const unsigned char *subject, size_t subject_len,
unsigned int flags);
+/* Skip pattern prefix to match "wildcard" subject */
+static void skip_prefix(const unsigned char **p, size_t *plen,
+ const unsigned char *subject, size_t subject_len,
+ unsigned int flags)
+ {
+ const unsigned char *pattern = *p;
+ size_t pattern_len = *plen;
+
+ /*
+ * If subject starts with a leading '.' followed by more octets, and
+ * pattern is longer, compare just an equal-length suffix with the
+ * full subject (starting at the '.'), provided the prefix contains
+ * no NULs. (We check again that subject starts with '.' and
+ * contains at least one subsequent character, just in case the
+ * internal _X509_CHECK_FLAG_DOT_SUBDOMAINS flag was erroneously
+ * set by the user).
+ */
+ if ((flags & _X509_CHECK_FLAG_DOT_SUBDOMAINS) == 0 ||
+ subject_len <= 1 || subject[0] != '.')
+ return;
+
+ while (pattern_len > subject_len && *pattern)
+ {
+ if ((flags & X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS) &&
+ *pattern == '.')
+ break;
+ ++pattern;
+ --pattern_len;
+ }
+
+ /* Skip if entire prefix acceptable */
+ if (pattern_len == subject_len)
+ {
+ *p = pattern;
+ *plen = pattern_len;
+ }
+ }
+
/* Compare while ASCII ignoring case. */
static int equal_nocase(const unsigned char *pattern, size_t pattern_len,
const unsigned char *subject, size_t subject_len,
- unsigned int unused_flags)
+ unsigned int flags)
{
+ skip_prefix(&pattern, &pattern_len, subject, subject_len, flags);
if (pattern_len != subject_len)
return 0;
while (pattern_len)
/* Compare using memcmp. */
static int equal_case(const unsigned char *pattern, size_t pattern_len,
const unsigned char *subject, size_t subject_len,
- unsigned int unused_flags)
+ unsigned int flags)
{
- /* The pattern must not contain NUL characters. */
- if (memchr(pattern, '\0', pattern_len) != NULL)
- return 0;
+ skip_prefix(&pattern, &pattern_len, subject, subject_len, flags);
if (pattern_len != subject_len)
return 0;
return !memcmp(pattern, subject, pattern_len);
const unsigned char *subject, size_t subject_len,
unsigned int flags)
{
- const unsigned char *star = valid_star(pattern, pattern_len, flags);
+ const unsigned char *star = NULL;
+
+ /*
+ * Subject names starting with '.' can only match a wildcard pattern
+ * via a subject sub-domain pattern suffix match.
+ */
+ if (!(subject_len > 1 && subject[0] == '.'))
+ star = valid_star(pattern, pattern_len, flags);
if (star == NULL)
return equal_nocase(pattern, pattern_len,
subject, subject_len, flags);
else if (check_type == GEN_DNS)
{
cnid = NID_commonName;
+ /* Implicit client-side DNS sub-domain pattern */
+ if (chklen > 1 && chk[0] == '.')
+ flags |= _X509_CHECK_FLAG_DOT_SUBDOMAINS;
alt_type = V_ASN1_IA5STRING;
if (flags & X509_CHECK_FLAG_NO_WILDCARDS)
equal = equal_nocase;
"*@example.com", "test@*.example.com", "example.com", "www.example.com",
"test.www.example.com", "*.example.com", "*.www.example.com",
"test.*.example.com", "www.*.com",
+ ".www.example.com", "*www.example.com",
"example.net", "xn--rger-koa.example.com",
"a.example.com", "b.example.com",
"postmaster@example.com", "Postmaster@example.com",
"set CN: host: [*.example.com] matches [www.example.com]",
"set CN: host: [*.example.com] matches [xn--rger-koa.example.com]",
"set CN: host: [*.www.example.com] matches [test.www.example.com]",
+ "set CN: host: [*.www.example.com] matches [.www.example.com]",
+ "set CN: host: [*www.example.com] matches [www.example.com]",
+ "set CN: host: [test.www.example.com] matches [.www.example.com]",
+ "set CN: host-no-wildcards: [*.www.example.com] matches [.www.example.com]",
+ "set CN: host-no-wildcards: [test.www.example.com] matches [.www.example.com]",
"set emailAddress: email: [postmaster@example.com] does not match [Postmaster@example.com]",
"set emailAddress: email: [postmaster@EXAMPLE.COM] does not match [Postmaster@example.com]",
"set emailAddress: email: [Postmaster@example.com] does not match [postmaster@example.com]",
"set dnsName: host: [*.example.com] matches [b.example.com]",
"set dnsName: host: [*.example.com] matches [xn--rger-koa.example.com]",
"set dnsName: host: [*.www.example.com] matches [test.www.example.com]",
+ "set dnsName: host-no-wildcards: [*.www.example.com] matches [.www.example.com]",
+ "set dnsName: host-no-wildcards: [test.www.example.com] matches [.www.example.com]",
+ "set dnsName: host: [*.www.example.com] matches [.www.example.com]",
+ "set dnsName: host: [*www.example.com] matches [www.example.com]",
+ "set dnsName: host: [test.www.example.com] matches [.www.example.com]",
"set rfc822Name: email: [postmaster@example.com] does not match [Postmaster@example.com]",
"set rfc822Name: email: [Postmaster@example.com] does not match [postmaster@example.com]",
"set rfc822Name: email: [Postmaster@example.com] does not match [postmaster@EXAMPLE.COM]",
#define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0x4
/* Allow (non-partial) wildcards to match multiple labels. */
#define X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS 0x8
+/* Constraint verifier subdomain patterns to match a single labels. */
+#define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0x10
+/*
+ * Match reference identifiers starting with "." to any sub-domain.
+ * This is a non-public flag, turned on implicitly when the subject
+ * reference identity is a DNS name.
+ */
+#define _X509_CHECK_FLAG_DOT_SUBDOMAINS 0x8000
int X509_check_host(X509 *x, const unsigned char *chk, size_t chklen,
unsigned int flags);
host name, which must be encoded in the preferred name syntax
described in section 3.5 of RFC 1034. The B<namelen> argument must be
the number of characters in the name string or zero in which case the
-length is calculated with strlen(name).
+length is calculated with strlen(name). When B<name> starts with
+a dot (e.g ".example.com"), it will be matched by a certificate
+valid for any sub-domain of B<name>, (see also
+B<X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS> below).
X509_check_email() checks if the certificate matches the specified
email address. Only the mailbox syntax of RFC 822 is supported,
=item B<X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS>.
+=item B<X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS>.
+
=back
The B<X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT> flag causes the function
for "*" as wildcard pattern in labels that have a prefix or suffix,
such as: "www*" or "*www"; this only aplies to B<X509_check_host>.
-If set, B<X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS>, allows a "*"
-that constitutes the complete label of a DNS name (e.g.
-"*.example.com") to match more than one label in B<name>;
-this only applies to B<X509_check_host>.
+If set, B<X509_CHECK_FLAG_MULTI_LABEL_WILDCARDS> allows a "*" that
+constitutes the complete label of a DNS name (e.g. "*.example.com")
+to match more than one label in B<name>; this flag only applies
+to B<X509_check_host>.
+
+If set, B<X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS> restricts B<name>
+values which start with ".", that would otherwise match any sub-domain
+in the peer certificate, to only match direct child sub-domains.
+Thus, for instance, with this flag set a B<name> of ".example.com"
+would match a peer certificate with a DNS name of "www.example.com",
+but would not match a peer certificate with a DNS name of
+"www.sub.example.com"; this flag only applies to B<X509_check_host>.
=head1 RETURN VALUES