log_xxd_always(): use safer snprintf() instead of sprintf()

coverity: Event secure_coding: [VERY RISKY]. Using "sprintf" can cause a
buffer overflow when done incorrectly. Because sprintf() assumes an
arbitrarily long string, callers must be careful not to overflow the
actual space of the destination. Use snprintf() instead, or correct
precision specifiers.


git-svn-id: svn:https://anonscm.debian.org/svn/pcsclite/trunk/PCSC@5849 0ce88b0d-b2fd-0310-8134-9614164e65ea

src/debuglog.c

@@ -188,7 +188,8 @@ static void log_xxd_always(const int priority, const char *msg,
 
  for (i = 0; (i < len) && (c < debug_buf_end); ++i)
  {
- sprintf(c, "%02X ", buffer[i]);
+ /* 2 hex characters, 1 space, 1 NUL : total 4 characters */
+ snprintf(c, 4, "%02X ", buffer[i]);
  c += 3;
  }