Add strict checks to hex to binary conversions.

[oweals/tinc.git] / lib / utils.c

diff --git a/lib/utils.c b/lib/utils.c
index 405097bbe3d01c592a05147c6df36422c614af65..3b221f59f0ef731f62b0369314de5964bdf855fd 100644 (file)
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -32,11 +32,13 @@ static int charhex2bin(char c) {
                return toupper(c) - 'A' + 10;
 }
 
-
-void hex2bin(char *src, char *dst, int length) {
-       int i;
-       for(i = 0; i < length; i++)
+bool hex2bin(char *src, char *dst, int length) {
+       for(int i = 0; i < length; i++) {
+               if(!isxdigit(src[i * 2]) || !isxdigit(src[i * 2 + 1]))
+                       return false;
                dst[i] = charhex2bin(src[i * 2]) * 16 + charhex2bin(src[i * 2 + 1]);
+       }
+       return true;
 }
 
 void bin2hex(char *src, char *dst, int length) {