, p2, std::move(pin)};
     }
 
+    /**
+     * A helper function to create a GET RESPONSE command APDU.
+     *
+     * The ISO 7816-4 Section 7.1 GET RESPONSE  command has the form:
+     *   CLA = 0x00
+     *   INS = 0xC0
+     *   P1, P2 = ‘0000’ (other values are RFU)
+     *   Lc and Data field = Empty
+     *   Le  = Maximum length of data expected in response
+     */
+    static PCSC_CPP_CONSTEXPR_VECTOR CommandApdu getResponse(byte_type le = 0x00)
+    {
+        return {0x00, 0xc0, 0x00, 0x00, le};
+    }
+
     byte_vector d;
 };
 

lib/libpcsc-cpp/src/SmartCard.cpp

@@ -142,29 +142,16 @@ class CardImpl
             || features.contains(FEATURE_VERIFY_PIN_DIRECT);
     }
 
-    ResponseApdu transmitBytes(const byte_vector& commandBytes) const
+    ResponseApdu transmitBytes(const CommandApdu& commandApdu) const
     {
         byte_vector responseBytes(ResponseApdu::MAX_SIZE, 0);
         auto responseLength = DWORD(responseBytes.size());
-
-        // TODO: debug("Sending:  " + bytes2hexstr(commandBytes))
-
-        SCard(Transmit, cardHandle, &_protocol, commandBytes.data(), DWORD(commandBytes.size()),
+        SCard(Transmit, cardHandle, &_protocol, commandApdu.d.data(), DWORD(commandApdu.d.size()),
               nullptr, responseBytes.data(), &responseLength);
-
-        auto response = toResponse(std::move(responseBytes), responseLength);
-
-        if (response.sw1 == ResponseApdu::WRONG_LE_LENGTH) {
-            getResponseWithLE(response, commandBytes);
-        }
-        if (response.sw1 == ResponseApdu::MORE_DATA_AVAILABLE) {
-            getMoreResponseData(response);
-        }
-
-        return response;
+        return toResponse(std::move(responseBytes), responseLength);
     }
 
-    ResponseApdu transmitBytesCTL(const byte_vector& commandBytes, uint16_t lang,
+    ResponseApdu transmitBytesCTL(const CommandApdu& commandApdu, uint16_t lang,
                                   uint8_t minlen) const
     {
         uint8_t PINFrameOffset = 0;
@@ -182,8 +169,8 @@ class CardImpl
         data->bNumberMessage = CCIDDefaultInvitationMessage;
         data->wLangId = lang;
         data->bMsgIndex = NoInvitationMessage;
-        data->ulDataLength = uint32_t(commandBytes.size());
-        cmd.insert(cmd.cend(), commandBytes.cbegin(), commandBytes.cend());
+        data->ulDataLength = uint32_t(commandApdu.d.size());
+        cmd.insert(cmd.cend(), commandApdu.d.cbegin(), commandApdu.d.cend());
 
         DWORD ioctl =
             features.at(features.contains(FEATURE_VERIFY_PIN_START) ? FEATURE_VERIFY_PIN_START
@@ -266,31 +253,6 @@ class CardImpl
                       + std::to_string(_protocol.dwProtocol));
         }
     }
-
-    void getMoreResponseData(ResponseApdu& response) const
-    {
-        byte_vector getResponseCommand {0x00, 0xc0, 0x00, 0x00, 0x00};
-
-        ResponseApdu newResponse {response.sw1, response.sw2};
-
-        while (newResponse.sw1 == ResponseApdu::MORE_DATA_AVAILABLE) {
-            getResponseCommand[4] = newResponse.sw2;
-            newResponse = transmitBytes(getResponseCommand);
-            response.data.insert(response.data.end(), newResponse.data.cbegin(),
-                                 newResponse.data.cend());
-        }
-
-        response.sw1 = ResponseApdu::OK;
-        response.sw2 = 0;
-    }
-
-    void getResponseWithLE(ResponseApdu& response, byte_vector command) const
-    {
-        size_t pos = command.size() <= 5 ? 4 : 5 + command[4]; // Case 1/2 or 3/4
-        command.resize(pos + 1);
-        command[pos] = response.sw2;
-        response = transmitBytes(command);
-    }
 };
 
 SmartCard::Session::Session(const CardImpl& card) : card(card)
@@ -309,7 +271,22 @@ SmartCard::Session::~Session() noexcept
 
 ResponseApdu SmartCard::Session::transmit(const CommandApdu& command) const
 {
-    return card.transmitBytes(command);
+    auto response = card.transmitBytes(command);
+    if (response.sw1 == ResponseApdu::WRONG_LE_LENGTH) {
+        response = card.transmitBytes(CommandApdu(command, response.sw2));
+    }
+    if (response.sw1 == ResponseApdu::MORE_DATA_AVAILABLE) {
+        auto getResponseCommand = CommandApdu::getResponse();
+        while (response.sw1 == ResponseApdu::MORE_DATA_AVAILABLE) {
+            getResponseCommand.d[4] = response.sw2;
+            auto newResponse = card.transmitBytes(getResponseCommand);
+            response.sw1 = newResponse.sw1;
+            response.sw2 = newResponse.sw2;
+            response.data.insert(response.data.end(), newResponse.data.cbegin(),
+                                 newResponse.data.cend());
+        }
+    }
+    return response;
 }
 
 ResponseApdu SmartCard::Session::transmitCTL(const CommandApdu& command, uint16_t lang,