+ /*
+ * Locate first and only legal wildcard, either at the start
+ * or end of a non-IDNA first and not final label.
+ */
+ if (p[i] == '*')
+ {
+ int atstart = (state & LABEL_START);
+ int atend = (i == len - 1 || p[i+i] == '.');
+ /*
+ * At most one wildcard per pattern.
+ * No wildcards in IDNA labels.
+ * No wildcards after the first label.
+ */
+ if (star != NULL || (state & LABEL_IDNA) != 0 || dots)
+ return NULL;
+ /* Only full-label '*.example.com' wildcards? */
+ if ((flags & X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)
+ && (!atstart || !atend))
+ return NULL;
+ /* No 'foo*bar' wildcards */
+ if (!atstart && !atend)
+ return NULL;
+ star = &p[i];
+ state &= ~LABEL_START;
+ }
+ else if ((state & LABEL_START) != 0)
+ {
+ /*
+ * At the start of a label, skip any "xn--" and
+ * remain in the LABEL_START state, but set the
+ * IDNA label state
+ */
+ if ((state & LABEL_IDNA) == 0 && len - i >= 4
+ && strncasecmp((char *)&p[i], "xn--", 4) == 0)
+ {
+ i += 3;
+ state |= LABEL_IDNA;
+ continue;
+ }
+ /* Labels must start with a letter or digit */
+ state &= ~LABEL_START;
+ if (('a' <= p[i] && p[i] <= 'z')
+ || ('A' <= p[i] && p[i] <= 'Z')
+ || ('0' <= p[i] && p[i] <= '9'))
+ continue;
+ return NULL;
+ }
+ else if (('a' <= p[i] && p[i] <= 'z')
+ || ('A' <= p[i] && p[i] <= 'Z')
+ || ('0' <= p[i] && p[i] <= '9'))
+ {
+ state &= LABEL_IDNA;
+ continue;
+ }
+ else if (p[i] == '.')
+ {
+ if (state & (LABEL_HYPHEN | LABEL_START))
+ return NULL;
+ state = LABEL_START;
+ ++dots;
+ }
+ else if (p[i] == '-')
+ {
+ if (state & LABEL_HYPHEN)
+ return NULL;
+ state |= LABEL_HYPHEN;
+ }
+ else
+ return NULL;