[PATCH] Improve hex parser robustness.

Max Max.Suraev at fairwaves.ru
Mon Jan 14 17:14:30 UTC 2013


---
 src/utils.c |   26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/utils.c b/src/utils.c
index c36979c..525bff1 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -73,7 +73,7 @@ uint8_t osmo_char2bcd(char c)
 	return c - 0x30;
 }
 
-/*! \brief Parse a string ocntaining hexadecimal digits
+/*! \brief Parse a string ocntaining hexadecimal digits, optionally prefixed with 0x
  *  \param[in] str string containing ASCII encoded hexadecimal digits
  *  \param[out] b output buffer
  *  \param[in] max_len maximum space in output buffer
@@ -81,10 +81,28 @@ uint8_t osmo_char2bcd(char c)
 int osmo_hexparse(const char *str, uint8_t *b, int max_len)
 
 {
-	int i, l, v;
+	int v;
+	size_t i, l = strlen(str);
+
+	if (l > 2) { /* remove 0x prefix if any */
+	    if ('0' == str[0] && 'x' == str[1]) {
+		l -= 2;
+		str += 2;
+	    }
+	}
+
+	if (l & 1) i = l + 1;
+	else i = l;
+	char hs[i]; /* enough space to store additional leading 0 if str length is odd */
+
+	if (l & 1) {
+	    memcpy(hs + 1, str, l);
+	    hs[0] = '0';
+	} else {
+	    memcpy(hs, str, l);
+	}
 
-	l = strlen(str);
-	if ((l&1) || ((l>>1) > max_len))
+	if ((l>>1) > max_len)
 		return -1;
 
 	memset(b, 0x00, max_len);
-- 
1.7.10.4


--------------040904080202060501050607--




More information about the baseband-devel mailing list