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Unified Diff: third_party/ots/src/woff2.cc

Issue 775893002: Updating OTS repo from https://github.com/khaledhosny/ots.git (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Updating with 4800 warning fix Created 6 years ago
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Index: third_party/ots/src/woff2.cc
diff --git a/third_party/ots/src/woff2.cc b/third_party/ots/src/woff2.cc
new file mode 100644
index 0000000000000000000000000000000000000000..31b562d90fb30aa1d93d465f9176a1f8121d3b19
--- /dev/null
+++ b/third_party/ots/src/woff2.cc
@@ -0,0 +1,991 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This is the implementation of decompression of the proposed WOFF Ultra
+// Condensed file format.
+
+#include <cassert>
+#include <cstdlib>
+#include <vector>
+
+#include "third_party/brotli/src/brotli/dec/decode.h"
+
+#include "opentype-sanitiser.h"
+#include "ots-memory-stream.h"
+#include "ots.h"
+#include "woff2.h"
+
+#define TABLE_NAME "WOFF2"
+
+namespace {
+
+// simple glyph flags
+const uint8_t kGlyfOnCurve = 1 << 0;
+const uint8_t kGlyfXShort = 1 << 1;
+const uint8_t kGlyfYShort = 1 << 2;
+const uint8_t kGlyfRepeat = 1 << 3;
+const uint8_t kGlyfThisXIsSame = 1 << 4;
+const uint8_t kGlyfThisYIsSame = 1 << 5;
+
+// composite glyph flags
+const int FLAG_ARG_1_AND_2_ARE_WORDS = 1 << 0;
+const int FLAG_WE_HAVE_A_SCALE = 1 << 3;
+const int FLAG_MORE_COMPONENTS = 1 << 5;
+const int FLAG_WE_HAVE_AN_X_AND_Y_SCALE = 1 << 6;
+const int FLAG_WE_HAVE_A_TWO_BY_TWO = 1 << 7;
+const int FLAG_WE_HAVE_INSTRUCTIONS = 1 << 8;
+
+const size_t kSfntHeaderSize = 12;
+const size_t kSfntEntrySize = 16;
+const size_t kCheckSumAdjustmentOffset = 8;
+
+const size_t kEndPtsOfContoursOffset = 10;
+const size_t kCompositeGlyphBegin = 10;
+
+// Note that the byte order is big-endian, not the same as ots.cc
+#define TAG(a, b, c, d) ((a << 24) | (b << 16) | (c << 8) | d)
+
+const unsigned int kWoff2FlagsTransform = 1 << 5;
+
+const uint32_t kKnownTags[] = {
+ TAG('c', 'm', 'a', 'p'), // 0
+ TAG('h', 'e', 'a', 'd'), // 1
+ TAG('h', 'h', 'e', 'a'), // 2
+ TAG('h', 'm', 't', 'x'), // 3
+ TAG('m', 'a', 'x', 'p'), // 4
+ TAG('n', 'a', 'm', 'e'), // 5
+ TAG('O', 'S', '/', '2'), // 6
+ TAG('p', 'o', 's', 't'), // 7
+ TAG('c', 'v', 't', ' '), // 8
+ TAG('f', 'p', 'g', 'm'), // 9
+ TAG('g', 'l', 'y', 'f'), // 10
+ TAG('l', 'o', 'c', 'a'), // 11
+ TAG('p', 'r', 'e', 'p'), // 12
+ TAG('C', 'F', 'F', ' '), // 13
+ TAG('V', 'O', 'R', 'G'), // 14
+ TAG('E', 'B', 'D', 'T'), // 15
+ TAG('E', 'B', 'L', 'C'), // 16
+ TAG('g', 'a', 's', 'p'), // 17
+ TAG('h', 'd', 'm', 'x'), // 18
+ TAG('k', 'e', 'r', 'n'), // 19
+ TAG('L', 'T', 'S', 'H'), // 20
+ TAG('P', 'C', 'L', 'T'), // 21
+ TAG('V', 'D', 'M', 'X'), // 22
+ TAG('v', 'h', 'e', 'a'), // 23
+ TAG('v', 'm', 't', 'x'), // 24
+ TAG('B', 'A', 'S', 'E'), // 25
+ TAG('G', 'D', 'E', 'F'), // 26
+ TAG('G', 'P', 'O', 'S'), // 27
+ TAG('G', 'S', 'U', 'B'), // 28
+ TAG('E', 'B', 'S', 'C'), // 29
+ TAG('J', 'S', 'T', 'F'), // 30
+ TAG('M', 'A', 'T', 'H'), // 31
+ TAG('C', 'B', 'D', 'T'), // 32
+ TAG('C', 'B', 'L', 'C'), // 33
+ TAG('C', 'O', 'L', 'R'), // 34
+ TAG('C', 'P', 'A', 'L'), // 35
+ TAG('S', 'V', 'G', ' '), // 36
+ TAG('s', 'b', 'i', 'x'), // 37
+ TAG('a', 'c', 'n', 't'), // 38
+ TAG('a', 'v', 'a', 'r'), // 39
+ TAG('b', 'd', 'a', 't'), // 40
+ TAG('b', 'l', 'o', 'c'), // 41
+ TAG('b', 's', 'l', 'n'), // 42
+ TAG('c', 'v', 'a', 'r'), // 43
+ TAG('f', 'd', 's', 'c'), // 44
+ TAG('f', 'e', 'a', 't'), // 45
+ TAG('f', 'm', 't', 'x'), // 46
+ TAG('f', 'v', 'a', 'r'), // 47
+ TAG('g', 'v', 'a', 'r'), // 48
+ TAG('h', 's', 't', 'y'), // 49
+ TAG('j', 'u', 's', 't'), // 50
+ TAG('l', 'c', 'a', 'r'), // 51
+ TAG('m', 'o', 'r', 't'), // 52
+ TAG('m', 'o', 'r', 'x'), // 53
+ TAG('o', 'p', 'b', 'd'), // 54
+ TAG('p', 'r', 'o', 'p'), // 55
+ TAG('t', 'r', 'a', 'k'), // 56
+ TAG('Z', 'a', 'p', 'f'), // 57
+ TAG('S', 'i', 'l', 'f'), // 58
+ TAG('G', 'l', 'a', 't'), // 59
+ TAG('G', 'l', 'o', 'c'), // 60
+ TAG('F', 'e', 'a', 't'), // 61
+ TAG('S', 'i', 'l', 'l'), // 62
+};
+
+struct Point {
+ int16_t x;
+ int16_t y;
+ bool on_curve;
+};
+
+struct Table {
+ uint32_t tag;
+ uint32_t flags;
+
+ uint32_t transform_length;
+
+ uint32_t dst_offset;
+ uint32_t dst_length;
+
+ Table()
+ : tag(0),
+ flags(0),
+ transform_length(0),
+ dst_offset(0),
+ dst_length(0) {}
+};
+
+// Based on section 6.1.1 of MicroType Express draft spec
+bool Read255UShort(ots::Buffer* buf, uint16_t* value) {
+ static const uint8_t kWordCode = 253;
+ static const uint8_t kOneMoreByteCode2 = 254;
+ static const uint8_t kOneMoreByteCode1 = 255;
+ static const uint8_t kLowestUCode = 253;
+ uint8_t code = 0;
+ if (!buf->ReadU8(&code)) {
+ return OTS_FAILURE();
+ }
+ if (code == kWordCode) {
+ uint16_t result = 0;
+ if (!buf->ReadU16(&result)) {
+ return OTS_FAILURE();
+ }
+ *value = result;
+ return true;
+ } else if (code == kOneMoreByteCode1) {
+ uint8_t result = 0;
+ if (!buf->ReadU8(&result)) {
+ return OTS_FAILURE();
+ }
+ *value = result + kLowestUCode;
+ return true;
+ } else if (code == kOneMoreByteCode2) {
+ uint8_t result = 0;
+ if (!buf->ReadU8(&result)) {
+ return OTS_FAILURE();
+ }
+ *value = result + kLowestUCode * 2;
+ return true;
+ } else {
+ *value = code;
+ return true;
+ }
+}
+
+bool ReadBase128(ots::Buffer* buf, uint32_t* value) {
+ uint32_t result = 0;
+ for (size_t i = 0; i < 5; ++i) {
+ uint8_t code = 0;
+ if (!buf->ReadU8(&code)) {
+ return OTS_FAILURE();
+ }
+ // If any of the top seven bits are set then we're about to overflow.
+ if (result & 0xfe000000U) {
+ return OTS_FAILURE();
+ }
+ result = (result << 7) | (code & 0x7f);
+ if ((code & 0x80) == 0) {
+ *value = result;
+ return true;
+ }
+ }
+ // Make sure not to exceed the size bound
+ return OTS_FAILURE();
+}
+
+// Caller must ensure that buffer overrun won't happen.
+// TODO(ksakamaoto): Consider creating 'writer' version of the Buffer class
+// and use it across the code.
+size_t StoreU32(uint8_t* dst, size_t offset, uint32_t x) {
+ dst[offset] = x >> 24;
+ dst[offset + 1] = (x >> 16) & 0xff;
+ dst[offset + 2] = (x >> 8) & 0xff;
+ dst[offset + 3] = x & 0xff;
+ return offset + 4;
+}
+
+size_t StoreU16(uint8_t* dst, size_t offset, uint16_t x) {
+ dst[offset] = x >> 8;
+ dst[offset + 1] = x & 0xff;
+ return offset + 2;
+}
+
+int WithSign(int flag, int baseval) {
+ assert(0 <= baseval && baseval < 65536);
+ return (flag & 1) ? baseval : -baseval;
+}
+
+bool TripletDecode(const uint8_t* flags_in, const uint8_t* in, size_t in_size,
+ unsigned int n_points, std::vector<Point>* result,
+ size_t* in_bytes_consumed) {
+ int x = 0;
+ int y = 0;
+
+ // Early return if |in| buffer is too small. Each point consumes 1-4 bytes.
+ if (n_points > in_size) {
+ return OTS_FAILURE();
+ }
+ unsigned int triplet_index = 0;
+
+ for (unsigned int i = 0; i < n_points; ++i) {
+ uint8_t flag = flags_in[i];
+ bool on_curve = !(flag >> 7);
+ flag &= 0x7f;
+ unsigned int n_data_bytes;
+ if (flag < 84) {
+ n_data_bytes = 1;
+ } else if (flag < 120) {
+ n_data_bytes = 2;
+ } else if (flag < 124) {
+ n_data_bytes = 3;
+ } else {
+ n_data_bytes = 4;
+ }
+ if (triplet_index + n_data_bytes > in_size ||
+ triplet_index + n_data_bytes < triplet_index) {
+ return OTS_FAILURE();
+ }
+ int dx, dy;
+ if (flag < 10) {
+ dx = 0;
+ dy = WithSign(flag, ((flag & 14) << 7) + in[triplet_index]);
+ } else if (flag < 20) {
+ dx = WithSign(flag, (((flag - 10) & 14) << 7) + in[triplet_index]);
+ dy = 0;
+ } else if (flag < 84) {
+ int b0 = flag - 20;
+ int b1 = in[triplet_index];
+ dx = WithSign(flag, 1 + (b0 & 0x30) + (b1 >> 4));
+ dy = WithSign(flag >> 1, 1 + ((b0 & 0x0c) << 2) + (b1 & 0x0f));
+ } else if (flag < 120) {
+ int b0 = flag - 84;
+ dx = WithSign(flag, 1 + ((b0 / 12) << 8) + in[triplet_index]);
+ dy = WithSign(flag >> 1,
+ 1 + (((b0 % 12) >> 2) << 8) + in[triplet_index + 1]);
+ } else if (flag < 124) {
+ int b2 = in[triplet_index + 1];
+ dx = WithSign(flag, (in[triplet_index] << 4) + (b2 >> 4));
+ dy = WithSign(flag >> 1, ((b2 & 0x0f) << 8) + in[triplet_index + 2]);
+ } else {
+ dx = WithSign(flag, (in[triplet_index] << 8) + in[triplet_index + 1]);
+ dy = WithSign(flag >> 1,
+ (in[triplet_index + 2] << 8) + in[triplet_index + 3]);
+ }
+ triplet_index += n_data_bytes;
+ // Possible overflow but coordinate values are not security sensitive
+ x += dx;
+ y += dy;
+ result->push_back(Point());
+ Point& back = result->back();
+ back.x = static_cast<int16_t>(x);
+ back.y = static_cast<int16_t>(y);
+ back.on_curve = on_curve;
+ }
+ *in_bytes_consumed = triplet_index;
+ return true;
+}
+
+// This function stores just the point data. On entry, dst points to the
+// beginning of a simple glyph. Returns true on success.
+bool StorePoints(const std::vector<Point>& points,
+ unsigned int n_contours, unsigned int instruction_length,
+ uint8_t* dst, size_t dst_size, size_t* glyph_size) {
+ // I believe that n_contours < 65536, in which case this is safe. However, a
+ // comment and/or an assert would be good.
+ unsigned int flag_offset = kEndPtsOfContoursOffset + 2 * n_contours + 2 +
+ instruction_length;
+ uint8_t last_flag = 0xff;
+ uint8_t repeat_count = 0;
+ int last_x = 0;
+ int last_y = 0;
+ unsigned int x_bytes = 0;
+ unsigned int y_bytes = 0;
+
+ for (size_t i = 0; i < points.size(); ++i) {
+ const Point& point = points.at(i);
+ uint8_t flag = point.on_curve ? kGlyfOnCurve : 0;
+ int dx = point.x - last_x;
+ int dy = point.y - last_y;
+ if (dx == 0) {
+ flag |= kGlyfThisXIsSame;
+ } else if (dx > -256 && dx < 256) {
+ flag |= kGlyfXShort | (dx > 0 ? kGlyfThisXIsSame : 0);
+ x_bytes += 1;
+ } else {
+ x_bytes += 2;
+ }
+ if (dy == 0) {
+ flag |= kGlyfThisYIsSame;
+ } else if (dy > -256 && dy < 256) {
+ flag |= kGlyfYShort | (dy > 0 ? kGlyfThisYIsSame : 0);
+ y_bytes += 1;
+ } else {
+ y_bytes += 2;
+ }
+
+ if (flag == last_flag && repeat_count != 255) {
+ dst[flag_offset - 1] |= kGlyfRepeat;
+ repeat_count++;
+ } else {
+ if (repeat_count != 0) {
+ if (flag_offset >= dst_size) {
+ return OTS_FAILURE();
+ }
+ dst[flag_offset++] = repeat_count;
+ }
+ if (flag_offset >= dst_size) {
+ return OTS_FAILURE();
+ }
+ dst[flag_offset++] = flag;
+ repeat_count = 0;
+ }
+ last_x = point.x;
+ last_y = point.y;
+ last_flag = flag;
+ }
+
+ if (repeat_count != 0) {
+ if (flag_offset >= dst_size) {
+ return OTS_FAILURE();
+ }
+ dst[flag_offset++] = repeat_count;
+ }
+ unsigned int xy_bytes = x_bytes + y_bytes;
+ if (xy_bytes < x_bytes ||
+ flag_offset + xy_bytes < flag_offset ||
+ flag_offset + xy_bytes > dst_size) {
+ return OTS_FAILURE();
+ }
+
+ int x_offset = flag_offset;
+ int y_offset = flag_offset + x_bytes;
+ last_x = 0;
+ last_y = 0;
+ for (size_t i = 0; i < points.size(); ++i) {
+ int dx = points.at(i).x - last_x;
+ if (dx == 0) {
+ // pass
+ } else if (dx > -256 && dx < 256) {
+ dst[x_offset++] = static_cast<uint8_t>(std::abs(dx));
+ } else {
+ // will always fit for valid input, but overflow is harmless
+ x_offset = StoreU16(dst, x_offset, static_cast<uint16_t>(dx));
+ }
+ last_x += dx;
+ int dy = points.at(i).y - last_y;
+ if (dy == 0) {
+ // pass
+ } else if (dy > -256 && dy < 256) {
+ dst[y_offset++] = static_cast<uint8_t>(std::abs(dy));
+ } else {
+ y_offset = StoreU16(dst, y_offset, static_cast<uint16_t>(dy));
+ }
+ last_y += dy;
+ }
+ *glyph_size = y_offset;
+ return true;
+}
+
+// Compute the bounding box of the coordinates, and store into a glyf buffer.
+// A precondition is that there are at least 10 bytes available.
+void ComputeBbox(const std::vector<Point>& points, uint8_t* dst) {
+ int16_t x_min = 0;
+ int16_t y_min = 0;
+ int16_t x_max = 0;
+ int16_t y_max = 0;
+
+ for (size_t i = 0; i < points.size(); ++i) {
+ int16_t x = points.at(i).x;
+ int16_t y = points.at(i).y;
+ if (i == 0 || x < x_min) x_min = x;
+ if (i == 0 || x > x_max) x_max = x;
+ if (i == 0 || y < y_min) y_min = y;
+ if (i == 0 || y > y_max) y_max = y;
+ }
+ size_t offset = 2;
+ offset = StoreU16(dst, offset, x_min);
+ offset = StoreU16(dst, offset, y_min);
+ offset = StoreU16(dst, offset, x_max);
+ offset = StoreU16(dst, offset, y_max);
+}
+
+// Process entire bbox stream. This is done as a separate pass to allow for
+// composite bbox computations (an optional more aggressive transform).
+bool ProcessBboxStream(ots::Buffer* bbox_stream, unsigned int n_glyphs,
+ const std::vector<uint32_t>& loca_values, uint8_t* glyf_buf,
+ size_t glyf_buf_length) {
+ const uint8_t* buf = bbox_stream->buffer();
+ if (n_glyphs >= 65536 || loca_values.size() != n_glyphs + 1) {
+ return OTS_FAILURE();
+ }
+ // Safe because n_glyphs is bounded
+ unsigned int bitmap_length = ((n_glyphs + 31) >> 5) << 2;
+ if (!bbox_stream->Skip(bitmap_length)) {
+ return OTS_FAILURE();
+ }
+ for (unsigned int i = 0; i < n_glyphs; ++i) {
+ if (buf[i >> 3] & (0x80 >> (i & 7))) {
+ uint32_t loca_offset = loca_values.at(i);
+ if (loca_values.at(i + 1) - loca_offset < kEndPtsOfContoursOffset) {
+ return OTS_FAILURE();
+ }
+ if (glyf_buf_length < 2 + 10 ||
+ loca_offset > glyf_buf_length - 2 - 10) {
+ return OTS_FAILURE();
+ }
+ if (!bbox_stream->Read(glyf_buf + loca_offset + 2, 8)) {
+ return OTS_FAILURE();
+ }
+ }
+ }
+ return true;
+}
+
+bool ProcessComposite(ots::Buffer* composite_stream, uint8_t* dst,
+ size_t dst_size, size_t* glyph_size, bool* have_instructions) {
+ size_t start_offset = composite_stream->offset();
+ bool we_have_instructions = false;
+
+ uint16_t flags = FLAG_MORE_COMPONENTS;
+ while (flags & FLAG_MORE_COMPONENTS) {
+ if (!composite_stream->ReadU16(&flags)) {
+ return OTS_FAILURE();
+ }
+ we_have_instructions |= (flags & FLAG_WE_HAVE_INSTRUCTIONS) != 0;
+ size_t arg_size = 2; // glyph index
+ if (flags & FLAG_ARG_1_AND_2_ARE_WORDS) {
+ arg_size += 4;
+ } else {
+ arg_size += 2;
+ }
+ if (flags & FLAG_WE_HAVE_A_SCALE) {
+ arg_size += 2;
+ } else if (flags & FLAG_WE_HAVE_AN_X_AND_Y_SCALE) {
+ arg_size += 4;
+ } else if (flags & FLAG_WE_HAVE_A_TWO_BY_TWO) {
+ arg_size += 8;
+ }
+ if (!composite_stream->Skip(arg_size)) {
+ return OTS_FAILURE();
+ }
+ }
+ size_t composite_glyph_size = composite_stream->offset() - start_offset;
+ if (composite_glyph_size + kCompositeGlyphBegin > dst_size) {
+ return OTS_FAILURE();
+ }
+ StoreU16(dst, 0, 0xffff); // nContours = -1 for composite glyph
+ std::memcpy(dst + kCompositeGlyphBegin,
+ composite_stream->buffer() + start_offset,
+ composite_glyph_size);
+ *glyph_size = kCompositeGlyphBegin + composite_glyph_size;
+ *have_instructions = we_have_instructions;
+ return true;
+}
+
+// Build TrueType loca table
+bool StoreLoca(const std::vector<uint32_t>& loca_values, int index_format,
+ uint8_t* dst, size_t dst_size) {
+ const uint64_t loca_size = loca_values.size();
+ const uint64_t offset_size = index_format ? 4 : 2;
+ if ((loca_size << 2) >> 2 != loca_size) {
+ return OTS_FAILURE();
+ }
+ // No integer overflow here (loca_size <= 2^16).
+ if (offset_size * loca_size > dst_size) {
+ return OTS_FAILURE();
+ }
+ size_t offset = 0;
+ for (size_t i = 0; i < loca_values.size(); ++i) {
+ uint32_t value = loca_values.at(i);
+ if (index_format) {
+ offset = StoreU32(dst, offset, value);
+ } else {
+ offset = StoreU16(dst, offset, static_cast<uint16_t>(value >> 1));
+ }
+ }
+ return true;
+}
+
+// Reconstruct entire glyf table based on transformed original
+bool ReconstructGlyf(const uint8_t* data, size_t data_size,
+ uint8_t* dst, size_t dst_size,
+ uint8_t* loca_buf, size_t loca_size) {
+ static const int kNumSubStreams = 7;
+ ots::Buffer file(data, data_size);
+ uint32_t version;
+ std::vector<std::pair<const uint8_t*, size_t> > substreams(kNumSubStreams);
+
+ if (!file.ReadU32(&version)) {
+ return OTS_FAILURE();
+ }
+ uint16_t num_glyphs;
+ uint16_t index_format;
+ if (!file.ReadU16(&num_glyphs) ||
+ !file.ReadU16(&index_format)) {
+ return OTS_FAILURE();
+ }
+ unsigned int offset = (2 + kNumSubStreams) * 4;
+ if (offset > data_size) {
+ return OTS_FAILURE();
+ }
+ // Invariant from here on: data_size >= offset
+ for (int i = 0; i < kNumSubStreams; ++i) {
+ uint32_t substream_size;
+ if (!file.ReadU32(&substream_size)) {
+ return OTS_FAILURE();
+ }
+ if (substream_size > data_size - offset) {
+ return OTS_FAILURE();
+ }
+ substreams.at(i) = std::make_pair(data + offset, substream_size);
+ offset += substream_size;
+ }
+ ots::Buffer n_contour_stream(substreams.at(0).first, substreams.at(0).second);
+ ots::Buffer n_points_stream(substreams.at(1).first, substreams.at(1).second);
+ ots::Buffer flag_stream(substreams.at(2).first, substreams.at(2).second);
+ ots::Buffer glyph_stream(substreams.at(3).first, substreams.at(3).second);
+ ots::Buffer composite_stream(substreams.at(4).first, substreams.at(4).second);
+ ots::Buffer bbox_stream(substreams.at(5).first, substreams.at(5).second);
+ ots::Buffer instruction_stream(substreams.at(6).first,
+ substreams.at(6).second);
+
+ std::vector<uint32_t> loca_values;
+ loca_values.reserve(num_glyphs + 1);
+ std::vector<uint16_t> n_points_vec;
+ std::vector<Point> points;
+ uint32_t loca_offset = 0;
+ for (unsigned int i = 0; i < num_glyphs; ++i) {
+ size_t glyph_size = 0;
+ uint16_t n_contours = 0;
+ if (!n_contour_stream.ReadU16(&n_contours)) {
+ return OTS_FAILURE();
+ }
+ uint8_t* glyf_dst = dst + loca_offset;
+ size_t glyf_dst_size = dst_size - loca_offset;
+ if (n_contours == 0xffff) {
+ // composite glyph
+ bool have_instructions = false;
+ uint16_t instruction_size = 0;
+ if (!ProcessComposite(&composite_stream, glyf_dst, glyf_dst_size,
+ &glyph_size, &have_instructions)) {
+ return OTS_FAILURE();
+ }
+ if (have_instructions) {
+ if (!Read255UShort(&glyph_stream, &instruction_size)) {
+ return OTS_FAILURE();
+ }
+ // No integer overflow here (instruction_size < 2^16).
+ if (instruction_size + 2U > glyf_dst_size - glyph_size) {
+ return OTS_FAILURE();
+ }
+ StoreU16(glyf_dst, glyph_size, instruction_size);
+ if (!instruction_stream.Read(glyf_dst + glyph_size + 2,
+ instruction_size)) {
+ return OTS_FAILURE();
+ }
+ glyph_size += instruction_size + 2;
+ }
+ } else if (n_contours > 0) {
+ // simple glyph
+ n_points_vec.clear();
+ points.clear();
+ uint32_t total_n_points = 0;
+ uint16_t n_points_contour;
+ for (uint32_t j = 0; j < n_contours; ++j) {
+ if (!Read255UShort(&n_points_stream, &n_points_contour)) {
+ return OTS_FAILURE();
+ }
+ n_points_vec.push_back(n_points_contour);
+ if (total_n_points + n_points_contour < total_n_points) {
+ return OTS_FAILURE();
+ }
+ total_n_points += n_points_contour;
+ }
+ uint32_t flag_size = total_n_points;
+ if (flag_size > flag_stream.length() - flag_stream.offset()) {
+ return OTS_FAILURE();
+ }
+ const uint8_t* flags_buf = flag_stream.buffer() + flag_stream.offset();
+ const uint8_t* triplet_buf = glyph_stream.buffer() +
+ glyph_stream.offset();
+ size_t triplet_size = glyph_stream.length() - glyph_stream.offset();
+ size_t triplet_bytes_consumed = 0;
+ if (!TripletDecode(flags_buf, triplet_buf, triplet_size, total_n_points,
+ &points, &triplet_bytes_consumed)) {
+ return OTS_FAILURE();
+ }
+ const uint32_t header_and_endpts_contours_size =
+ kEndPtsOfContoursOffset + 2 * n_contours;
+ if (glyf_dst_size < header_and_endpts_contours_size) {
+ return OTS_FAILURE();
+ }
+ StoreU16(glyf_dst, 0, n_contours);
+ ComputeBbox(points, glyf_dst);
+ size_t endpts_offset = kEndPtsOfContoursOffset;
+ int end_point = -1;
+ for (unsigned int contour_ix = 0; contour_ix < n_contours; ++contour_ix) {
+ end_point += n_points_vec.at(contour_ix);
+ if (end_point >= 65536) {
+ return OTS_FAILURE();
+ }
+ endpts_offset = StoreU16(glyf_dst, endpts_offset, static_cast<uint16_t>(end_point));
+ }
+ if (!flag_stream.Skip(flag_size)) {
+ return OTS_FAILURE();
+ }
+ if (!glyph_stream.Skip(triplet_bytes_consumed)) {
+ return OTS_FAILURE();
+ }
+ uint16_t instruction_size;
+ if (!Read255UShort(&glyph_stream, &instruction_size)) {
+ return OTS_FAILURE();
+ }
+ // No integer overflow here (instruction_size < 2^16).
+ if (glyf_dst_size - header_and_endpts_contours_size <
+ instruction_size + 2U) {
+ return OTS_FAILURE();
+ }
+ uint8_t* instruction_dst = glyf_dst + header_and_endpts_contours_size;
+ StoreU16(instruction_dst, 0, instruction_size);
+ if (!instruction_stream.Read(instruction_dst + 2, instruction_size)) {
+ return OTS_FAILURE();
+ }
+ if (!StorePoints(points, n_contours, instruction_size,
+ glyf_dst, glyf_dst_size, &glyph_size)) {
+ return OTS_FAILURE();
+ }
+ } else {
+ glyph_size = 0;
+ }
+ loca_values.push_back(loca_offset);
+ if (glyph_size + 3 < glyph_size) {
+ return OTS_FAILURE();
+ }
+ glyph_size = ots::Round2(glyph_size);
+ if (glyph_size > dst_size - loca_offset) {
+ // This shouldn't happen, but this test defensively maintains the
+ // invariant that loca_offset <= dst_size.
+ return OTS_FAILURE();
+ }
+ loca_offset += glyph_size;
+ }
+ loca_values.push_back(loca_offset);
+ assert(loca_values.size() == static_cast<size_t>(num_glyphs + 1));
+ if (!ProcessBboxStream(&bbox_stream, num_glyphs, loca_values,
+ dst, dst_size)) {
+ return OTS_FAILURE();
+ }
+ return StoreLoca(loca_values, index_format, loca_buf, loca_size);
+}
+
+// This is linear search, but could be changed to binary because we
+// do have a guarantee that the tables are sorted by tag. But the total
+// cpu time is expected to be very small in any case.
+const Table* FindTable(const std::vector<Table>& tables, uint32_t tag) {
+ size_t n_tables = tables.size();
+ for (size_t i = 0; i < n_tables; ++i) {
+ if (tables.at(i).tag == tag) {
+ return &tables.at(i);
+ }
+ }
+ return NULL;
+}
+
+bool ReconstructTransformed(const std::vector<Table>& tables, uint32_t tag,
+ const uint8_t* transformed_buf, size_t transformed_size,
+ uint8_t* dst, size_t dst_length) {
+ if (tag == TAG('g', 'l', 'y', 'f')) {
+ const Table* glyf_table = FindTable(tables, tag);
+ const Table* loca_table = FindTable(tables, TAG('l', 'o', 'c', 'a'));
+ if (glyf_table == NULL || loca_table == NULL) {
+ return OTS_FAILURE();
+ }
+ if (static_cast<uint64_t>(glyf_table->dst_offset) + glyf_table->dst_length >
+ dst_length) {
+ return OTS_FAILURE();
+ }
+ if (static_cast<uint64_t>(loca_table->dst_offset) + loca_table->dst_length >
+ dst_length) {
+ return OTS_FAILURE();
+ }
+ return ReconstructGlyf(transformed_buf, transformed_size,
+ dst + glyf_table->dst_offset, glyf_table->dst_length,
+ dst + loca_table->dst_offset, loca_table->dst_length);
+ } else if (tag == TAG('l', 'o', 'c', 'a')) {
+ // processing was already done by glyf table, but validate
+ if (!FindTable(tables, TAG('g', 'l', 'y', 'f'))) {
+ return OTS_FAILURE();
+ }
+ } else {
+ // transform for the tag is not known
+ return OTS_FAILURE();
+ }
+ return true;
+}
+
+uint32_t ComputeChecksum(const uint8_t* buf, size_t size) {
+ uint32_t checksum = 0;
+ for (size_t i = 0; i < size; i += 4) {
+ // We assume the addition is mod 2^32, which is valid because unsigned
+ checksum += (buf[i] << 24) | (buf[i + 1] << 16) |
+ (buf[i + 2] << 8) | buf[i + 3];
+ }
+ return checksum;
+}
+
+bool FixChecksums(const std::vector<Table>& tables, uint8_t* dst) {
+ const Table* head_table = FindTable(tables, TAG('h', 'e', 'a', 'd'));
+ if (head_table == NULL ||
+ head_table->dst_length < kCheckSumAdjustmentOffset + 4) {
+ return OTS_FAILURE();
+ }
+ size_t adjustment_offset = head_table->dst_offset + kCheckSumAdjustmentOffset;
+ if (adjustment_offset < head_table->dst_offset) {
+ return OTS_FAILURE();
+ }
+ StoreU32(dst, adjustment_offset, 0);
+ size_t n_tables = tables.size();
+ uint32_t file_checksum = 0;
+ for (size_t i = 0; i < n_tables; ++i) {
+ const Table* table = &tables.at(i);
+ size_t table_length = table->dst_length;
+ uint8_t* table_data = dst + table->dst_offset;
+ uint32_t checksum = ComputeChecksum(table_data, table_length);
+ StoreU32(dst, kSfntHeaderSize + i * kSfntEntrySize + 4, checksum);
+ file_checksum += checksum; // The addition is mod 2^32
+ }
+ file_checksum += ComputeChecksum(dst,
+ kSfntHeaderSize + kSfntEntrySize * n_tables);
+ uint32_t checksum_adjustment = 0xb1b0afba - file_checksum;
+ StoreU32(dst, adjustment_offset, checksum_adjustment);
+ return true;
+}
+
+bool Woff2Uncompress(uint8_t* dst_buf, size_t dst_size,
+ const uint8_t* src_buf, size_t src_size) {
+ size_t uncompressed_size = dst_size;
+ int ok = BrotliDecompressBuffer(src_size, src_buf,
+ &uncompressed_size, dst_buf);
+ if (!ok || uncompressed_size != dst_size) {
+ return OTS_FAILURE();
+ }
+ return true;
+}
+
+bool ReadTableDirectory(ots::OpenTypeFile* file,
+ ots::Buffer* buffer, std::vector<Table>* tables,
+ size_t num_tables) {
+ for (size_t i = 0; i < num_tables; ++i) {
+ Table* table = &tables->at(i);
+ uint8_t flag_byte;
+ if (!buffer->ReadU8(&flag_byte)) {
+ return OTS_FAILURE_MSG("Failed to read the flags of table directory entry %d", i);
+ }
+ uint32_t tag;
+ if ((flag_byte & 0x3f) == 0x3f) {
+ if (!buffer->ReadU32(&tag)) {
+ return OTS_FAILURE_MSG("Failed to read the tag of table directory entry %d", i);
+ }
+ } else {
+ tag = kKnownTags[flag_byte & 0x3f];
+ }
+ // Bits 6 and 7 are reserved and must be 0.
+ if ((flag_byte & 0xc0) != 0) {
+ return OTS_FAILURE_MSG("Bits 6 and 7 are not 0 for table directory entry %d", i);
+ }
+ uint32_t flags = 0;
+ // Always transform the glyf and loca tables
+ if (tag == TAG('g', 'l', 'y', 'f') ||
+ tag == TAG('l', 'o', 'c', 'a')) {
+ flags |= kWoff2FlagsTransform;
+ }
+ uint32_t dst_length;
+ if (!ReadBase128(buffer, &dst_length)) {
+ return OTS_FAILURE_MSG("Failed to read \"origLength\" for table %4.4s", (char*)&tag);
+ }
+ uint32_t transform_length = dst_length;
+ if ((flags & kWoff2FlagsTransform) != 0) {
+ if (!ReadBase128(buffer, &transform_length)) {
+ return OTS_FAILURE_MSG("Failed to read \"transformLength\" for table %4.4s", (char*)&tag);
+ }
+ }
+ // Disallow huge numbers (> 1GB) for sanity.
+ if (transform_length > 1024 * 1024 * 1024 ||
+ dst_length > 1024 * 1024 * 1024) {
+ return OTS_FAILURE_MSG("\"origLength\" or \"transformLength\" > 1GB");
+ }
+ table->tag = tag;
+ table->flags = flags;
+ table->transform_length = transform_length;
+ table->dst_length = dst_length;
+ }
+ return true;
+}
+
+} // namespace
+
+namespace ots {
+
+size_t ComputeWOFF2FinalSize(const uint8_t* data, size_t length) {
+ ots::Buffer file(data, length);
+ uint32_t total_length;
+
+ if (!file.Skip(16) ||
+ !file.ReadU32(&total_length)) {
+ return 0;
+ }
+ return total_length;
+}
+
+bool ConvertWOFF2ToTTF(ots::OpenTypeFile* file,
+ uint8_t* result, size_t result_length,
+ const uint8_t* data, size_t length) {
+ static const uint32_t kWoff2Signature = 0x774f4632; // "wOF2"
+ ots::Buffer buffer(data, length);
+
+ uint32_t signature;
+ uint32_t flavor = 0;
+ if (!buffer.ReadU32(&signature) || signature != kWoff2Signature ||
+ !buffer.ReadU32(&flavor)) {
+ return OTS_FAILURE_MSG("Failed to read \"signature\" or \"flavor\", or not WOFF2 signature");
+ }
+
+ if (!IsValidVersionTag(ntohl(flavor))) {
+ return OTS_FAILURE_MSG("Invalid \"flavor\"");
+ }
+
+ uint32_t reported_length;
+ if (!buffer.ReadU32(&reported_length) || length != reported_length) {
+ return OTS_FAILURE_MSG("Failed to read \"length\" or it does not match the actual file size");
+ }
+ uint16_t num_tables;
+ if (!buffer.ReadU16(&num_tables) || !num_tables) {
+ return OTS_FAILURE_MSG("Failed to read \"numTables\"");
+ }
+ // We don't care about these fields of the header:
+ // uint16_t reserved
+ // uint32_t total_sfnt_size
+ if (!buffer.Skip(6)) {
+ return OTS_FAILURE_MSG("Failed to read \"reserve\" or \"totalSfntSize\"");
+ }
+ uint32_t compressed_length;
+ if (!buffer.ReadU32(&compressed_length)) {
+ return OTS_FAILURE_MSG("Failed to read \"totalCompressedSize\"");
+ }
+ if (compressed_length > std::numeric_limits<uint32_t>::max()) {
+ return OTS_FAILURE();
+ }
+
+ // We don't care about these fields of the header:
+ // uint16_t major_version, minor_version
+ // uint32_t meta_offset, meta_length, meta_orig_length
+ // uint32_t priv_offset, priv_length
+ if (!buffer.Skip(24)) {
+ return OTS_FAILURE();
+ }
+ std::vector<Table> tables(num_tables);
+ if (!ReadTableDirectory(file, &buffer, &tables, num_tables)) {
+ return OTS_FAILURE_MSG("Failed to read table directory");
+ }
+ uint64_t compressed_offset = buffer.offset();
+ if (compressed_offset > std::numeric_limits<uint32_t>::max()) {
+ return OTS_FAILURE();
+ }
+ uint64_t dst_offset = kSfntHeaderSize +
+ kSfntEntrySize * static_cast<uint64_t>(num_tables);
+ for (uint16_t i = 0; i < num_tables; ++i) {
+ Table* table = &tables.at(i);
+ table->dst_offset = static_cast<uint32_t>(dst_offset);
+ dst_offset += table->dst_length;
+ if (dst_offset > std::numeric_limits<uint32_t>::max()) {
+ return OTS_FAILURE();
+ }
+ dst_offset = ots::Round4(dst_offset);
+ }
+ if (ots::Round4(compressed_offset + compressed_length) > length || dst_offset > result_length) {
+ return OTS_FAILURE();
+ }
+
+ const uint32_t sfnt_header_and_table_directory_size = 12 + 16 * num_tables;
+ if (sfnt_header_and_table_directory_size > result_length) {
+ return OTS_FAILURE();
+ }
+
+ // Start building the font
+ size_t offset = 0;
+ offset = StoreU32(result, offset, flavor);
+ offset = StoreU16(result, offset, num_tables);
+ uint8_t max_pow2 = 0;
+ while (1u << (max_pow2 + 1) <= num_tables) {
+ max_pow2++;
+ }
+ const uint16_t output_search_range = (1u << max_pow2) << 4;
+ offset = StoreU16(result, offset, output_search_range);
+ offset = StoreU16(result, offset, max_pow2);
+ offset = StoreU16(result, offset, (num_tables << 4) - output_search_range);
+ for (uint16_t i = 0; i < num_tables; ++i) {
+ const Table* table = &tables.at(i);
+ offset = StoreU32(result, offset, table->tag);
+ offset = StoreU32(result, offset, 0); // checksum, to fill in later
+ offset = StoreU32(result, offset, table->dst_offset);
+ offset = StoreU32(result, offset, table->dst_length);
+ }
+ std::vector<uint8_t> uncompressed_buf;
+ const uint8_t* transform_buf = NULL;
+ uint64_t total_size = 0;
+
+ for (uint16_t i = 0; i < num_tables; ++i) {
+ total_size += tables.at(i).transform_length;
+ if (total_size > std::numeric_limits<uint32_t>::max()) {
+ return OTS_FAILURE();
+ }
+ }
+ // Enforce same 30M limit on uncompressed tables as OTS
+ if (total_size > 30 * 1024 * 1024) {
+ return OTS_FAILURE();
+ }
+ const size_t total_size_size_t = static_cast<size_t>(total_size);
+ uncompressed_buf.resize(total_size_size_t);
+ const uint8_t* src_buf = data + compressed_offset;
+ if (!Woff2Uncompress(&uncompressed_buf[0], total_size_size_t,
+ src_buf, compressed_length)) {
+ return OTS_FAILURE();
+ }
+ transform_buf = &uncompressed_buf[0];
+
+ for (uint16_t i = 0; i < num_tables; ++i) {
+ const Table* table = &tables.at(i);
+ uint32_t flags = table->flags;
+ size_t transform_length = table->transform_length;
+
+ if ((flags & kWoff2FlagsTransform) == 0) {
+ if (transform_length != table->dst_length) {
+ return OTS_FAILURE();
+ }
+ if (static_cast<uint64_t>(table->dst_offset) + transform_length >
+ result_length) {
+ return OTS_FAILURE();
+ }
+ std::memcpy(result + table->dst_offset, transform_buf,
+ transform_length);
+ } else {
+ if (!ReconstructTransformed(tables, table->tag,
+ transform_buf, transform_length, result, result_length)) {
+ return OTS_FAILURE();
+ }
+ }
+
+ transform_buf += transform_length;
+ if (transform_buf > &uncompressed_buf[0] + uncompressed_buf.size()) {
+ return OTS_FAILURE();
+ }
+ }
+
+ return FixChecksums(tables, result);
+}
+
+} // namespace ots
+
+#undef TABLE_NAME
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