Juan Lang : crypt32: Implement CertVerifyCertificateChainPolicy for CERT_CHAIN_POLICY_SSL.
Module: wine Branch: master Commit: 9059892ec1da79567279aaeb96f46791718bc7a1 URL: http://source.winehq.org/git/wine.git/?a=commit;h=9059892ec1da79567279aaeb96... Author: Juan Lang <juan.lang(a)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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Alexandre Julliard