From 607bef7ffd2be0403b907f7c720e531c5dbe7161 Mon Sep 17 00:00:00 2001
From: merlokk <807634+merlokk@users.noreply.github.com>
Date: Thu, 10 Jan 2019 16:22:32 +0200
Subject: [PATCH] AC Response Format1

---
 client/emv/cmdemv.c | 53 ++++++++++++++++++++++++++++++++++++++++++---
 client/emv/tlv.c    | 15 +++++++++++--
 client/emv/tlv.h    |  1 +
 3 files changed, 64 insertions(+), 5 deletions(-)

diff --git a/client/emv/cmdemv.c b/client/emv/cmdemv.c
index 2274f3d69..a30c22aec 100644
--- a/client/emv/cmdemv.c
+++ b/client/emv/cmdemv.c
@@ -38,6 +38,9 @@ void ParamLoadDefaults(struct tlvdb *tlvRoot) {
 	TLV_ADD(0x9F6A, "\x01\x02\x03\x04");
 	//9F66:(Terminal Transaction Qualifiers (TTQ)) len:4
 	TLV_ADD(0x9F66, "\x26\x00\x00\x00"); // qVSDC
+	//95:(Terminal Verification Results) len:5
+	// all OK TVR
+	TLV_ADD(0x95,   "\x00\x00\x00\x00\x00");
 }
 
 void PrintChannel(EMVCommandChannel channel) {
@@ -685,6 +688,50 @@ void ProcessGPOResponseFormat1(struct tlvdb *tlvRoot, uint8_t *buf, size_t len,
 	}
 }
 
+void ProcessACResponseFormat1(struct tlvdb *tlvRoot, uint8_t *buf, size_t len, bool decodeTLV) {
+	if (buf[0] == 0x80) {
+		if (decodeTLV){
+			PrintAndLog("GPO response format1:");
+			TLVPrintFromBuffer(buf, len);
+		}
+		
+		uint8_t elmlen = len - 2; // wo 0x80XX
+		
+		if (len < 4 + 2 || (elmlen - 2) % 4 || elmlen != buf[1]) {
+			PrintAndLogEx(ERR, "GPO response format1 parsing error. length=%d", len);
+		} else {
+			struct tlvdb *tlvElm = NULL;
+			if (decodeTLV)
+				PrintAndLog("\n------------ Format1 decoded ------------");
+			
+			// CID (Cryptogram Information Data)
+			tlvdb_change_or_add_node_ex(tlvRoot, 0x9f27, 1, &buf[2], &tlvElm);
+			if (decodeTLV)
+				TLVPrintFromTLV(tlvElm);
+
+			// ATC (Application Transaction Counter)
+			tlvdb_change_or_add_node_ex(tlvRoot, 0x9f36, 2, &buf[3], &tlvElm);		
+			if (decodeTLV)
+				TLVPrintFromTLV(tlvElm);
+
+			// AC (Application Cryptogram)
+			tlvdb_change_or_add_node_ex(tlvRoot, 0x9f26, min(8, elmlen - 3), &buf[5], &tlvElm);		
+			if (decodeTLV)
+				TLVPrintFromTLV(tlvElm);
+
+			// IAD (Issuer Application Data) - optional
+			if (len > 11 + 2) {
+				tlvdb_change_or_add_node_ex(tlvRoot, 0x9f10, elmlen - 11, &buf[13], &tlvElm);		
+				if (decodeTLV)
+					TLVPrintFromTLV(tlvElm);
+			}			
+		}		
+	} else {
+		if (decodeTLV)
+			TLVPrintFromBuffer(buf, len);
+	}
+}
+
 int CmdEMVExec(const char *cmd) {
 	uint8_t buf[APDU_RES_LEN] = {0};
 	size_t len = 0;
@@ -1151,9 +1198,9 @@ int CmdEMVExec(const char *cmd) {
 			PrintAndLogEx(NORMAL, "AC1 error(%d): %4x. Exit...", res, sw);
 			dreturn(7);
 		}
-		
-		if (decodeTLV)
-			TLVPrintFromBuffer(buf, len);
+
+		// process Format1 (0x80) anf print Format2 (0x77)
+		ProcessACResponseFormat1(tlvRoot, buf, len, decodeTLV);
 		
 		PrintAndLogEx(NORMAL, "\n* * Processing online request\n");
 
diff --git a/client/emv/tlv.c b/client/emv/tlv.c
index 013e9735a..9722c9311 100644
--- a/client/emv/tlv.c
+++ b/client/emv/tlv.c
@@ -359,12 +359,15 @@ void tlvdb_add(struct tlvdb *tlvdb, struct tlvdb *other)
 	tlvdb->next = other;
 }
 
-void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value)
+void tlvdb_change_or_add_node_ex(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value, struct tlvdb **tlvdb_elm)
 {
 	struct tlvdb *telm = tlvdb_find_full(tlvdb, tag);
 	if (telm == NULL) {
 		// new tlv element
-		tlvdb_add(tlvdb, tlvdb_fixed(tag, len, value));
+		struct tlvdb *elm = tlvdb_fixed(tag, len, value);
+		tlvdb_add(tlvdb, elm);
+		if (tlvdb_elm)
+			*tlvdb_elm = elm;
 	} else {
 		// the same tlv structure
 		if (telm->tag.tag == tag && telm->tag.len == len && !memcmp(telm->tag.value, value, len))
@@ -400,11 +403,19 @@ void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, co
 		// free old element with childrens
 		telm->next = NULL;
 		tlvdb_free(telm);
+		
+		if (tlvdb_elm)
+			*tlvdb_elm = tnewelm;
 	}
 	
 	return;
 }
 
+void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value)
+{
+	tlvdb_change_or_add_node_ex(tlvdb, tag, len, value, NULL);
+}
+
 void tlvdb_visit(const struct tlvdb *tlvdb, tlv_cb cb, void *data, int level)
 {
 	struct tlvdb *next = NULL;
diff --git a/client/emv/tlv.h b/client/emv/tlv.h
index d2a55525f..1f52e440b 100644
--- a/client/emv/tlv.h
+++ b/client/emv/tlv.h
@@ -50,6 +50,7 @@ struct tlvdb *tlvdb_find_path(struct tlvdb *tlvdb, tlv_tag_t tag[]);
 
 void tlvdb_add(struct tlvdb *tlvdb, struct tlvdb *other);
 void tlvdb_change_or_add_node(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value);
+void tlvdb_change_or_add_node_ex(struct tlvdb *tlvdb, tlv_tag_t tag, size_t len, const unsigned char *value, struct tlvdb **tlvdb_elm);
 
 void tlvdb_visit(const struct tlvdb *tlvdb, tlv_cb cb, void *data, int level);
 const struct tlv *tlvdb_get(const struct tlvdb *tlvdb, tlv_tag_t tag, const struct tlv *prev);