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authorwolfbeast <mcwerewolf@wolfbeast.com>2019-11-14 10:07:01 +0100
committerwolfbeast <mcwerewolf@wolfbeast.com>2019-11-14 10:07:01 +0100
commit0f8691a48869932cd3de5195f5211c25e4691b21 (patch)
tree829675d64c457be0b447dfbcf9534cc22f83d392 /gfx/ots/src/layout.cc
parent36975f3865948f3faa959fe386e58b22783bd379 (diff)
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Issue #1288 - Part 4: Update the OpenType Sanitizer component to 8.0.0
Diffstat (limited to 'gfx/ots/src/layout.cc')
-rw-r--r--gfx/ots/src/layout.cc249
1 files changed, 202 insertions, 47 deletions
diff --git a/gfx/ots/src/layout.cc b/gfx/ots/src/layout.cc
index 1d87b53d4..8e99f573d 100644
--- a/gfx/ots/src/layout.cc
+++ b/gfx/ots/src/layout.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011-2017 The OTS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
@@ -7,6 +7,7 @@
#include <limits>
#include <vector>
+#include "fvar.h"
#include "gdef.h"
// OpenType Layout Common Table Formats
@@ -22,14 +23,11 @@ const uint32_t kScriptTableTagDflt = 0x44464c54;
const uint16_t kNoRequiredFeatureIndexDefined = 0xFFFF;
// The lookup flag bit which indicates existence of MarkFilteringSet.
const uint16_t kUseMarkFilteringSetBit = 0x0010;
-// The lookup flags which require GDEF table.
-const uint16_t kGdefRequiredFlags = 0x0002 | 0x0004 | 0x0008;
-// The mask for MarkAttachmentType.
-const uint16_t kMarkAttachmentTypeMask = 0xFF00;
// The maximum type number of format for device tables.
const uint16_t kMaxDeltaFormatType = 3;
-// The maximum number of class value.
-const uint16_t kMaxClassDefValue = 0xFFFF;
+// In variation fonts, Device Tables are replaced by VariationIndex tables,
+// indicated by this flag in the deltaFormat field.
+const uint16_t kVariationIndex = 0x8000;
struct ScriptRecord {
uint32_t tag;
@@ -94,15 +92,12 @@ bool ParseScriptTable(const ots::Font *font,
}
// The spec requires a script table for 'DFLT' tag must contain non-NULL
- // |offset_default_lang_sys| and |lang_sys_count| == 0
+ // |offset_default_lang_sys|.
// https://www.microsoft.com/typography/otspec/chapter2.htm
if (tag == kScriptTableTagDflt) {
if (offset_default_lang_sys == 0) {
return OTS_FAILURE_MSG("DFLT script doesn't satisfy the spec. DefaultLangSys is NULL");
}
- if (lang_sys_count != 0) {
- return OTS_FAILURE_MSG("DFLT script doesn't satisfy the spec. LangSysCount is not zero: %d", lang_sys_count);
- }
}
const unsigned lang_sys_record_end =
@@ -197,27 +192,7 @@ bool ParseLookupTable(ots::Font *font, const uint8_t *data,
return OTS_FAILURE_MSG("Bad lookup type %d", lookup_type);
}
- // Check lookup flags.
- if ((lookup_flag & kGdefRequiredFlags) &&
- (!font->gdef || !font->gdef->has_glyph_class_def)) {
- return OTS_FAILURE_MSG("Lookup flags require GDEF table, "
- "but none was found: %d", lookup_flag);
- }
- if ((lookup_flag & kMarkAttachmentTypeMask) &&
- (!font->gdef || !font->gdef->has_mark_attachment_class_def)) {
- return OTS_FAILURE_MSG("Lookup flags ask for mark attachment, "
- "but there is no GDEF table or it has no "
- "mark attachment classes: %d", lookup_flag);
- }
- bool use_mark_filtering_set = false;
- if (lookup_flag & kUseMarkFilteringSetBit) {
- if (!font->gdef || !font->gdef->has_mark_glyph_sets_def) {
- return OTS_FAILURE_MSG("Lookup flags ask for mark filtering, "
- "but there is no GDEF table or it has no "
- "mark filtering sets: %d", lookup_flag);
- }
- use_mark_filtering_set = true;
- }
+ bool use_mark_filtering_set = lookup_flag & kUseMarkFilteringSetBit;
std::vector<uint16_t> subtables;
subtables.reserve(subtable_count);
@@ -248,8 +223,12 @@ bool ParseLookupTable(ots::Font *font, const uint8_t *data,
if (!subtable.ReadU16(&mark_filtering_set)) {
return OTS_FAILURE_MSG("Failed to read mark filtering set");
}
- if (font->gdef->num_mark_glyph_sets == 0 ||
- mark_filtering_set >= font->gdef->num_mark_glyph_sets) {
+
+ ots::OpenTypeGDEF *gdef = static_cast<ots::OpenTypeGDEF*>(
+ font->GetTypedTable(OTS_TAG_GDEF));
+
+ if (gdef && (gdef->num_mark_glyph_sets == 0 ||
+ mark_filtering_set >= gdef->num_mark_glyph_sets)) {
return OTS_FAILURE_MSG("Bad mark filtering set %d", mark_filtering_set);
}
}
@@ -311,15 +290,15 @@ bool ParseClassDefFormat2(const ots::Font *font,
// Skip format field.
if (!subtable.Skip(2)) {
- return OTS_FAILURE_MSG("Failed to skip format of class defintion header");
+ return OTS_FAILURE_MSG("Failed to read class definition format");
}
uint16_t range_count = 0;
if (!subtable.ReadU16(&range_count)) {
- return OTS_FAILURE_MSG("Failed to read range count in class definition");
+ return OTS_FAILURE_MSG("Failed to read classRangeCount");
}
if (range_count > num_glyphs) {
- return OTS_FAILURE_MSG("bad range count: %u", range_count);
+ return OTS_FAILURE_MSG("classRangeCount > glyph count: %u > %u", range_count, num_glyphs);
}
uint16_t last_end = 0;
@@ -330,13 +309,16 @@ bool ParseClassDefFormat2(const ots::Font *font,
if (!subtable.ReadU16(&start) ||
!subtable.ReadU16(&end) ||
!subtable.ReadU16(&class_value)) {
- return OTS_FAILURE_MSG("Failed to read class definition reange %d", i);
+ return OTS_FAILURE_MSG("Failed to read ClassRangeRecord %d", i);
+ }
+ if (start > end) {
+ return OTS_FAILURE_MSG("ClassRangeRecord %d, start > end: %u > %u", i, start, end);
}
- if (start > end || (last_end && start <= last_end)) {
- return OTS_FAILURE_MSG("glyph range is overlapping.in range %d", i);
+ if (last_end && start <= last_end) {
+ return OTS_FAILURE_MSG("ClassRangeRecord %d start overlaps with end of the previous one: %u <= %u", i, start, last_end);
}
if (class_value > num_classes) {
- return OTS_FAILURE_MSG("bad class value: %u", class_value);
+ return OTS_FAILURE_MSG("ClassRangeRecord %d class > number of classes: %u > %u", i, class_value, num_classes);
}
last_end = end;
}
@@ -661,7 +643,7 @@ bool ParseContextFormat2(const ots::Font *font,
}
if (!ots::ParseClassDefTable(font, data + offset_class_def,
length - offset_class_def,
- num_glyphs, kMaxClassDefValue)) {
+ num_glyphs, ots::kMaxClassDefValue)) {
return OTS_FAILURE_MSG("Failed to parse class definition table in context format 2");
}
@@ -1014,7 +996,7 @@ bool ParseChainContextFormat2(const ots::Font *font,
}
if (!ots::ParseClassDefTable(font, data + offset_backtrack_class_def,
length - offset_backtrack_class_def,
- num_glyphs, kMaxClassDefValue)) {
+ num_glyphs, ots::kMaxClassDefValue)) {
return OTS_FAILURE_MSG("Failed to parse backtrack class defn table in chain context format 2");
}
}
@@ -1025,7 +1007,7 @@ bool ParseChainContextFormat2(const ots::Font *font,
}
if (!ots::ParseClassDefTable(font, data + offset_input_class_def,
length - offset_input_class_def,
- num_glyphs, kMaxClassDefValue)) {
+ num_glyphs, ots::kMaxClassDefValue)) {
return OTS_FAILURE_MSG("Failed to parse input class defn in chain context format 2");
}
@@ -1036,7 +1018,7 @@ bool ParseChainContextFormat2(const ots::Font *font,
}
if (!ots::ParseClassDefTable(font, data + offset_lookahead_class_def,
length - offset_lookahead_class_def,
- num_glyphs, kMaxClassDefValue)) {
+ num_glyphs, ots::kMaxClassDefValue)) {
return OTS_FAILURE_MSG("Failed to parse lookahead class defn in chain context format 2");
}
}
@@ -1400,11 +1382,17 @@ bool ParseDeviceTable(const ots::Font *font,
!subtable.ReadU16(&delta_format)) {
return OTS_FAILURE_MSG("Failed to read device table header");
}
+ if (delta_format == kVariationIndex) {
+ // start_size and end_size are replaced by deltaSetOuterIndex
+ // and deltaSetInnerIndex respectively, but we don't attempt to
+ // check them here, so nothing more to do.
+ return true;
+ }
if (start_size > end_size) {
- return OTS_FAILURE_MSG("bad size range: %u > %u", start_size, end_size);
+ return OTS_FAILURE_MSG("Bad device table size range: %u > %u", start_size, end_size);
}
if (delta_format == 0 || delta_format > kMaxDeltaFormatType) {
- return OTS_FAILURE_MSG("bad delta format: %u", delta_format);
+ return OTS_FAILURE_MSG("Bad device table delta format: 0x%x", delta_format);
}
// The number of delta values per uint16. The device table should contain
// at least |num_units| * 2 bytes compressed data.
@@ -1516,6 +1504,173 @@ bool ParseExtensionSubtable(const Font *font,
return true;
}
+bool ParseConditionTable(const Font *font,
+ const uint8_t *data, const size_t length,
+ const uint16_t axis_count) {
+ Buffer subtable(data, length);
+
+ uint16_t format = 0;
+ if (!subtable.ReadU16(&format)) {
+ return OTS_FAILURE_MSG("Failed to read condition table format");
+ }
+
+ if (format != 1) {
+ // An unknown format is not an error, but should be ignored per spec.
+ return true;
+ }
+
+ uint16_t axis_index = 0;
+ int16_t filter_range_min_value = 0;
+ int16_t filter_range_max_value = 0;
+ if (!subtable.ReadU16(&axis_index) ||
+ !subtable.ReadS16(&filter_range_min_value) ||
+ !subtable.ReadS16(&filter_range_max_value)) {
+ return OTS_FAILURE_MSG("Failed to read condition table (format 1)");
+ }
+
+ if (axis_index >= axis_count) {
+ return OTS_FAILURE_MSG("Axis index out of range in condition");
+ }
+
+ // Check min/max values are within range -1.0 .. 1.0 and properly ordered
+ if (filter_range_min_value < -0x4000 || // -1.0 in F2DOT14 format
+ filter_range_max_value > 0x4000 || // +1.0 in F2DOT14 format
+ filter_range_min_value > filter_range_max_value) {
+ return OTS_FAILURE_MSG("Invalid filter range in condition");
+ }
+
+ return true;
+}
+
+bool ParseConditionSetTable(const Font *font,
+ const uint8_t *data, const size_t length,
+ const uint16_t axis_count) {
+ Buffer subtable(data, length);
+
+ uint16_t condition_count = 0;
+ if (!subtable.ReadU16(&condition_count)) {
+ return OTS_FAILURE_MSG("Failed to read condition count");
+ }
+
+ for (uint16_t i = 0; i < condition_count; i++) {
+ uint32_t condition_offset = 0;
+ if (!subtable.ReadU32(&condition_offset)) {
+ return OTS_FAILURE_MSG("Failed to read condition offset");
+ }
+ if (condition_offset < subtable.offset() || condition_offset >= length) {
+ return OTS_FAILURE_MSG("Offset out of range");
+ }
+ if (!ParseConditionTable(font, data + condition_offset, length - condition_offset,
+ axis_count)) {
+ return OTS_FAILURE_MSG("Failed to parse condition table");
+ }
+ }
+
+ return true;
+}
+
+bool ParseFeatureTableSubstitutionTable(const Font *font,
+ const uint8_t *data, const size_t length,
+ const uint16_t num_lookups) {
+ Buffer subtable(data, length);
+
+ uint16_t version_major = 0;
+ uint16_t version_minor = 0;
+ uint16_t substitution_count = 0;
+ const size_t kFeatureTableSubstitutionHeaderSize = 3 * sizeof(uint16_t);
+
+ if (!subtable.ReadU16(&version_major) ||
+ !subtable.ReadU16(&version_minor) ||
+ !subtable.ReadU16(&substitution_count)) {
+ return OTS_FAILURE_MSG("Failed to read feature table substitution table header");
+ }
+
+ for (uint16_t i = 0; i < substitution_count; i++) {
+ uint16_t feature_index = 0;
+ uint32_t alternate_feature_table_offset = 0;
+ const size_t kFeatureTableSubstitutionRecordSize = sizeof(uint16_t) + sizeof(uint32_t);
+
+ if (!subtable.ReadU16(&feature_index) ||
+ !subtable.ReadU32(&alternate_feature_table_offset)) {
+ return OTS_FAILURE_MSG("Failed to read feature table substitution record");
+ }
+
+ if (alternate_feature_table_offset < kFeatureTableSubstitutionHeaderSize +
+ kFeatureTableSubstitutionRecordSize * substitution_count ||
+ alternate_feature_table_offset >= length) {
+ return OTS_FAILURE_MSG("Invalid alternate feature table offset");
+ }
+
+ if (!ParseFeatureTable(font, data + alternate_feature_table_offset,
+ length - alternate_feature_table_offset, num_lookups)) {
+ return OTS_FAILURE_MSG("Failed to parse alternate feature table");
+ }
+ }
+
+ return true;
+}
+
+bool ParseFeatureVariationsTable(const Font *font,
+ const uint8_t *data, const size_t length,
+ const uint16_t num_lookups) {
+ Buffer subtable(data, length);
+
+ uint16_t version_major = 0;
+ uint16_t version_minor = 0;
+ uint32_t feature_variation_record_count = 0;
+
+ if (!subtable.ReadU16(&version_major) ||
+ !subtable.ReadU16(&version_minor) ||
+ !subtable.ReadU32(&feature_variation_record_count)) {
+ return OTS_FAILURE_MSG("Failed to read feature variations table header");
+ }
+
+ OpenTypeFVAR* fvar = static_cast<OpenTypeFVAR*>(font->GetTypedTable(OTS_TAG_FVAR));
+ if (!fvar) {
+ return OTS_FAILURE_MSG("Not a variation font");
+ }
+ const uint16_t axis_count = fvar->AxisCount();
+
+ const size_t kEndOfFeatureVariationRecords =
+ 2 * sizeof(uint16_t) + sizeof(uint32_t) +
+ feature_variation_record_count * 2 * sizeof(uint32_t);
+
+ for (uint32_t i = 0; i < feature_variation_record_count; i++) {
+ uint32_t condition_set_offset = 0;
+ uint32_t feature_table_substitution_offset = 0;
+ if (!subtable.ReadU32(&condition_set_offset) ||
+ !subtable.ReadU32(&feature_table_substitution_offset)) {
+ return OTS_FAILURE_MSG("Failed to read feature variation record");
+ }
+
+ if (condition_set_offset) {
+ if (condition_set_offset < kEndOfFeatureVariationRecords ||
+ condition_set_offset >= length) {
+ return OTS_FAILURE_MSG("Condition set offset out of range");
+ }
+ if (!ParseConditionSetTable(font, data + condition_set_offset,
+ length - condition_set_offset,
+ axis_count)) {
+ return OTS_FAILURE_MSG("Failed to parse condition set table");
+ }
+ }
+
+ if (feature_table_substitution_offset) {
+ if (feature_table_substitution_offset < kEndOfFeatureVariationRecords ||
+ feature_table_substitution_offset >= length) {
+ return OTS_FAILURE_MSG("Feature table substitution offset out of range");
+ }
+ if (!ParseFeatureTableSubstitutionTable(font, data + feature_table_substitution_offset,
+ length - feature_table_substitution_offset,
+ num_lookups)) {
+ return OTS_FAILURE_MSG("Failed to parse feature table substitution table");
+ }
+ }
+ }
+
+ return true;
+}
+
} // namespace ots
#undef TABLE_NAME