From 56c9bcc03a6d4c42e3aea902eb5d7d3c7bfb8651 Mon Sep 17 00:00:00 2001
From: merlokk <807634+merlokk@users.noreply.github.com>
Date: Tue, 19 Feb 2019 21:15:54 +0200
Subject: [PATCH] added IAD decoding and some improvements

---
 client/emv/cmdemv.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 5 deletions(-)

diff --git a/client/emv/cmdemv.c b/client/emv/cmdemv.c
index d0015ac38..477062d38 100644
--- a/client/emv/cmdemv.c
+++ b/client/emv/cmdemv.c
@@ -1212,16 +1212,79 @@ int CmdEMVExec(const char *cmd) {
 		if ((CID & EMVAC_AC_MASK) == EMVAC_ARQC)	PrintAndLogEx(INFO, "AC1 result: ARQC (Online authorisation requested)");
 		if ((CID & EMVAC_AC_MASK) == EMVAC_AC_MASK)	PrintAndLogEx(INFO, "AC1 result: RFU");
 
-		PrintAndLogEx(NORMAL, "\n* * Processing online request\n");
+		// decode Issuer Application Data (IAD)
+		uint8_t CryptoVersion = 0;
+		const struct tlv *IAD = tlvdb_get(tlvRoot, 0x9f10, NULL);
+		if (IAD && (IAD->len > 1)) {
+			PrintAndLogEx(NORMAL, "\n* * Issuer Application Data (IAD):");
+			uint8_t VDDlen = IAD->value[0]; // Visa discretionary data length
+			uint8_t IDDlen = 0;             // Issuer discretionary data length
+			PrintAndLogEx(NORMAL, "IAD length: %d", IAD->len);
+			PrintAndLogEx(NORMAL, "VDDlen: %d", VDDlen);
+			if (VDDlen < IAD->len - 1) 
+				IDDlen = IAD->value[VDDlen + 1];
+			PrintAndLogEx(NORMAL, "IDDlen: %d", IDDlen);
+						
+			uint8_t DerivKeyIndex = IAD->value[1];
+			CryptoVersion = IAD->value[2];
+
+			PrintAndLogEx(NORMAL, "CryptoVersion: %d", CryptoVersion);
+			PrintAndLogEx(NORMAL, "DerivKeyIndex: %d", DerivKeyIndex);
+
+			// Card Verification Results (CVR) decode
+			if ((VDDlen - 2) > 0) {
+				uint8_t CVRlen = IAD->value[3];
+				if (CVRlen == (VDDlen - 2 - 1)) {
+					PrintAndLogEx(NORMAL, "CVR length: %d", CVRlen);
+					PrintAndLogEx(NORMAL, "CVR: %s", sprint_hex(&IAD->value[4], CVRlen));
+				} else {
+					PrintAndLogEx(NORMAL, "Wrong CVR length! CVR: %s", sprint_hex(&IAD->value[3], VDDlen - 2));
+				}
+			}
+			if (IDDlen)
+				PrintAndLogEx(NORMAL, "IDD: %s", sprint_hex(&IAD->value[VDDlen + 1], IDDlen));		
+		} else {
+			PrintAndLogEx(NORMAL, "Issuer Application Data (IAD) not found.");
+		}
+		
+		PrintAndLogEx(NORMAL, "\n* * Processing online request");
 
 		// authorization response code from acquirer
 		const char HostResponse[] = "00"; // 0x3030
-		PrintAndLogEx(NORMAL, "* * Host Response: `%s`", HostResponse);
-		tlvdb_change_or_add_node(tlvRoot, 0x8a, sizeof(HostResponse) - 1, (const unsigned char *)HostResponse);		
+		size_t HostResponseLen = sizeof(HostResponse) - 1;
+		PrintAndLogEx(NORMAL, "Host Response: `%s`", HostResponse);
+		tlvdb_change_or_add_node(tlvRoot, 0x8a, HostResponseLen, (const unsigned char *)HostResponse);		
 		
+		if (CryptoVersion == 10) {
+			PrintAndLogEx(NORMAL, "\n* * Generate ARPC");
+			
+			// Application Cryptogram (AC)
+			const struct tlv *AC = tlvdb_get(tlvRoot, 0x9f26, NULL);
+			if (AC && (AC->len > 0)) {
+				PrintAndLogEx(NORMAL, "AC: %s", sprint_hex(AC->value, AC->len));
+
+				size_t rawARPClen = AC->len;
+				uint8_t rawARPC[rawARPClen];
+				memcpy(rawARPC, AC->value, AC->len);
+				for (int i = 0; (i < HostResponseLen) && (i < rawARPClen); i++)
+					rawARPC[i] ^= HostResponse[i];
+				PrintAndLogEx(NORMAL, "raw ARPC: %s", sprint_hex(rawARPC, rawARPClen));
+				
+				// here must be calculation of ARPC, but we dont know a bank keys.
+				PrintAndLogEx(NORMAL, "ARPC: n/a");
+				
+			} else {
+				PrintAndLogEx(NORMAL, "Application Cryptogram (AC) not found.");
+			}
+
+			// here must be external authenticate, but we dont know ARPC
+			
+		}
+		
+
 		// needs to send AC2 command (res == ARQC)
 		if ((CID & 0xc0) == 0x80) {
-			PrintAndLogEx(NORMAL, "* * Calc CDOL2");
+			PrintAndLogEx(NORMAL, "\n* * Calc CDOL2");
 			struct tlv *cdol2_data_tlv = dol_process(tlvdb_get(tlvRoot, 0x8d, NULL), tlvRoot, 0x01); // 0x01 - dummy tag
 			if (!cdol2_data_tlv) {
 				PrintAndLogEx(WARNING, "Error: can't create CDOL2 TLV.");
@@ -1230,9 +1293,11 @@ int CmdEMVExec(const char *cmd) {
 			
 			PrintAndLogEx(NORMAL, "CDOL2 data[%d]: %s", cdol2_data_tlv->len, sprint_hex(cdol2_data_tlv->value, cdol2_data_tlv->len));
 			
-			PrintAndLogEx(NORMAL, "* * AC2");
+			//PrintAndLogEx(NORMAL, "* * AC2");
 			
 			
+			// here must be AC2, but we dont make external authenticate (
+		
 /*			// AC2
 			PRINT_INDENT(level);
 			if ((CID & EMVAC_AC2_MASK) == EMVAC_AAC2)	fprintf(f, "\tAC2: AAC (Transaction declined)\n");