--- /dev/null
+//-----------------------------------------------------------------------------
+// Frederik Möllers - August 2012
+//
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Routines to support the German eletronic "Personalausweis" (ID card)
+// Note that the functions which do not implement USB commands do NOT initialize
+// the card (with iso14443a_select_card etc.). If You want to use these
+// functions, You need to do the setup before calling them!
+//-----------------------------------------------------------------------------
+
+#include "iso14443a.h"
+
+#include "epa.h"
+
+// Protocol and Parameter Selection Request
+// use regular (1x) speed in both directions
+// CRC is already included
+static const uint8_t pps[] = {0xD0, 0x11, 0x00, 0x52, 0xA6};
+
+// APDUs for communication with German Identification Card
+
+// General Authenticate (request encrypted nonce) WITHOUT the Le at the end
+static const uint8_t apdu_general_authenticate_pace_get_nonce[] = {
+ 0x10, // CLA
+ 0x86, // INS
+ 0x00, // P1
+ 0x00, // P2
+ 0x02, // Lc
+ 0x7C, // Type: Dynamic Authentication Data
+ 0x00, // Length: 0 bytes
+};
+
+// MSE: Set AT (only CLA, INS, P1 and P2)
+static const uint8_t apdu_mse_set_at_start[] = {
+ 0x00, // CLA
+ 0x22, // INS
+ 0xC1, // P1
+ 0xA4, // P2
+};
+
+// SELECT BINARY with the ID for EF.CardAccess
+static const uint8_t apdu_select_binary_cardaccess[] = {
+ 0x00, // CLA
+ 0xA4, // INS
+ 0x02, // P1
+ 0x0C, // P2
+ 0x02, // Lc
+ 0x01, // ID
+ 0x1C // ID
+};
+
+// READ BINARY
+static const uint8_t apdu_read_binary[] = {
+ 0x00, // CLA
+ 0xB0, // INS
+ 0x00, // P1
+ 0x00, // P2
+ 0x38 // Le
+};
+
+
+// the leading bytes of a PACE OID
+static const uint8_t oid_pace_start[] = {
+ 0x04, // itu-t, identified-organization
+ 0x00, // etsi
+ 0x7F, // reserved
+ 0x00, // etsi-identified-organization
+ 0x07, // bsi-de
+ 0x02, // protocols
+ 0x02, // smartcard
+ 0x04 // id-PACE
+};
+
+//-----------------------------------------------------------------------------
+// Closes the communication channel and turns off the field
+//-----------------------------------------------------------------------------
+void EPA_Finish()
+{
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+ LEDsoff();
+}
+
+//-----------------------------------------------------------------------------
+// Parses DER encoded data, e.g. from EF.CardAccess and fills out the given
+// structs. If a pointer is 0, it is ignored.
+// The function returns 0 on success and if an error occured, it returns the
+// offset where it occured.
+//
+// TODO: This function can access memory outside of the given data if the DER
+// encoding is broken
+// TODO: Support skipping elements with a length > 0x7F
+// TODO: Support OIDs with a length > 7F
+// TODO: Support elements with long tags (tag is longer than 1 byte)
+// TODO: Support proprietary PACE domain parameters
+//-----------------------------------------------------------------------------
+size_t EPA_Parse_CardAccess(uint8_t *data,
+ size_t length,
+ pace_version_info_t *pace_info)
+{
+ size_t index = 0;
+
+ while (index <= length - 2) {
+ // determine type of element
+ // SET or SEQUENCE
+ if (data[index] == 0x31 || data[index] == 0x30) {
+ // enter the set (skip tag + length)
+ index += 2;
+ // extended length
+ if ((data[index - 1] & 0x80) != 0) {
+ index += (data[index] & 0x7F);
+ }
+ }
+ // OID
+ else if (data[index] == 0x06) {
+ // is this a PACE OID?
+ if (data[index + 1] == 0x0A // length matches
+ && memcmp(data + index + 2,
+ oid_pace_start,
+ sizeof(oid_pace_start)) == 0 // content matches
+ && pace_info != NULL)
+ {
+ // first, clear the pace_info struct
+ memset(pace_info, 0, sizeof(pace_version_info_t));
+ memcpy(pace_info->oid, data + index + 2, sizeof(pace_info->oid));
+ // a PACE OID is followed by the version
+ index += data[index + 1] + 2;
+ if (data[index] == 02 && data[index + 1] == 01) {
+ pace_info->version = data[index + 2];
+ index += 3;
+ }
+ else {
+ return index;
+ }
+ // after that there might(!) be the parameter ID
+ if (data[index] == 02 && data[index + 1] == 01) {
+ pace_info->parameter_id = data[index + 2];
+ index += 3;
+ }
+ }
+ else {
+ // skip this OID
+ index += 2 + data[index + 1];
+ }
+ }
+ // if the length is 0, something is wrong
+ // TODO: This needs to be extended to support long tags
+ else if (data[index + 1] == 0) {
+ return index;
+ }
+ else {
+ // skip this part
+ // TODO: This needs to be extended to support long tags
+ // TODO: This needs to be extended to support unknown elements with
+ // a size > 0x7F
+ index += 2 + data[index + 1];
+ }
+ }
+
+ // TODO: We should check whether we reached the end in error, but for that
+ // we need a better parser (e.g. with states like IN_SET or IN_PACE_INFO)
+ return 0;
+}
+
+//-----------------------------------------------------------------------------
+// Read the file EF.CardAccess and save it into a buffer (at most max_length bytes)
+// Returns -1 on failure or the length of the data on success
+// TODO: for the moment this sends only 1 APDU regardless of the requested length
+//-----------------------------------------------------------------------------
+int EPA_Read_CardAccess(uint8_t *buffer, size_t max_length)
+{
+ // the response APDU of the card
+ // since the card doesn't always care for the expected length we send it,
+ // we reserve 262 bytes here just to be safe (256-byte APDU + SW + ISO frame)
+ uint8_t response_apdu[262];
+ int rapdu_length = 0;
+
+ // select the file EF.CardAccess
+ rapdu_length = iso14_apdu((uint8_t *)apdu_select_binary_cardaccess,
+ sizeof(apdu_select_binary_cardaccess),
+ response_apdu);
+ if (rapdu_length != 6
+ || response_apdu[rapdu_length - 4] != 0x90
+ || response_apdu[rapdu_length - 3] != 0x00)
+ {
+ return -1;
+ }
+
+ // read the file
+ rapdu_length = iso14_apdu((uint8_t *)apdu_read_binary,
+ sizeof(apdu_read_binary),
+ response_apdu);
+ if (rapdu_length <= 6
+ || response_apdu[rapdu_length - 4] != 0x90
+ || response_apdu[rapdu_length - 3] != 0x00)
+ {
+ return -1;
+ }
+
+ // copy the content into the buffer
+ // length of data available: apdu_length - 4 (ISO frame) - 2 (SW)
+ size_t to_copy = rapdu_length - 6;
+ to_copy = to_copy < max_length ? to_copy : max_length;
+ memcpy(buffer, response_apdu+2, to_copy);
+ return to_copy;
+}
+
+//-----------------------------------------------------------------------------
+// Abort helper function for EPA_PACE_Collect_Nonce
+// sets relevant data in ack, sends the response
+//-----------------------------------------------------------------------------
+static void EPA_PACE_Collect_Nonce_Abort(UsbCommand *ack, uint8_t step, int func_return)
+{
+ // step in which the failure occured
+ ack->arg[0] = step;
+ // last return code
+ ack->arg[1] = func_return;
+
+ // send the USB packet
+ UsbSendPacket((void *)ack, sizeof(UsbCommand));
+
+ // power down the field
+ EPA_Finish();
+}
+
+//-----------------------------------------------------------------------------
+// Acquire one encrypted PACE nonce
+//-----------------------------------------------------------------------------
+void EPA_PACE_Collect_Nonce(UsbCommand *c, UsbCommand *ack)
+{
+ /*
+ * ack layout:
+ * arg:
+ * 1. element
+ * step where the error occured or 0 if no error occured
+ * 2. element
+ * return code of the last executed function
+ * d:
+ * Encrypted nonce
+ */
+
+ // return value of a function
+ int func_return;
+
+ // initialize ack with 0s
+ memset(ack->arg, 0, 12);
+ memset(ack->d.asBytes, 0, 48);
+
+ // set up communication
+ func_return = EPA_Setup();
+ if (func_return != 0) {
+ EPA_PACE_Collect_Nonce_Abort(ack, 1, func_return);
+ return;
+ }
+
+ // increase the timeout (at least some cards really do need this!)
+ iso14a_set_timeout(0x0002FFFF);
+
+ // read the CardAccess file
+ // this array will hold the CardAccess file
+ uint8_t card_access[256] = {0};
+ int card_access_length = EPA_Read_CardAccess(card_access, 256);
+ // the response has to be at least this big to hold the OID
+ if (card_access_length < 18) {
+ EPA_PACE_Collect_Nonce_Abort(ack, 2, card_access_length);
+ return;
+ }
+
+ // this will hold the PACE info of the card
+ pace_version_info_t pace_version_info;
+ // search for the PACE OID
+ func_return = EPA_Parse_CardAccess(card_access,
+ card_access_length,
+ &pace_version_info);
+ if (func_return != 0 || pace_version_info.version == 0) {
+ EPA_PACE_Collect_Nonce_Abort(ack, 3, func_return);
+ return;
+ }
+
+ // initiate the PACE protocol
+ // use the CAN for the password since that doesn't change
+ func_return = EPA_PACE_MSE_Set_AT(pace_version_info, 2);
+
+ // now get the nonce
+ uint8_t nonce[256] = {0};
+ uint8_t requested_size = (uint8_t)c->arg[0];
+ func_return = EPA_PACE_Get_Nonce(requested_size, nonce);
+ // check if the command succeeded
+ if (func_return < 0)
+ {
+ EPA_PACE_Collect_Nonce_Abort(ack, 4, func_return);
+ return;
+ }
+
+ // save received information
+ ack->arg[1] = func_return;
+ memcpy(ack->d.asBytes, nonce, func_return);
+
+ // all done, return
+ EPA_Finish();
+ UsbSendPacket((void *)ack, sizeof(UsbCommand));
+}
+
+//-----------------------------------------------------------------------------
+// Performs the "Get Nonce" step of the PACE protocol and saves the returned
+// nonce. The caller is responsible for allocating enough memory to store the
+// nonce. Note that the returned size might be less or than or greater than the
+// requested size!
+// Returns the actual size of the nonce on success or a less-than-zero error
+// code on failure.
+//-----------------------------------------------------------------------------
+int EPA_PACE_Get_Nonce(uint8_t requested_length, uint8_t *nonce)
+{
+ // build the APDU
+ uint8_t apdu[sizeof(apdu_general_authenticate_pace_get_nonce) + 1];
+ // copy the constant part
+ memcpy(apdu,
+ apdu_general_authenticate_pace_get_nonce,
+ sizeof(apdu_general_authenticate_pace_get_nonce));
+ // append Le (requested length + 2 due to tag/length taking 2 bytes) in RAPDU
+ apdu[sizeof(apdu_general_authenticate_pace_get_nonce)] = requested_length + 4;
+
+ // send it
+ uint8_t response_apdu[262];
+ int send_return = iso14_apdu(apdu,
+ sizeof(apdu),
+ response_apdu);
+ // check if the command succeeded
+ if (send_return < 6
+ || response_apdu[send_return - 4] != 0x90
+ || response_apdu[send_return - 3] != 0x00)
+ {
+ return -1;
+ }
+
+ // if there is no nonce in the RAPDU, return here
+ if (send_return < 10)
+ {
+ // no error
+ return 0;
+ }
+ // get the actual length of the nonce
+ uint8_t nonce_length = response_apdu[5];
+ if (nonce_length > send_return - 10)
+ {
+ nonce_length = send_return - 10;
+ }
+ // copy the nonce
+ memcpy(nonce, response_apdu + 6, nonce_length);
+
+ return nonce_length;
+}
+
+//-----------------------------------------------------------------------------
+// Initializes the PACE protocol by performing the "MSE: Set AT" step
+// Returns 0 on success or a non-zero error code on failure
+//-----------------------------------------------------------------------------
+int EPA_PACE_MSE_Set_AT(pace_version_info_t pace_version_info, uint8_t password)
+{
+ // create the MSE: Set AT APDU
+ uint8_t apdu[23];
+ // the minimum length (will be increased as more data is added)
+ size_t apdu_length = 20;
+ // copy the constant part
+ memcpy(apdu,
+ apdu_mse_set_at_start,
+ sizeof(apdu_mse_set_at_start));
+ // type: OID
+ apdu[5] = 0x80;
+ // length of the OID
+ apdu[6] = sizeof(pace_version_info.oid);
+ // copy the OID
+ memcpy(apdu + 7,
+ pace_version_info.oid,
+ sizeof(pace_version_info.oid));
+ // type: password
+ apdu[17] = 0x83;
+ // length: 1
+ apdu[18] = 1;
+ // password
+ apdu[19] = password;
+ // if standardized domain parameters are used, copy the ID
+ if (pace_version_info.parameter_id != 0) {
+ apdu_length += 3;
+ // type: domain parameter
+ apdu[20] = 0x84;
+ // length: 1
+ apdu[21] = 1;
+ // copy the parameter ID
+ apdu[22] = pace_version_info.parameter_id;
+ }
+ // now set Lc to the actual length
+ apdu[4] = apdu_length - 5;
+ // send it
+ uint8_t response_apdu[6];
+ int send_return = iso14_apdu(apdu,
+ apdu_length,
+ response_apdu);
+ // check if the command succeeded
+ if (send_return != 6
+ || response_apdu[send_return - 4] != 0x90
+ || response_apdu[send_return - 3] != 0x00)
+ {
+ return 1;
+ }
+ return 0;
+}
+
+//-----------------------------------------------------------------------------
+// Set up a communication channel (Card Select, PPS)
+// Returns 0 on success or a non-zero error code on failure
+//-----------------------------------------------------------------------------
+int EPA_Setup()
+{
+ // return code
+ int return_code = 0;
+ // card UID
+ uint8_t uid[8];
+ // card select information
+ iso14a_card_select_t card_select_info;
+ // power up the field
+ iso14443a_setup();
+
+ // select the card
+ return_code = iso14443a_select_card(uid, &card_select_info, NULL);
+ if (return_code != 1) {
+ return 1;
+ }
+
+ // send the PPS request
+ ReaderTransmit((uint8_t *)pps, sizeof(pps));
+ uint8_t pps_response[3];
+ return_code = ReaderReceive(pps_response);
+ if (return_code != 3 || pps_response[0] != 0xD0) {
+ return return_code == 0 ? 2 : return_code;
+ }
+
+ return 0;
+}
\ No newline at end of file
projects / proxmark3-svn / blobdiff