ldid.cpp

   1 /* JocStrap - Java/Objective-C Bootstrap
   2  * Copyright (C) 2007  Jay Freeman (saurik)
   3 */
   4
   5 /*
   6  *        Redistribution and use in source and binary
   7  * forms, with or without modification, are permitted
   8  * provided that the following conditions are met:
   9  *
  10  * 1. Redistributions of source code must retain the
  11  *    above copyright notice, this list of conditions
  12  *    and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the
  14  *    above copyright notice, this list of conditions
  15  *    and the following disclaimer in the documentation
  16  *    and/or other materials provided with the
  17  *    distribution.
  18  * 3. The name of the author may not be used to endorse
  19  *    or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS''
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
  24  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
  27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  28  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  30  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  33  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  34  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  35  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36 */
  37
  38 #include "minimal/stdlib.h"
  39 #include "minimal/string.h"
  40 #include "minimal/mapping.h"
  41
  42 #include "sha1.h"
  43
  44 #include <cstring>
  45 #include <string>
  46 #include <vector>
  47
  48 #include <sys/wait.h>
  49 #include <sys/types.h>
  50 #include <sys/stat.h>
  51
  52 struct fat_header {
  53     uint32_t magic;
  54     uint32_t nfat_arch;
  55 } _packed;
  56
  57 #define FAT_MAGIC 0xcafebabe
  58 #define FAT_CIGAM 0xbebafeca
  59
  60 struct fat_arch {
  61     uint32_t cputype;
  62     uint32_t cpusubtype;
  63     uint32_t offset;
  64     uint32_t size;
  65     uint32_t align;
  66 } _packed;
  67
  68 struct mach_header {
  69     uint32_t magic;
  70     uint32_t cputype;
  71     uint32_t cpusubtype;
  72     uint32_t filetype;
  73     uint32_t ncmds;
  74     uint32_t sizeofcmds;
  75     uint32_t flags;
  76 } _packed;
  77
  78 #define MH_MAGIC 0xfeedface
  79 #define MH_CIGAM 0xcefaedfe
  80
  81 #define MH_EXECUTE    0x2
  82 #define MH_DYLIB      0x6
  83 #define MH_BUNDLE     0x8
  84 #define MH_DYLIB_STUB 0x9
  85
  86 struct load_command {
  87     uint32_t cmd;
  88     uint32_t cmdsize;
  89 } _packed;
  90
  91 #define LC_REQ_DYLD  0x80000000
  92
  93 #define LC_LOAD_DYLIB      0x0c
  94 #define LC_ID_DYLIB        0x0d
  95 #define LC_UUID            0x1b
  96 #define LC_CODE_SIGNATURE  0x1d
  97 #define LC_REEXPORT_DYLIB (0x1f | LC_REQ_DYLD)
  98
  99 struct dylib {
 100     uint32_t name;
 101     uint32_t timestamp;
 102     uint32_t current_version;
 103     uint32_t compatibility_version;
 104 } _packed;
 105
 106 struct dylib_command {
 107     uint32_t cmd;
 108     uint32_t cmdsize;
 109     struct dylib dylib;
 110 } _packed;
 111
 112 struct uuid_command {
 113     uint32_t cmd;
 114     uint32_t cmdsize;
 115     uint8_t uuid[16];
 116 } _packed;
 117
 118 struct linkedit_data_command {
 119     uint32_t cmd;
 120     uint32_t cmdsize;
 121     uint32_t dataoff;
 122     uint32_t datasize;
 123 } _packed;
 124
 125 uint16_t Swap_(uint16_t value) {
 126     return
 127         ((value >>  8) & 0x00ff) |
 128         ((value <<  8) & 0xff00);
 129 }
 130
 131 uint32_t Swap_(uint32_t value) {
 132     value = ((value >>  8) & 0x00ff00ff) |
 133             ((value <<  8) & 0xff00ff00);
 134     value = ((value >> 16) & 0x0000ffff) |
 135             ((value << 16) & 0xffff0000);
 136     return value;
 137 }
 138
 139 int16_t Swap_(int16_t value) {
 140     return Swap_(static_cast<uint16_t>(value));
 141 }
 142
 143 int32_t Swap_(int32_t value) {
 144     return Swap_(static_cast<uint32_t>(value));
 145 }
 146
 147 uint16_t Swap(uint16_t value) {
 148     return true ? Swap_(value) : value;
 149 }
 150
 151 uint32_t Swap(uint32_t value) {
 152     return true ? Swap_(value) : value;
 153 }
 154
 155 int16_t Swap(int16_t value) {
 156     return Swap(static_cast<uint16_t>(value));
 157 }
 158
 159 int32_t Swap(int32_t value) {
 160     return Swap(static_cast<uint32_t>(value));
 161 }
 162
 163 class Framework {
 164   private:
 165     void *base_;
 166     size_t size_;
 167     mach_header *mach_header_;
 168     bool swapped_;
 169
 170   public:
 171     uint16_t Swap(uint16_t value) const {
 172         return swapped_ ? Swap_(value) : value;
 173     }
 174
 175     uint32_t Swap(uint32_t value) const {
 176         return swapped_ ? Swap_(value) : value;
 177     }
 178
 179     int16_t Swap(int16_t value) const {
 180         return Swap(static_cast<uint16_t>(value));
 181     }
 182
 183     int32_t Swap(int32_t value) const {
 184         return Swap(static_cast<uint32_t>(value));
 185     }
 186
 187     Framework(const char *framework_path) :
 188         swapped_(false)
 189     {
 190         base_ = map(framework_path, 0, _not(size_t), &size_, false);
 191         fat_header *fat_header = reinterpret_cast<struct fat_header *>(base_);
 192
 193         if (Swap(fat_header->magic) == FAT_CIGAM) {
 194             swapped_ = !swapped_;
 195             goto fat;
 196         } else if (Swap(fat_header->magic) != FAT_MAGIC)
 197             mach_header_ = (mach_header *) base_;
 198         else fat: {
 199             size_t fat_narch = Swap(fat_header->nfat_arch);
 200             fat_arch *fat_arch = reinterpret_cast<struct fat_arch *>(fat_header + 1);
 201             size_t arch;
 202             for (arch = 0; arch != fat_narch; ++arch) {
 203                 uint32_t arch_offset = Swap(fat_arch->offset);
 204                 mach_header_ = (mach_header *) ((uint8_t *) base_ + arch_offset);
 205                 goto found;
 206                 ++fat_arch;
 207             }
 208
 209             _assert(false);
 210         }
 211
 212       found:
 213         if (Swap(mach_header_->magic) == MH_CIGAM)
 214             swapped_ = !swapped_;
 215         else _assert(Swap(mach_header_->magic) == MH_MAGIC);
 216
 217         _assert(
 218             Swap(mach_header_->filetype) == MH_EXECUTE ||
 219             Swap(mach_header_->filetype) == MH_DYLIB ||
 220             Swap(mach_header_->filetype) == MH_BUNDLE
 221         );
 222     }
 223
 224     struct mach_header *operator ->() const {
 225         return mach_header_;
 226     }
 227
 228     void *GetBase() {
 229         return base_;
 230     }
 231
 232     size_t GetSize() {
 233         return size_;
 234     }
 235
 236     std::vector<struct load_command *> GetLoadCommands() {
 237         std::vector<struct load_command *> load_commands;
 238
 239         struct load_command *load_command = reinterpret_cast<struct load_command *>(mach_header_ + 1);
 240         for (uint32_t cmd = 0; cmd != Swap(mach_header_->ncmds); ++cmd) {
 241             load_commands.push_back(load_command);
 242             load_command = (struct load_command *) ((uint8_t *) load_command + Swap(load_command->cmdsize));
 243         }
 244
 245         return load_commands;
 246     }
 247 };
 248
 249 #define CSMAGIC_CODEDIRECTORY      0xfade0c02
 250 #define CSMAGIC_EMBEDDED_SIGNATURE 0xfade0cc0
 251 #define CSMAGIC_ENTITLEMENTS       0xfade7171
 252
 253 #define CSSLOT_CODEDIRECTORY 0
 254 #define CSSLOT_REQUIREMENTS  2
 255 #define CSSLOT_ENTITLEMENTS  5
 256
 257 struct BlobIndex {
 258     uint32_t type;
 259     uint32_t offset;
 260 } _packed;
 261
 262 struct Blob {
 263     uint32_t magic;
 264     uint32_t length;
 265 } _packed;
 266
 267 struct SuperBlob {
 268     struct Blob blob;
 269     uint32_t count;
 270     struct BlobIndex index[];
 271 } _packed;
 272
 273 struct CodeDirectory {
 274     struct Blob blob;
 275     uint32_t version;
 276     uint32_t flags;
 277     uint32_t hashOffset;
 278     uint32_t identOffset;
 279     uint32_t nSpecialSlots;
 280     uint32_t nCodeSlots;
 281     uint32_t codeLimit;
 282     uint8_t hashSize;
 283     uint8_t hashType;
 284     uint8_t spare1;
 285     uint8_t pageSize;
 286     uint32_t spare2;
 287 } _packed;
 288
 289 extern "C" uint32_t hash(uint8_t *k, uint32_t length, uint32_t initval);
 290
 291 #define CODESIGN_ALLOCATE "arm-apple-darwin9-codesign_allocate"
 292
 293 void sha1(uint8_t *hash, uint8_t *data, size_t size) {
 294     SHA1Context context;
 295     SHA1Reset(&context);
 296     SHA1Input(&context, data, size);
 297     SHA1Result(&context, hash);
 298 }
 299
 300 int main(int argc, const char *argv[]) {
 301     bool flag_R(false);
 302     bool flag_t(false);
 303     bool flag_p(false);
 304     bool flag_u(false);
 305
 306     bool flag_T(false);
 307
 308     bool flag_S(false);
 309     bool flag_s(false);
 310
 311     bool timeh(false);
 312     uint32_t timev(0);
 313
 314     const void *xmld(NULL);
 315     size_t xmls(0);
 316
 317     std::vector<std::string> files;
 318
 319     _assert(argc != 0);
 320     for (int argi(1); argi != argc; ++argi)
 321         if (argv[argi][0] != '-')
 322             files.push_back(argv[argi]);
 323         else switch (argv[argi][1]) {
 324             case 'R': flag_R = true; break;
 325             case 't': flag_t = true; break;
 326             case 'u': flag_u = true; break;
 327             case 'p': flag_p = true; break;
 328
 329             case 's':
 330                 _assert(!flag_S);
 331                 flag_s = true;
 332             break;
 333
 334             case 'S':
 335                 _assert(!flag_s);
 336                 flag_S = true;
 337                 if (argv[argi][2] != '\0') {
 338                     const char *xml = argv[argi] + 2;
 339                     xmld = map(xml, 0, _not(size_t), &xmls, true);
 340                 }
 341             break;
 342
 343             case 'T': {
 344                 flag_T = true;
 345                 if (argv[argi][2] == '-')
 346                     timeh = true;
 347                 else {
 348                     char *arge;
 349                     timev = strtoul(argv[argi] + 2, &arge, 0);
 350                     _assert(arge == argv[argi] + strlen(argv[argi]));
 351                 }
 352             } break;
 353
 354             default:
 355                 goto usage;
 356             break;
 357         }
 358
 359     if (files.empty()) usage: {
 360         exit(0);
 361     }
 362
 363     size_t filei(0), filee(0);
 364     _foreach (file, files) try {
 365         const char *path(file->c_str());
 366         const char *base = strrchr(path, '/');
 367         char *temp(NULL), *dir;
 368         mode_t mode = 0;
 369
 370         if (base != NULL)
 371             dir = strndup_(path, base++ - path + 1);
 372         else {
 373             dir = strdup("");
 374             base = path;
 375         }
 376
 377         if (flag_S) {
 378             asprintf(&temp, "%s.%s.cs", dir, base);
 379             const char *allocate = getenv("CODESIGN_ALLOCATE");
 380             if (allocate == NULL)
 381                 allocate = "codesign_allocate";
 382
 383             size_t size = _not(size_t);
 384             const char *arch; {
 385                 Framework framework(path);
 386                 _foreach (load_command, framework.GetLoadCommands()) {
 387                     uint32_t cmd(framework.Swap((*load_command)->cmd));
 388                     if (cmd == LC_CODE_SIGNATURE) {
 389                         struct linkedit_data_command *signature = reinterpret_cast<struct linkedit_data_command *>(*load_command);
 390                         size = framework.Swap(signature->dataoff);
 391                         _assert(size < framework.GetSize());
 392                         break;
 393                     }
 394                 }
 395
 396                 if (size == _not(size_t))
 397                     size = framework.GetSize();
 398
 399                 switch (framework->cputype) {
 400                     case 12: switch (framework->cpusubtype) {
 401                         case 0: arch = "arm"; break;
 402                         case 6: arch = "armv6"; break;
 403                         default: arch = NULL; break;
 404                     } break;
 405
 406                     default: arch = NULL; break;
 407                 }
 408             }
 409
 410             _assert(arch != NULL);
 411
 412             pid_t pid = fork();
 413             _syscall(pid);
 414             if (pid == 0) {
 415                 char *ssize;
 416                 asprintf(&ssize, "%u", (sizeof(struct SuperBlob) + 2 * sizeof(struct BlobIndex) + sizeof(struct CodeDirectory) + strlen(base) + 1 + ((xmld == NULL ? CSSLOT_REQUIREMENTS : CSSLOT_ENTITLEMENTS) + (size + 0x1000 - 1) / 0x1000) * 0x14 + 0xc + (xmld == NULL ? 0 : 0x10 + xmls) + 15) / 16 * 16);
 417                 //printf("%s -i %s -a %s %s -o %s\n", allocate, path, arch, ssize, temp);
 418                 execlp(allocate, allocate, "-i", path, "-a", arch, ssize, "-o", temp, NULL);
 419                 _assert(false);
 420             }
 421
 422             int status;
 423             _syscall(waitpid(pid, &status, 0));
 424             _assert(WIFEXITED(status));
 425             _assert(WEXITSTATUS(status) == 0);
 426         }
 427
 428         Framework framework(temp == NULL ? path : temp);
 429         struct linkedit_data_command *signature(NULL);
 430
 431         if (flag_p)
 432             printf("path%zu='%s'\n", filei, file->c_str());
 433
 434         _foreach (load_command, framework.GetLoadCommands()) {
 435             uint32_t cmd(framework.Swap((*load_command)->cmd));
 436
 437             if (flag_R && cmd == LC_REEXPORT_DYLIB)
 438                 (*load_command)->cmd = framework.Swap(LC_LOAD_DYLIB);
 439             else if (cmd == LC_CODE_SIGNATURE)
 440                 signature = reinterpret_cast<struct linkedit_data_command *>(*load_command);
 441             else if (cmd == LC_UUID) {
 442                 volatile struct uuid_command *uuid_command(reinterpret_cast<struct uuid_command *>(*load_command));
 443
 444                 if (flag_u) {
 445                     printf("uuid%zu=%.2x%.2x%.2x%.2x-%.2x%.2x-%.2x%.2x-%.2x%.2x-%.2x%.2x%.2x%.2x%.2x%.2x\n", filei,
 446                         uuid_command->uuid[ 0], uuid_command->uuid[ 1], uuid_command->uuid[ 2], uuid_command->uuid[ 3],
 447                         uuid_command->uuid[ 4], uuid_command->uuid[ 5], uuid_command->uuid[ 6], uuid_command->uuid[ 7],
 448                         uuid_command->uuid[ 8], uuid_command->uuid[ 9], uuid_command->uuid[10], uuid_command->uuid[11],
 449                         uuid_command->uuid[12], uuid_command->uuid[13], uuid_command->uuid[14], uuid_command->uuid[15]
 450                     );
 451                 }
 452             } else if (cmd == LC_ID_DYLIB) {
 453                 volatile struct dylib_command *dylib_command(reinterpret_cast<struct dylib_command *>(*load_command));
 454
 455                 if (flag_t)
 456                     printf("time%zu=0x%.8x\n", filei, framework.Swap(dylib_command->dylib.timestamp));
 457
 458                 if (flag_T) {
 459                     uint32_t timed;
 460
 461                     if (!timeh)
 462                         timed = timev;
 463                     else {
 464                         dylib_command->dylib.timestamp = 0;
 465                         timed = hash(reinterpret_cast<uint8_t *>(framework.GetBase()), framework.GetSize(), timev);
 466                     }
 467
 468                     dylib_command->dylib.timestamp = framework.Swap(timed);
 469                 }
 470             }
 471         }
 472
 473         if (flag_s) {
 474             _assert(signature != NULL);
 475
 476             uint32_t data = framework.Swap(signature->dataoff);
 477             uint32_t size = framework.Swap(signature->datasize);
 478
 479             uint8_t *top = reinterpret_cast<uint8_t *>(framework.GetBase());
 480             uint8_t *blob = top + data;
 481             struct SuperBlob *super = reinterpret_cast<struct SuperBlob *>(blob);
 482
 483             for (size_t index(0); index != Swap(super->count); ++index)
 484                 if (Swap(super->index[index].type) == CSSLOT_CODEDIRECTORY) {
 485                     uint32_t begin = Swap(super->index[index].offset);
 486                     struct CodeDirectory *directory = reinterpret_cast<struct CodeDirectory *>(blob + begin);
 487
 488                     uint8_t (*hashes)[20] = reinterpret_cast<uint8_t (*)[20]>(blob + begin + Swap(directory->hashOffset));
 489                     uint32_t pages = Swap(directory->nCodeSlots);
 490
 491                     if (pages != 1)
 492                         for (size_t i = 0; i != pages - 1; ++i)
 493                             sha1(hashes[i], top + 0x1000 * i, 0x1000);
 494                     if (pages != 0)
 495                         sha1(hashes[pages - 1], top + 0x1000 * (pages - 1), data % 0x1000);
 496                 }
 497         }
 498
 499         if (flag_S) {
 500             _assert(signature != NULL);
 501
 502             uint32_t data = framework.Swap(signature->dataoff);
 503             uint32_t size = framework.Swap(signature->datasize);
 504
 505             uint8_t *top = reinterpret_cast<uint8_t *>(framework.GetBase());
 506             uint8_t *blob = top + data;
 507             struct SuperBlob *super = reinterpret_cast<struct SuperBlob *>(blob);
 508             super->blob.magic = Swap(CSMAGIC_EMBEDDED_SIGNATURE);
 509
 510             uint32_t count = xmld == NULL ? 2 : 3;
 511             uint32_t offset = sizeof(struct SuperBlob) + count * sizeof(struct BlobIndex);
 512
 513             super->index[0].type = Swap(CSSLOT_CODEDIRECTORY);
 514             super->index[0].offset = Swap(offset);
 515
 516             uint32_t begin = offset;
 517             struct CodeDirectory *directory = reinterpret_cast<struct CodeDirectory *>(blob + begin);
 518             offset += sizeof(struct CodeDirectory);
 519
 520             directory->blob.magic = Swap(CSMAGIC_CODEDIRECTORY);
 521             directory->version = Swap(0x00020001);
 522             directory->flags = Swap(0);
 523             directory->codeLimit = Swap(data);
 524             directory->hashSize = 0x14;
 525             directory->hashType = 0x01;
 526             directory->spare1 = 0x00;
 527             directory->pageSize = 0x0c;
 528             directory->spare2 = Swap(0);
 529
 530             directory->identOffset = Swap(offset - begin);
 531             strcpy(reinterpret_cast<char *>(blob + offset), base);
 532             offset += strlen(base) + 1;
 533
 534             uint32_t special = xmld == NULL ? CSSLOT_REQUIREMENTS : CSSLOT_ENTITLEMENTS;
 535             directory->nSpecialSlots = Swap(special);
 536
 537             uint8_t (*hashes)[20] = reinterpret_cast<uint8_t (*)[20]>(blob + offset);
 538             memset(hashes, 0, sizeof(*hashes) * special);
 539
 540             offset += sizeof(*hashes) * special;
 541             hashes += special;
 542
 543             uint32_t pages = (data + 0x1000 - 1) / 0x1000;
 544             directory->nCodeSlots = Swap(pages);
 545
 546             if (pages != 1)
 547                 for (size_t i = 0; i != pages - 1; ++i)
 548                     sha1(hashes[i], top + 0x1000 * i, 0x1000);
 549             if (pages != 0)
 550                 sha1(hashes[pages - 1], top + 0x1000 * (pages - 1), data % 0x1000);
 551
 552             directory->hashOffset = Swap(offset - begin);
 553             offset += sizeof(*hashes) * pages;
 554             directory->blob.length = Swap(offset - begin);
 555
 556             super->index[1].type = Swap(CSSLOT_REQUIREMENTS);
 557             super->index[1].offset = Swap(offset);
 558
 559             memcpy(blob + offset, "\xfa\xde\x0c\x01\x00\x00\x00\x0c\x00\x00\x00\x00", 0xc);
 560             offset += 0xc;
 561
 562             if (xmld != NULL) {
 563                 super->index[2].type = Swap(CSSLOT_ENTITLEMENTS);
 564                 super->index[2].offset = Swap(offset);
 565
 566                 uint32_t begin = offset;
 567                 struct Blob *entitlements = reinterpret_cast<struct Blob *>(blob + begin);
 568                 offset += sizeof(struct Blob);
 569
 570                 memcpy(blob + offset, xmld, xmls);
 571                 offset += xmls;
 572
 573                 entitlements->magic = Swap(CSMAGIC_ENTITLEMENTS);
 574                 entitlements->length = Swap(offset - begin);
 575             }
 576
 577             for (size_t index(0); index != count; ++index) {
 578                 uint32_t type = Swap(super->index[index].type);
 579                 if (type != 0 && type <= special) {
 580                     uint32_t offset = Swap(super->index[index].offset);
 581                     struct Blob *local = (struct Blob *) (blob + offset);
 582                     sha1((uint8_t *) (hashes - type), (uint8_t *) local, Swap(local->length));
 583                 }
 584             }
 585
 586             super->count = Swap(count);
 587             super->blob.length = Swap(offset);
 588
 589             if (offset > size) {
 590                 fprintf(stderr, "offset (%zu) > size (%zu)\n", offset, size);
 591                 _assert(false);
 592             } //else fprintf(stderr, "offset (%zu) <= size (%zu)\n", offset, size);
 593
 594             memset(blob + offset, 0, size - offset);
 595         }
 596
 597         if (temp) {
 598             struct stat info;
 599             _syscall(stat(path, &info));
 600             _syscall(chown(temp, info.st_uid, info.st_gid));
 601             _syscall(chmod(temp, info.st_mode));
 602             _syscall(unlink(path));
 603             _syscall(rename(temp, path));
 604             free(temp);
 605         }
 606
 607         free(dir);
 608         ++filei;
 609     } catch (const char *) {
 610         ++filee;
 611         ++filei;
 612     }
 613
 614     return filee;
 615 }