MDEV-9659 : AWS KMS encryption plugin

2 files changed, 738 insertions, 0 deletions

diff --git a/plugin/aws_key_management/CMakeLists.txt b/plugin/aws_key_management/CMakeLists.txt
new file mode 100644
index 00000000000..6b491186576
--- /dev/null
+++ b/plugin/aws_key_management/CMakeLists.txt
@@ -0,0 +1,151 @@
+# We build parts of AWS C++ SDK as CMake external project
+# The restrictions of the SDK (https://github.com/awslabs/aws-sdk-cpp/blob/master/README.md)
+# are
+ 
+# - OS : Windows,Linux or OSX
+# - C++11 compiler : VS2013+, gcc 4.7+, clang 3.3+
+# - libcurl development package needs to be present on Unixes
+#
+# If we build SDK outselves, we'll need require GIT to be present on the build machine
+
+
+# Give message why the building this plugin is skipped (only if -DVERBOSE is defined)
+# or if plugin is explicitely requested to build. Then bail out.
+MACRO(SKIP_AWS_PLUGIN msg)
+  IF(VERBOSE OR "${PLUGIN_AWS_KEY_MANAGEMENT}" MATCHES "^(STATIC|DYNAMIC)$")
+    MESSAGE(STATUS "Skip aws_key_management - ${msg}")
+  ENDIF()
+  RETURN()
+ENDMACRO()
+
+
+# This plugin needs recent C++ compilers (AWS C++ SDK header files are using C++11 features)
+SET(CXX11_FLAGS)
+SET(OLD_COMPILER_MSG "AWS SDK requires c++11 -capable compiler (minimal supported versions are g++ 4.7, clang 3.3, VS2103)")
+
+IF(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
+  EXECUTE_PROCESS(COMMAND ${CMAKE_CXX_COMPILER} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
+  IF (GCC_VERSION VERSION_LESS 4.8)
+    SKIP_AWS_PLUGIN("${OLD_COMPILER_MSG}")
+  ENDIF()
+  SET(CXX11_FLAGS "-std=c++11")
+ELSEIF (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  IF ((CMAKE_CXX_COMPILER_VERSION AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS  3.3) OR
+     (CLANG_VERSION_STRING AND CLANG_VERSION_STRING VERSION_LESS  3.3))
+    SKIP_AWS_PLUGIN("${OLD_COMPILER_MSG}")
+  ENDIF()
+  SET(CXX11_FLAGS "-stdlib=libc++")
+ELSEIF(MSVC)
+  IF (MSVC_VERSION LESS 1800)
+    SKIP_AWS_PLUGIN("${OLD_COMPILER_MSG}")
+  ENDIF()
+ELSE()
+  SKIP_AWS_PLUGIN("Compiler not supported by AWS C++ SDK")
+ENDIF()
+
+IF (NOT(WIN32 OR APPLE  OR (CMAKE_SYSTEM_NAME MATCHES "Linux")))
+  SKIP_AWS_PLUGIN("OS unsupported by AWS SDK")
+ENDIF()
+
+
+# Figure out where AWS installs SDK libraries 
+# The below is defined in AWS SDK's CMakeLists.txt 
+# (and their handling is weird, every OS has special install directory)
+IF(WIN32)
+  SET(SDK_INSTALL_BINARY_PREFIX "windows")
+ELSEIF(APPLE)
+  SET(SDK_INSTALL_BINARY_PREFIX "mac")
+ELSEIF(UNIX)
+  SET(SDK_INSTALL_BINARY_PREFIX "linux")
+ENDIF()
+IF(NOT APPLE)
+ IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
+   SET(SDK_INSTALL_BINARY_PREFIX "${SDK_INSTALL_BINARY_PREFIX}/intel64")
+  ELSE()
+   SET(SDK_INSTALL_BINARY_PREFIX "${SDK_INSTALL_BINARY_PREFIX}/ia32")
+  ENDIF()
+ENDIF()
+IF(CMAKE_CONFIGURATION_TYPES)
+  SET(SDK_INSTALL_BINARY_PREFIX "${SDK_INSTALL_BINARY_PREFIX}/${CMAKE_CFG_INTDIR}")
+ENDIF()
+
+FIND_LIBRARY(AWS_CPP_SDK_CORE NAMES aws-cpp-sdk-core PATH_SUFFIXES  "${SDK_INSTALL_BINARY_PREFIX}")
+FIND_LIBRARY(AWS_CPP_SDK_KMS NAMES aws-cpp-sdk-core PATH_SUFFIXES  "${SDK_INSTALL_BINARY_PREFIX}")
+SET(CMAKE_REQUIRED_FLAGS ${CXX11_FLAGS})
+CHECK_INCLUDE_FILE_CXX(aws/kms/KMSClient.h HAVE_AWS_HEADERS)
+
+IF(AWS_CPP_SDK_CORE AND AWS_CPP_SDK_KMS AND HAVE_AWS_HEADERS)
+  # AWS C++ SDK installed 
+  SET(AWS_SDK_LIBS ${AWS_CPP_SDK_CORE} ${AWS_CPP_SDK_KMS})
+ELSE()
+  # Build from source, using ExternalProject_Add
+  IF(CMAKE_VERSION VERSION_LESS "2.8.8")
+    SKIP_AWS_PLUGIN("CMake is too old")
+  ENDIF()
+  FIND_PACKAGE(Git)
+  IF(NOT GIT_FOUND)
+    SKIP_AWS_PLUGIN("no GIT")
+  ENDIF()
+  INCLUDE(ExternalProject)
+  IF(UNIX)
+    FIND_PACKAGE(CURL)
+    IF(NOT CURL_FOUND)
+      SKIP_AWS_PLUGIN("AWS C++ SDK requires libcurl development package")
+    ENDIF()
+    SET(PIC_FLAG -fPIC)
+  ENDIF()
+  IF(MSVC)
+    SET(EXTRA_SDK_CMAKE_FLAGS -DCMAKE_CXX_FLAGS_DEBUGOPT="" -DCMAKE_EXE_LINKER_FLAGS_DEBUGOPT="" -DCMAKE_CXX_FLAGS=/wd4592)
+  ENDIF()
+  IF(CMAKE_CXX_COMPILER)
+   SET(EXTRA_SDK_CMAKE_FLAGS ${EXTRA_SDK_CMAKE_FLAGS} -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER})
+  ENDIF()
+
+  # Relax AWS C++ SDK unreasonably high requirements for CMake version. Use replace utility (from MariaDB build)
+  # to patch their CMakeLists.txt
+  SET(AWS_SDK_PATCH_COMMAND )
+  ExternalProject_Add(
+    aws_sdk_cpp
+    GIT_REPOSITORY "https://github.com/awslabs/aws-sdk-cpp.git"
+    GIT_TAG "0.9.6" # single tag
+    UPDATE_COMMAND ""
+    PATCH_COMMAND replace 3.1.2 2.8 -- ${CMAKE_BINARY_DIR}/aws-sdk-cpp/CMakeLists.txt
+    SOURCE_DIR "${CMAKE_BINARY_DIR}/aws-sdk-cpp"
+    CMAKE_ARGS 
+    -DBUILD_ONLY=aws-cpp-sdk-kms -DSTATIC_LINKING=1 
+    "-DCMAKE_CXX_FLAGS_DEBUG=${CMAKE_CXX_FLAGS_DEBUG} ${PIC_FLAG}"
+    "-DCMAKE_CXX_FLAGS_RELWITHDEBINFO=${CMAKE_CXX_FLAGS_RELWITHDEBINFO} ${PIC_FLAG}"
+    "-DCMAKE_CXX_FLAGS_RELEASE=${CMAKE_CXX_FLAGS_RELEASE} ${PIC_FLAG}"
+    "-DCMAKE_CXX_FLAGS_MINSIZEREL=${CMAKE_CXX_FLAGS_MINSIZEREL} ${PIC_FLAG}"
+    ${EXTRA_SDK_CMAKE_FLAGS}
+    -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/aws_sdk_cpp
+    TEST_COMMAND ""
+  )
+
+  # We do not need to build the whole SDK , just 2 of its libs
+  set(AWS_SDK_LIBS aws-cpp-sdk-core aws-cpp-sdk-kms)
+  FOREACH(lib ${AWS_SDK_LIBS})
+    ADD_LIBRARY(${lib} STATIC IMPORTED GLOBAL)
+    ADD_DEPENDENCIES(${lib} aws_sdk_cpp)
+    SET(loc "${CMAKE_BINARY_DIR}/aws_sdk_cpp/lib/${SDK_INSTALL_BINARY_PREFIX}/${CMAKE_STATIC_LIBRARY_PREFIX}${lib}${CMAKE_STATIC_LIBRARY_SUFFIX}")
+    SET_TARGET_PROPERTIES(${lib} PROPERTIES IMPORTED_LOCATION ${loc})
+    IF(WIN32)
+      SET_TARGET_PROPERTIES(${lib} PROPERTIES IMPORTED_LINK_INTERFACE_LIBRARIES "bcrypt;winhttp;wininet;userenv")
+    ELSE()
+      SET_TARGET_PROPERTIES(${lib} PROPERTIES IMPORTED_LINK_INTERFACE_LIBRARIES "${SSL_LIBRARIES};${CURL_LIBRARIES}")
+    ENDIF()  
+  ENDFOREACH()
+
+  IF(CMAKE_SYSTEM_NAME MATCHES "Linux")
+    # Need whole-archive , otherwise static libraries are not linked
+    SET(AWS_SDK_LIBS -Wl,--whole-archive ${AWS_SDK_LIBS} -Wl,--no-whole-archive)
+  ENDIF()
+  SET_TARGET_PROPERTIES(aws_sdk_cpp PROPERTIES EXCLUDE_FROM_ALL TRUE)
+  INCLUDE_DIRECTORIES(${CMAKE_BINARY_DIR}/aws_sdk_cpp/include)
+ENDIF()
+
+SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  ${CXX11_FLAGS}")
+MYSQL_ADD_PLUGIN(aws_key_management aws_key_management_plugin.cc
+                 COMPONENT aws-key-management
+                 LINK_LIBRARIES ${AWS_SDK_LIBS}
+                 DISABLED)
diff --git a/plugin/aws_key_management/aws_key_management_plugin.cc b/plugin/aws_key_management/aws_key_management_plugin.cc
new file mode 100644
index 00000000000..3913d2c3145
--- /dev/null
+++ b/plugin/aws_key_management/aws_key_management_plugin.cc
@@ -0,0 +1,587 @@
+/*
+  Copyright (c) 2016 MariaDB Corporation
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; version 2 of the License.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+
+#include <my_global.h>
+#include <my_pthread.h>
+#include <my_sys.h>
+#include <my_dir.h>
+#include <mysql/plugin_encryption.h>
+#include <my_crypt.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <mysqld_error.h>
+#include <base64.h>
+#include <map>
+#include <algorithm>
+#include <string>
+#include <vector>
+#include <iterator>
+#include <sstream>
+#include <fstream>
+
+#include <aws/core/client/AWSError.h>
+#include <aws/core/utils/logging/AWSLogging.h>
+#include <aws/core/utils/logging/ConsoleLogSystem.h>
+#include <aws/kms/KMSClient.h>
+#include <aws/kms/model/DecryptRequest.h>
+#include <aws/kms/model/DecryptResult.h>
+#include <aws/kms/model/GenerateDataKeyWithoutPlaintextRequest.h>
+#include <aws/kms/model/GenerateDataKeyWithoutPlaintextResult.h>
+#include <aws/core/utils/Outcome.h>
+
+using namespace std;
+using namespace Aws::KMS;
+using namespace Aws::KMS::Model;
+using namespace Aws::Utils::Logging;
+extern void sql_print_error(const char *format, ...);
+extern void sql_print_warning(const char *format, ...);
+extern void sql_print_information(const char *format, ...);
+
+
+/* Plaintext key info struct */
+struct KEY_INFO
+{
+  unsigned int  key_id;
+  unsigned int  key_version;
+  unsigned int  length;
+  unsigned char data[MY_AES_MAX_KEY_LENGTH];
+  bool          load_failed; /* if true, do not attempt to reload?*/
+public:
+  KEY_INFO() : key_id(0), key_version(0), length(0), load_failed(false){};
+};
+#define KEY_ID_AND_VERSION(key_id,version) ((longlong)key_id << 32 | version)
+
+/* Cache for the latest version, per key id */
+static std::map<uint, uint> latest_version_cache;
+
+/* Cache for plaintext keys */
+static std::map<ulonglong, KEY_INFO>  key_info_cache;
+
+static const char *key_spec_names[]={ "AES_128", "AES_256", 0 };
+
+/* Plugin variables */
+static char* master_key_id;
+static unsigned long key_spec;
+static unsigned long log_level;
+static int rotate_key;
+
+/* AWS functionality*/
+static int aws_decrypt_key(const char *path, KEY_INFO *info);
+static int aws_generate_datakey(uint key_id, uint version);
+
+static int extract_id_and_version(const char *name, uint *id, uint *ver);
+static unsigned int get_latest_key_version(unsigned int key_id);
+static unsigned int get_latest_key_version_nolock(unsigned int key_id);
+static int load_key(KEY_INFO *info);
+
+/* Mutex to serialize access to caches */
+static mysql_mutex_t mtx;
+
+#ifdef HAVE_PSI_INTERFACE
+static uint mtx_key;
+static PSI_mutex_info mtx_info = {&mtx_key, "mtx", 0};
+#endif
+
+static Aws::KMS::KMSClient *client;
+
+/* Redirect AWS trace to error log */
+class  MySQLLogSystem : public Aws::Utils::Logging::FormattedLogSystem
+{
+public:
+
+  using Base = FormattedLogSystem;
+  MySQLLogSystem(LogLevel logLevel) :
+    Base(logLevel) 
+  {
+  }
+  virtual LogLevel GetLogLevel(void) const override
+  {
+    return (LogLevel)log_level;
+  }
+  virtual ~MySQLLogSystem() 
+  {
+  }
+
+protected:
+  virtual void ProcessFormattedStatement(Aws::String&& statement) override
+  {
+#ifdef _WIN32
+    /*
+      On Windows, we can't use C runtime functions to write to stdout,
+      because we compile with static C runtime, so plugin has a stdout
+      different from server. Thus we're using WriteFile().
+    */
+    DWORD nSize= (DWORD)statement.size();
+    DWORD nWritten;
+    const char *s= statement.c_str();
+    HANDLE h= GetStdHandle(STD_OUTPUT_HANDLE);
+
+    WriteFile(h, s, nSize, &nWritten, NULL);
+#else
+    printf("%s", statement.c_str());
+#endif
+  }
+};
+
+
+/* 
+  Plugin initialization.
+
+  Create KMS client and scan datadir to find out which keys and versions
+  are present.
+*/
+static int plugin_init(void *p)
+{
+  DBUG_ENTER("plugin_init");
+  client = new KMSClient();
+  if (!client)
+  {
+    sql_print_error("Can not initialize KMS client");
+    DBUG_RETURN(-1);
+  }
+  InitializeAWSLogging(Aws::MakeShared<MySQLLogSystem>("aws_key_management_plugin", (Aws::Utils::Logging::LogLevel) log_level));
+#ifdef HAVE_PSI_INTERFACE
+  mysql_mutex_register("aws_key_management", &mtx_info, 1);
+#endif
+  mysql_mutex_init(mtx_key, &mtx, NULL);
+
+  MY_DIR *dirp = my_dir(".", MYF(0));
+  if (!dirp)
+  {
+    sql_print_error("Can't scan current directory");
+    DBUG_RETURN(-1);
+  }
+  for (unsigned int i=0; i < dirp->number_of_files; i++)
+  {
+
+    KEY_INFO info;
+    if (extract_id_and_version(dirp->dir_entry[i].name, &info.key_id, &info.key_version) == 0)
+    {
+      key_info_cache[KEY_ID_AND_VERSION(info.key_id, info.key_version)]= info;
+      latest_version_cache[info.key_id]= max(info.key_version, latest_version_cache[info.key_id]);
+    }
+  }
+  my_dirend(dirp);
+  DBUG_RETURN(0);
+}
+
+
+static int plugin_deinit(void *p)
+{
+  DBUG_ENTER("plugin_deinit");
+  latest_version_cache.clear();
+  key_info_cache.clear();
+  mysql_mutex_destroy(&mtx);
+  delete client;
+  ShutdownAWSLogging();
+  DBUG_RETURN(0);
+}
+
+/*  Generate filename to store the ciphered key */
+static void format_keyfile_name(char *buf, size_t size, uint key_id, uint version)
+{
+  snprintf(buf, size, "aws-kms-key.%u.%u", key_id, version);
+}
+
+/* Extract key id and version from file name */
+static int extract_id_and_version(const char *name, uint *id, uint *ver)
+{
+  int len;
+  int n= sscanf(name, "aws-kms-key.%u.%u%n", id, ver, &len);
+  if (n == 2 && *id > 0 && *ver > 0 && len == (int)strlen(name))
+    return 0;
+  return 1;
+}
+
+/*
+  Decrypt key stored in aws-kms-key.<id>.<version>
+  Cache the decrypted key.
+*/
+static int load_key(KEY_INFO *info)
+{
+  int ret;
+  char path[256];
+  DBUG_ENTER("load_key");
+  DBUG_PRINT("enter", ("id=%u,ver=%u", info->key_id, info->key_version));
+  format_keyfile_name(path, sizeof(path), info->key_id, info->key_version);
+  ret= aws_decrypt_key(path, info);
+  if (ret)
+    info->load_failed= true;
+
+  latest_version_cache[info->key_id]= max(latest_version_cache[info->key_id], info->key_version);
+  key_info_cache[KEY_ID_AND_VERSION(info->key_id, info->key_version)]= *info;
+
+  if (!ret)
+  {
+    sql_print_information("AWS KMS plugin: loaded key %u, version %u, key length %u bit",
+      info->key_id, info->key_version,(uint)info->length*8);
+  }
+  else
+  {
+    sql_print_warning("AWS KMS plugin: key %u, version %u could not be decrypted",
+      info->key_id, info->key_version);
+  }
+  DBUG_RETURN(ret);
+}
+
+
+/* 
+  Get latest version for the key.
+
+  If key is not decrypted yet, this function also decrypt the key
+  and error will be returned if decryption fails.
+
+  The reason for that is that Innodb crashes
+   in case errors are returned by get_key(),
+
+  A new key will be created if it does not exist, provided there is
+  valid master_key_id.
+*/
+static unsigned int get_latest_key_version(unsigned int key_id)
+{
+  unsigned int ret;
+  DBUG_ENTER("get_latest_key_version");
+  mysql_mutex_lock(&mtx);
+  ret= get_latest_key_version_nolock(key_id);
+  mysql_mutex_unlock(&mtx);
+  DBUG_PRINT("info", ("key=%u,ret=%u", key_id, ret));
+  DBUG_RETURN(ret);
+}
+
+static unsigned int get_latest_key_version_nolock(unsigned int key_id)
+{
+  KEY_INFO info;
+  uint ver;
+  DBUG_ENTER("get_latest_key_version_nolock");
+  ver= latest_version_cache[key_id];
+  if (ver > 0)
+  {
+    info= key_info_cache[KEY_ID_AND_VERSION(key_id, ver)];
+  }
+  if (info.load_failed)
+  {
+    /* Decryption failed previously, don't retry */
+    DBUG_RETURN(ENCRYPTION_KEY_VERSION_INVALID);
+  }
+  else if (ver > 0)
+  {
+    /* Key exists already, return it*/
+    if (info.length > 0)
+      DBUG_RETURN(ver);
+  }
+  else // (ver == 0)
+  {
+    /* Generate a new key, version 1 */
+    if (!master_key_id[0])
+    {
+      my_printf_error(ER_UNKNOWN_ERROR,
+        "Can't generate encryption key %u, because 'aws_key_management_master_key_id' parameter is not set",
+        MYF(0), key_id);
+      DBUG_RETURN(ENCRYPTION_KEY_VERSION_INVALID);
+    }
+    if (aws_generate_datakey(key_id, 1) != 0)
+      DBUG_RETURN(ENCRYPTION_KEY_VERSION_INVALID);
+    info.key_id= key_id;
+    info.key_version= 1;
+    info.length= 0;
+  }
+
+  if (load_key(&info))
+    DBUG_RETURN(ENCRYPTION_KEY_VERSION_INVALID);
+  DBUG_RETURN(info.key_version);
+}
+
+
+/* 
+  Decrypt a file with KMS
+*/
+static  int aws_decrypt_key(const char *path, KEY_INFO *info)
+{
+  DBUG_ENTER("aws_decrypt_key");
+
+  /* Read file content into memory */
+  ifstream ifs(path, ios::binary | ios::ate);
+  if (!ifs.good())
+  {
+    sql_print_error("can't open file %s", path);
+    DBUG_RETURN(-1);
+  }
+  size_t pos = (size_t)ifs.tellg();
+  if (!pos || pos == SIZE_T_MAX)
+  {
+    sql_print_error("invalid key file %s", path);
+    DBUG_RETURN(-1);
+  }
+  std::vector<char>  contents(pos);
+  ifs.seekg(0, ios::beg);
+  ifs.read(&contents[0], pos);
+
+  /* Decrypt data the with AWS */
+  DecryptRequest request;
+  Aws::Utils::ByteBuffer byteBuffer((unsigned char *)contents.data(), pos);
+  request.SetCiphertextBlob(byteBuffer);
+  DecryptOutcome outcome = client->Decrypt(request);
+  if (!outcome.IsSuccess())
+  {
+    sql_print_error("AWS KMS plugin: Decrypt failed for %s : %s", path,
+      outcome.GetError().GetMessage().c_str());
+    DBUG_RETURN(-1);
+  }
+  Aws::Utils::ByteBuffer plaintext = outcome.GetResult().GetPlaintext();
+  size_t len = plaintext.GetLength();
+
+  if (len > (int)sizeof(info->data))
+  {
+    sql_print_error("AWS KMS plugin: encoding key too large for %s", path);
+    DBUG_RETURN(ENCRYPTION_KEY_BUFFER_TOO_SMALL);
+  }
+  memcpy(info->data, plaintext.GetUnderlyingData(), len);
+  info->length= len;
+  DBUG_RETURN(0);
+}
+
+
+/* Generate a new datakey and store it a file */
+static int aws_generate_datakey(uint keyid, uint version)
+{
+
+  DBUG_ENTER("aws_generate_datakey");
+  GenerateDataKeyWithoutPlaintextRequest request;
+  request.SetKeyId(master_key_id);
+  request.SetKeySpec(DataKeySpecMapper::GetDataKeySpecForName(key_spec_names[key_spec]));
+
+  GenerateDataKeyWithoutPlaintextOutcome outcome;
+  outcome= client->GenerateDataKeyWithoutPlaintext(request);
+  if (!outcome.IsSuccess())
+  {
+    sql_print_error("AWS KMS plugin : GenerateDataKeyWithoutPlaintext failed : %s - %s",
+      outcome.GetError().GetExceptionName().c_str(),
+      outcome.GetError().GetMessage().c_str());
+    DBUG_RETURN(-1);
+  }
+
+  string out;
+  char filename[20];
+  Aws::Utils::ByteBuffer byteBuffer = outcome.GetResult().GetCiphertextBlob();
+
+  format_keyfile_name(filename, sizeof(filename), keyid, version);
+  int fd= my_open(filename, O_RDWR | O_CREAT, 0);
+  if (fd < 0)
+  {
+    sql_print_error("AWS KMS plugin: Can't create file %s", filename);
+    DBUG_RETURN(-1);
+  }
+  size_t len= byteBuffer.GetLength();
+  if (my_write(fd, byteBuffer.GetUnderlyingData(), len, 0) != len)
+  {
+    sql_print_error("AWS KMS plugin: can't write to %s", filename);
+    my_close(fd, 0);
+    my_delete(filename, 0);
+    DBUG_RETURN(-1);
+  }
+  my_close(fd, 0);
+  sql_print_information("AWS KMS plugin: generated encrypted datakey for key id=%u, version=%u",
+    keyid, version);
+  DBUG_RETURN(0);
+}
+
+/* Key rotation  for a single key */
+static int rotate_single_key(uint key_id)
+{
+  uint ver;
+  ver= latest_version_cache[key_id];
+
+  if (!ver)
+  {
+    my_printf_error(ER_UNKNOWN_ERROR, "key %u does not exist", MYF(ME_JUST_WARNING), key_id);
+    return -1;
+  }
+  else if (aws_generate_datakey(key_id, ver + 1))
+  {
+    my_printf_error(ER_UNKNOWN_ERROR, "Could not generate datakey for key id= %u, ver= %u",
+      MYF(ME_JUST_WARNING), key_id, ver);
+    return -1;
+  }
+  else
+  {
+    KEY_INFO info;
+    info.key_id= key_id;
+    info.key_version = ver + 1;
+    if (load_key(&info))
+    {
+      my_printf_error(ER_UNKNOWN_ERROR, "Could not load datakey for key id= %u, ver= %u",
+        MYF(ME_JUST_WARNING), key_id, ver);
+      return -1;
+    }
+  }
+  return 0;
+}
+
+/* Key rotation for all key ids */
+static int rotate_all_keys()
+{
+  int ret= 0;
+  for (map<uint, uint>::iterator it= latest_version_cache.begin(); it != latest_version_cache.end(); it++)
+  {
+    ret= rotate_single_key(it->first);
+    if (ret)
+      break;
+  }
+  return ret;
+}
+
+static void update_rotate(MYSQL_THD, struct st_mysql_sys_var *, void *, const void *val)
+{
+  if (!master_key_id[0])
+  {
+    my_printf_error(ER_UNKNOWN_ERROR,
+      "aws_key_management_master_key_id must be set to generate new data keys", MYF(ME_JUST_WARNING));
+    return;
+  }
+  mysql_mutex_lock(&mtx);
+  rotate_key= *(int *)val;
+  switch (rotate_key)
+  {
+  case 0:
+    break;
+  case -1:
+    rotate_all_keys();
+    break;
+  default:
+    rotate_single_key(rotate_key);
+    break;
+  }
+  rotate_key= 0;
+  mysql_mutex_unlock(&mtx);
+}
+
+static unsigned int get_key(
+  unsigned int key_id,
+  unsigned int version,
+  unsigned char* dstbuf,
+  unsigned int* buflen)
+{
+  KEY_INFO info;
+
+  DBUG_ENTER("get_key");
+  mysql_mutex_lock(&mtx);
+  info= key_info_cache[KEY_ID_AND_VERSION(key_id, version)];
+  if (info.length == 0 && !info.load_failed)
+  {
+    info.key_id= key_id;
+    info.key_version= version;
+    load_key(&info);
+  }
+  mysql_mutex_unlock(&mtx);
+  if (info.load_failed)
+    DBUG_RETURN(ENCRYPTION_KEY_VERSION_INVALID);
+  if (*buflen < info.length)
+  {
+    *buflen= info.length;
+    DBUG_RETURN(ENCRYPTION_KEY_BUFFER_TOO_SMALL);
+  }
+  *buflen= info.length;
+  memcpy(dstbuf, info.data, info.length);
+  DBUG_RETURN(0);
+}
+
+
+/* Plugin defs */
+struct st_mariadb_encryption aws_key_management_plugin= {
+  MariaDB_ENCRYPTION_INTERFACE_VERSION,
+  get_latest_key_version,
+  get_key,
+  // use default encrypt/decrypt functions
+  0, 0, 0, 0, 0
+};
+
+
+static TYPELIB key_spec_typelib =
+{
+  array_elements(key_spec_names) - 1, "",
+  key_spec_names, NULL
+};
+
+const char *log_level_names[] =
+{
+  "Off",
+  "Fatal",
+  "Error",
+  "Warn",
+  "Info",
+  "Debug",
+  "Trace",
+  0
+};
+
+static TYPELIB log_level_typelib =
+{
+  array_elements(log_level_names) - 1, "",
+  log_level_names, NULL
+};
+
+static MYSQL_SYSVAR_STR(master_key_id, master_key_id,
+  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_MEMALLOC,
+  "Key id for master encryption key. Used to create new datakeys. If not set, no new keys will be created",
+  NULL, NULL, "");
+
+static MYSQL_SYSVAR_ENUM(key_spec, key_spec,
+  PLUGIN_VAR_RQCMDARG,
+  "Encryption algorithm used to create new keys.",
+  NULL, NULL, 0, &key_spec_typelib);
+
+
+static MYSQL_SYSVAR_ENUM(log_level, log_level,
+  PLUGIN_VAR_RQCMDARG,
+  "Logging for AWS API",
+  NULL, NULL, 0, &log_level_typelib);
+
+
+static MYSQL_SYSVAR_INT(rotate_key, rotate_key,
+  PLUGIN_VAR_RQCMDARG,
+  "Set this variable to key id to perform rotation of the key. Specify -1 to rotate all keys",
+  NULL, update_rotate, 0, -1, INT_MAX, 1);
+
+static struct st_mysql_sys_var* settings[]= {
+  MYSQL_SYSVAR(master_key_id),
+  MYSQL_SYSVAR(key_spec),
+  MYSQL_SYSVAR(rotate_key),
+  MYSQL_SYSVAR(log_level),
+  NULL
+};
+
+/*
+  Plugin library descriptor
+*/
+maria_declare_plugin(aws_key_management)
+{
+  MariaDB_ENCRYPTION_PLUGIN,
+    &aws_key_management_plugin,
+    "aws_key_management",
+    "MariaDB Corporation",
+    "AWS key management plugin",
+    PLUGIN_LICENSE_GPL,
+    plugin_init,
+    plugin_deinit,
+    0x0100,
+    NULL,
+    settings,
+    "1.0",
+    MariaDB_PLUGIN_MATURITY_EXPERIMENTAL
+}
+maria_declare_plugin_end;