OSX/libsecurity_codesigning/lib/signer.cpp

   1 /*
   2  * Copyright (c) 2006-2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 //
  25 // signer - Signing operation supervisor and controller
  26 //
  27 #include "signer.h"
  28 #include "resources.h"
  29 #include "signerutils.h"
  30 #include "SecCodeSigner.h"
  31 #include <Security/SecIdentity.h>
  32 #include <Security/CMSEncoder.h>
  33 #include <Security/CMSPrivate.h>
  34 #include <Security/CSCommonPriv.h>
  35 #include <CoreFoundation/CFBundlePriv.h>
  36 #include "resources.h"
  37 #include "machorep.h"
  38 #include "reqparser.h"
  39 #include "reqdumper.h"
  40 #include "csutilities.h"
  41 #include <security_utilities/unix++.h>
  42 #include <security_utilities/unixchild.h>
  43 #include <security_utilities/cfmunge.h>
  44 #include <security_utilities/dispatch.h>
  45 #include <IOKit/storage/IOStorageDeviceCharacteristics.h>
  46
  47 namespace Security {
  48 namespace CodeSigning {
  49
  50
  51 //
  52 // Sign some code.
  53 //
  54 void SecCodeSigner::Signer::sign(SecCSFlags flags)
  55 {
  56         rep = code->diskRep()->base();
  57         this->prepare(flags);
  58
  59         PreSigningContext context(*this);
  60
  61         considerTeamID(context);
  62
  63         if (Universal *fat = state.mNoMachO ? NULL : rep->mainExecutableImage()) {
  64                 signMachO(fat, context);
  65         } else {
  66                 signArchitectureAgnostic(context);
  67         }
  68 }
  69
  70
  71 void SecCodeSigner::Signer::considerTeamID(const PreSigningContext& context)
  72 {
  73         /* If an explicit teamID was passed in it must be
  74          the same as what came from the cert */
  75         std::string teamIDFromCert = state.getTeamIDFromSigner(context.certs);
  76
  77         if (state.mPreserveMetadata & kSecCodeSignerPreserveTeamIdentifier) {
  78                 /* If preserving the team identifier, teamID is set previously when the
  79                  code object is still available */
  80                 if (!teamIDFromCert.empty() && teamID != teamIDFromCert)
  81                         MacOSError::throwMe(errSecCSInvalidFlags);
  82         } else {
  83                 if (teamIDFromCert.empty()) {
  84                         /* state.mTeamID is an explicitly passed teamID */
  85                         teamID = state.mTeamID;
  86                 } else if (state.mTeamID.empty() || (state.mTeamID == teamIDFromCert)) {
  87                         /* If there was no explicit team ID set, or the explicit team ID matches
  88                          what is in the cert, use the team ID from the certificate */
  89                         teamID = teamIDFromCert;
  90                 } else {
  91                         /* The caller passed in an explicit team ID that does not match what is
  92                          in the signing cert, which is an invalid usage */
  93                         MacOSError::throwMe(errSecCSInvalidFlags);
  94                 }
  95         }
  96 }
  97
  98
  99 //
 100 // Remove any existing code signature from code
 101 //
 102 void SecCodeSigner::Signer::remove(SecCSFlags flags)
 103 {
 104         // can't remove a detached signature
 105         if (state.mDetached)
 106                 MacOSError::throwMe(errSecCSNotSupported);
 107
 108         rep = code->diskRep();
 109         if (Universal *fat = state.mNoMachO ? NULL : rep->mainExecutableImage()) {
 110                 // architecture-sensitive removal
 111                 MachOEditor editor(rep->writer(), *fat, digestAlgorithms(), rep->mainExecutablePath());
 112                 editor.allocate();              // create copy
 113                 editor.commit();                // commit change
 114         } else {
 115                 // architecture-agnostic removal
 116                 RefPointer<DiskRep::Writer> writer = rep->writer();
 117                 writer->remove();
 118                 writer->flush();
 119         }
 120 }
 121
 122
 123 //
 124 // Contemplate the object-to-be-signed and set up the Signer state accordingly.
 125 //
 126 void SecCodeSigner::Signer::prepare(SecCSFlags flags)
 127 {
 128         // make sure the rep passes strict validation
 129         if (strict)
 130                 rep->strictValidate(NULL, MacOSErrorSet(), flags | (kSecCSQuickCheck|kSecCSRestrictSidebandData));
 131
 132         // initialize progress/cancellation state
 133         code->prepareProgress(0);                       // totally fake workload - we don't know how many files we'll encounter
 134
 135         // get the Info.plist out of the rep for some creative defaulting
 136         CFRef<CFDictionaryRef> infoDict;
 137         if (CFRef<CFDataRef> infoData = rep->component(cdInfoSlot))
 138                 infoDict.take(makeCFDictionaryFrom(infoData));
 139
 140         uint32_t inherit = code->isSigned() ? state.mPreserveMetadata : 0;
 141
 142         // work out the canonical identifier
 143         identifier = state.mIdentifier;
 144         if (identifier.empty() && (inherit & kSecCodeSignerPreserveIdentifier))
 145                 identifier = code->identifier();
 146         if (identifier.empty()) {
 147                 identifier = rep->recommendedIdentifier(*this);
 148                 if (identifier.find('.') == string::npos)
 149                         identifier = state.mIdentifierPrefix + identifier;
 150                 if (identifier.find('.') == string::npos && isAdhoc())
 151                         identifier = identifier + "-" + uniqueName();
 152                 secinfo("signer", "using default identifier=%s", identifier.c_str());
 153         } else
 154                 secinfo("signer", "using explicit identifier=%s", identifier.c_str());
 155
 156         teamID = state.mTeamID;
 157         if (teamID.empty() && (inherit & kSecCodeSignerPreserveTeamIdentifier)) {
 158                 const char *c_id = code->teamID();
 159                 if (c_id)
 160                         teamID = c_id;
 161         }
 162
 163         // Digest algorithms: explicit or preserved. Subject to diskRep defaults or final default later.
 164         hashAlgorithms = state.mDigestAlgorithms;
 165         if (hashAlgorithms.empty() && (inherit & kSecCodeSignerPreserveDigestAlgorithm))
 166                 hashAlgorithms = code->hashAlgorithms();
 167
 168         entitlements = state.mEntitlementData;
 169         if (!entitlements && (inherit & kSecCodeSignerPreserveEntitlements))
 170                 entitlements = code->component(cdEntitlementSlot);
 171
 172         // work out the CodeDirectory flags word
 173         bool haveCdFlags = false;
 174         if (!haveCdFlags && state.mCdFlagsGiven) {
 175                 cdFlags = state.mCdFlags;
 176                 secinfo("signer", "using explicit cdFlags=0x%x", cdFlags);
 177                 haveCdFlags = true;
 178         }
 179         if (!haveCdFlags) {
 180                 cdFlags = 0;
 181                 if (infoDict)
 182                         if (CFTypeRef csflags = CFDictionaryGetValue(infoDict, CFSTR("CSFlags"))) {
 183                                 if (CFGetTypeID(csflags) == CFNumberGetTypeID()) {
 184                                         cdFlags = cfNumber<uint32_t>(CFNumberRef(csflags));
 185                                         secinfo("signer", "using numeric cdFlags=0x%x from Info.plist", cdFlags);
 186                                 } else if (CFGetTypeID(csflags) == CFStringGetTypeID()) {
 187                                         cdFlags = cdTextFlags(cfString(CFStringRef(csflags)));
 188                                         secinfo("signer", "using text cdFlags=0x%x from Info.plist", cdFlags);
 189                                 } else
 190                                         MacOSError::throwMe(errSecCSBadDictionaryFormat);
 191                                 haveCdFlags = true;
 192                         }
 193         }
 194         if (!haveCdFlags && (inherit & kSecCodeSignerPreserveFlags)) {
 195                 cdFlags = code->codeDirectory(false)->flags & ~kSecCodeSignatureAdhoc;
 196                 secinfo("signer", "using inherited cdFlags=0x%x", cdFlags);
 197                 haveCdFlags = true;
 198         }
 199         if (!haveCdFlags)
 200                 cdFlags = 0;
 201         if (state.mSigner == SecIdentityRef(kCFNull))   // ad-hoc signing requested...
 202                 cdFlags |= kSecCodeSignatureAdhoc;      // ... so note that
 203
 204         // prepare the internal requirements input
 205         if (state.mRequirements) {
 206                 if (CFGetTypeID(state.mRequirements) == CFDataGetTypeID()) {            // binary form
 207                         const Requirements *rp = (const Requirements *)CFDataGetBytePtr(state.mRequirements.as<CFDataRef>());
 208                         if (!rp->validateBlob())
 209                                 MacOSError::throwMe(errSecCSReqInvalid);
 210                         requirements = rp->clone();
 211                 } else if (CFGetTypeID(state.mRequirements) == CFStringGetTypeID()) { // text form
 212                         CFRef<CFMutableStringRef> reqText = CFStringCreateMutableCopy(NULL, 0, state.mRequirements.as<CFStringRef>());
 213                         // substitute $ variable tokens
 214                         CFRange range = { 0, CFStringGetLength(reqText) };
 215                         CFStringFindAndReplace(reqText, CFSTR("$self.identifier"), CFTempString(identifier), range, 0);
 216                         requirements = parseRequirements(cfString(reqText));
 217                 } else
 218                         MacOSError::throwMe(errSecCSInvalidObjectRef);
 219         } else if (inherit & kSecCodeSignerPreserveRequirements)
 220                 if (const Requirements *rp = code->internalRequirements())
 221                         requirements = rp->clone();
 222
 223         // prepare the resource directory, if any
 224         string rpath = rep->resourcesRootPath();
 225         string rrpath;
 226         CFCopyRef<CFDictionaryRef> resourceRules;
 227         if (!rpath.empty()) {
 228                 // explicitly given resource rules always win
 229                 resourceRules = state.mResourceRules;
 230
 231                 // inherited rules come next (overriding embedded ones!)
 232                 if (!resourceRules && (inherit & kSecCodeSignerPreserveResourceRules))
 233                         if (CFDictionaryRef oldRules = code->resourceDictionary(false))
 234                                 resourceRules = oldRules;
 235
 236                 // embedded resource rules come next
 237                 if (!resourceRules && infoDict)
 238                         if (CFTypeRef spec = CFDictionaryGetValue(infoDict, _kCFBundleResourceSpecificationKey)) {
 239                                 if (CFGetTypeID(spec) == CFStringGetTypeID())
 240                                         if (CFRef<CFDataRef> data = cfLoadFile(rpath + "/" + cfString(CFStringRef(spec))))
 241                                                 if (CFDictionaryRef dict = makeCFDictionaryFrom(data))
 242                                                         resourceRules.take(dict);
 243                                 if (!resourceRules)     // embedded rules present but unacceptable
 244                                         MacOSError::throwMe(errSecCSResourceRulesInvalid);
 245                         }
 246
 247                 // if we got one from anywhere (but the defaults), sanity-check it
 248                 if (resourceRules) {
 249                         CFTypeRef rules = CFDictionaryGetValue(resourceRules, CFSTR("rules"));
 250                         if (!rules || CFGetTypeID(rules) != CFDictionaryGetTypeID())
 251                                 MacOSError::throwMe(errSecCSResourceRulesInvalid);
 252                 }
 253
 254                 // finally, ask the DiskRep for its default
 255                 if (!resourceRules)
 256                         resourceRules.take(rep->defaultResourceRules(*this));
 257
 258                 // resource root can optionally be the canonical bundle path,
 259                 // but sealed resource paths are always relative to rpath
 260                 rrpath = rpath;
 261                 if (signingFlags() & kSecCSSignBundleRoot)
 262                         rrpath = cfStringRelease(rep->copyCanonicalPath());
 263         }
 264
 265         // screen and set the signing time
 266         if (state.mSigningTime == CFDateRef(kCFNull)) {
 267                 emitSigningTime = false;                // no time at all
 268         } else if (!state.mSigningTime) {
 269                 emitSigningTime = true;
 270                 signingTime = 0;                        // wall clock, established later
 271         } else {
 272                 CFAbsoluteTime time = CFDateGetAbsoluteTime(state.mSigningTime);
 273                 if (time > CFAbsoluteTimeGetCurrent())  // not allowed to post-date a signature
 274                         MacOSError::throwMe(errSecCSBadDictionaryFormat);
 275                 emitSigningTime = true;
 276                 signingTime = time;
 277         }
 278
 279         pagesize = state.mPageSize ? cfNumber<size_t>(state.mPageSize) : rep->pageSize(*this);
 280
 281         // Allow the DiskRep to modify the signing parameters. This sees explicit and inherited values but not defaults.
 282         rep->prepareForSigning(*this);
 283
 284         // apply some defaults after diskRep intervention
 285         if (hashAlgorithms.empty()) {   // default to SHA256 + SHA-1
 286                 hashAlgorithms.insert(kSecCodeSignatureHashSHA1);
 287                 hashAlgorithms.insert(kSecCodeSignatureHashSHA256);
 288         }
 289
 290         // build the resource directory (once and for all, using the digests determined above)
 291         if (!rpath.empty()) {
 292                 buildResources(rrpath, rpath, resourceRules);
 293         }
 294 }
 295
 296
 297 //
 298 // Collect the resource seal for a program.
 299 // This includes both sealed resources and information about nested code.
 300 //
 301 void SecCodeSigner::Signer::buildResources(std::string root, std::string relBase, CFDictionaryRef rulesDict)
 302 {
 303         typedef ResourceBuilder::Rule Rule;
 304
 305         secinfo("codesign", "start building resource directory");
 306         __block CFRef<CFMutableDictionaryRef> result = makeCFMutableDictionary();
 307
 308         CFDictionaryRef rules = cfget<CFDictionaryRef>(rulesDict, "rules");
 309         assert(rules);
 310
 311         if (this->state.mLimitedAsync == NULL) {
 312                 this->state.mLimitedAsync =
 313                         /* rdar://problem/20299541: Async workers (i.e. parallelization) are currently
 314                          * turned off, because the paths for signing code are not ready for it yet. */
 315                         // new LimitedAsync(rep->fd().mediumType() == kIOPropertyMediumTypeSolidStateKey);
 316                         new LimitedAsync(false);
 317         }
 318
 319         CFDictionaryRef files2 = NULL;
 320         if (!(signingFlags() & kSecCSSignV1)) {
 321                 CFCopyRef<CFDictionaryRef> rules2 = cfget<CFDictionaryRef>(rulesDict, "rules2");
 322                 if (!rules2) {
 323                         // Clone V1 rules and add default nesting rules at weight 0 (overridden by anything in rules).
 324                         // V1 rules typically do not cover these places so we'll prevail, but if they do, we defer to them.
 325                         rules2 = cfmake<CFDictionaryRef>("{+%O"
 326                                 "'^(Frameworks|SharedFrameworks|PlugIns|Plug-ins|XPCServices|Helpers|MacOS|Library/(Automator|Spotlight|LoginItems))/' = {nested=#T, weight=0}" // exclude dynamic repositories
 327                         "}", rules);
 328                 }
 329
 330                 Dispatch::Group group;
 331                 Dispatch::Group &groupRef = group;  // (into block)
 332
 333                 // build the modern (V2) resource seal
 334                 __block CFRef<CFMutableDictionaryRef> files = makeCFMutableDictionary();
 335                 CFMutableDictionaryRef filesRef = files.get();  // (into block)
 336                 ResourceBuilder resourceBuilder(root, relBase, rules2, strict, MacOSErrorSet());
 337                 ResourceBuilder &resources = resourceBuilder;   // (into block)
 338                 rep->adjustResources(resources);
 339
 340                 resources.scan(^(FTSENT *ent, uint32_t ruleFlags, const std::string relpath, Rule *rule) {
 341                         bool isSymlink = (ent->fts_info == FTS_SL);
 342                         const std::string path(ent->fts_path);
 343                         const std::string accpath(ent->fts_accpath);
 344                         this->state.mLimitedAsync->perform(groupRef, ^{
 345                                 CFRef<CFMutableDictionaryRef> seal;
 346                                 if (ruleFlags & ResourceBuilder::nested) {
 347                                         seal.take(signNested(path, relpath));
 348                                 } else if (isSymlink) {
 349                                         char target[PATH_MAX];
 350                                         ssize_t len = ::readlink(accpath.c_str(), target, sizeof(target)-1);
 351                                         if (len < 0)
 352                                                 UnixError::check(-1);
 353                                         target[len] = '\0';
 354                                         seal.take(cfmake<CFMutableDictionaryRef>("{symlink=%s}", target));
 355                                 } else {
 356                                         seal.take(resources.hashFile(accpath.c_str(), digestAlgorithms(), signingFlags() & kSecCSSignStrictPreflight));
 357                                 }
 358                                 if (ruleFlags & ResourceBuilder::optional)
 359                                         CFDictionaryAddValue(seal, CFSTR("optional"), kCFBooleanTrue);
 360                                 CFTypeRef hash;
 361                                 StLock<Mutex> _(resourceLock);
 362                                 if ((hash = CFDictionaryGetValue(seal, CFSTR("hash"))) && CFDictionaryGetCount(seal) == 1) // simple form
 363                                         CFDictionaryAddValue(filesRef, CFTempString(relpath).get(), hash);
 364                                 else
 365                                         CFDictionaryAddValue(filesRef, CFTempString(relpath).get(), seal.get());
 366                                 code->reportProgress();
 367                         });
 368                 });
 369                 group.wait();
 370                 CFDictionaryAddValue(result, CFSTR("rules2"), resourceBuilder.rules());
 371                 files2 = files;
 372                 CFDictionaryAddValue(result, CFSTR("files2"), files2);
 373         }
 374
 375         CFDictionaryAddValue(result, CFSTR("rules"), rules);    // preserve V1 rules in any case
 376         if (!(signingFlags() & kSecCSSignNoV1)) {
 377                 // build the legacy (V1) resource seal
 378                 __block CFRef<CFMutableDictionaryRef> files = makeCFMutableDictionary();
 379                 ResourceBuilder resourceBuilder(root, relBase, rules, strict, MacOSErrorSet());
 380                 ResourceBuilder &resources = resourceBuilder;
 381                 rep->adjustResources(resources);        // DiskRep-specific adjustments
 382                 resources.scan(^(FTSENT *ent, uint32_t ruleFlags, std::string relpath, Rule *rule) {
 383                         if (ent->fts_info == FTS_F) {
 384                                 CFRef<CFDataRef> hash;
 385                                 if (files2)     // try to get the hash from a previously-made version
 386                                         if (CFTypeRef seal = CFDictionaryGetValue(files2, CFTempString(relpath))) {
 387                                                 if (CFGetTypeID(seal) == CFDataGetTypeID())
 388                                                         hash = CFDataRef(seal);
 389                                                 else
 390                                                         hash = CFDataRef(CFDictionaryGetValue(CFDictionaryRef(seal), CFSTR("hash")));
 391                                         }
 392                                 if (!hash)
 393                                         hash.take(resources.hashFile(ent->fts_accpath, kSecCodeSignatureHashSHA1));
 394                                 if (ruleFlags == 0) {   // default case - plain hash
 395                                         cfadd(files, "{%s=%O}", relpath.c_str(), hash.get());
 396                                         secinfo("csresource", "%s added simple (rule %p)", relpath.c_str(), rule);
 397                                 } else {        // more complicated - use a sub-dictionary
 398                                         cfadd(files, "{%s={hash=%O,optional=%B}}",
 399                                                 relpath.c_str(), hash.get(), ruleFlags & ResourceBuilder::optional);
 400                                         secinfo("csresource", "%s added complex (rule %p)", relpath.c_str(), rule);
 401                                 }
 402                         }
 403                 });
 404                 CFDictionaryAddValue(result, CFSTR("files"), files.get());
 405         }
 406
 407         resourceDirectory = result.get();
 408         resourceDictData.take(makeCFData(resourceDirectory.get()));
 409 }
 410
 411
 412 //
 413 // Deal with one piece of nested code
 414 //
 415 CFMutableDictionaryRef SecCodeSigner::Signer::signNested(const std::string &path, const std::string &relpath)
 416 {
 417         // sign nested code and collect nesting information
 418         try {
 419                 SecPointer<SecStaticCode> code = new SecStaticCode(DiskRep::bestGuess(path));
 420                 if (signingFlags() & kSecCSSignNestedCode)
 421                         this->state.sign(code, signingFlags());
 422                 std::string dr = Dumper::dump(code->designatedRequirement());
 423                 if (CFDataRef hash = code->cdHash())
 424                         return cfmake<CFMutableDictionaryRef>("{requirement=%s,cdhash=%O}",
 425                                 Dumper::dump(code->designatedRequirement()).c_str(),
 426                                 hash);
 427                 MacOSError::throwMe(errSecCSUnsigned);
 428         } catch (const CommonError &err) {
 429                 CSError::throwMe(err.osStatus(), kSecCFErrorPath, CFTempURL(relpath, false, this->code->resourceBase()));
 430         }
 431 }
 432
 433
 434 //
 435 // Sign a Mach-O binary, using liberal dollops of that special Mach-O magic sauce.
 436 // Note that this will deal just fine with non-fat Mach-O binaries, but it will
 437 // treat them as architectural binaries containing (only) one architecture - that
 438 // interpretation is courtesy of the Universal/MachO support classes.
 439 //
 440 void SecCodeSigner::Signer::signMachO(Universal *fat, const Requirement::Context &context)
 441 {
 442         // Mach-O executable at the core - perform multi-architecture signing
 443         RefPointer<DiskRep::Writer> writer = rep->writer();
 444         auto_ptr<ArchEditor> editor(state.mDetached
 445                 ? static_cast<ArchEditor *>(new BlobEditor(*fat, *this))
 446                 : new MachOEditor(writer, *fat, this->digestAlgorithms(), rep->mainExecutablePath()));
 447         assert(editor->count() > 0);
 448         if (!editor->attribute(writerNoGlobal)) // can store architecture-common components
 449                 populate(*editor);
 450
 451         // pass 1: prepare signature blobs and calculate sizes
 452         for (MachOEditor::Iterator it = editor->begin(); it != editor->end(); ++it) {
 453                 MachOEditor::Arch &arch = *it->second;
 454                 arch.source.reset(fat->architecture(it->first));
 455
 456                 // library validation is not compatible with i386
 457                 if (arch.architecture.cpuType() == CPU_TYPE_I386) {
 458                         if (cdFlags & kSecCodeSignatureLibraryValidation) {
 459                                 MacOSError::throwMe(errSecCSBadLVArch);
 460                         }
 461                 }
 462
 463                 arch.ireqs(requirements, rep->defaultRequirements(&arch.architecture, *this), context);
 464                 if (editor->attribute(writerNoGlobal))  // can't store globally, add per-arch
 465                         populate(arch);
 466                 for (auto type = digestAlgorithms().begin(); type != digestAlgorithms().end(); ++type) {
 467                         arch.eachDigest(^(CodeDirectory::Builder& builder) {
 468                                 populate(builder, arch, arch.ireqs,
 469                                                  arch.source->offset(), arch.source->signingExtent(), unsigned(digestAlgorithms().size()-1));
 470                         });
 471                 }
 472
 473                 // add identification blob (made from this architecture) only if we're making a detached signature
 474                 if (state.mDetached) {
 475                         CFRef<CFDataRef> identification = MachORep::identificationFor(arch.source.get());
 476                         arch.add(cdIdentificationSlot, BlobWrapper::alloc(
 477                                 CFDataGetBytePtr(identification), CFDataGetLength(identification)));
 478                 }
 479
 480                 // prepare SuperBlob size estimate
 481                 __block std::vector<size_t> sizes;
 482                 arch.eachDigest(^(CodeDirectory::Builder& builder){
 483                         sizes.push_back(builder.size(CodeDirectory::currentVersion));
 484                 });
 485                 arch.blobSize = arch.size(sizes, state.mCMSSize, 0);
 486         }
 487
 488         editor->allocate();
 489
 490         // pass 2: Finish and generate signatures, and write them
 491         for (MachOEditor::Iterator it = editor->begin(); it != editor->end(); ++it) {
 492                 MachOEditor::Arch &arch = *it->second;
 493                 editor->reset(arch);
 494
 495                 // finish CodeDirectories (off new binary) and sign it
 496                 __block CodeDirectorySet cdSet;
 497                 arch.eachDigest(^(CodeDirectory::Builder &builder) {
 498                         CodeDirectory *cd = builder.build();
 499                         cdSet.add(cd);
 500                 });
 501                 CFRef<CFArrayRef> hashes = cdSet.hashBag();
 502                 CFTemp<CFDictionaryRef> hashDict("{cdhashes=%O}", hashes.get());
 503                 CFRef<CFDataRef> hashBag = makeCFData(hashDict.get());
 504                 CFRef<CFDataRef> signature = signCodeDirectory(cdSet.primary(), hashBag);
 505
 506                 // complete the SuperBlob
 507                 cdSet.populate(&arch);
 508                 arch.add(cdSignatureSlot, BlobWrapper::alloc(
 509                         CFDataGetBytePtr(signature), CFDataGetLength(signature)));
 510                 if (!state.mDryRun) {
 511                         EmbeddedSignatureBlob *blob = arch.make();
 512                         editor->write(arch, blob);      // takes ownership of blob
 513                 }
 514         }
 515
 516         // done: write edit copy back over the original
 517         if (!state.mDryRun) {
 518                 editor->commit();
 519         }
 520 }
 521
 522
 523 //
 524 // Sign a binary that has no notion of architecture.
 525 // That currently means anything that isn't Mach-O format.
 526 //
 527 void SecCodeSigner::Signer::signArchitectureAgnostic(const Requirement::Context &context)
 528 {
 529         // non-Mach-O executable - single-instance signing
 530         RefPointer<DiskRep::Writer> writer = state.mDetached ?
 531                 (new DetachedBlobWriter(*this)) : rep->writer();
 532
 533         CodeDirectorySet cdSet;
 534         for (auto type = digestAlgorithms().begin(); type != digestAlgorithms().end(); ++type) {
 535                 CodeDirectory::Builder builder(*type);
 536                 InternalRequirements ireqs;
 537                 ireqs(requirements, rep->defaultRequirements(NULL, *this), context);
 538                 populate(*writer);
 539                 populate(builder, *writer, ireqs, rep->signingBase(), rep->signingLimit(), unsigned(digestAlgorithms().size()-1));
 540
 541                 CodeDirectory *cd = builder.build();
 542                 if (!state.mDryRun)
 543                         cdSet.add(cd);
 544         }
 545
 546         // add identification blob (made from this architecture) only if we're making a detached signature
 547         if (state.mDetached) {
 548                 CFRef<CFDataRef> identification = rep->identification();
 549                 writer->component(cdIdentificationSlot, identification);
 550         }
 551
 552         // write out all CodeDirectories
 553         if (!state.mDryRun)
 554                 cdSet.populate(writer);
 555
 556         CFRef<CFArrayRef> hashes = cdSet.hashBag();
 557         CFTemp<CFDictionaryRef> hashDict("{cdhashes=%O}", hashes.get());
 558         CFRef<CFDataRef> hashBag = makeCFData(hashDict.get());
 559         CFRef<CFDataRef> signature = signCodeDirectory(cdSet.primary(), hashBag);
 560         writer->signature(signature);
 561
 562         // commit to storage
 563         writer->flush();
 564 }
 565
 566
 567 //
 568 // Global populate - send components to destination buffers ONCE
 569 //
 570 void SecCodeSigner::Signer::populate(DiskRep::Writer &writer)
 571 {
 572         if (resourceDirectory && !state.mDryRun)
 573                 writer.component(cdResourceDirSlot, resourceDictData);
 574 }
 575
 576
 577 //
 578 // Per-architecture populate - send components to per-architecture buffers
 579 // and populate the CodeDirectory for an architecture. In architecture-agnostic
 580 // signing operations, the non-architectural binary is considered one (arbitrary) architecture
 581 // for the purposes of this call.
 582 //
 583 void SecCodeSigner::Signer::populate(CodeDirectory::Builder &builder, DiskRep::Writer &writer,
 584         InternalRequirements &ireqs, size_t offset, size_t length, unsigned alternateDigestCount)
 585 {
 586         // fill the CodeDirectory
 587         builder.executable(rep->mainExecutablePath(), pagesize, offset, length);
 588         builder.flags(cdFlags);
 589         builder.identifier(identifier);
 590         builder.teamID(teamID);
 591         builder.platform(state.mPlatform);
 592
 593         if (CFRef<CFDataRef> data = rep->component(cdInfoSlot))
 594                 builder.specialSlot(cdInfoSlot, data);
 595         if (ireqs) {
 596                 CFRef<CFDataRef> data = makeCFData(*ireqs);
 597                 writer.component(cdRequirementsSlot, data);
 598                 builder.specialSlot(cdRequirementsSlot, data);
 599         }
 600         if (resourceDirectory)
 601                 builder.specialSlot(cdResourceDirSlot, resourceDictData);
 602         if (entitlements) {
 603                 writer.component(cdEntitlementSlot, entitlements);
 604                 builder.specialSlot(cdEntitlementSlot, entitlements);
 605         }
 606         if (CFRef<CFDataRef> repSpecific = rep->component(cdRepSpecificSlot))
 607                 builder.specialSlot(cdRepSpecificSlot, repSpecific);
 608
 609         writer.addDiscretionary(builder);
 610
 611 #if 0 // rdar://problem/25720754
 612         if ((signingFlags() & (kSecCSSignOpaque|kSecCSSignV1)) == 0 && builder.hashType() != kSecCodeSignatureHashSHA1) {
 613                 // calculate sorted list of top SuperBlob keys in this EmbeddedSignatureBlob (if any)
 614                 // (but not for opaque or V1 construction, which must remain bit-for-bit compatible)
 615                 std::vector<Endian<uint32_t> > slotVector;
 616                 slotVector.push_back(cdCodeDirectorySlot);      // mandatory
 617                 std::set<CodeDirectory::Slot> filledSlots = builder.filledSpecialSlots();
 618                 filledSlots.insert(cdTopDirectorySlot);         // will be added below
 619                 copy(filledSlots.begin(), filledSlots.end(), back_inserter(slotVector));
 620                 for (unsigned n = 0; n < alternateDigestCount; n++)
 621                         slotVector.push_back(cdAlternateCodeDirectorySlots + n);
 622                 slotVector.push_back(cdSignatureSlot);
 623                 CFTempData cfSlotVector(&slotVector[0], slotVector.size() * sizeof(slotVector[0]));
 624                 writer.component(cdTopDirectorySlot, cfSlotVector);
 625                 builder.specialSlot(cdTopDirectorySlot, cfSlotVector);
 626         }
 627 #endif
 628 }
 629
 630
 631 #include <security_smime/tsaSupport.h>
 632
 633 //
 634 // Generate the CMS signature for a (finished) CodeDirectory.
 635 //
 636 CFDataRef SecCodeSigner::Signer::signCodeDirectory(const CodeDirectory *cd, CFDataRef hashBag)
 637 {
 638         assert(state.mSigner);
 639         CFRef<CFMutableDictionaryRef> defaultTSContext = NULL;
 640
 641         // a null signer generates a null signature blob
 642         if (state.mSigner == SecIdentityRef(kCFNull))
 643                 return CFDataCreate(NULL, NULL, 0);
 644
 645         // generate CMS signature
 646         CFRef<CMSEncoderRef> cms;
 647         MacOSError::check(CMSEncoderCreate(&cms.aref()));
 648         MacOSError::check(CMSEncoderSetCertificateChainMode(cms, kCMSCertificateChainWithRoot));
 649         CMSEncoderAddSigners(cms, state.mSigner);
 650         CMSEncoderSetSignerAlgorithm(cms, kCMSEncoderDigestAlgorithmSHA256);
 651         MacOSError::check(CMSEncoderSetHasDetachedContent(cms, true));
 652
 653         if (emitSigningTime) {
 654                 MacOSError::check(CMSEncoderAddSignedAttributes(cms, kCMSAttrSigningTime));
 655                 CFAbsoluteTime time = signingTime ? signingTime : CFAbsoluteTimeGetCurrent();
 656                 MacOSError::check(CMSEncoderSetSigningTime(cms, time));
 657         }
 658
 659         if (hashBag) {
 660                 MacOSError::check(CMSEncoderAddSignedAttributes(cms, kCMSAttrAppleCodesigningHashAgility));
 661                 MacOSError::check(CMSEncoderSetAppleCodesigningHashAgility(cms, hashBag));
 662         }
 663
 664         MacOSError::check(CMSEncoderUpdateContent(cms, cd, cd->length()));
 665
 666     // Set up to call Timestamp server if requested
 667     if (state.mWantTimeStamp)
 668     {
 669         CFRef<CFErrorRef> error = NULL;
 670         defaultTSContext = SecCmsTSAGetDefaultContext(&error.aref());
 671         if (error)
 672             MacOSError::throwMe(errSecDataNotAvailable);
 673
 674         if (state.mNoTimeStampCerts || state.mTimestampService) {
 675             if (state.mTimestampService)
 676                 CFDictionarySetValue(defaultTSContext, kTSAContextKeyURL, state.mTimestampService);
 677             if (state.mNoTimeStampCerts)
 678                 CFDictionarySetValue(defaultTSContext, kTSAContextKeyNoCerts, kCFBooleanTrue);
 679                 }
 680
 681                 CmsMessageSetTSAContext(cms, defaultTSContext);
 682     }
 683
 684         CFDataRef signature;
 685         MacOSError::check(CMSEncoderCopyEncodedContent(cms, &signature));
 686
 687         return signature;
 688 }
 689
 690
 691 //
 692 // Our DiskRep::signingContext methods communicate with the signing subsystem
 693 // in terms those callers can easily understand.
 694 //
 695 string SecCodeSigner::Signer::sdkPath(const std::string &path) const
 696 {
 697         assert(path[0] == '/'); // need absolute path here
 698         if (state.mSDKRoot)
 699                 return cfString(state.mSDKRoot) + path;
 700         else
 701                 return path;
 702 }
 703
 704 bool SecCodeSigner::Signer::isAdhoc() const
 705 {
 706         return state.mSigner == SecIdentityRef(kCFNull);
 707 }
 708
 709 SecCSFlags SecCodeSigner::Signer::signingFlags() const
 710 {
 711         return state.mOpFlags;
 712 }
 713
 714
 715 //
 716 // Parse a text of the form
 717 //      flag,...,flag
 718 // where each flag is the canonical name of a signable CodeDirectory flag.
 719 // No abbreviations are allowed, and internally set flags are not accepted.
 720 //
 721 uint32_t SecCodeSigner::Signer::cdTextFlags(std::string text)
 722 {
 723         uint32_t flags = 0;
 724         for (string::size_type comma = text.find(','); ; text = text.substr(comma+1), comma = text.find(',')) {
 725                 string word = (comma == string::npos) ? text : text.substr(0, comma);
 726                 const SecCodeDirectoryFlagTable *item;
 727                 for (item = kSecCodeDirectoryFlagTable; item->name; item++)
 728                         if (item->signable && word == item->name) {
 729                                 flags |= item->value;
 730                                 break;
 731                         }
 732                 if (!item->name)        // not found
 733                         MacOSError::throwMe(errSecCSInvalidFlags);
 734                 if (comma == string::npos)      // last word
 735                         break;
 736         }
 737         return flags;
 738 }
 739
 740
 741 //
 742 // Generate a unique string from our underlying DiskRep.
 743 // We could get 90%+ of the uniquing benefit by just generating
 744 // a random string here. Instead, we pick the (hex string encoding of)
 745 // the source rep's unique identifier blob. For universal binaries,
 746 // this is the canonical local architecture, which is a bit arbitrary.
 747 // This provides us with a consistent unique string for all architectures
 748 // of a fat binary, *and* (unlike a random string) is reproducible
 749 // for identical inputs, even upon resigning.
 750 //
 751 std::string SecCodeSigner::Signer::uniqueName() const
 752 {
 753         CFRef<CFDataRef> identification = rep->identification();
 754         const UInt8 *ident = CFDataGetBytePtr(identification);
 755         const CFIndex length = CFDataGetLength(identification);
 756         string result;
 757         for (CFIndex n = 0; n < length; n++) {
 758                 char hex[3];
 759                 snprintf(hex, sizeof(hex), "%02x", ident[n]);
 760                 result += hex;
 761         }
 762         return result;
 763 }
 764
 765
 766 } // end namespace CodeSigning
 767 } // end namespace Security