Mypal/security/manager/ssl/SSLServerCertVerification.cpp

1196 lines
47 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// For connections that are not processed on the socket transport thread, we do
// NOT use the async logic described below. Instead, we authenticate the
// certificate on the thread that the connection's I/O happens on,
// synchronously. This allows us to do certificate verification for blocking
// (not non-blocking) sockets and sockets that have their I/O processed on a
// thread other than the socket transport service thread. Also, we DO NOT
// support blocking sockets on the socket transport service thread at all.
//
// During certificate authentication, we call CERT_PKIXVerifyCert or
// CERT_VerifyCert. These functions may make zero or more HTTP requests
// for OCSP responses, CRLs, intermediate certificates, etc. Our fetching logic
// for these requests processes them on the socket transport service thread.
//
// If the connection for which we are verifying the certificate is happening
// on the socket transport thread (the usually case, at least for HTTP), then
// if our cert auth hook were to call the CERT_*Verify* functions directly,
// there would be a deadlock: The CERT_*Verify* function would cause an event
// to be asynchronously posted to the socket transport thread, and then it
// would block the socket transport thread waiting to be notified of the HTTP
// response. However, the HTTP request would never actually be processed
// because the socket transport thread would be blocked and so it wouldn't be
// able process HTTP requests. (i.e. Deadlock.)
//
// Consequently, when we are asked to verify a certificate on the socket
// transport service thread, we must always call the CERT_*Verify* cert
// functions on another thread. To accomplish this, our auth cert hook
// dispatches a SSLServerCertVerificationJob to a pool of background threads,
// and then immediately returns SECWouldBlock to libssl. These jobs are where
// the CERT_*Verify* functions are actually called.
//
// When our auth cert hook returns SECWouldBlock, libssl will carry on the
// handshake while we validate the certificate. This will free up the socket
// transport thread so that HTTP requests--in particular, the OCSP/CRL/cert
// requests needed for cert verification as mentioned above--can be processed.
//
// Once the CERT_*Verify* function returns, the cert verification job
// dispatches a SSLServerCertVerificationResult to the socket transport thread;
// the SSLServerCertVerificationResult will notify libssl that the certificate
// authentication is complete. Once libssl is notified that the authentication
// is complete, it will continue the SSL handshake (if it hasn't already
// finished) and it will begin allowing us to send/receive data on the
// connection.
//
// Timeline of events (for connections managed by the socket transport service):
//
// * libssl calls SSLServerCertVerificationJob::Dispatch on the socket
// transport thread.
// * SSLServerCertVerificationJob::Dispatch queues a job
// (instance of SSLServerCertVerificationJob) to its background thread
// pool and returns.
// * One of the background threads calls CERT_*Verify*, which may enqueue
// some HTTP request(s) onto the socket transport thread, and then
// blocks that background thread waiting for the responses and/or timeouts
// or errors for those requests.
// * Once those HTTP responses have all come back or failed, the
// CERT_*Verify* function returns a result indicating that the validation
// succeeded or failed.
// * If the validation succeeded, then a SSLServerCertVerificationResult
// event is posted to the socket transport thread, and the cert
// verification thread becomes free to verify other certificates.
// * Otherwise, a CertErrorRunnable is posted to the socket transport thread
// and then to the main thread (blocking both, see CertErrorRunnable) to
// do cert override processing and bad cert listener notification. Then
// the cert verification thread becomes free to verify other certificates.
// * After processing cert overrides, the CertErrorRunnable will dispatch a
// SSLServerCertVerificationResult event to the socket transport thread to
// notify it of the result of the override processing; then it returns,
// freeing up the main thread.
// * The SSLServerCertVerificationResult event will either wake up the
// socket (using SSL_RestartHandshakeAfterServerCert) if validation
// succeeded or there was an error override, or it will set an error flag
// so that the next I/O operation on the socket will fail, causing the
// socket transport thread to close the connection.
//
// Cert override processing must happen on the main thread because it accesses
// the nsICertOverrideService, and that service must be accessed on the main
// thread because some extensions (Selenium, in particular) replace it with a
// Javascript implementation, and chrome JS must always be run on the main
// thread.
//
// SSLServerCertVerificationResult must be dispatched to the socket transport
// thread because we must only call SSL_* functions on the socket transport
// thread since they may do I/O, because many parts of nsNSSSocketInfo (the
// subclass of TransportSecurityInfo used when validating certificates during
// an SSL handshake) and the PSM NSS I/O layer are not thread-safe, and because
// we need the event to interrupt the PR_Poll that may waiting for I/O on the
// socket for which we are validating the cert.
#include "SSLServerCertVerification.h"
#include <cstring>
#include "BRNameMatchingPolicy.h"
#include "CertVerifier.h"
#include "CryptoTask.h"
#include "ExtendedValidation.h"
#include "NSSCertDBTrustDomain.h"
#include "PSMRunnable.h"
#include "ScopedNSSTypes.h"
#include "SharedCertVerifier.h"
#include "SharedSSLState.h"
#include "TransportSecurityInfo.h" // For RememberCertErrorsTable
#include "cert.h"
#include "mozilla/Assertions.h"
#include "mozilla/Casting.h"
#include "mozilla/Mutex.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Unused.h"
#include "mozilla/net/DNS.h"
#include "nsComponentManagerUtils.h"
#include "nsContentUtils.h"
#include "nsIBadCertListener2.h"
#include "nsICertOverrideService.h"
#include "nsISiteSecurityService.h"
#include "nsISocketProvider.h"
#include "nsIThreadPool.h"
#include "nsNSSCertificate.h"
#include "nsNSSComponent.h"
#include "nsNSSIOLayer.h"
#include "nsNSSShutDown.h"
#include "nsSSLStatus.h"
#include "nsServiceManagerUtils.h"
#include "nsURLHelper.h"
#include "nsXPCOMCIDInternal.h"
#include "pkix/pkix.h"
#include "pkix/pkixnss.h"
#include "secerr.h"
#include "secoidt.h"
#include "secport.h"
#include "ssl.h"
#include "sslerr.h"
extern mozilla::LazyLogModule gPIPNSSLog;
using namespace mozilla::pkix;
namespace mozilla { namespace psm {
namespace {
// do not use a nsCOMPtr to avoid static initializer/destructor
nsIThreadPool* gCertVerificationThreadPool = nullptr;
// We add a mutex to serialize PKCS11 database operations
Mutex* gSSLVerificationPK11Mutex = nullptr;
} // unnamed namespace
// Called when the socket transport thread starts, to initialize the SSL cert
// verification thread pool. By tying the thread pool startup/shutdown directly
// to the STS thread's lifetime, we ensure that they are *always* available for
// SSL connections and that there are no races during startup and especially
// shutdown. (Previously, we have had multiple problems with races in PSM
// background threads, and the race-prevention/shutdown logic used there is
// brittle. Since this service is critical to things like downloading updates,
// we take no chances.) Also, by doing things this way, we avoid the need for
// locks, since gCertVerificationThreadPool is only ever accessed on the socket
// transport thread.
void
InitializeSSLServerCertVerificationThreads()
{
gSSLVerificationPK11Mutex = new Mutex("SSLVerificationPK11Mutex");
// TODO: tuning, make parameters preferences
// XXX: instantiate nsThreadPool directly, to make this more bulletproof.
// Currently, the nsThreadPool.h header isn't exported for us to do so.
nsresult rv = CallCreateInstance(NS_THREADPOOL_CONTRACTID,
&gCertVerificationThreadPool);
if (NS_FAILED(rv)) {
NS_WARNING("Failed to create SSL cert verification threads.");
return;
}
(void) gCertVerificationThreadPool->SetIdleThreadLimit(5);
(void) gCertVerificationThreadPool->SetIdleThreadTimeout(30 * 1000);
(void) gCertVerificationThreadPool->SetThreadLimit(5);
(void) gCertVerificationThreadPool->SetName(NS_LITERAL_CSTRING("SSL Cert"));
}
// Called when the socket transport thread finishes, to destroy the thread
// pool. Since the socket transport service has stopped processing events, it
// will not attempt any more SSL I/O operations, so it is clearly safe to shut
// down the SSL cert verification infrastructure. Also, the STS will not
// dispatch many SSL verification result events at this point, so any pending
// cert verifications will (correctly) fail at the point they are dispatched.
//
// The other shutdown race condition that is possible is a race condition with
// shutdown of the nsNSSComponent service. We use the
// nsNSSShutdownPreventionLock where needed (not here) to prevent that.
void StopSSLServerCertVerificationThreads()
{
if (gCertVerificationThreadPool) {
gCertVerificationThreadPool->Shutdown();
NS_RELEASE(gCertVerificationThreadPool);
}
if (gSSLVerificationPK11Mutex) {
delete gSSLVerificationPK11Mutex;
gSSLVerificationPK11Mutex = nullptr;
}
}
namespace {
void
LogInvalidCertError(nsNSSSocketInfo* socketInfo,
PRErrorCode errorCode,
::mozilla::psm::SSLErrorMessageType errorMessageType)
{
nsString message;
socketInfo->GetErrorLogMessage(errorCode, errorMessageType, message);
if (!message.IsEmpty()) {
nsContentUtils::LogSimpleConsoleError(message, "SSL");
}
}
// Dispatched to the STS thread to notify the infoObject of the verification
// result.
//
// This will cause the PR_Poll in the STS thread to return, so things work
// correctly even if the STS thread is blocked polling (only) on the file
// descriptor that is waiting for this result.
class SSLServerCertVerificationResult : public Runnable
{
public:
NS_DECL_NSIRUNNABLE
SSLServerCertVerificationResult(nsNSSSocketInfo* infoObject,
PRErrorCode errorCode,
SSLErrorMessageType errorMessageType =
PlainErrorMessage);
void Dispatch();
private:
const RefPtr<nsNSSSocketInfo> mInfoObject;
public:
const PRErrorCode mErrorCode;
const SSLErrorMessageType mErrorMessageType;
};
class CertErrorRunnable : public SyncRunnableBase
{
public:
CertErrorRunnable(const void* fdForLogging,
nsIX509Cert* cert,
nsNSSSocketInfo* infoObject,
PRErrorCode defaultErrorCodeToReport,
uint32_t collectedErrors,
PRErrorCode errorCodeTrust,
PRErrorCode errorCodeMismatch,
PRErrorCode errorCodeTime,
uint32_t providerFlags)
: mFdForLogging(fdForLogging), mCert(cert), mInfoObject(infoObject),
mDefaultErrorCodeToReport(defaultErrorCodeToReport),
mCollectedErrors(collectedErrors),
mErrorCodeTrust(errorCodeTrust),
mErrorCodeMismatch(errorCodeMismatch),
mErrorCodeTime(errorCodeTime),
mProviderFlags(providerFlags)
{
}
virtual void RunOnTargetThread();
RefPtr<SSLServerCertVerificationResult> mResult; // out
private:
SSLServerCertVerificationResult* CheckCertOverrides();
const void* const mFdForLogging; // may become an invalid pointer; do not dereference
const nsCOMPtr<nsIX509Cert> mCert;
const RefPtr<nsNSSSocketInfo> mInfoObject;
const PRErrorCode mDefaultErrorCodeToReport;
const uint32_t mCollectedErrors;
const PRErrorCode mErrorCodeTrust;
const PRErrorCode mErrorCodeMismatch;
const PRErrorCode mErrorCodeTime;
const uint32_t mProviderFlags;
};
SECStatus
DetermineCertOverrideErrors(const UniqueCERTCertificate& cert,
const char* hostName,
PRTime now, PRErrorCode defaultErrorCodeToReport,
/*out*/ uint32_t& collectedErrors,
/*out*/ PRErrorCode& errorCodeTrust,
/*out*/ PRErrorCode& errorCodeMismatch,
/*out*/ PRErrorCode& errorCodeTime)
{
MOZ_ASSERT(cert);
MOZ_ASSERT(hostName);
MOZ_ASSERT(collectedErrors == 0);
MOZ_ASSERT(errorCodeTrust == 0);
MOZ_ASSERT(errorCodeMismatch == 0);
MOZ_ASSERT(errorCodeTime == 0);
// Assumes the error prioritization described in mozilla::pkix's
// BuildForward function. Also assumes that CheckCertHostname was only
// called if CertVerifier::VerifyCert succeeded.
switch (defaultErrorCodeToReport) {
case SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED:
case SEC_ERROR_EXPIRED_ISSUER_CERTIFICATE:
case SEC_ERROR_UNKNOWN_ISSUER:
case SEC_ERROR_CA_CERT_INVALID:
case mozilla::pkix::MOZILLA_PKIX_ERROR_CA_CERT_USED_AS_END_ENTITY:
case mozilla::pkix::MOZILLA_PKIX_ERROR_INADEQUATE_KEY_SIZE:
case mozilla::pkix::MOZILLA_PKIX_ERROR_V1_CERT_USED_AS_CA:
case mozilla::pkix::MOZILLA_PKIX_ERROR_NOT_YET_VALID_ISSUER_CERTIFICATE:
case mozilla::pkix::MOZILLA_PKIX_ERROR_EMPTY_ISSUER_NAME:
{
collectedErrors = nsICertOverrideService::ERROR_UNTRUSTED;
errorCodeTrust = defaultErrorCodeToReport;
SECCertTimeValidity validity = CERT_CheckCertValidTimes(cert.get(), now,
false);
if (validity == secCertTimeUndetermined) {
// This only happens if cert is null. CERT_CheckCertValidTimes will
// have set the error code to SEC_ERROR_INVALID_ARGS. We should really
// be using mozilla::pkix here anyway.
MOZ_ASSERT(PR_GetError() == SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (validity == secCertTimeExpired) {
collectedErrors |= nsICertOverrideService::ERROR_TIME;
errorCodeTime = SEC_ERROR_EXPIRED_CERTIFICATE;
} else if (validity == secCertTimeNotValidYet) {
collectedErrors |= nsICertOverrideService::ERROR_TIME;
errorCodeTime =
mozilla::pkix::MOZILLA_PKIX_ERROR_NOT_YET_VALID_CERTIFICATE;
}
break;
}
case SEC_ERROR_INVALID_TIME:
case SEC_ERROR_EXPIRED_CERTIFICATE:
case mozilla::pkix::MOZILLA_PKIX_ERROR_NOT_YET_VALID_CERTIFICATE:
collectedErrors = nsICertOverrideService::ERROR_TIME;
errorCodeTime = defaultErrorCodeToReport;
break;
case SSL_ERROR_BAD_CERT_DOMAIN:
collectedErrors = nsICertOverrideService::ERROR_MISMATCH;
errorCodeMismatch = SSL_ERROR_BAD_CERT_DOMAIN;
break;
case 0:
NS_ERROR("No error code set during certificate validation failure.");
PR_SetError(PR_INVALID_STATE_ERROR, 0);
return SECFailure;
default:
PR_SetError(defaultErrorCodeToReport, 0);
return SECFailure;
}
if (defaultErrorCodeToReport != SSL_ERROR_BAD_CERT_DOMAIN) {
Input certInput;
if (certInput.Init(cert->derCert.data, cert->derCert.len) != Success) {
PR_SetError(SEC_ERROR_BAD_DER, 0);
return SECFailure;
}
Input hostnameInput;
Result result = hostnameInput.Init(
BitwiseCast<const uint8_t*, const char*>(hostName),
strlen(hostName));
if (result != Success) {
PR_SetError(SEC_ERROR_INVALID_ARGS, 0);
return SECFailure;
}
// Use a lax policy so as to not generate potentially spurious name
// mismatch "hints".
BRNameMatchingPolicy nameMatchingPolicy(
BRNameMatchingPolicy::Mode::DoNotEnforce);
// CheckCertHostname expects that its input represents a certificate that
// has already been successfully validated by BuildCertChain. This is
// obviously not the case, however, because we're in the error path of
// certificate verification. Thus, this is problematic. In the future, it
// would be nice to remove this optimistic additional error checking and
// simply punt to the front-end, which can more easily (and safely) perform
// extra checks to give the user hints as to why verification failed.
result = CheckCertHostname(certInput, hostnameInput, nameMatchingPolicy);
// Treat malformed name information as a domain mismatch.
if (result == Result::ERROR_BAD_DER ||
result == Result::ERROR_BAD_CERT_DOMAIN) {
collectedErrors |= nsICertOverrideService::ERROR_MISMATCH;
errorCodeMismatch = SSL_ERROR_BAD_CERT_DOMAIN;
} else if (IsFatalError(result)) {
// Because its input has not been validated by BuildCertChain,
// CheckCertHostname can return an error that is less important than the
// original certificate verification error. Only return an error result
// from this function if we've encountered a fatal error.
PR_SetError(MapResultToPRErrorCode(result), 0);
return SECFailure;
}
}
return SECSuccess;
}
SSLServerCertVerificationResult*
CertErrorRunnable::CheckCertOverrides()
{
MOZ_LOG(gPIPNSSLog, LogLevel::Debug, ("[%p][%p] top of CheckCertOverrides\n",
mFdForLogging, this));
// "Use" mFdForLogging in non-PR_LOGGING builds, too, to suppress
// clang's -Wunused-private-field build warning for this variable:
Unused << mFdForLogging;
if (!NS_IsMainThread()) {
NS_ERROR("CertErrorRunnable::CheckCertOverrides called off main thread");
return new SSLServerCertVerificationResult(mInfoObject,
mDefaultErrorCodeToReport);
}
int32_t port;
mInfoObject->GetPort(&port);
nsAutoCString hostWithPortString(mInfoObject->GetHostName());
hostWithPortString.Append(':');
hostWithPortString.AppendInt(port);
uint32_t remaining_display_errors = mCollectedErrors;
// If this is an HTTP Strict Transport Security host, don't allow overrides
// RFC 6797 section 12.1.
bool strictTransportSecurityEnabled = false;
nsCOMPtr<nsISiteSecurityService> sss(do_GetService(NS_SSSERVICE_CONTRACTID));
if (!sss) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] couldn't get nsISiteSecurityService to check for HSTS/HPKP\n",
mFdForLogging, this));
return new SSLServerCertVerificationResult(mInfoObject,
mDefaultErrorCodeToReport);
}
nsresult nsrv = sss->IsSecureHost(nsISiteSecurityService::HEADER_HSTS,
mInfoObject->GetHostNameRaw(),
mProviderFlags,
nullptr,
&strictTransportSecurityEnabled);
if (NS_FAILED(nsrv)) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] checking for HSTS failed\n", mFdForLogging, this));
return new SSLServerCertVerificationResult(mInfoObject,
mDefaultErrorCodeToReport);
}
if (!strictTransportSecurityEnabled) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] no HSTS - overrides allowed\n",
mFdForLogging, this));
nsCOMPtr<nsICertOverrideService> overrideService =
do_GetService(NS_CERTOVERRIDE_CONTRACTID);
// it is fine to continue without the nsICertOverrideService
uint32_t overrideBits = 0;
if (overrideService)
{
bool haveOverride;
bool isTemporaryOverride; // we don't care
const nsACString& hostString(mInfoObject->GetHostName());
nsrv = overrideService->HasMatchingOverride(hostString, port,
mCert,
&overrideBits,
&isTemporaryOverride,
&haveOverride);
if (NS_SUCCEEDED(nsrv) && haveOverride)
{
// remove the errors that are already overriden
remaining_display_errors &= ~overrideBits;
}
}
if (!remaining_display_errors) {
// all errors are covered by override rules, so let's accept the cert
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] All errors covered by override rules\n",
mFdForLogging, this));
return new SSLServerCertVerificationResult(mInfoObject, 0);
}
} else {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] HSTS - no overrides allowed\n",
mFdForLogging, this));
}
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] Certificate error was not overridden\n",
mFdForLogging, this));
// Ok, this is a full stop.
// First, deliver the technical details of the broken SSL status.
// Try to get a nsIBadCertListener2 implementation from the socket consumer.
nsCOMPtr<nsISSLSocketControl> sslSocketControl = do_QueryInterface(
NS_ISUPPORTS_CAST(nsITransportSecurityInfo*, mInfoObject));
if (sslSocketControl) {
nsCOMPtr<nsIInterfaceRequestor> cb;
sslSocketControl->GetNotificationCallbacks(getter_AddRefs(cb));
if (cb) {
nsCOMPtr<nsIBadCertListener2> bcl = do_GetInterface(cb);
if (bcl) {
nsIInterfaceRequestor* csi
= static_cast<nsIInterfaceRequestor*>(mInfoObject);
bool suppressMessage = false; // obsolete, ignored
nsrv = bcl->NotifyCertProblem(csi, mInfoObject->SSLStatus(),
hostWithPortString, &suppressMessage);
}
}
}
// pick the error code to report by priority
PRErrorCode errorCodeToReport = mErrorCodeTrust ? mErrorCodeTrust
: mErrorCodeMismatch ? mErrorCodeMismatch
: mErrorCodeTime ? mErrorCodeTime
: mDefaultErrorCodeToReport;
SSLServerCertVerificationResult* result =
new SSLServerCertVerificationResult(mInfoObject,
errorCodeToReport,
OverridableCertErrorMessage);
LogInvalidCertError(mInfoObject,
result->mErrorCode,
result->mErrorMessageType);
return result;
}
void
CertErrorRunnable::RunOnTargetThread()
{
MOZ_ASSERT(NS_IsMainThread());
mResult = CheckCertOverrides();
MOZ_ASSERT(mResult);
}
// Returns null with the error code (PR_GetError()) set if it does not create
// the CertErrorRunnable.
CertErrorRunnable*
CreateCertErrorRunnable(CertVerifier& certVerifier,
PRErrorCode defaultErrorCodeToReport,
nsNSSSocketInfo* infoObject,
const UniqueCERTCertificate& cert,
const void* fdForLogging,
uint32_t providerFlags,
PRTime now)
{
MOZ_ASSERT(infoObject);
MOZ_ASSERT(cert);
uint32_t collected_errors = 0;
PRErrorCode errorCodeTrust = 0;
PRErrorCode errorCodeMismatch = 0;
PRErrorCode errorCodeTime = 0;
if (DetermineCertOverrideErrors(cert, infoObject->GetHostNameRaw(), now,
defaultErrorCodeToReport, collected_errors,
errorCodeTrust, errorCodeMismatch,
errorCodeTime) != SECSuccess) {
// Attempt to enforce that if DetermineCertOverrideErrors failed,
// PR_SetError was set with a non-overridable error. This is because if we
// return from CreateCertErrorRunnable without calling
// infoObject->SetStatusErrorBits, we won't have the required information
// to actually add a certificate error override. This results in a broken
// UI which is annoying but not a security disaster.
MOZ_ASSERT(!ErrorIsOverridable(PR_GetError()));
return nullptr;
}
RefPtr<nsNSSCertificate> nssCert(nsNSSCertificate::Create(cert.get()));
if (!nssCert) {
NS_ERROR("nsNSSCertificate::Create failed");
PR_SetError(SEC_ERROR_NO_MEMORY, 0);
return nullptr;
}
if (!collected_errors) {
// This will happen when CERT_*Verify* only returned error(s) that are
// not on our whitelist of overridable certificate errors.
MOZ_LOG(gPIPNSSLog, LogLevel::Debug, ("[%p] !collected_errors: %d\n",
fdForLogging, static_cast<int>(defaultErrorCodeToReport)));
PR_SetError(defaultErrorCodeToReport, 0);
return nullptr;
}
infoObject->SetStatusErrorBits(nssCert, collected_errors);
return new CertErrorRunnable(fdForLogging,
static_cast<nsIX509Cert*>(nssCert.get()),
infoObject, defaultErrorCodeToReport,
collected_errors, errorCodeTrust,
errorCodeMismatch, errorCodeTime,
providerFlags);
}
// When doing async cert processing, we dispatch one of these runnables to the
// socket transport service thread, which blocks the socket transport
// service thread while it waits for the inner CertErrorRunnable to execute
// CheckCertOverrides on the main thread. CheckCertOverrides must block events
// on both of these threads because it calls TransportSecurityInfo::GetInterface(),
// which may call nsHttpConnection::GetInterface() through
// TransportSecurityInfo::mCallbacks. nsHttpConnection::GetInterface must always
// execute on the main thread, with the socket transport service thread
// blocked.
class CertErrorRunnableRunnable : public Runnable
{
public:
explicit CertErrorRunnableRunnable(CertErrorRunnable* certErrorRunnable)
: mCertErrorRunnable(certErrorRunnable)
{
}
private:
NS_IMETHOD Run() override
{
nsresult rv = mCertErrorRunnable->DispatchToMainThreadAndWait();
// The result must run on the socket transport thread, which we are already
// on, so we can just run it directly, instead of dispatching it.
if (NS_SUCCEEDED(rv)) {
rv = mCertErrorRunnable->mResult ? mCertErrorRunnable->mResult->Run()
: NS_ERROR_UNEXPECTED;
}
return rv;
}
RefPtr<CertErrorRunnable> mCertErrorRunnable;
};
class SSLServerCertVerificationJob : public Runnable
{
public:
// Must be called only on the socket transport thread
static SECStatus Dispatch(const RefPtr<SharedCertVerifier>& certVerifier,
const void* fdForLogging,
nsNSSSocketInfo* infoObject,
const UniqueCERTCertificate& serverCert,
const UniqueCERTCertList& peerCertChain,
const SECItem* stapledOCSPResponse,
const SECItem* sctsFromTLSExtension,
uint32_t providerFlags,
Time time,
PRTime prtime);
private:
NS_DECL_NSIRUNNABLE
// Must be called only on the socket transport thread
SSLServerCertVerificationJob(const RefPtr<SharedCertVerifier>& certVerifier,
const void* fdForLogging,
nsNSSSocketInfo* infoObject,
const UniqueCERTCertificate& cert,
UniqueCERTCertList peerCertChain,
const SECItem* stapledOCSPResponse,
const SECItem* sctsFromTLSExtension,
uint32_t providerFlags,
Time time,
PRTime prtime);
const RefPtr<SharedCertVerifier> mCertVerifier;
const void* const mFdForLogging;
const RefPtr<nsNSSSocketInfo> mInfoObject;
const UniqueCERTCertificate mCert;
UniqueCERTCertList mPeerCertChain;
const uint32_t mProviderFlags;
const Time mTime;
const PRTime mPRTime;
const TimeStamp mJobStartTime;
const UniqueSECItem mStapledOCSPResponse;
const UniqueSECItem mSCTsFromTLSExtension;
};
SSLServerCertVerificationJob::SSLServerCertVerificationJob(
const RefPtr<SharedCertVerifier>& certVerifier, const void* fdForLogging,
nsNSSSocketInfo* infoObject, const UniqueCERTCertificate& cert,
UniqueCERTCertList peerCertChain, const SECItem* stapledOCSPResponse,
const SECItem* sctsFromTLSExtension,
uint32_t providerFlags, Time time, PRTime prtime)
: mCertVerifier(certVerifier)
, mFdForLogging(fdForLogging)
, mInfoObject(infoObject)
, mCert(CERT_DupCertificate(cert.get()))
, mPeerCertChain(Move(peerCertChain))
, mProviderFlags(providerFlags)
, mTime(time)
, mPRTime(prtime)
, mJobStartTime(TimeStamp::Now())
, mStapledOCSPResponse(SECITEM_DupItem(stapledOCSPResponse))
, mSCTsFromTLSExtension(SECITEM_DupItem(sctsFromTLSExtension))
{
}
// This function assumes that we will only use the SPDY connection coalescing
// feature on connections where we have negotiated SPDY using NPN. If we ever
// talk SPDY without having negotiated it with SPDY, this code will give wrong
// and perhaps unsafe results.
//
// Returns SECSuccess on the initial handshake of all connections, on
// renegotiations for any connections where we did not negotiate SPDY, or on any
// SPDY connection where the server's certificate did not change.
//
// Prohibit changing the server cert only if we negotiated SPDY,
// in order to support SPDY's cross-origin connection pooling.
static SECStatus
BlockServerCertChangeForSpdy(nsNSSSocketInfo* infoObject,
const UniqueCERTCertificate& serverCert)
{
// Get the existing cert. If there isn't one, then there is
// no cert change to worry about.
nsCOMPtr<nsIX509Cert> cert;
RefPtr<nsSSLStatus> status(infoObject->SSLStatus());
if (!status) {
// If we didn't have a status, then this is the
// first handshake on this connection, not a
// renegotiation.
return SECSuccess;
}
status->GetServerCert(getter_AddRefs(cert));
if (!cert) {
NS_NOTREACHED("every nsSSLStatus must have a cert"
"that implements nsIX509Cert");
PR_SetError(SEC_ERROR_LIBRARY_FAILURE, 0);
return SECFailure;
}
// Filter out sockets that did not neogtiate SPDY via NPN
nsAutoCString negotiatedNPN;
nsresult rv = infoObject->GetNegotiatedNPN(negotiatedNPN);
NS_ASSERTION(NS_SUCCEEDED(rv),
"GetNegotiatedNPN() failed during renegotiation");
if (NS_SUCCEEDED(rv) && !StringBeginsWith(negotiatedNPN,
NS_LITERAL_CSTRING("spdy/"))) {
return SECSuccess;
}
// If GetNegotiatedNPN() failed we will assume spdy for safety's safe
if (NS_FAILED(rv)) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("BlockServerCertChangeForSpdy failed GetNegotiatedNPN() call."
" Assuming spdy.\n"));
}
// Check to see if the cert has actually changed
UniqueCERTCertificate c(cert->GetCert());
NS_ASSERTION(c, "very bad and hopefully impossible state");
bool sameCert = CERT_CompareCerts(c.get(), serverCert.get());
if (sameCert) {
return SECSuccess;
}
// Report an error - changed cert is confirmed
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("SPDY Refused to allow new cert during renegotiation\n"));
PR_SetError(SSL_ERROR_RENEGOTIATION_NOT_ALLOWED, 0);
return SECFailure;
}
// Note: Takes ownership of |peerCertChain| if SECSuccess is not returned.
SECStatus
AuthCertificate(CertVerifier& certVerifier,
nsNSSSocketInfo* infoObject,
const UniqueCERTCertificate& cert,
UniqueCERTCertList& peerCertChain,
const SECItem* stapledOCSPResponse,
const SECItem* sctsFromTLSExtension,
uint32_t providerFlags,
Time time)
{
MOZ_ASSERT(infoObject);
MOZ_ASSERT(cert);
// We want to avoid storing any intermediate cert information when browsing
// in private, transient contexts.
bool saveIntermediates =
!(providerFlags & nsISocketProvider::NO_PERMANENT_STORAGE);
SECOidTag evOidPolicy;
UniqueCERTCertList certList;
CertVerifier::OCSPStaplingStatus ocspStaplingStatus =
CertVerifier::OCSP_STAPLING_NEVER_CHECKED;
KeySizeStatus keySizeStatus = KeySizeStatus::NeverChecked;
SHA1ModeResult sha1ModeResult = SHA1ModeResult::NeverChecked;
CertificateTransparencyInfo certificateTransparencyInfo;
int flags = 0;
if (!infoObject->SharedState().IsOCSPStaplingEnabled() ||
!infoObject->SharedState().IsOCSPMustStapleEnabled()) {
flags |= CertVerifier::FLAG_TLS_IGNORE_STATUS_REQUEST;
}
Result rv = certVerifier.VerifySSLServerCert(cert, stapledOCSPResponse,
sctsFromTLSExtension, time,
infoObject,
infoObject->GetHostNameRaw(),
certList, saveIntermediates,
flags, infoObject->
GetOriginAttributes(),
&evOidPolicy,
&ocspStaplingStatus,
&keySizeStatus, &sha1ModeResult,
&certificateTransparencyInfo);
if (rv == Success) {
// Certificate verification succeeded. Delete any potential record of
// certificate error bits.
RememberCertErrorsTable::GetInstance().RememberCertHasError(infoObject,
nullptr,
SECSuccess);
// The connection may get terminated, for example, if the server requires
// a client cert. Let's provide a minimal SSLStatus
// to the caller that contains at least the cert and its status.
RefPtr<nsSSLStatus> status(infoObject->SSLStatus());
if (!status) {
status = new nsSSLStatus();
infoObject->SetSSLStatus(status);
}
if (!status->HasServerCert()) {
EVStatus evStatus;
if (evOidPolicy == SEC_OID_UNKNOWN) {
evStatus = EVStatus::NotEV;
} else {
evStatus = EVStatus::EV;
}
RefPtr<nsNSSCertificate> nsc = nsNSSCertificate::Create(cert.get());
status->SetServerCert(nsc, evStatus);
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("AuthCertificate setting NEW cert %p", nsc.get()));
}
status->SetCertificateTransparencyInfo(certificateTransparencyInfo);
}
if (rv != Success) {
// Certificate validation failed; store the peer certificate chain on
// infoObject so it can be used for error reporting.
infoObject->SetFailedCertChain(Move(peerCertChain));
PR_SetError(MapResultToPRErrorCode(rv), 0);
}
return rv == Success ? SECSuccess : SECFailure;
}
/*static*/ SECStatus
SSLServerCertVerificationJob::Dispatch(
const RefPtr<SharedCertVerifier>& certVerifier,
const void* fdForLogging,
nsNSSSocketInfo* infoObject,
const UniqueCERTCertificate& serverCert,
const UniqueCERTCertList& peerCertChain,
const SECItem* stapledOCSPResponse,
const SECItem* sctsFromTLSExtension,
uint32_t providerFlags,
Time time,
PRTime prtime)
{
// Runs on the socket transport thread
if (!certVerifier || !infoObject || !serverCert) {
NS_ERROR("Invalid parameters for SSL server cert validation");
PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
return SECFailure;
}
// Copy the certificate list so the runnable can take ownership of it in the
// constructor.
// We can safely skip checking if NSS has already shut down here since we're
// in the middle of verifying a certificate.
nsNSSShutDownPreventionLock lock;
UniqueCERTCertList peerCertChainCopy =
nsNSSCertList::DupCertList(peerCertChain, lock);
if (!peerCertChainCopy) {
PR_SetError(SEC_ERROR_NO_MEMORY, 0);
return SECFailure;
}
RefPtr<SSLServerCertVerificationJob> job(
new SSLServerCertVerificationJob(certVerifier, fdForLogging, infoObject,
serverCert, Move(peerCertChainCopy),
stapledOCSPResponse, sctsFromTLSExtension,
providerFlags, time, prtime));
nsresult nrv;
if (!gCertVerificationThreadPool) {
nrv = NS_ERROR_NOT_INITIALIZED;
} else {
nrv = gCertVerificationThreadPool->Dispatch(job, NS_DISPATCH_NORMAL);
}
if (NS_FAILED(nrv)) {
// We can't call SetCertVerificationResult here to change
// mCertVerificationState because SetCertVerificationResult will call
// libssl functions that acquire SSL locks that are already being held at
// this point. infoObject->mCertVerificationState will be stuck at
// waiting_for_cert_verification here, but that is OK because we already
// have to be able to handle cases where we encounter non-cert errors while
// in that state.
PRErrorCode error = nrv == NS_ERROR_OUT_OF_MEMORY
? SEC_ERROR_NO_MEMORY
: PR_INVALID_STATE_ERROR;
PORT_SetError(error);
return SECFailure;
}
PORT_SetError(PR_WOULD_BLOCK_ERROR);
return SECWouldBlock;
}
NS_IMETHODIMP
SSLServerCertVerificationJob::Run()
{
// Runs on a cert verification thread
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] SSLServerCertVerificationJob::Run\n", mInfoObject.get()));
PRErrorCode error;
nsNSSShutDownPreventionLock nssShutdownPrevention;
if (mInfoObject->isAlreadyShutDown()) {
error = SEC_ERROR_USER_CANCELLED;
} else {
// Reset the error code here so we can detect if AuthCertificate fails to
// set the error code if/when it fails.
PR_SetError(0, 0);
SECStatus rv = AuthCertificate(*mCertVerifier, mInfoObject, mCert,
mPeerCertChain, mStapledOCSPResponse.get(),
mSCTsFromTLSExtension.get(),
mProviderFlags, mTime);
MOZ_ASSERT(mPeerCertChain || rv != SECSuccess,
"AuthCertificate() should take ownership of chain on failure");
if (rv == SECSuccess) {
RefPtr<SSLServerCertVerificationResult> restart(
new SSLServerCertVerificationResult(mInfoObject, 0));
restart->Dispatch();
return NS_OK;
}
// Note: the interval is not calculated once as PR_GetError MUST be called
// before any other function call
error = PR_GetError();
if (error != 0) {
RefPtr<CertErrorRunnable> runnable(
CreateCertErrorRunnable(*mCertVerifier, error, mInfoObject, mCert,
mFdForLogging, mProviderFlags, mPRTime));
if (!runnable) {
// CreateCertErrorRunnable set a new error code
error = PR_GetError();
} else {
// We must block the the socket transport service thread while the
// main thread executes the CertErrorRunnable. The CertErrorRunnable
// will dispatch the result asynchronously, so we don't have to block
// this thread waiting for it.
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p][%p] Before dispatching CertErrorRunnable\n",
mFdForLogging, runnable.get()));
nsresult nrv;
nsCOMPtr<nsIEventTarget> stsTarget
= do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &nrv);
if (NS_SUCCEEDED(nrv)) {
nrv = stsTarget->Dispatch(new CertErrorRunnableRunnable(runnable),
NS_DISPATCH_NORMAL);
}
if (NS_SUCCEEDED(nrv)) {
return NS_OK;
}
NS_ERROR("Failed to dispatch CertErrorRunnable");
error = PR_INVALID_STATE_ERROR;
}
}
}
if (error == 0) {
NS_NOTREACHED("no error set during certificate validation failure");
error = PR_INVALID_STATE_ERROR;
}
RefPtr<SSLServerCertVerificationResult> failure(
new SSLServerCertVerificationResult(mInfoObject, error));
failure->Dispatch();
return NS_OK;
}
} // unnamed namespace
// Extracts whatever information we need out of fd (using SSL_*) and passes it
// to SSLServerCertVerificationJob::Dispatch. SSLServerCertVerificationJob should
// never do anything with fd except logging.
SECStatus
AuthCertificateHook(void* arg, PRFileDesc* fd, PRBool checkSig, PRBool isServer)
{
RefPtr<SharedCertVerifier> certVerifier(GetDefaultCertVerifier());
if (!certVerifier) {
PR_SetError(SEC_ERROR_NOT_INITIALIZED, 0);
return SECFailure;
}
// Runs on the socket transport thread
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] starting AuthCertificateHook\n", fd));
// Modern libssl always passes PR_TRUE for checkSig, and we have no means of
// doing verification without checking signatures.
NS_ASSERTION(checkSig, "AuthCertificateHook: checkSig unexpectedly false");
// PSM never causes libssl to call this function with PR_TRUE for isServer,
// and many things in PSM assume that we are a client.
NS_ASSERTION(!isServer, "AuthCertificateHook: isServer unexpectedly true");
nsNSSSocketInfo* socketInfo = static_cast<nsNSSSocketInfo*>(arg);
UniqueCERTCertificate serverCert(SSL_PeerCertificate(fd));
if (!checkSig || isServer || !socketInfo || !serverCert) {
PR_SetError(PR_INVALID_STATE_ERROR, 0);
return SECFailure;
}
// Get the peer certificate chain for error reporting
UniqueCERTCertList peerCertChain(SSL_PeerCertificateChain(fd));
if (!peerCertChain) {
PR_SetError(PR_INVALID_STATE_ERROR, 0);
return SECFailure;
}
socketInfo->SetFullHandshake();
Time now(Now());
PRTime prnow(PR_Now());
if (BlockServerCertChangeForSpdy(socketInfo, serverCert) != SECSuccess)
return SECFailure;
nsCOMPtr<nsISSLSocketControl> sslSocketControl = do_QueryInterface(
NS_ISUPPORTS_CAST(nsITransportSecurityInfo*, socketInfo));
if (sslSocketControl && sslSocketControl->GetBypassAuthentication()) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] Bypass Auth in AuthCertificateHook\n", fd));
return SECSuccess;
}
bool onSTSThread;
nsresult nrv;
nsCOMPtr<nsIEventTarget> sts
= do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &nrv);
if (NS_SUCCEEDED(nrv)) {
nrv = sts->IsOnCurrentThread(&onSTSThread);
}
if (NS_FAILED(nrv)) {
NS_ERROR("Could not get STS service or IsOnCurrentThread failed");
PR_SetError(PR_UNKNOWN_ERROR, 0);
return SECFailure;
}
// SSL_PeerStapledOCSPResponses will never return a non-empty response if
// OCSP stapling wasn't enabled because libssl wouldn't have let the server
// return a stapled OCSP response.
// We don't own these pointers.
const SECItemArray* csa = SSL_PeerStapledOCSPResponses(fd);
SECItem* stapledOCSPResponse = nullptr;
// we currently only support single stapled responses
if (csa && csa->len == 1) {
stapledOCSPResponse = &csa->items[0];
}
const SECItem* sctsFromTLSExtension = SSL_PeerSignedCertTimestamps(fd);
if (sctsFromTLSExtension && sctsFromTLSExtension->len == 0) {
// SSL_PeerSignedCertTimestamps returns null on error and empty item
// when no extension was returned by the server. We always use null when
// no extension was received (for whatever reason), ignoring errors.
sctsFromTLSExtension = nullptr;
}
uint32_t providerFlags = 0;
socketInfo->GetProviderFlags(&providerFlags);
if (onSTSThread) {
// We *must* do certificate verification on a background thread because
// we need the socket transport thread to be free for our OCSP requests,
// and we *want* to do certificate verification on a background thread
// because of the performance benefits of doing so.
socketInfo->SetCertVerificationWaiting();
SECStatus rv = SSLServerCertVerificationJob::Dispatch(
certVerifier, static_cast<const void*>(fd), socketInfo,
serverCert, peerCertChain, stapledOCSPResponse,
sctsFromTLSExtension, providerFlags, now, prnow);
return rv;
}
// We can't do certificate verification on a background thread, because the
// thread doing the network I/O may not interrupt its network I/O on receipt
// of our SSLServerCertVerificationResult event, and/or it might not even be
// a non-blocking socket.
SECStatus rv = AuthCertificate(*certVerifier, socketInfo, serverCert,
peerCertChain, stapledOCSPResponse,
sctsFromTLSExtension, providerFlags, now);
MOZ_ASSERT(peerCertChain || rv != SECSuccess,
"AuthCertificate() should take ownership of chain on failure");
if (rv == SECSuccess) {
return SECSuccess;
}
PRErrorCode error = PR_GetError();
if (error != 0) {
RefPtr<CertErrorRunnable> runnable(
CreateCertErrorRunnable(*certVerifier, error, socketInfo, serverCert,
static_cast<const void*>(fd), providerFlags,
prnow));
if (!runnable) {
// CreateCertErrorRunnable sets a new error code when it fails
error = PR_GetError();
} else {
// We have to return SECSuccess or SECFailure based on the result of the
// override processing, so we must block this thread waiting for it. The
// CertErrorRunnable will NOT dispatch the result at all, since we passed
// false for CreateCertErrorRunnable's async parameter
nrv = runnable->DispatchToMainThreadAndWait();
if (NS_FAILED(nrv)) {
NS_ERROR("Failed to dispatch CertErrorRunnable");
PR_SetError(PR_INVALID_STATE_ERROR, 0);
return SECFailure;
}
if (!runnable->mResult) {
NS_ERROR("CertErrorRunnable did not set result");
PR_SetError(PR_INVALID_STATE_ERROR, 0);
return SECFailure;
}
if (runnable->mResult->mErrorCode == 0) {
return SECSuccess; // cert error override occurred.
}
// We must call SetCanceled here to set the error message type
// in case it isn't PlainErrorMessage, which is what we would
// default to if we just called
// PR_SetError(runnable->mResult->mErrorCode, 0) and returned
// SECFailure without doing this.
socketInfo->SetCanceled(runnable->mResult->mErrorCode,
runnable->mResult->mErrorMessageType);
error = runnable->mResult->mErrorCode;
}
}
if (error == 0) {
NS_ERROR("error code not set");
error = PR_UNKNOWN_ERROR;
}
PR_SetError(error, 0);
return SECFailure;
}
SSLServerCertVerificationResult::SSLServerCertVerificationResult(
nsNSSSocketInfo* infoObject, PRErrorCode errorCode,
SSLErrorMessageType errorMessageType)
: mInfoObject(infoObject)
, mErrorCode(errorCode)
, mErrorMessageType(errorMessageType)
{
}
void
SSLServerCertVerificationResult::Dispatch()
{
nsresult rv;
nsCOMPtr<nsIEventTarget> stsTarget
= do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &rv);
NS_ASSERTION(stsTarget,
"Failed to get socket transport service event target");
rv = stsTarget->Dispatch(this, NS_DISPATCH_NORMAL);
NS_ASSERTION(NS_SUCCEEDED(rv),
"Failed to dispatch SSLServerCertVerificationResult");
}
NS_IMETHODIMP
SSLServerCertVerificationResult::Run()
{
// XXX: This cast will be removed by the next patch
((nsNSSSocketInfo*) mInfoObject.get())
->SetCertVerificationResult(mErrorCode, mErrorMessageType);
return NS_OK;
}
} } // namespace mozilla::psm