From 58a6240af96ad6f699b97da2ea13bef943ee4431 Mon Sep 17 00:00:00 2001
From: John Jones <jmjatlanta@gmail.com>
Date: Thu, 13 Jul 2017 18:29:02 -0500
Subject: [PATCH] Fixed bug on odd byte ip addresses

IP addresses that when converted to an integer ended up as a string with
an odd number of bytes would result in a memory read into invalid
memory. Zero filled the text string representation of the bytes to avoid
this issue.
---
 test_multiaddr.h | 21 +++++++++++++++++++++
 testing.c        |  6 ++++--
 varhexutils.c    | 22 +++++++++++++++++-----
 3 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/test_multiaddr.h b/test_multiaddr.h
index f98eff6..d8b7096 100644
--- a/test_multiaddr.h
+++ b/test_multiaddr.h
@@ -3,6 +3,27 @@
 #include "multiaddr/multiaddr.h"
 #include "multiaddr/varhexutils.h"
 
+int test_new_like_libp2p() {
+	int retVal = 0;
+	char* ip = "10.211.55.2";
+	int port = 4001;
+	char str[strlen(ip) + 50];
+	sprintf(str, "/ip4/%s/tcp/%d/", ip, port);
+	struct MultiAddress* ma_string = multiaddress_new_from_string(str);
+	// convert to binary
+	struct MultiAddress* ma_binary = multiaddress_new_from_bytes(ma_string->bytes, ma_string->bsize);
+	if (strcmp(ma_string->string, ma_binary->string) != 0) {
+		fprintf(stderr, "%s does not equal %s\n", ma_string->string, ma_binary->string);
+		goto exit;
+	}
+
+	retVal = 1;
+	exit:
+	multiaddress_free(ma_string);
+	multiaddress_free(ma_binary);
+	return retVal;
+}
+
 int test_new_from_string() {
 	struct MultiAddress* a = multiaddress_new_from_string("/ip4/127.0.0.1/tcp/8080/");
 	printf("Number of Bytes: %lu, Bytes: ", a->bsize);
diff --git a/testing.c b/testing.c
index 35e5997..dc86df9 100644
--- a/testing.c
+++ b/testing.c
@@ -10,7 +10,8 @@ const char* names[] = {
 		"test_multiaddr_utils",
 		"test_multiaddr_peer_id",
 		"test_multiaddr_get_peer_id",
-		"test_multiaddr_bytes"
+		"test_multiaddr_bytes",
+		"test_new_like_libp2p"
 };
 
 int (*funcs[])(void) = {
@@ -21,7 +22,8 @@ int (*funcs[])(void) = {
 		test_multiaddr_utils,
 		test_multiaddr_peer_id,
 		test_multiaddr_get_peer_id,
-		test_multiaddr_bytes
+		test_multiaddr_bytes,
+		test_new_like_libp2p
 };
 
 int testit(const char* name, int (*func)(void)) {
diff --git a/varhexutils.c b/varhexutils.c
index cec9c08..dab4cfa 100644
--- a/varhexutils.c
+++ b/varhexutils.c
@@ -51,14 +51,26 @@ uint32_t * Varint_To_Num_32(uint8_t TON32INPUT[60]) //VARINT TO UINT32_t
 	uvarint_decode32(TON32INPUT, 60, &varintdecode_032);
 	return &varintdecode_032;
 }
-//
+/**
+ * Converts a 64 bit integer into a hex string
+ * @param int2hex the 64 bit integer
+ * @returns a hex representation as a string (leading zero if necessary)
+ */
 char * Int_To_Hex(uint64_t int2hex) //VAR[binformat] TO HEX
 {
-	static char int2hex_result[800]="\0";
-	memset(int2hex_result,0,sizeof(int2hex_result));
-	sprintf (int2hex_result, "%02lX", int2hex);
-	return int2hex_result;
+	static char result[50];
+	memset(result, 0, 50);
+	sprintf(result, "%02lX", int2hex);
+	int slen = strlen(result);
+	if (slen % 2 != 0) {
+		for(int i = slen; i >= 0; --i) {
+			result[i+1] = result[i];
+		}
+		result[0] = '0';
+	}
+	return result;
 }
+
 uint64_t Hex_To_Int(char * hax)
 {
 	char * hex = NULL;