1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "cff.h" 6 7 #include <cstring> 8 #include <utility> // std::pair 9 #include <vector> 10 11 #include "cff_type2_charstring.h" 12 13 // CFF - PostScript font program (Compact Font Format) table 14 // http://www.microsoft.com/typography/otspec/cff.htm 15 // http://www.microsoft.com/typography/otspec/cffspec.htm 16 17 namespace { 18 19 enum DICT_OPERAND_TYPE { 20 DICT_OPERAND_INTEGER, 21 DICT_OPERAND_REAL, 22 DICT_OPERATOR, 23 }; 24 25 enum DICT_DATA_TYPE { 26 DICT_DATA_TOPLEVEL, 27 DICT_DATA_FDARRAY, 28 }; 29 30 enum FONT_FORMAT { 31 FORMAT_UNKNOWN, 32 FORMAT_CID_KEYED, 33 FORMAT_OTHER, // Including synthetic fonts 34 }; 35 36 // see Appendix. A 37 const size_t kNStdString = 390; 38 39 bool ReadOffset(ots::Buffer *table, uint8_t off_size, uint32_t *offset) { 40 if (off_size > 4) { 41 return OTS_FAILURE(); 42 } 43 44 uint32_t tmp32 = 0; 45 for (unsigned i = 0; i < off_size; ++i) { 46 uint8_t tmp8 = 0; 47 if (!table->ReadU8(&tmp8)) { 48 return OTS_FAILURE(); 49 } 50 tmp32 <<= 8; 51 tmp32 += tmp8; 52 } 53 *offset = tmp32; 54 return true; 55 } 56 57 bool ParseIndex(ots::Buffer *table, ots::CFFIndex *index) { 58 index->off_size = 0; 59 index->offsets.clear(); 60 61 if (!table->ReadU16(&(index->count))) { 62 return OTS_FAILURE(); 63 } 64 if (index->count == 0) { 65 // An empty INDEX. 66 index->offset_to_next = table->offset(); 67 return true; 68 } 69 70 if (!table->ReadU8(&(index->off_size))) { 71 return OTS_FAILURE(); 72 } 73 if ((index->off_size == 0) || 74 (index->off_size > 4)) { 75 return OTS_FAILURE(); 76 } 77 78 const size_t array_size = (index->count + 1) * index->off_size; 79 // less than ((64k + 1) * 4), thus does not overflow. 80 const size_t object_data_offset = table->offset() + array_size; 81 // does not overflow too, since offset() <= 1GB. 82 83 if (object_data_offset >= table->length()) { 84 return OTS_FAILURE(); 85 } 86 87 for (unsigned i = 0; i <= index->count; ++i) { // '<=' is not a typo. 88 uint32_t rel_offset = 0; 89 if (!ReadOffset(table, index->off_size, &rel_offset)) { 90 return OTS_FAILURE(); 91 } 92 if (rel_offset < 1) { 93 return OTS_FAILURE(); 94 } 95 if (i == 0 && rel_offset != 1) { 96 return OTS_FAILURE(); 97 } 98 99 if (rel_offset > table->length()) { 100 return OTS_FAILURE(); 101 } 102 103 // does not underflow. 104 if (object_data_offset > table->length() - (rel_offset - 1)) { 105 return OTS_FAILURE(); 106 } 107 108 index->offsets.push_back( 109 object_data_offset + (rel_offset - 1)); // less than length(), 1GB. 110 } 111 112 for (unsigned i = 1; i < index->offsets.size(); ++i) { 113 // We allow consecutive identical offsets here for zero-length strings. 114 // See http://crbug.com/69341 for more details. 115 if (index->offsets[i] < index->offsets[i - 1]) { 116 return OTS_FAILURE(); 117 } 118 } 119 120 index->offset_to_next = index->offsets.back(); 121 return true; 122 } 123 124 bool ParseNameData( 125 ots::Buffer *table, const ots::CFFIndex &index, std::string* out_name) { 126 uint8_t name[256] = {0}; 127 if (index.offsets.size() == 0) { // just in case. 128 return OTS_FAILURE(); 129 } 130 for (unsigned i = 1; i < index.offsets.size(); ++i) { 131 const size_t length = index.offsets[i] - index.offsets[i - 1]; 132 // font names should be no longer than 127 characters. 133 if (length > 127) { 134 return OTS_FAILURE(); 135 } 136 137 table->set_offset(index.offsets[i - 1]); 138 if (!table->Read(name, length)) { 139 return OTS_FAILURE(); 140 } 141 142 for (size_t j = 0; j < length; ++j) { 143 // setting the first byte to NUL is allowed. 144 if (j == 0 && name[j] == 0) continue; 145 // non-ASCII characters are not recommended (except the first character). 146 if (name[j] < 33 || name[j] > 126) { 147 return OTS_FAILURE(); 148 } 149 // [, ], ... are not allowed. 150 if (std::strchr("[](){}<>/% ", name[j])) { 151 return OTS_FAILURE(); 152 } 153 } 154 } 155 156 *out_name = reinterpret_cast<char *>(name); 157 return true; 158 } 159 160 bool CheckOffset(const std::pair<uint32_t, DICT_OPERAND_TYPE>& operand, 161 size_t table_length) { 162 if (operand.second != DICT_OPERAND_INTEGER) { 163 return OTS_FAILURE(); 164 } 165 if (operand.first >= table_length) { 166 return OTS_FAILURE(); 167 } 168 return true; 169 } 170 171 bool CheckSid(const std::pair<uint32_t, DICT_OPERAND_TYPE>& operand, 172 size_t sid_max) { 173 if (operand.second != DICT_OPERAND_INTEGER) { 174 return OTS_FAILURE(); 175 } 176 if (operand.first > sid_max) { 177 return OTS_FAILURE(); 178 } 179 return true; 180 } 181 182 bool ParseDictDataBcd( 183 ots::Buffer *table, 184 std::vector<std::pair<uint32_t, DICT_OPERAND_TYPE> > *operands) { 185 bool read_decimal_point = false; 186 bool read_e = false; 187 188 uint8_t nibble = 0; 189 size_t count = 0; 190 while (true) { 191 if (!table->ReadU8(&nibble)) { 192 return OTS_FAILURE(); 193 } 194 if ((nibble & 0xf0) == 0xf0) { 195 if ((nibble & 0xf) == 0xf) { 196 // TODO(yusukes): would be better to store actual double value, 197 // rather than the dummy integer. 198 operands->push_back(std::make_pair(static_cast<uint32_t>(0), 199 DICT_OPERAND_REAL)); 200 return true; 201 } 202 return OTS_FAILURE(); 203 } 204 if ((nibble & 0x0f) == 0x0f) { 205 operands->push_back(std::make_pair(static_cast<uint32_t>(0), 206 DICT_OPERAND_REAL)); 207 return true; 208 } 209 210 // check number format 211 uint8_t nibbles[2]; 212 nibbles[0] = (nibble & 0xf0) >> 8; 213 nibbles[1] = (nibble & 0x0f); 214 for (unsigned i = 0; i < 2; ++i) { 215 if (nibbles[i] == 0xd) { // reserved number 216 return OTS_FAILURE(); 217 } 218 if ((nibbles[i] == 0xe) && // minus 219 ((count > 0) || (i > 0))) { 220 return OTS_FAILURE(); // minus sign should be the first character. 221 } 222 if (nibbles[i] == 0xa) { // decimal point 223 if (!read_decimal_point) { 224 read_decimal_point = true; 225 } else { 226 return OTS_FAILURE(); // two or more points. 227 } 228 } 229 if ((nibbles[i] == 0xb) || // E+ 230 (nibbles[i] == 0xc)) { // E- 231 if (!read_e) { 232 read_e = true; 233 } else { 234 return OTS_FAILURE(); // two or more E's. 235 } 236 } 237 } 238 ++count; 239 } 240 } 241 242 bool ParseDictDataEscapedOperator( 243 ots::Buffer *table, 244 std::vector<std::pair<uint32_t, DICT_OPERAND_TYPE> > *operands) { 245 uint8_t op = 0; 246 if (!table->ReadU8(&op)) { 247 return OTS_FAILURE(); 248 } 249 250 if ((op <= 14) || 251 (op >= 17 && op <= 23) || 252 (op >= 30 && op <= 38)) { 253 operands->push_back(std::make_pair((12U << 8) + op, DICT_OPERATOR)); 254 return true; 255 } 256 257 // reserved area. 258 return OTS_FAILURE(); 259 } 260 261 bool ParseDictDataNumber( 262 ots::Buffer *table, uint8_t b0, 263 std::vector<std::pair<uint32_t, DICT_OPERAND_TYPE> > *operands) { 264 uint8_t b1 = 0; 265 uint8_t b2 = 0; 266 uint8_t b3 = 0; 267 uint8_t b4 = 0; 268 269 switch (b0) { 270 case 28: // shortint 271 if (!table->ReadU8(&b1) || 272 !table->ReadU8(&b2)) { 273 return OTS_FAILURE(); 274 } 275 operands->push_back(std::make_pair( 276 static_cast<uint32_t>((b1 << 8) + b2), DICT_OPERAND_INTEGER)); 277 return true; 278 279 case 29: // longint 280 if (!table->ReadU8(&b1) || 281 !table->ReadU8(&b2) || 282 !table->ReadU8(&b3) || 283 !table->ReadU8(&b4)) { 284 return OTS_FAILURE(); 285 } 286 operands->push_back(std::make_pair( 287 static_cast<uint32_t>((b1 << 24) + (b2 << 16) + (b3 << 8) + b4), 288 DICT_OPERAND_INTEGER)); 289 return true; 290 291 case 30: // binary coded decimal 292 return ParseDictDataBcd(table, operands); 293 294 default: 295 break; 296 } 297 298 uint32_t result; 299 if (b0 >=32 && b0 <=246) { 300 result = b0 - 139; 301 } else if (b0 >=247 && b0 <= 250) { 302 if (!table->ReadU8(&b1)) { 303 return OTS_FAILURE(); 304 } 305 result = (b0 - 247) * 256 + b1 + 108; 306 } else if (b0 >= 251 && b0 <= 254) { 307 if (!table->ReadU8(&b1)) { 308 return OTS_FAILURE(); 309 } 310 result = -(b0 - 251) * 256 + b1 - 108; 311 } else { 312 return OTS_FAILURE(); 313 } 314 315 operands->push_back(std::make_pair(result, DICT_OPERAND_INTEGER)); 316 return true; 317 } 318 319 bool ParseDictDataReadNext( 320 ots::Buffer *table, 321 std::vector<std::pair<uint32_t, DICT_OPERAND_TYPE> > *operands) { 322 uint8_t op = 0; 323 if (!table->ReadU8(&op)) { 324 return OTS_FAILURE(); 325 } 326 if (op <= 21) { 327 if (op == 12) { 328 return ParseDictDataEscapedOperator(table, operands); 329 } 330 operands->push_back(std::make_pair( 331 static_cast<uint32_t>(op), DICT_OPERATOR)); 332 return true; 333 } else if (op <= 27 || op == 31 || op == 255) { 334 // reserved area. 335 return OTS_FAILURE(); 336 } 337 338 return ParseDictDataNumber(table, op, operands); 339 } 340 341 bool ParsePrivateDictData( 342 const uint8_t *data, 343 size_t table_length, size_t offset, size_t dict_length, 344 DICT_DATA_TYPE type, ots::OpenTypeCFF *out_cff) { 345 ots::Buffer table(data + offset, dict_length); 346 std::vector<std::pair<uint32_t, DICT_OPERAND_TYPE> > operands; 347 348 // Since a Private DICT for FDArray might not have a Local Subr (e.g. Hiragino 349 // Kaku Gothic Std W8), we create an empty Local Subr here to match the size 350 // of FDArray the size of |local_subrs_per_font|. 351 if (type == DICT_DATA_FDARRAY) { 352 out_cff->local_subrs_per_font.push_back(new ots::CFFIndex); 353 } 354 355 while (table.offset() < dict_length) { 356 if (!ParseDictDataReadNext(&table, &operands)) { 357 return OTS_FAILURE(); 358 } 359 if (operands.empty()) { 360 return OTS_FAILURE(); 361 } 362 if (operands.size() > 48) { 363 // An operator may be preceded by up to a maximum of 48 operands. 364 return OTS_FAILURE(); 365 } 366 if (operands.back().second != DICT_OPERATOR) { 367 continue; 368 } 369 370 // got operator 371 const uint32_t op = operands.back().first; 372 operands.pop_back(); 373 374 switch (op) { 375 // array 376 case 6: // BlueValues 377 case 7: // OtherBlues 378 case 8: // FamilyBlues 379 case 9: // FamilyOtherBlues 380 case (12U << 8) + 12: // StemSnapH (delta) 381 case (12U << 8) + 13: // StemSnapV (delta) 382 if (operands.empty()) { 383 return OTS_FAILURE(); 384 } 385 break; 386 387 // number 388 case 10: // StdHW 389 case 11: // StdVW 390 case 20: // defaultWidthX 391 case 21: // nominalWidthX 392 case (12U << 8) + 9: // BlueScale 393 case (12U << 8) + 10: // BlueShift 394 case (12U << 8) + 11: // BlueFuzz 395 case (12U << 8) + 17: // LanguageGroup 396 case (12U << 8) + 18: // ExpansionFactor 397 case (12U << 8) + 19: // initialRandomSeed 398 if (operands.size() != 1) { 399 return OTS_FAILURE(); 400 } 401 break; 402 403 // Local Subrs INDEX, offset(self) 404 case 19: { 405 if (operands.size() != 1) { 406 return OTS_FAILURE(); 407 } 408 if (operands.back().second != DICT_OPERAND_INTEGER) { 409 return OTS_FAILURE(); 410 } 411 if (operands.back().first >= 1024 * 1024 * 1024) { 412 return OTS_FAILURE(); 413 } 414 if (operands.back().first + offset >= table_length) { 415 return OTS_FAILURE(); 416 } 417 // parse "16. Local Subrs INDEX" 418 ots::Buffer table(data, table_length); 419 table.set_offset(operands.back().first + offset); 420 ots::CFFIndex *local_subrs_index = NULL; 421 if (type == DICT_DATA_FDARRAY) { 422 if (out_cff->local_subrs_per_font.empty()) { 423 return OTS_FAILURE(); // not reached. 424 } 425 local_subrs_index = out_cff->local_subrs_per_font.back(); 426 } else { // type == DICT_DATA_TOPLEVEL 427 if (out_cff->local_subrs) { 428 return OTS_FAILURE(); // two or more local_subrs? 429 } 430 local_subrs_index = new ots::CFFIndex; 431 out_cff->local_subrs = local_subrs_index; 432 } 433 if (!ParseIndex(&table, local_subrs_index)) { 434 return OTS_FAILURE(); 435 } 436 break; 437 } 438 439 // boolean 440 case (12U << 8) + 14: // ForceBold 441 if (operands.size() != 1) { 442 return OTS_FAILURE(); 443 } 444 if (operands.back().second != DICT_OPERAND_INTEGER) { 445 return OTS_FAILURE(); 446 } 447 if (operands.back().first >= 2) { 448 return OTS_FAILURE(); 449 } 450 break; 451 452 default: 453 return OTS_FAILURE(); 454 } 455 operands.clear(); 456 } 457 458 return true; 459 } 460 461 bool ParseDictData(const uint8_t *data, size_t table_length, 462 const ots::CFFIndex &index, size_t sid_max, 463 DICT_DATA_TYPE type, ots::OpenTypeCFF *out_cff) { 464 for (unsigned i = 1; i < index.offsets.size(); ++i) { 465 if (type == DICT_DATA_TOPLEVEL) { 466 out_cff->char_strings_array.push_back(new ots::CFFIndex); 467 } 468 size_t dict_length = index.offsets[i] - index.offsets[i - 1]; 469 ots::Buffer table(data + index.offsets[i - 1], dict_length); 470 471 std::vector<std::pair<uint32_t, DICT_OPERAND_TYPE> > operands; 472 473 FONT_FORMAT font_format = FORMAT_UNKNOWN; 474 bool have_ros = false; 475 size_t glyphs = 0; 476 size_t charset_offset = 0; 477 478 while (table.offset() < dict_length) { 479 if (!ParseDictDataReadNext(&table, &operands)) { 480 return OTS_FAILURE(); 481 } 482 if (operands.empty()) { 483 return OTS_FAILURE(); 484 } 485 if (operands.size() > 48) { 486 // An operator may be preceded by up to a maximum of 48 operands. 487 return OTS_FAILURE(); 488 } 489 if (operands.back().second != DICT_OPERATOR) continue; 490 491 // got operator 492 const uint32_t op = operands.back().first; 493 operands.pop_back(); 494 495 switch (op) { 496 // SID 497 case 0: // version 498 case 1: // Notice 499 case 2: // Copyright 500 case 3: // FullName 501 case 4: // FamilyName 502 case (12U << 8) + 0: // Copyright 503 case (12U << 8) + 21: // PostScript 504 case (12U << 8) + 22: // BaseFontName 505 case (12U << 8) + 38: // FontName 506 if (operands.size() != 1) { 507 return OTS_FAILURE(); 508 } 509 if (!CheckSid(operands.back(), sid_max)) { 510 return OTS_FAILURE(); 511 } 512 break; 513 514 // array 515 case 5: // FontBBox 516 case 14: // XUID 517 case (12U << 8) + 7: // FontMatrix 518 case (12U << 8) + 23: // BaseFontBlend (delta) 519 if (operands.empty()) { 520 return OTS_FAILURE(); 521 } 522 break; 523 524 // number 525 case 13: // UniqueID 526 case (12U << 8) + 2: // ItalicAngle 527 case (12U << 8) + 3: // UnderlinePosition 528 case (12U << 8) + 4: // UnderlineThickness 529 case (12U << 8) + 5: // PaintType 530 case (12U << 8) + 8: // StrokeWidth 531 case (12U << 8) + 20: // SyntheticBase 532 if (operands.size() != 1) { 533 return OTS_FAILURE(); 534 } 535 break; 536 case (12U << 8) + 31: // CIDFontVersion 537 case (12U << 8) + 32: // CIDFontRevision 538 case (12U << 8) + 33: // CIDFontType 539 case (12U << 8) + 34: // CIDCount 540 case (12U << 8) + 35: // UIDBase 541 if (operands.size() != 1) { 542 return OTS_FAILURE(); 543 } 544 if (font_format != FORMAT_CID_KEYED) { 545 return OTS_FAILURE(); 546 } 547 break; 548 case (12U << 8) + 6: // CharstringType 549 if (operands.size() != 1) { 550 return OTS_FAILURE(); 551 } 552 if(operands.back().second != DICT_OPERAND_INTEGER) { 553 return OTS_FAILURE(); 554 } 555 if (operands.back().first != 2) { 556 // We only support the "Type 2 Charstring Format." 557 // TODO(yusukes): Support Type 1 format? Is that still in use? 558 return OTS_FAILURE(); 559 } 560 break; 561 562 // boolean 563 case (12U << 8) + 1: // isFixedPitch 564 if (operands.size() != 1) { 565 return OTS_FAILURE(); 566 } 567 if (operands.back().second != DICT_OPERAND_INTEGER) { 568 return OTS_FAILURE(); 569 } 570 if (operands.back().first >= 2) { 571 return OTS_FAILURE(); 572 } 573 break; 574 575 // offset(0) 576 case 15: // charset 577 if (operands.size() != 1) { 578 return OTS_FAILURE(); 579 } 580 if (operands.back().first <= 2) { 581 // predefined charset, ISOAdobe, Expert or ExpertSubset, is used. 582 break; 583 } 584 if (!CheckOffset(operands.back(), table_length)) { 585 return OTS_FAILURE(); 586 } 587 if (charset_offset) { 588 return OTS_FAILURE(); // multiple charset tables? 589 } 590 charset_offset = operands.back().first; 591 break; 592 593 case 16: { // Encoding 594 if (operands.size() != 1) { 595 return OTS_FAILURE(); 596 } 597 if (operands.back().first <= 1) { 598 break; // predefined encoding, "Standard" or "Expert", is used. 599 } 600 if (!CheckOffset(operands.back(), table_length)) { 601 return OTS_FAILURE(); 602 } 603 604 // parse sub dictionary INDEX. 605 ots::Buffer table(data, table_length); 606 table.set_offset(operands.back().first); 607 uint8_t format = 0; 608 if (!table.ReadU8(&format)) { 609 return OTS_FAILURE(); 610 } 611 if (format & 0x80) { 612 // supplemental encoding is not supported at the moment. 613 return OTS_FAILURE(); 614 } 615 // TODO(yusukes): support & parse supplemental encoding tables. 616 break; 617 } 618 619 case 17: { // CharStrings 620 if (type != DICT_DATA_TOPLEVEL) { 621 return OTS_FAILURE(); 622 } 623 if (operands.size() != 1) { 624 return OTS_FAILURE(); 625 } 626 if (!CheckOffset(operands.back(), table_length)) { 627 return OTS_FAILURE(); 628 } 629 // parse "14. CharStrings INDEX" 630 ots::Buffer table(data, table_length); 631 table.set_offset(operands.back().first); 632 ots::CFFIndex *charstring_index = out_cff->char_strings_array.back(); 633 if (!ParseIndex(&table, charstring_index)) { 634 return OTS_FAILURE(); 635 } 636 if (charstring_index->count < 2) { 637 return OTS_FAILURE(); 638 } 639 if (glyphs) { 640 return OTS_FAILURE(); // multiple charstring tables? 641 } 642 glyphs = charstring_index->count; 643 break; 644 } 645 646 case (12U << 8) + 36: { // FDArray 647 if (type != DICT_DATA_TOPLEVEL) { 648 return OTS_FAILURE(); 649 } 650 if (operands.size() != 1) { 651 return OTS_FAILURE(); 652 } 653 if (!CheckOffset(operands.back(), table_length)) { 654 return OTS_FAILURE(); 655 } 656 657 // parse sub dictionary INDEX. 658 ots::Buffer table(data, table_length); 659 table.set_offset(operands.back().first); 660 ots::CFFIndex sub_dict_index; 661 if (!ParseIndex(&table, &sub_dict_index)) { 662 return OTS_FAILURE(); 663 } 664 if (!ParseDictData(data, table_length, 665 sub_dict_index, sid_max, DICT_DATA_FDARRAY, 666 out_cff)) { 667 return OTS_FAILURE(); 668 } 669 if (out_cff->font_dict_length != 0) { 670 return OTS_FAILURE(); // two or more FDArray found. 671 } 672 out_cff->font_dict_length = sub_dict_index.count; 673 break; 674 } 675 676 case (12U << 8) + 37: { // FDSelect 677 if (type != DICT_DATA_TOPLEVEL) { 678 return OTS_FAILURE(); 679 } 680 if (operands.size() != 1) { 681 return OTS_FAILURE(); 682 } 683 if (!CheckOffset(operands.back(), table_length)) { 684 return OTS_FAILURE(); 685 } 686 687 // parse FDSelect data structure 688 ots::Buffer table(data, table_length); 689 table.set_offset(operands.back().first); 690 uint8_t format = 0; 691 if (!table.ReadU8(&format)) { 692 return OTS_FAILURE(); 693 } 694 if (format == 0) { 695 for (size_t j = 0; j < glyphs; ++j) { 696 uint8_t fd_index = 0; 697 if (!table.ReadU8(&fd_index)) { 698 return OTS_FAILURE(); 699 } 700 (out_cff->fd_select)[j] = fd_index; 701 } 702 } else if (format == 3) { 703 uint16_t n_ranges = 0; 704 if (!table.ReadU16(&n_ranges)) { 705 return OTS_FAILURE(); 706 } 707 if (n_ranges == 0) { 708 return OTS_FAILURE(); 709 } 710 711 uint16_t last_gid = 0; 712 uint8_t fd_index = 0; 713 for (unsigned j = 0; j < n_ranges; ++j) { 714 uint16_t first = 0; // GID 715 if (!table.ReadU16(&first)) { 716 return OTS_FAILURE(); 717 } 718 719 // Sanity checks. 720 if ((j == 0) && (first != 0)) { 721 return OTS_FAILURE(); 722 } 723 if ((j != 0) && (last_gid >= first)) { 724 return OTS_FAILURE(); // not increasing order. 725 } 726 727 // Copy the mapping to |out_cff->fd_select|. 728 if (j != 0) { 729 for (uint16_t k = last_gid; k < first; ++k) { 730 if (!out_cff->fd_select.insert( 731 std::make_pair(k, fd_index)).second) { 732 return OTS_FAILURE(); 733 } 734 } 735 } 736 737 if (!table.ReadU8(&fd_index)) { 738 return OTS_FAILURE(); 739 } 740 last_gid = first; 741 // TODO(yusukes): check GID? 742 } 743 uint16_t sentinel = 0; 744 if (!table.ReadU16(&sentinel)) { 745 return OTS_FAILURE(); 746 } 747 if (last_gid >= sentinel) { 748 return OTS_FAILURE(); 749 } 750 for (uint16_t k = last_gid; k < sentinel; ++k) { 751 if (!out_cff->fd_select.insert( 752 std::make_pair(k, fd_index)).second) { 753 return OTS_FAILURE(); 754 } 755 } 756 } else { 757 // unknown format 758 return OTS_FAILURE(); 759 } 760 break; 761 } 762 763 // Private DICT (2 * number) 764 case 18: { 765 if (operands.size() != 2) { 766 return OTS_FAILURE(); 767 } 768 if (operands.back().second != DICT_OPERAND_INTEGER) { 769 return OTS_FAILURE(); 770 } 771 const uint32_t private_offset = operands.back().first; 772 operands.pop_back(); 773 if (operands.back().second != DICT_OPERAND_INTEGER) { 774 return OTS_FAILURE(); 775 } 776 const uint32_t private_length = operands.back().first; 777 if (private_offset > table_length) { 778 return OTS_FAILURE(); 779 } 780 if (private_length >= table_length) { 781 return OTS_FAILURE(); 782 } 783 if (private_length + private_offset > table_length) { 784 return OTS_FAILURE(); 785 } 786 // parse "15. Private DICT Data" 787 if (!ParsePrivateDictData(data, table_length, 788 private_offset, private_length, 789 type, out_cff)) { 790 return OTS_FAILURE(); 791 } 792 break; 793 } 794 795 // ROS 796 case (12U << 8) + 30: 797 if (font_format != FORMAT_UNKNOWN) { 798 return OTS_FAILURE(); 799 } 800 font_format = FORMAT_CID_KEYED; 801 if (operands.size() != 3) { 802 return OTS_FAILURE(); 803 } 804 // check SIDs 805 operands.pop_back(); // ignore the first number. 806 if (!CheckSid(operands.back(), sid_max)) { 807 return OTS_FAILURE(); 808 } 809 operands.pop_back(); 810 if (!CheckSid(operands.back(), sid_max)) { 811 return OTS_FAILURE(); 812 } 813 if (have_ros) { 814 return OTS_FAILURE(); // multiple ROS tables? 815 } 816 have_ros = true; 817 break; 818 819 default: 820 return OTS_FAILURE(); 821 } 822 operands.clear(); 823 824 if (font_format == FORMAT_UNKNOWN) { 825 font_format = FORMAT_OTHER; 826 } 827 } 828 829 // parse "13. Charsets" 830 if (charset_offset) { 831 ots::Buffer table(data, table_length); 832 table.set_offset(charset_offset); 833 uint8_t format = 0; 834 if (!table.ReadU8(&format)) { 835 return OTS_FAILURE(); 836 } 837 switch (format) { 838 case 0: 839 for (unsigned j = 1 /* .notdef is omitted */; j < glyphs; ++j) { 840 uint16_t sid = 0; 841 if (!table.ReadU16(&sid)) { 842 return OTS_FAILURE(); 843 } 844 if (!have_ros && (sid > sid_max)) { 845 return OTS_FAILURE(); 846 } 847 // TODO(yusukes): check CIDs when have_ros is true. 848 } 849 break; 850 851 case 1: 852 case 2: { 853 uint32_t total = 1; // .notdef is omitted. 854 while (total < glyphs) { 855 uint16_t sid = 0; 856 if (!table.ReadU16(&sid)) { 857 return OTS_FAILURE(); 858 } 859 if (!have_ros && (sid > sid_max)) { 860 return OTS_FAILURE(); 861 } 862 // TODO(yusukes): check CIDs when have_ros is true. 863 864 if (format == 1) { 865 uint8_t left = 0; 866 if (!table.ReadU8(&left)) { 867 return OTS_FAILURE(); 868 } 869 total += (left + 1); 870 } else { 871 uint16_t left = 0; 872 if (!table.ReadU16(&left)) { 873 return OTS_FAILURE(); 874 } 875 total += (left + 1); 876 } 877 } 878 break; 879 } 880 881 default: 882 return OTS_FAILURE(); 883 } 884 } 885 } 886 return true; 887 } 888 889 } // namespace 890 891 namespace ots { 892 893 bool ots_cff_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { 894 Buffer table(data, length); 895 896 file->cff = new OpenTypeCFF; 897 file->cff->data = data; 898 file->cff->length = length; 899 file->cff->font_dict_length = 0; 900 file->cff->local_subrs = NULL; 901 902 // parse "6. Header" in the Adobe Compact Font Format Specification 903 uint8_t major = 0; 904 uint8_t minor = 0; 905 uint8_t hdr_size = 0; 906 uint8_t off_size = 0; 907 if (!table.ReadU8(&major)) { 908 return OTS_FAILURE(); 909 } 910 if (!table.ReadU8(&minor)) { 911 return OTS_FAILURE(); 912 } 913 if (!table.ReadU8(&hdr_size)) { 914 return OTS_FAILURE(); 915 } 916 if (!table.ReadU8(&off_size)) { 917 return OTS_FAILURE(); 918 } 919 if ((off_size == 0) || (off_size > 4)) { 920 return OTS_FAILURE(); 921 } 922 923 if ((major != 1) || 924 (minor != 0) || 925 (hdr_size != 4)) { 926 return OTS_FAILURE(); 927 } 928 if (hdr_size >= length) { 929 return OTS_FAILURE(); 930 } 931 932 // parse "7. Name INDEX" 933 table.set_offset(hdr_size); 934 CFFIndex name_index; 935 if (!ParseIndex(&table, &name_index)) { 936 return OTS_FAILURE(); 937 } 938 if (!ParseNameData(&table, name_index, &(file->cff->name))) { 939 return OTS_FAILURE(); 940 } 941 942 // parse "8. Top DICT INDEX" 943 table.set_offset(name_index.offset_to_next); 944 CFFIndex top_dict_index; 945 if (!ParseIndex(&table, &top_dict_index)) { 946 return OTS_FAILURE(); 947 } 948 if (name_index.count != top_dict_index.count) { 949 return OTS_FAILURE(); 950 } 951 952 // parse "10. String INDEX" 953 table.set_offset(top_dict_index.offset_to_next); 954 CFFIndex string_index; 955 if (!ParseIndex(&table, &string_index)) { 956 return OTS_FAILURE(); 957 } 958 if (string_index.count >= 65000 - kNStdString) { 959 return OTS_FAILURE(); 960 } 961 962 const size_t sid_max = string_index.count + kNStdString; 963 // string_index.count == 0 is allowed. 964 965 // parse "9. Top DICT Data" 966 if (!ParseDictData(data, length, top_dict_index, 967 sid_max, DICT_DATA_TOPLEVEL, file->cff)) { 968 return OTS_FAILURE(); 969 } 970 971 // parse "16. Global Subrs INDEX" 972 table.set_offset(string_index.offset_to_next); 973 CFFIndex global_subrs_index; 974 if (!ParseIndex(&table, &global_subrs_index)) { 975 return OTS_FAILURE(); 976 } 977 978 // Check if all fd_index in FDSelect are valid. 979 std::map<uint16_t, uint8_t>::const_iterator iter; 980 std::map<uint16_t, uint8_t>::const_iterator end = file->cff->fd_select.end(); 981 for (iter = file->cff->fd_select.begin(); iter != end; ++iter) { 982 if (iter->second >= file->cff->font_dict_length) { 983 return OTS_FAILURE(); 984 } 985 } 986 987 // Check if all charstrings (font hinting code for each glyph) are valid. 988 for (size_t i = 0; i < file->cff->char_strings_array.size(); ++i) { 989 if (!ValidateType2CharStringIndex(*(file->cff->char_strings_array.at(i)), 990 global_subrs_index, 991 file->cff->fd_select, 992 file->cff->local_subrs_per_font, 993 file->cff->local_subrs, 994 &table)) { 995 return OTS_FAILURE(); 996 } 997 } 998 999 return true; 1000 } 1001 1002 bool ots_cff_should_serialise(OpenTypeFile *file) { 1003 return file->cff != NULL; 1004 } 1005 1006 bool ots_cff_serialise(OTSStream *out, OpenTypeFile *file) { 1007 // TODO(yusukes): would be better to transcode the data, 1008 // rather than simple memcpy. 1009 if (!out->Write(file->cff->data, file->cff->length)) { 1010 return OTS_FAILURE(); 1011 } 1012 return true; 1013 } 1014 1015 void ots_cff_free(OpenTypeFile *file) { 1016 if (file->cff) { 1017 for (size_t i = 0; i < file->cff->char_strings_array.size(); ++i) { 1018 delete (file->cff->char_strings_array)[i]; 1019 } 1020 for (size_t i = 0; i < file->cff->local_subrs_per_font.size(); ++i) { 1021 delete (file->cff->local_subrs_per_font)[i]; 1022 } 1023 delete file->cff->local_subrs; 1024 delete file->cff; 1025 } 1026 } 1027 1028 } // namespace ots 1029
