diff options
| -rw-r--r-- | Changelog-Trunk.txt | 2 | ||||
| -rw-r--r-- | src/map/clif.c | 32 |
2 files changed, 32 insertions, 2 deletions
diff --git a/Changelog-Trunk.txt b/Changelog-Trunk.txt index 193e28b0c..552652cf9 100644 --- a/Changelog-Trunk.txt +++ b/Changelog-Trunk.txt @@ -1,5 +1,7 @@ Date Added +2011/08/20 + * Added quick validation of guild emblems' bitmap format to prevent forged emblems, that cause the client to crash, from being accepted (thx to sinya for a sample). [Ai4rei] 2011/08/16 * Added -fno-strict-aliasing detection to configure.in (-fstrict-aliasing is added through -O2), since the code is not aliasing safe and causes warnings with gcc. [Ai4rei] - This also fixes a missing line in the pre-built configure script (since r14870). diff --git a/src/map/clif.c b/src/map/clif.c index 5ee32c3e1..d45c941ba 100644 --- a/src/map/clif.c +++ b/src/map/clif.c @@ -4,6 +4,7 @@ #include "../common/cbasetypes.h" #include "../common/socket.h" #include "../common/timer.h" +#include "../common/grfio.h" #include "../common/malloc.h" #include "../common/version.h" #include "../common/nullpo.h" @@ -11087,16 +11088,43 @@ void clif_parse_GuildRequestEmblem(int fd,struct map_session_data *sd) clif_guild_emblem(sd,g); } + +/// Validates data of a guild emblem (compressed bitmap) +static bool clif_validate_emblem(const uint8* emblem, unsigned long emblem_len) +{ + bool success; + uint8 buf[1800]; // no well-formed emblem bitmap is larger than 1782 (24 bit) / 1654 (8 bit) bytes + unsigned long buf_len = sizeof(buf); + + success = ( decode_zip(buf, &buf_len, emblem, emblem_len) == 0 && buf_len >= 18 ) // sizeof(BITMAPFILEHEADER) + sizeof(biSize) of the following info header struct + && RBUFW(buf,0) == 0x4d42 // BITMAPFILEHEADER.bfType (signature) + && RBUFL(buf,2) == buf_len // BITMAPFILEHEADER.bfSize (file size) + && RBUFL(buf,10) < buf_len // BITMAPFILEHEADER.bfOffBits (offset to bitmap bits) + ; + + return success; +} + + /*========================================== * ギルドエンブレム変更 * S 0153 <packet len>.W <emblem data>.?B *------------------------------------------*/ void clif_parse_GuildChangeEmblem(int fd,struct map_session_data *sd) { - if(!sd->state.gmaster_flag) + unsigned long emblem_len = RFIFOW(fd,2)-4; + const uint8* emblem = RFIFOP(fd,4); + + if( !emblem_len || !sd->state.gmaster_flag ) + return; + + if( !clif_validate_emblem(emblem, emblem_len) ) + { + ShowWarning("clif_parse_GuildChangeEmblem: Rejected malformed guild emblem (size=%lu, accound_id=%d, char_id=%d, guild_id=%d).\n", emblem_len, sd->status.account_id, sd->status.char_id, sd->status.guild_id); return; + } - guild_change_emblem(sd,RFIFOW(fd,2)-4,(char*)RFIFOP(fd,4)); + guild_change_emblem(sd, emblem_len, emblem); } /*========================================== |