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/* -*- 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/. */
#include "nsNSSIOLayer.h"
#include <algorithm>
#include <utility>
#include <vector>
#include "NSSCertDBTrustDomain.h"
#include "NSSErrorsService.h"
#include "NSSSocketControl.h"
#include "PSMRunnable.h"
#include "SSLServerCertVerification.h"
#include "ScopedNSSTypes.h"
#include "SharedSSLState.h"
#include "TLSClientAuthCertSelection.h"
#include "keyhi.h"
#include "mozilla/Base64.h"
#include "mozilla/Casting.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Logging.h"
#include "mozilla/Preferences.h"
#include "mozilla/RandomNum.h"
#include "mozilla/StaticPrefs_security.h"
#include "mozilla/Telemetry.h"
#include "mozilla/ipc/BackgroundChild.h"
#include "mozilla/ipc/PBackgroundChild.h"
#include "mozilla/net/SSLTokensCache.h"
#include "mozilla/net/SocketProcessChild.h"
#include "mozilla/psm/IPCClientCertsChild.h"
#include "mozilla/psm/PIPCClientCertsChild.h"
#include "mozpkix/pkixnss.h"
#include "mozpkix/pkixtypes.h"
#include "mozpkix/pkixutil.h"
#include "nsArray.h"
#include "nsArrayUtils.h"
#include "nsCRT.h"
#include "nsCharSeparatedTokenizer.h"
#include "nsClientAuthRemember.h"
#include "nsContentUtils.h"
#include "nsIClientAuthDialogs.h"
#include "nsISocketProvider.h"
#include "nsISocketTransport.h"
#include "nsIWebProgressListener.h"
#include "nsNSSCertHelper.h"
#include "nsNSSComponent.h"
#include "nsNSSHelper.h"
#include "nsPrintfCString.h"
#include "nsServiceManagerUtils.h"
#include "prmem.h"
#include "prnetdb.h"
#include "secder.h"
#include "secerr.h"
#include "ssl.h"
#include "sslerr.h"
#include "sslexp.h"
#include "sslproto.h"
using namespace mozilla::psm;
using namespace mozilla::ipc;
// #define DEBUG_SSL_VERBOSE //Enable this define to get minimal
// reports when doing SSL read/write
// #define DUMP_BUFFER //Enable this define along with
// DEBUG_SSL_VERBOSE to dump SSL
// read/write buffer to a log.
// Uses PR_LOG except on Mac where
// we always write out to our own
// file.
namespace {
// The NSSSocketInfo tls flags are meant to be opaque to most calling
// applications but provide a mechanism for direct TLS manipulation when
// experimenting with new features in the scope of a single socket. They do not
// create a persistent ABI.
//
// Use of these flags creates a new 'sharedSSLState' so existing states for
// intolerance are not carried to sockets that use these flags (and intolerance
// they discover does not impact other normal sockets not using the flags.)
//
// Their current definitions are:
//
// bits 0-2 (mask 0x07) specify the max tls version
// 0 means no override 1->4 are 1.0, 1.1, 1.2, 1.3, 4->7 unused
// bits 3-5 (mask 0x38) specify the tls fallback limit
// 0 means no override, values 1->4 match prefs
// bit 6 (mask 0x40) was used to specify compat mode. Temporarily reserved.
enum {
kTLSProviderFlagMaxVersion10 = 0x01,
kTLSProviderFlagMaxVersion11 = 0x02,
kTLSProviderFlagMaxVersion12 = 0x03,
kTLSProviderFlagMaxVersion13 = 0x04,
};
static uint32_t getTLSProviderFlagMaxVersion(uint32_t flags) {
return (flags & 0x07);
}
static uint32_t getTLSProviderFlagFallbackLimit(uint32_t flags) {
return (flags & 0x38) >> 3;
}
void getSiteKey(const nsACString& hostName, uint16_t port,
/*out*/ nsACString& key) {
key = hostName;
key.AppendLiteral(":");
key.AppendInt(port);
}
} // unnamed namespace
extern LazyLogModule gPIPNSSLog;
void nsSSLIOLayerHelpers::Cleanup() {
MutexAutoLock lock(mutex);
mTLSIntoleranceInfo.Clear();
mInsecureFallbackSites.Clear();
}
namespace {
enum Operation { reading, writing, not_reading_or_writing };
int32_t checkHandshake(int32_t bytesTransfered, bool wasReading,
PRFileDesc* ssl_layer_fd, NSSSocketControl* socketInfo);
NSSSocketControl* getSocketInfoIfRunning(PRFileDesc* fd, Operation op) {
if (!fd || !fd->lower || !fd->secret ||
fd->identity != nsSSLIOLayerHelpers::nsSSLIOLayerIdentity) {
NS_ERROR("bad file descriptor passed to getSocketInfoIfRunning");
PR_SetError(PR_BAD_DESCRIPTOR_ERROR, 0);
return nullptr;
}
NSSSocketControl* socketInfo = (NSSSocketControl*)fd->secret;
if (socketInfo->IsCanceled()) {
PRErrorCode err = socketInfo->GetErrorCode();
PR_SetError(err, 0);
if (op == reading || op == writing) {
// We must do TLS intolerance checks for reads and writes, for timeouts
// in particular.
(void)checkHandshake(-1, op == reading, fd, socketInfo);
}
// If we get here, it is probably because cert verification failed and this
// is the first I/O attempt since that failure.
return nullptr;
}
return socketInfo;
}
} // namespace
static PRStatus nsSSLIOLayerConnect(PRFileDesc* fd, const PRNetAddr* addr,
PRIntervalTime timeout) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] connecting SSL socket\n", (void*)fd));
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) return PR_FAILURE;
PRStatus status = fd->lower->methods->connect(fd->lower, addr, timeout);
if (status != PR_SUCCESS) {
MOZ_LOG(gPIPNSSLog, LogLevel::Error,
("[%p] Lower layer connect error: %d\n", (void*)fd, PR_GetError()));
return status;
}
MOZ_LOG(gPIPNSSLog, LogLevel::Debug, ("[%p] Connect\n", (void*)fd));
return status;
}
void nsSSLIOLayerHelpers::rememberTolerantAtVersion(const nsACString& hostName,
int16_t port,
uint16_t tolerant) {
nsCString key;
getSiteKey(hostName, port, key);
MutexAutoLock lock(mutex);
IntoleranceEntry entry;
if (mTLSIntoleranceInfo.Get(key, &entry)) {
entry.AssertInvariant();
entry.tolerant = std::max(entry.tolerant, tolerant);
if (entry.intolerant != 0 && entry.intolerant <= entry.tolerant) {
entry.intolerant = entry.tolerant + 1;
entry.intoleranceReason = 0; // lose the reason
}
} else {
entry.tolerant = tolerant;
entry.intolerant = 0;
entry.intoleranceReason = 0;
}
entry.AssertInvariant();
mTLSIntoleranceInfo.InsertOrUpdate(key, entry);
}
void nsSSLIOLayerHelpers::forgetIntolerance(const nsACString& hostName,
int16_t port) {
nsCString key;
getSiteKey(hostName, port, key);
MutexAutoLock lock(mutex);
IntoleranceEntry entry;
if (mTLSIntoleranceInfo.Get(key, &entry)) {
entry.AssertInvariant();
entry.intolerant = 0;
entry.intoleranceReason = 0;
entry.AssertInvariant();
mTLSIntoleranceInfo.InsertOrUpdate(key, entry);
}
}
bool nsSSLIOLayerHelpers::fallbackLimitReached(const nsACString& hostName,
uint16_t intolerant) {
if (isInsecureFallbackSite(hostName)) {
return intolerant <= SSL_LIBRARY_VERSION_TLS_1_0;
}
return intolerant <= mVersionFallbackLimit;
}
// returns true if we should retry the handshake
bool nsSSLIOLayerHelpers::rememberIntolerantAtVersion(
const nsACString& hostName, int16_t port, uint16_t minVersion,
uint16_t intolerant, PRErrorCode intoleranceReason) {
if (intolerant <= minVersion || fallbackLimitReached(hostName, intolerant)) {
// We can't fall back any further. Assume that intolerance isn't the issue.
forgetIntolerance(hostName, port);
return false;
}
nsCString key;
getSiteKey(hostName, port, key);
MutexAutoLock lock(mutex);
IntoleranceEntry entry;
if (mTLSIntoleranceInfo.Get(key, &entry)) {
entry.AssertInvariant();
if (intolerant <= entry.tolerant) {
// We already know the server is tolerant at an equal or higher version.
return false;
}
if ((entry.intolerant != 0 && intolerant >= entry.intolerant)) {
// We already know that the server is intolerant at a lower version.
return true;
}
} else {
entry.tolerant = 0;
}
entry.intolerant = intolerant;
entry.intoleranceReason = intoleranceReason;
entry.AssertInvariant();
mTLSIntoleranceInfo.InsertOrUpdate(key, entry);
return true;
}
void nsSSLIOLayerHelpers::adjustForTLSIntolerance(
const nsACString& hostName, int16_t port,
/*in/out*/ SSLVersionRange& range) {
IntoleranceEntry entry;
{
nsCString key;
getSiteKey(hostName, port, key);
MutexAutoLock lock(mutex);
if (!mTLSIntoleranceInfo.Get(key, &entry)) {
return;
}
}
entry.AssertInvariant();
if (entry.intolerant != 0) {
// We've tried connecting at a higher range but failed, so try at the
// version we haven't tried yet, unless we have reached the minimum.
if (range.min < entry.intolerant) {
range.max = entry.intolerant - 1;
}
}
}
PRErrorCode nsSSLIOLayerHelpers::getIntoleranceReason(
const nsACString& hostName, int16_t port) {
IntoleranceEntry entry;
{
nsCString key;
getSiteKey(hostName, port, key);
MutexAutoLock lock(mutex);
if (!mTLSIntoleranceInfo.Get(key, &entry)) {
return 0;
}
}
entry.AssertInvariant();
return entry.intoleranceReason;
}
bool nsSSLIOLayerHelpers::nsSSLIOLayerInitialized = false;
PRDescIdentity nsSSLIOLayerHelpers::nsSSLIOLayerIdentity;
PRDescIdentity nsSSLIOLayerHelpers::nsSSLPlaintextLayerIdentity;
PRIOMethods nsSSLIOLayerHelpers::nsSSLIOLayerMethods;
PRIOMethods nsSSLIOLayerHelpers::nsSSLPlaintextLayerMethods;
static PRStatus nsSSLIOLayerClose(PRFileDesc* fd) {
if (!fd) return PR_FAILURE;
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] Shutting down socket\n", (void*)fd));
NSSSocketControl* socketInfo = (NSSSocketControl*)fd->secret;
MOZ_ASSERT(socketInfo, "NSSSocketControl was null for an fd");
return socketInfo->CloseSocketAndDestroy();
}
#if defined(DEBUG_SSL_VERBOSE) && defined(DUMP_BUFFER)
// Dumps a (potentially binary) buffer using SSM_DEBUG. (We could have used
// the version in ssltrace.c, but that's specifically tailored to SSLTRACE.)
# define DUMPBUF_LINESIZE 24
static void nsDumpBuffer(unsigned char* buf, int len) {
char hexbuf[DUMPBUF_LINESIZE * 3 + 1];
char chrbuf[DUMPBUF_LINESIZE + 1];
static const char* hex = "0123456789abcdef";
int i = 0;
int l = 0;
char ch;
char* c;
char* h;
if (len == 0) return;
hexbuf[DUMPBUF_LINESIZE * 3] = '\0';
chrbuf[DUMPBUF_LINESIZE] = '\0';
(void)memset(hexbuf, 0x20, DUMPBUF_LINESIZE * 3);
(void)memset(chrbuf, 0x20, DUMPBUF_LINESIZE);
h = hexbuf;
c = chrbuf;
while (i < len) {
ch = buf[i];
if (l == DUMPBUF_LINESIZE) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug, ("%s%s\n", hexbuf, chrbuf));
(void)memset(hexbuf, 0x20, DUMPBUF_LINESIZE * 3);
(void)memset(chrbuf, 0x20, DUMPBUF_LINESIZE);
h = hexbuf;
c = chrbuf;
l = 0;
}
// Convert a character to hex.
*h++ = hex[(ch >> 4) & 0xf];
*h++ = hex[ch & 0xf];
h++;
// Put the character (if it's printable) into the character buffer.
if ((ch >= 0x20) && (ch <= 0x7e)) {
*c++ = ch;
} else {
*c++ = '.';
}
i++;
l++;
}
MOZ_LOG(gPIPNSSLog, LogLevel::Debug, ("%s%s\n", hexbuf, chrbuf));
}
# define DEBUG_DUMP_BUFFER(buf, len) nsDumpBuffer(buf, len)
#else
# define DEBUG_DUMP_BUFFER(buf, len)
#endif
namespace {
uint32_t tlsIntoleranceTelemetryBucket(PRErrorCode err) {
// returns a numeric code for where we track various errors in telemetry
// only errors that cause version fallback are tracked,
// so this is also used to determine which errors can cause version fallback
switch (err) {
case SSL_ERROR_BAD_MAC_ALERT:
return 1;
case SSL_ERROR_BAD_MAC_READ:
return 2;
case SSL_ERROR_HANDSHAKE_FAILURE_ALERT:
return 3;
case SSL_ERROR_HANDSHAKE_UNEXPECTED_ALERT:
return 4;
case SSL_ERROR_ILLEGAL_PARAMETER_ALERT:
return 6;
case SSL_ERROR_NO_CYPHER_OVERLAP:
return 7;
case SSL_ERROR_UNSUPPORTED_VERSION:
return 10;
case SSL_ERROR_PROTOCOL_VERSION_ALERT:
return 11;
case SSL_ERROR_BAD_HANDSHAKE_HASH_VALUE:
return 13;
case SSL_ERROR_DECODE_ERROR_ALERT:
return 14;
case PR_CONNECT_RESET_ERROR:
return 16;
case PR_END_OF_FILE_ERROR:
return 17;
case SSL_ERROR_INTERNAL_ERROR_ALERT:
return 18;
default:
return 0;
}
}
bool retryDueToTLSIntolerance(PRErrorCode err, NSSSocketControl* socketInfo) {
// This function is supposed to decide which error codes should
// be used to conclude server is TLS intolerant.
// Note this only happens during the initial SSL handshake.
if (StaticPrefs::security_tls_ech_disable_grease_on_fallback() &&
socketInfo->GetEchExtensionStatus() == EchExtensionStatus::kGREASE) {
// Don't record any intolerances if we used ECH GREASE but force a retry.
return true;
}
SSLVersionRange range = socketInfo->GetTLSVersionRange();
nsSSLIOLayerHelpers& helpers = socketInfo->SharedState().IOLayerHelpers();
if (err == SSL_ERROR_UNSUPPORTED_VERSION &&
range.min == SSL_LIBRARY_VERSION_TLS_1_0) {
socketInfo->SetSecurityState(nsIWebProgressListener::STATE_IS_INSECURE |
nsIWebProgressListener::STATE_USES_SSL_3);
}
// NSS will return SSL_ERROR_RX_MALFORMED_SERVER_HELLO if anti-downgrade
// detected the downgrade.
if (err == SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT ||
err == SSL_ERROR_RX_MALFORMED_SERVER_HELLO) {
// This is a clear signal that we've fallen back too many versions. Treat
// this as a hard failure, but forget any intolerance so that later attempts
// don't use this version (i.e., range.max) and trigger the error again.
// First, track the original cause of the version fallback. This uses the
// same buckets as the telemetry below, except that bucket 0 will include
// all cases where there wasn't an original reason.
PRErrorCode originalReason = helpers.getIntoleranceReason(
socketInfo->GetHostName(), socketInfo->GetPort());
Telemetry::Accumulate(Telemetry::SSL_VERSION_FALLBACK_INAPPROPRIATE,
tlsIntoleranceTelemetryBucket(originalReason));
helpers.forgetIntolerance(socketInfo->GetHostName(), socketInfo->GetPort());
return false;
}
// When not using a proxy we'll see a connection reset error.
// When using a proxy, we'll see an end of file error.
// Don't allow STARTTLS connections to fall back on connection resets or
// EOF.
if ((err == PR_CONNECT_RESET_ERROR || err == PR_END_OF_FILE_ERROR) &&
socketInfo->GetForSTARTTLS()) {
return false;
}
uint32_t reason = tlsIntoleranceTelemetryBucket(err);
if (reason == 0) {
return false;
}
Telemetry::HistogramID pre;
Telemetry::HistogramID post;
switch (range.max) {
case SSL_LIBRARY_VERSION_TLS_1_3:
pre = Telemetry::SSL_TLS13_INTOLERANCE_REASON_PRE;
post = Telemetry::SSL_TLS13_INTOLERANCE_REASON_POST;
break;
case SSL_LIBRARY_VERSION_TLS_1_2:
pre = Telemetry::SSL_TLS12_INTOLERANCE_REASON_PRE;
post = Telemetry::SSL_TLS12_INTOLERANCE_REASON_POST;
break;
case SSL_LIBRARY_VERSION_TLS_1_1:
pre = Telemetry::SSL_TLS11_INTOLERANCE_REASON_PRE;
post = Telemetry::SSL_TLS11_INTOLERANCE_REASON_POST;
break;
case SSL_LIBRARY_VERSION_TLS_1_0:
pre = Telemetry::SSL_TLS10_INTOLERANCE_REASON_PRE;
post = Telemetry::SSL_TLS10_INTOLERANCE_REASON_POST;
break;
default:
MOZ_CRASH("impossible TLS version");
return false;
}
// The difference between _PRE and _POST represents how often we avoided
// TLS intolerance fallback due to remembered tolerance.
Telemetry::Accumulate(pre, reason);
if (!helpers.rememberIntolerantAtVersion(socketInfo->GetHostName(),
socketInfo->GetPort(), range.min,
range.max, err)) {
return false;
}
Telemetry::Accumulate(post, reason);
return true;
}
// Ensure that we haven't added too many errors to fit.
static_assert((SSL_ERROR_END_OF_LIST - SSL_ERROR_BASE) <= 256,
"too many SSL errors");
static_assert((SEC_ERROR_END_OF_LIST - SEC_ERROR_BASE) <= 256,
"too many SEC errors");
static_assert((PR_MAX_ERROR - PR_NSPR_ERROR_BASE) <= 128,
"too many NSPR errors");
static_assert((mozilla::pkix::ERROR_BASE - mozilla::pkix::END_OF_LIST) < 31,
"too many moz::pkix errors");
static void reportHandshakeResult(int32_t bytesTransferred, bool wasReading,
PRErrorCode err,
NSSSocketControl* socketInfo) {
uint32_t bucket;
// A negative bytesTransferred or a 0 read are errors.
if (bytesTransferred > 0) {
bucket = 0;
} else if ((bytesTransferred == 0) && !wasReading) {
// PR_Write() is defined to never return 0, but let's make sure.
MOZ_ASSERT(false);
bucket = 671;
} else if (IS_SSL_ERROR(err)) {
bucket = err - SSL_ERROR_BASE;
MOZ_ASSERT(bucket > 0); // SSL_ERROR_EXPORT_ONLY_SERVER isn't used.
} else if (IS_SEC_ERROR(err)) {
bucket = (err - SEC_ERROR_BASE) + 256;
} else if ((err >= PR_NSPR_ERROR_BASE) && (err < PR_MAX_ERROR)) {
bucket = (err - PR_NSPR_ERROR_BASE) + 512;
} else if ((err >= mozilla::pkix::ERROR_BASE) &&
(err < mozilla::pkix::ERROR_LIMIT)) {
bucket = (err - mozilla::pkix::ERROR_BASE) + 640;
} else {
bucket = 671;
}
uint32_t flags = socketInfo->GetProviderFlags();
if (!(flags & nsISocketProvider::IS_RETRY)) {
Telemetry::Accumulate(Telemetry::SSL_HANDSHAKE_RESULT_FIRST_TRY, bucket);
}
if (flags & nsISocketProvider::BE_CONSERVATIVE) {
Telemetry::Accumulate(Telemetry::SSL_HANDSHAKE_RESULT_CONSERVATIVE, bucket);
}
switch (socketInfo->GetEchExtensionStatus()) {
case EchExtensionStatus::kGREASE:
Telemetry::Accumulate(Telemetry::SSL_HANDSHAKE_RESULT_ECH_GREASE, bucket);
break;
case EchExtensionStatus::kReal:
Telemetry::Accumulate(Telemetry::SSL_HANDSHAKE_RESULT_ECH, bucket);
break;
default:
break;
}
Telemetry::Accumulate(Telemetry::SSL_HANDSHAKE_RESULT, bucket);
if (bucket == 0) {
nsCOMPtr<nsITransportSecurityInfo> securityInfo;
if (NS_FAILED(socketInfo->GetSecurityInfo(getter_AddRefs(securityInfo))) ||
!securityInfo) {
return;
}
// Web Privacy Telemetry for successful connections.
bool success = true;
bool usedPrivateDNS = false;
success &= securityInfo->GetUsedPrivateDNS(&usedPrivateDNS) == NS_OK;
bool madeOCSPRequest = false;
success &= securityInfo->GetMadeOCSPRequests(&madeOCSPRequest) == NS_OK;
uint16_t protocolVersion = 0;
success &= securityInfo->GetProtocolVersion(&protocolVersion) == NS_OK;
bool usedTLS13 = protocolVersion == 4;
bool usedECH = false;
success &= securityInfo->GetIsAcceptedEch(&usedECH) == NS_OK;
// As bucket is 0 we are reporting the results of a sucessful connection
// and so TransportSecurityInfo should be populated. However, this isn't
// happening in all cases, see Bug 1789458.
if (success) {
uint8_t TLSPrivacyResult = 0;
TLSPrivacyResult |= usedTLS13 << 0;
TLSPrivacyResult |= !madeOCSPRequest << 1;
TLSPrivacyResult |= usedPrivateDNS << 2;
TLSPrivacyResult |= usedECH << 3;
Telemetry::Accumulate(Telemetry::SSL_HANDSHAKE_PRIVACY, TLSPrivacyResult);
}
}
}
// Check the status of the handshake. This is where PSM checks for TLS
// intolerance and potentially sets up TLS intolerance fallback by noting the
// intolerance, setting the NSPR error to PR_CONNECT_RESET_ERROR, and returning
// -1 as the bytes transferred so that necko retries the connection.
// Otherwise, PSM returns the bytes transferred unchanged.
int32_t checkHandshake(int32_t bytesTransferred, bool wasReading,
PRFileDesc* ssl_layer_fd, NSSSocketControl* socketInfo) {
const PRErrorCode originalError = PR_GetError();
// If the connection would block, return early.
if (bytesTransferred < 0 && originalError == PR_WOULD_BLOCK_ERROR) {
PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
return bytesTransferred;
}
// We only need to do TLS intolerance checking for the first transfer.
bool handleHandshakeResultNow = socketInfo->IsHandshakePending();
if (!handleHandshakeResultNow) {
// If we've encountered an error since the handshake, ensure the socket
// control is cancelled, so that getSocketInfoIfRunning will correctly
// cause us to fail if another part of Gecko (erroneously) calls an I/O
// function (PR_Send/PR_Recv/etc.) again on this socket.
if (bytesTransferred < 0) {
if (!socketInfo->IsCanceled()) {
socketInfo->SetCanceled(originalError);
}
PR_SetError(originalError, 0);
}
return bytesTransferred;
}
// TLS intolerant servers only cause the first transfer to fail, so let's
// set the HandshakePending attribute to false so that we don't try this logic
// again in a subsequent transfer.
socketInfo->SetHandshakeNotPending();
// Report the result once for each handshake. Note that this does not
// get handshakes which are cancelled before any reads or writes
// happen.
reportHandshakeResult(bytesTransferred, wasReading, originalError,
socketInfo);
// If there was no error, return early. The case where we read 0 bytes is not
// considered an error by NSS, but PSM interprets this as TLS intolerance, so
// we turn it into an error. Writes of 0 bytes are an error, because PR_Write
// is never supposed to return 0.
if (bytesTransferred > 0) {
return bytesTransferred;
}
// There was some sort of error. Determine what it was and if we want to
// retry the connection due to TLS intolerance.
PRErrorCode errorToUse = originalError;
// Turn zero-length reads into errors and handle zero-length write errors.
if (bytesTransferred == 0) {
if (wasReading) {
errorToUse = PR_END_OF_FILE_ERROR;
} else {
errorToUse = SEC_ERROR_LIBRARY_FAILURE;
}
bytesTransferred = -1;
}
bool wantRetry = retryDueToTLSIntolerance(errorToUse, socketInfo);
// Set the error on the socket control and cancel it.
if (!socketInfo->IsCanceled()) {
socketInfo->SetCanceled(errorToUse);
}
if (wantRetry) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] checkHandshake: will retry with lower max TLS version",
ssl_layer_fd));
// Setting the error PR_CONNECT_RESET_ERROR causes necko to retry the
// connection.
PR_SetError(PR_CONNECT_RESET_ERROR, 0);
} else {
PR_SetError(originalError, 0);
}
return bytesTransferred;
}
} // namespace
static int16_t nsSSLIOLayerPoll(PRFileDesc* fd, int16_t in_flags,
int16_t* out_flags) {
if (!out_flags) {
NS_WARNING("nsSSLIOLayerPoll called with null out_flags");
return 0;
}
*out_flags = 0;
NSSSocketControl* socketInfo =
getSocketInfoIfRunning(fd, not_reading_or_writing);
if (!socketInfo) {
// If we get here, it is probably because certificate validation failed
// and this is the first I/O operation after the failure.
MOZ_LOG(
gPIPNSSLog, LogLevel::Debug,
("[%p] polling SSL socket right after certificate verification failed "
"or NSS shutdown or SDR logout %d\n",
fd, (int)in_flags));
MOZ_ASSERT(in_flags & PR_POLL_EXCEPT,
"Caller did not poll for EXCEPT (canceled)");
// Since this poll method cannot return errors, we want the caller to call
// PR_Send/PR_Recv right away to get the error, so we tell that we are
// ready for whatever I/O they are asking for. (See getSocketInfoIfRunning).
*out_flags = in_flags | PR_POLL_EXCEPT; // see also bug 480619
return in_flags;
}
MOZ_LOG(gPIPNSSLog, LogLevel::Verbose,
(socketInfo->IsWaitingForCertVerification()
? "[%p] polling SSL socket during certificate verification "
"using lower %d\n"
: "[%p] poll SSL socket using lower %d\n",
fd, (int)in_flags));
// We want the handshake to continue during certificate validation, so we
// don't need to do anything special here. libssl automatically blocks when
// it reaches any point that would be unsafe to send/receive something before
// cert validation is complete.
int16_t result = fd->lower->methods->poll(fd->lower, in_flags, out_flags);
MOZ_LOG(gPIPNSSLog, LogLevel::Verbose,
("[%p] poll SSL socket returned %d\n", (void*)fd, (int)result));
return result;
}
nsSSLIOLayerHelpers::nsSSLIOLayerHelpers(uint32_t aTlsFlags)
: mTreatUnsafeNegotiationAsBroken(false),
mTLSIntoleranceInfo(),
mVersionFallbackLimit(SSL_LIBRARY_VERSION_TLS_1_0),
mutex("nsSSLIOLayerHelpers.mutex"),
mTlsFlags(aTlsFlags) {}
// PSMAvailable and PSMAvailable64 are reachable, but they're unimplemented in
// PSM, so we set an error and return -1.
static int32_t PSMAvailable(PRFileDesc*) {
PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
return -1;
}
static int64_t PSMAvailable64(PRFileDesc*) {
PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
return -1;
}
static PRStatus PSMGetsockname(PRFileDesc* fd, PRNetAddr* addr) {
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) return PR_FAILURE;
return fd->lower->methods->getsockname(fd->lower, addr);
}
static PRStatus PSMGetpeername(PRFileDesc* fd, PRNetAddr* addr) {
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) return PR_FAILURE;
return fd->lower->methods->getpeername(fd->lower, addr);
}
static PRStatus PSMGetsocketoption(PRFileDesc* fd, PRSocketOptionData* data) {
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) return PR_FAILURE;
return fd->lower->methods->getsocketoption(fd, data);
}
static PRStatus PSMSetsocketoption(PRFileDesc* fd,
const PRSocketOptionData* data) {
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) return PR_FAILURE;
return fd->lower->methods->setsocketoption(fd, data);
}
static int32_t PSMRecv(PRFileDesc* fd, void* buf, int32_t amount, int flags,
PRIntervalTime timeout) {
NSSSocketControl* socketInfo = getSocketInfoIfRunning(fd, reading);
if (!socketInfo) return -1;
if (flags != PR_MSG_PEEK && flags != 0) {
PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
return -1;
}
int32_t bytesRead =
fd->lower->methods->recv(fd->lower, buf, amount, flags, timeout);
MOZ_LOG(gPIPNSSLog, LogLevel::Verbose,
("[%p] read %d bytes\n", (void*)fd, bytesRead));
#ifdef DEBUG_SSL_VERBOSE
DEBUG_DUMP_BUFFER((unsigned char*)buf, bytesRead);
#endif
return checkHandshake(bytesRead, true, fd, socketInfo);
}
static int32_t PSMSend(PRFileDesc* fd, const void* buf, int32_t amount,
int flags, PRIntervalTime timeout) {
NSSSocketControl* socketInfo = getSocketInfoIfRunning(fd, writing);
if (!socketInfo) return -1;
if (flags != 0) {
PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
return -1;
}
#ifdef DEBUG_SSL_VERBOSE
DEBUG_DUMP_BUFFER((unsigned char*)buf, amount);
#endif
if (socketInfo->IsShortWritePending() && amount > 0) {
// We got "SSL short write" last time, try to flush the pending byte.
#ifdef DEBUG
socketInfo->CheckShortWrittenBuffer(static_cast<const unsigned char*>(buf),
amount);
#endif
buf = socketInfo->GetShortWritePendingByteRef();
amount = 1;
MOZ_LOG(gPIPNSSLog, LogLevel::Verbose,
("[%p] pushing 1 byte after SSL short write", fd));
}
int32_t bytesWritten =
fd->lower->methods->send(fd->lower, buf, amount, flags, timeout);
// NSS indicates that it can't write all requested data (due to network
// congestion, for example) by returning either one less than the amount
// of data requested or 16383, if the requested amount is greater than
// 16384. We refer to this as a "short write". If we simply returned
// the amount that NSS did write, the layer above us would then call
// PSMSend with a very small amount of data (often 1). This is inefficient
// and can lead to alternating between sending large packets and very small
// packets. To prevent this, we alert the layer calling us that the operation
// would block and that it should be retried later, with the same data.
// When it does, we tell NSS to write the remaining byte it didn't write
// in the previous call. We then return the total number of bytes written,
// which is the number that caused the short write plus the additional byte
// we just wrote out.
// The 16384 value is based on libssl's maximum buffer size:
// MAX_FRAGMENT_LENGTH - 1
//
// It's in a private header, though, filed bug 1394822 to expose it.
static const int32_t kShortWrite16k = 16383;
if ((amount > 1 && bytesWritten == (amount - 1)) ||
(amount > kShortWrite16k && bytesWritten == kShortWrite16k)) {
// This is indication of an "SSL short write", block to force retry.
socketInfo->SetShortWritePending(
bytesWritten + 1, // The amount to return after the flush
*(static_cast<const unsigned char*>(buf) + bytesWritten));
MOZ_LOG(
gPIPNSSLog, LogLevel::Verbose,
("[%p] indicated SSL short write for %d bytes (written just %d bytes)",
fd, amount, bytesWritten));
bytesWritten = -1;
PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
#ifdef DEBUG
socketInfo->RememberShortWrittenBuffer(
static_cast<const unsigned char*>(buf));
#endif
} else if (socketInfo->IsShortWritePending() && bytesWritten == 1) {
// We have now flushed all pending data in the SSL socket
// after the indicated short write. Tell the upper layer
// it has sent all its data now.
MOZ_LOG(gPIPNSSLog, LogLevel::Verbose,
("[%p] finished SSL short write", fd));
bytesWritten = socketInfo->ResetShortWritePending();
}
MOZ_LOG(gPIPNSSLog, LogLevel::Verbose,
("[%p] wrote %d bytes\n", fd, bytesWritten));
return checkHandshake(bytesWritten, false, fd, socketInfo);
}
static PRStatus PSMBind(PRFileDesc* fd, const PRNetAddr* addr) {
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) return PR_FAILURE;
return fd->lower->methods->bind(fd->lower, addr);
}
static int32_t nsSSLIOLayerRead(PRFileDesc* fd, void* buf, int32_t amount) {
return PSMRecv(fd, buf, amount, 0, PR_INTERVAL_NO_TIMEOUT);
}
static int32_t nsSSLIOLayerWrite(PRFileDesc* fd, const void* buf,
int32_t amount) {
return PSMSend(fd, buf, amount, 0, PR_INTERVAL_NO_TIMEOUT);
}
static PRStatus PSMConnectcontinue(PRFileDesc* fd, int16_t out_flags) {
if (!getSocketInfoIfRunning(fd, not_reading_or_writing)) {
return PR_FAILURE;
}
return fd->lower->methods->connectcontinue(fd, out_flags);
}
namespace {
class PrefObserver : public nsIObserver {
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIOBSERVER
explicit PrefObserver(nsSSLIOLayerHelpers* aOwner) : mOwner(aOwner) {}
protected:
virtual ~PrefObserver() = default;
private:
nsSSLIOLayerHelpers* mOwner;
};
} // unnamed namespace
NS_IMPL_ISUPPORTS(PrefObserver, nsIObserver)
NS_IMETHODIMP
PrefObserver::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* someData) {
if (nsCRT::strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) == 0) {
NS_ConvertUTF16toUTF8 prefName(someData);
if (prefName.EqualsLiteral(
"security.ssl.treat_unsafe_negotiation_as_broken")) {
bool enabled;
Preferences::GetBool("security.ssl.treat_unsafe_negotiation_as_broken",
&enabled);
mOwner->setTreatUnsafeNegotiationAsBroken(enabled);
} else if (prefName.EqualsLiteral("security.tls.version.fallback-limit")) {
mOwner->loadVersionFallbackLimit();
} else if (prefName.EqualsLiteral("security.tls.insecure_fallback_hosts")) {
// Changes to the allowlist on the public side will update the pref.
// Don't propagate the changes to the private side.
if (mOwner->isPublic()) {
mOwner->initInsecureFallbackSites();
}
}
}
return NS_OK;
}
static int32_t PlaintextRecv(PRFileDesc* fd, void* buf, int32_t amount,
int flags, PRIntervalTime timeout) {
// The shutdownlocker is not needed here because it will already be
// held higher in the stack
NSSSocketControl* socketInfo = nullptr;
int32_t bytesRead =
fd->lower->methods->recv(fd->lower, buf, amount, flags, timeout);
if (fd->identity == nsSSLIOLayerHelpers::nsSSLPlaintextLayerIdentity)
socketInfo = (NSSSocketControl*)fd->secret;
if ((bytesRead > 0) && socketInfo)
socketInfo->AddPlaintextBytesRead(bytesRead);
return bytesRead;
}
nsSSLIOLayerHelpers::~nsSSLIOLayerHelpers() {
// mPrefObserver will only be set if this->Init was called. The GTest tests
// do not call Init.
if (mPrefObserver) {
Preferences::RemoveObserver(
mPrefObserver, "security.ssl.treat_unsafe_negotiation_as_broken");
Preferences::RemoveObserver(mPrefObserver,
"security.tls.version.fallback-limit");
Preferences::RemoveObserver(mPrefObserver,
"security.tls.insecure_fallback_hosts");
}
}
template <typename R, R return_value, typename... Args>
static R InvalidPRIOMethod(Args...) {
MOZ_ASSERT_UNREACHABLE("I/O method is invalid");
PR_SetError(PR_NOT_IMPLEMENTED_ERROR, 0);
return return_value;
}
nsresult nsSSLIOLayerHelpers::Init() {
if (!nsSSLIOLayerInitialized) {
MOZ_ASSERT(NS_IsMainThread());
nsSSLIOLayerInitialized = true;
nsSSLIOLayerIdentity = PR_GetUniqueIdentity("NSS layer");
nsSSLIOLayerMethods = *PR_GetDefaultIOMethods();
nsSSLIOLayerMethods.fsync =
InvalidPRIOMethod<PRStatus, PR_FAILURE, PRFileDesc*>;
nsSSLIOLayerMethods.seek =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, int32_t, PRSeekWhence>;
nsSSLIOLayerMethods.seek64 =
InvalidPRIOMethod<int64_t, -1, PRFileDesc*, int64_t, PRSeekWhence>;
nsSSLIOLayerMethods.fileInfo =
InvalidPRIOMethod<PRStatus, PR_FAILURE, PRFileDesc*, PRFileInfo*>;
nsSSLIOLayerMethods.fileInfo64 =
InvalidPRIOMethod<PRStatus, PR_FAILURE, PRFileDesc*, PRFileInfo64*>;
nsSSLIOLayerMethods.writev =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, const PRIOVec*, int32_t,
PRIntervalTime>;
nsSSLIOLayerMethods.accept =
InvalidPRIOMethod<PRFileDesc*, nullptr, PRFileDesc*, PRNetAddr*,
PRIntervalTime>;
nsSSLIOLayerMethods.listen =
InvalidPRIOMethod<PRStatus, PR_FAILURE, PRFileDesc*, int>;
nsSSLIOLayerMethods.shutdown =
InvalidPRIOMethod<PRStatus, PR_FAILURE, PRFileDesc*, int>;
nsSSLIOLayerMethods.recvfrom =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, void*, int32_t, int,
PRNetAddr*, PRIntervalTime>;
nsSSLIOLayerMethods.sendto =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, const void*, int32_t, int,
const PRNetAddr*, PRIntervalTime>;
nsSSLIOLayerMethods.acceptread =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, PRFileDesc**, PRNetAddr**,
void*, int32_t, PRIntervalTime>;
nsSSLIOLayerMethods.transmitfile =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, PRFileDesc*, const void*,
int32_t, PRTransmitFileFlags, PRIntervalTime>;
nsSSLIOLayerMethods.sendfile =
InvalidPRIOMethod<int32_t, -1, PRFileDesc*, PRSendFileData*,
PRTransmitFileFlags, PRIntervalTime>;
nsSSLIOLayerMethods.available = PSMAvailable;
nsSSLIOLayerMethods.available64 = PSMAvailable64;
nsSSLIOLayerMethods.getsockname = PSMGetsockname;
nsSSLIOLayerMethods.getpeername = PSMGetpeername;
nsSSLIOLayerMethods.getsocketoption = PSMGetsocketoption;
nsSSLIOLayerMethods.setsocketoption = PSMSetsocketoption;
nsSSLIOLayerMethods.recv = PSMRecv;
nsSSLIOLayerMethods.send = PSMSend;
nsSSLIOLayerMethods.connectcontinue = PSMConnectcontinue;
nsSSLIOLayerMethods.bind = PSMBind;
nsSSLIOLayerMethods.connect = nsSSLIOLayerConnect;
nsSSLIOLayerMethods.close = nsSSLIOLayerClose;
nsSSLIOLayerMethods.write = nsSSLIOLayerWrite;
nsSSLIOLayerMethods.read = nsSSLIOLayerRead;
nsSSLIOLayerMethods.poll = nsSSLIOLayerPoll;
nsSSLPlaintextLayerIdentity = PR_GetUniqueIdentity("Plaintxext PSM layer");
nsSSLPlaintextLayerMethods = *PR_GetDefaultIOMethods();
nsSSLPlaintextLayerMethods.recv = PlaintextRecv;
}
loadVersionFallbackLimit();
// non main thread helpers will need to use defaults
if (NS_IsMainThread()) {
bool enabled = false;
Preferences::GetBool("security.ssl.treat_unsafe_negotiation_as_broken",
&enabled);
setTreatUnsafeNegotiationAsBroken(enabled);
initInsecureFallbackSites();
mPrefObserver = new PrefObserver(this);
Preferences::AddStrongObserver(
mPrefObserver, "security.ssl.treat_unsafe_negotiation_as_broken");
Preferences::AddStrongObserver(mPrefObserver,
"security.tls.version.fallback-limit");
Preferences::AddStrongObserver(mPrefObserver,
"security.tls.insecure_fallback_hosts");
} else {
MOZ_ASSERT(mTlsFlags, "Only per socket version can ignore prefs");
}
return NS_OK;
}
void nsSSLIOLayerHelpers::loadVersionFallbackLimit() {
// see nsNSSComponent::SetEnabledTLSVersions for pref handling rules
uint32_t limit = 3; // TLS 1.2
if (NS_IsMainThread()) {
limit = Preferences::GetUint("security.tls.version.fallback-limit",
3); // 3 = TLS 1.2
}
// set fallback limit if it is set in the tls flags
uint32_t tlsFlagsFallbackLimit = getTLSProviderFlagFallbackLimit(mTlsFlags);
if (tlsFlagsFallbackLimit) {
limit = tlsFlagsFallbackLimit;
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("loadVersionFallbackLimit overriden by tlsFlags %d\n", limit));
}
SSLVersionRange defaults = {SSL_LIBRARY_VERSION_TLS_1_2,
SSL_LIBRARY_VERSION_TLS_1_2};
SSLVersionRange filledInRange;
nsNSSComponent::FillTLSVersionRange(filledInRange, limit, limit, defaults);
if (filledInRange.max < SSL_LIBRARY_VERSION_TLS_1_2) {
filledInRange.max = SSL_LIBRARY_VERSION_TLS_1_2;
}
mVersionFallbackLimit = filledInRange.max;
}
void nsSSLIOLayerHelpers::clearStoredData() {
MOZ_ASSERT(NS_IsMainThread());
initInsecureFallbackSites();
MutexAutoLock lock(mutex);
mTLSIntoleranceInfo.Clear();
}
void nsSSLIOLayerHelpers::setInsecureFallbackSites(const nsCString& str) {
MutexAutoLock lock(mutex);
mInsecureFallbackSites.Clear();
for (const nsACString& host : nsCCharSeparatedTokenizer(str, ',').ToRange()) {
if (!host.IsEmpty()) {
mInsecureFallbackSites.PutEntry(host);
}
}
}
void nsSSLIOLayerHelpers::initInsecureFallbackSites() {
MOZ_ASSERT(NS_IsMainThread());
nsAutoCString insecureFallbackHosts;
Preferences::GetCString("security.tls.insecure_fallback_hosts",
insecureFallbackHosts);
setInsecureFallbackSites(insecureFallbackHosts);
}
bool nsSSLIOLayerHelpers::isPublic() const {
return this == &PublicSSLState()->IOLayerHelpers();
}
class FallbackPrefRemover final : public Runnable {
public:
explicit FallbackPrefRemover(const nsACString& aHost)
: mozilla::Runnable("FallbackPrefRemover"), mHost(aHost) {}
NS_IMETHOD Run() override;
private:
nsCString mHost;
};
NS_IMETHODIMP
FallbackPrefRemover::Run() {
MOZ_ASSERT(NS_IsMainThread());
nsAutoCString oldValue;
Preferences::GetCString("security.tls.insecure_fallback_hosts", oldValue);
nsCString newValue;
for (const nsACString& host :
nsCCharSeparatedTokenizer(oldValue, ',').ToRange()) {
if (host.Equals(mHost)) {
continue;
}
if (!newValue.IsEmpty()) {
newValue.Append(',');
}
newValue.Append(host);
}
Preferences::SetCString("security.tls.insecure_fallback_hosts", newValue);
return NS_OK;
}
void nsSSLIOLayerHelpers::removeInsecureFallbackSite(const nsACString& hostname,
uint16_t port) {
forgetIntolerance(hostname, port);
{
MutexAutoLock lock(mutex);
if (!mInsecureFallbackSites.Contains(hostname)) {
return;
}
mInsecureFallbackSites.RemoveEntry(hostname);
}
if (!isPublic()) {
return;
}
RefPtr<Runnable> runnable = new FallbackPrefRemover(hostname);
if (NS_IsMainThread()) {
runnable->Run();
} else {
NS_DispatchToMainThread(runnable);
}
}
bool nsSSLIOLayerHelpers::isInsecureFallbackSite(const nsACString& hostname) {
MutexAutoLock lock(mutex);
return mInsecureFallbackSites.Contains(hostname);
}
void nsSSLIOLayerHelpers::setTreatUnsafeNegotiationAsBroken(bool broken) {
MutexAutoLock lock(mutex);
mTreatUnsafeNegotiationAsBroken = broken;
}
bool nsSSLIOLayerHelpers::treatUnsafeNegotiationAsBroken() {
MutexAutoLock lock(mutex);
return mTreatUnsafeNegotiationAsBroken;
}
nsresult nsSSLIOLayerNewSocket(int32_t family, const char* host, int32_t port,
nsIProxyInfo* proxy,
const OriginAttributes& originAttributes,
PRFileDesc** fd,
nsITLSSocketControl** tlsSocketControl,
bool forSTARTTLS, uint32_t flags,
uint32_t tlsFlags) {
PRFileDesc* sock = PR_OpenTCPSocket(family);
if (!sock) return NS_ERROR_OUT_OF_MEMORY;
nsresult rv =
nsSSLIOLayerAddToSocket(family, host, port, proxy, originAttributes, sock,
tlsSocketControl, forSTARTTLS, flags, tlsFlags);
if (NS_FAILED(rv)) {
PR_Close(sock);
return rv;
}
*fd = sock;
return NS_OK;
}
static PRFileDesc* nsSSLIOLayerImportFD(PRFileDesc* fd,
NSSSocketControl* infoObject,
const char* host, bool haveHTTPSProxy) {
PRFileDesc* sslSock = SSL_ImportFD(nullptr, fd);
if (!sslSock) {
MOZ_ASSERT_UNREACHABLE("NSS: Error importing socket");
return nullptr;
}
SSL_SetPKCS11PinArg(sslSock, (nsIInterfaceRequestor*)infoObject);
SSL_HandshakeCallback(sslSock, HandshakeCallback, infoObject);
SSL_SetCanFalseStartCallback(sslSock, CanFalseStartCallback, infoObject);
// Disable this hook if we connect anonymously. See bug 466080.
uint32_t flags = 0;
infoObject->GetProviderFlags(&flags);
// Provide the client cert to HTTPS proxy no matter if it is anonymous.
if (flags & nsISocketProvider::ANONYMOUS_CONNECT && !haveHTTPSProxy &&
!(flags & nsISocketProvider::ANONYMOUS_CONNECT_ALLOW_CLIENT_CERT)) {
SSL_GetClientAuthDataHook(sslSock, nullptr, infoObject);
} else {
SSL_GetClientAuthDataHook(sslSock, SSLGetClientAuthDataHook, infoObject);
}
if (SECSuccess !=
SSL_AuthCertificateHook(sslSock, AuthCertificateHook, infoObject)) {
MOZ_ASSERT_UNREACHABLE("Failed to configure AuthCertificateHook");
goto loser;
}
if (SECSuccess != SSL_SetURL(sslSock, host)) {
MOZ_ASSERT_UNREACHABLE("SSL_SetURL failed");
goto loser;
}
return sslSock;
loser:
if (sslSock) {
PR_Close(sslSock);
}
return nullptr;
}
// Please change getSignatureName in nsNSSCallbacks.cpp when changing the list
// here. See NOTE at SSL_SignatureSchemePrefSet call site.
static const SSLSignatureScheme sEnabledSignatureSchemes[] = {
ssl_sig_ecdsa_secp256r1_sha256,
ssl_sig_ecdsa_secp384r1_sha384,
ssl_sig_ecdsa_secp521r1_sha512,
ssl_sig_rsa_pss_sha256,
ssl_sig_rsa_pss_sha384,
ssl_sig_rsa_pss_sha512,
ssl_sig_rsa_pkcs1_sha256,
ssl_sig_rsa_pkcs1_sha384,
ssl_sig_rsa_pkcs1_sha512,
#if !defined(EARLY_BETA_OR_EARLIER)
ssl_sig_ecdsa_sha1,
#endif
ssl_sig_rsa_pkcs1_sha1,
};
static nsresult nsSSLIOLayerSetOptions(PRFileDesc* fd, bool forSTARTTLS,
bool haveProxy, const char* host,
int32_t port,
NSSSocketControl* infoObject) {
if (forSTARTTLS || haveProxy) {
if (SECSuccess != SSL_OptionSet(fd, SSL_SECURITY, false)) {
return NS_ERROR_FAILURE;
}
}
SSLVersionRange range;
if (SSL_VersionRangeGet(fd, &range) != SECSuccess) {
return NS_ERROR_FAILURE;
}
// Set TLS 1.3 compat mode.
if (SECSuccess != SSL_OptionSet(fd, SSL_ENABLE_TLS13_COMPAT_MODE, PR_TRUE)) {
MOZ_LOG(gPIPNSSLog, LogLevel::Error,
("[%p] nsSSLIOLayerSetOptions: Setting compat mode failed\n", fd));
}
// setting TLS max version
uint32_t versionFlags =
getTLSProviderFlagMaxVersion(infoObject->GetProviderTlsFlags());
if (versionFlags) {
MOZ_LOG(
gPIPNSSLog, LogLevel::Debug,
("[%p] nsSSLIOLayerSetOptions: version flags %d\n", fd, versionFlags));
if (versionFlags == kTLSProviderFlagMaxVersion10) {
range.max = SSL_LIBRARY_VERSION_TLS_1_0;
} else if (versionFlags == kTLSProviderFlagMaxVersion11) {
range.max = SSL_LIBRARY_VERSION_TLS_1_1;
} else if (versionFlags == kTLSProviderFlagMaxVersion12) {
range.max = SSL_LIBRARY_VERSION_TLS_1_2;
} else if (versionFlags == kTLSProviderFlagMaxVersion13) {
range.max = SSL_LIBRARY_VERSION_TLS_1_3;
} else {
MOZ_LOG(gPIPNSSLog, LogLevel::Error,
("[%p] nsSSLIOLayerSetOptions: unknown version flags %d\n", fd,
versionFlags));
}
}
if ((infoObject->GetProviderFlags() & nsISocketProvider::BE_CONSERVATIVE) &&
(range.max > SSL_LIBRARY_VERSION_TLS_1_2)) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] nsSSLIOLayerSetOptions: range.max limited to 1.2 due to "
"BE_CONSERVATIVE flag\n",
fd));
range.max = SSL_LIBRARY_VERSION_TLS_1_2;
}
uint16_t maxEnabledVersion = range.max;
infoObject->SharedState().IOLayerHelpers().adjustForTLSIntolerance(
infoObject->GetHostName(), infoObject->GetPort(), range);
MOZ_LOG(
gPIPNSSLog, LogLevel::Debug,
("[%p] nsSSLIOLayerSetOptions: using TLS version range (0x%04x,0x%04x)\n",
fd, static_cast<unsigned int>(range.min),
static_cast<unsigned int>(range.max)));
// If the user has set their minimum version to something higher than what
// we've now set the maximum to, this will result in an inconsistent version
// range unless we fix it up. This will override their preference, but we only
// do this for sites critical to the operation of the browser (e.g. update
// servers) and telemetry experiments.
if (range.min > range.max) {
range.min = range.max;
}
if (SSL_VersionRangeSet(fd, &range) != SECSuccess) {
return NS_ERROR_FAILURE;
}
infoObject->SetTLSVersionRange(range);
// when adjustForTLSIntolerance tweaks the maximum version downward,
// we tell the server using this SCSV so they can detect a downgrade attack
if (range.max < maxEnabledVersion) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] nsSSLIOLayerSetOptions: enabling TLS_FALLBACK_SCSV\n", fd));
// Some servers will choke if we send the fallback SCSV with TLS 1.2.
if (range.max < SSL_LIBRARY_VERSION_TLS_1_2) {
if (SECSuccess != SSL_OptionSet(fd, SSL_ENABLE_FALLBACK_SCSV, true)) {
return NS_ERROR_FAILURE;
}
}
// tell NSS the max enabled version to make anti-downgrade effective
if (SECSuccess != SSL_SetDowngradeCheckVersion(fd, maxEnabledVersion)) {
return NS_ERROR_FAILURE;
}
}
// Enable ECH GREASE if suitable. Has no impact if 'real' ECH is being used.
if (range.max >= SSL_LIBRARY_VERSION_TLS_1_3 &&
!(infoObject->GetProviderFlags() & (nsISocketProvider::BE_CONSERVATIVE |
nsISocketTransport::DONT_TRY_ECH)) &&
StaticPrefs::security_tls_ech_grease_probability()) {
if ((RandomUint64().valueOr(0) % 100) >=
100 - StaticPrefs::security_tls_ech_grease_probability()) {
MOZ_LOG(gPIPNSSLog, LogLevel::Debug,
("[%p] nsSSLIOLayerSetOptions: enabling TLS ECH Grease\n", fd));
if (SECSuccess != SSL_EnableTls13GreaseEch(fd, PR_TRUE)) {
return NS_ERROR_FAILURE;
}
// ECH Padding can be between 1 and 255
if (SECSuccess !=
SSL_SetTls13GreaseEchSize(
fd, std::clamp(StaticPrefs::security_tls_ech_grease_size(), 1U,
255U))) {
return NS_ERROR_FAILURE;
}
infoObject->UpdateEchExtensionStatus(EchExtensionStatus::kGREASE);
}
}
// Include a modest set of named groups.
// Please change getKeaGroupName in nsNSSCallbacks.cpp when changing the list
// here.
const SSLNamedGroup namedGroups[] = {
ssl_grp_ec_curve25519, ssl_grp_ec_secp256r1, ssl_grp_ec_secp384r1,
ssl_grp_ec_secp521r1, ssl_grp_ffdhe_2048, ssl_grp_ffdhe_3072};
if (SECSuccess != SSL_NamedGroupConfig(fd, namedGroups,
mozilla::ArrayLength(namedGroups))) {
return NS_ERROR_FAILURE;
}
// This ensures that we send key shares for X25519 and P-256 in TLS 1.3, so
// that servers are less likely to use HelloRetryRequest.
if (SECSuccess != SSL_SendAdditionalKeyShares(fd, 1)) {
return NS_ERROR_FAILURE;
}
// NOTE: Should this list ever include ssl_sig_rsa_pss_pss_sha* (or should
// it become possible to enable this scheme via a pref), it is required
// to test that a Delegated Credential containing a small-modulus RSA-PSS SPKI
// is properly rejected. NSS will not advertise PKCS1 or RSAE schemes (which
// the |ssl_sig_rsa_pss_*| defines alias, meaning we will not currently accept
// any RSA DC.
if (SECSuccess != SSL_SignatureSchemePrefSet(
fd, sEnabledSignatureSchemes,
mozilla::ArrayLength(sEnabledSignatureSchemes))) {
return NS_ERROR_FAILURE;
}
bool enabled = infoObject->SharedState().IsOCSPStaplingEnabled();
if (SECSuccess != SSL_OptionSet(fd, SSL_ENABLE_OCSP_STAPLING, enabled)) {
return NS_ERROR_FAILURE;
}
bool sctsEnabled = infoObject->SharedState().IsSignedCertTimestampsEnabled();
if (SECSuccess !=
SSL_OptionSet(fd, SSL_ENABLE_SIGNED_CERT_TIMESTAMPS, sctsEnabled)) {
return NS_ERROR_FAILURE;
}
if (SECSuccess != SSL_OptionSet(fd, SSL_HANDSHAKE_AS_CLIENT, true)) {
return NS_ERROR_FAILURE;
}
#if defined(__arm__) && not defined(__ARM_FEATURE_CRYPTO)
unsigned int enabledCiphers = 0;
std::vector<uint16_t> ciphers(SSL_GetNumImplementedCiphers());
// Returns only the enabled (reflecting prefs) ciphers, ordered
// by their occurence in
if (SSL_CipherSuiteOrderGet(fd, ciphers.data(), &enabledCiphers) !=
SECSuccess) {
return NS_ERROR_FAILURE;
}
// On ARM, prefer (TLS_CHACHA20_POLY1305_SHA256) over AES when hardware
// support for AES isn't available. However, it may be disabled. If enabled,
// it will either be element [0] or [1]*. If [0], we're done. If [1], swap it
// with [0] (TLS_AES_128_GCM_SHA256).
// *(assuming the compile-time order remains unchanged)
if (enabledCiphers > 1) {
if (ciphers[0] != TLS_CHACHA20_POLY1305_SHA256 &&
ciphers[1] == TLS_CHACHA20_POLY1305_SHA256) {
std::swap(ciphers[0], ciphers[1]);
if (SSL_CipherSuiteOrderSet(fd, ciphers.data(), enabledCiphers) !=
SECSuccess) {
return NS_ERROR_FAILURE;
}
}
}
#endif
// Set the Peer ID so that SSL proxy connections work properly and to
// separate anonymous and/or private browsing connections.
nsAutoCString peerId;
infoObject->GetPeerId(peerId);
if (SECSuccess != SSL_SetSockPeerID(fd, peerId.get())) {
return NS_ERROR_FAILURE;
}
uint32_t flags = infoObject->GetProviderFlags();
if (flags & nsISocketProvider::NO_PERMANENT_STORAGE) {
if (SECSuccess != SSL_OptionSet(fd, SSL_ENABLE_SESSION_TICKETS, false) ||
SECSuccess != SSL_OptionSet(fd, SSL_NO_CACHE, true)) {
return NS_ERROR_FAILURE;
}
}
return NS_OK;
}
SECStatus StoreResumptionToken(PRFileDesc* fd, const PRUint8* resumptionToken,
unsigned int len, void* ctx) {
PRIntn val;
if (SSL_OptionGet(fd, SSL_ENABLE_SESSION_TICKETS, &val) != SECSuccess ||
val == 0) {
return SECFailure;
}
NSSSocketControl* infoObject = (NSSSocketControl*)ctx;
if (!infoObject) {
return SECFailure;
}
nsAutoCString peerId;
infoObject->GetPeerId(peerId);
if (NS_FAILED(
net::SSLTokensCache::Put(peerId, resumptionToken, len, infoObject))) {
return SECFailure;
}
return SECSuccess;
}
nsresult nsSSLIOLayerAddToSocket(int32_t family, const char* host, int32_t port,
nsIProxyInfo* proxy,
const OriginAttributes& originAttributes,
PRFileDesc* fd,
nsITLSSocketControl** tlsSocketControl,
bool forSTARTTLS, uint32_t providerFlags,
uint32_t providerTlsFlags) {
PRFileDesc* layer = nullptr;
PRFileDesc* plaintextLayer = nullptr;
nsresult rv;
PRStatus stat;
SharedSSLState* sharedState = nullptr;
RefPtr<SharedSSLState> allocatedState;
if (providerTlsFlags) {
allocatedState = new SharedSSLState(providerTlsFlags);
sharedState = allocatedState.get();
} else {
bool isPrivate = providerFlags & nsISocketProvider::NO_PERMANENT_STORAGE ||
originAttributes.mPrivateBrowsingId !=
OriginAttributes().mPrivateBrowsingId;
sharedState = isPrivate ? PrivateSSLState() : PublicSSLState();
}
NSSSocketControl* infoObject =
new NSSSocketControl(nsDependentCString(host), port, *sharedState,
providerFlags, providerTlsFlags);
if (!infoObject) return NS_ERROR_FAILURE;
NS_ADDREF(infoObject);
infoObject->SetForSTARTTLS(forSTARTTLS);
infoObject->SetOriginAttributes(originAttributes);
if (allocatedState) {
infoObject->SetSharedOwningReference(allocatedState);
}
bool haveProxy = false;
bool haveHTTPSProxy = false;
if (proxy) {
nsAutoCString proxyHost;
proxy->GetHost(proxyHost);
haveProxy = !proxyHost.IsEmpty();
nsAutoCString type;
haveHTTPSProxy = haveProxy && NS_SUCCEEDED(proxy->GetType(type)) &&
type.EqualsLiteral("https");
}
// A plaintext observer shim is inserted so we can observe some protocol
// details without modifying nss
plaintextLayer =
PR_CreateIOLayerStub(nsSSLIOLayerHelpers::nsSSLPlaintextLayerIdentity,
&nsSSLIOLayerHelpers::nsSSLPlaintextLayerMethods);
if (plaintextLayer) {
plaintextLayer->secret = (PRFilePrivate*)infoObject;
stat = PR_PushIOLayer(fd, PR_TOP_IO_LAYER, plaintextLayer);
if (stat == PR_FAILURE) {
plaintextLayer->dtor(plaintextLayer);
plaintextLayer = nullptr;
}
}
PRFileDesc* sslSock =
nsSSLIOLayerImportFD(fd, infoObject, host, haveHTTPSProxy);
if (!sslSock) {
MOZ_ASSERT_UNREACHABLE("NSS: Error importing socket");
goto loser;
}
infoObject->SetFileDescPtr(sslSock);
rv = nsSSLIOLayerSetOptions(sslSock, forSTARTTLS, haveProxy, host, port,
infoObject);
if (NS_FAILED(rv)) goto loser;
// Now, layer ourselves on top of the SSL socket...
layer = PR_CreateIOLayerStub(nsSSLIOLayerHelpers::nsSSLIOLayerIdentity,
&nsSSLIOLayerHelpers::nsSSLIOLayerMethods);
if (!layer) goto loser;
layer->secret = (PRFilePrivate*)infoObject;
stat = PR_PushIOLayer(sslSock, PR_GetLayersIdentity(sslSock), layer);
if (stat == PR_FAILURE) {
goto loser;
}
MOZ_LOG(gPIPNSSLog, LogLevel::Debug, ("[%p] Socket set up", (void*)sslSock));
*tlsSocketControl = do_AddRef(infoObject).take();
// We are going use a clear connection first //
if (forSTARTTLS || haveProxy) {
infoObject->SetHandshakeNotPending();
}
infoObject->SharedState().NoteSocketCreated();
rv = infoObject->SetResumptionTokenFromExternalCache();
if (NS_FAILED(rv)) {
return rv;
}
SSL_SetResumptionTokenCallback(sslSock, &StoreResumptionToken, infoObject);
return NS_OK;
loser:
NS_IF_RELEASE(infoObject);
if (layer) {
layer->dtor(layer);
}
if (plaintextLayer) {
// Note that PR_*IOLayer operations may modify the stack of fds, so a
// previously-valid pointer may no longer point to what we think it points
// to after calling PR_PopIOLayer. We must operate on the pointer returned
// by PR_PopIOLayer.
plaintextLayer =
PR_PopIOLayer(fd, nsSSLIOLayerHelpers::nsSSLPlaintextLayerIdentity);
plaintextLayer->dtor(plaintextLayer);
}
return NS_ERROR_FAILURE;
}
already_AddRefed<IPCClientCertsChild> GetIPCClientCertsActor() {
PBackgroundChild* backgroundActor =
BackgroundChild::GetOrCreateForSocketParentBridgeForCurrentThread();
if (!backgroundActor) {
return nullptr;
}
RefPtr<PIPCClientCertsChild> actor =
SingleManagedOrNull(backgroundActor->ManagedPIPCClientCertsChild());
if (!actor) {
actor = backgroundActor->SendPIPCClientCertsConstructor(
new IPCClientCertsChild());
if (!actor) {
return nullptr;
}
}
return actor.forget().downcast<IPCClientCertsChild>();
}
extern "C" {
const uint8_t kIPCClientCertsObjectTypeCert = 1;
const uint8_t kIPCClientCertsObjectTypeRSAKey = 2;
const uint8_t kIPCClientCertsObjectTypeECKey = 3;
// This function is provided to the IPC client certs module so it can cause the
// parent process to find certificates and keys and send identifying
// information about them over IPC.
void DoFindObjects(FindObjectsCallback cb, void* ctx) {
RefPtr<IPCClientCertsChild> ipcClientCertsActor(GetIPCClientCertsActor());
if (!ipcClientCertsActor) {
return;
}
nsTArray<IPCClientCertObject> objects;
if (!ipcClientCertsActor->SendFindObjects(&objects)) {
return;
}
for (const auto& object : objects) {
switch (object.type()) {
case IPCClientCertObject::TECKey:
cb(kIPCClientCertsObjectTypeECKey, object.get_ECKey().params().Length(),
object.get_ECKey().params().Elements(),
object.get_ECKey().cert().Length(),
object.get_ECKey().cert().Elements(), object.get_ECKey().slotType(),
ctx);
break;
case IPCClientCertObject::TRSAKey:
cb(kIPCClientCertsObjectTypeRSAKey,
object.get_RSAKey().modulus().Length(),
object.get_RSAKey().modulus().Elements(),
object.get_RSAKey().cert().Length(),
object.get_RSAKey().cert().Elements(),
object.get_RSAKey().slotType(), ctx);
break;
case IPCClientCertObject::TCertificate:
cb(kIPCClientCertsObjectTypeCert,
object.get_Certificate().der().Length(),
object.get_Certificate().der().Elements(), 0, nullptr,
object.get_Certificate().slotType(), ctx);
break;
default:
MOZ_ASSERT_UNREACHABLE("unhandled IPCClientCertObject type");
break;
}
}
}
// This function is provided to the IPC client certs module so it can cause the
// parent process to sign the given data using the key corresponding to the
// given certificate, using the given parameters.
void DoSign(size_t cert_len, const uint8_t* cert, size_t data_len,
const uint8_t* data, size_t params_len, const uint8_t* params,