Juan Lang : crypt32: Implement CertVerifyCertificateChainPolicy for CERT_CHAIN_POLICY_SSL.
Alexandre Julliard
julliard at winehq.org
Thu Oct 29 11:20:36 CDT 2009
Module: wine
Branch: master
Commit: 9059892ec1da79567279aaeb96f46791718bc7a1
URL: http://source.winehq.org/git/wine.git/?a=commit;h=9059892ec1da79567279aaeb96f46791718bc7a1
Author: Juan Lang <juan.lang at gmail.com>
Date: Wed Oct 28 09:17:30 2009 -0700
crypt32: Implement CertVerifyCertificateChainPolicy for CERT_CHAIN_POLICY_SSL.
---
dlls/crypt32/chain.c | 231 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 231 insertions(+), 0 deletions(-)
diff --git a/dlls/crypt32/chain.c b/dlls/crypt32/chain.c
index e8f9de3..8972463 100644
--- a/dlls/crypt32/chain.c
+++ b/dlls/crypt32/chain.c
@@ -2117,6 +2117,234 @@ static BOOL WINAPI verify_basic_constraints_policy(LPCSTR szPolicyOID,
return TRUE;
}
+static inline PCERT_EXTENSION get_subject_alt_name_ext(PCCERT_CONTEXT cert)
+{
+ PCERT_EXTENSION ext;
+
+ ext = CertFindExtension(szOID_SUBJECT_ALT_NAME2,
+ cert->pCertInfo->cExtension, cert->pCertInfo->rgExtension);
+ if (!ext)
+ ext = CertFindExtension(szOID_SUBJECT_ALT_NAME,
+ cert->pCertInfo->cExtension, cert->pCertInfo->rgExtension);
+ return ext;
+}
+
+static BOOL match_dns_to_subject_alt_name(PCERT_EXTENSION ext,
+ LPCWSTR server_name)
+{
+ BOOL matches = FALSE;
+ CERT_ALT_NAME_INFO *subjectName;
+ DWORD size;
+
+ TRACE_(chain)("%s\n", debugstr_w(server_name));
+ /* FIXME: This can be spoofed by the embedded NULL vulnerability. The
+ * returned CERT_ALT_NAME_INFO doesn't have a way to indicate the
+ * encoded length of a name, so a certificate issued to
+ * winehq.org\0badsite.com will get treated as having been issued to
+ * winehq.org.
+ */
+ if (CryptDecodeObjectEx(X509_ASN_ENCODING, X509_ALTERNATE_NAME,
+ ext->Value.pbData, ext->Value.cbData,
+ CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_NOCOPY_FLAG, NULL,
+ &subjectName, &size))
+ {
+ DWORD i;
+ BOOL found = FALSE;
+
+ for (i = 0; !found && i < subjectName->cAltEntry; i++)
+ {
+ if (subjectName->rgAltEntry[i].dwAltNameChoice ==
+ CERT_ALT_NAME_DNS_NAME)
+ {
+ TRACE_(chain)("dNSName: %s\n", debugstr_w(
+ subjectName->rgAltEntry[i].u.pwszDNSName));
+ found = TRUE;
+ if (!strcmpiW(server_name,
+ subjectName->rgAltEntry[i].u.pwszDNSName))
+ matches = TRUE;
+ }
+ }
+ LocalFree(subjectName);
+ }
+ return matches;
+}
+
+static BOOL find_matching_domain_component(CERT_NAME_INFO *name,
+ LPCWSTR component)
+{
+ BOOL matches = FALSE;
+ DWORD i, j;
+
+ for (i = 0; !matches && i < name->cRDN; i++)
+ for (j = 0; j < name->rgRDN[i].cRDNAttr; j++)
+ if (!strcmp(szOID_DOMAIN_COMPONENT,
+ name->rgRDN[i].rgRDNAttr[j].pszObjId))
+ {
+ PCERT_RDN_ATTR attr;
+
+ attr = &name->rgRDN[i].rgRDNAttr[j];
+ /* Compare with memicmpW rather than strcmpiW in order to avoid
+ * a match with a string with an embedded NULL. The component
+ * must match one domain component attribute's entire string
+ * value with a case-insensitive match.
+ */
+ matches = !memicmpW(component, (LPWSTR)attr->Value.pbData,
+ attr->Value.cbData / sizeof(WCHAR));
+ }
+ return matches;
+}
+
+static BOOL match_dns_to_subject_dn(PCCERT_CONTEXT cert, LPCWSTR server_name)
+{
+ BOOL matches = FALSE;
+ CERT_NAME_INFO *name;
+ DWORD size;
+
+ TRACE_(chain)("%s\n", debugstr_w(server_name));
+ if (CryptDecodeObjectEx(X509_ASN_ENCODING, X509_UNICODE_NAME,
+ cert->pCertInfo->Subject.pbData, cert->pCertInfo->Subject.cbData,
+ CRYPT_DECODE_ALLOC_FLAG | CRYPT_DECODE_NOCOPY_FLAG, NULL,
+ &name, &size))
+ {
+ /* If the subject distinguished name contains any name components,
+ * make sure all of them are present.
+ */
+ if (CertFindRDNAttr(szOID_DOMAIN_COMPONENT, name))
+ {
+ LPCWSTR ptr = server_name;
+
+ matches = TRUE;
+ do {
+ LPCWSTR dot = strchrW(ptr, '.'), end;
+ /* 254 is the maximum DNS label length, see RFC 1035 */
+ WCHAR component[255];
+ DWORD len;
+
+ end = dot ? dot : ptr + strlenW(ptr);
+ len = end - ptr;
+ if (len >= sizeof(component) / sizeof(component[0]))
+ {
+ WARN_(chain)("domain component %s too long\n",
+ debugstr_wn(ptr, len));
+ matches = FALSE;
+ }
+ else
+ {
+ memcpy(component, ptr, len * sizeof(WCHAR));
+ component[len] = 0;
+ matches = find_matching_domain_component(name, component);
+ }
+ ptr = dot ? dot + 1 : end;
+ } while (matches && ptr && *ptr);
+ }
+ else
+ {
+ 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.
+ */
+ 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));
+ }
+ }
+ LocalFree(name);
+ }
+ return matches;
+}
+
+static BOOL WINAPI verify_ssl_policy(LPCSTR szPolicyOID,
+ PCCERT_CHAIN_CONTEXT pChainContext, PCERT_CHAIN_POLICY_PARA pPolicyPara,
+ PCERT_CHAIN_POLICY_STATUS pPolicyStatus)
+{
+ pPolicyStatus->lChainIndex = pPolicyStatus->lElementIndex = -1;
+ if (pChainContext->TrustStatus.dwErrorStatus &
+ CERT_TRUST_IS_NOT_SIGNATURE_VALID)
+ {
+ pPolicyStatus->dwError = TRUST_E_CERT_SIGNATURE;
+ find_element_with_error(pChainContext,
+ CERT_TRUST_IS_NOT_SIGNATURE_VALID, &pPolicyStatus->lChainIndex,
+ &pPolicyStatus->lElementIndex);
+ }
+ else if (pChainContext->TrustStatus.dwErrorStatus &
+ CERT_TRUST_IS_UNTRUSTED_ROOT)
+ {
+ pPolicyStatus->dwError = CERT_E_UNTRUSTEDROOT;
+ find_element_with_error(pChainContext,
+ CERT_TRUST_IS_UNTRUSTED_ROOT, &pPolicyStatus->lChainIndex,
+ &pPolicyStatus->lElementIndex);
+ }
+ else if (pChainContext->TrustStatus.dwErrorStatus & CERT_TRUST_IS_CYCLIC)
+ {
+ pPolicyStatus->dwError = CERT_E_UNTRUSTEDROOT;
+ find_element_with_error(pChainContext,
+ CERT_TRUST_IS_CYCLIC, &pPolicyStatus->lChainIndex,
+ &pPolicyStatus->lElementIndex);
+ /* For a cyclic chain, which element is a cycle isn't meaningful */
+ pPolicyStatus->lElementIndex = -1;
+ }
+ else if (pChainContext->TrustStatus.dwErrorStatus &
+ CERT_TRUST_IS_NOT_TIME_VALID)
+ {
+ pPolicyStatus->dwError = CERT_E_EXPIRED;
+ find_element_with_error(pChainContext,
+ CERT_TRUST_IS_NOT_TIME_VALID, &pPolicyStatus->lChainIndex,
+ &pPolicyStatus->lElementIndex);
+ }
+ else
+ pPolicyStatus->dwError = NO_ERROR;
+ /* We only need bother checking whether the name in the end certificate
+ * matches if the chain is otherwise okay.
+ */
+ if (!pPolicyStatus->dwError && pPolicyPara &&
+ pPolicyPara->cbSize >= sizeof(CERT_CHAIN_POLICY_PARA))
+ {
+ HTTPSPolicyCallbackData *sslPara = pPolicyPara->pvExtraPolicyPara;
+
+ if (sslPara && sslPara->u.cbSize >= sizeof(HTTPSPolicyCallbackData))
+ {
+ if (sslPara->dwAuthType == AUTHTYPE_SERVER &&
+ sslPara->pwszServerName)
+ {
+ PCCERT_CONTEXT cert;
+ PCERT_EXTENSION altNameExt;
+ BOOL matches;
+
+ cert = pChainContext->rgpChain[0]->rgpElement[0]->pCertContext;
+ altNameExt = get_subject_alt_name_ext(cert);
+ /* If the alternate name extension exists, the name it contains
+ * is bound to the certificate, so make sure the name matches
+ * it. Otherwise, look for the server name in the subject
+ * distinguished name. RFC5280, section 4.2.1.6:
+ * "Whenever such identities are to be bound into a
+ * certificate, the subject alternative name (or issuer
+ * alternative name) extension MUST be used; however, a DNS
+ * name MAY also be represented in the subject field using the
+ * domainComponent attribute."
+ */
+ if (altNameExt)
+ matches = match_dns_to_subject_alt_name(altNameExt,
+ sslPara->pwszServerName);
+ else
+ matches = match_dns_to_subject_dn(cert,
+ sslPara->pwszServerName);
+ if (!matches)
+ {
+ pPolicyStatus->dwError = CERT_E_CN_NO_MATCH;
+ pPolicyStatus->lChainIndex = 0;
+ pPolicyStatus->lElementIndex = 0;
+ }
+ }
+ }
+ }
+ return TRUE;
+}
+
static BYTE msPubKey1[] = {
0x30,0x82,0x01,0x0a,0x02,0x82,0x01,0x01,0x00,0xdf,0x08,0xba,0xe3,0x3f,0x6e,
0x64,0x9b,0xf5,0x89,0xaf,0x28,0x96,0x4a,0x07,0x8f,0x1b,0x2e,0x8b,0x3e,0x1d,
@@ -2257,6 +2485,9 @@ BOOL WINAPI CertVerifyCertificateChainPolicy(LPCSTR szPolicyOID,
case LOWORD(CERT_CHAIN_POLICY_AUTHENTICODE):
verifyPolicy = verify_authenticode_policy;
break;
+ case LOWORD(CERT_CHAIN_POLICY_SSL):
+ verifyPolicy = verify_ssl_policy;
+ break;
case LOWORD(CERT_CHAIN_POLICY_BASIC_CONSTRAINTS):
verifyPolicy = verify_basic_constraints_policy;
break;
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