Implement EMV initiate application processing

* emv_initiate_application_processing() is responsible for using the DOL
  helper functions to process the PDOL and build the concatenated data,
  as well as determine the outcome of GET PROCESSING OPTIONS in
  accordance with EMV 4.4 Book 4, 6.3.1.
* EMV_OUTCOME_GPO_NOT_ACCEPTED has been added to indicate that the
  processing conditions are not accepted, and is in contrast to
  EMV_OUTCOME_NOT_ACCEPTED which indicates that the card as a whole is
  not accepted. The appropriate action, whether to ignore the
  application and return to application selection, or whether to
  terminate the session, is indicated for the individual processing
  steps in EMV 4.4 Book 4.

src/emv.c

@@ -23,6 +23,8 @@
 #include "emv_utils_config.h"
 #include "emv_tal.h"
 #include "emv_app.h"
+#include "emv_dol.h"
+#include "emv_tags.h"
 
 #include "iso7816.h"
 
@@ -56,6 +58,7 @@ const char* emv_outcome_get_string(enum emv_outcome_t outcome)
 		case EMV_OUTCOME_CARD_BLOCKED: return "Card blocked"; // Not in EMV specification
 		case EMV_OUTCOME_NOT_ACCEPTED: return "Not accepted"; // Message 0C
 		case EMV_OUTCOME_TRY_AGAIN: return "Try again"; // Message 13
+		case EMV_OUTCOME_GPO_NOT_ACCEPTED: return "Not accepted"; // Message 0C
 	}
 
 	return "Invalid outcome";
@@ -431,3 +434,142 @@ int emv_select_application(
 
 	return r;
 }
+
+int emv_initiate_application_processing(
+	struct emv_ttl_t* ttl,
+	struct emv_app_t* selected_app,
+	const struct emv_tlv_list_t* source1,
+	const struct emv_tlv_list_t* source2,
+	struct emv_tlv_list_t* icc
+)
+{
+	int r;
+	const struct emv_tlv_t* pdol;
+	uint8_t gpo_data_buf[255]; // See EMV_CAPDU_DATA_MAX
+	uint8_t* gpo_data;
+	size_t gpo_data_len;
+	struct emv_tlv_list_t gpo_output = EMV_TLV_LIST_INIT;
+
+	if (!ttl || !selected_app || !source1) {
+		emv_debug_trace_msg("ttl=%p, selected_app=%p, source1=%p, source2=%p", ttl, selected_app, source1, source2);
+		emv_debug_error("Invalid parameter");
+		return EMV_ERROR_INVALID_PARAMETER;
+	}
+
+	// Process PDOL, if available
+	// See EMV 4.4 Book 3, 10.1
+	pdol = emv_tlv_list_find(&selected_app->tlv_list, EMV_TAG_9F38_PDOL);
+	if (pdol) {
+		int dol_data_len;
+		size_t gpo_data_offset;
+
+		emv_debug_info_data("PDOL found", pdol->value, pdol->length);
+		dol_data_len = emv_dol_compute_data_length(pdol->value, pdol->length);
+		if (dol_data_len < 0) {
+			emv_debug_trace_msg("emv_dol_compute_data_length() failed; dol_data_len=%d", dol_data_len);
+			emv_debug_error("Failed to compute PDOL data length");
+			return EMV_OUTCOME_CARD_ERROR;
+		}
+		if (dol_data_len > sizeof(gpo_data_buf) - 3) {
+			emv_debug_error("Invalid PDOL data length of %u", dol_data_len);
+			return EMV_OUTCOME_CARD_ERROR;
+		}
+
+		gpo_data = gpo_data_buf;
+		gpo_data_len = sizeof(gpo_data_buf);
+		gpo_data[0] = EMV_TAG_83_COMMAND_TEMPLATE;
+		gpo_data_offset = 1;
+		if (dol_data_len < 0x80) {
+			// Short length form
+			gpo_data[1] = dol_data_len;
+			gpo_data_offset += 1;
+		} else {
+			// Long length form
+			gpo_data[1] = 0x81;
+			gpo_data[2] = dol_data_len;
+			gpo_data_offset += 2;
+		}
+		gpo_data_len -= gpo_data_offset;
+
+		r = emv_dol_build_data(
+			pdol->value,
+			pdol->length,
+			(struct emv_tlv_list_t*)source1,
+			(struct emv_tlv_list_t*)source2,
+			gpo_data + gpo_data_offset,
+			&gpo_data_len
+		);
+		if (r) {
+			emv_debug_trace_msg("emv_dol_build_data() failed; r=%d", r);
+			emv_debug_error("Failed to build PDOL data");
+
+			// This is considered an internal error because the PDOL has
+			// already been sucessfully parsed and the PDOL data length is
+			// already known not to exceed the GPO data buffer.
+			return EMV_ERROR_INTERNAL;
+		}
+
+		gpo_data_len += gpo_data_offset;
+
+	} else {
+		// PDOL not available. emv_ttl_get_processing_options() will build
+		// empty Command Template (field 83) if no GPO data is provided
+		gpo_data = NULL;
+		gpo_data_len = 0;
+	}
+
+	r = emv_tal_get_processing_options(ttl, gpo_data, gpo_data_len, &gpo_output, NULL, NULL);
+	if (r) {
+		emv_debug_trace_msg("emv_tal_get_processing_options() failed; r=%d", r);
+		if (r < 0) {
+			emv_debug_error("Error during application processing; terminate session");
+
+			if (r == EMV_TAL_ERROR_INTERNAL || r == EMV_TAL_ERROR_INVALID_PARAMETER) {
+				r = EMV_ERROR_INTERNAL;
+			} else {
+				// All other GPO errors are card errors
+				r = EMV_OUTCOME_CARD_ERROR;
+			}
+			goto error;
+		}
+		if (r > 0) {
+			emv_debug_info("Failed to initiate application processing");
+
+			if (r == EMV_TAL_RESULT_GPO_CONDITIONS_NOT_SATISFIED) {
+				// Conditions of use not satisfied; ignore app and continue
+				// See EMV 4.4 Book 3, 10.1
+				// See EMV 4.4 Book 4, 6.3.1
+				r = EMV_OUTCOME_GPO_NOT_ACCEPTED;
+			} else {
+				// All other GPO outcomes are card errors
+				r = EMV_OUTCOME_CARD_ERROR;
+			}
+			goto error;
+		}
+	}
+
+	// Move application data to ICC data list
+	*icc = selected_app->tlv_list;
+	selected_app->tlv_list = EMV_TLV_LIST_INIT;
+
+	// Append GPO output to ICC data list
+	r = emv_tlv_list_append(icc, &gpo_output);
+	if (r) {
+		emv_debug_trace_msg("emv_tlv_list_append() failed; r=%d", r);
+
+		// Internal error; terminate session
+		emv_debug_error("Internal error");
+		r = EMV_ERROR_INTERNAL;
+		goto error;
+	}
+
+	// Success
+	r = 0;
+	goto exit;
+
+error:
+	emv_tlv_list_clear(icc);
+	emv_tlv_list_clear(&gpo_output);
+exit:
+	return r;
+}

src/emv.h

@@ -53,6 +53,7 @@ enum emv_outcome_t {
 	EMV_OUTCOME_CARD_BLOCKED = 2, ///< Card blocked
 	EMV_OUTCOME_NOT_ACCEPTED = 3, ///< Card not accepted or no supported applications
 	EMV_OUTCOME_TRY_AGAIN = 4, ///< Try again by selecting a different application
+	EMV_OUTCOME_GPO_NOT_ACCEPTED = 5, ///< Processing conditions not accepted
 };
 
 /**
@@ -138,6 +139,33 @@ int emv_select_application(
 	struct emv_app_t** selected_app
 );
 
+/**
+ * Initiate EMV application processing by assessing the Processing Options
+ * Data Object List (PDOL) and performing GET PROCESSING OPTIONS.
+ * @note Upon success, this function will also move the selected application's
+ *       TLV data to the ICC data output and append the output of
+ *       GET PROCESSING OPTIONS.
+ * @remark See EMV 4.4 Book 3, 10.1
+ * @remark See EMV 4.4 Book 4, 6.3.1
+ *
+ * @param ttl EMV Terminal Transport Layer context
+ * @param selected_app Selected EMV application
+ * @param source1 EMV TLV list used as primary source. Required.
+ * @param source2 EMV TLV list used as secondary source. NULL to ignore.
+ * @param icc ICC data output
+ *
+ * @return Zero for success
+ * @return Less than zero for errors. See @ref emv_error_t
+ * @return Greater than zero for EMV processing outcome. See @ref emv_outcome_t
+ */
+int emv_initiate_application_processing(
+	struct emv_ttl_t* ttl,
+	struct emv_app_t* selected_app,
+	const struct emv_tlv_list_t* source1,
+	const struct emv_tlv_list_t* source2,
+	struct emv_tlv_list_t* icc
+);
+
 __END_DECLS
 
 #endif

tests/CMakeLists.txt

@@ -58,6 +58,10 @@ if (BUILD_TESTING)
 	target_link_libraries(emv_select_application_test PRIVATE emv_cardreader_emul print_helpers emv)
 	add_test(emv_select_application_test emv_select_application_test)
 
+	add_executable(emv_initiate_application_processing_test emv_initiate_application_processing_test.c)
+	target_link_libraries(emv_initiate_application_processing_test PRIVATE emv_cardreader_emul print_helpers emv)
+	add_test(emv_initiate_application_processing_test emv_initiate_application_processing_test)
+
 	add_executable(isocodes_test isocodes_test.c)
 	find_package(Intl)
 	if(Intl_FOUND)