crypt32: Implement matching a certificate with a wildcard in its name.

This commit is contained in:
Juan Lang 2009-11-11 17:45:49 -08:00 committed by Alexandre Julliard
parent e740672647
commit b91d0c8bde
2 changed files with 131 additions and 9 deletions

View file

@ -2418,6 +2418,134 @@ static BOOL find_matching_domain_component(CERT_NAME_INFO *name,
return matches;
}
static BOOL match_domain_component(LPCWSTR allowed_component, DWORD allowed_len,
LPCWSTR server_component, DWORD server_len, BOOL allow_wildcards,
BOOL *see_wildcard)
{
LPCWSTR allowed_ptr, server_ptr;
BOOL matches = TRUE;
*see_wildcard = FALSE;
if (server_len < allowed_len)
{
WARN_(chain)("domain component %s too short for %s\n",
debugstr_wn(server_component, server_len),
debugstr_wn(allowed_component, allowed_len));
/* A domain component can't contain a wildcard character, so a domain
* component shorter than the allowed string can't produce a match.
*/
return FALSE;
}
for (allowed_ptr = allowed_component, server_ptr = server_component;
matches && allowed_ptr - allowed_component < allowed_len;
allowed_ptr++, server_ptr++)
{
if (*allowed_ptr == '*')
{
if (allowed_ptr - allowed_component < allowed_len - 1)
{
WARN_(chain)("non-wildcard characters after wildcard not supported\n");
matches = FALSE;
}
else if (!allow_wildcards)
{
WARN_(chain)("wildcard after non-wildcard component\n");
matches = FALSE;
}
else
{
/* the preceding characters must have matched, so the rest of
* the component also matches.
*/
*see_wildcard = TRUE;
break;
}
}
matches = tolowerW(*allowed_ptr) == tolowerW(*server_ptr);
}
if (matches && server_ptr - server_component < server_len)
{
/* If there are unmatched characters in the server domain component,
* the server domain only matches if the allowed string ended in a '*'.
*/
matches = *allowed_ptr == '*';
}
return matches;
}
static BOOL match_common_name(LPCWSTR server_name, PCERT_RDN_ATTR nameAttr)
{
LPCWSTR allowed = (LPCWSTR)nameAttr->Value.pbData;
LPCWSTR allowed_component = allowed;
DWORD allowed_len = nameAttr->Value.cbData / sizeof(WCHAR);
LPCWSTR server_component = server_name;
DWORD server_len = strlenW(server_name);
BOOL matches = TRUE, allow_wildcards = TRUE;
TRACE_(chain)("CN = %s\n", debugstr_wn(allowed_component, allowed_len));
/* From RFC 2818 (HTTP over TLS), section 3.1:
* "Names may contain the wildcard character * which is considered to match
* any single domain name component or component fragment. E.g.,
* *.a.com matches foo.a.com but not bar.foo.a.com. f*.com matches foo.com
* but not bar.com."
*
* And from RFC 2595 (Using TLS with IMAP, POP3 and ACAP), section 2.4:
* "A "*" wildcard character MAY be used as the left-most name component in
* the certificate. For example, *.example.com would match a.example.com,
* foo.example.com, etc. but would not match example.com."
*
* There are other protocols which use TLS, and none of them is
* authoritative. This accepts certificates in common usage, e.g.
* *.domain.com matches www.domain.com but not domain.com, and
* www*.domain.com matches www1.domain.com but not mail.domain.com.
*/
do {
LPCWSTR allowed_dot, server_dot;
allowed_dot = memchrW(allowed_component, '.',
allowed_len - (allowed_component - allowed));
server_dot = memchrW(server_component, '.',
server_len - (server_component - server_name));
/* The number of components must match */
if ((!allowed_dot && server_dot) || (allowed_dot && !server_dot))
{
if (!allowed_dot)
WARN_(chain)("%s: too many components for CN=%s\n",
debugstr_w(server_name), debugstr_wn(allowed, allowed_len));
else
WARN_(chain)("%s: not enough components for CN=%s\n",
debugstr_w(server_name), debugstr_wn(allowed, allowed_len));
matches = FALSE;
}
else
{
LPCWSTR allowed_end, server_end;
BOOL has_wildcard;
allowed_end = allowed_dot ? allowed_dot : allowed + allowed_len;
server_end = server_dot ? server_dot : server_name + server_len;
matches = match_domain_component(allowed_component,
allowed_end - allowed_component, server_component,
server_end - server_component, allow_wildcards, &has_wildcard);
/* Once a non-wildcard component is seen, no wildcard components
* may follow
*/
if (!has_wildcard)
allow_wildcards = FALSE;
if (matches)
{
allowed_component = allowed_dot ? allowed_dot + 1 : allowed_end;
server_component = server_dot ? server_dot + 1 : server_end;
}
}
} while (matches && allowed_component &&
allowed_component - allowed < allowed_len &&
server_component && server_component - server_name < server_len);
TRACE_(chain)("returning %d\n", matches);
return matches;
}
static BOOL match_dns_to_subject_dn(PCCERT_CONTEXT cert, LPCWSTR server_name)
{
BOOL matches = FALSE;
@ -2466,16 +2594,10 @@ static BOOL match_dns_to_subject_dn(PCCERT_CONTEXT cert, LPCWSTR server_name)
PCERT_RDN_ATTR attr;
/* If the certificate isn't using a DN attribute in the name, make
* make sure the common name matches. Again, use memicmpW rather
* than strcmpiW in order to avoid being fooled by an embedded NULL.
* make sure the common name matches.
*/
if ((attr = CertFindRDNAttr(szOID_COMMON_NAME, name)))
{
TRACE_(chain)("CN = %s\n", debugstr_w(
(LPWSTR)attr->Value.pbData));
matches = !memicmpW(server_name, (LPWSTR)attr->Value.pbData,
attr->Value.cbData / sizeof(WCHAR));
}
matches = match_common_name(server_name, attr);
}
LocalFree(name);
}

View file

@ -3392,7 +3392,7 @@ static const ChainPolicyCheck iTunesPolicyCheckWithoutMatchingName = {
static const ChainPolicyCheck opensslPolicyCheckWithMatchingName = {
{ sizeof(opensslChain) / sizeof(opensslChain[0]), opensslChain },
{ 0, 0, -1, -1, NULL}, NULL, TODO_ERROR
{ 0, 0, -1, -1, NULL}, NULL, 0
};
static const ChainPolicyCheck opensslPolicyCheckWithoutMatchingName = {