blob: 716bdd5c4ec1ce4ca272b5cf2fb187b6731feeb0 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/cert/x509_certificate.h"
#include <CommonCrypto/CommonDigest.h>
#include <CoreServices/CoreServices.h>
#include <Security/Security.h>
#include <vector>
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/mac/mac_logging.h"
#include "base/mac/scoped_cftyperef.h"
#include "base/memory/singleton.h"
#include "base/pickle.h"
#include "base/sha1.h"
#include "base/strings/string_piece.h"
#include "base/strings/sys_string_conversions.h"
#include "base/synchronization/lock.h"
#include "crypto/cssm_init.h"
#include "crypto/mac_security_services_lock.h"
#include "net/cert/x509_util_mac.h"
using base::ScopedCFTypeRef;
using base::Time;
namespace net {
namespace {
void GetCertDistinguishedName(
const x509_util::CSSMCachedCertificate& cached_cert,
const CSSM_OID* oid,
CertPrincipal* result) {
x509_util::CSSMFieldValue distinguished_name;
OSStatus status = cached_cert.GetField(oid, &distinguished_name);
if (status || !distinguished_name.field())
return;
result->ParseDistinguishedName(distinguished_name.field()->Data,
distinguished_name.field()->Length);
}
bool IsCertIssuerInEncodedList(X509Certificate::OSCertHandle cert_handle,
const std::vector<std::string>& issuers) {
x509_util::CSSMCachedCertificate cached_cert;
if (cached_cert.Init(cert_handle) != CSSM_OK)
return false;
x509_util::CSSMFieldValue distinguished_name;
OSStatus status = cached_cert.GetField(&CSSMOID_X509V1IssuerNameStd,
&distinguished_name);
if (status || !distinguished_name.field())
return false;
base::StringPiece name_piece(
reinterpret_cast<const char*>(distinguished_name.field()->Data),
static_cast<size_t>(distinguished_name.field()->Length));
for (std::vector<std::string>::const_iterator it = issuers.begin();
it != issuers.end(); ++it) {
base::StringPiece issuer_piece(*it);
if (name_piece == issuer_piece)
return true;
}
return false;
}
void GetCertDateForOID(const x509_util::CSSMCachedCertificate& cached_cert,
const CSSM_OID* oid,
Time* result) {
*result = Time::Time();
x509_util::CSSMFieldValue field;
OSStatus status = cached_cert.GetField(oid, &field);
if (status)
return;
const CSSM_X509_TIME* x509_time = field.GetAs<CSSM_X509_TIME>();
if (x509_time->timeType != BER_TAG_UTC_TIME &&
x509_time->timeType != BER_TAG_GENERALIZED_TIME) {
LOG(ERROR) << "Unsupported date/time format "
<< x509_time->timeType;
return;
}
base::StringPiece time_string(
reinterpret_cast<const char*>(x509_time->time.Data),
x509_time->time.Length);
CertDateFormat format = x509_time->timeType == BER_TAG_UTC_TIME ?
CERT_DATE_FORMAT_UTC_TIME : CERT_DATE_FORMAT_GENERALIZED_TIME;
if (!ParseCertificateDate(time_string, format, result))
LOG(ERROR) << "Invalid certificate date/time " << time_string;
}
std::string GetCertSerialNumber(
const x509_util::CSSMCachedCertificate& cached_cert) {
x509_util::CSSMFieldValue serial_number;
OSStatus status = cached_cert.GetField(&CSSMOID_X509V1SerialNumber,
&serial_number);
if (status || !serial_number.field())
return std::string();
return std::string(
reinterpret_cast<const char*>(serial_number.field()->Data),
serial_number.field()->Length);
}
// Returns true if |purpose| is listed as allowed in |usage|. This
// function also considers the "Any" purpose. If the attribute is
// present and empty, we return false.
bool ExtendedKeyUsageAllows(const CE_ExtendedKeyUsage* usage,
const CSSM_OID* purpose) {
for (unsigned p = 0; p < usage->numPurposes; ++p) {
if (CSSMOIDEqual(&usage->purposes[p], purpose))
return true;
if (CSSMOIDEqual(&usage->purposes[p], &CSSMOID_ExtendedKeyUsageAny))
return true;
}
return false;
}
// Test that a given |cert_handle| is actually a valid X.509 certificate, and
// return true if it is.
//
// On OS X, SecCertificateCreateFromData() does not return any errors if
// called with invalid data, as long as data is present. The actual decoding
// of the certificate does not happen until an API that requires a CSSM
// handle is called. While SecCertificateGetCLHandle is the most likely
// candidate, as it performs the parsing, it does not check whether the
// parsing was actually successful. Instead, SecCertificateGetSubject is
// used (supported since 10.3), as a means to check that the certificate
// parsed as a valid X.509 certificate.
bool IsValidOSCertHandle(SecCertificateRef cert_handle) {
const CSSM_X509_NAME* sanity_check = NULL;
OSStatus status = SecCertificateGetSubject(cert_handle, &sanity_check);
return status == noErr && sanity_check;
}
// Parses |data| of length |length|, attempting to decode it as the specified
// |format|. If |data| is in the specified format, any certificates contained
// within are stored into |output|.
void AddCertificatesFromBytes(const char* data, size_t length,
SecExternalFormat format,
X509Certificate::OSCertHandles* output) {
SecExternalFormat input_format = format;
ScopedCFTypeRef<CFDataRef> local_data(CFDataCreateWithBytesNoCopy(
kCFAllocatorDefault, reinterpret_cast<const UInt8*>(data), length,
kCFAllocatorNull));
CFArrayRef items = NULL;
OSStatus status;
{
base::AutoLock lock(crypto::GetMacSecurityServicesLock());
status = SecKeychainItemImport(local_data, NULL, &input_format,
NULL, 0, NULL, NULL, &items);
}
if (status) {
OSSTATUS_DLOG(WARNING, status)
<< "Unable to import items from data of length " << length;
return;
}
ScopedCFTypeRef<CFArrayRef> scoped_items(items);
CFTypeID cert_type_id = SecCertificateGetTypeID();
for (CFIndex i = 0; i < CFArrayGetCount(items); ++i) {
SecKeychainItemRef item = reinterpret_cast<SecKeychainItemRef>(
const_cast<void*>(CFArrayGetValueAtIndex(items, i)));
// While inputFormat implies only certificates will be imported, if/when
// other formats (eg: PKCS#12) are supported, this may also include
// private keys or other items types, so filter appropriately.
if (CFGetTypeID(item) == cert_type_id) {
SecCertificateRef cert = reinterpret_cast<SecCertificateRef>(item);
// OS X ignores |input_format| if it detects that |local_data| is PEM
// encoded, attempting to decode data based on internal rules for PEM
// block headers. If a PKCS#7 blob is encoded with a PEM block of
// CERTIFICATE, OS X 10.5 will return a single, invalid certificate
// based on the decoded data. If this happens, the certificate should
// not be included in |output|. Because |output| is empty,
// CreateCertificateListfromBytes will use PEMTokenizer to decode the
// data. When called again with the decoded data, OS X will honor
// |input_format|, causing decode to succeed. On OS X 10.6, the data
// is properly decoded as a PKCS#7, whether PEM or not, which avoids
// the need to fallback to internal decoding.
if (IsValidOSCertHandle(cert)) {
CFRetain(cert);
output->push_back(cert);
}
}
}
}
} // namespace
void X509Certificate::Initialize() {
x509_util::CSSMCachedCertificate cached_cert;
if (cached_cert.Init(cert_handle_) == CSSM_OK) {
GetCertDistinguishedName(cached_cert, &CSSMOID_X509V1SubjectNameStd,
&subject_);
GetCertDistinguishedName(cached_cert, &CSSMOID_X509V1IssuerNameStd,
&issuer_);
GetCertDateForOID(cached_cert, &CSSMOID_X509V1ValidityNotBefore,
&valid_start_);
GetCertDateForOID(cached_cert, &CSSMOID_X509V1ValidityNotAfter,
&valid_expiry_);
serial_number_ = GetCertSerialNumber(cached_cert);
}
fingerprint_ = CalculateFingerprint(cert_handle_);
ca_fingerprint_ = CalculateCAFingerprint(intermediate_ca_certs_);
}
bool X509Certificate::IsIssuedByEncoded(
const std::vector<std::string>& valid_issuers) {
if (IsCertIssuerInEncodedList(cert_handle_, valid_issuers))
return true;
for (OSCertHandles::iterator it = intermediate_ca_certs_.begin();
it != intermediate_ca_certs_.end(); ++it) {
if (IsCertIssuerInEncodedList(*it, valid_issuers))
return true;
}
return false;
}
void X509Certificate::GetSubjectAltName(
std::vector<std::string>* dns_names,
std::vector<std::string>* ip_addrs) const {
if (dns_names)
dns_names->clear();
if (ip_addrs)
ip_addrs->clear();
x509_util::CSSMCachedCertificate cached_cert;
OSStatus status = cached_cert.Init(cert_handle_);
if (status)
return;
x509_util::CSSMFieldValue subject_alt_name;
status = cached_cert.GetField(&CSSMOID_SubjectAltName, &subject_alt_name);
if (status || !subject_alt_name.field())
return;
const CSSM_X509_EXTENSION* cssm_ext =
subject_alt_name.GetAs<CSSM_X509_EXTENSION>();
if (!cssm_ext || !cssm_ext->value.parsedValue)
return;
const CE_GeneralNames* alt_name =
reinterpret_cast<const CE_GeneralNames*>(cssm_ext->value.parsedValue);
for (size_t name = 0; name < alt_name->numNames; ++name) {
const CE_GeneralName& name_struct = alt_name->generalName[name];
const CSSM_DATA& name_data = name_struct.name;
// DNSName and IPAddress are encoded as IA5String and OCTET STRINGs
// respectively, both of which can be byte copied from
// CSSM_DATA::data into the appropriate output vector.
if (dns_names && name_struct.nameType == GNT_DNSName) {
dns_names->push_back(std::string(
reinterpret_cast<const char*>(name_data.Data),
name_data.Length));
} else if (ip_addrs && name_struct.nameType == GNT_IPAddress) {
ip_addrs->push_back(std::string(
reinterpret_cast<const char*>(name_data.Data),
name_data.Length));
}
}
}
// static
bool X509Certificate::GetDEREncoded(X509Certificate::OSCertHandle cert_handle,
std::string* encoded) {
CSSM_DATA der_data;
if (!cert_handle || SecCertificateGetData(cert_handle, &der_data) != noErr)
return false;
encoded->assign(reinterpret_cast<char*>(der_data.Data),
der_data.Length);
return true;
}
// static
bool X509Certificate::IsSameOSCert(X509Certificate::OSCertHandle a,
X509Certificate::OSCertHandle b) {
DCHECK(a && b);
if (a == b)
return true;
if (CFEqual(a, b))
return true;
CSSM_DATA a_data, b_data;
return SecCertificateGetData(a, &a_data) == noErr &&
SecCertificateGetData(b, &b_data) == noErr &&
a_data.Length == b_data.Length &&
memcmp(a_data.Data, b_data.Data, a_data.Length) == 0;
}
// static
X509Certificate::OSCertHandle X509Certificate::CreateOSCertHandleFromBytes(
const char* data, int length) {
CSSM_DATA cert_data;
cert_data.Data = const_cast<uint8*>(reinterpret_cast<const uint8*>(data));
cert_data.Length = length;
OSCertHandle cert_handle = NULL;
OSStatus status = SecCertificateCreateFromData(&cert_data,
CSSM_CERT_X_509v3,
CSSM_CERT_ENCODING_DER,
&cert_handle);
if (status != noErr)
return NULL;
if (!IsValidOSCertHandle(cert_handle)) {
CFRelease(cert_handle);
return NULL;
}
return cert_handle;
}
// static
X509Certificate::OSCertHandles X509Certificate::CreateOSCertHandlesFromBytes(
const char* data, int length, Format format) {
OSCertHandles results;
switch (format) {
case FORMAT_SINGLE_CERTIFICATE: {
OSCertHandle handle = CreateOSCertHandleFromBytes(data, length);
if (handle)
results.push_back(handle);
break;
}
case FORMAT_PKCS7:
AddCertificatesFromBytes(data, length, kSecFormatPKCS7, &results);
break;
default:
NOTREACHED() << "Certificate format " << format << " unimplemented";
break;
}
return results;
}
// static
X509Certificate::OSCertHandle X509Certificate::DupOSCertHandle(
OSCertHandle handle) {
if (!handle)
return NULL;
return reinterpret_cast<OSCertHandle>(const_cast<void*>(CFRetain(handle)));
}
// static
void X509Certificate::FreeOSCertHandle(OSCertHandle cert_handle) {
if (cert_handle)
CFRelease(cert_handle);
}
// static
SHA1HashValue X509Certificate::CalculateFingerprint(
OSCertHandle cert) {
SHA1HashValue sha1;
memset(sha1.data, 0, sizeof(sha1.data));
CSSM_DATA cert_data;
OSStatus status = SecCertificateGetData(cert, &cert_data);
if (status)
return sha1;
DCHECK(cert_data.Data);
DCHECK_NE(cert_data.Length, 0U);
CC_SHA1(cert_data.Data, cert_data.Length, sha1.data);
return sha1;
}
// static
SHA1HashValue X509Certificate::CalculateCAFingerprint(
const OSCertHandles& intermediates) {
SHA1HashValue sha1;
memset(sha1.data, 0, sizeof(sha1.data));
// The CC_SHA(3cc) man page says all CC_SHA1_xxx routines return 1, so
// we don't check their return values.
CC_SHA1_CTX sha1_ctx;
CC_SHA1_Init(&sha1_ctx);
CSSM_DATA cert_data;
for (size_t i = 0; i < intermediates.size(); ++i) {
OSStatus status = SecCertificateGetData(intermediates[i], &cert_data);
if (status)
return sha1;
CC_SHA1_Update(&sha1_ctx, cert_data.Data, cert_data.Length);
}
CC_SHA1_Final(sha1.data, &sha1_ctx);
return sha1;
}
bool X509Certificate::SupportsSSLClientAuth() const {
x509_util::CSSMCachedCertificate cached_cert;
OSStatus status = cached_cert.Init(cert_handle_);
if (status)
return false;
// RFC5280 says to take the intersection of the two extensions.
//
// Our underlying crypto libraries don't expose
// ClientCertificateType, so for now we will not support fixed
// Diffie-Hellman mechanisms. For rsa_sign, we need the
// digitalSignature bit.
//
// In particular, if a key has the nonRepudiation bit and not the
// digitalSignature one, we will not offer it to the user.
x509_util::CSSMFieldValue key_usage;
status = cached_cert.GetField(&CSSMOID_KeyUsage, &key_usage);
if (status == CSSM_OK && key_usage.field()) {
const CSSM_X509_EXTENSION* ext = key_usage.GetAs<CSSM_X509_EXTENSION>();
const CE_KeyUsage* key_usage_value =
reinterpret_cast<const CE_KeyUsage*>(ext->value.parsedValue);
if (!((*key_usage_value) & CE_KU_DigitalSignature))
return false;
}
status = cached_cert.GetField(&CSSMOID_ExtendedKeyUsage, &key_usage);
if (status == CSSM_OK && key_usage.field()) {
const CSSM_X509_EXTENSION* ext = key_usage.GetAs<CSSM_X509_EXTENSION>();
const CE_ExtendedKeyUsage* ext_key_usage =
reinterpret_cast<const CE_ExtendedKeyUsage*>(ext->value.parsedValue);
if (!ExtendedKeyUsageAllows(ext_key_usage, &CSSMOID_ClientAuth))
return false;
}
return true;
}
CFArrayRef X509Certificate::CreateOSCertChainForCert() const {
CFMutableArrayRef cert_list =
CFArrayCreateMutable(kCFAllocatorDefault, 0,
&kCFTypeArrayCallBacks);
if (!cert_list)
return NULL;
CFArrayAppendValue(cert_list, os_cert_handle());
for (size_t i = 0; i < intermediate_ca_certs_.size(); ++i)
CFArrayAppendValue(cert_list, intermediate_ca_certs_[i]);
return cert_list;
}
// static
X509Certificate::OSCertHandle
X509Certificate::ReadOSCertHandleFromPickle(PickleIterator* pickle_iter) {
const char* data;
int length;
if (!pickle_iter->ReadData(&data, &length))
return NULL;
return CreateOSCertHandleFromBytes(data, length);
}
// static
bool X509Certificate::WriteOSCertHandleToPickle(OSCertHandle cert_handle,
Pickle* pickle) {
CSSM_DATA cert_data;
OSStatus status = SecCertificateGetData(cert_handle, &cert_data);
if (status)
return false;
return pickle->WriteData(reinterpret_cast<char*>(cert_data.Data),
cert_data.Length);
}
// static
void X509Certificate::GetPublicKeyInfo(OSCertHandle cert_handle,
size_t* size_bits,
PublicKeyType* type) {
// Since we might fail, set the output parameters to default values first.
*type = kPublicKeyTypeUnknown;
*size_bits = 0;
SecKeyRef key;
OSStatus status = SecCertificateCopyPublicKey(cert_handle, &key);
if (status) {
NOTREACHED() << "SecCertificateCopyPublicKey failed: " << status;
return;
}
ScopedCFTypeRef<SecKeyRef> scoped_key(key);
const CSSM_KEY* cssm_key;
status = SecKeyGetCSSMKey(key, &cssm_key);
if (status) {
NOTREACHED() << "SecKeyGetCSSMKey failed: " << status;
return;
}
*size_bits = cssm_key->KeyHeader.LogicalKeySizeInBits;
switch (cssm_key->KeyHeader.AlgorithmId) {
case CSSM_ALGID_RSA:
*type = kPublicKeyTypeRSA;
break;
case CSSM_ALGID_DSA:
*type = kPublicKeyTypeDSA;
break;
case CSSM_ALGID_ECDSA:
*type = kPublicKeyTypeECDSA;
break;
case CSSM_ALGID_DH:
*type = kPublicKeyTypeDH;
break;
default:
*type = kPublicKeyTypeUnknown;
*size_bits = 0;
break;
}
}
} // namespace net