This commit (mainly for 32bit CPUs) is the first of a series of
similar commits to handle known integer overflows. Basically, all
of them are harmless, since they affect rendering of glyphs only,
not posing security threats. It is expected that fuzzying will show
up more overflows, to be fixed in due course.
The idea is to mark places where overflows can occur, using macros
that simply cast to unsigned integers, because overflow arithmetic
is well defined in this case. Doing so suppresses run-time errors
of sanitizers without adding computational overhead.
* include/freetype/internal/ftcalc.h (OVERFLOW_ADD_INT,
OVERFLOW_SUB_INT, OVERFLOW_MUL_INT, OVERFLOW_ADD_LONG,
OVERFLOW_SUB_LONG, OVERFLOW_MUL_LONG): New macros.
* src/base/ftcalc.c (FT_RoundFix, FT_CeilFix, FT_Matrix_Multiply,
FT_Matrix_Multiply_Scaled, FT_Vector_Transform_Scaled,
ft_corner_orientation): Use new macros.
* src/base/ftoutln.c (FT_Outline_Get_Orientation): Use new macros.
* src/base/ftcalc.c (FT_MOVE_SIGN): Add argument to pass unsigned
value, to be used as the result.
(FT_MulDiv, FT_MulDiv_No_Round, FT_DivFix, FT_MulFix,
FT_Vector_NormLen): Updated.
Extra bitmap padding for LCD filtering depends on the filter. The
default 5-tap filter needs 2 extra subpixels. The light 3-tap filter
needs only 1 extra subpixel. This space could be already available
due to rounding. In order to optimize the padding, we now expand
CBox for the given filter weights before rounding.
This change breakes current Skia (and Firefox).
* include/freetype/internal/ftobjs.h (FT_LibraryRec)
[FT_CONFIG_OPTION_SUBPIXEL_RENDERING]: Remove `lcd_extra' field.
* src/base/ftlcdfil.c (FT_Library_SetLcdFilterWeights,
FT_Library_SetLcdFilter): Remove `lcd_extra' initializations.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Implement dymanic
LCD padding.
Problem reported by Markus Trippelsdorf <markus@trippelsdorf.de> and
Nikolaus Waxweiler <madigens@gmail.com>.
* src/base/ftobjs.c (FT_Request_Size): Trigger recomputation of
auto-hinter metrics. Without this change, multiple size changing
calls for a single face fail.
This mode uses fractional advance widths and doesn't scale glyphs
horizontally, only applying vertical scaling and hinting.
At the same time, the behaviour of the `light' auto-hinter gets
restored for backwards compatibility: Both vertical and horizontal
scaling is again based on rounded metrics values (this was changed
in a commit from 2017-03-30 as a side effect). To be more precise,
the behaviour is restored for TrueType fonts only; for other font
formats like Type 1, this is a new feature of the `light' hinting
mode.
* include/freetype/freetype.h (FT_LOAD_TARGET_SLIGHT): New macro.
(FT_RENDER_MODE_SLIGHT): New render mode.
* include/freetype/internal/ftobjs.h (FT_Size_InternalRec): Add
`autohint_mode' and `autohint_metrics' fields.
* src/autofit/afcjk.c (af_cjk_hints_init), src/autofit/aflatin.c
(af_latin_hints_init), src/autofit/aflatin2 (af_latin2_hints_init):
Updated.
* src/autofit/afloader.c (af_loader_embolden_glyph_in_slot): Use
`autohint_metrics'.
(af_loader_load_glyph): s/internal/slot_internal/.
Initialize `autohint_metrics' and `autohint_mode' depending on
current auto-hint mode.
Use `autohint_metrics'.
Updated.
* src/base/ftadvanc.c (LOAD_ADVANCE_FAST_CHECK): Updated.
* src/base/ftobjs.c (FT_Load_Glyph): Updated.
(FT_New_Size): Allocate `internal' object.
* src/pshinter/pshalgo.c (ps_hints_apply): Updated.
* src/smooth/ftsmooth.c (ft_smooth_render): Updated.
We are going to extend this later on.
* include/freetype/internal/ftobjs.h (FT_Size_InternalRec): New
structure with a single field `module_data'.
* src/base/ftobjs.c (FT_New_Size): Allocate `internal' field of
`FT_Size' structure.
* src/cff/cffgload.c (cff_builder_init, cff_decoder_prepare): Use
`size->internal->module_data' instead of `size->internal'.
* src/cff/cffobjs.c (cff_size_done): Deallocate `module_data'.
(cff_size_init, cff_size_select, cff_size_request): Use
`size->internal->module_data' instead of `size->internal'.
* src/cif/cidobjs.c (cid_size_done, cid_size_init,
cid_size_request): Use `size->internal->module_data' instead of
`size->internal'.
* src/psaux/psobjs.c (t1_builder_ini): Use
`size->internal->module_data' instead of `size->internal'.
* src/type1/t1objs.c (T1_Size_Done, T1_Size_Init, T1_Size_Request):
Use `size->internal->module_data' instead of `size->internal'.
* src/base/ftmm.c (FT_Set_Var_Design_Coordinates,
FT_Set_MM_Blend_Coordinates, FT_Set_Var_Blend_Coordinates): Ignore
return value of `ft_face_get_mvar_service'; instead, check whether a
service is actually returned.
* src/base/ftsnames.c: Include FT_INTERNAL_DEBUG_H.
* src/cff/cffobjs.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
FT_MULTIPLE_MASTERS_H and FT_SERVICE_MULTIPLE_MASTERS_H.
* src/sfnt/sfdriver.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
FT_MULTIPLE_MASTERS_H and FT_SERVICE_MULTIPLE_MASTERS_H.
(get_win_string, get_apple_string): Initialize `result'.
This commit provides the framework, to be filled with something
useful in the next commits.
* include/freetype/freetype.h (FT_Face_Properties): Declare.
* src/base/ftobjs.c (FT_Face_Properties): New function.
* src/base/ftmm.c: Include FT_SERVICE_METRICS_VARIATIONS_H.
(ft_face_get_mvar_service): New auxiliary function to look up
metrics variation service.
(FT_Set_Var_Design_Coordinates, FT_Set_MM_Blend_Coordinates,
FT_Set_Var_Blend_Coordinates): Call metrics variation service.
* src/truetype/ttobjs.c (tt_face_init): Use metrics variations for
named instances.
Everything is guarded with TT_CONFIG_OPTION_GX_VAR_SUPPORT.
* src/base/ftadvanc.c (LOAD_ADVANCE_FAST_CHECK): Don't handle MM.
* src/cff/cffdrivr.c: Include FT_SERVICE_METRICS_VARIATIONS_H.
(cff_get_advances): Test for HVAR and VVAR.
* src/truetype/ttdriver.c (tt_get_advances): Test for HVAR and VVAR.
Reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=304
* src/base/ftobjs.c (FT_Open_Face): Code moved to...
(ft_open_face_internal): ... this function.
Add a parameter to control whether we try special Mac font handling
in case of failure.
(FT_Open_Face, FT_New_Face, FT_New_Memory_Face,
open_face_from_buffer): Use `ft_open_face_internal'.
* src/base/ftobjs.c (FT_Open_Face): Return info on number of
available faces and numbered instances, or the indices of the
requested face and numbered instance.
* src/sfnt/sfobjs. (sfnt_open_font): Trace number of subfonts.
It can now differentiate between local and global searches.
* src/base/ftobjs.c (ft_module_get_service): Add `global' argument.
(FT_Get_TrueType_Engine_Type): Updated.
* src/cff/cffdrivr.c (cff_get_ps_name, cff_get_cmap_info): Updated.
* include/freetype/internal/ftobjs.h: Updated.
* include/freetype/internal/ftserv.h (FT_FACE_FIND_GLOBAL_SERVICE):
Updated.
Note that the low-level functions aren't implemented yet.
* include/freetype/ftmm.h: Declare.
* include/freetype/internal/services/svmm.h
(FT_Get_Var_Design_Func): New typedef.
(MultiMasters): New MM service function `get_var_design'.
(FT_DEFINE_SERVICE_MULTIMASTERSREC): Updated.
Update all callers.
* src/base/ftmm.c (FT_Get_Var_Design_Coordinates): Implement.
* src/truetype/ttdriver.c: Updated.
* src/truetype/ttgxvar.c (TT_Get_Var_Design): New dummy function to
handle `get_var_design' service.
* src/truetype/ttgxvar.h: Updated.
* src/type1/t1driver.c: Updated.
* src/type1/t1load.c (T1_Get_Var_Design): New dummp function to
handle `get_var_design' service.
* src/type1/t1load.h: Updated.
Alexei Podtelezhnikov