Add PACE replay functionality

This function allows the user to specify APDUs which are sent to a card
supporting the PACE protocol. The response times are measured and
printed.
The code was pulled from the old Google Code repository (branch "epa")
and modified to fit into the new code base.

client/cmdhfepa.c

@@ -9,7 +9,7 @@
 //-----------------------------------------------------------------------------
 
 #include "util.h"
-//#include "proxusb.h"
+
 #include "proxmark3.h"
 #include "ui.h"
 #include "cmdparser.h"
@@ -29,9 +29,9 @@ int CmdHFEPACollectPACENonces(const char *Cmd)
 	unsigned int n = 0;
 	// delay between requests
 	unsigned int d = 0;
-	
+
 	sscanf(Cmd, "%u %u %u", &m, &n, &d);
-	
+
 	// values are expected to be > 0
 	m = m > 0 ? m : 1;
 	n = n > 0 ? n : 1;
@@ -44,7 +44,7 @@ int CmdHFEPACollectPACENonces(const char *Cmd)
 		UsbCommand c = {CMD_EPA_PACE_COLLECT_NONCE, {(int)m, 0, 0}};
 		SendCommand(&c);
 		UsbCommand resp;
-    
+
 		WaitForResponse(CMD_ACK,&resp);
 
 		// check if command failed
@@ -68,13 +68,123 @@ int CmdHFEPACollectPACENonces(const char *Cmd)
 	return 1;
 }
 
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////The commands lie below here/////////////////////////////////////////////////////////////////////////////////////////
+
+// perform the PACE protocol by replaying APDUs
+int CmdHFEPAPACEReplay(const char *Cmd)
+{
+	// the 4 APDUs which are replayed + their lengths
+	uint8_t msesa_apdu[41], gn_apdu[8], map_apdu[75];
+	uint8_t pka_apdu[75], ma_apdu[18], apdu_lengths[5] = {0};
+	// pointers to the arrays to be able to iterate
+	uint8_t *apdus[] = {msesa_apdu, gn_apdu, map_apdu, pka_apdu, ma_apdu};
+
+	// usage message
+	static const char const *usage_msg =
+		"Please specify 5 APDUs separated by spaces. "
+		"Example:\n preplay 0022C1A4 1068000000 1086000002 1234ABCDEF 1A2B3C4D";
+
+	// Proxmark response
+	UsbCommand resp;
+
+	int skip = 0, skip_add = 0, scan_return = 0;
+	// for each APDU
+	for (int i = 0; i < sizeof(apdu_lengths); i++) {
+		// scan to next space or end of string
+		while (Cmd[skip] != ' ' && Cmd[skip] != '\0') {
+			// convert
+			scan_return = sscanf(Cmd + skip, "%2X%n",
+			                     (unsigned int *) (apdus[i] + apdu_lengths[i]),
+			                     &skip_add);
+			if (scan_return < 1) {
+				PrintAndLog((char *)usage_msg);
+				PrintAndLog("Not enough APDUs! Try again!");
+				return 0;
+			}
+			skip += skip_add;
+            apdu_lengths[i]++;
+		}
+
+		// break on EOF
+		if (Cmd[skip] == '\0') {
+			if (i < sizeof(apdu_lengths) - 1) {
+
+				PrintAndLog((char *)usage_msg);
+				return 0;
+			}
+			break;
+		}
+		// skip the space
+		skip++;
+	}
+
+	// transfer the APDUs to the Proxmark
+	UsbCommand usb_cmd;
+	usb_cmd.cmd = CMD_EPA_PACE_REPLAY;
+	for (int i = 0; i < sizeof(apdu_lengths); i++) {
+		// APDU number
+		usb_cmd.arg[0] = i + 1;
+		// transfer the APDU in several parts if necessary
+		for (int j = 0; j * sizeof(usb_cmd.d.asBytes) < apdu_lengths[i]; j++) {
+			// offset into the APDU
+			usb_cmd.arg[1] = j * sizeof(usb_cmd.d.asBytes);
+			// amount of data in this packet
+			int packet_length = apdu_lengths[i] - (j * sizeof(usb_cmd.d.asBytes));
+			if (packet_length > sizeof(usb_cmd.d.asBytes)) {
+				packet_length = sizeof(usb_cmd.d.asBytes);
+			}
+			usb_cmd.arg[2] = packet_length;
+
+			memcpy(usb_cmd.d.asBytes, // + (j * sizeof(usb_cmd.d.asBytes)),
+			       apdus[i] + (j * sizeof(usb_cmd.d.asBytes)),
+			       packet_length);
+			SendCommand(&usb_cmd);
+			WaitForResponse(CMD_ACK, &resp);
+			if (resp.arg[0] != 0) {
+				PrintAndLog("Transfer of APDU #%d Part %d failed!", i, j);
+				return 0;
+			}
+		}
+	}
+
+	// now perform the replay
+	usb_cmd.arg[0] = 0;
+	SendCommand(&usb_cmd);
+	WaitForResponse(CMD_ACK, &resp);
+	if (resp.arg[0] != 0) {
+		PrintAndLog("\nPACE replay failed in step %u!", (uint32_t)resp.arg[0]);
+		PrintAndLog("Measured times:");
+		PrintAndLog("MSE Set AT: %u us", resp.d.asDwords[0]);
+		PrintAndLog("GA Get Nonce: %u us", resp.d.asDwords[1]);
+		PrintAndLog("GA Map Nonce: %u us", resp.d.asDwords[2]);
+		PrintAndLog("GA Perform Key Agreement: %u us", resp.d.asDwords[3]);
+		PrintAndLog("GA Mutual Authenticate: %u us", resp.d.asDwords[4]);
+	} else {
+		PrintAndLog("PACE replay successfull!");
+		PrintAndLog("MSE Set AT: %u us", resp.d.asDwords[0]);
+		PrintAndLog("GA Get Nonce: %u us", resp.d.asDwords[1]);
+		PrintAndLog("GA Map Nonce: %u us", resp.d.asDwords[2]);
+		PrintAndLog("GA Perform Key Agreement: %u us", resp.d.asDwords[3]);
+		PrintAndLog("GA Mutual Authenticate: %u us", resp.d.asDwords[4]);
+	}
+
+
+	return 1;
+}
+
+////////////////////////////////The new commands lie above here/////////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
 // UI-related stuff
 
-static const command_t CommandTable[] = 
+static const command_t CommandTable[] =
 {
   {"help",    CmdHelp,                   1, "This help"},
   {"cnonces", CmdHFEPACollectPACENonces, 0,
               "<m> <n> <d> Acquire n>0 encrypted PACE nonces of size m>0 with d sec pauses"},
+  {"preplay", CmdHFEPAPACEReplay,        0,
+   "<mse> <get> <map> <pka> <ma> Perform PACE protocol by replaying given APDUs"},
   {NULL, NULL, 0, NULL}
 };
 
@@ -92,4 +202,4 @@ int CmdHFEPA(const char *Cmd)
 	// parse
   CmdsParse(CommandTable, Cmd);
   return 0;
-}
+}