Stop trusting header totalSfntSize and glyf origLength

src/file.h

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
-// File IO helpers
+// File IO helpers.
 
 #ifndef WOFF2_FILE_H_
 #define WOFF2_FILE_H_
@@ -22,18 +22,20 @@
 
 namespace woff2 {
 
-inline std::string GetFileContent(std::string filename) {
+using std::string;
+
+
+inline string GetFileContent(string filename) {
   std::ifstream ifs(filename.c_str(), std::ios::binary);
-  return std::string(
+  return string(
     std::istreambuf_iterator<char>(ifs.rdbuf()),
     std::istreambuf_iterator<char>());
 }
 
-inline void SetFileContents(std::string filename, std::string content) {
+inline void SetFileContents(string filename, string::iterator start,
+    string::iterator end) {
   std::ofstream ofs(filename.c_str(), std::ios::binary);
-  std::copy(content.begin(),
-            content.end(),
-            std::ostream_iterator<char>(ofs));
+  std::copy(start, end, std::ostream_iterator<char>(ofs));
 }
 
 } // namespace woff2

src/font.cc

@@ -49,11 +49,7 @@ std::vector<uint32_t> Font::OutputOrderedTags() const {
     output_order.push_back(table.tag);
   }
 
-  // Alphabetize and do not put loca immediately after glyf
-  // This violates woff2 spec but results in a font that passes OTS
-  std::sort(output_order.begin(), output_order.end());
-  // TODO(user): change to match spec once browsers are on newer OTS
-  /*
+  // Alphabetize then put loca immediately after glyf
   auto glyf_loc = std::find(output_order.begin(), output_order.end(),
       kGlyfTableTag);
   auto loca_loc = std::find(output_order.begin(), output_order.end(),
@@ -62,7 +58,7 @@ std::vector<uint32_t> Font::OutputOrderedTags() const {
     output_order.erase(loca_loc);
     output_order.insert(std::find(output_order.begin(), output_order.end(),
       kGlyfTableTag) + 1, kLocaTableTag);
-  }*/
+  }
 
   return output_order;
 }

src/store_bytes.h

@@ -58,8 +58,7 @@ inline void Store16(int val, size_t* offset, uint8_t* dst) {
       ((val & 0xFF) << 8) | ((val & 0xFF00) >> 8);
   *offset += 2;
 #elif (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
-  *reinterpret_cast<uint16_t*>(dst + *offset) =
-      static_cast<uint16_t>(val);
+  *reinterpret_cast<uint16_t*>(dst + *offset) = static_cast<uint16_t>(val);
   *offset += 2;
 #else
   dst[(*offset)++] = val >> 8;

src/woff2_common.cc

@@ -23,7 +23,8 @@ namespace woff2 {
 
 uint32_t ComputeULongSum(const uint8_t* buf, size_t size) {
   uint32_t checksum = 0;
-  for (size_t i = 0; i < size; i += 4) {
+  size_t aligned_size = size & ~3;
+  for (size_t i = 0; i < aligned_size; i += 4) {
 #if (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
     uint32_t v = *reinterpret_cast<const uint32_t*>(buf + i);
     checksum += (((v & 0xFF) << 24) | ((v & 0xFF00) << 8) |
@@ -35,6 +36,16 @@ uint32_t ComputeULongSum(const uint8_t* buf, size_t size) {
       (buf[i + 2] << 8) | buf[i + 3];
 #endif
   }
+
+  // treat size not aligned on 4 as if it were padded to 4 with 0's
+  if (size != aligned_size) {
+    uint32_t v = 0;
+    for (size_t i = aligned_size; i < size; ++i) {
+      v |= buf[i] << (24 - 8 * (i & 3));
+    }
+    checksum += v;
+  }
+
   return checksum;
 }
 

src/woff2_compress.cc

@@ -47,7 +47,7 @@ int main(int argc, char **argv) {
   }
   output.resize(output_size);
 
-  woff2::SetFileContents(outfilename, output);
+  woff2::SetFileContents(outfilename, output.begin(), output.end());
 
   return 0;
 }

src/woff2_dec.h

@@ -19,6 +19,7 @@
 
 #include <stddef.h>
 #include <inttypes.h>
+#include "./woff2_out.h"
 
 namespace woff2 {
 
@@ -31,6 +32,11 @@ size_t ComputeWOFF2FinalSize(const uint8_t *data, size_t length);
 bool ConvertWOFF2ToTTF(uint8_t *result, size_t result_length,
                        const uint8_t *data, size_t length);
 
+// Decompresses the font into out. Returns true on success.
+// Works even if WOFF2Header totalSfntSize is wrong.
+bool ConvertWOFF2ToTTF(const uint8_t *data, size_t length,
+                       WOFF2Out* out);
+
 } // namespace woff2
 
 #endif  // WOFF2_WOFF2_DEC_H_

src/woff2_decompress.cc

@@ -17,10 +17,10 @@
 
 #include <string>
 
-
-#include "file.h"
+#include "./file.h"
 #include "./woff2_dec.h"
 
+
 int main(int argc, char **argv) {
   using std::string;
 
@@ -31,24 +31,18 @@ int main(int argc, char **argv) {
 
   string filename(argv[1]);
   string outfilename = filename.substr(0, filename.find_last_of(".")) + ".ttf";
-  fprintf(stdout, "Processing %s => %s\n",
-    filename.c_str(), outfilename.c_str());
+
   string input = woff2::GetFileContent(filename);
+  const uint8_t* raw_input = reinterpret_cast<const uint8_t*>(input.data());
+  string output(std::min(woff2::ComputeWOFF2FinalSize(raw_input, input.size()),
+                         woff2::kDefaultMaxSize), 0);
+  woff2::WOFF2StringOut out(&output);
 
-  size_t decompressed_size = woff2::ComputeWOFF2FinalSize(
-      reinterpret_cast<const uint8_t*>(input.data()), input.size());
-  string output(decompressed_size, 0);
-  const bool ok = woff2::ConvertWOFF2ToTTF(
-      reinterpret_cast<uint8_t*>(&output[0]), decompressed_size,
-      reinterpret_cast<const uint8_t*>(input.data()), input.size());
+  const bool ok = woff2::ConvertWOFF2ToTTF(raw_input, input.size(), &out);
 
-  if (!ok) {
-    fprintf(stderr, "Decompression failed\n");
-    return 1;
+  if (ok) {
+    woff2::SetFileContents(outfilename, output.begin(),
+        output.begin() + out.Size());
   }
-
-  woff2::SetFileContents(outfilename, output);
-
-  return 0;
+  return ok ? 0 : 1;
 }
-

src/woff2_enc.cc

@@ -23,8 +23,8 @@
 #include <string>
 #include <vector>
 
-#include "./buffer.h"
 #include "./encode.h"
+#include "./buffer.h"
 #include "./font.h"
 #include "./normalize.h"
 #include "./round.h"
@@ -47,6 +47,7 @@ using std::vector;
 const size_t kWoff2HeaderSize = 48;
 const size_t kWoff2EntrySize = 20;
 
+
 bool Compress(const uint8_t* data, const size_t len,
               uint8_t* result, uint32_t* result_len,
               brotli::BrotliParams::Mode mode, int quality) {

src/woff2_out.cc

@@ -0,0 +1,73 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Output buffer for WOFF2 decompression.
+
+#include "./woff2_out.h"
+
+namespace woff2 {
+
+WOFF2StringOut::WOFF2StringOut(string* buf)
+  : buf_(buf),
+    max_size_(kDefaultMaxSize),
+    offset_(0) {}
+
+bool WOFF2StringOut::Write(const void *buf, size_t n) {
+  return Write(buf, offset_, n);
+}
+
+bool WOFF2StringOut::Write(const void *buf, size_t offset, size_t n) {
+  if (offset > max_size_ || n > max_size_ - offset) {
+    return false;
+  }
+  if (offset == buf_->size()) {
+    buf_->append(static_cast<const char*>(buf), n);
+  } else {
+    if (offset + n > buf_->size()) {
+      buf_->append(offset + n - buf_->size(), 0);
+    }
+    buf_->replace(offset, n, static_cast<const char*>(buf), n);
+  }
+  offset_ = std::max(offset_, offset + n);
+
+  return true;
+}
+
+void WOFF2StringOut::SetMaxSize(size_t max_size) {
+  max_size_ = max_size;
+  if (offset_ > max_size_) {
+    offset_ = max_size_;
+  }
+}
+
+WOFF2MemoryOut::WOFF2MemoryOut(uint8_t* buf, size_t buf_size)
+  : buf_(buf),
+    buf_size_(buf_size),
+    offset_(0) {}
+
+bool WOFF2MemoryOut::Write(const void *buf, size_t n) {
+  return Write(buf, offset_, n);
+}
+
+bool WOFF2MemoryOut::Write(const void *buf, size_t offset, size_t n) {
+  if (offset > buf_size_ || n > buf_size_ - offset) {
+    return false;
+  }
+  std::memcpy(buf_ + offset, buf, n);
+  offset_ = std::max(offset_, offset + n);
+
+  return true;
+}
+
+} // namespace woff2

src/woff2_out.h

@@ -0,0 +1,113 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Output buffer for WOFF2 decompression.
+
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Output buffer for WOFF2 decompression.
+
+#ifndef WOFF2_WOFF2_OUT_H_
+#define WOFF2_WOFF2_OUT_H_
+
+#include <algorithm>
+#include <cstring>
+#include <memory>
+#include "./port.h"
+
+namespace woff2 {
+
+// Suggested max size for output.
+const size_t kDefaultMaxSize = 30 * 1024 * 1024;
+
+using std::string;
+
+
+/**
+ * Output interface for the woff2 decoding.
+ *
+ * Writes to arbitrary offsets are supported to facilitate updating offset
+ * table and checksums after tables are ready. Reading the current size is
+ * supported so a 'loca' table can be built up while writing glyphs.
+ *
+ * By default limits size to kDefaultMaxSize.
+ */
+class WOFF2Out {
+ public:
+  virtual ~WOFF2Out(void) {}
+
+  // Append n bytes of data from buf.
+  // Return true if all written, false otherwise.
+  virtual bool Write(const void *buf, size_t n) = 0;
+
+  // Write n bytes of data from buf at offset.
+  // Return true if all written, false otherwise.
+  virtual bool Write(const void *buf, size_t offset, size_t n) = 0;
+
+  virtual size_t Size() = 0;
+};
+
+/**
+ * Expanding memory block for woff2 out. By default limited to kDefaultMaxSize.
+ */
+class WOFF2StringOut : public WOFF2Out {
+ public:
+  // Create a writer that writes its data to buf.
+  // buf->size() will grow to at most max_size
+  // buf may be sized (e.g. using EstimateWOFF2FinalSize) or empty.
+  explicit WOFF2StringOut(string* buf);
+
+  bool Write(const void *buf, size_t n) override;
+  bool Write(const void *buf, size_t offset, size_t n) override;
+  size_t Size() override { return offset_; }
+  size_t MaxSize() { return max_size_; }
+  void SetMaxSize(size_t max_size);
+ private:
+  string* buf_;
+  size_t max_size_;
+  size_t offset_;
+};
+
+/**
+ * Fixed memory block for woff2 out.
+ */
+class WOFF2MemoryOut : public WOFF2Out {
+ public:
+  // Create a writer that writes its data to buf.
+  WOFF2MemoryOut(uint8_t* buf, size_t buf_size);
+
+  bool Write(const void *buf, size_t n) override;
+  bool Write(const void *buf, size_t offset, size_t n) override;
+  size_t Size() override { return offset_; }
+ private:
+  uint8_t* buf_;
+  size_t buf_size_;
+  size_t offset_;
+};
+
+} // namespace woff2
+
+#endif  // WOFF2_WOFF2_OUT_H_