tdlight/tdnet/td/net/SslStream.cpp

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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/net/SslStream.h"
#include "td/utils/logging.h"
#include "td/utils/misc.h"
#include "td/utils/port/wstring_convert.h"
#include "td/utils/StackAllocator.h"
#include "td/utils/Status.h"
#include "td/utils/StringBuilder.h"
#include "td/utils/Time.h"
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/ssl.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <cstring>
#include <map>
#include <mutex>
#if TD_PORT_WINDOWS
#include <wincrypt.h>
#endif
namespace td {
namespace detail {
namespace {
#if OPENSSL_VERSION_NUMBER < 0x10100000L
void *BIO_get_data(BIO *b) {
return b->ptr;
}
void BIO_set_data(BIO *b, void *ptr) {
b->ptr = ptr;
}
void BIO_set_init(BIO *b, int init) {
b->init = init;
}
int BIO_get_new_index() {
return 0;
}
BIO_METHOD *BIO_meth_new(int type, const char *name) {
auto res = new BIO_METHOD();
std::memset(res, 0, sizeof(*res));
return res;
}
int BIO_meth_set_write(BIO_METHOD *biom, int (*bwrite)(BIO *, const char *, int)) {
biom->bwrite = bwrite;
return 1;
}
int BIO_meth_set_read(BIO_METHOD *biom, int (*bread)(BIO *, char *, int)) {
biom->bread = bread;
return 1;
}
int BIO_meth_set_ctrl(BIO_METHOD *biom, long (*ctrl)(BIO *, int, long, void *)) {
biom->ctrl = ctrl;
return 1;
}
int BIO_meth_set_create(BIO_METHOD *biom, int (*create)(BIO *)) {
biom->create = create;
return 1;
}
int BIO_meth_set_destroy(BIO_METHOD *biom, int (*destroy)(BIO *)) {
biom->destroy = destroy;
return 1;
}
#endif
int strm_create(BIO *b) {
BIO_set_init(b, 1);
return 1;
}
int strm_destroy(BIO *b) {
return 1;
}
int strm_read(BIO *b, char *buf, int len);
int strm_write(BIO *b, const char *buf, int len);
long strm_ctrl(BIO *b, int cmd, long num, void *ptr) {
switch (cmd) {
case BIO_CTRL_FLUSH:
return 1;
case BIO_CTRL_PUSH:
return 0;
case BIO_CTRL_POP:
return 0;
default:
LOG(FATAL) << b << " " << cmd << " " << num << " " << ptr;
}
return 1;
}
BIO_METHOD *BIO_s_sslstream() {
static BIO_METHOD *result = [] {
BIO_METHOD *res = BIO_meth_new(BIO_get_new_index(), "td::SslStream helper bio");
BIO_meth_set_write(res, strm_write);
BIO_meth_set_read(res, strm_read);
BIO_meth_set_create(res, strm_create);
BIO_meth_set_destroy(res, strm_destroy);
BIO_meth_set_ctrl(res, strm_ctrl);
return res;
}();
return result;
}
int verify_callback(int preverify_ok, X509_STORE_CTX *ctx) {
if (!preverify_ok) {
char buf[256];
X509_NAME_oneline(X509_get_subject_name(X509_STORE_CTX_get_current_cert(ctx)), buf, 256);
int err = X509_STORE_CTX_get_error(ctx);
auto warning = PSTRING() << "verify error:num=" << err << ":" << X509_verify_cert_error_string(err)
<< ":depth=" << X509_STORE_CTX_get_error_depth(ctx) << ":" << buf;
double now = Time::now();
static std::mutex warning_mutex;
{
std::lock_guard<std::mutex> lock(warning_mutex);
static std::map<std::string, double> next_warning_time;
double &next = next_warning_time[warning];
if (next <= now) {
next = now + 300; // one warning per 5 minutes
LOG(WARNING) << warning;
}
}
}
return preverify_ok;
}
Status create_openssl_error(int code, Slice message) {
const int max_result_size = 1 << 12;
auto result = StackAllocator::alloc(max_result_size);
StringBuilder sb(result.as_slice());
sb << message;
while (unsigned long error_code = ERR_get_error()) {
char error_buf[1024];
ERR_error_string_n(error_code, error_buf, sizeof(error_buf));
Slice error(error_buf, std::strlen(error_buf));
sb << "{" << error << "}";
}
LOG_IF(ERROR, sb.is_error()) << "OpenSSL error buffer overflow";
LOG(DEBUG) << sb.as_cslice();
return Status::Error(code, sb.as_cslice());
}
void openssl_clear_errors(Slice from) {
if (ERR_peek_error() != 0) {
LOG(ERROR) << from << ": " << create_openssl_error(0, "Unprocessed OPENSSL_ERROR");
}
#if TD_PORT_WINDOWS // TODO move to utils
WSASetLastError(0);
#else
errno = 0;
#endif
}
void do_ssl_shutdown(SSL *ssl_handle) {
if (!SSL_is_init_finished(ssl_handle)) {
return;
}
openssl_clear_errors("Before SSL_shutdown");
SSL_set_quiet_shutdown(ssl_handle, 1);
SSL_shutdown(ssl_handle);
openssl_clear_errors("After SSL_shutdown");
}
} // namespace
class SslStreamImpl {
public:
using VerifyPeer = SslStream::VerifyPeer;
~SslStreamImpl() {
if (!ssl_handle_) {
CHECK(!ssl_ctx_ && !bio_);
return;
}
CHECK(ssl_handle_ && ssl_ctx_ && bio_);
do_ssl_shutdown(ssl_handle_);
SSL_free(ssl_handle_);
ssl_handle_ = nullptr;
SSL_CTX_free(ssl_ctx_);
ssl_ctx_ = nullptr;
}
Status init(CSlice host, CSlice cert_file, VerifyPeer verify_peer) {
static bool init_openssl = [] {
#if OPENSSL_VERSION_NUMBER >= 0x10100000L
return OPENSSL_init_ssl(0, nullptr) != 0;
#else
OpenSSL_add_all_algorithms();
SSL_load_error_strings();
return OpenSSL_add_ssl_algorithms() != 0;
#endif
}();
CHECK(init_openssl);
openssl_clear_errors("Before SslFd::init");
auto ssl_method =
#if OPENSSL_VERSION_NUMBER >= 0x10100000L
TLS_client_method();
#else
SSLv23_client_method();
#endif
if (ssl_method == nullptr) {
return create_openssl_error(-6, "Failed to create an SSL client method");
}
auto ssl_ctx = SSL_CTX_new(ssl_method);
if (ssl_ctx == nullptr) {
return create_openssl_error(-7, "Failed to create an SSL context");
}
auto ssl_ctx_guard = ScopeExit() + [&]() { SSL_CTX_free(ssl_ctx); };
long options = 0;
#ifdef SSL_OP_NO_SSLv2
options |= SSL_OP_NO_SSLv2;
#endif
#ifdef SSL_OP_NO_SSLv3
options |= SSL_OP_NO_SSLv3;
#endif
SSL_CTX_set_options(ssl_ctx, options);
SSL_CTX_set_mode(ssl_ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER | SSL_MODE_ENABLE_PARTIAL_WRITE);
if (cert_file.empty()) {
#if TD_PORT_WINDOWS
// TODO thread-local SSL_CTX cache
LOG(DEBUG) << "Begin to load system store";
auto flags = CERT_STORE_OPEN_EXISTING_FLAG | CERT_STORE_READONLY_FLAG | CERT_SYSTEM_STORE_CURRENT_USER;
HCERTSTORE system_store =
CertOpenStore(CERT_STORE_PROV_SYSTEM_W, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, HCRYPTPROV_LEGACY(), flags,
static_cast<const void *>(to_wstring("ROOT").ok().c_str()));
if (system_store) {
X509_STORE *store = X509_STORE_new();
for (PCCERT_CONTEXT cert_context = CertEnumCertificatesInStore(system_store, nullptr); cert_context != nullptr;
cert_context = CertEnumCertificatesInStore(system_store, cert_context)) {
const unsigned char *in = cert_context->pbCertEncoded;
X509 *x509 = d2i_X509(nullptr, &in, static_cast<long>(cert_context->cbCertEncoded));
if (x509 != nullptr) {
if (X509_STORE_add_cert(store, x509) != 1) {
LOG(ERROR) << "Failed to add certificate";
}
X509_free(x509);
} else {
LOG(ERROR) << "Failed to load X509 certificate";
}
}
CertCloseStore(system_store, 0);
SSL_CTX_set_cert_store(ssl_ctx, store);
LOG(DEBUG) << "End to load system store";
} else {
LOG(ERROR) << "Failed to open system certificate store";
}
#else
if (SSL_CTX_set_default_verify_paths(ssl_ctx) == 0) {
auto error = create_openssl_error(-8, "Failed to load default verify paths");
if (verify_peer == VerifyPeer::On) {
return error;
} else {
LOG(ERROR) << error;
}
}
#endif
} else {
if (SSL_CTX_load_verify_locations(ssl_ctx, cert_file.c_str(), nullptr) == 0) {
return create_openssl_error(-8, "Failed to set custom cert file");
}
}
if (verify_peer == VerifyPeer::On) {
SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, verify_callback);
if (VERIFY_DEPTH != -1) {
SSL_CTX_set_verify_depth(ssl_ctx, VERIFY_DEPTH);
}
} else {
SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_NONE, nullptr);
}
// TODO(now): cipher list
string cipher_list;
if (SSL_CTX_set_cipher_list(ssl_ctx, cipher_list.empty() ? "DEFAULT" : cipher_list.c_str()) == 0) {
return create_openssl_error(-9, PSLICE() << "Failed to set cipher list \"" << cipher_list << '"');
}
auto ssl_handle = SSL_new(ssl_ctx);
if (ssl_handle == nullptr) {
return create_openssl_error(-13, "Failed to create an SSL handle");
}
auto ssl_handle_guard = ScopeExit() + [&]() {
do_ssl_shutdown(ssl_handle);
SSL_free(ssl_handle);
};
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
X509_VERIFY_PARAM *param = SSL_get0_param(ssl_handle);
/* Enable automatic hostname checks */
// TODO: X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
X509_VERIFY_PARAM_set_hostflags(param, 0);
X509_VERIFY_PARAM_set1_host(param, host.c_str(), 0);
#else
#warning DANGEROUS! HTTPS HOST WILL NOT BE CHECKED. INSTALL OPENSSL >= 1.0.2 OR IMPLEMENT HTTPS HOST CHECK MANUALLY
#endif
auto *bio = BIO_new(BIO_s_sslstream());
BIO_set_data(bio, static_cast<void *>(this));
SSL_set_bio(ssl_handle, bio, bio);
#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
auto host_str = host.str();
SSL_set_tlsext_host_name(ssl_handle, MutableCSlice(host_str).begin());
#endif
SSL_set_connect_state(ssl_handle);
ssl_ctx_guard.dismiss();
ssl_handle_guard.dismiss();
ssl_handle_ = ssl_handle;
ssl_ctx_ = ssl_ctx;
bio_ = bio;
return Status::OK();
}
ByteFlowInterface &read_byte_flow() {
return read_flow_;
}
ByteFlowInterface &write_byte_flow() {
return write_flow_;
}
size_t flow_read(MutableSlice slice) {
return read_flow_.read(slice);
}
size_t flow_write(Slice slice) {
return write_flow_.write(slice);
}
private:
static constexpr int VERIFY_DEPTH = 10;
SSL *ssl_handle_ = nullptr;
SSL_CTX *ssl_ctx_ = nullptr;
BIO *bio_ = nullptr;
friend class SslReadByteFlow;
friend class SslWriteByteFlow;
Result<size_t> write(Slice slice) {
openssl_clear_errors("Before SslFd::write");
auto size = SSL_write(ssl_handle_, slice.data(), static_cast<int>(slice.size()));
if (size <= 0) {
return process_ssl_error(size);
}
return size;
}
Result<size_t> read(MutableSlice slice) {
openssl_clear_errors("Before SslFd::read");
auto size = SSL_read(ssl_handle_, slice.data(), static_cast<int>(slice.size()));
if (size <= 0) {
return process_ssl_error(size);
}
return size;
}
class SslReadByteFlow : public ByteFlowBase {
public:
explicit SslReadByteFlow(SslStreamImpl *stream) : stream_(stream) {
}
void loop() override {
bool was_append = false;
while (true) {
auto to_read = output_.prepare_append();
auto r_size = stream_->read(to_read);
if (r_size.is_error()) {
return finish(r_size.move_as_error());
}
auto size = r_size.move_as_ok();
if (size == 0) {
break;
}
output_.confirm_append(size);
was_append = true;
}
if (was_append) {
on_output_updated();
}
}
size_t read(MutableSlice data) {
return input_->advance(min(data.size(), input_->size()), data);
}
private:
SslStreamImpl *stream_;
};
class SslWriteByteFlow : public ByteFlowBase {
public:
explicit SslWriteByteFlow(SslStreamImpl *stream) : stream_(stream) {
}
void loop() override {
while (!input_->empty()) {
auto to_write = input_->prepare_read();
auto r_size = stream_->write(to_write);
if (r_size.is_error()) {
return finish(r_size.move_as_error());
}
auto size = r_size.move_as_ok();
if (size == 0) {
break;
}
input_->confirm_read(size);
}
if (output_updated_) {
output_updated_ = false;
on_output_updated();
}
}
size_t write(Slice data) {
output_.append(data);
output_updated_ = true;
return data.size();
}
private:
SslStreamImpl *stream_;
bool output_updated_{false};
};
SslReadByteFlow read_flow_{this};
SslWriteByteFlow write_flow_{this};
Result<size_t> process_ssl_error(int ret) {
auto os_error = OS_ERROR("SSL_ERROR_SYSCALL");
int error = SSL_get_error(ssl_handle_, ret);
switch (error) {
case SSL_ERROR_NONE:
LOG(ERROR) << "SSL_get_error returned no error";
return 0;
case SSL_ERROR_ZERO_RETURN:
LOG(DEBUG) << "SSL_ERROR_ZERO_RETURN";
return 0;
case SSL_ERROR_WANT_READ:
LOG(DEBUG) << "SSL_ERROR_WANT_READ";
return 0;
case SSL_ERROR_WANT_WRITE:
LOG(DEBUG) << "SSL_ERROR_WANT_WRITE";
return 0;
case SSL_ERROR_WANT_CONNECT:
case SSL_ERROR_WANT_ACCEPT:
case SSL_ERROR_WANT_X509_LOOKUP:
LOG(DEBUG) << "SSL_ERROR: CONNECT ACCEPT LOOKUP";
return 0;
case SSL_ERROR_SYSCALL:
LOG(DEBUG) << "SSL_ERROR_SYSCALL";
if (ERR_peek_error() == 0) {
if (os_error.code() != 0) {
return std::move(os_error);
} else {
return 0;
}
}
/* fall through */
default:
LOG(DEBUG) << "SSL_ERROR Default";
return create_openssl_error(1, "SSL error ");
}
}
};
namespace {
int strm_read(BIO *b, char *buf, int len) {
auto *stream = static_cast<SslStreamImpl *>(BIO_get_data(b));
CHECK(stream != nullptr);
BIO_clear_retry_flags(b);
int res = narrow_cast<int>(stream->flow_read(MutableSlice(buf, len)));
if (res == 0) {
BIO_set_retry_read(b);
return -1;
}
return res;
}
int strm_write(BIO *b, const char *buf, int len) {
auto *stream = static_cast<SslStreamImpl *>(BIO_get_data(b));
CHECK(stream != nullptr);
BIO_clear_retry_flags(b);
return narrow_cast<int>(stream->flow_write(Slice(buf, len)));
}
} // namespace
} // namespace detail
SslStream::SslStream() = default;
SslStream::SslStream(SslStream &&) = default;
SslStream &SslStream::operator=(SslStream &&) = default;
SslStream::~SslStream() = default;
Result<SslStream> SslStream::create(CSlice host, CSlice cert_file, VerifyPeer verify_peer) {
auto impl = std::make_unique<detail::SslStreamImpl>();
TRY_STATUS(impl->init(host, cert_file, verify_peer));
return SslStream(std::move(impl));
}
SslStream::SslStream(std::unique_ptr<detail::SslStreamImpl> impl) : impl_(std::move(impl)) {
}
ByteFlowInterface &SslStream::read_byte_flow() {
return impl_->read_byte_flow();
}
ByteFlowInterface &SslStream::write_byte_flow() {
return impl_->write_byte_flow();
}
size_t SslStream::flow_read(MutableSlice slice) {
return impl_->flow_read(slice);
}
size_t SslStream::flow_write(Slice slice) {
return impl_->flow_write(slice);
}
} // namespace td