Implement PC/SC reader property retrieval

The pcsc_reader_get_property() function can be used to retrieve any specific property if supported by the PC/SC reader while this project only provides property definitions for properties that are likely to be of interest to this project in future. Also stringify these properties in emv-tool.
openemv · Apr 14, 2024 · 489cac2 · 489cac2
1 parent 831cca9
commit 489cac2
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Showing 4 changed files with 559 additions and 49 deletions.
diff --git a/src/pcsc.c b/src/pcsc.c
@@ -30,6 +30,13 @@
 #include <stdio.h>
 #include <string.h>
 
+// For ntohl and friends
+#if defined(HAVE_ARPA_INET_H)
+#include <arpa/inet.h>
+#elif defined(HAVE_WINSOCK_H)
+#include <winsock.h>
+#endif
+
 #ifndef USE_PCSCLITE
 // Only PCSCLite provides pcsc_stringify_error()
 static const char* pcsc_stringify_error(unsigned int result)
@@ -55,6 +62,22 @@ struct pcsc_reader_features_t {
 	// Populated by SCardControl(CM_IOCTL_GET_FEATURE_REQUEST)
 	uint8_t buf[MAX_BUFFER_SIZE];
 	DWORD buf_len;
+
+	// Populated by SCardControl(IFD_PIN_PROPERTIES)
+	PIN_PROPERTIES_STRUCTURE pin_properties;
+	DWORD pin_properties_len;
+
+	// Populated by SCardControl(IFD_DISPLAY_PROPERTIES)
+	struct {
+		uint16_t wLcdMaxCharacters;
+		uint16_t wLcdMaxLines;
+	} __attribute__((packed))
+	display_properties;
+	DWORD display_properties_len;
+
+	// Populated by SCardControl(GET_TLV_PROPERTIES)
+	uint8_t properties[MAX_BUFFER_SIZE];
+	DWORD properties_len;
 };
 
 struct pcsc_reader_t {
@@ -81,6 +104,7 @@ struct pcsc_reader_t {
 
 // Helper functions
 static int pcsc_reader_populate_features(struct pcsc_reader_t* reader);
+static int pcsc_reader_get_feature(struct pcsc_reader_t* reader, unsigned int feature, LPDWORD control_code);
 static int pcsc_reader_internal_get_uid(pcsc_reader_ctx_t reader_ctx, uint8_t* uid, size_t* uid_len);
 
 int pcsc_init(pcsc_ctx_t* ctx)
@@ -166,6 +190,7 @@ static int pcsc_reader_populate_features(struct pcsc_reader_t* reader)
 	SCARDHANDLE card;
 	DWORD protocol;
 	const PCSC_TLV_STRUCTURE* pcsc_tlv;
+	DWORD control_code;
 
 	if (!reader) {
 		return -1;
@@ -223,6 +248,87 @@ static int pcsc_reader_populate_features(struct pcsc_reader_t* reader)
 		++pcsc_tlv;
 	}
 
+	r = pcsc_reader_get_feature(reader, FEATURE_IFD_PIN_PROPERTIES, &control_code);
+	if (r < 0) {
+		r = -6;
+		goto exit;
+	}
+	if (r == 0) {
+		// Request reader TLV properties
+		result = SCardControl(
+			card,
+			control_code,
+			NULL,
+			0,
+			&reader->features.pin_properties,
+			sizeof(reader->features.pin_properties),
+			&reader->features.pin_properties_len
+		);
+		if (result != SCARD_S_SUCCESS) {
+			fprintf(stderr, "SCardControl(%04X) failed; result=0x%x [%s]\n", (unsigned int)control_code, (unsigned int)result, pcsc_stringify_error(result));
+			r = -7;
+			goto exit;
+		}
+		if (reader->features.pin_properties_len != sizeof(reader->features.pin_properties)) {
+			fprintf(stderr, "Failed to parse PC/SC reader IFD PIN properties\n");
+			reader->features.pin_properties_len = 0; // Invalidate buffer length
+			r = -8;
+			goto exit;
+		}
+	}
+
+	r = pcsc_reader_get_feature(reader, FEATURE_IFD_DISPLAY_PROPERTIES, &control_code);
+	if (r < 0) {
+		r = -9;
+		goto exit;
+	}
+	if (r == 0) {
+		// Request reader TLV properties
+		result = SCardControl(
+			card,
+			control_code,
+			NULL,
+			0,
+			&reader->features.display_properties,
+			sizeof(reader->features.display_properties),
+			&reader->features.display_properties_len
+		);
+		if (result != SCARD_S_SUCCESS) {
+			fprintf(stderr, "SCardControl(%04X) failed; result=0x%x [%s]\n", (unsigned int)control_code, (unsigned int)result, pcsc_stringify_error(result));
+			r = -10;
+			goto exit;
+		}
+		if (reader->features.display_properties_len != sizeof(reader->features.display_properties)) {
+			fprintf(stderr, "Failed to parse PC/SC reader IFD display properties\n");
+			reader->features.display_properties_len = 0; // Invalidate buffer length
+			r = -11;
+			goto exit;
+		}
+	}
+
+	r = pcsc_reader_get_feature(reader, FEATURE_GET_TLV_PROPERTIES, &control_code);
+	if (r < 0) {
+		r = -12;
+		goto exit;
+	}
+	if (r == 0) {
+		// Request reader TLV properties
+		result = SCardControl(
+			card,
+			control_code,
+			NULL,
+			0,
+			reader->features.properties,
+			sizeof(reader->features.properties),
+			&reader->features.properties_len
+		);
+		if (result != SCARD_S_SUCCESS) {
+			fprintf(stderr, "SCardControl(%04X) failed; result=0x%x [%s]\n", (unsigned int)control_code, (unsigned int)result, pcsc_stringify_error(result));
+			r = -13;
+			goto exit;
+		}
+	}
+
 	// Success
 	r = 0;
 	goto exit;
@@ -238,6 +344,34 @@ static int pcsc_reader_populate_features(struct pcsc_reader_t* reader)
 	return r;
 }
 
+static int pcsc_reader_get_feature(
+	struct pcsc_reader_t* reader,
+	unsigned int feature,
+	LPDWORD control_code
+)
+{
+	const PCSC_TLV_STRUCTURE* pcsc_tlv;
+
+	if (!reader) {
+		return -1;
+	}
+
+	if (!reader->features.buf_len) {
+		return 1;
+	}
+
+	pcsc_tlv = (PCSC_TLV_STRUCTURE*)reader->features.buf;
+	while ((void*)pcsc_tlv - (void*)reader->features.buf < reader->features.buf_len) {
+		if (pcsc_tlv->tag == feature && pcsc_tlv->length == 4) {
+			*control_code = ntohl(pcsc_tlv->value);
+			return 0;
+		}
+		++pcsc_tlv;
+	}
+
+	return 1;
+}
+
 void pcsc_release(pcsc_ctx_t* ctx)
 {
 	struct pcsc_t* pcsc;
@@ -339,6 +473,104 @@ bool pcsc_reader_has_feature(pcsc_reader_ctx_t reader_ctx, unsigned int feature)
 	return false;
 }
 
+int pcsc_reader_get_property(
+	pcsc_reader_ctx_t reader_ctx,
+	unsigned int property,
+	void* value,
+	size_t* value_len
+)
+{
+	struct pcsc_reader_t* reader;
+	const uint8_t* tlv;
+	size_t tlv_len;
+
+	if (!reader_ctx || !value || !value_len) {
+		return -1;
+	}
+	reader = reader_ctx;
+
+	// Retrieve from GET_TLV_PROPERTIES
+	// See PC/SC Part 10 Rev 2.02.09, 2.6.14
+	tlv = reader->features.properties;
+	tlv_len = reader->features.properties_len;
+	while (tlv_len >= 2) { // 1-byte tag and 1-byte length
+		if (tlv[0] == property) {
+			if (tlv[1] > tlv_len - 2) {
+				*value_len = 0;
+				return -2;
+			}
+			if (tlv[1] > *value_len) {
+				*value_len = 0;
+				return -3;
+			}
+
+			memcpy(value, tlv + 2, tlv[1]);
+			*value_len = tlv[1];
+			return 0;
+		}
+
+		tlv += (2 + tlv[1]);
+		tlv_len -= (2 + tlv[1]);
+	}
+
+	// Otherwise, retrieve from IFD_PIN_PROPERTIES
+	// See PC/SC Part 10 Rev 2.02.09, 2.5.5
+	if (reader->features.pin_properties_len) {
+		if (property == PCSC_PROPERTY_wLcdLayout) {
+			if (*value_len < sizeof(reader->features.pin_properties.wLcdLayout)) {
+				*value_len = 0;
+				return -4;
+			}
+
+			memcpy(
+				value,
+				&reader->features.pin_properties.wLcdLayout,
+				sizeof(reader->features.pin_properties.wLcdLayout)
+			);
+			*value_len = sizeof(reader->features.pin_properties.wLcdLayout);
+			return 0;
+		}
+	}
+
+	// Otherwise, retrieve from IFD_DISPLAY_PROPERTIES
+	// See PC/SC Part 10 Rev 2.02.09, 2.5.6
+	if (reader->features.display_properties_len) {
+		if (property == PCSC_PROPERTY_wLcdMaxCharacters) {
+			if (*value_len < sizeof(reader->features.display_properties.wLcdMaxCharacters)) {
+				*value_len = 0;
+				return -5;
+			}
+
+			memcpy(
+				value,
+				&reader->features.display_properties.wLcdMaxCharacters,
+				sizeof(reader->features.display_properties.wLcdMaxCharacters)
+			);
+			*value_len = sizeof(reader->features.display_properties.wLcdMaxCharacters);
+			return 0;
+		}
+
+		if (property == PCSC_PROPERTY_wLcdMaxLines) {
+			if (*value_len < sizeof(reader->features.display_properties.wLcdMaxLines)) {
+				*value_len = 0;
+				return -6;
+			}
+
+			memcpy(
+				value,
+				&reader->features.display_properties.wLcdMaxLines,
+				sizeof(reader->features.display_properties.wLcdMaxLines)
+			);
+			*value_len = sizeof(reader->features.display_properties.wLcdMaxLines);
+			return 0;
+		}
+	}
+
+	// Property not found
+	*value_len = 0;
+	return 1;
+}
+
 int pcsc_reader_get_state(pcsc_reader_ctx_t reader_ctx, unsigned int* state)
 {
 	struct pcsc_reader_t* reader;

diff --git a/src/pcsc.h b/src/pcsc.h
@@ -45,6 +45,21 @@ typedef void* pcsc_reader_ctx_t; ///< PC/SC reader context pointer type
 #define PCSC_FEATURE_MCT_UNIVERSAL              (0x09) ///< Multifunctional Card Terminal (MCT) universal commands
 /// @}
 
+/**
+ * @name PC/SC reader properties
+ * @remark See PC/SC Part 10 Rev 2.02.09, 2.6.14
+ * @anchor pcsc-reader-properties
+ */
+/// @{
+#define PCSC_PROPERTY_wLcdLayout                (0x01) ///< LCD Layout (from USB CCID wLcdLayout field)
+#define PCSC_PROPERTY_wLcdMaxCharacters         (0x04) ///< Maximum number of characters on a single line of LCD (from USB CCID wLcdLayout field)
+#define PCSC_PROPERTY_wLcdMaxLines              (0x05) ///< Maximum number of lines of LCD (from USB CCID wLcdLayout field)
+#define PCSC_PROPERTY_bMinPINSize               (0x06) ///< Minimum PIN size accepted by the reader
+#define PCSC_PROPERTY_bMaxPINSize               (0x07) ///< Maximum PIN size accepted by the reader
+#define PCSC_PROPERTY_wIdVendor                 (0x0B) ///< USB Vendor ID (from USB idVendor field)
+#define PCSC_PROPERTY_wIdProduct                (0x0C) ///< USB Product ID (from USB idProduct field)
+/// @}
+
 /**
  * @name PC/SC reader states
  * @remark These are derived from PCSCLite's SCARD_STATE_* defines
@@ -117,6 +132,21 @@ const char* pcsc_reader_get_name(pcsc_reader_ctx_t reader_ctx);
  */
 bool pcsc_reader_has_feature(pcsc_reader_ctx_t reader_ctx, unsigned int feature);
 
+/**
+ * Retrieve PC/SC reader property value
+ * @param reader_ctx PC/SC reader context
+ * @param property PC/SC property to retrieve. See @ref pcsc-reader-properties "PC/SC reader properties"
+ * @param value Value buffer output
+ * @param value_len Length of value buffer in bytes
+ * @return Zero for success. Less than zero for error. Greater than zero if not found.
+ */
+int pcsc_reader_get_property(
+	pcsc_reader_ctx_t reader_ctx,
+	unsigned int property,
+	void* value,
+	size_t* value_len
+);
+
 /**
  * Retrieve PC/SC reader state
  * @param reader_ctx PC/SC reader context

diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
@@ -45,6 +45,22 @@ else()
 	set(PCSC_LIBRARIES PCSCLite::PCSCLite)
 endif()
 
+# Check for headers that provide ntohl/htonl and friends
+include(CheckIncludeFile)
+CHECK_INCLUDE_FILE(
+	arpa/inet.h
+	HAVE_ARPA_INET_H
+)
+CHECK_INCLUDE_FILE(
+	winsock.h
+	HAVE_WINSOCK_H
+)
+if(NOT HAVE_ARPA_INET_H AND NOT HAVE_WINSOCK_H)
+	if(BUILD_EMV_TOOL)
+		message(FATAL_ERROR "Failed to find either arpa/inet.h or winsock.h. This is required to build emv-tool.")
+	endif()
+endif()
+
 include(GNUInstallDirs) # Provides CMAKE_INSTALL_* variables and good defaults for install()
 
 # Print helpers object library
@@ -74,9 +90,21 @@ endif()
 # EMV processing command line tool
 if(BUILD_EMV_TOOL)
 	if(PCSCLite_FOUND)
-		set_source_files_properties(../src/pcsc.c
-			PROPERTIES
-				COMPILE_DEFINITIONS USE_PCSCLITE
+		set_property(
+			SOURCE ../src/pcsc.c
+			APPEND PROPERTY COMPILE_DEFINITIONS USE_PCSCLITE
+		)
+	endif()
+	if(HAVE_ARPA_INET_H)
+		set_property(
+			SOURCE ../src/pcsc.c
+			APPEND PROPERTY COMPILE_DEFINITIONS HAVE_ARPA_INET_H
+		)
+	endif()
+	if(HAVE_WINSOCK_H)
+		set_property(
+			SOURCE ../src/pcsc.c
+			APPEND PROPERTY COMPILE_DEFINITIONS HAVE_WINSOCK_H
 		)
 	endif()
 
@@ -88,6 +116,9 @@ if(BUILD_EMV_TOOL)
 	if(PCSC_LIBRARIES)
 		target_link_libraries(emv-tool PRIVATE ${PCSC_LIBRARIES})
 	endif()
+	if(HAVE_WINSOCK_H AND NOT HAVE_ARPA_INET_H)
+		target_link_libraries(emv-tool PRIVATE ws2_32)
+	endif()
 
 	install(
 		TARGETS