diff options
Diffstat (limited to 'sql/mf_iocache_encr.cc')
-rw-r--r-- | sql/mf_iocache_encr.cc | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/sql/mf_iocache_encr.cc b/sql/mf_iocache_encr.cc new file mode 100644 index 00000000..63830ec6 --- /dev/null +++ b/sql/mf_iocache_encr.cc @@ -0,0 +1,275 @@ +/* + Copyright (c) 2015, 2020, MariaDB + + 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 02110-1335 USA */ + +/************************************************************************* + Limitation of encrypted IO_CACHEs + 1. Designed to support temporary files only (open_cached_file, fd=-1) + 2. Created with WRITE_CACHE, later can be reinit_io_cache'ed to + READ_CACHE and WRITE_CACHE in any order arbitrary number of times. + 3. no seeks for writes, but reinit_io_cache(WRITE_CACHE, seek_offset) + is allowed (there's a special hack in reinit_io_cache() for that) +*/ + +#include "../mysys/mysys_priv.h" +#include "log.h" +#include "mysqld.h" +#include "sql_class.h" + +static uint keyid, keyver; + +#define set_iv(IV, N1, N2) \ + do { \ + compile_time_assert(sizeof(IV) >= sizeof(N1) + sizeof(N2)); \ + memcpy(IV, &(N1), sizeof(N1)); \ + memcpy(IV + sizeof(N1), &(N2), sizeof(N2)); \ + } while(0) + +static int my_b_encr_read(IO_CACHE *info, uchar *Buffer, size_t Count) +{ + my_off_t pos_in_file= info->pos_in_file + (info->read_end - info->buffer); + my_off_t old_pos_in_file= pos_in_file, pos_offset= 0; + IO_CACHE_CRYPT *crypt_data= + (IO_CACHE_CRYPT *)(info->buffer + info->buffer_length + MY_AES_BLOCK_SIZE); + uchar *wbuffer= (uchar*)&(crypt_data->inbuf_counter); + uchar *ebuffer= (uchar*)(crypt_data + 1); + DBUG_ENTER("my_b_encr_read"); + + if (pos_in_file == info->end_of_file) + { + /* reading past EOF should not empty the cache */ + info->read_pos= info->read_end; + info->error= 0; + DBUG_RETURN(MY_TEST(Count)); + } + + if (info->seek_not_done) + { + my_off_t wpos; + + pos_offset= pos_in_file % info->buffer_length; + pos_in_file-= pos_offset; + + wpos= pos_in_file / info->buffer_length * crypt_data->block_length; + + if ((mysql_file_seek(info->file, wpos, MY_SEEK_SET, MYF(0)) + == MY_FILEPOS_ERROR)) + { + info->error= -1; + DBUG_RETURN(1); + } + info->seek_not_done= 0; + if (info->next_file_user) + { + IO_CACHE *c; + for (c= info->next_file_user; + c!= info; + c= c->next_file_user) + { + c->seek_not_done= 1; + } + } + } + + do + { + uint elength, wlength, length; + uchar iv[MY_AES_BLOCK_SIZE]= {0}; + + DBUG_ASSERT(pos_in_file % info->buffer_length == 0); + + if (info->end_of_file - pos_in_file >= info->buffer_length) + wlength= crypt_data->block_length; + else + wlength= crypt_data->last_block_length; + + if (mysql_file_read(info->file, wbuffer, wlength, info->myflags | MY_NABP)) + { + info->error= -1; + DBUG_RETURN(1); + } + + elength= wlength - (uint)(ebuffer - wbuffer); + set_iv(iv, pos_in_file, crypt_data->inbuf_counter); + + if (encryption_crypt(ebuffer, elength, info->buffer, &length, + crypt_data->key, sizeof(crypt_data->key), + iv, sizeof(iv), ENCRYPTION_FLAG_DECRYPT, + keyid, keyver)) + { + my_errno= 1; + DBUG_RETURN(info->error= -1); + } + + DBUG_ASSERT(length <= info->buffer_length); + + size_t copied= MY_MIN(Count, (size_t)(length - pos_offset)); + if (copied) + { + memcpy(Buffer, info->buffer + pos_offset, copied); + Count-= copied; + Buffer+= copied; + } + + info->read_pos= info->buffer + pos_offset + copied; + info->read_end= info->buffer + length; + info->pos_in_file= pos_in_file; + pos_in_file+= length; + pos_offset= 0; + + if (wlength < crypt_data->block_length && pos_in_file < info->end_of_file) + { + info->error= (int)(pos_in_file - old_pos_in_file); + DBUG_RETURN(1); + } + } while (Count); + + DBUG_RETURN(0); +} + +static int my_b_encr_write(IO_CACHE *info, const uchar *Buffer, size_t Count) +{ + IO_CACHE_CRYPT *crypt_data= + (IO_CACHE_CRYPT *)(info->buffer + info->buffer_length + MY_AES_BLOCK_SIZE); + uchar *wbuffer= (uchar*)&(crypt_data->inbuf_counter); + uchar *ebuffer= (uchar*)(crypt_data + 1); + DBUG_ENTER("my_b_encr_write"); + + if (Buffer != info->write_buffer) + { + Count-= Count % info->buffer_length; + if (!Count) + DBUG_RETURN(0); + } + + if (info->seek_not_done) + { + DBUG_ASSERT(info->pos_in_file % info->buffer_length == 0); + my_off_t wpos= info->pos_in_file / info->buffer_length * crypt_data->block_length; + + if ((mysql_file_seek(info->file, wpos, MY_SEEK_SET, MYF(0)) == MY_FILEPOS_ERROR)) + { + info->error= -1; + DBUG_RETURN(1); + } + info->seek_not_done= 0; + } + + if (info->pos_in_file == 0) + { + if (my_random_bytes(crypt_data->key, sizeof(crypt_data->key))) + { + my_errno= 1; + DBUG_RETURN(info->error= -1); + } + crypt_data->counter= 0; + + IF_DBUG(crypt_data->block_length= 0,); + } + + do + { + size_t length= MY_MIN(info->buffer_length, Count); + uint elength, wlength; + uchar iv[MY_AES_BLOCK_SIZE]= {0}; + + crypt_data->inbuf_counter= crypt_data->counter; + set_iv(iv, info->pos_in_file, crypt_data->inbuf_counter); + + if (encryption_crypt(Buffer, (uint)length, ebuffer, &elength, + crypt_data->key, (uint) sizeof(crypt_data->key), + iv, (uint) sizeof(iv), ENCRYPTION_FLAG_ENCRYPT, + keyid, keyver)) + { + my_errno= 1; + DBUG_RETURN(info->error= -1); + } + wlength= elength + (uint)(ebuffer - wbuffer); + + if (length == info->buffer_length) + { + /* + block_length should be always the same. that is, encrypting + buffer_length bytes should *always* produce block_length bytes + */ + DBUG_ASSERT(crypt_data->block_length == 0 || crypt_data->block_length == wlength); + DBUG_ASSERT(elength <= encryption_encrypted_length((uint)length, keyid, keyver)); + crypt_data->block_length= wlength; + } + else + { + /* if we write a partial block, it *must* be the last write */ + IF_DBUG(info->write_function= 0,); + crypt_data->last_block_length= wlength; + } + + if (mysql_file_write(info->file, wbuffer, wlength, info->myflags | MY_NABP)) + DBUG_RETURN(info->error= -1); + + Buffer+= length; + Count-= length; + info->pos_in_file+= length; + crypt_data->counter++; + } while (Count); + DBUG_RETURN(0); +} + +/** + determine what key id and key version to use for IO_CACHE temp files + + First, try key id 2, if it doesn't exist, use key id 1. + + (key id 1 is the default system key id, used pretty much everywhere, it must + exist. key id 2 is for tempfiles, it can be used, for example, to set a + faster encryption algorithm for temporary files) + + This looks like it might have a bug: if an encryption plugin is unloaded when + there's an open IO_CACHE, that IO_CACHE will become unreadable after reinit. + But in fact it is safe, as an encryption plugin can only be unloaded on + server shutdown. + + Note that encrypt_tmp_files variable is read-only. +*/ +int init_io_cache_encryption() +{ + if (encrypt_tmp_files) + { + keyid= ENCRYPTION_KEY_TEMPORARY_DATA; + keyver= encryption_key_get_latest_version(keyid); + if (keyver == ENCRYPTION_KEY_VERSION_INVALID) + { + keyid= ENCRYPTION_KEY_SYSTEM_DATA; + keyver= encryption_key_get_latest_version(keyid); + } + if (keyver == ENCRYPTION_KEY_VERSION_INVALID) + { + sql_print_error("Failed to enable encryption of temporary files"); + return 1; + } + + if (keyver != ENCRYPTION_KEY_NOT_ENCRYPTED) + { + sql_print_information("Using encryption key id %d for temporary files", keyid); + _my_b_encr_read= my_b_encr_read; + _my_b_encr_write= my_b_encr_write; + return 0; + } + } + + _my_b_encr_read= 0; + _my_b_encr_write= 0; + return 0; +} + |