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Diffstat (limited to 'gfx/ots/src/cff.cc')
| -rw-r--r-- | gfx/ots/src/cff.cc | 1381 |
1 files changed, 1381 insertions, 0 deletions
diff --git a/gfx/ots/src/cff.cc b/gfx/ots/src/cff.cc new file mode 100644 index 0000000000..af54a4a16c --- /dev/null +++ b/gfx/ots/src/cff.cc @@ -0,0 +1,1381 @@ +// Copyright (c) 2012-2017 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. + +#include "cff.h" + +#include <cstring> +#include <utility> +#include <vector> + +#include "maxp.h" +#include "cff_charstring.h" +#include "variations.h" + +// CFF - PostScript font program (Compact Font Format) table +// http://www.microsoft.com/typography/otspec/cff.htm +// http://www.microsoft.com/typography/otspec/cffspec.htm + +#define TABLE_NAME "CFF" + +namespace { + +enum DICT_OPERAND_TYPE { + DICT_OPERAND_INTEGER, + DICT_OPERAND_REAL, + DICT_OPERATOR, +}; + +enum DICT_DATA_TYPE { + DICT_DATA_TOPLEVEL, + DICT_DATA_FDARRAY, + DICT_DATA_PRIVATE, +}; + +enum FONT_FORMAT { + FORMAT_UNKNOWN, + FORMAT_CID_KEYED, + FORMAT_OTHER, // Including synthetic fonts +}; + +// see Appendix. A +const size_t kNStdString = 390; + +typedef std::pair<uint32_t, DICT_OPERAND_TYPE> Operand; + +bool ReadOffset(ots::Buffer &table, uint8_t off_size, uint32_t *offset) { + if (off_size > 4) { + return OTS_FAILURE(); + } + + uint32_t tmp32 = 0; + for (unsigned i = 0; i < off_size; ++i) { + uint8_t tmp8 = 0; + if (!table.ReadU8(&tmp8)) { + return OTS_FAILURE(); + } + tmp32 <<= 8; + tmp32 += tmp8; + } + *offset = tmp32; + return true; +} + +bool ParseIndex(ots::Buffer &table, ots::CFFIndex &index, bool cff2 = false) { + index.off_size = 0; + index.offsets.clear(); + + if (cff2) { + if (!table.ReadU32(&(index.count))) { + return OTS_FAILURE(); + } + } else { + uint16_t count; + if (!table.ReadU16(&count)) { + return OTS_FAILURE(); + } + index.count = count; + } + + if (index.count == 0) { + // An empty INDEX. + index.offset_to_next = table.offset(); + return true; + } + + if (!table.ReadU8(&(index.off_size))) { + return OTS_FAILURE(); + } + if (index.off_size < 1 || index.off_size > 4) { + return OTS_FAILURE(); + } + + const size_t array_size = (index.count + 1) * index.off_size; + // less than ((64k + 1) * 4), thus does not overflow. + const size_t object_data_offset = table.offset() + array_size; + // does not overflow too, since offset() <= 1GB. + + if (object_data_offset >= table.length()) { + return OTS_FAILURE(); + } + + for (unsigned i = 0; i <= index.count; ++i) { // '<=' is not a typo. + uint32_t rel_offset = 0; + if (!ReadOffset(table, index.off_size, &rel_offset)) { + return OTS_FAILURE(); + } + if (rel_offset < 1) { + return OTS_FAILURE(); + } + if (i == 0 && rel_offset != 1) { + return OTS_FAILURE(); + } + + if (rel_offset > table.length()) { + return OTS_FAILURE(); + } + + // does not underflow. + if (object_data_offset > table.length() - (rel_offset - 1)) { + return OTS_FAILURE(); + } + + index.offsets.push_back( + object_data_offset + (rel_offset - 1)); // less than length(), 1GB. + } + + for (unsigned i = 1; i < index.offsets.size(); ++i) { + // We allow consecutive identical offsets here for zero-length strings. + // See http://crbug.com/69341 for more details. + if (index.offsets[i] < index.offsets[i - 1]) { + return OTS_FAILURE(); + } + } + + index.offset_to_next = index.offsets.back(); + return true; +} + +bool ParseNameData( + ots::Buffer *table, const ots::CFFIndex &index, std::string* out_name) { + uint8_t name[256] = {0}; + + const size_t length = index.offsets[1] - index.offsets[0]; + // font names should be no longer than 127 characters. + if (length > 127) { + return OTS_FAILURE(); + } + + table->set_offset(index.offsets[0]); + if (!table->Read(name, length)) { + return OTS_FAILURE(); + } + + for (size_t i = 0; i < length; ++i) { + // setting the first byte to NUL is allowed. + if (i == 0 && name[i] == 0) continue; + // non-ASCII characters are not recommended (except the first character). + if (name[i] < 33 || name[i] > 126) { + return OTS_FAILURE(); + } + // [, ], ... are not allowed. + if (std::strchr("[](){}<>/% ", name[i])) { + return OTS_FAILURE(); + } + } + + *out_name = reinterpret_cast<char *>(name); + return true; +} + +bool CheckOffset(const Operand& operand, size_t table_length) { + if (operand.second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (operand.first >= table_length) { + return OTS_FAILURE(); + } + return true; +} + +bool CheckSid(const Operand& operand, size_t sid_max) { + if (operand.second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (operand.first > sid_max) { + return OTS_FAILURE(); + } + return true; +} + +bool ParseDictDataBcd(ots::Buffer &table, std::vector<Operand> &operands) { + bool read_decimal_point = false; + bool read_e = false; + + uint8_t nibble = 0; + size_t count = 0; + while (true) { + if (!table.ReadU8(&nibble)) { + return OTS_FAILURE(); + } + if ((nibble & 0xf0) == 0xf0) { + if ((nibble & 0xf) == 0xf) { + // TODO(yusukes): would be better to store actual double value, + // rather than the dummy integer. + operands.push_back(std::make_pair(static_cast<uint32_t>(0), + DICT_OPERAND_REAL)); + return true; + } + return OTS_FAILURE(); + } + if ((nibble & 0x0f) == 0x0f) { + operands.push_back(std::make_pair(static_cast<uint32_t>(0), + DICT_OPERAND_REAL)); + return true; + } + + // check number format + uint8_t nibbles[2]; + nibbles[0] = (nibble & 0xf0) >> 8; + nibbles[1] = (nibble & 0x0f); + for (unsigned i = 0; i < 2; ++i) { + if (nibbles[i] == 0xd) { // reserved number + return OTS_FAILURE(); + } + if ((nibbles[i] == 0xe) && // minus + ((count > 0) || (i > 0))) { + return OTS_FAILURE(); // minus sign should be the first character. + } + if (nibbles[i] == 0xa) { // decimal point + if (!read_decimal_point) { + read_decimal_point = true; + } else { + return OTS_FAILURE(); // two or more points. + } + } + if ((nibbles[i] == 0xb) || // E+ + (nibbles[i] == 0xc)) { // E- + if (!read_e) { + read_e = true; + } else { + return OTS_FAILURE(); // two or more E's. + } + } + } + ++count; + } +} + +bool ParseDictDataEscapedOperator(ots::Buffer &table, + std::vector<Operand> &operands) { + uint8_t op = 0; + if (!table.ReadU8(&op)) { + return OTS_FAILURE(); + } + + if ((op <= 14) || + (op >= 17 && op <= 23) || + (op >= 30 && op <= 38)) { + operands.push_back(std::make_pair((12U << 8) + op, DICT_OPERATOR)); + return true; + } + + // reserved area. + return OTS_FAILURE(); +} + +bool ParseDictDataNumber(ots::Buffer &table, uint8_t b0, + std::vector<Operand> &operands) { + uint8_t b1 = 0; + uint8_t b2 = 0; + uint8_t b3 = 0; + uint8_t b4 = 0; + + switch (b0) { + case 28: // shortint + if (!table.ReadU8(&b1) || + !table.ReadU8(&b2)) { + return OTS_FAILURE(); + } + operands.push_back(std::make_pair( + static_cast<uint32_t>((b1 << 8) + b2), DICT_OPERAND_INTEGER)); + return true; + + case 29: // longint + if (!table.ReadU8(&b1) || + !table.ReadU8(&b2) || + !table.ReadU8(&b3) || + !table.ReadU8(&b4)) { + return OTS_FAILURE(); + } + operands.push_back(std::make_pair( + static_cast<uint32_t>((b1 << 24) + (b2 << 16) + (b3 << 8) + b4), + DICT_OPERAND_INTEGER)); + return true; + + case 30: // binary coded decimal + return ParseDictDataBcd(table, operands); + + default: + break; + } + + uint32_t result; + if (b0 >=32 && b0 <=246) { + result = b0 - 139; + } else if (b0 >=247 && b0 <= 250) { + if (!table.ReadU8(&b1)) { + return OTS_FAILURE(); + } + result = (b0 - 247) * 256 + b1 + 108; + } else if (b0 >= 251 && b0 <= 254) { + if (!table.ReadU8(&b1)) { + return OTS_FAILURE(); + } + result = -(b0 - 251) * 256 + b1 - 108; + } else { + return OTS_FAILURE(); + } + + operands.push_back(std::make_pair(result, DICT_OPERAND_INTEGER)); + return true; +} + +bool ParseDictDataReadNext(ots::Buffer &table, + std::vector<Operand> &operands) { + uint8_t op = 0; + if (!table.ReadU8(&op)) { + return OTS_FAILURE(); + } + if (op <= 24) { + if (op == 12) { + return ParseDictDataEscapedOperator(table, operands); + } + operands.push_back(std::make_pair( + static_cast<uint32_t>(op), DICT_OPERATOR)); + return true; + } else if (op <= 27 || op == 31 || op == 255) { + // reserved area. + return OTS_FAILURE(); + } + + return ParseDictDataNumber(table, op, operands); +} + +bool OperandsOverflow(std::vector<Operand>& operands, bool cff2) { + // An operator may be preceded by up to a maximum of 48 operands in CFF1 and + // 513 operands in CFF2. + if ((cff2 && operands.size() > ots::kMaxCFF2ArgumentStack) || + (!cff2 && operands.size() > ots::kMaxCFF1ArgumentStack)) { + return true; + } + return false; +} + +bool ParseDictDataReadOperands(ots::Buffer& dict, + std::vector<Operand>& operands, + bool cff2) { + if (!ParseDictDataReadNext(dict, operands)) { + return OTS_FAILURE(); + } + if (operands.empty()) { + return OTS_FAILURE(); + } + if (OperandsOverflow(operands, cff2)) { + return OTS_FAILURE(); + } + return true; +} + +bool ValidCFF2DictOp(uint32_t op, DICT_DATA_TYPE type) { + if (type == DICT_DATA_TOPLEVEL) { + switch (op) { + case (12U << 8) + 7: // FontMatrix + case 17: // CharStrings + case (12U << 8) + 36: // FDArray + case (12U << 8) + 37: // FDSelect + case 24: // vstore + return true; + default: + return false; + } + } else if (type == DICT_DATA_FDARRAY) { + if (op == 18) // Private DICT + return true; + } else if (type == DICT_DATA_PRIVATE) { + switch (op) { + case (12U << 8) + 14: // ForceBold + case (12U << 8) + 19: // initialRandomSeed + case 20: // defaultWidthX + case 21: // nominalWidthX + return false; + default: + return true; + } + } + + return false; +} + +bool ParsePrivateDictData( + ots::Buffer &table, size_t offset, size_t dict_length, + DICT_DATA_TYPE type, ots::OpenTypeCFF *out_cff) { + ots::Buffer dict(table.buffer() + offset, dict_length); + std::vector<Operand> operands; + bool cff2 = (out_cff->major == 2); + bool blend_seen = false; + int32_t vsindex = 0; + + // Since a Private DICT for FDArray might not have a Local Subr (e.g. Hiragino + // Kaku Gothic Std W8), we create an empty Local Subr here to match the size + // of FDArray the size of |local_subrs_per_font|. + // For CFF2, |vsindex_per_font| gets a similar treatment. + if (type == DICT_DATA_FDARRAY) { + out_cff->local_subrs_per_font.push_back(new ots::CFFIndex); + if (cff2) { + out_cff->vsindex_per_font.push_back(vsindex); + } + } + + while (dict.offset() < dict.length()) { + if (!ParseDictDataReadOperands(dict, operands, cff2)) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERATOR) { + continue; + } + + // got operator + const uint32_t op = operands.back().first; + operands.pop_back(); + + if (cff2 && !ValidCFF2DictOp(op, DICT_DATA_PRIVATE)) { + return OTS_FAILURE(); + } + + bool clear_operands = true; + switch (op) { + // hints + case 6: // BlueValues + case 7: // OtherBlues + case 8: // FamilyBlues + case 9: // FamilyOtherBlues + if ((operands.size() % 2) != 0) { + return OTS_FAILURE(); + } + break; + + // array + case (12U << 8) + 12: // StemSnapH (delta) + case (12U << 8) + 13: // StemSnapV (delta) + if (operands.empty()) { + return OTS_FAILURE(); + } + break; + + // number + case 10: // StdHW + case 11: // StdVW + case 20: // defaultWidthX + case 21: // nominalWidthX + case (12U << 8) + 9: // BlueScale + case (12U << 8) + 10: // BlueShift + case (12U << 8) + 11: // BlueFuzz + case (12U << 8) + 17: // LanguageGroup + case (12U << 8) + 18: // ExpansionFactor + case (12U << 8) + 19: // initialRandomSeed + if (operands.size() != 1) { + return OTS_FAILURE(); + } + break; + + // Local Subrs INDEX, offset(self) + case 19: { + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (operands.back().first >= 1024 * 1024 * 1024) { + return OTS_FAILURE(); + } + if (operands.back().first + offset >= table.length()) { + return OTS_FAILURE(); + } + // parse "16. Local Subrs INDEX" + table.set_offset(operands.back().first + offset); + ots::CFFIndex *local_subrs_index = NULL; + if (type == DICT_DATA_FDARRAY) { + if (out_cff->local_subrs_per_font.empty()) { + return OTS_FAILURE(); // not reached. + } + local_subrs_index = out_cff->local_subrs_per_font.back(); + } else { // type == DICT_DATA_TOPLEVEL + if (out_cff->local_subrs) { + return OTS_FAILURE(); // two or more local_subrs? + } + local_subrs_index = new ots::CFFIndex; + out_cff->local_subrs = local_subrs_index; + } + if (!ParseIndex(table, *local_subrs_index, cff2)) { + return OTS_FAILURE(); + } + break; + } + + // boolean + case (12U << 8) + 14: // ForceBold + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (operands.back().first >= 2) { + return OTS_FAILURE(); + } + break; + + case 22: { // vsindex + if (!cff2) { + return OTS_FAILURE(); + } + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (blend_seen) { + return OTS_FAILURE(); + } + vsindex = operands.back().first; + if (vsindex < 0 || + vsindex >= (int32_t)out_cff->region_index_count.size()) { + return OTS_FAILURE(); + } + out_cff->vsindex_per_font.back() = vsindex; + break; + } + + case 23: { // blend + if (!cff2) { + return OTS_FAILURE(); + } + if (operands.size() < 1) { + return OTS_FAILURE(); + } + if (vsindex >= (int32_t)out_cff->region_index_count.size()) { + return OTS_FAILURE(); + } + uint16_t k = out_cff->region_index_count.at(vsindex); + uint16_t n = operands.back().first; + if (operands.size() < n * (k + 1) + 1) { + return OTS_FAILURE(); + } + size_t operands_size = operands.size(); + // Keep the 1st n operands on the stack for the next operator to use + // and pop the rest. There can be multiple consecutive blend operator, + // so this makes sure the operands of all of them are kept on the + // stack. + while (operands.size() > operands_size - ((n * k) + 1)) + operands.pop_back(); + clear_operands = false; + blend_seen = true; + break; + } + + default: + return OTS_FAILURE(); + } + if (clear_operands) { + operands.clear(); + } + } + + return true; +} + +bool ParseVariationStore(ots::OpenTypeCFF& out_cff, ots::Buffer& table) { + uint16_t length; + + if (!table.ReadU16(&length)) { + return OTS_FAILURE(); + } + + // Empty VariationStore is allowed. + if (!length) { + return true; + } + + if (length > table.remaining()) { + return OTS_FAILURE(); + } + + if (!ParseItemVariationStore(out_cff.GetFont(), + table.buffer() + table.offset(), length, + &(out_cff.region_index_count))) { + return OTS_FAILURE(); + } + + return true; +} + +bool ParseDictData(ots::Buffer& table, ots::Buffer& dict, + uint16_t glyphs, size_t sid_max, DICT_DATA_TYPE type, + ots::OpenTypeCFF *out_cff); + +bool ParseDictData(ots::Buffer& table, const ots::CFFIndex &index, + uint16_t glyphs, size_t sid_max, DICT_DATA_TYPE type, + ots::OpenTypeCFF *out_cff) { + for (unsigned i = 1; i < index.offsets.size(); ++i) { + size_t dict_length = index.offsets[i] - index.offsets[i - 1]; + ots::Buffer dict(table.buffer() + index.offsets[i - 1], dict_length); + + if (!ParseDictData(table, dict, glyphs, sid_max, type, out_cff)) { + return OTS_FAILURE(); + } + } + return true; +} + +bool ParseDictData(ots::Buffer& table, ots::Buffer& dict, + uint16_t glyphs, size_t sid_max, DICT_DATA_TYPE type, + ots::OpenTypeCFF *out_cff) { + bool cff2 = (out_cff->major == 2); + std::vector<Operand> operands; + + FONT_FORMAT font_format = FORMAT_UNKNOWN; + bool have_ros = false; + bool have_charstrings = false; + bool have_vstore = false; + size_t charset_offset = 0; + bool have_private = false; + + if (cff2) { + // Parse VariationStore first, since it might be referenced in other places + // (e.g. FDArray) that might be parsed after it. + size_t dict_offset = dict.offset(); + while (dict.offset() < dict.length()) { + if (!ParseDictDataReadOperands(dict, operands, cff2)) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERATOR) continue; + + // got operator + const uint32_t op = operands.back().first; + operands.pop_back(); + + if (op == 18 && type == DICT_DATA_FDARRAY) { + have_private = true; + } + + if (op == 24) { // vstore + if (type != DICT_DATA_TOPLEVEL) { + return OTS_FAILURE(); + } + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (!CheckOffset(operands.back(), table.length())) { + return OTS_FAILURE(); + } + // parse "VariationStore Data Contents" + table.set_offset(operands.back().first); + if (!ParseVariationStore(*out_cff, table)) { + return OTS_FAILURE(); + } + break; + } + operands.clear(); + } + operands.clear(); + dict.set_offset(dict_offset); + + if (type == DICT_DATA_FDARRAY && !have_private) { + return OTS_FAILURE(); // CFF2 FD must have PrivateDICT entry (even if 0, 0) + } + + } + + while (dict.offset() < dict.length()) { + if (!ParseDictDataReadOperands(dict, operands, cff2)) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERATOR) continue; + + // got operator + const uint32_t op = operands.back().first; + operands.pop_back(); + + if (cff2 && !ValidCFF2DictOp(op, type)) { + return OTS_FAILURE(); + } + + switch (op) { + // SID + case 0: // version + case 1: // Notice + case 2: // Copyright + case 3: // FullName + case 4: // FamilyName + case (12U << 8) + 0: // Copyright + case (12U << 8) + 21: // PostScript + case (12U << 8) + 22: // BaseFontName + case (12U << 8) + 38: // FontName + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (!CheckSid(operands.back(), sid_max)) { + return OTS_FAILURE(); + } + break; + + // array + case 5: // FontBBox + case 14: // XUID + case (12U << 8) + 7: // FontMatrix + case (12U << 8) + 23: // BaseFontBlend (delta) + if (operands.empty()) { + return OTS_FAILURE(); + } + break; + + // number + case 13: // UniqueID + case (12U << 8) + 2: // ItalicAngle + case (12U << 8) + 3: // UnderlinePosition + case (12U << 8) + 4: // UnderlineThickness + case (12U << 8) + 5: // PaintType + case (12U << 8) + 8: // StrokeWidth + case (12U << 8) + 20: // SyntheticBase + if (operands.size() != 1) { + return OTS_FAILURE(); + } + break; + case (12U << 8) + 31: // CIDFontVersion + case (12U << 8) + 32: // CIDFontRevision + case (12U << 8) + 33: // CIDFontType + case (12U << 8) + 34: // CIDCount + case (12U << 8) + 35: // UIDBase + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (font_format != FORMAT_CID_KEYED) { + return OTS_FAILURE(); + } + break; + case (12U << 8) + 6: // CharstringType + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if(operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (operands.back().first != 2) { + // We only support the "Type 2 Charstring Format." + // TODO(yusukes): Support Type 1 format? Is that still in use? + return OTS_FAILURE(); + } + break; + + // boolean + case (12U << 8) + 1: // isFixedPitch + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + if (operands.back().first >= 2) { + return OTS_FAILURE(); + } + break; + + // offset(0) + case 15: // charset + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (operands.back().first <= 2) { + // predefined charset, ISOAdobe, Expert or ExpertSubset, is used. + break; + } + if (!CheckOffset(operands.back(), table.length())) { + return OTS_FAILURE(); + } + if (charset_offset) { + return OTS_FAILURE(); // multiple charset tables? + } + charset_offset = operands.back().first; + break; + + case 16: { // Encoding + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (operands.back().first <= 1) { + break; // predefined encoding, "Standard" or "Expert", is used. + } + if (!CheckOffset(operands.back(), table.length())) { + return OTS_FAILURE(); + } + + table.set_offset(operands.back().first); + uint8_t format = 0; + if (!table.ReadU8(&format)) { + return OTS_FAILURE(); + } + if (format & 0x80) { + // supplemental encoding is not supported at the moment. + return OTS_FAILURE(); + } + // TODO(yusukes): support & parse supplemental encoding tables. + break; + } + + case 17: { // CharStrings + if (type != DICT_DATA_TOPLEVEL) { + return OTS_FAILURE(); + } + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (!CheckOffset(operands.back(), table.length())) { + return OTS_FAILURE(); + } + // parse "14. CharStrings INDEX" + table.set_offset(operands.back().first); + ots::CFFIndex *charstring_index = out_cff->charstrings_index; + if (!ParseIndex(table, *charstring_index, cff2)) { + return OTS_FAILURE(); + } + if (charstring_index->count < 2) { + return OTS_FAILURE(); + } + if (have_charstrings) { + return OTS_FAILURE(); // multiple charstring tables? + } + have_charstrings = true; + if (charstring_index->count != glyphs) { + return OTS_FAILURE(); // CFF and maxp have different number of glyphs? + } + break; + } + + case 24: { // vstore + if (!cff2) { + return OTS_FAILURE(); + } + if (have_vstore) { + return OTS_FAILURE(); // multiple vstore tables? + } + have_vstore = true; + // parsed above. + break; + } + + case (12U << 8) + 36: { // FDArray + if (type != DICT_DATA_TOPLEVEL) { + return OTS_FAILURE(); + } + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (!CheckOffset(operands.back(), table.length())) { + return OTS_FAILURE(); + } + + // parse Font DICT INDEX. + table.set_offset(operands.back().first); + ots::CFFIndex sub_dict_index; + if (!ParseIndex(table, sub_dict_index, cff2)) { + return OTS_FAILURE(); + } + if (!ParseDictData(table, sub_dict_index, + glyphs, sid_max, DICT_DATA_FDARRAY, + out_cff)) { + return OTS_FAILURE(); + } + if (out_cff->font_dict_length != 0) { + return OTS_FAILURE(); // two or more FDArray found. + } + out_cff->font_dict_length = sub_dict_index.count; + break; + } + + case (12U << 8) + 37: { // FDSelect + if (type != DICT_DATA_TOPLEVEL) { + return OTS_FAILURE(); + } + if (operands.size() != 1) { + return OTS_FAILURE(); + } + if (!CheckOffset(operands.back(), table.length())) { + return OTS_FAILURE(); + } + + // parse FDSelect data structure + table.set_offset(operands.back().first); + uint8_t format = 0; + if (!table.ReadU8(&format)) { + return OTS_FAILURE(); + } + if (format == 0) { + for (uint16_t j = 0; j < glyphs; ++j) { + uint8_t fd_index = 0; + if (!table.ReadU8(&fd_index)) { + return OTS_FAILURE(); + } + (out_cff->fd_select)[j] = fd_index; + } + } else if (format == 3) { + uint16_t n_ranges = 0; + if (!table.ReadU16(&n_ranges)) { + return OTS_FAILURE(); + } + if (n_ranges == 0) { + return OTS_FAILURE(); + } + + uint16_t last_gid = 0; + uint8_t fd_index = 0; + for (unsigned j = 0; j < n_ranges; ++j) { + uint16_t first = 0; // GID + if (!table.ReadU16(&first)) { + return OTS_FAILURE(); + } + + // Sanity checks. + if ((j == 0) && (first != 0)) { + return OTS_FAILURE(); + } + if ((j != 0) && (last_gid >= first)) { + return OTS_FAILURE(); // not increasing order. + } + if (first >= glyphs) { + return OTS_FAILURE(); // invalid gid. + } + + // Copy the mapping to |out_cff->fd_select|. + if (j != 0) { + for (auto k = last_gid; k < first; ++k) { + if (!out_cff->fd_select.insert( + std::make_pair(k, fd_index)).second) { + return OTS_FAILURE(); + } + } + } + + if (!table.ReadU8(&fd_index)) { + return OTS_FAILURE(); + } + last_gid = first; + } + uint16_t sentinel = 0; + if (!table.ReadU16(&sentinel)) { + return OTS_FAILURE(); + } + if (last_gid >= sentinel) { + return OTS_FAILURE(); + } + if (sentinel > glyphs) { + return OTS_FAILURE(); // invalid gid. + } + for (auto k = last_gid; k < sentinel; ++k) { + if (!out_cff->fd_select.insert( + std::make_pair(k, fd_index)).second) { + return OTS_FAILURE(); + } + } + } else if (cff2 && format == 4) { + uint32_t n_ranges = 0; + if (!table.ReadU32(&n_ranges)) { + return OTS_FAILURE(); + } + if (n_ranges == 0) { + return OTS_FAILURE(); + } + + uint32_t last_gid = 0; + uint16_t fd_index = 0; + for (unsigned j = 0; j < n_ranges; ++j) { + uint32_t first = 0; // GID + if (!table.ReadU32(&first)) { + return OTS_FAILURE(); + } + + // Sanity checks. + if ((j == 0) && (first != 0)) { + return OTS_FAILURE(); + } + if ((j != 0) && (last_gid >= first)) { + return OTS_FAILURE(); // not increasing order. + } + if (first >= glyphs) { + return OTS_FAILURE(); // invalid gid. + } + + // Copy the mapping to |out_cff->fd_select|. + if (j != 0) { + for (auto k = last_gid; k < first; ++k) { + if (!out_cff->fd_select.insert( + std::make_pair(k, fd_index)).second) { + return OTS_FAILURE(); + } + } + } + + if (!table.ReadU16(&fd_index)) { + return OTS_FAILURE(); + } + last_gid = first; + } + uint32_t sentinel = 0; + if (!table.ReadU32(&sentinel)) { + return OTS_FAILURE(); + } + if (last_gid >= sentinel) { + return OTS_FAILURE(); + } + if (sentinel > glyphs) { + return OTS_FAILURE(); // invalid gid. + } + for (auto k = last_gid; k < sentinel; ++k) { + if (!out_cff->fd_select.insert( + std::make_pair(k, fd_index)).second) { + return OTS_FAILURE(); + } + } + } else { + // unknown format + return OTS_FAILURE(); + } + break; + } + + // Private DICT (2 * number) + case 18: { + if (operands.size() != 2) { + return OTS_FAILURE(); + } + if (operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + const uint32_t private_offset = operands.back().first; + operands.pop_back(); + if (operands.back().second != DICT_OPERAND_INTEGER) { + return OTS_FAILURE(); + } + const uint32_t private_length = operands.back().first; + if (private_offset > table.length()) { + return OTS_FAILURE(); + } + if (private_length >= table.length()) { + return OTS_FAILURE(); + } + if (private_length + private_offset > table.length()) { + return OTS_FAILURE(); + } + // parse "15. Private DICT data" + if (!ParsePrivateDictData(table, private_offset, private_length, + type, out_cff)) { + return OTS_FAILURE(); + } + break; + } + + // ROS + case (12U << 8) + 30: + if (font_format != FORMAT_UNKNOWN) { + return OTS_FAILURE(); + } + font_format = FORMAT_CID_KEYED; + if (operands.size() != 3) { + return OTS_FAILURE(); + } + // check SIDs + operands.pop_back(); // ignore the first number. + if (!CheckSid(operands.back(), sid_max)) { + return OTS_FAILURE(); + } + operands.pop_back(); + if (!CheckSid(operands.back(), sid_max)) { + return OTS_FAILURE(); + } + if (have_ros) { + return OTS_FAILURE(); // multiple ROS tables? + } + have_ros = true; + break; + + default: + return OTS_FAILURE(); + } + operands.clear(); + + if (font_format == FORMAT_UNKNOWN) { + font_format = FORMAT_OTHER; + } + } + + // parse "13. Charsets" + if (charset_offset) { + table.set_offset(charset_offset); + uint8_t format = 0; + if (!table.ReadU8(&format)) { + return OTS_FAILURE(); + } + switch (format) { + case 0: + for (uint16_t j = 1 /* .notdef is omitted */; j < glyphs; ++j) { + uint16_t sid = 0; + if (!table.ReadU16(&sid)) { + return OTS_FAILURE(); + } + if (!have_ros && (sid > sid_max)) { + return OTS_FAILURE(); + } + // TODO(yusukes): check CIDs when have_ros is true. + } + break; + + case 1: + case 2: { + uint32_t total = 1; // .notdef is omitted. + while (total < glyphs) { + uint16_t sid = 0; + if (!table.ReadU16(&sid)) { + return OTS_FAILURE(); + } + if (!have_ros && (sid > sid_max)) { + return OTS_FAILURE(); + } + // TODO(yusukes): check CIDs when have_ros is true. + + if (format == 1) { + uint8_t left = 0; + if (!table.ReadU8(&left)) { + return OTS_FAILURE(); + } + total += (left + 1); + } else { + uint16_t left = 0; + if (!table.ReadU16(&left)) { + return OTS_FAILURE(); + } + total += (left + 1); + } + } + break; + } + + default: + return OTS_FAILURE(); + } + } + return true; +} + +} // namespace + +namespace ots { + +bool OpenTypeCFF::ValidateFDSelect(uint16_t num_glyphs) { + for (const auto& fd_select : this->fd_select) { + if (fd_select.first >= num_glyphs) { + return Error("Invalid glyph index in FDSelect: %d >= %d\n", + fd_select.first, num_glyphs); + } + if (fd_select.second >= this->font_dict_length) { + return Error("Invalid FD index: %d >= %d\n", + fd_select.second, this->font_dict_length); + } + } + return true; +} + +bool OpenTypeCFF::Parse(const uint8_t *data, size_t length) { + Buffer table(data, length); + + Font *font = GetFont(); + + this->m_data = data; + this->m_length = length; + + // parse "6. Header" in the Adobe Compact Font Format Specification + uint8_t major = 0; + uint8_t minor = 0; + uint8_t hdr_size = 0; + uint8_t off_size = 0; + if (!table.ReadU8(&major) || + !table.ReadU8(&minor) || + !table.ReadU8(&hdr_size) || + !table.ReadU8(&off_size)) { + return Error("Failed to read table header"); + } + + if (off_size < 1 || off_size > 4) { + return Error("Bad offSize: %d", off_size); + } + + if (major != 1 || minor != 0) { + return Error("Unsupported table version: %d.%d", major, minor); + } + + this->major = major; + + if (hdr_size != 4 || hdr_size >= length) { + return Error("Bad hdrSize: %d", hdr_size); + } + + // parse "7. Name INDEX" + table.set_offset(hdr_size); + CFFIndex name_index; + if (!ParseIndex(table, name_index)) { + return Error("Failed to parse Name INDEX"); + } + if (name_index.count != 1 || name_index.offsets.size() != 2) { + return Error("Name INDEX must contain only one entry, not %d", + name_index.count); + } + if (!ParseNameData(&table, name_index, &(this->name))) { + return Error("Failed to parse Name INDEX data"); + } + + // parse "8. Top DICT INDEX" + table.set_offset(name_index.offset_to_next); + CFFIndex top_dict_index; + if (!ParseIndex(table, top_dict_index)) { + return Error("Failed to parse Top DICT INDEX"); + } + if (top_dict_index.count != 1) { + return Error("Top DICT INDEX must contain only one entry, not %d", + top_dict_index.count); + } + + // parse "10. String INDEX" + table.set_offset(top_dict_index.offset_to_next); + CFFIndex string_index; + if (!ParseIndex(table, string_index)) { + return Error("Failed to parse String INDEX"); + } + if (string_index.count >= 65000 - kNStdString) { + return Error("Too many entries in String INDEX: %d", string_index.count); + } + + OpenTypeMAXP *maxp = static_cast<OpenTypeMAXP*>( + font->GetTypedTable(OTS_TAG_MAXP)); + if (!maxp) { + return Error("Required maxp table missing"); + } + const uint16_t num_glyphs = maxp->num_glyphs; + const size_t sid_max = string_index.count + kNStdString; + // string_index.count == 0 is allowed. + + // parse "9. Top DICT Data" + this->charstrings_index = new ots::CFFIndex; + if (!ParseDictData(table, top_dict_index, + num_glyphs, sid_max, + DICT_DATA_TOPLEVEL, this)) { + return Error("Failed to parse Top DICT Data"); + } + + // parse "16. Global Subrs INDEX" + table.set_offset(string_index.offset_to_next); + CFFIndex global_subrs_index; + if (!ParseIndex(table, global_subrs_index)) { + return Error("Failed to parse Global Subrs INDEX"); + } + + // Check if all fd and glyph indices in FDSelect are valid. + if (!ValidateFDSelect(num_glyphs)) { + return Error("Failed to validate FDSelect"); + } + + // Check if all charstrings (font hinting code for each glyph) are valid. + if (!ValidateCFFCharStrings(*this, global_subrs_index, &table)) { + return Error("Failed validating CharStrings INDEX"); + } + + return true; +} + +bool OpenTypeCFF::Serialize(OTSStream *out) { + if (!out->Write(this->m_data, this->m_length)) { + return Error("Failed to write table"); + } + return true; +} + +OpenTypeCFF::~OpenTypeCFF() { + for (size_t i = 0; i < this->local_subrs_per_font.size(); ++i) { + delete (this->local_subrs_per_font)[i]; + } + delete this->charstrings_index; + delete this->local_subrs; +} + +bool OpenTypeCFF2::Parse(const uint8_t *data, size_t length) { + Buffer table(data, length); + + Font *font = GetFont(); + + this->m_data = data; + this->m_length = length; + + // parse "6. Header" + uint8_t major = 0; + uint8_t minor = 0; + uint8_t hdr_size = 0; + uint16_t top_dict_size = 0; + if (!table.ReadU8(&major) || + !table.ReadU8(&minor) || + !table.ReadU8(&hdr_size) || + !table.ReadU16(&top_dict_size)) { + return Error("Failed to read table header"); + } + + if (major != 2 || minor != 0) { + return Error("Unsupported table version: %d.%d", major, minor); + } + + this->major = major; + + if (hdr_size >= length) { + return Error("Bad hdrSize: %d", hdr_size); + } + + if (top_dict_size == 0 || hdr_size + top_dict_size > length) { + return Error("Bad topDictLength: %d", top_dict_size); + } + + OpenTypeMAXP *maxp = static_cast<OpenTypeMAXP*>( + font->GetTypedTable(OTS_TAG_MAXP)); + if (!maxp) { + return Error("Required maxp table missing"); + } + const uint16_t num_glyphs = maxp->num_glyphs; + const size_t sid_max = kNStdString; + + // parse "7. Top DICT Data" + ots::Buffer top_dict(data + hdr_size, top_dict_size); + table.set_offset(hdr_size); + this->charstrings_index = new ots::CFFIndex; + if (!ParseDictData(table, top_dict, + num_glyphs, sid_max, + DICT_DATA_TOPLEVEL, this)) { + return Error("Failed to parse Top DICT Data"); + } + + // parse "9. Global Subrs INDEX" + table.set_offset(hdr_size + top_dict_size); + CFFIndex global_subrs_index; + if (!ParseIndex(table, global_subrs_index, true)) { + return Error("Failed to parse Global Subrs INDEX"); + } + + // Check if all fd and glyph indices in FDSelect are valid. + if (!ValidateFDSelect(num_glyphs)) { + return Error("Failed to validate FDSelect"); + } + + // Check if all charstrings (font hinting code for each glyph) are valid. + if (!ValidateCFFCharStrings(*this, global_subrs_index, &table)) { + return Error("Failed validating CharStrings INDEX"); + } + + return true; +} + +bool OpenTypeCFF2::Serialize(OTSStream *out) { + if (!out->Write(this->m_data, this->m_length)) { + return Error("Failed to write table"); + } + return true; +} + +} // namespace ots + +#undef TABLE_NAME |