ClickHouse/dbms/programs/server/MySQLHandler.cpp
2019-07-28 03:55:46 +03:00

391 lines
15 KiB
C++

#include "MySQLHandler.h"
#include <limits>
#include <ext/scope_guard.h>
#include <openssl/rsa.h>
#include <Columns/ColumnVector.h>
#include <Common/config_version.h>
#include <Common/NetException.h>
#include <Common/OpenSSLHelpers.h>
#include <Core/MySQLProtocol.h>
#include <Core/NamesAndTypes.h>
#include <DataStreams/copyData.h>
#include <Interpreters/executeQuery.h>
#include <IO/ReadBufferFromPocoSocket.h>
#include <IO/ReadBufferFromString.h>
#include <IO/WriteBufferFromPocoSocket.h>
#include <Poco/Crypto/CipherFactory.h>
#include <Poco/Crypto/RSAKey.h>
#include <Poco/Net/SecureStreamSocket.h>
#include <Poco/Net/SSLManager.h>
#include <Storages/IStorage.h>
namespace DB
{
using namespace MySQLProtocol;
using Poco::Net::SecureStreamSocket;
using Poco::Net::SSLManager;
namespace ErrorCodes
{
extern const int MYSQL_CLIENT_INSUFFICIENT_CAPABILITIES;
extern const int OPENSSL_ERROR;
}
MySQLHandler::MySQLHandler(IServer & server_, const Poco::Net::StreamSocket & socket_, RSA & public_key, RSA & private_key, bool ssl_enabled, size_t connection_id)
: Poco::Net::TCPServerConnection(socket_)
, server(server_)
, log(&Poco::Logger::get("MySQLHandler"))
, connection_context(server.context())
, connection_id(connection_id)
, public_key(public_key)
, private_key(private_key)
{
server_capability_flags = CLIENT_PROTOCOL_41 | CLIENT_SECURE_CONNECTION | CLIENT_PLUGIN_AUTH | CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA | CLIENT_CONNECT_WITH_DB | CLIENT_DEPRECATE_EOF;
if (ssl_enabled)
server_capability_flags |= CLIENT_SSL;
}
void MySQLHandler::run()
{
connection_context.makeSessionContext();
connection_context.setDefaultFormat("MySQLWire");
in = std::make_shared<ReadBufferFromPocoSocket>(socket());
out = std::make_shared<WriteBufferFromPocoSocket>(socket());
packet_sender = std::make_shared<PacketSender>(*in, *out, connection_context.mysql.sequence_id);
try
{
String scramble = generateScramble();
Handshake handshake(server_capability_flags, connection_id, VERSION_STRING + String("-") + VERSION_NAME, Authentication::Native, scramble + '\0');
packet_sender->sendPacket<Handshake>(handshake, true);
LOG_TRACE(log, "Sent handshake");
HandshakeResponse handshake_response;
finishHandshake(handshake_response);
connection_context.mysql.client_capabilities = handshake_response.capability_flags;
if (handshake_response.max_packet_size)
connection_context.mysql.max_packet_size = handshake_response.max_packet_size;
if (!connection_context.mysql.max_packet_size)
connection_context.mysql.max_packet_size = MAX_PACKET_LENGTH;
LOG_DEBUG(log, "Capabilities: " << handshake_response.capability_flags
<< "\nmax_packet_size: "
<< handshake_response.max_packet_size
<< "\ncharacter_set: "
<< handshake_response.character_set
<< "\nuser: "
<< handshake_response.username
<< "\nauth_response length: "
<< handshake_response.auth_response.length()
<< "\nauth_response: "
<< handshake_response.auth_response
<< "\ndatabase: "
<< handshake_response.database
<< "\nauth_plugin_name: "
<< handshake_response.auth_plugin_name);
client_capability_flags = handshake_response.capability_flags;
if (!(client_capability_flags & CLIENT_PROTOCOL_41))
throw Exception("Required capability: CLIENT_PROTOCOL_41.", ErrorCodes::MYSQL_CLIENT_INSUFFICIENT_CAPABILITIES);
if (!(client_capability_flags & CLIENT_PLUGIN_AUTH))
throw Exception("Required capability: CLIENT_PLUGIN_AUTH.", ErrorCodes::MYSQL_CLIENT_INSUFFICIENT_CAPABILITIES);
authenticate(handshake_response, scramble);
OK_Packet ok_packet(0, handshake_response.capability_flags, 0, 0, 0);
packet_sender->sendPacket(ok_packet, true);
while (true)
{
packet_sender->resetSequenceId();
PacketPayloadReadBuffer payload = packet_sender->getPayload();
char command = 0;
payload.readStrict(command);
// For commands which are executed without MemoryTracker.
LimitReadBuffer limited_payload(payload, 10000, true, "too long MySQL packet.");
LOG_DEBUG(log, "Received command: " << static_cast<int>(static_cast<unsigned char>(command)) << ". Connection id: " << connection_id << ".");
try
{
switch (command)
{
case COM_QUIT:
return;
case COM_INIT_DB:
comInitDB(limited_payload);
break;
case COM_QUERY:
comQuery(payload);
break;
case COM_FIELD_LIST:
comFieldList(limited_payload);
break;
case COM_PING:
comPing();
break;
default:
throw Exception(Poco::format("Command %d is not implemented.", command), ErrorCodes::NOT_IMPLEMENTED);
}
}
catch (const NetException & exc)
{
log->log(exc);
throw;
}
catch (const Exception & exc)
{
log->log(exc);
packet_sender->sendPacket(ERR_Packet(exc.code(), "00000", exc.message()), true);
}
}
}
catch (const Poco::Exception & exc)
{
log->log(exc);
}
}
/** Reads 3 bytes, finds out whether it is SSLRequest or HandshakeResponse packet, starts secure connection, if it is SSLRequest.
* Reading is performed from socket instead of ReadBuffer to prevent reading part of SSL handshake.
* If we read it from socket, it will be impossible to start SSL connection using Poco. Size of SSLRequest packet payload is 32 bytes, thus we can read at most 36 bytes.
*/
void MySQLHandler::finishHandshake(MySQLProtocol::HandshakeResponse & packet)
{
size_t packet_size = PACKET_HEADER_SIZE + SSL_REQUEST_PAYLOAD_SIZE;
/// Buffer for SSLRequest or part of HandshakeResponse.
char buf[packet_size];
size_t pos = 0;
/// Reads at least count and at most packet_size bytes.
auto read_bytes = [this, &buf, &pos, &packet_size](size_t count) -> void {
while (pos < count)
{
int ret = socket().receiveBytes(buf + pos, packet_size - pos);
if (ret == 0)
{
throw Exception("Cannot read all data. Bytes read: " + std::to_string(pos) + ". Bytes expected: 3.", ErrorCodes::CANNOT_READ_ALL_DATA);
}
pos += ret;
}
};
read_bytes(3); /// We can find out whether it is SSLRequest of HandshakeResponse by first 3 bytes.
size_t payload_size = unalignedLoad<uint32_t>(buf) & 0xFFFFFFu;
LOG_TRACE(log, "payload size: " << payload_size);
if (payload_size == SSL_REQUEST_PAYLOAD_SIZE)
{
read_bytes(packet_size); /// Reading rest SSLRequest.
SSLRequest ssl_request;
ReadBufferFromMemory payload(buf, pos);
payload.ignore(PACKET_HEADER_SIZE);
ssl_request.readPayload(payload);
connection_context.mysql.client_capabilities = ssl_request.capability_flags;
connection_context.mysql.max_packet_size = ssl_request.max_packet_size ? ssl_request.max_packet_size : MAX_PACKET_LENGTH;
secure_connection = true;
ss = std::make_shared<SecureStreamSocket>(SecureStreamSocket::attach(socket(), SSLManager::instance().defaultServerContext()));
in = std::make_shared<ReadBufferFromPocoSocket>(*ss);
out = std::make_shared<WriteBufferFromPocoSocket>(*ss);
connection_context.mysql.sequence_id = 2;
packet_sender = std::make_shared<PacketSender>(*in, *out, connection_context.mysql.sequence_id);
packet_sender->max_packet_size = connection_context.mysql.max_packet_size;
packet_sender->receivePacket(packet); /// Reading HandshakeResponse from secure socket.
}
else
{
/// Reading rest of HandshakeResponse.
packet_size = PACKET_HEADER_SIZE + payload_size;
WriteBufferFromOwnString buf_for_handshake_response;
buf_for_handshake_response.write(buf, pos);
copyData(*packet_sender->in, buf_for_handshake_response, packet_size - pos);
ReadBufferFromString payload(buf_for_handshake_response.str());
payload.ignore(PACKET_HEADER_SIZE);
packet.readPayload(payload);
packet_sender->sequence_id++;
}
}
String MySQLHandler::generateScramble()
{
String scramble(MySQLProtocol::SCRAMBLE_LENGTH, 0);
Poco::RandomInputStream generator;
for (size_t i = 0; i < scramble.size(); i++)
{
generator >> scramble[i];
}
return scramble;
}
void MySQLHandler::authenticate(const HandshakeResponse & handshake_response, const String & scramble)
{
String auth_response;
AuthSwitchResponse response;
if (handshake_response.auth_plugin_name != Authentication::SHA256)
{
/** Native authentication sent 20 bytes + '\0' character = 21 bytes.
* This plugin must do the same to stay consistent with historical behavior if it is set to operate as a default plugin.
* https://github.com/mysql/mysql-server/blob/8.0/sql/auth/sql_authentication.cc#L3994
*/
packet_sender->sendPacket(AuthSwitchRequest(Authentication::SHA256, scramble + '\0'), true);
if (in->eof())
throw Exception(
"Client doesn't support authentication method " + String(Authentication::SHA256) + " used by ClickHouse",
ErrorCodes::MYSQL_CLIENT_INSUFFICIENT_CAPABILITIES);
packet_sender->receivePacket(response);
auth_response = response.value;
LOG_TRACE(log, "Authentication method mismatch.");
}
else
{
auth_response = handshake_response.auth_response;
LOG_TRACE(log, "Authentication method match.");
}
if (auth_response == "\1")
{
LOG_TRACE(log, "Client requests public key.");
BIO * mem = BIO_new(BIO_s_mem());
SCOPE_EXIT(BIO_free(mem));
if (PEM_write_bio_RSA_PUBKEY(mem, &public_key) != 1)
{
throw Exception("Failed to write public key to memory. Error: " + getOpenSSLErrors(), ErrorCodes::OPENSSL_ERROR);
}
char * pem_buf = nullptr;
long pem_size = BIO_get_mem_data(mem, &pem_buf);
String pem(pem_buf, pem_size);
LOG_TRACE(log, "Key: " << pem);
AuthMoreData data(pem);
packet_sender->sendPacket(data, true);
packet_sender->receivePacket(response);
auth_response = response.value;
}
else
{
LOG_TRACE(log, "Client didn't request public key.");
}
String password;
/** Decrypt password, if it's not empty.
* The original intention was that the password is a string[NUL] but this never got enforced properly so now we have to accept that
* an empty packet is a blank password, thus the check for auth_response.empty() has to be made too.
* https://github.com/mysql/mysql-server/blob/8.0/sql/auth/sql_authentication.cc#L4017
*/
if (!secure_connection && !auth_response.empty() && auth_response != String("\0", 1))
{
LOG_TRACE(log, "Received nonempty password");
auto ciphertext = reinterpret_cast<unsigned char *>(auth_response.data());
unsigned char plaintext[RSA_size(&private_key)];
int plaintext_size = RSA_private_decrypt(auth_response.size(), ciphertext, plaintext, &private_key, RSA_PKCS1_OAEP_PADDING);
if (plaintext_size == -1)
{
throw Exception("Failed to decrypt auth data. Error: " + getOpenSSLErrors(), ErrorCodes::OPENSSL_ERROR);
}
password.resize(plaintext_size);
for (int i = 0; i < plaintext_size; i++)
{
password[i] = plaintext[i] ^ static_cast<unsigned char>(scramble[i % scramble.size()]);
}
}
else if (secure_connection)
{
password = auth_response;
}
else
{
LOG_TRACE(log, "Received empty password");
}
if (!password.empty() && password.back() == 0)
{
password.pop_back();
}
try
{
connection_context.setUser(handshake_response.username, password, socket().address(), "");
if (!handshake_response.database.empty()) connection_context.setCurrentDatabase(handshake_response.database);
connection_context.setCurrentQueryId("");
LOG_INFO(log, "Authentication for user " << handshake_response.username << " succeeded.");
}
catch (const Exception & exc)
{
LOG_ERROR(log, "Authentication for user " << handshake_response.username << " failed.");
packet_sender->sendPacket(ERR_Packet(exc.code(), "00000", exc.message()), true);
throw;
}
}
void MySQLHandler::comInitDB(ReadBuffer & payload)
{
String database;
readStringUntilEOF(database, payload);
LOG_DEBUG(log, "Setting current database to " << database);
connection_context.setCurrentDatabase(database);
packet_sender->sendPacket(OK_Packet(0, client_capability_flags, 0, 0, 1), true);
}
void MySQLHandler::comFieldList(ReadBuffer & payload)
{
ComFieldList packet;
packet.readPayload(payload);
String database = connection_context.getCurrentDatabase();
StoragePtr tablePtr = connection_context.getTable(database, packet.table);
for (const NameAndTypePair & column: tablePtr->getColumns().getAll())
{
ColumnDefinition column_definition(
database, packet.table, packet.table, column.name, column.name, CharacterSet::binary, 100, ColumnType::MYSQL_TYPE_STRING, 0, 0
);
packet_sender->sendPacket(column_definition);
}
packet_sender->sendPacket(OK_Packet(0xfe, client_capability_flags, 0, 0, 0), true);
}
void MySQLHandler::comPing()
{
packet_sender->sendPacket(OK_Packet(0x0, client_capability_flags, 0, 0, 0), true);
}
void MySQLHandler::comQuery(ReadBuffer & payload)
{
bool with_output = false;
std::function<void(const String &)> set_content_type = [&with_output](const String &) -> void {
with_output = true;
};
const String query("select ''");
ReadBufferFromString empty_select(query);
bool should_replace = false;
// Translate query from MySQL to ClickHouse.
// This is a temporary workaround until ClickHouse supports the syntax "@@var_name".
if (std::string(payload.position(), payload.buffer().end()) == "select @@version_comment limit 1") // MariaDB client starts session with that query
{
should_replace = true;
}
executeQuery(should_replace ? empty_select : payload, *out, true, connection_context, set_content_type, nullptr);
if (!with_output)
packet_sender->sendPacket(OK_Packet(0x00, client_capability_flags, 0, 0, 0), true);
}
}