/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/openssl_stream_adapter.h"
#include <openssl/bio.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/tls1.h>
#include <openssl/x509v3.h>
#include "absl/strings/string_view.h"
#ifndef OPENSSL_IS_BORINGSSL
#include <openssl/dtls1.h>
#include <openssl/ssl.h>
#endif
#include <atomic>
#include <memory>
#include <utility>
#include <vector>
#include "api/array_view.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "rtc_base/openssl.h"
#include "rtc_base/openssl_adapter.h"
#include "rtc_base/openssl_digest.h"
#ifdef OPENSSL_IS_BORINGSSL
#include "rtc_base/boringssl_identity.h"
#else
#include "rtc_base/openssl_identity.h"
#endif
#include "rtc_base/openssl_utility.h"
#include "rtc_base/ssl_certificate.h"
#include "rtc_base/stream.h"
#include "rtc_base/string_encode.h"
#include "rtc_base/thread.h"
#include "rtc_base/time_utils.h"
#include "system_wrappers/include/field_trial.h"
#if (OPENSSL_VERSION_NUMBER < 0x10100000L)
#error "webrtc requires at least OpenSSL version 1.1.0, to support DTLS-SRTP"
#endif
// Defines for the TLS Cipher Suite Map.
#define DEFINE_CIPHER_ENTRY_SSL3(name) \
{ SSL3_CK_##name, "TLS_" #name }
#define DEFINE_CIPHER_ENTRY_TLS1(name) \
{ TLS1_CK_##name, "TLS_" #name }
namespace rtc {
namespace {
using ::webrtc::SafeTask;
// SRTP cipher suite table. `internal_name` is used to construct a
// colon-separated profile strings which is needed by
// SSL_CTX_set_tlsext_use_srtp().
struct SrtpCipherMapEntry {
const char* internal_name;
const int id;
};
// Cipher name table. Maps internal OpenSSL cipher ids to the RFC name.
struct SslCipherMapEntry {
uint32_t openssl_id;
const char* rfc_name;
};
// This isn't elegant, but it's better than an external reference
constexpr SrtpCipherMapEntry kSrtpCipherMap[] = {
{"SRTP_AES128_CM_SHA1_80", kSrtpAes128CmSha1_80},
{"SRTP_AES128_CM_SHA1_32", kSrtpAes128CmSha1_32},
{"SRTP_AEAD_AES_128_GCM", kSrtpAeadAes128Gcm},
{"SRTP_AEAD_AES_256_GCM", kSrtpAeadAes256Gcm}};
#ifndef OPENSSL_IS_BORINGSSL
// The "SSL_CIPHER_standard_name" function is only available in OpenSSL when
// compiled with tracing, so we need to define the mapping manually here.
constexpr SslCipherMapEntry kSslCipherMap[] = {
// TLS v1.0 ciphersuites from RFC2246.
DEFINE_CIPHER_ENTRY_SSL3(RSA_RC4_128_SHA),
{SSL3_CK_RSA_DES_192_CBC3_SHA, "TLS_RSA_WITH_3DES_EDE_CBC_SHA"},
// AES ciphersuites from RFC3268.
{TLS1_CK_RSA_WITH_AES_128_SHA, "TLS_RSA_WITH_AES_128_CBC_SHA"},
{TLS1_CK_DHE_RSA_WITH_AES_128_SHA, "TLS_DHE_RSA_WITH_AES_128_CBC_SHA"},
{TLS1_CK_RSA_WITH_AES_256_SHA, "TLS_RSA_WITH_AES_256_CBC_SHA"},
{TLS1_CK_DHE_RSA_WITH_AES_256_SHA, "TLS_DHE_RSA_WITH_AES_256_CBC_SHA"},
// ECC ciphersuites from RFC4492.
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_RC4_128_SHA),
{TLS1_CK_ECDHE_ECDSA_WITH_DES_192_CBC3_SHA,
"TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA"},
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_128_CBC_SHA),
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_256_CBC_SHA),
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_RC4_128_SHA),
{TLS1_CK_ECDHE_RSA_WITH_DES_192_CBC3_SHA,
"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA"},
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_128_CBC_SHA),
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_256_CBC_SHA),
// TLS v1.2 ciphersuites.
{TLS1_CK_RSA_WITH_AES_128_SHA256, "TLS_RSA_WITH_AES_128_CBC_SHA256"},
{TLS1_CK_RSA_WITH_AES_256_SHA256, "TLS_RSA_WITH_AES_256_CBC_SHA256"},
{TLS1_CK_DHE_RSA_WITH_AES_128_SHA256,
"TLS_DHE_RSA_WITH_AES_128_CBC_SHA256"},
{TLS1_CK_DHE_RSA_WITH_AES_256_SHA256,
"TLS_DHE_RSA_WITH_AES_256_CBC_SHA256"},
// TLS v1.2 GCM ciphersuites from RFC5288.
DEFINE_CIPHER_ENTRY_TLS1(RSA_WITH_AES_128_GCM_SHA256),
DEFINE_CIPHER_ENTRY_TLS1(RSA_WITH_AES_256_GCM_SHA384),
DEFINE_CIPHER_ENTRY_TLS1(DHE_RSA_WITH_AES_128_GCM_SHA256),
DEFINE_CIPHER_ENTRY_TLS1(DHE_RSA_WITH_AES_256_GCM_SHA384),
DEFINE_CIPHER_ENTRY_TLS1(DH_RSA_WITH_AES_128_GCM_SHA256),
DEFINE_CIPHER_ENTRY_TLS1(DH_RSA_WITH_AES_256_GCM_SHA384),
// ECDH HMAC based ciphersuites from RFC5289.
{TLS1_CK_ECDHE_ECDSA_WITH_AES_128_SHA256,
"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256"},
{TLS1_CK_ECDHE_ECDSA_WITH_AES_256_SHA384,
"TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384"},
{TLS1_CK_ECDHE_RSA_WITH_AES_128_SHA256,
"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256"},
{TLS1_CK_ECDHE_RSA_WITH_AES_256_SHA384,
"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384"},
// ECDH GCM based ciphersuites from RFC5289.
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_128_GCM_SHA256),
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_ECDSA_WITH_AES_256_GCM_SHA384),
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_128_GCM_SHA256),
DEFINE_CIPHER_ENTRY_TLS1(ECDHE_RSA_WITH_AES_256_GCM_SHA384),
{0, nullptr}};
#endif // #ifndef OPENSSL_IS_BORINGSSL
#ifdef OPENSSL_IS_BORINGSSL
// Enabled by EnableTimeCallbackForTesting. Should never be set in production
// code.
bool g_use_time_callback_for_testing = false;
// Not used in production code. Actual time should be relative to Jan 1, 1970.
void TimeCallbackForTesting(const SSL* ssl, struct timeval* out_clock) {
int64_t time = TimeNanos();
out_clock->tv_sec = time / kNumNanosecsPerSec;
out_clock->tv_usec = (time % kNumNanosecsPerSec) / kNumNanosecsPerMicrosec;
}
#endif
} // namespace
//////////////////////////////////////////////////////////////////////
// StreamBIO
//////////////////////////////////////////////////////////////////////
static int stream_write(BIO* h, const char* buf, int num);
static int stream_read(BIO* h, char* buf, int size);
static int stream_puts(BIO* h, const char* str);
static long stream_ctrl(BIO* h, int cmd, long arg1, void* arg2);
static int stream_new(BIO* h);
static int stream_free(BIO* data);
static BIO_METHOD* BIO_stream_method() {
static BIO_METHOD* method = [] {
BIO_METHOD* method = BIO_meth_new(BIO_TYPE_BIO, "stream");
BIO_meth_set_write(method, stream_write);
BIO_meth_set_read(method, stream_read);
BIO_meth_set_puts(method, stream_puts);
BIO_meth_set_ctrl(method, stream_ctrl);
BIO_meth_set_create(method, stream_new);
BIO_meth_set_destroy(method, stream_free);
return method;
}();
return method;
}
static BIO* BIO_new_stream(StreamInterface* stream) {
BIO* ret = BIO_new(BIO_stream_method());
if (ret == nullptr) {
return nullptr;
}
BIO_set_data(ret, stream);
return ret;
}
// bio methods return 1 (or at least non-zero) on success and 0 on failure.
static int stream_new(BIO* b) {
BIO_set_shutdown(b, 0);
BIO_set_init(b, 1);
BIO_set_data(b, 0);
return 1;
}
static int stream_free(BIO* b) {
if (b == nullptr) {
return 0;
}
return 1;
}
static int stream_read(BIO* b, char* out, int outl) {
if (!out) {
return -1;
}
StreamInterface* stream = static_cast<StreamInterface*>(BIO_get_data(b));
BIO_clear_retry_flags(b);
size_t read;
int error;
StreamResult result = stream->Read(
rtc::MakeArrayView(reinterpret_cast<uint8_t*>(out), outl), read, error);
if (result == SR_SUCCESS) {
return checked_cast<int>(read);
} else if (result == SR_BLOCK) {
BIO_set_retry_read(b);
}
return -1;
}
static int stream_write(BIO* b, const char* in, int inl) {
if (!in) {
return -1;
}
StreamInterface* stream = static_cast<StreamInterface*>(BIO_get_data(b));
BIO_clear_retry_flags(b);
size_t written;
int error;
StreamResult result = stream->Write(
rtc::MakeArrayView(reinterpret_cast<const uint8_t*>(in), inl), written,
error);
if (result == SR_SUCCESS) {
return checked_cast<int>(written);
} else if (result == SR_BLOCK) {
BIO_set_retry_write(b);
}
return -1;
}
static int stream_puts(BIO* b, const char* str) {
return stream_write(b, str, checked_cast<int>(strlen(str)));
}
static long stream_ctrl(BIO* b, int cmd, long num, void* ptr) {
switch (cmd) {
case BIO_CTRL_RESET:
return 0;
case BIO_CTRL_EOF: {
StreamInterface* stream = static_cast<StreamInterface*>(ptr);
// 1 means end-of-stream.
return (stream->GetState() == SS_CLOSED) ? 1 : 0;
}
case BIO_CTRL_WPENDING:
case BIO_CTRL_PENDING:
return 0;
case BIO_CTRL_FLUSH:
return 1;
case BIO_CTRL_DGRAM_QUERY_MTU:
// openssl defaults to mtu=256 unless we return something here.
// The handshake doesn't actually need to send packets above 1k,
// so this seems like a sensible value that should work in most cases.
// Webrtc uses the same value for video packets.
return 1200;
default:
return 0;
}
}
/////////////////////////////////////////////////////////////////////////////
// OpenSSLStreamAdapter
/////////////////////////////////////////////////////////////////////////////
static std::atomic<bool> g_use_legacy_tls_protocols_override(false);
static std::atomic<bool> g_allow_legacy_tls_protocols(false);
void SetAllowLegacyTLSProtocols(const absl::optional<bool>& allow) {
g_use_legacy_tls_protocols_override.store(allow.has_value());
if (allow.has_value())
g_allow_legacy_tls_protocols.store(allow.value());
}
bool ShouldAllowLegacyTLSProtocols() {
return g_use_legacy_tls_protocols_override.load()
? g_allow_legacy_tls_protocols.load()
: webrtc::field_trial::IsEnabled("WebRTC-LegacyTlsProtocols");
}
OpenSSLStreamAdapter::OpenSSLStreamAdapter(
std::unique_ptr<StreamInterface> stream)
: stream_(std::move(stream)),
owner_(rtc::Thread::Current()),
state_(SSL_NONE),
role_(SSL_CLIENT),
ssl_read_needs_write_(false),
ssl_write_needs_read_(false),
ssl_(nullptr),
ssl_ctx_(nullptr),
ssl_mode_(SSL_MODE_TLS),
ssl_max_version_(SSL_PROTOCOL_TLS_12),
// Default is to support legacy TLS protocols.
// This will be changed to default non-support in M82 or M83.
support_legacy_tls_protocols_flag_(ShouldAllowLegacyTLSProtocols()) {
stream_->SignalEvent.connect(this, &OpenSSLStreamAdapter::OnEvent);
}
OpenSSLStreamAdapter::~OpenSSLStreamAdapter() {
timeout_task_.Stop();
Cleanup(0);
}
void OpenSSLStreamAdapter::SetIdentity(std::unique_ptr<SSLIdentity> identity) {
RTC_DCHECK(!identity_);
#ifdef OPENSSL_IS_BORINGSSL
identity_.reset(static_cast<BoringSSLIdentity*>(identity.release()));
#else
identity_.reset(static_cast<OpenSSLIdentity*>(identity.release()));
#endif
}
SSLIdentity* OpenSSLStreamAdapter::GetIdentityForTesting() const {
return identity_.get();
}
void OpenSSLStreamAdapter::SetServerRole(SSLRole role) {
role_ = role;
}
bool OpenSSLStreamAdapter::SetPeerCertificateDigest(
absl::string_view digest_alg,
const unsigned char* digest_val,
size_t digest_len,
SSLPeerCertificateDigestError* error) {
RTC_DCHECK(!peer_certificate_verified_);
RTC_DCHECK(!HasPeerCertificateDigest());
size_t expected_len;
if (error) {
*error = SSLPeerCertificateDigestError::NONE;
}
if (!OpenSSLDigest::GetDigestSize(digest_alg, &expected_len)) {
RTC_LOG(LS_WARNING) << "Unknown digest algorithm: " << digest_alg;
if (error) {
*error = SSLPeerCertificateDigestError::UNKNOWN_ALGORITHM;
}
return false;
}
if (expected_len != digest_len) {
if (error) {
*error = SSLPeerCertificateDigestError::INVALID_LENGTH;
}
return false;
}
peer_certificate_digest_value_.SetData(digest_val, digest_len);
peer_certificate_digest_algorithm_ = std::string(digest_alg);
if (!peer_cert_chain_) {
// Normal case, where the digest is set before we obtain the certificate
// from the handshake.
return true;
}
if (!VerifyPeerCertificate()) {
Error("SetPeerCertificateDigest", -1, SSL_AD_BAD_CERTIFICATE, false);
if (error) {
*error = SSLPeerCertificateDigestError::VERIFICATION_FAILED;
}
return false;
}
if (state_ == SSL_CONNECTED) {
// Post the event asynchronously to unwind the stack. The caller
// of ContinueSSL may be the same object listening for these
// events and may not be prepared for reentrancy.
PostEvent(SE_OPEN | SE_READ | SE_WRITE, 0);
}
return true;
}
std::string OpenSSLStreamAdapter::SslCipherSuiteToName(int cipher_suite) {
#ifdef OPENSSL_IS_BORINGSSL
const SSL_CIPHER* ssl_cipher = SSL_get_cipher_by_value(cipher_suite);
if (!ssl_cipher) {
return std::string();
}
return SSL_CIPHER_standard_name(ssl_cipher);
#else
const int openssl_cipher_id = 0x03000000L | cipher_suite;
for (const SslCipherMapEntry* entry = kSslCipherMap; entry->rfc_name;
++entry) {
if (openssl_cipher_id == static_cast<int>(entry->openssl_id)) {
return entry->rfc_name;
}
}
return std::string();
#endif
}
bool OpenSSLStreamAdapter::GetSslCipherSuite(int* cipher_suite) {
if (state_ != SSL_CONNECTED) {
return false;
}
const SSL_CIPHER* current_cipher = SSL_get_current_cipher(ssl_);
if (current_cipher == nullptr) {
return false;
}
*cipher_suite = static_cast<uint16_t>(SSL_CIPHER_get_id(current_cipher));
return true;
}
SSLProtocolVersion OpenSSLStreamAdapter::GetSslVersion() const {
if (state_ != SSL_CONNECTED) {
return SSL_PROTOCOL_NOT_GIVEN;
}
int ssl_version = SSL_version(ssl_);
if (ssl_mode_ == SSL_MODE_DTLS) {
if (ssl_version == DTLS1_VERSION) {
return SSL_PROTOCOL_DTLS_10;
} else if (ssl_version == DTLS1_2_VERSION) {
return SSL_PROTOCOL_DTLS_12;
}
} else {
if (ssl_version == TLS1_VERSION) {
return SSL_PROTOCOL_TLS_10;
} else if (ssl_version == TLS1_1_VERSION) {
return SSL_PROTOCOL_TLS_11;
} else if (ssl_version == TLS1_2_VERSION) {
return SSL_PROTOCOL_TLS_12;
}
}
return SSL_PROTOCOL_NOT_GIVEN;
}
bool OpenSSLStreamAdapter::GetSslVersionBytes(int* version) const {
if (state_ != SSL_CONNECTED) {
return false;
}
*version = SSL_version(ssl_);
return true;
}
// Key Extractor interface
bool OpenSSLStreamAdapter::ExportKeyingMaterial(absl::string_view label,
const uint8_t* context,
size_t context_len,
bool use_context,
uint8_t* result,
size_t result_len) {
if (SSL_export_keying_material(ssl_, result, result_len, label.data(),
label.length(), context, context_len,
use_context) != 1) {
return false;
}
return true;
}
bool OpenSSLStreamAdapter::SetDtlsSrtpCryptoSuites(
const std::vector<int>& ciphers) {
if (state_ != SSL_NONE) {
return false;
}
std::string internal_ciphers;
for (const int cipher : ciphers) {
bool found = false;
for (const auto& entry : kSrtpCipherMap) {
if (cipher == entry.id) {
found = true;
if (!internal_ciphers.empty()) {
internal_ciphers += ":";
}
internal_ciphers += entry.internal_name;
break;
}
}
if (!found) {
RTC_LOG(LS_ERROR) << "Could not find cipher: " << cipher;
return false;
}
}
if (internal_ciphers.empty()) {
return false;
}
srtp_ciphers_ = internal_ciphers;
return true;
}
bool OpenSSLStreamAdapter::GetDtlsSrtpCryptoSuite(int* crypto_suite) {
RTC_DCHECK(state_ == SSL_CONNECTED);
if (state_ != SSL_CONNECTED) {
return false;
}
const SRTP_PROTECTION_PROFILE* srtp_profile =
SSL_get_selected_srtp_profile(ssl_);
if (!srtp_profile) {
return false;
}
*crypto_suite = srtp_profile->id;
RTC_DCHECK(!SrtpCryptoSuiteToName(*crypto_suite).empty());
return true;
}
bool OpenSSLStreamAdapter::IsTlsConnected() {
return state_ == SSL_CONNECTED;
}
int OpenSSLStreamAdapter::StartSSL() {
// Don't allow StartSSL to be called twice.
if (state_ != SSL_NONE) {
return -1;
}
if (stream_->GetState() != SS_OPEN) {
state_ = SSL_WAIT;
return 0;
}
state_ = SSL_CONNECTING;
if (int err = BeginSSL()) {
Error("BeginSSL", err, 0, false);
return err;
}
return 0;
}
void OpenSSLStreamAdapter::SetMode(SSLMode mode) {
RTC_DCHECK(state_ == SSL_NONE);
ssl_mode_ = mode;
}
void OpenSSLStreamAdapter::SetMaxProtocolVersion(SSLProtocolVersion version) {
RTC_DCHECK(ssl_ctx_ == nullptr);
ssl_max_version_ = version;
}
void OpenSSLStreamAdapter::SetInitialRetransmissionTimeout(int timeout_ms) {
RTC_DCHECK(ssl_ctx_ == nullptr);
dtls_handshake_timeout_ms_ = timeout_ms;
}
//
// StreamInterface Implementation
//
StreamResult OpenSSLStreamAdapter::Write(rtc::ArrayView<const uint8_t> data,
size_t& written,
int& error) {
RTC_DLOG(LS_VERBOSE) << "OpenSSLStreamAdapter::Write(" << data.size() << ")";
switch (state_) {
case SSL_NONE:
// pass-through in clear text
return stream_->Write(data, written, error);
case SSL_WAIT:
case SSL_CONNECTING:
return SR_BLOCK;
case SSL_CONNECTED:
if (WaitingToVerifyPeerCertificate()) {
return SR_BLOCK;
}
break;
case SSL_ERROR:
case SSL_CLOSED:
default:
error = ssl_error_code_;
return SR_ERROR;
}
// OpenSSL will return an error if we try to write zero bytes
if (data.size() == 0) {
written = 0;
return SR_SUCCESS;
}
ssl_write_needs_read_ = false;
int code = SSL_write(ssl_, data.data(), checked_cast<int>(data.size()));
int ssl_error = SSL_get_error(ssl_, code);
switch (ssl_error) {
case SSL_ERROR_NONE:
RTC_DLOG(LS_VERBOSE) << " -- success";
RTC_DCHECK_GT(code, 0);
RTC_DCHECK_LE(code, data.size());
written = code;
return SR_SUCCESS;
case SSL_ERROR_WANT_READ:
RTC_DLOG(LS_VERBOSE) << " -- error want read";
ssl_write_needs_read_ = true;
return SR_BLOCK;
case SSL_ERROR_WANT_WRITE:
RTC_DLOG(LS_VERBOSE) << " -- error want write";
return SR_BLOCK;
case SSL_ERROR_ZERO_RETURN:
default:
Error("SSL_write", (ssl_error ? ssl_error : -1), 0, false);
error = ssl_error_code_;
return SR_ERROR;
}
// not reached
}
StreamResult OpenSSLStreamAdapter::Read(rtc::ArrayView<uint8_t> data,
size_t& read,
int& error) {
RTC_DLOG(LS_VERBOSE) << "OpenSSLStreamAdapter::Read(" << data.size() << ")";
switch (state_) {
case SSL_NONE:
// pass-through in clear text
return stream_->Read(data, read, error);
case SSL_WAIT:
case SSL_CONNECTING:
return SR_BLOCK;
case SSL_CONNECTED:
if (WaitingToVerifyPeerCertificate()) {
return SR_BLOCK;
}
break;
case SSL_CLOSED:
return SR_EOS;
case SSL_ERROR:
default:
error = ssl_error_code_;
return SR_ERROR;
}
// Don't trust OpenSSL with zero byte reads
if (data.size() == 0) {
read = 0;
return SR_SUCCESS;
}
ssl_read_needs_write_ = false;
const int code = SSL_read(ssl_, data.data(), checked_cast<int>(data.size()));
const int ssl_error = SSL_get_error(ssl_, code);
switch (ssl_error) {
case SSL_ERROR_NONE:
RTC_DLOG(LS_VERBOSE) << " -- success";
RTC_DCHECK_GT(code, 0);
RTC_DCHECK_LE(code, data.size());
read = code;
if (ssl_mode_ == SSL_MODE_DTLS) {
// Enforce atomic reads -- this is a short read
unsigned int pending = SSL_pending(ssl_);
if (pending) {
RTC_DLOG(LS_INFO) << " -- short DTLS read. flushing";
FlushInput(pending);
error = SSE_MSG_TRUNC;
return SR_ERROR;
}
}
return SR_SUCCESS;
case SSL_ERROR_WANT_READ:
RTC_DLOG(LS_VERBOSE) << " -- error want read";
return SR_BLOCK;
case SSL_ERROR_WANT_WRITE:
RTC_DLOG(LS_VERBOSE) << " -- error want write";
ssl_read_needs_write_ = true;
return SR_BLOCK;
case SSL_ERROR_ZERO_RETURN:
RTC_DLOG(LS_VERBOSE) << " -- remote side closed";
Close();
return SR_EOS;
default:
Error("SSL_read", (ssl_error ? ssl_error : -1), 0, false);
error = ssl_error_code_;
return SR_ERROR;
}
// not reached
}
void OpenSSLStreamAdapter::FlushInput(unsigned int left) {
unsigned char buf[2048];
while (left) {
// This should always succeed
const int toread = (sizeof(buf) < left) ? sizeof(buf) : left;
const int code = SSL_read(ssl_, buf, toread);
const int ssl_error = SSL_get_error(ssl_, code);
RTC_DCHECK(ssl_error == SSL_ERROR_NONE);
if (ssl_error != SSL_ERROR_NONE) {
RTC_DLOG(LS_VERBOSE) << " -- error " << code;
Error("SSL_read", (ssl_error ? ssl_error : -1), 0, false);
return;
}
RTC_DLOG(LS_VERBOSE) << " -- flushed " << code << " bytes";
left -= code;
}
}
void OpenSSLStreamAdapter::Close() {
Cleanup(0);
RTC_DCHECK(state_ == SSL_CLOSED || state_ == SSL_ERROR);
// When we're closed at SSL layer, also close the stream level which
// performs necessary clean up. Otherwise, a new incoming packet after
// this could overflow the stream buffer.
stream_->Close();
}
StreamState OpenSSLStreamAdapter::GetState() const {
switch (state_) {
case SSL_WAIT:
case SSL_CONNECTING:
return SS_OPENING;
case SSL_CONNECTED:
if (WaitingToVerifyPeerCertificate()) {
return SS_OPENING;
}
return SS_OPEN;
default:
return SS_CLOSED;
}
// not reached
}
void OpenSSLStreamAdapter::OnEvent(StreamInterface* stream,
int events,
int err) {
int events_to_signal = 0;
int signal_error = 0;
RTC_DCHECK(stream == stream_.get());
if ((events & SE_OPEN)) {
RTC_DLOG(LS_VERBOSE) << "OpenSSLStreamAdapter::OnEvent SE_OPEN";
if (state_ != SSL_WAIT) {
RTC_DCHECK(state_ == SSL_NONE);
events_to_signal |= SE_OPEN;
} else {
state_ = SSL_CONNECTING;
if (int err = BeginSSL()) {
Error("BeginSSL", err, 0, true);
return;
}
}
}
if ((events & (SE_READ | SE_WRITE))) {
RTC_DLOG(LS_VERBOSE) << "OpenSSLStreamAdapter::OnEvent"
<< ((events & SE_READ) ? " SE_READ" : "")
<< ((events & SE_WRITE) ? " SE_WRITE" : "");
if (state_ == SSL_NONE) {
events_to_signal |= events & (SE_READ | SE_WRITE);
} else if (state_ == SSL_CONNECTING) {
if (int err = ContinueSSL()) {
Error("ContinueSSL", err, 0, true);
return;
}
} else if (state_ == SSL_CONNECTED) {
if (((events & SE_READ) && ssl_write_needs_read_) ||
(events & SE_WRITE)) {
RTC_DLOG(LS_VERBOSE) << " -- onStreamWriteable";
events_to_signal |= SE_WRITE;
}
if (((events & SE_WRITE) && ssl_read_needs_write_) ||
(events & SE_READ)) {
RTC_DLOG(LS_VERBOSE) << " -- onStreamReadable";
events_to_signal |= SE_READ;
}
}
}
if ((events & SE_CLOSE)) {
RTC_DLOG(LS_VERBOSE) << "OpenSSLStreamAdapter::OnEvent(SE_CLOSE, " << err
<< ")";
Cleanup(0);
events_to_signal |= SE_CLOSE;
// SE_CLOSE is the only event that uses the final parameter to OnEvent().
RTC_DCHECK(signal_error == 0);
signal_error = err;
}
if (events_to_signal) {
// Note that the adapter presents itself as the origin of the stream events,
// since users of the adapter may not recognize the adapted object.
SignalEvent(this, events_to_signal, signal_error);
}
}
void OpenSSLStreamAdapter::PostEvent(int events, int err) {
owner_->PostTask(SafeTask(task_safety_.flag(), [this, events, err]() {
SignalEvent(this, events, err);
}));
}
void OpenSSLStreamAdapter::SetTimeout(int delay_ms) {
// We need to accept 0 delay here as well as >0 delay, because
// DTLSv1_get_timeout seems to frequently return 0 ms.
RTC_DCHECK_GE(delay_ms, 0);
RTC_DCHECK(!timeout_task_.Running());
timeout_task_ = webrtc::RepeatingTaskHandle::DelayedStart(
owner_, webrtc::TimeDelta::Millis(delay_ms),
[flag = task_safety_.flag(), this]() {
if (flag->alive()) {
RTC_DLOG(LS_INFO) << "DTLS timeout expired";
timeout_task_.Stop();
int res = DTLSv1_handle_timeout(ssl_);
if (res > 0) {
RTC_LOG(LS_INFO) << "DTLS retransmission";
} else if (res < 0) {
RTC_LOG(LS_INFO) << "DTLSv1_handle_timeout() return -1";
Error("DTLSv1_handle_timeout", res, -1, true);
return webrtc::TimeDelta::PlusInfinity();
}
ContinueSSL();
} else {
RTC_DCHECK_NOTREACHED();
}
// This callback will never run again (stopped above).
return webrtc::TimeDelta::PlusInfinity();
});
}
int OpenSSLStreamAdapter::BeginSSL() {
RTC_DCHECK(state_ == SSL_CONNECTING);
// The underlying stream has opened.
RTC_DLOG(LS_INFO) << "BeginSSL with peer.";
BIO* bio = nullptr;
// First set up the context.
RTC_DCHECK(ssl_ctx_ == nullptr);
ssl_ctx_ = SetupSSLContext();
if (!ssl_ctx_) {
return -1;
}
bio = BIO_new_stream(stream_.get());
if (!bio) {
return -1;
}
ssl_ = SSL_new(ssl_ctx_);
if (!ssl_) {
BIO_free(bio);
return -1;
}
SSL_set_app_data(ssl_, this);
SSL_set_bio(ssl_, bio, bio); // the SSL object owns the bio now.
if (ssl_mode_ == SSL_MODE_DTLS) {
#ifdef OPENSSL_IS_BORINGSSL
DTLSv1_set_initial_timeout_duration(ssl_, dtls_handshake_timeout_ms_);
#else
// Enable read-ahead for DTLS so whole packets are read from internal BIO
// before parsing. This is done internally by BoringSSL for DTLS.
SSL_set_read_ahead(ssl_, 1);
#endif
}
SSL_set_mode(ssl_, SSL_MODE_ENABLE_PARTIAL_WRITE |
SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
// Do the connect
return ContinueSSL();
}
int OpenSSLStreamAdapter::ContinueSSL() {
RTC_DLOG(LS_VERBOSE) << "ContinueSSL";
RTC_DCHECK(state_ == SSL_CONNECTING);
// Clear the DTLS timer
timeout_task_.Stop();
const int code = (role_ == SSL_CLIENT) ? SSL_connect(ssl_) : SSL_accept(ssl_);
const int ssl_error = SSL_get_error(ssl_, code);
switch (ssl_error) {
case SSL_ERROR_NONE:
RTC_DLOG(LS_VERBOSE) << " -- success";
// By this point, OpenSSL should have given us a certificate, or errored
// out if one was missing.
RTC_DCHECK(peer_cert_chain_ || !GetClientAuthEnabled());
state_ = SSL_CONNECTED;
if (!WaitingToVerifyPeerCertificate()) {
// We have everything we need to start the connection, so signal
// SE_OPEN. If we need a client certificate fingerprint and don't have
// it yet, we'll instead signal SE_OPEN in SetPeerCertificateDigest.
//
// TODO(deadbeef): Post this event asynchronously to unwind the stack.
// The caller of ContinueSSL may be the same object listening for these
// events and may not be prepared for reentrancy.
// PostEvent(SE_OPEN | SE_READ | SE_WRITE, 0);
SignalEvent(this, SE_OPEN | SE_READ | SE_WRITE, 0);
}
break;
case SSL_ERROR_WANT_READ: {
RTC_DLOG(LS_VERBOSE) << " -- error want read";
struct timeval timeout;
if (DTLSv1_get_timeout(ssl_, &timeout)) {
int delay = timeout.tv_sec * 1000 + timeout.tv_usec / 1000;
SetTimeout(delay);
}
} break;
case SSL_ERROR_WANT_WRITE:
RTC_DLOG(LS_VERBOSE) << " -- error want write";
break;
case SSL_ERROR_ZERO_RETURN:
default:
SSLHandshakeError ssl_handshake_err = SSLHandshakeError::UNKNOWN;
int err_code = ERR_peek_last_error();
if (err_code != 0 && ERR_GET_REASON(err_code) == SSL_R_NO_SHARED_CIPHER) {
ssl_handshake_err = SSLHandshakeError::INCOMPATIBLE_CIPHERSUITE;
}
RTC_DLOG(LS_VERBOSE) << " -- error " << code << ", " << err_code << ", "
<< ERR_GET_REASON(err_code);
SignalSSLHandshakeError(ssl_handshake_err);
return (ssl_error != 0) ? ssl_error : -1;
}
return 0;
}
void OpenSSLStreamAdapter::Error(absl::string_view context,
int err,
uint8_t alert,
bool signal) {
RTC_LOG(LS_WARNING) << "OpenSSLStreamAdapter::Error(" << context << ", "
<< err << ", " << static_cast<int>(alert) << ")";
state_ = SSL_ERROR;
ssl_error_code_ = err;
Cleanup(alert);
if (signal) {
SignalEvent(this, SE_CLOSE, err);
}
}
void OpenSSLStreamAdapter::Cleanup(uint8_t alert) {
RTC_DLOG(LS_INFO) << "Cleanup";
if (state_ != SSL_ERROR) {
state_ = SSL_CLOSED;
ssl_error_code_ = 0;
}
if (ssl_) {
int ret;
// SSL_send_fatal_alert is only available in BoringSSL.
#ifdef OPENSSL_IS_BORINGSSL
if (alert) {
ret = SSL_send_fatal_alert(ssl_, alert);
if (ret < 0) {
RTC_LOG(LS_WARNING) << "SSL_send_fatal_alert failed, error = "
<< SSL_get_error(ssl_, ret);
}
} else {
#endif
ret = SSL_shutdown(ssl_);
if (ret < 0) {
RTC_LOG(LS_WARNING)
<< "SSL_shutdown failed, error = " << SSL_get_error(ssl_, ret);
}
#ifdef OPENSSL_IS_BORINGSSL
}
#endif
SSL_free(ssl_);
ssl_ = nullptr;
}
if (ssl_ctx_) {
SSL_CTX_free(ssl_ctx_);
ssl_ctx_ = nullptr;
}
identity_.reset();
peer_cert_chain_.reset();
// Clear the DTLS timer
timeout_task_.Stop();
}
SSL_CTX* OpenSSLStreamAdapter::SetupSSLContext() {
#ifdef OPENSSL_IS_BORINGSSL
// If X509 objects aren't used, we can use these methods to avoid
// linking the sizable crypto/x509 code, using CRYPTO_BUFFER instead.
SSL_CTX* ctx =
SSL_CTX_new(ssl_mode_ == SSL_MODE_DTLS ? DTLS_with_buffers_method()
: TLS_with_buffers_method());
#else
SSL_CTX* ctx =
SSL_CTX_new(ssl_mode_ == SSL_MODE_DTLS ? DTLS_method() : TLS_method());
#endif
if (ctx == nullptr) {
return nullptr;
}
if (support_legacy_tls_protocols_flag_) {
// TODO(https://bugs.webrtc.org/10261): Completely remove this branch in
// M84.
SSL_CTX_set_min_proto_version(
ctx, ssl_mode_ == SSL_MODE_DTLS ? DTLS1_VERSION : TLS1_VERSION);
switch (ssl_max_version_) {
case SSL_PROTOCOL_TLS_10:
SSL_CTX_set_max_proto_version(
ctx, ssl_mode_ == SSL_MODE_DTLS ? DTLS1_VERSION : TLS1_VERSION);
break;
case SSL_PROTOCOL_TLS_11:
SSL_CTX_set_max_proto_version(
ctx, ssl_mode_ == SSL_MODE_DTLS ? DTLS1_VERSION : TLS1_1_VERSION);
break;
case SSL_PROTOCOL_TLS_12:
default:
SSL_CTX_set_max_proto_version(
ctx, ssl_mode_ == SSL_MODE_DTLS ? DTLS1_2_VERSION : TLS1_2_VERSION);
break;
}
} else {
// TODO(https://bugs.webrtc.org/10261): Make this the default in M84.
SSL_CTX_set_min_proto_version(
ctx, ssl_mode_ == SSL_MODE_DTLS ? DTLS1_2_VERSION : TLS1_2_VERSION);
SSL_CTX_set_max_proto_version(
ctx, ssl_mode_ == SSL_MODE_DTLS ? DTLS1_2_VERSION : TLS1_2_VERSION);
}
#ifdef OPENSSL_IS_BORINGSSL
// SSL_CTX_set_current_time_cb is only supported in BoringSSL.
if (g_use_time_callback_for_testing) {
SSL_CTX_set_current_time_cb(ctx, &TimeCallbackForTesting);
}
SSL_CTX_set0_buffer_pool(ctx, openssl::GetBufferPool());
#endif
if (identity_ && !identity_->ConfigureIdentity(ctx)) {
SSL_CTX_free(ctx);
return nullptr;
}
SSL_CTX_set_info_callback(ctx, OpenSSLAdapter::SSLInfoCallback);
int mode = SSL_VERIFY_PEER;
if (GetClientAuthEnabled()) {
// Require a certificate from the client.
// Note: Normally this is always true in production, but it may be disabled
// for testing purposes (e.g. SSLAdapter unit tests).
mode |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
}
// Configure a custom certificate verification callback to check the peer
// certificate digest.
#ifdef OPENSSL_IS_BORINGSSL
// Use CRYPTO_BUFFER version of the callback if building with BoringSSL.
SSL_CTX_set_custom_verify(ctx, mode, SSLVerifyCallback);
#else
// Note the second argument to SSL_CTX_set_verify is to override individual
// errors in the default verification logic, which is not what we want here.
SSL_CTX_set_verify(ctx, mode, nullptr);
SSL_CTX_set_cert_verify_callback(ctx, SSLVerifyCallback, nullptr);
#endif
// Select list of available ciphers. Note that !SHA256 and !SHA384 only
// remove HMAC-SHA256 and HMAC-SHA384 cipher suites, not GCM cipher suites
// with SHA256 or SHA384 as the handshake hash.
// This matches the list of SSLClientSocketImpl in Chromium.
SSL_CTX_set_cipher_list(
ctx,
"DEFAULT:!NULL:!aNULL:!SHA256:!SHA384:!aECDH:!AESGCM+AES256:!aPSK:!3DES");
if (!srtp_ciphers_.empty()) {
if (SSL_CTX_set_tlsext_use_srtp(ctx, srtp_ciphers_.c_str())) {
SSL_CTX_free(ctx);
return nullptr;
}
}
return ctx;
}
bool OpenSSLStreamAdapter::VerifyPeerCertificate() {
if (!HasPeerCertificateDigest() || !peer_cert_chain_ ||
!peer_cert_chain_->GetSize()) {
RTC_LOG(LS_WARNING) << "Missing digest or peer certificate.";
return false;
}
unsigned char digest[EVP_MAX_MD_SIZE];
size_t digest_length;
if (!peer_cert_chain_->Get(0).ComputeDigest(
peer_certificate_digest_algorithm_, digest, sizeof(digest),
&digest_length)) {
RTC_LOG(LS_WARNING) << "Failed to compute peer cert digest.";
return false;
}
Buffer computed_digest(digest, digest_length);
if (computed_digest != peer_certificate_digest_value_) {
RTC_LOG(LS_WARNING)
<< "Rejected peer certificate due to mismatched digest using "
<< peer_certificate_digest_algorithm_ << ". Expected "
<< rtc::hex_encode_with_delimiter(peer_certificate_digest_value_, ':')
<< " got " << rtc::hex_encode_with_delimiter(computed_digest, ':');
return false;
}
// Ignore any verification error if the digest matches, since there is no
// value in checking the validity of a self-signed cert issued by untrusted
// sources.
RTC_DLOG(LS_INFO) << "Accepted peer certificate.";
peer_certificate_verified_ = true;
return true;
}
std::unique_ptr<SSLCertChain> OpenSSLStreamAdapter::GetPeerSSLCertChain()
const {
return peer_cert_chain_ ? peer_cert_chain_->Clone() : nullptr;
}
#ifdef OPENSSL_IS_BORINGSSL
enum ssl_verify_result_t OpenSSLStreamAdapter::SSLVerifyCallback(
SSL* ssl,
uint8_t* out_alert) {
// Get our OpenSSLStreamAdapter from the context.
OpenSSLStreamAdapter* stream =
reinterpret_cast<OpenSSLStreamAdapter*>(SSL_get_app_data(ssl));
const STACK_OF(CRYPTO_BUFFER)* chain = SSL_get0_peer_certificates(ssl);
// Creates certificate chain.
std::vector<std::unique_ptr<SSLCertificate>> cert_chain;
for (CRYPTO_BUFFER* cert : chain) {
cert_chain.emplace_back(new BoringSSLCertificate(bssl::UpRef(cert)));
}
stream->peer_cert_chain_.reset(new SSLCertChain(std::move(cert_chain)));
// If the peer certificate digest isn't known yet, we'll wait to verify
// until it's known, and for now just return a success status.
if (stream->peer_certificate_digest_algorithm_.empty()) {
RTC_LOG(LS_INFO) << "Waiting to verify certificate until digest is known.";
// TODO(deadbeef): Use ssl_verify_retry?
return ssl_verify_ok;
}
if (!stream->VerifyPeerCertificate()) {
return ssl_verify_invalid;
}
return ssl_verify_ok;
}
#else // OPENSSL_IS_BORINGSSL
int OpenSSLStreamAdapter::SSLVerifyCallback(X509_STORE_CTX* store, void* arg) {
// Get our SSL structure and OpenSSLStreamAdapter from the store.
SSL* ssl = reinterpret_cast<SSL*>(
X509_STORE_CTX_get_ex_data(store, SSL_get_ex_data_X509_STORE_CTX_idx()));
OpenSSLStreamAdapter* stream =
reinterpret_cast<OpenSSLStreamAdapter*>(SSL_get_app_data(ssl));
// Record the peer's certificate.
X509* cert = X509_STORE_CTX_get0_cert(store);
stream->peer_cert_chain_.reset(
new SSLCertChain(std::make_unique<OpenSSLCertificate>(cert)));
// If the peer certificate digest isn't known yet, we'll wait to verify
// until it's known, and for now just return a success status.
if (stream->peer_certificate_digest_algorithm_.empty()) {
RTC_DLOG(LS_INFO) << "Waiting to verify certificate until digest is known.";
return 1;
}
if (!stream->VerifyPeerCertificate()) {
X509_STORE_CTX_set_error(store, X509_V_ERR_CERT_REJECTED);
return 0;
}
return 1;
}
#endif // !OPENSSL_IS_BORINGSSL
bool OpenSSLStreamAdapter::IsBoringSsl() {
#ifdef OPENSSL_IS_BORINGSSL
return true;
#else
return false;
#endif
}
#define CDEF(X) \
{ static_cast<uint16_t>(TLS1_CK_##X & 0xffff), "TLS_" #X }
struct cipher_list {
uint16_t cipher;
const char* cipher_str;
};
// TODO(torbjorng): Perhaps add more cipher suites to these lists.
static const cipher_list OK_RSA_ciphers[] = {
CDEF(ECDHE_RSA_WITH_AES_128_CBC_SHA),
CDEF(ECDHE_RSA_WITH_AES_256_CBC_SHA),
CDEF(ECDHE_RSA_WITH_AES_128_GCM_SHA256),
#ifdef TLS1_CK_ECDHE_RSA_WITH_AES_256_GCM_SHA256
CDEF(ECDHE_RSA_WITH_AES_256_GCM_SHA256),
#endif
#ifdef TLS1_CK_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
CDEF(ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256),
#endif
};
static const cipher_list OK_ECDSA_ciphers[] = {
CDEF(ECDHE_ECDSA_WITH_AES_128_CBC_SHA),
CDEF(ECDHE_ECDSA_WITH_AES_256_CBC_SHA),
CDEF(ECDHE_ECDSA_WITH_AES_128_GCM_SHA256),
#ifdef TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA256
CDEF(ECDHE_ECDSA_WITH_AES_256_GCM_SHA256),
#endif
#ifdef TLS1_CK_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
CDEF(ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256),
#endif
};
#undef CDEF
bool OpenSSLStreamAdapter::IsAcceptableCipher(int cipher, KeyType key_type) {
if (key_type == KT_RSA) {
for (const cipher_list& c : OK_RSA_ciphers) {
if (cipher == c.cipher) {
return true;
}
}
}
if (key_type == KT_ECDSA) {
for (const cipher_list& c : OK_ECDSA_ciphers) {
if (cipher == c.cipher) {
return true;
}
}
}
return false;
}
bool OpenSSLStreamAdapter::IsAcceptableCipher(absl::string_view cipher,
KeyType key_type) {
if (key_type == KT_RSA) {
for (const cipher_list& c : OK_RSA_ciphers) {
if (cipher == c.cipher_str) {
return true;
}
}
}
if (key_type == KT_ECDSA) {
for (const cipher_list& c : OK_ECDSA_ciphers) {
if (cipher == c.cipher_str) {
return true;
}
}
}
return false;
}
void OpenSSLStreamAdapter::EnableTimeCallbackForTesting() {
#ifdef OPENSSL_IS_BORINGSSL
g_use_time_callback_for_testing = true;
#endif
}
} // namespace rtc