ldid.cpp

   1 /* ldid - (Mach-O) Link-Loader Identity Editor
   2  * Copyright (C) 2007-2012  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU Affero General Public License, Version 3 {{{ */
   6 /*
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include "minimal/stdlib.h"
  23
  24 #include <cstring>
  25 #include <string>
  26 #include <vector>
  27
  28 #include <dlfcn.h>
  29 #include <fcntl.h>
  30
  31 #include <sys/mman.h>
  32 #include <sys/stat.h>
  33
  34 #include <openssl/sha.h>
  35
  36 #include <plist/plist.h>
  37
  38 struct fat_header {
  39     uint32_t magic;
  40     uint32_t nfat_arch;
  41 } _packed;
  42
  43 #define FAT_MAGIC 0xcafebabe
  44 #define FAT_CIGAM 0xbebafeca
  45
  46 struct fat_arch {
  47     uint32_t cputype;
  48     uint32_t cpusubtype;
  49     uint32_t offset;
  50     uint32_t size;
  51     uint32_t align;
  52 } _packed;
  53
  54 struct mach_header {
  55     uint32_t magic;
  56     uint32_t cputype;
  57     uint32_t cpusubtype;
  58     uint32_t filetype;
  59     uint32_t ncmds;
  60     uint32_t sizeofcmds;
  61     uint32_t flags;
  62 } _packed;
  63
  64 #define MH_MAGIC 0xfeedface
  65 #define MH_CIGAM 0xcefaedfe
  66
  67 #define MH_MAGIC_64 0xfeedfacf
  68 #define MH_CIGAM_64 0xcffaedfe
  69
  70 #define MH_DYLDLINK   0x4
  71
  72 #define MH_OBJECT     0x1
  73 #define MH_EXECUTE    0x2
  74 #define MH_DYLIB      0x6
  75 #define MH_BUNDLE     0x8
  76 #define MH_DYLIB_STUB 0x9
  77
  78 struct load_command {
  79     uint32_t cmd;
  80     uint32_t cmdsize;
  81 } _packed;
  82
  83 #define LC_REQ_DYLD           uint32_t(0x80000000)
  84
  85 #define LC_SEGMENT            uint32_t(0x01)
  86 #define LC_SYMTAB             uint32_t(0x02)
  87 #define LC_DYSYMTAB           uint32_t(0x0b)
  88 #define LC_LOAD_DYLIB         uint32_t(0x0c)
  89 #define LC_ID_DYLIB           uint32_t(0x0d)
  90 #define LC_SEGMENT_64         uint32_t(0x19)
  91 #define LC_UUID               uint32_t(0x1b)
  92 #define LC_CODE_SIGNATURE     uint32_t(0x1d)
  93 #define LC_SEGMENT_SPLIT_INFO uint32_t(0x1e)
  94 #define LC_REEXPORT_DYLIB     uint32_t(0x1f | LC_REQ_DYLD)
  95 #define LC_ENCRYPTION_INFO    uint32_t(0x21)
  96 #define LC_DYLD_INFO          uint32_t(0x22)
  97 #define LC_DYLD_INFO_ONLY     uint32_t(0x22 | LC_REQ_DYLD)
  98 #define LC_ENCRYPTION_INFO_64 uint32_t(0x2c)
  99
 100 struct dylib {
 101     uint32_t name;
 102     uint32_t timestamp;
 103     uint32_t current_version;
 104     uint32_t compatibility_version;
 105 } _packed;
 106
 107 struct dylib_command {
 108     uint32_t cmd;
 109     uint32_t cmdsize;
 110     struct dylib dylib;
 111 } _packed;
 112
 113 struct uuid_command {
 114     uint32_t cmd;
 115     uint32_t cmdsize;
 116     uint8_t uuid[16];
 117 } _packed;
 118
 119 struct symtab_command {
 120     uint32_t cmd;
 121     uint32_t cmdsize;
 122     uint32_t symoff;
 123     uint32_t nsyms;
 124     uint32_t stroff;
 125     uint32_t strsize;
 126 } _packed;
 127
 128 struct dyld_info_command {
 129     uint32_t cmd;
 130     uint32_t cmdsize;
 131     uint32_t rebase_off;
 132     uint32_t rebase_size;
 133     uint32_t bind_off;
 134     uint32_t bind_size;
 135     uint32_t weak_bind_off;
 136     uint32_t weak_bind_size;
 137     uint32_t lazy_bind_off;
 138     uint32_t lazy_bind_size;
 139     uint32_t export_off;
 140     uint32_t export_size;
 141 } _packed;
 142
 143 struct dysymtab_command {
 144     uint32_t cmd;
 145     uint32_t cmdsize;
 146     uint32_t ilocalsym;
 147     uint32_t nlocalsym;
 148     uint32_t iextdefsym;
 149     uint32_t nextdefsym;
 150     uint32_t iundefsym;
 151     uint32_t nundefsym;
 152     uint32_t tocoff;
 153     uint32_t ntoc;
 154     uint32_t modtaboff;
 155     uint32_t nmodtab;
 156     uint32_t extrefsymoff;
 157     uint32_t nextrefsyms;
 158     uint32_t indirectsymoff;
 159     uint32_t nindirectsyms;
 160     uint32_t extreloff;
 161     uint32_t nextrel;
 162     uint32_t locreloff;
 163     uint32_t nlocrel;
 164 } _packed;
 165
 166 struct dylib_table_of_contents {
 167     uint32_t symbol_index;
 168     uint32_t module_index;
 169 } _packed;
 170
 171 struct dylib_module {
 172     uint32_t module_name;
 173     uint32_t iextdefsym;
 174     uint32_t nextdefsym;
 175     uint32_t irefsym;
 176     uint32_t nrefsym;
 177     uint32_t ilocalsym;
 178     uint32_t nlocalsym;
 179     uint32_t iextrel;
 180     uint32_t nextrel;
 181     uint32_t iinit_iterm;
 182     uint32_t ninit_nterm;
 183     uint32_t objc_module_info_addr;
 184     uint32_t objc_module_info_size;
 185 } _packed;
 186
 187 struct dylib_reference {
 188     uint32_t isym:24;
 189     uint32_t flags:8;
 190 } _packed;
 191
 192 struct relocation_info {
 193     int32_t r_address;
 194     uint32_t r_symbolnum:24;
 195     uint32_t r_pcrel:1;
 196     uint32_t r_length:2;
 197     uint32_t r_extern:1;
 198     uint32_t r_type:4;
 199 } _packed;
 200
 201 struct nlist {
 202     union {
 203         char *n_name;
 204         int32_t n_strx;
 205     } n_un;
 206
 207     uint8_t n_type;
 208     uint8_t n_sect;
 209     uint8_t n_desc;
 210     uint32_t n_value;
 211 } _packed;
 212
 213 struct segment_command {
 214     uint32_t cmd;
 215     uint32_t cmdsize;
 216     char segname[16];
 217     uint32_t vmaddr;
 218     uint32_t vmsize;
 219     uint32_t fileoff;
 220     uint32_t filesize;
 221     uint32_t maxprot;
 222     uint32_t initprot;
 223     uint32_t nsects;
 224     uint32_t flags;
 225 } _packed;
 226
 227 struct segment_command_64 {
 228     uint32_t cmd;
 229     uint32_t cmdsize;
 230     char segname[16];
 231     uint64_t vmaddr;
 232     uint64_t vmsize;
 233     uint64_t fileoff;
 234     uint64_t filesize;
 235     uint32_t maxprot;
 236     uint32_t initprot;
 237     uint32_t nsects;
 238     uint32_t flags;
 239 } _packed;
 240
 241 struct section {
 242     char sectname[16];
 243     char segname[16];
 244     uint32_t addr;
 245     uint32_t size;
 246     uint32_t offset;
 247     uint32_t align;
 248     uint32_t reloff;
 249     uint32_t nreloc;
 250     uint32_t flags;
 251     uint32_t reserved1;
 252     uint32_t reserved2;
 253 } _packed;
 254
 255 struct section_64 {
 256     char sectname[16];
 257     char segname[16];
 258     uint64_t addr;
 259     uint64_t size;
 260     uint32_t offset;
 261     uint32_t align;
 262     uint32_t reloff;
 263     uint32_t nreloc;
 264     uint32_t flags;
 265     uint32_t reserved1;
 266     uint32_t reserved2;
 267 } _packed;
 268
 269 struct linkedit_data_command {
 270     uint32_t cmd;
 271     uint32_t cmdsize;
 272     uint32_t dataoff;
 273     uint32_t datasize;
 274 } _packed;
 275
 276 struct encryption_info_command {
 277     uint32_t cmd;
 278     uint32_t cmdsize;
 279     uint32_t cryptoff;
 280     uint32_t cryptsize;
 281     uint32_t cryptid;
 282 } _packed;
 283
 284 #define BIND_OPCODE_MASK                             0xf0
 285 #define BIND_IMMEDIATE_MASK                          0x0f
 286 #define BIND_OPCODE_DONE                             0x00
 287 #define BIND_OPCODE_SET_DYLIB_ORDINAL_IMM            0x10
 288 #define BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB           0x20
 289 #define BIND_OPCODE_SET_DYLIB_SPECIAL_IMM            0x30
 290 #define BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM    0x40
 291 #define BIND_OPCODE_SET_TYPE_IMM                     0x50
 292 #define BIND_OPCODE_SET_ADDEND_SLEB                  0x60
 293 #define BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB      0x70
 294 #define BIND_OPCODE_ADD_ADDR_ULEB                    0x80
 295 #define BIND_OPCODE_DO_BIND                          0x90
 296 #define BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB            0xa0
 297 #define BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED      0xb0
 298 #define BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB 0xc0
 299
 300 template <typename Type_>
 301 Type_ Align(Type_ value, size_t align) {
 302     value += align - 1;
 303     value /= align;
 304     value *= align;
 305     return value;
 306 }
 307
 308 uint16_t Swap_(uint16_t value) {
 309     return
 310         ((value >>  8) & 0x00ff) |
 311         ((value <<  8) & 0xff00);
 312 }
 313
 314 uint32_t Swap_(uint32_t value) {
 315     value = ((value >>  8) & 0x00ff00ff) |
 316             ((value <<  8) & 0xff00ff00);
 317     value = ((value >> 16) & 0x0000ffff) |
 318             ((value << 16) & 0xffff0000);
 319     return value;
 320 }
 321
 322 uint64_t Swap_(uint64_t value) {
 323     value = (value & 0x00000000ffffffff) << 32 | (value & 0xffffffff00000000) >> 32;
 324     value = (value & 0x0000ffff0000ffff) << 16 | (value & 0xffff0000ffff0000) >> 16;
 325     value = (value & 0x00ff00ff00ff00ff) << 8  | (value & 0xff00ff00ff00ff00) >> 8;
 326     return value;
 327 }
 328
 329 int16_t Swap_(int16_t value) {
 330     return Swap_(static_cast<uint16_t>(value));
 331 }
 332
 333 int32_t Swap_(int32_t value) {
 334     return Swap_(static_cast<uint32_t>(value));
 335 }
 336
 337 int64_t Swap_(int64_t value) {
 338     return Swap_(static_cast<uint64_t>(value));
 339 }
 340
 341 bool little_(true);
 342
 343 uint16_t Swap(uint16_t value) {
 344     return little_ ? Swap_(value) : value;
 345 }
 346
 347 uint32_t Swap(uint32_t value) {
 348     return little_ ? Swap_(value) : value;
 349 }
 350
 351 uint64_t Swap(uint64_t value) {
 352     return little_ ? Swap_(value) : value;
 353 }
 354
 355 int16_t Swap(int16_t value) {
 356     return Swap(static_cast<uint16_t>(value));
 357 }
 358
 359 int32_t Swap(int32_t value) {
 360     return Swap(static_cast<uint32_t>(value));
 361 }
 362
 363 int64_t Swap(int64_t value) {
 364     return Swap(static_cast<uint64_t>(value));
 365 }
 366
 367 template <typename Target_>
 368 class Pointer;
 369
 370 class Data {
 371   private:
 372     void *base_;
 373     size_t size_;
 374
 375   protected:
 376     bool swapped_;
 377
 378   public:
 379     Data(void *base, size_t size) :
 380         base_(base),
 381         size_(size),
 382         swapped_(false)
 383     {
 384     }
 385
 386     uint16_t Swap(uint16_t value) const {
 387         return swapped_ ? Swap_(value) : value;
 388     }
 389
 390     uint32_t Swap(uint32_t value) const {
 391         return swapped_ ? Swap_(value) : value;
 392     }
 393
 394     uint64_t Swap(uint64_t value) const {
 395         return swapped_ ? Swap_(value) : value;
 396     }
 397
 398     int16_t Swap(int16_t value) const {
 399         return Swap(static_cast<uint16_t>(value));
 400     }
 401
 402     int32_t Swap(int32_t value) const {
 403         return Swap(static_cast<uint32_t>(value));
 404     }
 405
 406     int64_t Swap(int64_t value) const {
 407         return Swap(static_cast<uint64_t>(value));
 408     }
 409
 410     void *GetBase() const {
 411         return base_;
 412     }
 413
 414     size_t GetSize() const {
 415         return size_;
 416     }
 417 };
 418
 419 class MachHeader :
 420     public Data
 421 {
 422   private:
 423     bool bits64_;
 424
 425     struct mach_header *mach_header_;
 426     struct load_command *load_command_;
 427
 428   public:
 429     MachHeader(void *base, size_t size) :
 430         Data(base, size)
 431     {
 432         mach_header_ = (mach_header *) base;
 433
 434         switch (Swap(mach_header_->magic)) {
 435             case MH_CIGAM:
 436                 swapped_ = !swapped_;
 437             case MH_MAGIC:
 438                 bits64_ = false;
 439             break;
 440
 441             case MH_CIGAM_64:
 442                 swapped_ = !swapped_;
 443             case MH_MAGIC_64:
 444                 bits64_ = true;
 445             break;
 446
 447             default:
 448                 _assert(false);
 449         }
 450
 451         void *post = mach_header_ + 1;
 452         if (bits64_)
 453             post = (uint32_t *) post + 1;
 454         load_command_ = (struct load_command *) post;
 455
 456         _assert(
 457             Swap(mach_header_->filetype) == MH_EXECUTE ||
 458             Swap(mach_header_->filetype) == MH_DYLIB ||
 459             Swap(mach_header_->filetype) == MH_BUNDLE
 460         );
 461     }
 462
 463     struct mach_header *operator ->() const {
 464         return mach_header_;
 465     }
 466
 467     operator struct mach_header *() const {
 468         return mach_header_;
 469     }
 470
 471     uint32_t GetCPUType() const {
 472         return Swap(mach_header_->cputype);
 473     }
 474
 475     uint32_t GetCPUSubtype() const {
 476         return Swap(mach_header_->cpusubtype) & 0xff;
 477     }
 478
 479     struct load_command *GetLoadCommand() const {
 480         return load_command_;
 481     }
 482
 483     std::vector<struct load_command *> GetLoadCommands() const {
 484         std::vector<struct load_command *> load_commands;
 485
 486         struct load_command *load_command = load_command_;
 487         for (uint32_t cmd = 0; cmd != Swap(mach_header_->ncmds); ++cmd) {
 488             load_commands.push_back(load_command);
 489             load_command = (struct load_command *) ((uint8_t *) load_command + Swap(load_command->cmdsize));
 490         }
 491
 492         return load_commands;
 493     }
 494
 495     std::vector<segment_command *> GetSegments(const char *segment_name) const {
 496         std::vector<struct segment_command *> segment_commands;
 497
 498         _foreach (load_command, GetLoadCommands()) {
 499             if (Swap(load_command->cmd) == LC_SEGMENT) {
 500                 segment_command *segment_command = reinterpret_cast<struct segment_command *>(load_command);
 501                 if (strncmp(segment_command->segname, segment_name, 16) == 0)
 502                     segment_commands.push_back(segment_command);
 503             }
 504         }
 505
 506         return segment_commands;
 507     }
 508
 509     std::vector<segment_command_64 *> GetSegments64(const char *segment_name) const {
 510         std::vector<struct segment_command_64 *> segment_commands;
 511
 512         _foreach (load_command, GetLoadCommands()) {
 513             if (Swap(load_command->cmd) == LC_SEGMENT_64) {
 514                 segment_command_64 *segment_command = reinterpret_cast<struct segment_command_64 *>(load_command);
 515                 if (strncmp(segment_command->segname, segment_name, 16) == 0)
 516                     segment_commands.push_back(segment_command);
 517             }
 518         }
 519
 520         return segment_commands;
 521     }
 522
 523     std::vector<section *> GetSections(const char *segment_name, const char *section_name) const {
 524         std::vector<section *> sections;
 525
 526         _foreach (segment, GetSegments(segment_name)) {
 527             section *section = (struct section *) (segment + 1);
 528
 529             uint32_t sect;
 530             for (sect = 0; sect != Swap(segment->nsects); ++sect) {
 531                 if (strncmp(section->sectname, section_name, 16) == 0)
 532                     sections.push_back(section);
 533                 ++section;
 534             }
 535         }
 536
 537         return sections;
 538     }
 539
 540     template <typename Target_>
 541     Pointer<Target_> GetPointer(uint32_t address, const char *segment_name = NULL) const {
 542         load_command *load_command = (struct load_command *) (mach_header_ + 1);
 543         uint32_t cmd;
 544
 545         for (cmd = 0; cmd != Swap(mach_header_->ncmds); ++cmd) {
 546             if (Swap(load_command->cmd) == LC_SEGMENT) {
 547                 segment_command *segment_command = (struct segment_command *) load_command;
 548                 if (segment_name != NULL && strncmp(segment_command->segname, segment_name, 16) != 0)
 549                     goto next_command;
 550
 551                 section *sections = (struct section *) (segment_command + 1);
 552
 553                 uint32_t sect;
 554                 for (sect = 0; sect != Swap(segment_command->nsects); ++sect) {
 555                     section *section = &sections[sect];
 556                     //printf("%s %u %p %p %u\n", segment_command->segname, sect, address, section->addr, section->size);
 557                     if (address >= Swap(section->addr) && address < Swap(section->addr) + Swap(section->size)) {
 558                         //printf("0x%.8x %s\n", address, segment_command->segname);
 559                         return Pointer<Target_>(this, reinterpret_cast<Target_ *>(address - Swap(section->addr) + Swap(section->offset) + (char *) mach_header_));
 560                     }
 561                 }
 562             }
 563
 564           next_command:
 565             load_command = (struct load_command *) ((char *) load_command + Swap(load_command->cmdsize));
 566         }
 567
 568         return Pointer<Target_>(this);
 569     }
 570
 571     template <typename Target_>
 572     Pointer<Target_> GetOffset(uint32_t offset) {
 573         return Pointer<Target_>(this, reinterpret_cast<Target_ *>(offset + (uint8_t *) mach_header_));
 574     }
 575 };
 576
 577 class FatMachHeader :
 578     public MachHeader
 579 {
 580   private:
 581     fat_arch *fat_arch_;
 582
 583   public:
 584     FatMachHeader(void *base, size_t size, fat_arch *fat_arch) :
 585         MachHeader(base, size),
 586         fat_arch_(fat_arch)
 587     {
 588     }
 589
 590     fat_arch *GetFatArch() const {
 591         return fat_arch_;
 592     }
 593 };
 594
 595 class FatHeader :
 596     public Data
 597 {
 598   private:
 599     fat_header *fat_header_;
 600     std::vector<FatMachHeader> mach_headers_;
 601
 602   public:
 603     FatHeader(void *base, size_t size) :
 604         Data(base, size)
 605     {
 606         fat_header_ = reinterpret_cast<struct fat_header *>(base);
 607
 608         if (Swap(fat_header_->magic) == FAT_CIGAM) {
 609             swapped_ = !swapped_;
 610             goto fat;
 611         } else if (Swap(fat_header_->magic) != FAT_MAGIC) {
 612             fat_header_ = NULL;
 613             mach_headers_.push_back(FatMachHeader(base, size, NULL));
 614         } else fat: {
 615             size_t fat_narch = Swap(fat_header_->nfat_arch);
 616             fat_arch *fat_arch = reinterpret_cast<struct fat_arch *>(fat_header_ + 1);
 617             size_t arch;
 618             for (arch = 0; arch != fat_narch; ++arch) {
 619                 uint32_t arch_offset = Swap(fat_arch->offset);
 620                 uint32_t arch_size = Swap(fat_arch->size);
 621                 mach_headers_.push_back(FatMachHeader((uint8_t *) base + arch_offset, arch_size, fat_arch));
 622                 ++fat_arch;
 623             }
 624         }
 625     }
 626
 627     std::vector<FatMachHeader> &GetMachHeaders() {
 628         return mach_headers_;
 629     }
 630
 631     bool IsFat() const {
 632         return fat_header_ != NULL;
 633     }
 634
 635     struct fat_header *operator ->() const {
 636         return fat_header_;
 637     }
 638
 639     operator struct fat_header *() const {
 640         return fat_header_;
 641     }
 642 };
 643
 644 template <typename Target_>
 645 class Pointer {
 646   private:
 647     const MachHeader *framework_;
 648     const Target_ *pointer_;
 649
 650   public:
 651     Pointer(const MachHeader *framework = NULL, const Target_ *pointer = NULL) :
 652         framework_(framework),
 653         pointer_(pointer)
 654     {
 655     }
 656
 657     operator const Target_ *() const {
 658         return pointer_;
 659     }
 660
 661     const Target_ *operator ->() const {
 662         return pointer_;
 663     }
 664
 665     Pointer<Target_> &operator ++() {
 666         ++pointer_;
 667         return *this;
 668     }
 669
 670     template <typename Value_>
 671     Value_ Swap(Value_ value) {
 672         return framework_->Swap(value);
 673     }
 674 };
 675
 676 #define CSMAGIC_CODEDIRECTORY      uint32_t(0xfade0c02)
 677 #define CSMAGIC_EMBEDDED_SIGNATURE uint32_t(0xfade0cc0)
 678 #define CSMAGIC_ENTITLEMENTS       uint32_t(0xfade7171)
 679
 680 #define CSSLOT_CODEDIRECTORY uint32_t(0)
 681 #define CSSLOT_REQUIREMENTS  uint32_t(2)
 682 #define CSSLOT_ENTITLEMENTS  uint32_t(5)
 683
 684 struct BlobIndex {
 685     uint32_t type;
 686     uint32_t offset;
 687 } _packed;
 688
 689 struct Blob {
 690     uint32_t magic;
 691     uint32_t length;
 692 } _packed;
 693
 694 struct SuperBlob {
 695     struct Blob blob;
 696     uint32_t count;
 697     struct BlobIndex index[];
 698 } _packed;
 699
 700 struct CodeDirectory {
 701     struct Blob blob;
 702     uint32_t version;
 703     uint32_t flags;
 704     uint32_t hashOffset;
 705     uint32_t identOffset;
 706     uint32_t nSpecialSlots;
 707     uint32_t nCodeSlots;
 708     uint32_t codeLimit;
 709     uint8_t hashSize;
 710     uint8_t hashType;
 711     uint8_t spare1;
 712     uint8_t pageSize;
 713     uint32_t spare2;
 714 } _packed;
 715
 716 extern "C" uint32_t hash(uint8_t *k, uint32_t length, uint32_t initval);
 717
 718 void sha1(uint8_t *hash, uint8_t *data, size_t size) {
 719     SHA1(data, size, hash);
 720 }
 721
 722 struct CodesignAllocation {
 723     FatMachHeader mach_header_;
 724     uint32_t offset_;
 725     uint32_t size_;
 726     uint32_t alloc_;
 727     uint32_t align_;
 728
 729     CodesignAllocation(FatMachHeader mach_header, size_t offset, size_t size, size_t alloc, size_t align) :
 730         mach_header_(mach_header),
 731         offset_(offset),
 732         size_(size),
 733         alloc_(alloc),
 734         align_(align)
 735     {
 736     }
 737 };
 738
 739 class File {
 740   private:
 741     int file_;
 742
 743   public:
 744     File() :
 745         file_(-1)
 746     {
 747     }
 748
 749     ~File() {
 750         if (file_ != -1)
 751             _syscall(close(file_));
 752     }
 753
 754     void open(const char *path, int flags) {
 755         _assert(file_ == -1);
 756         _syscall(file_ = ::open(path, flags));
 757     }
 758
 759     int file() const {
 760         return file_;
 761     }
 762 };
 763
 764 class Map {
 765   private:
 766     File file_;
 767     void *data_;
 768     size_t size_;
 769
 770     void clear() {
 771         if (data_ == NULL)
 772             return;
 773         _syscall(munmap(data_, size_));
 774         data_ = NULL;
 775         size_ = 0;
 776     }
 777
 778   public:
 779     Map() :
 780         data_(NULL),
 781         size_(0)
 782     {
 783     }
 784
 785     Map(const char *path, int oflag, int pflag, int mflag) :
 786         Map()
 787     {
 788         open(path, oflag, pflag, mflag);
 789     }
 790
 791     Map(const char *path, bool edit) :
 792         Map()
 793     {
 794         open(path, edit);
 795     }
 796
 797     ~Map() {
 798         clear();
 799     }
 800
 801     void open(const char *path, int oflag, int pflag, int mflag) {
 802         clear();
 803
 804         file_.open(path, oflag);
 805         int file(file_.file());
 806
 807         struct stat stat;
 808         _syscall(fstat(file, &stat));
 809         size_ = stat.st_size;
 810
 811         _syscall(data_ = mmap(NULL, size_, pflag, mflag, file, 0));
 812     }
 813
 814     void open(const char *path, bool edit) {
 815         if (edit)
 816             open(path, O_RDWR, PROT_READ | PROT_WRITE, MAP_SHARED);
 817         else
 818             open(path, O_RDONLY, PROT_READ, MAP_PRIVATE);
 819     }
 820
 821     void *data() const {
 822         return data_;
 823     }
 824
 825     size_t size() const {
 826         return size_;
 827     }
 828
 829     operator std::string() const {
 830         return std::string(static_cast<char *>(data_), size_);
 831     }
 832 };
 833
 834 void resign(const char *path, const char *temp, const char *name, const std::string &xml) {
 835     Map input(path, O_RDONLY, PROT_READ | PROT_WRITE, MAP_PRIVATE);
 836     FatHeader source(input.data(), input.size());
 837
 838     size_t offset(0);
 839     if (source.IsFat())
 840         offset += sizeof(fat_header) + sizeof(fat_arch) * source.Swap(source->nfat_arch);
 841
 842     std::vector<CodesignAllocation> allocations;
 843     _foreach (mach_header, source.GetMachHeaders()) {
 844         struct linkedit_data_command *signature(NULL);
 845         struct symtab_command *symtab(NULL);
 846
 847         _foreach (load_command, mach_header.GetLoadCommands()) {
 848             uint32_t cmd(mach_header.Swap(load_command->cmd));
 849             if (false);
 850             else if (cmd == LC_CODE_SIGNATURE)
 851                 signature = reinterpret_cast<struct linkedit_data_command *>(load_command);
 852             else if (cmd == LC_SYMTAB)
 853                 symtab = reinterpret_cast<struct symtab_command *>(load_command);
 854         }
 855
 856         size_t size;
 857         if (signature == NULL)
 858             size = mach_header.GetSize();
 859         else {
 860             size = mach_header.Swap(signature->dataoff);
 861             _assert(size <= mach_header.GetSize());
 862         }
 863
 864         if (symtab != NULL) {
 865             auto end(mach_header.Swap(symtab->stroff) + mach_header.Swap(symtab->strsize));
 866             _assert(end <= size);
 867             _assert(end >= size - 0x10);
 868             size = end;
 869         }
 870
 871         size_t alloc(0);
 872         if (name != NULL) {
 873             alloc += sizeof(struct SuperBlob);
 874             uint32_t special(0);
 875
 876             special = std::max(special, CSSLOT_CODEDIRECTORY);
 877             alloc += sizeof(struct BlobIndex);
 878             alloc += sizeof(struct CodeDirectory);
 879             alloc += strlen(name) + 1;
 880
 881             special = std::max(special, CSSLOT_REQUIREMENTS);
 882             alloc += sizeof(struct BlobIndex);
 883             alloc += 0xc;
 884
 885             if (xml.size() != 0) {
 886                 special = std::max(special, CSSLOT_ENTITLEMENTS);
 887                 alloc += sizeof(struct BlobIndex);
 888                 alloc += sizeof(struct Blob);
 889                 alloc += xml.size();
 890             }
 891
 892             size_t normal((size + 0x1000 - 1) / 0x1000);
 893             alloc = Align(alloc + (special + normal) * 0x14, 16);
 894         }
 895
 896         auto *fat_arch(mach_header.GetFatArch());
 897         uint32_t align(fat_arch == NULL ? 0 : source.Swap(fat_arch->align));
 898         offset = Align(offset, 1 << align);
 899
 900         allocations.push_back(CodesignAllocation(mach_header, offset, size, alloc, align));
 901         offset += size + alloc;
 902         offset = Align(offset, 16);
 903     }
 904
 905     fclose(fopen(temp, "w+"));
 906     _syscall(truncate(temp, offset));
 907
 908     Map output(temp, O_RDWR, PROT_READ | PROT_WRITE, MAP_SHARED);
 909     _assert(output.size() == offset);
 910     void *file(output.data());
 911     memset(file, 0, offset);
 912
 913     fat_arch *fat_arch;
 914     if (!source.IsFat())
 915         fat_arch = NULL;
 916     else {
 917         auto *fat_header(reinterpret_cast<struct fat_header *>(file));
 918         fat_header->magic = Swap(FAT_MAGIC);
 919         fat_header->nfat_arch = Swap(source.Swap(source->nfat_arch));
 920         fat_arch = reinterpret_cast<struct fat_arch *>(fat_header + 1);
 921     }
 922
 923     _foreach (allocation, allocations) {
 924         auto &source(allocation.mach_header_);
 925
 926         uint32_t align(allocation.size_);
 927         if (allocation.alloc_ != 0)
 928             align = Align(align, 0x10);
 929
 930         if (fat_arch != NULL) {
 931             fat_arch->cputype = Swap(source->cputype);
 932             fat_arch->cpusubtype = Swap(source->cpusubtype);
 933             fat_arch->offset = Swap(allocation.offset_);
 934             fat_arch->size = Swap(align + allocation.alloc_);
 935             fat_arch->align = Swap(allocation.align_);
 936             ++fat_arch;
 937         }
 938
 939         void *target(reinterpret_cast<uint8_t *>(file) + allocation.offset_);
 940         memcpy(target, source, allocation.size_);
 941         MachHeader mach_header(target, align + allocation.alloc_);
 942
 943         struct linkedit_data_command *signature(NULL);
 944         _foreach (load_command, mach_header.GetLoadCommands()) {
 945             uint32_t cmd(mach_header.Swap(load_command->cmd));
 946             if (cmd != LC_CODE_SIGNATURE)
 947                 continue;
 948             signature = reinterpret_cast<struct linkedit_data_command *>(load_command);
 949             break;
 950         }
 951
 952         _foreach (segment, mach_header.GetSegments("__LINKEDIT")) {
 953             size_t size(mach_header.Swap(align + allocation.alloc_ - mach_header.Swap(segment->fileoff)));
 954             segment->filesize = size;
 955             segment->vmsize = Align(size, 0x1000);
 956         }
 957
 958         _foreach (segment, mach_header.GetSegments64("__LINKEDIT")) {
 959             size_t size(mach_header.Swap(align + allocation.alloc_ - mach_header.Swap(segment->fileoff)));
 960             segment->filesize = size;
 961             segment->vmsize = Align(size, 0x1000);
 962         }
 963
 964         if (name == NULL && signature != NULL) {
 965             auto before(reinterpret_cast<uint8_t *>(mach_header.GetLoadCommand()));
 966             auto after(reinterpret_cast<uint8_t *>(signature));
 967             auto next(mach_header.Swap(signature->cmdsize));
 968             auto total(mach_header.Swap(mach_header->sizeofcmds));
 969             memmove(signature, after + next, before + total - after - next);
 970             memset(before + total - next, 0, next);
 971             mach_header->ncmds = mach_header.Swap(mach_header.Swap(mach_header->ncmds) - 1);
 972             mach_header->sizeofcmds = mach_header.Swap(total - next);
 973             signature = NULL;
 974         }
 975
 976         if (name != NULL) {
 977             if (signature == NULL) {
 978                 signature = reinterpret_cast<struct linkedit_data_command *>(reinterpret_cast<uint8_t *>(mach_header.GetLoadCommand()) + mach_header.Swap(mach_header->sizeofcmds));
 979                 signature->cmd = mach_header.Swap(LC_CODE_SIGNATURE);
 980                 signature->cmdsize = mach_header.Swap(uint32_t(sizeof(*signature)));
 981                 mach_header->ncmds = mach_header.Swap(mach_header.Swap(mach_header->ncmds) + 1);
 982                 mach_header->sizeofcmds = mach_header.Swap(mach_header.Swap(mach_header->sizeofcmds) + uint32_t(sizeof(*signature)));
 983             }
 984
 985             signature->dataoff = mach_header.Swap(align);
 986             signature->datasize = mach_header.Swap(allocation.alloc_);
 987
 988             uint32_t data = mach_header.Swap(signature->dataoff);
 989             uint32_t size = mach_header.Swap(signature->datasize);
 990
 991             uint8_t *top = reinterpret_cast<uint8_t *>(mach_header.GetBase());
 992             uint8_t *blob = top + data;
 993             struct SuperBlob *super = reinterpret_cast<struct SuperBlob *>(blob);
 994             super->blob.magic = Swap(CSMAGIC_EMBEDDED_SIGNATURE);
 995
 996             uint32_t count = xml.size() == 0 ? 2 : 3;
 997             uint32_t offset = sizeof(struct SuperBlob) + count * sizeof(struct BlobIndex);
 998
 999             super->index[0].type = Swap(CSSLOT_CODEDIRECTORY);
1000             super->index[0].offset = Swap(offset);
1001
1002             uint32_t begin = offset;
1003             struct CodeDirectory *directory = reinterpret_cast<struct CodeDirectory *>(blob + begin);
1004             offset += sizeof(struct CodeDirectory);
1005
1006             directory->blob.magic = Swap(CSMAGIC_CODEDIRECTORY);
1007             directory->version = Swap(uint32_t(0x00020001));
1008             directory->flags = Swap(uint32_t(0));
1009             directory->codeLimit = Swap(data);
1010             directory->hashSize = 0x14;
1011             directory->hashType = 0x01;
1012             directory->spare1 = 0x00;
1013             directory->pageSize = 0x0c;
1014             directory->spare2 = Swap(uint32_t(0));
1015
1016             directory->identOffset = Swap(offset - begin);
1017             strcpy(reinterpret_cast<char *>(blob + offset), name);
1018             offset += strlen(name) + 1;
1019
1020             uint32_t special = xml.size() == 0 ? CSSLOT_REQUIREMENTS : CSSLOT_ENTITLEMENTS;
1021             directory->nSpecialSlots = Swap(special);
1022
1023             uint8_t (*hashes)[20] = reinterpret_cast<uint8_t (*)[20]>(blob + offset);
1024             memset(hashes, 0, sizeof(*hashes) * special);
1025
1026             offset += sizeof(*hashes) * special;
1027             hashes += special;
1028
1029             uint32_t pages = (data + 0x1000 - 1) / 0x1000;
1030             directory->nCodeSlots = Swap(pages);
1031
1032             if (pages != 1)
1033                 for (size_t i = 0; i != pages - 1; ++i)
1034                     sha1(hashes[i], top + 0x1000 * i, 0x1000);
1035             if (pages != 0)
1036                 sha1(hashes[pages - 1], top + 0x1000 * (pages - 1), ((data - 1) % 0x1000) + 1);
1037
1038             directory->hashOffset = Swap(offset - begin);
1039             offset += sizeof(*hashes) * pages;
1040             directory->blob.length = Swap(offset - begin);
1041
1042             super->index[1].type = Swap(CSSLOT_REQUIREMENTS);
1043             super->index[1].offset = Swap(offset);
1044
1045             memcpy(blob + offset, "\xfa\xde\x0c\x01\x00\x00\x00\x0c\x00\x00\x00\x00", 0xc);
1046             offset += 0xc;
1047
1048             if (xml.size() != 0) {
1049                 super->index[2].type = Swap(CSSLOT_ENTITLEMENTS);
1050                 super->index[2].offset = Swap(offset);
1051
1052                 uint32_t begin = offset;
1053                 struct Blob *entitlements = reinterpret_cast<struct Blob *>(blob + begin);
1054                 offset += sizeof(struct Blob);
1055
1056                 memcpy(blob + offset, xml.data(), xml.size());
1057                 offset += xml.size();
1058
1059                 entitlements->magic = Swap(CSMAGIC_ENTITLEMENTS);
1060                 entitlements->length = Swap(offset - begin);
1061             }
1062
1063             for (size_t index(0); index != count; ++index) {
1064                 uint32_t type = Swap(super->index[index].type);
1065                 if (type != 0 && type <= special) {
1066                     uint32_t offset = Swap(super->index[index].offset);
1067                     struct Blob *local = (struct Blob *) (blob + offset);
1068                     sha1((uint8_t *) (hashes - type), (uint8_t *) local, Swap(local->length));
1069                 }
1070             }
1071
1072             super->count = Swap(count);
1073             super->blob.length = Swap(offset);
1074
1075             if (offset > size) {
1076                 fprintf(stderr, "offset (%u) > size (%u)\n", offset, size);
1077                 _assert(false);
1078             } //else fprintf(stderr, "offset (%zu) <= size (%zu)\n", offset, size);
1079
1080             memset(blob + offset, 0, size - offset);
1081         }
1082     }
1083 }
1084
1085 int main(int argc, const char *argv[]) {
1086     union {
1087         uint16_t word;
1088         uint8_t byte[2];
1089     } endian = {1};
1090
1091     little_ = endian.byte[0];
1092
1093     bool flag_r(false);
1094     bool flag_e(false);
1095
1096     bool flag_T(false);
1097
1098     bool flag_S(false);
1099     bool flag_s(false);
1100
1101     bool flag_D(false);
1102
1103     bool flag_A(false);
1104     bool flag_a(false);
1105
1106     uint32_t flag_CPUType(_not(uint32_t));
1107     uint32_t flag_CPUSubtype(_not(uint32_t));
1108
1109     const char *flag_I(NULL);
1110
1111     bool timeh(false);
1112     uint32_t timev(0);
1113
1114     Map xmlm;
1115
1116     std::vector<std::string> files;
1117
1118     if (argc == 1) {
1119         fprintf(stderr, "usage: %s -S[entitlements.xml] <binary>\n", argv[0]);
1120         fprintf(stderr, "   %s -e MobileSafari\n", argv[0]);
1121         fprintf(stderr, "   %s -S cat\n", argv[0]);
1122         fprintf(stderr, "   %s -Stfp.xml gdb\n", argv[0]);
1123         exit(0);
1124     }
1125
1126     for (int argi(1); argi != argc; ++argi)
1127         if (argv[argi][0] != '-')
1128             files.push_back(argv[argi]);
1129         else switch (argv[argi][1]) {
1130             case 'r': flag_r = true; break;
1131             case 'e': flag_e = true; break;
1132
1133             case 'D': flag_D = true; break;
1134
1135             case 'a': flag_a = true; break;
1136
1137             case 'A':
1138                 flag_A = true;
1139                 if (argv[argi][2] != '\0') {
1140                     const char *cpu = argv[argi] + 2;
1141                     const char *colon = strchr(cpu, ':');
1142                     _assert(colon != NULL);
1143                     char *arge;
1144                     flag_CPUType = strtoul(cpu, &arge, 0);
1145                     _assert(arge == colon);
1146                     flag_CPUSubtype = strtoul(colon + 1, &arge, 0);
1147                     _assert(arge == argv[argi] + strlen(argv[argi]));
1148                 }
1149             break;
1150
1151             case 's':
1152                 _assert(!flag_S);
1153                 flag_s = true;
1154             break;
1155
1156             case 'S':
1157                 _assert(!flag_s);
1158                 flag_S = true;
1159                 if (argv[argi][2] != '\0') {
1160                     const char *xml = argv[argi] + 2;
1161                     xmlm.open(xml, O_RDONLY, PROT_READ, MAP_PRIVATE);
1162                 }
1163             break;
1164
1165             case 'T': {
1166                 flag_T = true;
1167                 if (argv[argi][2] == '-')
1168                     timeh = true;
1169                 else {
1170                     char *arge;
1171                     timev = strtoul(argv[argi] + 2, &arge, 0);
1172                     _assert(arge == argv[argi] + strlen(argv[argi]));
1173                 }
1174             } break;
1175
1176             case 'I': {
1177                 flag_I = argv[argi] + 2;
1178             } break;
1179
1180             default:
1181                 goto usage;
1182             break;
1183         }
1184
1185     _assert(!flag_S || !flag_r);
1186
1187     if (files.empty()) usage: {
1188         exit(0);
1189     }
1190
1191     size_t filei(0), filee(0);
1192     _foreach (file, files) try {
1193         const char *path(file.c_str());
1194         const char *base = strrchr(path, '/');
1195
1196         std::string dir;
1197         if (base != NULL)
1198             dir.assign(path, base++ - path + 1);
1199         else
1200             base = path;
1201
1202         const char *name(flag_I ?: base);
1203         char *temp(NULL);
1204
1205         if (flag_S || flag_r) {
1206             asprintf(&temp, "%s.%s.cs", dir.c_str(), base);
1207             resign(path, temp, flag_S ? name : NULL, xmlm);
1208         }
1209
1210         Map mapping(temp ?: path, flag_T || flag_s);
1211         FatHeader fat_header(mapping.data(), mapping.size());
1212
1213         _foreach (mach_header, fat_header.GetMachHeaders()) {
1214             struct linkedit_data_command *signature(NULL);
1215             struct encryption_info_command *encryption(NULL);
1216
1217             if (flag_A) {
1218                 if (mach_header.GetCPUType() != flag_CPUType)
1219                     continue;
1220                 if (mach_header.GetCPUSubtype() != flag_CPUSubtype)
1221                     continue;
1222             }
1223
1224             if (flag_a)
1225                 printf("cpu=0x%x:0x%x\n", mach_header.GetCPUType(), mach_header.GetCPUSubtype());
1226
1227             _foreach (load_command, mach_header.GetLoadCommands()) {
1228                 uint32_t cmd(mach_header.Swap(load_command->cmd));
1229
1230                 if (false);
1231                 else if (cmd == LC_CODE_SIGNATURE)
1232                     signature = reinterpret_cast<struct linkedit_data_command *>(load_command);
1233                 else if (cmd == LC_ENCRYPTION_INFO || cmd == LC_ENCRYPTION_INFO_64)
1234                     encryption = reinterpret_cast<struct encryption_info_command *>(load_command);
1235                 else if (cmd == LC_ID_DYLIB) {
1236                     volatile struct dylib_command *dylib_command(reinterpret_cast<struct dylib_command *>(load_command));
1237
1238                     if (flag_T) {
1239                         uint32_t timed;
1240
1241                         if (!timeh)
1242                             timed = timev;
1243                         else {
1244                             dylib_command->dylib.timestamp = 0;
1245                             timed = hash(reinterpret_cast<uint8_t *>(mach_header.GetBase()), mach_header.GetSize(), timev);
1246                         }
1247
1248                         dylib_command->dylib.timestamp = mach_header.Swap(timed);
1249                     }
1250                 }
1251             }
1252
1253             if (flag_D) {
1254                 _assert(encryption != NULL);
1255                 encryption->cryptid = mach_header.Swap(0);
1256             }
1257
1258             if (flag_e) {
1259                 _assert(signature != NULL);
1260
1261                 uint32_t data = mach_header.Swap(signature->dataoff);
1262
1263                 uint8_t *top = reinterpret_cast<uint8_t *>(mach_header.GetBase());
1264                 uint8_t *blob = top + data;
1265                 struct SuperBlob *super = reinterpret_cast<struct SuperBlob *>(blob);
1266
1267                 for (size_t index(0); index != Swap(super->count); ++index)
1268                     if (Swap(super->index[index].type) == CSSLOT_ENTITLEMENTS) {
1269                         uint32_t begin = Swap(super->index[index].offset);
1270                         struct Blob *entitlements = reinterpret_cast<struct Blob *>(blob + begin);
1271                         fwrite(entitlements + 1, 1, Swap(entitlements->length) - sizeof(struct Blob), stdout);
1272                     }
1273             }
1274
1275             if (flag_s) {
1276                 _assert(signature != NULL);
1277
1278                 uint32_t data = mach_header.Swap(signature->dataoff);
1279
1280                 uint8_t *top = reinterpret_cast<uint8_t *>(mach_header.GetBase());
1281                 uint8_t *blob = top + data;
1282                 struct SuperBlob *super = reinterpret_cast<struct SuperBlob *>(blob);
1283
1284                 for (size_t index(0); index != Swap(super->count); ++index)
1285                     if (Swap(super->index[index].type) == CSSLOT_CODEDIRECTORY) {
1286                         uint32_t begin = Swap(super->index[index].offset);
1287                         struct CodeDirectory *directory = reinterpret_cast<struct CodeDirectory *>(blob + begin);
1288
1289                         uint8_t (*hashes)[20] = reinterpret_cast<uint8_t (*)[20]>(blob + begin + Swap(directory->hashOffset));
1290                         uint32_t pages = Swap(directory->nCodeSlots);
1291
1292                         if (pages != 1)
1293                             for (size_t i = 0; i != pages - 1; ++i)
1294                                 sha1(hashes[i], top + 0x1000 * i, 0x1000);
1295                         if (pages != 0)
1296                             sha1(hashes[pages - 1], top + 0x1000 * (pages - 1), ((data - 1) % 0x1000) + 1);
1297                     }
1298             }
1299         }
1300
1301         if (temp != NULL) {
1302             struct stat info;
1303             _syscall(stat(path, &info));
1304             _syscall(chown(temp, info.st_uid, info.st_gid));
1305             _syscall(chmod(temp, info.st_mode));
1306             _syscall(unlink(path));
1307             _syscall(rename(temp, path));
1308             free(temp);
1309         }
1310
1311         ++filei;
1312     } catch (const char *) {
1313         ++filee;
1314         ++filei;
1315     }
1316
1317     return filee;
1318 }