crypt32: Forbid minimum or maximum fields in name constraints.

This commit is contained in:
Juan Lang 2009-11-06 13:56:09 -08:00 committed by Alexandre Julliard
parent e7404ba24f
commit 9fe6be454f

View file

@ -728,6 +728,40 @@ static CERT_NAME_CONSTRAINTS_INFO *CRYPT_GetNameConstraints(CERT_INFO *cert)
return info;
}
static BOOL CRYPT_IsValidNameConstraint(const CERT_NAME_CONSTRAINTS_INFO *info)
{
DWORD i;
BOOL ret = TRUE;
/* Check that none of the constraints specifies a minimum or a maximum.
* See RFC 5280, section 4.2.1.10:
* "Within this profile, the minimum and maximum fields are not used with
* any name forms, thus, the minimum MUST be zero, and maximum MUST be
* absent. However, if an application encounters a critical name
* constraints extension that specifies other values for minimum or
* maximum for a name form that appears in a subsequent certificate, the
* application MUST either process these fields or reject the
* certificate."
* Since it gives no guidance as to how to process these fields, we
* reject any name constraint that contains them.
*/
for (i = 0; ret && i < info->cPermittedSubtree; i++)
if (info->rgPermittedSubtree[i].dwMinimum ||
info->rgPermittedSubtree[i].fMaximum)
{
TRACE_(chain)("found a minimum or maximum in permitted subtrees\n");
ret = FALSE;
}
for (i = 0; ret && i < info->cExcludedSubtree; i++)
if (info->rgExcludedSubtree[i].dwMinimum ||
info->rgExcludedSubtree[i].fMaximum)
{
TRACE_(chain)("found a minimum or maximum in excluded subtrees\n");
ret = FALSE;
}
return ret;
}
static void CRYPT_CheckChainNameConstraints(PCERT_SIMPLE_CHAIN chain)
{
int i, j;
@ -751,21 +785,27 @@ static void CRYPT_CheckChainNameConstraints(PCERT_SIMPLE_CHAIN chain)
if ((nameConstraints = CRYPT_GetNameConstraints(
chain->rgpElement[i]->pCertContext->pCertInfo)))
{
for (j = i - 1; j >= 0; j--)
if (!CRYPT_IsValidNameConstraint(nameConstraints))
chain->rgpElement[i]->TrustStatus.dwErrorStatus |=
CERT_TRUST_HAS_NOT_SUPPORTED_NAME_CONSTRAINT;
else
{
DWORD errorStatus = 0;
/* According to RFC 3280, self-signed certs don't have name
* constraints checked unless they're the end cert.
*/
if (j == 0 || !CRYPT_IsCertificateSelfSigned(
chain->rgpElement[j]->pCertContext))
for (j = i - 1; j >= 0; j--)
{
CRYPT_CheckNameConstraints(nameConstraints,
chain->rgpElement[i]->pCertContext->pCertInfo,
&errorStatus);
chain->rgpElement[i]->TrustStatus.dwErrorStatus |=
errorStatus;
DWORD errorStatus = 0;
/* According to RFC 3280, self-signed certs don't have name
* constraints checked unless they're the end cert.
*/
if (j == 0 || !CRYPT_IsCertificateSelfSigned(
chain->rgpElement[j]->pCertContext))
{
CRYPT_CheckNameConstraints(nameConstraints,
chain->rgpElement[i]->pCertContext->pCertInfo,
&errorStatus);
chain->rgpElement[i]->TrustStatus.dwErrorStatus |=
errorStatus;
}
}
}
LocalFree(nameConstraints);