tls/tls_connection.cpp - platform/packages/modules/adb - Git at Google

 /*
  * Copyright (C) 2019 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "adb/tls/tls_connection.h"

 #include <limits.h>

 #include <algorithm>
 #include <vector>

 #include <android-base/logging.h>
 #include <android-base/strings.h>
 #include <openssl/err.h>
 #include <openssl/ssl.h>

 using android::base::borrowed_fd;

 namespace adb {
 namespace tls {

 namespace {

 static constexpr char kExportedKeyLabel[] = "adb-label";

 class TlsConnectionImpl : public TlsConnection {
   public:
     explicit TlsConnectionImpl(Role role, std::string_view cert, std::string_view priv_key,
                                borrowed_fd fd);
     ~TlsConnectionImpl() override;

     bool AddTrustedCertificate(std::string_view cert) override;
     void SetCertVerifyCallback(CertVerifyCb cb) override;
     void SetCertificateCallback(SetCertCb cb) override;
     void SetClientCAList(STACK_OF(X509_NAME) * ca_list) override;
     std::vector<uint8_t> ExportKeyingMaterial(size_t length) override;
     void EnableClientPostHandshakeCheck(bool enable) override;
     TlsError DoHandshake() override;
     std::vector<uint8_t> ReadFully(size_t size) override;
     bool ReadFully(void* buf, size_t size) override;
     bool WriteFully(std::string_view data) override;

     static bssl::UniquePtr<EVP_PKEY> EvpPkeyFromPEM(std::string_view pem);
     static bssl::UniquePtr<CRYPTO_BUFFER> BufferFromPEM(std::string_view pem);

   private:
     static int SSLSetCertVerifyCb(X509_STORE_CTX* ctx, void* opaque);
     static int SSLSetCertCb(SSL* ssl, void* opaque);

     static bssl::UniquePtr<X509> X509FromBuffer(bssl::UniquePtr<CRYPTO_BUFFER> buffer);
     static const char* SSLErrorString();
     void Invalidate();
     TlsError GetFailureReason(int err);
     const char* RoleToString() { return role_ == Role::Server ? kServerRoleStr : kClientRoleStr; }

     Role role_;
     bssl::UniquePtr<EVP_PKEY> priv_key_;
     bssl::UniquePtr<CRYPTO_BUFFER> cert_;

     bssl::UniquePtr<STACK_OF(X509_NAME)> ca_list_;
     bssl::UniquePtr<SSL_CTX> ssl_ctx_;
     bssl::UniquePtr<SSL> ssl_;
     std::vector<bssl::UniquePtr<X509>> known_certificates_;
     bool client_verify_post_handshake_ = false;

     CertVerifyCb cert_verify_cb_;
     SetCertCb set_cert_cb_;
     borrowed_fd fd_;
     static constexpr char kClientRoleStr[] = "[client]: ";
     static constexpr char kServerRoleStr[] = "[server]: ";
 };  // TlsConnectionImpl

 TlsConnectionImpl::TlsConnectionImpl(Role role, std::string_view cert, std::string_view priv_key,
                                      borrowed_fd fd)
     : role_(role), fd_(fd) {
     CHECK(!cert.empty() && !priv_key.empty());
     LOG(INFO) << RoleToString() << "Initializing adbwifi TlsConnection";
     cert_ = BufferFromPEM(cert);
     CHECK(cert_);
     priv_key_ = EvpPkeyFromPEM(priv_key);
     CHECK(priv_key_);
 }

 TlsConnectionImpl::~TlsConnectionImpl() {
     // shutdown the SSL connection
     if (ssl_ != nullptr) {
         SSL_shutdown(ssl_.get());
     }
 }

 // static
 const char* TlsConnectionImpl::SSLErrorString() {
     auto sslerr = ERR_peek_last_error();
     return ERR_reason_error_string(sslerr);
 }

 // static
 bssl::UniquePtr<EVP_PKEY> TlsConnectionImpl::EvpPkeyFromPEM(std::string_view pem) {
     bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(pem.data(), pem.size()));
     return bssl::UniquePtr<EVP_PKEY>(PEM_read_bio_PrivateKey(bio.get(), nullptr, nullptr, nullptr));
 }

 // static
 bssl::UniquePtr<CRYPTO_BUFFER> TlsConnectionImpl::BufferFromPEM(std::string_view pem) {
     bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(pem.data(), pem.size()));
     char* name = nullptr;
     char* header = nullptr;
     uint8_t* data = nullptr;
     long data_len = 0;

     if (!PEM_read_bio(bio.get(), &name, &header, &data, &data_len)) {
         LOG(ERROR) << "Failed to read certificate";
         return nullptr;
     }
     OPENSSL_free(name);
     OPENSSL_free(header);

     auto ret = bssl::UniquePtr<CRYPTO_BUFFER>(CRYPTO_BUFFER_new(data, data_len, nullptr));
     OPENSSL_free(data);
     return ret;
 }

 // static
 bssl::UniquePtr<X509> TlsConnectionImpl::X509FromBuffer(bssl::UniquePtr<CRYPTO_BUFFER> buffer) {
     if (!buffer) {
         return nullptr;
     }
     return bssl::UniquePtr<X509>(X509_parse_from_buffer(buffer.get()));
 }

 // static
 int TlsConnectionImpl::SSLSetCertVerifyCb(X509_STORE_CTX* ctx, void* opaque) {
     auto* p = reinterpret_cast<TlsConnectionImpl*>(opaque);
     return p->cert_verify_cb_(ctx);
 }

 // static
 int TlsConnectionImpl::SSLSetCertCb(SSL* ssl, void* opaque) {
     auto* p = reinterpret_cast<TlsConnectionImpl*>(opaque);
     return p->set_cert_cb_(ssl);
 }

 bool TlsConnectionImpl::AddTrustedCertificate(std::string_view cert) {
     // Create X509 buffer from the certificate string
     auto buf = X509FromBuffer(BufferFromPEM(cert));
     if (buf == nullptr) {
         LOG(ERROR) << RoleToString() << "Failed to create a X509 buffer for the certificate.";
         return false;
     }
     known_certificates_.push_back(std::move(buf));
     return true;
 }

 void TlsConnectionImpl::SetCertVerifyCallback(CertVerifyCb cb) {
     cert_verify_cb_ = cb;
 }

 void TlsConnectionImpl::SetCertificateCallback(SetCertCb cb) {
     set_cert_cb_ = cb;
 }

 void TlsConnectionImpl::SetClientCAList(STACK_OF(X509_NAME) * ca_list) {
     CHECK(role_ == Role::Server);
     ca_list_.reset(ca_list != nullptr ? SSL_dup_CA_list(ca_list) : nullptr);
 }

 std::vector<uint8_t> TlsConnectionImpl::ExportKeyingMaterial(size_t length) {
     if (ssl_.get() == nullptr) {
         return {};
     }

     std::vector<uint8_t> out(length);
     if (SSL_export_keying_material(ssl_.get(), out.data(), out.size(), kExportedKeyLabel,
                                    sizeof(kExportedKeyLabel), nullptr, 0, false) == 0) {
         return {};
     }
     return out;
 }

 void TlsConnectionImpl::EnableClientPostHandshakeCheck(bool enable) {
     client_verify_post_handshake_ = enable;
 }

 TlsConnection::TlsError TlsConnectionImpl::GetFailureReason(int err) {
     switch (ERR_GET_REASON(err)) {
         case SSL_R_SSLV3_ALERT_BAD_CERTIFICATE:
         case SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE:
         case SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED:
         case SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED:
         case SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN:
         case SSL_R_TLSV1_ALERT_ACCESS_DENIED:
         case SSL_R_TLSV1_ALERT_UNKNOWN_CA:
         case SSL_R_TLSV1_CERTIFICATE_REQUIRED:
             return TlsError::PeerRejectedCertificate;
         case SSL_R_CERTIFICATE_VERIFY_FAILED:
             return TlsError::CertificateRejected;
         default:
             return TlsError::UnknownFailure;
     }
 }

 TlsConnection::TlsError TlsConnectionImpl::DoHandshake() {
     LOG(INFO) << RoleToString() << "Starting adbwifi tls handshake";
     ssl_ctx_.reset(SSL_CTX_new(TLS_method()));
     // TODO: Remove set_max_proto_version() once external/boringssl is updated
     // past
     // https://boringssl.googlesource.com/boringssl/+/58d56f4c59969a23e5f52014e2651c76fea2f877
     if (ssl_ctx_.get() == nullptr ||
         !SSL_CTX_set_min_proto_version(ssl_ctx_.get(), TLS1_3_VERSION) ||
         !SSL_CTX_set_max_proto_version(ssl_ctx_.get(), TLS1_3_VERSION)) {
         LOG(ERROR) << RoleToString() << "Failed to create SSL context";
         return TlsError::UnknownFailure;
     }

     // Register user-supplied known certificates
     for (auto const& cert : known_certificates_) {
         if (X509_STORE_add_cert(SSL_CTX_get_cert_store(ssl_ctx_.get()), cert.get()) == 0) {
             LOG(ERROR) << RoleToString() << "Unable to add certificates into the X509_STORE";
             return TlsError::UnknownFailure;
         }
     }

     // Custom certificate verification
     if (cert_verify_cb_) {
         SSL_CTX_set_cert_verify_callback(ssl_ctx_.get(), SSLSetCertVerifyCb, this);
     }

     // set select certificate callback, if any.
     if (set_cert_cb_) {
         SSL_CTX_set_cert_cb(ssl_ctx_.get(), SSLSetCertCb, this);
     }

     // Server-allowed client CA list
     if (ca_list_ != nullptr) {
         bssl::UniquePtr<STACK_OF(X509_NAME)> names(SSL_dup_CA_list(ca_list_.get()));
         SSL_CTX_set_client_CA_list(ssl_ctx_.get(), names.release());
     }

     // Register our certificate and private key.
     std::vector<CRYPTO_BUFFER*> cert_chain = {
             cert_.get(),
     };
     if (!SSL_CTX_set_chain_and_key(ssl_ctx_.get(), cert_chain.data(), cert_chain.size(),
                                    priv_key_.get(), nullptr)) {
         LOG(ERROR) << RoleToString()
                    << "Unable to register the certificate chain file and private key ["
                    << SSLErrorString() << "]";
         Invalidate();
         return TlsError::UnknownFailure;
     }

     SSL_CTX_set_verify(ssl_ctx_.get(), SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);

     // Okay! Let's try to do the handshake!
     ssl_.reset(SSL_new(ssl_ctx_.get()));
     if (!SSL_set_fd(ssl_.get(), fd_.get())) {
         LOG(ERROR) << RoleToString() << "SSL_set_fd failed. [" << SSLErrorString() << "]";
         return TlsError::UnknownFailure;
     }

     switch (role_) {
         case Role::Server:
             SSL_set_accept_state(ssl_.get());
             break;
         case Role::Client:
             SSL_set_connect_state(ssl_.get());
             break;
     }
     if (SSL_do_handshake(ssl_.get()) != 1) {
         LOG(ERROR) << RoleToString() << "Handshake failed in SSL_accept/SSL_connect ["
                    << SSLErrorString() << "]";
         auto sslerr = ERR_get_error();
         Invalidate();
         return GetFailureReason(sslerr);
     }

     if (client_verify_post_handshake_ && role_ == Role::Client) {
         uint8_t check;
         // Try to peek one byte for any failures. This assumes on success that
         // the server actually sends something.
         if (SSL_peek(ssl_.get(), &check, 1) <= 0) {
             LOG(ERROR) << RoleToString() << "Post-handshake SSL_peek failed [" << SSLErrorString()
                        << "]";
             auto sslerr = ERR_get_error();
             Invalidate();
             return GetFailureReason(sslerr);
         }
     }

     LOG(INFO) << RoleToString() << "Handshake succeeded.";
     return TlsError::Success;
 }

 void TlsConnectionImpl::Invalidate() {
     ssl_.reset();
     ssl_ctx_.reset();
 }

 std::vector<uint8_t> TlsConnectionImpl::ReadFully(size_t size) {
     std::vector<uint8_t> buf(size);
     if (!ReadFully(buf.data(), buf.size())) {
         return {};
     }

     return buf;
 }

 bool TlsConnectionImpl::ReadFully(void* buf, size_t size) {
     CHECK_GT(size, 0U);
     if (!ssl_) {
         LOG(ERROR) << RoleToString() << "Tried to read on a null SSL connection";
         return false;
     }

     size_t offset = 0;
     uint8_t* p8 = reinterpret_cast<uint8_t*>(buf);
     while (size > 0) {
         int bytes_read =
                 SSL_read(ssl_.get(), p8 + offset, std::min(static_cast<size_t>(INT_MAX), size));
         if (bytes_read <= 0) {
             LOG(ERROR) << RoleToString() << "SSL_read failed [" << SSLErrorString() << "]";
             return false;
         }
         size -= bytes_read;
         offset += bytes_read;
     }
     return true;
 }

 bool TlsConnectionImpl::WriteFully(std::string_view data) {
     CHECK(!data.empty());
     if (!ssl_) {
         LOG(ERROR) << RoleToString() << "Tried to read on a null SSL connection";
         return false;
     }

     while (!data.empty()) {
         int bytes_out = SSL_write(ssl_.get(), data.data(),
                                   std::min(static_cast<size_t>(INT_MAX), data.size()));
         if (bytes_out <= 0) {
             LOG(ERROR) << RoleToString() << "SSL_write failed [" << SSLErrorString() << "]";
             return false;
         }
         data = data.substr(bytes_out);
     }
     return true;
 }
 }  // namespace

 // static
 std::unique_ptr<TlsConnection> TlsConnection::Create(TlsConnection::Role role,
                                                      std::string_view cert,
                                                      std::string_view priv_key, borrowed_fd fd) {
     CHECK(!cert.empty());
     CHECK(!priv_key.empty());

     return std::make_unique<TlsConnectionImpl>(role, cert, priv_key, fd);
 }

 // static
 bool TlsConnection::SetCertAndKey(SSL* ssl, std::string_view cert, std::string_view priv_key) {
     CHECK(ssl);
     // Note: declaring these in local scope is okay because
     // SSL_set_chain_and_key will increase the refcount (bssl::UpRef).
     auto x509_cert = TlsConnectionImpl::BufferFromPEM(cert);
     auto evp_pkey = TlsConnectionImpl::EvpPkeyFromPEM(priv_key);
     if (x509_cert == nullptr || evp_pkey == nullptr) {
         return false;
     }

     std::vector<CRYPTO_BUFFER*> cert_chain = {
             x509_cert.get(),
     };
     if (!SSL_set_chain_and_key(ssl, cert_chain.data(), cert_chain.size(), evp_pkey.get(),
                                nullptr)) {
         LOG(ERROR) << "SSL_set_chain_and_key failed";
         return false;
     }

     return true;
 }

 }  // namespace tls
 }  // namespace adb
	/*
	* Copyright (C) 2019 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except
	* in compliance with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "adb/tls/tls_connection.h"

	#include <limits.h>

	#include <algorithm>
	#include <vector>

	#include <android-base/logging.h>
	#include <android-base/strings.h>
	#include <openssl/err.h>
	#include <openssl/ssl.h>

	using android::base::borrowed_fd;

	namespace adb {
	namespace tls {

	namespace {

	static constexpr char kExportedKeyLabel[] = "adb-label";

	class TlsConnectionImpl : public TlsConnection {
	public:
	explicit TlsConnectionImpl(Role role, std::string_view cert, std::string_view priv_key,
	borrowed_fd fd);
	~TlsConnectionImpl() override;

	bool AddTrustedCertificate(std::string_view cert) override;
	void SetCertVerifyCallback(CertVerifyCb cb) override;
	void SetCertificateCallback(SetCertCb cb) override;
	void SetClientCAList(STACK_OF(X509_NAME) * ca_list) override;
	std::vector<uint8_t> ExportKeyingMaterial(size_t length) override;
	void EnableClientPostHandshakeCheck(bool enable) override;
	TlsError DoHandshake() override;
	std::vector<uint8_t> ReadFully(size_t size) override;
	bool ReadFully(void* buf, size_t size) override;
	bool WriteFully(std::string_view data) override;

	static bssl::UniquePtr<EVP_PKEY> EvpPkeyFromPEM(std::string_view pem);
	static bssl::UniquePtr<CRYPTO_BUFFER> BufferFromPEM(std::string_view pem);

	private:
	static int SSLSetCertVerifyCb(X509_STORE_CTX* ctx, void* opaque);
	static int SSLSetCertCb(SSL* ssl, void* opaque);

	static bssl::UniquePtr<X509> X509FromBuffer(bssl::UniquePtr<CRYPTO_BUFFER> buffer);
	static const char* SSLErrorString();
	void Invalidate();
	TlsError GetFailureReason(int err);
	const char* RoleToString() { return role_ == Role::Server ? kServerRoleStr : kClientRoleStr; }

	Role role_;
	bssl::UniquePtr<EVP_PKEY> priv_key_;
	bssl::UniquePtr<CRYPTO_BUFFER> cert_;

	bssl::UniquePtr<STACK_OF(X509_NAME)> ca_list_;
	bssl::UniquePtr<SSL_CTX> ssl_ctx_;
	bssl::UniquePtr<SSL> ssl_;
	std::vector<bssl::UniquePtr<X509>> known_certificates_;
	bool client_verify_post_handshake_ = false;

	CertVerifyCb cert_verify_cb_;
	SetCertCb set_cert_cb_;
	borrowed_fd fd_;
	static constexpr char kClientRoleStr[] = "[client]: ";
	static constexpr char kServerRoleStr[] = "[server]: ";
	}; // TlsConnectionImpl

	TlsConnectionImpl::TlsConnectionImpl(Role role, std::string_view cert, std::string_view priv_key,
	borrowed_fd fd)
	: role_(role), fd_(fd) {
	CHECK(!cert.empty() && !priv_key.empty());
	LOG(INFO) << RoleToString() << "Initializing adbwifi TlsConnection";
	cert_ = BufferFromPEM(cert);
	CHECK(cert_);
	priv_key_ = EvpPkeyFromPEM(priv_key);
	CHECK(priv_key_);
	}

	TlsConnectionImpl::~TlsConnectionImpl() {
	// shutdown the SSL connection
	if (ssl_ != nullptr) {
	SSL_shutdown(ssl_.get());
	}
	}

	// static
	const char* TlsConnectionImpl::SSLErrorString() {
	auto sslerr = ERR_peek_last_error();
	return ERR_reason_error_string(sslerr);
	}

	// static
	bssl::UniquePtr<EVP_PKEY> TlsConnectionImpl::EvpPkeyFromPEM(std::string_view pem) {
	bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(pem.data(), pem.size()));
	return bssl::UniquePtr<EVP_PKEY>(PEM_read_bio_PrivateKey(bio.get(), nullptr, nullptr, nullptr));
	}

	// static
	bssl::UniquePtr<CRYPTO_BUFFER> TlsConnectionImpl::BufferFromPEM(std::string_view pem) {
	bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(pem.data(), pem.size()));
	char* name = nullptr;
	char* header = nullptr;
	uint8_t* data = nullptr;
	long data_len = 0;

	if (!PEM_read_bio(bio.get(), &name, &header, &data, &data_len)) {
	LOG(ERROR) << "Failed to read certificate";
	return nullptr;
	}
	OPENSSL_free(name);
	OPENSSL_free(header);

	auto ret = bssl::UniquePtr<CRYPTO_BUFFER>(CRYPTO_BUFFER_new(data, data_len, nullptr));
	OPENSSL_free(data);
	return ret;
	}

	// static
	bssl::UniquePtr<X509> TlsConnectionImpl::X509FromBuffer(bssl::UniquePtr<CRYPTO_BUFFER> buffer) {
	if (!buffer) {
	return nullptr;
	}
	return bssl::UniquePtr<X509>(X509_parse_from_buffer(buffer.get()));
	}

	// static
	int TlsConnectionImpl::SSLSetCertVerifyCb(X509_STORE_CTX* ctx, void* opaque) {
	auto* p = reinterpret_cast<TlsConnectionImpl*>(opaque);
	return p->cert_verify_cb_(ctx);
	}

	// static
	int TlsConnectionImpl::SSLSetCertCb(SSL* ssl, void* opaque) {
	auto* p = reinterpret_cast<TlsConnectionImpl*>(opaque);
	return p->set_cert_cb_(ssl);
	}

	bool TlsConnectionImpl::AddTrustedCertificate(std::string_view cert) {
	// Create X509 buffer from the certificate string
	auto buf = X509FromBuffer(BufferFromPEM(cert));
	if (buf == nullptr) {
	LOG(ERROR) << RoleToString() << "Failed to create a X509 buffer for the certificate.";
	return false;
	}
	known_certificates_.push_back(std::move(buf));
	return true;
	}

	void TlsConnectionImpl::SetCertVerifyCallback(CertVerifyCb cb) {
	cert_verify_cb_ = cb;
	}

	void TlsConnectionImpl::SetCertificateCallback(SetCertCb cb) {
	set_cert_cb_ = cb;
	}

	void TlsConnectionImpl::SetClientCAList(STACK_OF(X509_NAME) * ca_list) {
	CHECK(role_ == Role::Server);
	ca_list_.reset(ca_list != nullptr ? SSL_dup_CA_list(ca_list) : nullptr);
	}

	std::vector<uint8_t> TlsConnectionImpl::ExportKeyingMaterial(size_t length) {
	if (ssl_.get() == nullptr) {
	return {};
	}

	std::vector<uint8_t> out(length);
	if (SSL_export_keying_material(ssl_.get(), out.data(), out.size(), kExportedKeyLabel,
	sizeof(kExportedKeyLabel), nullptr, 0, false) == 0) {
	return {};
	}
	return out;
	}

	void TlsConnectionImpl::EnableClientPostHandshakeCheck(bool enable) {
	client_verify_post_handshake_ = enable;
	}

	TlsConnection::TlsError TlsConnectionImpl::GetFailureReason(int err) {
	switch (ERR_GET_REASON(err)) {
	case SSL_R_SSLV3_ALERT_BAD_CERTIFICATE:
	case SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE:
	case SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED:
	case SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED:
	case SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN:
	case SSL_R_TLSV1_ALERT_ACCESS_DENIED:
	case SSL_R_TLSV1_ALERT_UNKNOWN_CA:
	case SSL_R_TLSV1_CERTIFICATE_REQUIRED:
	return TlsError::PeerRejectedCertificate;
	case SSL_R_CERTIFICATE_VERIFY_FAILED:
	return TlsError::CertificateRejected;
	default:
	return TlsError::UnknownFailure;
	}
	}

	TlsConnection::TlsError TlsConnectionImpl::DoHandshake() {
	LOG(INFO) << RoleToString() << "Starting adbwifi tls handshake";
	ssl_ctx_.reset(SSL_CTX_new(TLS_method()));
	// TODO: Remove set_max_proto_version() once external/boringssl is updated
	// past
	// https://boringssl.googlesource.com/boringssl/+/58d56f4c59969a23e5f52014e2651c76fea2f877
	if (ssl_ctx_.get() == nullptr \|\|
	!SSL_CTX_set_min_proto_version(ssl_ctx_.get(), TLS1_3_VERSION) \|\|
	!SSL_CTX_set_max_proto_version(ssl_ctx_.get(), TLS1_3_VERSION)) {
	LOG(ERROR) << RoleToString() << "Failed to create SSL context";
	return TlsError::UnknownFailure;
	}

	// Register user-supplied known certificates
	for (auto const& cert : known_certificates_) {
	if (X509_STORE_add_cert(SSL_CTX_get_cert_store(ssl_ctx_.get()), cert.get()) == 0) {
	LOG(ERROR) << RoleToString() << "Unable to add certificates into the X509_STORE";
	return TlsError::UnknownFailure;
	}
	}

	// Custom certificate verification
	if (cert_verify_cb_) {
	SSL_CTX_set_cert_verify_callback(ssl_ctx_.get(), SSLSetCertVerifyCb, this);
	}

	// set select certificate callback, if any.
	if (set_cert_cb_) {
	SSL_CTX_set_cert_cb(ssl_ctx_.get(), SSLSetCertCb, this);
	}

	// Server-allowed client CA list
	if (ca_list_ != nullptr) {
	bssl::UniquePtr<STACK_OF(X509_NAME)> names(SSL_dup_CA_list(ca_list_.get()));
	SSL_CTX_set_client_CA_list(ssl_ctx_.get(), names.release());
	}

	// Register our certificate and private key.
	std::vector<CRYPTO_BUFFER*> cert_chain = {
	cert_.get(),
	};
	if (!SSL_CTX_set_chain_and_key(ssl_ctx_.get(), cert_chain.data(), cert_chain.size(),
	priv_key_.get(), nullptr)) {
	LOG(ERROR) << RoleToString()
	<< "Unable to register the certificate chain file and private key ["
	<< SSLErrorString() << "]";
	Invalidate();
	return TlsError::UnknownFailure;
	}

	SSL_CTX_set_verify(ssl_ctx_.get(), SSL_VERIFY_PEER \| SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);

	// Okay! Let's try to do the handshake!
	ssl_.reset(SSL_new(ssl_ctx_.get()));
	if (!SSL_set_fd(ssl_.get(), fd_.get())) {
	LOG(ERROR) << RoleToString() << "SSL_set_fd failed. [" << SSLErrorString() << "]";
	return TlsError::UnknownFailure;
	}

	switch (role_) {
	case Role::Server:
	SSL_set_accept_state(ssl_.get());
	break;
	case Role::Client:
	SSL_set_connect_state(ssl_.get());
	break;
	}
	if (SSL_do_handshake(ssl_.get()) != 1) {
	LOG(ERROR) << RoleToString() << "Handshake failed in SSL_accept/SSL_connect ["
	<< SSLErrorString() << "]";
	auto sslerr = ERR_get_error();
	Invalidate();
	return GetFailureReason(sslerr);
	}

	if (client_verify_post_handshake_ && role_ == Role::Client) {
	uint8_t check;
	// Try to peek one byte for any failures. This assumes on success that
	// the server actually sends something.
	if (SSL_peek(ssl_.get(), &check, 1) <= 0) {
	LOG(ERROR) << RoleToString() << "Post-handshake SSL_peek failed [" << SSLErrorString()
	<< "]";
	auto sslerr = ERR_get_error();
	Invalidate();
	return GetFailureReason(sslerr);
	}
	}

	LOG(INFO) << RoleToString() << "Handshake succeeded.";
	return TlsError::Success;
	}

	void TlsConnectionImpl::Invalidate() {
	ssl_.reset();
	ssl_ctx_.reset();
	}

	std::vector<uint8_t> TlsConnectionImpl::ReadFully(size_t size) {
	std::vector<uint8_t> buf(size);
	if (!ReadFully(buf.data(), buf.size())) {
	return {};
	}

	return buf;
	}

	bool TlsConnectionImpl::ReadFully(void* buf, size_t size) {
	CHECK_GT(size, 0U);
	if (!ssl_) {
	LOG(ERROR) << RoleToString() << "Tried to read on a null SSL connection";
	return false;
	}

	size_t offset = 0;
	uint8_t* p8 = reinterpret_cast<uint8_t*>(buf);
	while (size > 0) {
	int bytes_read =
	SSL_read(ssl_.get(), p8 + offset, std::min(static_cast<size_t>(INT_MAX), size));
	if (bytes_read <= 0) {
	LOG(ERROR) << RoleToString() << "SSL_read failed [" << SSLErrorString() << "]";
	return false;
	}
	size -= bytes_read;
	offset += bytes_read;
	}
	return true;
	}

	bool TlsConnectionImpl::WriteFully(std::string_view data) {
	CHECK(!data.empty());
	if (!ssl_) {
	LOG(ERROR) << RoleToString() << "Tried to read on a null SSL connection";
	return false;
	}

	while (!data.empty()) {
	int bytes_out = SSL_write(ssl_.get(), data.data(),
	std::min(static_cast<size_t>(INT_MAX), data.size()));
	if (bytes_out <= 0) {
	LOG(ERROR) << RoleToString() << "SSL_write failed [" << SSLErrorString() << "]";
	return false;
	}
	data = data.substr(bytes_out);
	}
	return true;
	}
	} // namespace

	// static
	std::unique_ptr<TlsConnection> TlsConnection::Create(TlsConnection::Role role,
	std::string_view cert,
	std::string_view priv_key, borrowed_fd fd) {
	CHECK(!cert.empty());
	CHECK(!priv_key.empty());

	return std::make_unique<TlsConnectionImpl>(role, cert, priv_key, fd);
	}

	// static
	bool TlsConnection::SetCertAndKey(SSL* ssl, std::string_view cert, std::string_view priv_key) {
	CHECK(ssl);
	// Note: declaring these in local scope is okay because
	// SSL_set_chain_and_key will increase the refcount (bssl::UpRef).
	auto x509_cert = TlsConnectionImpl::BufferFromPEM(cert);
	auto evp_pkey = TlsConnectionImpl::EvpPkeyFromPEM(priv_key);
	if (x509_cert == nullptr \|\| evp_pkey == nullptr) {
	return false;
	}

	std::vector<CRYPTO_BUFFER*> cert_chain = {
	x509_cert.get(),
	};
	if (!SSL_set_chain_and_key(ssl, cert_chain.data(), cert_chain.size(), evp_pkey.get(),
	nullptr)) {
	LOG(ERROR) << "SSL_set_chain_and_key failed";
	return false;
	}

	return true;
	}

	} // namespace tls
	} // namespace adb