OSX/libsecurity_codesigning/lib/policyengine.cpp

   1 /*
   2  * Copyright (c) 2011-2016 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
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  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #include "policyengine.h"
  24 #include "xar++.h"
  25 #include "quarantine++.h"
  26 #include "codesigning_dtrace.h"
  27 #include <security_utilities/cfmunge.h>
  28 #include <Security/Security.h>
  29 #include <Security/SecCodePriv.h>
  30 #include <Security/SecRequirementPriv.h>
  31 #include <Security/SecPolicyPriv.h>
  32 #include <Security/SecTrustPriv.h>
  33 #include <Security/SecCodeSigner.h>
  34 #include <Security/cssmapplePriv.h>
  35 #include <security_utilities/unix++.h>
  36 #include <notify.h>
  37
  38 #include "diskrep.h"
  39 #include "codedirectory.h"
  40 #include "csutilities.h"
  41 #include "notarization.h"
  42 #include "StaticCode.h"
  43
  44 #include <CoreServices/CoreServicesPriv.h>
  45 #include "SecCodePriv.h"
  46 #undef check // Macro! Yech.
  47
  48 namespace Security {
  49 namespace CodeSigning {
  50
  51 static const double NEGATIVE_HOLD = 60.0/86400; // 60 seconds to cache negative outcomes
  52
  53 static const char RECORDER_DIR[] = "/tmp/gke-";         // recorder mode destination for detached signatures
  54 enum {
  55         recorder_code_untrusted = 0,            // signed but untrusted
  56         recorder_code_adhoc = 1,                        // unsigned; signature recorded
  57         recorder_code_unable = 2,                       // unsigned; unable to record signature
  58 };
  59
  60
  61 static void authorizeUpdate(SecAssessmentFlags flags, CFDictionaryRef context);
  62 static CFTypeRef installerPolicy() CF_RETURNS_RETAINED;
  63
  64
  65 //
  66 // Core structure
  67 //
  68 PolicyEngine::PolicyEngine()
  69         : PolicyDatabase(NULL, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE)
  70 {
  71         try {
  72                 mOpaqueWhitelist = new OpaqueWhitelist();
  73         } catch (...) {
  74                 mOpaqueWhitelist = NULL;
  75                 secerror("Failed opening the gkopaque database.");
  76         }
  77 }
  78
  79 PolicyEngine::~PolicyEngine()
  80 {
  81         delete mOpaqueWhitelist;
  82 }
  83
  84
  85 //
  86 // Top-level evaluation driver
  87 //
  88 void PolicyEngine::evaluate(CFURLRef path, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context, CFMutableDictionaryRef result)
  89 {
  90     // update GKE
  91     installExplicitSet(gkeAuthFile, gkeSigsFile);
  92
  93     // find the global evaluation manager
  94     EvaluationManager *evaluationManager = EvaluationManager::globalManager();
  95
  96     // perform the evaluation
  97     EvaluationTask *evaluationTask = evaluationManager->evaluationTask(this, path, type, flags, context, result);
  98     evaluationManager->finalizeTask(evaluationTask, flags, result);
  99
 100     // if rejected, reset the automatic rearm timer
 101     if (CFDictionaryGetValue(result, kSecAssessmentAssessmentVerdict) == kCFBooleanFalse)
 102         resetRearmTimer("reject");
 103 }
 104
 105
 106 //
 107 // Create GKE whitelist filter screens.
 108 // These are strings that are used to determine quickly whether unsigned code may
 109 // have a GKE-style whitelist entry in the authority database. The idea is to make
 110 // up a decent hash quickly.
 111 //
 112 // Note: We continue to use SHA1 here for compatibility of existing GKE entries.
 113 // These are a prescreen, backed up by code signature checks later on. Use of SHA1 here is not a security problem.
 114 //
 115 static std::string createWhitelistScreen(char type, const Byte *digest, size_t length)
 116 {
 117         char buffer[2*length + 2];
 118         buffer[0] = type;
 119         for (size_t n = 0; n < length; n++)
 120                 sprintf(buffer + 1 + 2*n, "%02.2x", digest[n]);
 121         return buffer;
 122 }
 123
 124 static std::string createWhitelistScreen(SecStaticCodeRef code)
 125 {
 126         DiskRep *rep = SecStaticCode::requiredStatic(code)->diskRep();
 127         std::string screen;
 128         if (CFRef<CFDataRef> info = rep->component(cdInfoSlot)) {
 129                 // has an Info.plist - hash it
 130                 SHA1 hash;
 131                 hash.update(CFDataGetBytePtr(info), CFDataGetLength(info));
 132                 SHA1::Digest digest;
 133                 hash.finish(digest);
 134                 return createWhitelistScreen('I', digest, sizeof(digest));
 135         } else if (CFRef<CFDataRef> repSpecific = rep->component(cdRepSpecificSlot)) {
 136                 // has a rep-specific slot - hash that (this catches disk images cheaply)
 137                 // got invented after SHA-1 deprecation, so we'll use SHA256, which is the new default
 138                 CCHashInstance hash(kCCDigestSHA256);
 139                 hash.update(CFDataGetBytePtr(repSpecific), CFDataGetLength(repSpecific));
 140                 Byte digest[256/8];
 141                 hash.finish(digest);
 142                 return createWhitelistScreen('R', digest, sizeof(digest));
 143         } else if (rep->mainExecutableImage()) {
 144                 // stand-alone Mach-O executables are always candidates
 145                 return "N";
 146         } else {
 147                 // if everything else fails, hash the (single) file
 148                 SHA1 hash;
 149                 hashFileData(rep->mainExecutablePath().c_str(), &hash);
 150                 SHA1::Digest digest;
 151                 hash.finish(digest);
 152                 return createWhitelistScreen('M', digest, sizeof(digest));
 153         }
 154 }
 155
 156
 157 void PolicyEngine::evaluateCodeItem(SecStaticCodeRef code, CFURLRef path, AuthorityType type, SecAssessmentFlags flags, bool nested, CFMutableDictionaryRef result)
 158 {
 159
 160         SQLite::Statement query(*this,
 161                 "SELECT allow, requirement, id, label, expires, flags, disabled, filter_unsigned, remarks FROM scan_authority"
 162                 " WHERE type = :type"
 163                 " ORDER BY priority DESC;");
 164         query.bind(":type").integer(type);
 165
 166         SQLite3::int64 latentID = 0;            // first (highest priority) disabled matching ID
 167         std::string latentLabel;                        // ... and associated label, if any
 168
 169     secdebug("gk", "evaluateCodeItem type=%d flags=0x%x nested=%d path=%s", type, int(flags), nested, cfString(path).c_str());
 170         while (query.nextRow()) {
 171                 bool allow = int(query[0]);
 172                 const char *reqString = query[1];
 173                 SQLite3::int64 id = query[2];
 174                 const char *label = query[3];
 175                 double expires = query[4];
 176                 sqlite3_int64 ruleFlags = query[5];
 177                 SQLite3::int64 disabled = query[6];
 178 //              const char *filter = query[7];
 179 //              const char *remarks = query[8];
 180
 181                 secdebug("gk", "considering rule %d(%s) requirement %s", int(id), label ? label : "UNLABELED", reqString);
 182                 CFRef<SecRequirementRef> requirement;
 183                 MacOSError::check(SecRequirementCreateWithString(CFTempString(reqString), kSecCSDefaultFlags, &requirement.aref()));
 184                 switch (OSStatus rc = SecStaticCodeCheckValidity(code, kSecCSBasicValidateOnly | kSecCSCheckGatekeeperArchitectures, requirement)) {
 185                 case errSecSuccess:
 186                         break;                                          // rule match; process below
 187                 case errSecCSReqFailed:
 188                         continue;                                       // rule does not apply
 189                 case errSecCSVetoed:
 190                         return;                                         // nested code has failed to pass
 191                 default:
 192                         MacOSError::throwMe(rc);        // general error; pass to caller
 193                 }
 194
 195                 // If this rule is disabled, do not continue any further and just continue iterating
 196                 // until we find one that is enabled.
 197                 if (disabled) {
 198                         // ...but always record the first matching rule for informational purposes.
 199                         if (latentID == 0) {
 200                                 latentID = id;
 201                                 latentLabel = label ? label : "";
 202                         }
 203                         continue;
 204                 }
 205
 206                 // current rule is first rule (in priority order) that matched. Apply it
 207         secnotice("gk", "rule %d applies - allow=%d", int(id), allow);
 208                 if (nested && allow)                    // success, nothing to record
 209                         return;
 210
 211                 CFRef<CFDictionaryRef> info;    // as needed
 212                 if (flags & kSecAssessmentFlagRequestOrigin) {
 213                         if (!info)
 214                                 MacOSError::check(SecCodeCopySigningInformation(code, kSecCSSigningInformation, &info.aref()));
 215                         if (CFArrayRef chain = CFArrayRef(CFDictionaryGetValue(info, kSecCodeInfoCertificates)))
 216                                 setOrigin(chain, result);
 217                 }
 218                 if (!(ruleFlags & kAuthorityFlagInhibitCache) && !(flags & kSecAssessmentFlagNoCache)) {        // cache inhibit
 219                         if (!info)
 220                                 MacOSError::check(SecCodeCopySigningInformation(code, kSecCSSigningInformation, &info.aref()));
 221                         if (SecTrustRef trust = SecTrustRef(CFDictionaryGetValue(info, kSecCodeInfoTrust))) {
 222                                 CFRef<CFDictionaryRef> xinfo;
 223                                 MacOSError::check(SecTrustCopyExtendedResult(trust, &xinfo.aref()));
 224                                 if (CFDateRef limit = CFDateRef(CFDictionaryGetValue(xinfo, kSecTrustExpirationDate))) {
 225                                         this->recordOutcome(code, allow, type, min(expires, dateToJulian(limit)), id);
 226                                 }
 227                         }
 228                 }
 229                 if (allow) {
 230                         if (SYSPOLICY_ASSESS_OUTCOME_ACCEPT_ENABLED()) {
 231                                 if (!info)
 232                                         MacOSError::check(SecCodeCopySigningInformation(code, kSecCSSigningInformation, &info.aref()));
 233                                 CFDataRef cdhash = CFDataRef(CFDictionaryGetValue(info, kSecCodeInfoUnique));
 234                                 SYSPOLICY_ASSESS_OUTCOME_ACCEPT(cfString(path).c_str(), type, label, cdhash ? CFDataGetBytePtr(cdhash) : NULL);
 235                         }
 236                 } else {
 237                         if (SYSPOLICY_ASSESS_OUTCOME_DENY_ENABLED() || SYSPOLICY_RECORDER_MODE_ENABLED()) {
 238                                 if (!info)
 239                                         MacOSError::check(SecCodeCopySigningInformation(code, kSecCSSigningInformation, &info.aref()));
 240                                 CFDataRef cdhash = CFDataRef(CFDictionaryGetValue(info, kSecCodeInfoUnique));
 241                                 std::string cpath = cfString(path);
 242                                 const void *hashp = cdhash ? CFDataGetBytePtr(cdhash) : NULL;
 243                                 SYSPOLICY_ASSESS_OUTCOME_DENY(cpath.c_str(), type, label, hashp);
 244                                 SYSPOLICY_RECORDER_MODE(cpath.c_str(), type, label, hashp, recorder_code_untrusted);
 245                         }
 246                 }
 247                 cfadd(result, "{%O=%B}", kSecAssessmentAssessmentVerdict, allow);
 248                 addAuthority(flags, result, label, id, NULL, false, ruleFlags);
 249                 return;
 250         }
 251
 252         // no applicable authority (but signed, perhaps temporarily). Deny by default
 253     secnotice("gk", "rejecting due to lack of matching active rule");
 254         CFRef<CFDictionaryRef> info;
 255         MacOSError::check(SecCodeCopySigningInformation(code, kSecCSSigningInformation, &info.aref()));
 256         if (flags & kSecAssessmentFlagRequestOrigin) {
 257                 if (CFArrayRef chain = CFArrayRef(CFDictionaryGetValue(info, kSecCodeInfoCertificates)))
 258                         setOrigin(chain, result);
 259         }
 260         if (SYSPOLICY_ASSESS_OUTCOME_DEFAULT_ENABLED() || SYSPOLICY_RECORDER_MODE_ENABLED()) {
 261                 CFDataRef cdhash = CFDataRef(CFDictionaryGetValue(info, kSecCodeInfoUnique));
 262                 const void *hashp = cdhash ? CFDataGetBytePtr(cdhash) : NULL;
 263                 std::string cpath = cfString(path);
 264                 SYSPOLICY_ASSESS_OUTCOME_DEFAULT(cpath.c_str(), type, latentLabel.c_str(), hashp);
 265                 SYSPOLICY_RECORDER_MODE(cpath.c_str(), type, latentLabel.c_str(), hashp, 0);
 266         }
 267         if (!(flags & kSecAssessmentFlagNoCache))
 268                 this->recordOutcome(code, false, type, this->julianNow() + NEGATIVE_HOLD, latentID);
 269         cfadd(result, "{%O=%B}", kSecAssessmentAssessmentVerdict, false);
 270         addAuthority(flags, result, latentLabel.c_str(), latentID);
 271 }
 272
 273 CFDictionaryRef PolicyEngine::opaqueWhitelistValidationConditionsFor(SecStaticCodeRef code)
 274 {
 275          return (mOpaqueWhitelist != NULL) ? mOpaqueWhitelist->validationConditionsFor(code) : NULL;
 276 }
 277
 278 bool PolicyEngine::opaqueWhiteListContains(SecStaticCodeRef code, SecAssessmentFeedback feedback, OSStatus reason)
 279 {
 280         return (mOpaqueWhitelist != NULL) ? mOpaqueWhitelist->contains(code, feedback, reason) : false;
 281 }
 282
 283 void PolicyEngine::opaqueWhitelistAdd(SecStaticCodeRef code)
 284 {
 285         if (mOpaqueWhitelist) {
 286                 mOpaqueWhitelist->add(code);
 287         }
 288 }
 289
 290 void PolicyEngine::adjustValidation(SecStaticCodeRef code)
 291 {
 292         CFRef<CFDictionaryRef> conditions = opaqueWhitelistValidationConditionsFor(code);
 293         SecStaticCodeSetValidationConditions(code, conditions);
 294 }
 295
 296
 297 bool PolicyEngine::temporarySigning(SecStaticCodeRef code, AuthorityType type, CFURLRef path, SecAssessmentFlags matchFlags)
 298 {
 299     secnotice("gk", "temporarySigning type=%d matchFlags=0x%x path=%s", type, int(matchFlags), cfString(path).c_str());
 300
 301     // see if we have a screened record to take matchFlags from
 302     std::string screen = createWhitelistScreen(code);
 303     SQLite::Statement query(*this,
 304         "SELECT flags FROM authority "
 305         "WHERE type = :type"
 306         " AND NOT flags & :flag"
 307         " AND CASE WHEN filter_unsigned IS NULL THEN remarks = :remarks ELSE filter_unsigned = :screen END");
 308     query.bind(":type").integer(type);
 309     query.bind(":flag").integer(kAuthorityFlagDefault);
 310     query.bind(":screen") = screen;
 311     query.bind(":remarks") = cfString(path);
 312     secdebug("gk", "match screen=%s", screen.c_str());
 313     if (query.nextRow())        // got a matching rule
 314         matchFlags = SQLite3::int64(query[0]);
 315     else if (matchFlags == 0)  // lazy and no match
 316         return false;
 317     secdebug("gk", "matchFlags found=0x%x", int(matchFlags));
 318
 319         try {
 320                 // ad-hoc sign the code and attach the signature
 321                 CFRef<CFDataRef> signature = CFDataCreateMutable(NULL, 0);
 322                 CFTemp<CFMutableDictionaryRef> arguments("{%O=%O, %O=#N, %O=%d}", kSecCodeSignerDetached, signature.get(), kSecCodeSignerIdentity,
 323                         kSecCodeSignerDigestAlgorithm, (matchFlags & kAuthorityFlagWhitelistSHA256) ? kSecCodeSignatureHashSHA256 : kSecCodeSignatureHashSHA1);
 324                 // for modern whitelist entries, neuter the identifier since it may be derived from the filename
 325                 if (matchFlags & kAuthorityFlagWhitelistSHA256)
 326                         CFDictionaryAddValue(arguments, kSecCodeSignerIdentifier, CFSTR("ADHOC"));
 327                 CFRef<SecCodeSignerRef> signer;
 328                 MacOSError::check(SecCodeSignerCreate(arguments, (matchFlags & kAuthorityFlagWhitelistV2) ? kSecCSSignOpaque : kSecCSSignV1, &signer.aref()));
 329                 MacOSError::check(SecCodeSignerAddSignature(signer, code, kSecCSDefaultFlags));
 330                 MacOSError::check(SecCodeSetDetachedSignature(code, signature, kSecCSDefaultFlags));
 331
 332                 SecRequirementRef dr = NULL;
 333                 SecCodeCopyDesignatedRequirement(code, kSecCSDefaultFlags, &dr);
 334                 CFStringRef drs = NULL;
 335                 SecRequirementCopyString(dr, kSecCSDefaultFlags, &drs);
 336         secnotice("gk", "successfully created temporary signature - requirement=%s", cfString(drs).c_str());
 337
 338                 // if we're in GKE recording mode, save that signature and report its location
 339                 if (SYSPOLICY_RECORDER_MODE_ENABLED()) {
 340                         int status = recorder_code_unable;      // ephemeral signature (not recorded)
 341                         if (geteuid() == 0) {
 342                                 CFRef<CFUUIDRef> uuid = CFUUIDCreate(NULL);
 343                                 std::string sigfile = RECORDER_DIR + cfStringRelease(CFUUIDCreateString(NULL, uuid)) + ".tsig";
 344                                 try {
 345                                         UnixPlusPlus::AutoFileDesc fd(sigfile, O_WRONLY | O_CREAT);
 346                                         fd.write(CFDataGetBytePtr(signature), CFDataGetLength(signature));
 347                                         status = recorder_code_adhoc;   // recorded signature
 348                                         SYSPOLICY_RECORDER_MODE_ADHOC_PATH(cfString(path).c_str(), type, sigfile.c_str());
 349                                 } catch (...) { }
 350                         }
 351
 352                         // now report the D probe itself
 353                         CFRef<CFDictionaryRef> info;
 354                         MacOSError::check(SecCodeCopySigningInformation(code, kSecCSDefaultFlags, &info.aref()));
 355                         CFDataRef cdhash = CFDataRef(CFDictionaryGetValue(info, kSecCodeInfoUnique));
 356                         SYSPOLICY_RECORDER_MODE(cfString(path).c_str(), type, "",
 357                                 cdhash ? CFDataGetBytePtr(cdhash) : NULL, status);
 358                 }
 359
 360                 return true;    // it worked; we're now (well) signed
 361         } catch (...) { }
 362
 363         return false;
 364 }
 365
 366
 367 //
 368 // Executable code.
 369 // Read from disk, evaluate properly, cache as indicated.
 370 //
 371 void PolicyEngine::evaluateCode(CFURLRef path, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context, CFMutableDictionaryRef result, bool handleUnsigned)
 372 {
 373         // not really a Gatekeeper function... but reject all "hard quarantined" files because they were made from sandboxed sources without download privilege
 374     if (type == kAuthorityExecute) {
 375         FileQuarantine qtn(cfString(path).c_str());
 376         if (qtn.flag(QTN_FLAG_HARD))
 377             MacOSError::throwMe(errSecCSFileHardQuarantined);
 378     }
 379
 380         // hack: if caller passed a UTI, use that to turn off app-only checks for some well-known ones
 381         bool appOk = false;
 382         if (CFStringRef uti = CFStringRef(CFDictionaryGetValue(context, kSecAssessmentContextKeyUTI))) {
 383                 appOk = CFEqual(uti, CFSTR("com.apple.systempreference.prefpane"))
 384                         || CFEqual(uti, CFSTR("com.apple.systempreference.screen-saver"))
 385                         || CFEqual(uti, CFSTR("com.apple.systempreference.screen-slide-saver"))
 386                         || CFEqual(uti, CFSTR("com.apple.menu-extra"));
 387         }
 388
 389         CFCopyRef<SecStaticCodeRef> code;
 390         MacOSError::check(SecStaticCodeCreateWithPath(path, kSecCSDefaultFlags | kSecCSForceOnlineNotarizationCheck, &code.aref()));
 391
 392         SecCSFlags validationFlags = kSecCSEnforceRevocationChecks | kSecCSCheckAllArchitectures;
 393         if (!(flags & kSecAssessmentFlagAllowWeak))
 394                 validationFlags |= kSecCSStrictValidate;
 395         adjustValidation(code);
 396
 397         // deal with a very special case (broken 10.6/10.7 Applet bundles)
 398         OSStatus rc = SecStaticCodeCheckValidity(code, validationFlags | kSecCSBasicValidateOnly, NULL);
 399         if (rc == errSecCSSignatureFailed) {
 400                 MacOSError::throwMe(rc);
 401         }
 402
 403         // ad-hoc sign unsigned code
 404     bool wasAdhocSigned = false;
 405         if (rc == errSecCSUnsigned && handleUnsigned && (!overrideAssessment(flags) || SYSPOLICY_RECORDER_MODE_ENABLED())) {
 406                 if (temporarySigning(code, type, path, 0)) {
 407             wasAdhocSigned = true;
 408                         rc = errSecSuccess;             // clear unsigned; we are now well-signed
 409                         validationFlags |= kSecCSBasicValidateOnly;     // no need to re-validate deep contents
 410                 }
 411         }
 412
 413         // prepare for deep traversal of (hopefully) good signatures
 414         SecAssessmentFeedback feedback = SecAssessmentFeedback(CFDictionaryGetValue(context, kSecAssessmentContextKeyFeedback));
 415         __block CFRef<CFMutableDictionaryRef> nestedFailure = NULL;     // save a nested failure for later
 416         MacOSError::check(SecStaticCodeSetCallback(code, kSecCSDefaultFlags, NULL, ^CFTypeRef (SecStaticCodeRef item, CFStringRef cfStage, CFDictionaryRef info) {
 417                 string stage = cfString(cfStage);
 418                 if (stage == "prepared") {
 419                         if (!CFEqual(item, code))       // genuine nested (not top) code
 420                                 adjustValidation(item);
 421                 } else if (stage == "progress") {
 422                         if (feedback && CFEqual(item, code)) {  // top level progress
 423                                 bool proceed = feedback(kSecAssessmentFeedbackProgress, info);
 424                                 if (!proceed)
 425                                         SecStaticCodeCancelValidation(code, kSecCSDefaultFlags);
 426                         }
 427                 } else if (stage == "validated") {
 428                         SecStaticCodeSetCallback(item, kSecCSDefaultFlags, NULL, NULL);         // clear callback to avoid unwanted recursion
 429                         evaluateCodeItem(item, path, type, flags, item != code, result);
 430                         if (CFTypeRef verdict = CFDictionaryGetValue(result, kSecAssessmentAssessmentVerdict))
 431                                 if (CFEqual(verdict, kCFBooleanFalse)) {
 432                                         if (item == code)
 433                                                 return makeCFNumber(OSStatus(errSecCSVetoed));  // (signal nested-code policy failure, picked up below)
 434                                         // nested code policy failure; save, reset, and continue
 435                                         if (!nestedFailure)
 436                                                 nestedFailure = CFMutableDictionaryRef(CFDictionaryGetValue(result, kSecAssessmentAssessmentAuthority));
 437                                         CFDictionaryRemoveValue(result, kSecAssessmentAssessmentAuthority);
 438                                         CFDictionaryRemoveValue(result, kSecAssessmentAssessmentVerdict);
 439                                 }
 440                 }
 441                 return NULL;
 442         }));
 443
 444         // go for it!
 445         SecCSFlags topFlags = validationFlags | kSecCSCheckNestedCode | kSecCSRestrictSymlinks | kSecCSReportProgress;
 446         if (type == kAuthorityExecute && !appOk)
 447                 topFlags |= kSecCSRestrictToAppLike;
 448         switch (rc = SecStaticCodeCheckValidity(code, topFlags, NULL)) {
 449         case errSecSuccess:             // continue below
 450                 break;
 451         case errSecCSUnsigned:
 452                 cfadd(result, "{%O=#F}", kSecAssessmentAssessmentVerdict);
 453                 addAuthority(flags, result, "no usable signature");
 454                 return;
 455         case errSecCSVetoed:            // nested code rejected by rule book; result was filled out there
 456         if (wasAdhocSigned)
 457             addToAuthority(result, kSecAssessmentAssessmentSource, CFSTR("no usable signature"));   // ad-hoc signature proved useless
 458                 return;
 459         case errSecCSWeakResourceRules:
 460         case errSecCSWeakResourceEnvelope:
 461         case errSecCSResourceNotSupported:
 462         case errSecCSAmbiguousBundleFormat:
 463         case errSecCSSignatureNotVerifiable:
 464         case errSecCSRegularFile:
 465         case errSecCSBadMainExecutable:
 466         case errSecCSBadFrameworkVersion:
 467         case errSecCSUnsealedAppRoot:
 468         case errSecCSUnsealedFrameworkRoot:
 469         case errSecCSInvalidSymlink:
 470         case errSecCSNotAppLike:
 471         {
 472                 // consult the whitelist
 473                 bool allow = false;
 474                 const char *label;
 475                 // we've bypassed evaluateCodeItem before we failed validation. Explicitly apply it now
 476                 SecStaticCodeSetCallback(code, kSecCSDefaultFlags, NULL, NULL);
 477                 evaluateCodeItem(code, path, type, flags | kSecAssessmentFlagNoCache, false, result);
 478                 if (CFTypeRef verdict = CFDictionaryGetValue(result, kSecAssessmentAssessmentVerdict)) {
 479                         // verdict rendered from a nested component - signature not acceptable to Gatekeeper
 480                         if (CFEqual(verdict, kCFBooleanFalse))  // nested code rejected by rule book; result was filled out there
 481                                 return;
 482                         if (CFEqual(verdict, kCFBooleanTrue) && !(flags & kSecAssessmentFlagIgnoreWhitelist))
 483                                 if (opaqueWhiteListContains(code, feedback, rc)) {
 484                                         allow = true;
 485                                 }
 486                 }
 487                 if (allow) {
 488                         label = "allowed cdhash";
 489                 } else {
 490                         CFDictionaryReplaceValue(result, kSecAssessmentAssessmentVerdict, kCFBooleanFalse);
 491                         label = "obsolete resource envelope";
 492                 }
 493                 cfadd(result, "{%O=%d}", kSecAssessmentAssessmentCodeSigningError, rc);
 494                 addAuthority(flags, result, label, 0, NULL, true);
 495                 return;
 496         }
 497         default:
 498                 MacOSError::throwMe(rc);
 499         }
 500
 501         // Copy notarization date, if present, from code signing information
 502         CFRef<CFDictionaryRef> info;
 503         OSStatus status = SecCodeCopySigningInformation(code, kSecCSInternalInformation, &info.aref());
 504         if (status == 0 && info) {
 505                 CFDateRef date = (CFDateRef)CFDictionaryGetValue(info, kSecCodeInfoNotarizationDate);
 506                 if (date) {
 507                         cfadd(result, "{%O=%O}", kSecAssessmentAssessmentNotarizationDate, date);
 508                 }
 509         } else {
 510                 secerror("Unable to copy signing information: %d", (int)status);
 511         }
 512
 513         if (nestedFailure && CFEqual(CFDictionaryGetValue(result, kSecAssessmentAssessmentVerdict), kCFBooleanTrue)) {
 514                 // structure intact, top level approved, nested code failed policy
 515                 CFMutableDictionaryRef authority = CFMutableDictionaryRef(CFDictionaryGetValue(result, kSecAssessmentAssessmentAuthority));
 516                 uint64_t ruleFlags = cfNumber<uint64_t>(CFNumberRef(CFDictionaryGetValue(authority, kSecAssessmentAssessmentAuthorityFlags)));
 517                 if (ruleFlags & kAuthorityFlagDefault) {
 518                         // default rule requires positive match at each nested code - reinstate failure
 519                         CFDictionaryReplaceValue(result, kSecAssessmentAssessmentVerdict, kCFBooleanFalse);
 520                         CFDictionaryReplaceValue(result, kSecAssessmentAssessmentAuthority, nestedFailure);
 521                 }
 522         }
 523 }
 524
 525
 526 //
 527 // Installer archive.
 528 // Hybrid policy: If we detect an installer signature, use and validate that.
 529 // If we don't, check for a code signature instead.
 530 //
 531 void PolicyEngine::evaluateInstall(CFURLRef path, SecAssessmentFlags flags, CFDictionaryRef context, CFMutableDictionaryRef result)
 532 {
 533         const AuthorityType type = kAuthorityInstall;
 534
 535         // check for recent explicit approval, using a bookmark's FileResourceIdentifierKey
 536         if (CFRef<CFDataRef> bookmark = cfLoadFile(lastApprovedFile)) {
 537                 Boolean stale;
 538                 if (CFRef<CFURLRef> url = CFURLCreateByResolvingBookmarkData(NULL, bookmark,
 539                         kCFBookmarkResolutionWithoutUIMask | kCFBookmarkResolutionWithoutMountingMask, NULL, NULL, &stale, NULL))
 540                         if (CFRef<CFDataRef> savedIdent = CFDataRef(CFURLCreateResourcePropertyForKeyFromBookmarkData(NULL, kCFURLFileResourceIdentifierKey, bookmark)))
 541                                 if (CFRef<CFDateRef> savedMod = CFDateRef(CFURLCreateResourcePropertyForKeyFromBookmarkData(NULL, kCFURLContentModificationDateKey, bookmark))) {
 542                                         CFRef<CFDataRef> currentIdent;
 543                                         CFRef<CFDateRef> currentMod;
 544                                         if (CFURLCopyResourcePropertyForKey(path, kCFURLFileResourceIdentifierKey, &currentIdent.aref(), NULL))
 545                                                 if (CFURLCopyResourcePropertyForKey(path, kCFURLContentModificationDateKey, &currentMod.aref(), NULL))
 546                                                         if (CFEqual(savedIdent, currentIdent) && CFEqual(savedMod, currentMod)) {
 547                                                                 cfadd(result, "{%O=#T}", kSecAssessmentAssessmentVerdict);
 548                                                                 addAuthority(flags, result, "explicit preference");
 549                                                                 return;
 550                                                         }
 551                                 }
 552         }
 553
 554         Xar xar(cfString(path).c_str());
 555         if (!xar) {
 556                 // follow the code signing path
 557                 evaluateCode(path, type, flags, context, result, true);
 558                 return;
 559         }
 560
 561         SQLite3::int64 latentID = 0;            // first (highest priority) disabled matching ID
 562         std::string latentLabel;                        // ... and associated label, if any
 563         if (!xar.isSigned()) {
 564                 // unsigned xar
 565                 if (SYSPOLICY_ASSESS_OUTCOME_UNSIGNED_ENABLED())
 566                         SYSPOLICY_ASSESS_OUTCOME_UNSIGNED(cfString(path).c_str(), type);
 567                 cfadd(result, "{%O=#F}", kSecAssessmentAssessmentVerdict);
 568                 addAuthority(flags, result, "no usable signature");
 569                 return;
 570         }
 571         if (CFRef<CFArrayRef> certs = xar.copyCertChain()) {
 572                 CFRef<CFTypeRef> policy = installerPolicy();
 573                 CFRef<SecTrustRef> trust;
 574                 CFRef<CFDataRef> checksum;
 575                 CFRef<CFStringRef> teamID;
 576                 CFRef<CFMutableDictionaryRef> requirementContext = makeCFMutableDictionary();
 577                 MacOSError::check(SecTrustCreateWithCertificates(certs, policy, &trust.aref()));
 578 //              MacOSError::check(SecTrustSetAnchorCertificates(trust, cfEmptyArray())); // no anchors
 579                 MacOSError::check(SecTrustSetOptions(trust, kSecTrustOptionAllowExpired | kSecTrustOptionImplicitAnchors));
 580
 581                 SecTrustResultType trustResult;
 582                 MacOSError::check(SecTrustEvaluate(trust, &trustResult));
 583                 CFRef<CFArrayRef> chain;
 584                 CSSM_TP_APPLE_EVIDENCE_INFO *info;
 585                 MacOSError::check(SecTrustGetResult(trust, &trustResult, &chain.aref(), &info));
 586
 587                 if (flags & kSecAssessmentFlagRequestOrigin)
 588                         setOrigin(chain, result);
 589
 590                 switch (trustResult) {
 591                 case kSecTrustResultProceed:
 592                 case kSecTrustResultUnspecified:
 593                         break;
 594                 default:
 595                         {
 596                                 OSStatus rc;
 597                                 MacOSError::check(SecTrustGetCssmResultCode(trust, &rc));
 598                                 MacOSError::throwMe(rc);
 599                         }
 600                 }
 601
 602                 xar.registerStapledNotarization();
 603                 checksum.take(xar.createPackageChecksum());
 604                 if (checksum) {
 605                         double notarizationDate = NAN;
 606
 607                         // Force a single online check for the checksum, which is always SHA1.
 608                         bool is_revoked = checkNotarizationServiceForRevocation(checksum, kSecCodeSignatureHashSHA1, &notarizationDate);
 609                         if (is_revoked) {
 610                                 MacOSError::throwMe(errSecCSRevokedNotarization);
 611                         }
 612
 613                         // Extract a team identifier from the certificates.  This isn't validated and could be spoofed,
 614                         // but since the 'legacy' keyword is only used in addition to the Developer ID requirement,
 615                         // this is still stafe for now.
 616                         SecCertificateRef leaf = SecCertificateRef(CFArrayGetValueAtIndex(certs, 0));
 617                         CFRef<CFArrayRef> orgUnits = SecCertificateCopyOrganizationalUnit(leaf);
 618                         if (orgUnits.get() && CFArrayGetCount(orgUnits) == 1) {
 619                                 teamID = (CFStringRef)CFArrayGetValueAtIndex(orgUnits, 0);
 620                         }
 621
 622                         // Create the appropriate requirement context entry to allow notarized requirement check.
 623                         CFRef<CFNumberRef> algorithm = makeCFNumber((uint32_t)xar.checksumDigestAlgorithm());
 624                         cfadd(requirementContext, "{%O=%O}", kSecRequirementKeyPackageChecksum, checksum.get());
 625                         cfadd(requirementContext, "{%O=%O}", kSecRequirementKeyChecksumAlgorithm, algorithm.get());
 626                         if (teamID.get()) {
 627                                 cfadd(requirementContext, "{%O=%O}", kSecRequirementKeyTeamIdentifier, teamID.get());
 628                         }
 629
 630                         if (!isnan(notarizationDate)) {
 631                                 CFRef<CFDateRef> date = CFDateCreate(NULL, notarizationDate);
 632                                 if (date) {
 633                                         cfadd(result, "{%O=%O}", kSecAssessmentAssessmentNotarizationDate, date.get());
 634                                 }
 635                         }
 636                 }
 637
 638                 SQLite::Statement query(*this,
 639                         "SELECT allow, requirement, id, label, flags, disabled FROM scan_authority"
 640                         " WHERE type = :type"
 641                         " ORDER BY priority DESC;");
 642                 query.bind(":type").integer(type);
 643                 while (query.nextRow()) {
 644                         bool allow = int(query[0]);
 645                         const char *reqString = query[1];
 646                         SQLite3::int64 id = query[2];
 647                         const char *label = query[3];
 648                         //sqlite_uint64 ruleFlags = query[4];
 649                         SQLite3::int64 disabled = query[5];
 650
 651                         CFRef<SecRequirementRef> requirement;
 652                         MacOSError::check(SecRequirementCreateWithString(CFTempString(reqString), kSecCSDefaultFlags, &requirement.aref()));
 653                         switch (OSStatus rc = SecRequirementEvaluate(requirement, chain, requirementContext.get(), kSecCSDefaultFlags)) {
 654                         case errSecSuccess: // success
 655                                 break;
 656                         case errSecCSReqFailed: // requirement missed, but otherwise okay
 657                                 continue;
 658                         default: // broken in some way; all tests will fail like this so bail out
 659                                 MacOSError::throwMe(rc);
 660                         }
 661                         if (disabled) {
 662                                 if (latentID == 0) {
 663                                         latentID = id;
 664                                         if (label)
 665                                                 latentLabel = label;
 666                                 }
 667                                 continue;       // the loop
 668                         }
 669
 670                         if (SYSPOLICY_ASSESS_OUTCOME_ACCEPT_ENABLED() || SYSPOLICY_ASSESS_OUTCOME_DENY_ENABLED()) {
 671                                 if (allow)
 672                                         SYSPOLICY_ASSESS_OUTCOME_ACCEPT(cfString(path).c_str(), type, label, NULL);
 673                                 else
 674                                         SYSPOLICY_ASSESS_OUTCOME_DENY(cfString(path).c_str(), type, label, NULL);
 675                         }
 676
 677                         // not adding to the object cache - we could, but it's not likely to be worth it
 678                         cfadd(result, "{%O=%B}", kSecAssessmentAssessmentVerdict, allow);
 679                         addAuthority(flags, result, label, id);
 680                         return;
 681                 }
 682         }
 683         if (SYSPOLICY_ASSESS_OUTCOME_DEFAULT_ENABLED())
 684                 SYSPOLICY_ASSESS_OUTCOME_DEFAULT(cfString(path).c_str(), type, latentLabel.c_str(), NULL);
 685
 686         // no applicable authority. Deny by default
 687         cfadd(result, "{%O=#F}", kSecAssessmentAssessmentVerdict);
 688         addAuthority(flags, result, latentLabel.c_str(), latentID);
 689 }
 690
 691
 692 //
 693 // Create a suitable policy array for verification of installer signatures.
 694 //
 695 static SecPolicyRef makeRevocationPolicy()
 696 {
 697         CFRef<SecPolicyRef> policy(SecPolicyCreateRevocation(kSecRevocationUseAnyAvailableMethod));
 698         return policy.yield();
 699 }
 700
 701 static CFTypeRef installerPolicy()
 702 {
 703         CFRef<SecPolicyRef> base = SecPolicyCreateBasicX509();
 704         CFRef<SecPolicyRef> revoc = makeRevocationPolicy();
 705         return makeCFArray(2, base.get(), revoc.get());
 706 }
 707
 708
 709 //
 710 // LaunchServices-layer document open.
 711 // We don't cache those at present. If we ever do, we need to authenticate CoreServicesUIAgent as the source of its risk assessment.
 712 //
 713 void PolicyEngine::evaluateDocOpen(CFURLRef path, SecAssessmentFlags flags, CFDictionaryRef context, CFMutableDictionaryRef result)
 714 {
 715         if (context) {
 716                 FileQuarantine qtn(cfString(path).c_str());
 717                 if (CFDictionaryGetValue(context, kSecAssessmentContextKeyPrimarySignature) == kCFBooleanTrue) {
 718                         // Client requests that we focus on the code signature on this document and report on that.
 719                         // On this path, we care about the (code) signature on the document, not its risk assessment,
 720                         // and any exception is reported as a primary error.
 721                         if (qtn.flag(QTN_FLAG_ASSESSMENT_OK)) {
 722                                 // previously added by user - hacked to say no/no usable signature to trigger proper DMG processing in XProtect
 723                                 cfadd(result, "{%O=#F}", kSecAssessmentAssessmentVerdict);
 724                 addAuthority(flags, result, "no usable signature");
 725                                 return;
 726                         }
 727                         evaluateCode(path, kAuthorityOpenDoc, flags, context, result, true);
 728                         return;
 729                 }
 730                 if (CFStringRef riskCategory = CFStringRef(CFDictionaryGetValue(context, kLSDownloadRiskCategoryKey))) {
 731
 732                         if (CFEqual(riskCategory, kLSRiskCategorySafe)
 733                                 || CFEqual(riskCategory, kLSRiskCategoryNeutral)
 734                                 || CFEqual(riskCategory, kLSRiskCategoryUnknown)
 735                                 || CFEqual(riskCategory, kLSRiskCategoryMayContainUnsafeExecutable)) {
 736                                 cfadd(result, "{%O=#T}", kSecAssessmentAssessmentVerdict);
 737                                 addAuthority(flags, result, "_XProtect");
 738                         } else if (qtn.flag(QTN_FLAG_HARD)) {
 739                                 MacOSError::throwMe(errSecCSFileHardQuarantined);
 740                         } else if (qtn.flag(QTN_FLAG_ASSESSMENT_OK)) {
 741                                 // previously added by user
 742                                 cfadd(result, "{%O=#T}", kSecAssessmentAssessmentVerdict);
 743                                 addAuthority(flags, result, "Prior Assessment");
 744                         } else if (!overrideAssessment(flags)) {                // no need to do more work if we're off
 745                                 try {
 746                                         evaluateCode(path, kAuthorityOpenDoc, flags, context, result, true);
 747                                 } catch (...) {
 748                                         // some documents can't be code signed, so this may be quite benign
 749                                 }
 750                         }
 751                         if (CFDictionaryGetValue(result, kSecAssessmentAssessmentVerdict) == NULL) {    // no code signature to help us out
 752                            cfadd(result, "{%O=#F}", kSecAssessmentAssessmentVerdict);
 753                            addAuthority(flags, result, "_XProtect");
 754                         }
 755                         addToAuthority(result, kLSDownloadRiskCategoryKey, riskCategory);
 756                         return;
 757                 }
 758         }
 759         // insufficient information from LS - deny by default
 760         cfadd(result, "{%O=#F}", kSecAssessmentAssessmentVerdict);
 761         addAuthority(flags, result, "Insufficient Context");
 762 }
 763
 764
 765 //
 766 // Result-creation helpers
 767 //
 768 void PolicyEngine::addAuthority(SecAssessmentFlags flags, CFMutableDictionaryRef parent, const char *label, SQLite::int64 row, CFTypeRef cacheInfo, bool weak, uint64_t ruleFlags)
 769 {
 770         CFRef<CFMutableDictionaryRef> auth = makeCFMutableDictionary();
 771         if (label && label[0])
 772                 cfadd(auth, "{%O=%s}", kSecAssessmentAssessmentSource, label);
 773         if (row)
 774                 CFDictionaryAddValue(auth, kSecAssessmentAssessmentAuthorityRow, CFTempNumber(row));
 775         if (overrideAssessment(flags))
 776                 CFDictionaryAddValue(auth, kSecAssessmentAssessmentAuthorityOverride, kDisabledOverride);
 777         if (cacheInfo)
 778                 CFDictionaryAddValue(auth, kSecAssessmentAssessmentFromCache, cacheInfo);
 779         CFDictionaryAddValue(auth, kSecAssessmentAssessmentAuthorityFlags, CFTempNumber(ruleFlags));
 780         if (weak) {
 781                 CFDictionaryAddValue(auth, kSecAssessmentAssessmentWeakSignature, kCFBooleanTrue);
 782                 CFDictionaryReplaceValue(parent, kSecAssessmentAssessmentAuthority, auth);
 783         } else {
 784                 CFDictionaryAddValue(parent, kSecAssessmentAssessmentAuthority, auth);
 785         }
 786 }
 787
 788 void PolicyEngine::addToAuthority(CFMutableDictionaryRef parent, CFStringRef key, CFTypeRef value)
 789 {
 790         CFMutableDictionaryRef authority = CFMutableDictionaryRef(CFDictionaryGetValue(parent, kSecAssessmentAssessmentAuthority));
 791         assert(authority);
 792         CFDictionaryAddValue(authority, key, value);
 793 }
 794
 795
 796 //
 797 // Add a rule to the policy database
 798 //
 799 CFDictionaryRef PolicyEngine::add(CFTypeRef inTarget, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context)
 800 {
 801         // default type to execution
 802         if (type == kAuthorityInvalid)
 803                 type = kAuthorityExecute;
 804
 805         authorizeUpdate(flags, context);
 806         CFDictionary ctx(context, errSecCSInvalidAttributeValues);
 807         CFCopyRef<CFTypeRef> target = inTarget;
 808         CFRef<CFDataRef> bookmark = NULL;
 809         std::string filter_unsigned;
 810
 811         switch (type) {
 812         case kAuthorityExecute:
 813                 normalizeTarget(target, type, ctx, &filter_unsigned);
 814                 // bookmarks are untrusted and just a hint to callers
 815                 bookmark = ctx.get<CFDataRef>(kSecAssessmentRuleKeyBookmark);
 816                 break;
 817         case kAuthorityInstall:
 818                 if (inTarget && CFGetTypeID(inTarget) == CFURLGetTypeID()) {
 819                         // no good way to turn an installer file into a requirement. Pretend to succeeed so caller proceeds
 820                         CFRef<CFArrayRef> properties = makeCFArray(2, kCFURLFileResourceIdentifierKey, kCFURLContentModificationDateKey);
 821                         CFRef<CFErrorRef> error;
 822                         CFURLBookmarkCreationOptions options = kCFURLBookmarkCreationDoNotIncludeSandboxExtensionsMask | kCFURLBookmarkCreationMinimalBookmarkMask;
 823                         if (CFRef<CFDataRef> bookmark = CFURLCreateBookmarkData(NULL, CFURLRef(inTarget), options, properties, NULL, &error.aref())) {
 824                                 UnixPlusPlus::AutoFileDesc fd(lastApprovedFile, O_WRONLY | O_CREAT | O_TRUNC);
 825                                 fd.write(CFDataGetBytePtr(bookmark), CFDataGetLength(bookmark));
 826                                 return NULL;
 827                         }
 828                 }
 829                 break;
 830         case kAuthorityOpenDoc:
 831                 // handle document-open differently: use quarantine flags for whitelisting
 832                 if (!target || CFGetTypeID(target) != CFURLGetTypeID()) // can only "add" file paths
 833                         MacOSError::throwMe(errSecCSInvalidObjectRef);
 834                 try {
 835                         std::string spath = cfString(target.as<CFURLRef>());
 836                         FileQuarantine qtn(spath.c_str());
 837                         qtn.setFlag(QTN_FLAG_ASSESSMENT_OK);
 838                         qtn.applyTo(spath.c_str());
 839                 } catch (const CommonError &error) {
 840                         // could not set quarantine flag - report qualified success
 841                         return cfmake<CFDictionaryRef>("{%O=%O,'assessment:error'=%d}",
 842                                 kSecAssessmentAssessmentAuthorityOverride, CFSTR("error setting quarantine"), error.osStatus());
 843                 } catch (...) {
 844                         return cfmake<CFDictionaryRef>("{%O=%O}", kSecAssessmentAssessmentAuthorityOverride, CFSTR("unable to set quarantine"));
 845                 }
 846                 return NULL;
 847         }
 848
 849         // if we now have anything else, we're busted
 850         if (!target || CFGetTypeID(target) != SecRequirementGetTypeID())
 851                 MacOSError::throwMe(errSecCSInvalidObjectRef);
 852
 853         double priority = 0;
 854         string label;
 855         bool allow = true;
 856         double expires = never;
 857         string remarks;
 858         SQLite::uint64 dbFlags = kAuthorityFlagWhitelistV2 | kAuthorityFlagWhitelistSHA256;
 859
 860         if (CFNumberRef pri = ctx.get<CFNumberRef>(kSecAssessmentUpdateKeyPriority))
 861                 CFNumberGetValue(pri, kCFNumberDoubleType, &priority);
 862         if (CFStringRef lab = ctx.get<CFStringRef>(kSecAssessmentUpdateKeyLabel))
 863                 label = cfString(lab);
 864         if (CFDateRef time = ctx.get<CFDateRef>(kSecAssessmentUpdateKeyExpires))
 865                 // we're using Julian dates here; convert from CFDate
 866                 expires = dateToJulian(time);
 867         if (CFBooleanRef allowing = ctx.get<CFBooleanRef>(kSecAssessmentUpdateKeyAllow))
 868                 allow = allowing == kCFBooleanTrue;
 869         if (CFStringRef rem = ctx.get<CFStringRef>(kSecAssessmentUpdateKeyRemarks))
 870                 remarks = cfString(rem);
 871
 872         CFRef<CFStringRef> requirementText;
 873         MacOSError::check(SecRequirementCopyString(target.as<SecRequirementRef>(), kSecCSDefaultFlags, &requirementText.aref()));
 874         SQLite::Transaction xact(*this, SQLite3::Transaction::deferred, "add_rule");
 875         SQLite::Statement insert(*this,
 876                 "INSERT INTO authority (type, allow, requirement, priority, label, expires, filter_unsigned, remarks, flags)"
 877                 "       VALUES (:type, :allow, :requirement, :priority, :label, :expires, :filter_unsigned, :remarks, :flags);");
 878         insert.bind(":type").integer(type);
 879         insert.bind(":allow").integer(allow);
 880         insert.bind(":requirement") = requirementText.get();
 881         insert.bind(":priority") = priority;
 882         if (!label.empty())
 883                 insert.bind(":label") = label;
 884         insert.bind(":expires") = expires;
 885         insert.bind(":filter_unsigned") = filter_unsigned.empty() ? NULL : filter_unsigned.c_str();
 886         if (!remarks.empty())
 887                 insert.bind(":remarks") = remarks;
 888         insert.bind(":flags").integer(dbFlags);
 889         insert.execute();
 890         SQLite::int64 newRow = this->lastInsert();
 891         if (bookmark) {
 892                 SQLite::Statement bi(*this, "INSERT INTO bookmarkhints (bookmark, authority) VALUES (:bookmark, :authority)");
 893                 bi.bind(":bookmark") = CFDataRef(bookmark);
 894                 bi.bind(":authority").integer(newRow);
 895                 bi.execute();
 896         }
 897         this->purgeObjects(priority);
 898         xact.commit();
 899         notify_post(kNotifySecAssessmentUpdate);
 900         return cfmake<CFDictionaryRef>("{%O=%d}", kSecAssessmentUpdateKeyRow, newRow);
 901 }
 902
 903
 904 CFDictionaryRef PolicyEngine::remove(CFTypeRef target, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context)
 905 {
 906         if (type == kAuthorityOpenDoc) {
 907                 // handle document-open differently: use quarantine flags for whitelisting
 908                 authorizeUpdate(flags, context);
 909                 if (!target || CFGetTypeID(target) != CFURLGetTypeID())
 910                         MacOSError::throwMe(errSecCSInvalidObjectRef);
 911                 std::string spath = cfString(CFURLRef(target)).c_str();
 912                 FileQuarantine qtn(spath.c_str());
 913                 qtn.clearFlag(QTN_FLAG_ASSESSMENT_OK);
 914                 qtn.applyTo(spath.c_str());
 915                 return NULL;
 916         }
 917         return manipulateRules("DELETE FROM authority", target, type, flags, context, true);
 918 }
 919
 920 CFDictionaryRef PolicyEngine::enable(CFTypeRef target, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context, bool authorize)
 921 {
 922         return manipulateRules("UPDATE authority SET disabled = 0", target, type, flags, context, authorize);
 923 }
 924
 925 CFDictionaryRef PolicyEngine::disable(CFTypeRef target, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context, bool authorize)
 926 {
 927         return manipulateRules("UPDATE authority SET disabled = 1", target, type, flags, context, authorize);
 928 }
 929
 930 CFDictionaryRef PolicyEngine::find(CFTypeRef target, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context)
 931 {
 932     //for privacy reasons we only want to allow the admin to list the database
 933     authorizeUpdate(flags, context);
 934
 935         SQLite::Statement query(*this);
 936         selectRules(query, "SELECT scan_authority.id, scan_authority.type, scan_authority.requirement, scan_authority.allow, scan_authority.label, scan_authority.priority, scan_authority.remarks, scan_authority.expires, scan_authority.disabled, bookmarkhints.bookmark FROM scan_authority LEFT OUTER JOIN bookmarkhints ON scan_authority.id = bookmarkhints.authority",
 937                 "scan_authority", target, type, flags, context,
 938                 " ORDER BY priority DESC");
 939         CFRef<CFMutableArrayRef> found = makeCFMutableArray(0);
 940         while (query.nextRow()) {
 941                 SQLite::int64 id = query[0];
 942                 int type = int(query[1]);
 943                 const char *requirement = query[2];
 944                 int allow = int(query[3]);
 945                 const char *label = query[4];
 946                 double priority = query[5];
 947                 const char *remarks = query[6];
 948                 double expires = query[7];
 949                 int disabled = int(query[8]);
 950                 CFRef<CFDataRef> bookmark = query[9].data();
 951                 CFRef<CFMutableDictionaryRef> rule = makeCFMutableDictionary(5,
 952                         kSecAssessmentRuleKeyID, CFTempNumber(id).get(),
 953                         kSecAssessmentRuleKeyType, CFRef<CFStringRef>(typeNameFor(type)).get(),
 954                         kSecAssessmentRuleKeyRequirement, CFTempString(requirement).get(),
 955                         kSecAssessmentRuleKeyAllow, allow ? kCFBooleanTrue : kCFBooleanFalse,
 956                         kSecAssessmentRuleKeyPriority, CFTempNumber(priority).get()
 957                         );
 958                 if (label)
 959                         CFDictionaryAddValue(rule, kSecAssessmentRuleKeyLabel, CFTempString(label));
 960                 if (remarks)
 961                         CFDictionaryAddValue(rule, kSecAssessmentRuleKeyRemarks, CFTempString(remarks));
 962                 if (expires != never)
 963                         CFDictionaryAddValue(rule, kSecAssessmentRuleKeyExpires, CFRef<CFDateRef>(julianToDate(expires)));
 964                 if (disabled)
 965                         CFDictionaryAddValue(rule, kSecAssessmentRuleKeyDisabled, CFTempNumber(disabled));
 966                 if (bookmark)
 967                         CFDictionaryAddValue(rule, kSecAssessmentRuleKeyBookmark, bookmark);
 968                 CFArrayAppendValue(found, rule);
 969         }
 970         if (CFArrayGetCount(found) == 0)
 971                 MacOSError::throwMe(errSecCSNoMatches);
 972         return cfmake<CFDictionaryRef>("{%O=%O}", kSecAssessmentUpdateKeyFound, found.get());
 973 }
 974
 975
 976 CFDictionaryRef PolicyEngine::update(CFTypeRef target, SecAssessmentFlags flags, CFDictionaryRef context)
 977 {
 978         // update GKE
 979         installExplicitSet(gkeAuthFile, gkeSigsFile);
 980
 981         AuthorityType type = typeFor(context, kAuthorityInvalid);
 982         CFStringRef edit = CFStringRef(CFDictionaryGetValue(context, kSecAssessmentContextKeyUpdate));
 983         CFDictionaryRef result;
 984         if (CFEqual(edit, kSecAssessmentUpdateOperationAdd))
 985                 result = this->add(target, type, flags, context);
 986         else if (CFEqual(edit, kSecAssessmentUpdateOperationRemove))
 987                 result = this->remove(target, type, flags, context);
 988         else if (CFEqual(edit, kSecAssessmentUpdateOperationEnable))
 989                 result = this->enable(target, type, flags, context, true);
 990         else if (CFEqual(edit, kSecAssessmentUpdateOperationDisable))
 991                 result = this->disable(target, type, flags, context, true);
 992         else if (CFEqual(edit, kSecAssessmentUpdateOperationFind))
 993                 result = this->find(target, type, flags, context);
 994         else
 995                 MacOSError::throwMe(errSecCSInvalidAttributeValues);
 996         if (result == NULL)
 997                 result = makeCFDictionary(0);           // success, no details
 998         return result;
 999 }
1000
1001
1002 //
1003 // Construct and prepare an SQL query on the authority table, operating on some set of existing authority records.
1004 // In essence, this appends a suitable WHERE clause to the stanza passed and prepares it on the statement given.
1005 //
1006 void PolicyEngine::selectRules(SQLite::Statement &action, std::string phrase, std::string table,
1007         CFTypeRef inTarget, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context, std::string suffix /* = "" */)
1008 {
1009         CFDictionary ctx(context, errSecCSInvalidAttributeValues);
1010         CFCopyRef<CFTypeRef> target = inTarget;
1011         std::string filter_unsigned;    // ignored; used just to trigger ad-hoc signing
1012         normalizeTarget(target, type, ctx, &filter_unsigned);
1013
1014         string label;
1015         if (CFStringRef lab = ctx.get<CFStringRef>(kSecAssessmentUpdateKeyLabel))
1016                 label = cfString(CFStringRef(lab));
1017
1018         if (!target) {
1019                 if (label.empty()) {
1020                         if (type == kAuthorityInvalid) {
1021                                 action.query(phrase + suffix);
1022                         } else {
1023                                 action.query(phrase + " WHERE " + table + ".type = :type" + suffix);
1024                                 action.bind(":type").integer(type);
1025                         }
1026                 } else {        // have label
1027                         if (type == kAuthorityInvalid) {
1028                                 action.query(phrase + " WHERE " + table + ".label = :label" + suffix);
1029                         } else {
1030                                 action.query(phrase + " WHERE " + table + ".type = :type AND " + table + ".label = :label" + suffix);
1031                                 action.bind(":type").integer(type);
1032                         }
1033                         action.bind(":label") = label;
1034                 }
1035         } else if (CFGetTypeID(target) == CFNumberGetTypeID()) {
1036                 action.query(phrase + " WHERE " + table + ".id = :id" + suffix);
1037                 action.bind(":id").integer(cfNumber<uint64_t>(target.as<CFNumberRef>()));
1038         } else if (CFGetTypeID(target) == SecRequirementGetTypeID()) {
1039                 if (type == kAuthorityInvalid)
1040                         type = kAuthorityExecute;
1041                 CFRef<CFStringRef> requirementText;
1042                 MacOSError::check(SecRequirementCopyString(target.as<SecRequirementRef>(), kSecCSDefaultFlags, &requirementText.aref()));
1043                 action.query(phrase + " WHERE " + table + ".type = :type AND " + table + ".requirement = :requirement" + suffix);
1044                 action.bind(":type").integer(type);
1045                 action.bind(":requirement") = requirementText.get();
1046         } else
1047                 MacOSError::throwMe(errSecCSInvalidObjectRef);
1048 }
1049
1050
1051 //
1052 // Execute an atomic change to existing records in the authority table.
1053 //
1054 CFDictionaryRef PolicyEngine::manipulateRules(const std::string &stanza,
1055         CFTypeRef inTarget, AuthorityType type, SecAssessmentFlags flags, CFDictionaryRef context, bool authorize)
1056 {
1057         SQLite::Transaction xact(*this, SQLite3::Transaction::deferred, "rule_change");
1058         SQLite::Statement action(*this);
1059         if (authorize)
1060                 authorizeUpdate(flags, context);
1061         selectRules(action, stanza, "authority", inTarget, type, flags, context);
1062         action.execute();
1063         unsigned int changes = this->changes(); // latch change count
1064         // We MUST purge objects with priority <= MAX(priority of any changed rules);
1065         // but for now we just get lazy and purge them ALL.
1066         if (changes) {
1067                 this->purgeObjects(1.0E100);
1068                 xact.commit();
1069                 notify_post(kNotifySecAssessmentUpdate);
1070                 return cfmake<CFDictionaryRef>("{%O=%d}", kSecAssessmentUpdateKeyCount, changes);
1071         }
1072         // no change; return an error
1073         MacOSError::throwMe(errSecCSNoMatches);
1074 }
1075
1076
1077 //
1078 // Fill in extra information about the originator of cryptographic credentials found - if any
1079 //
1080 void PolicyEngine::setOrigin(CFArrayRef chain, CFMutableDictionaryRef result)
1081 {
1082         if (chain)
1083                 if (CFArrayGetCount(chain) > 0)
1084                         if (SecCertificateRef leaf = SecCertificateRef(CFArrayGetValueAtIndex(chain, 0)))
1085                                 if (CFStringRef summary = SecCertificateCopyLongDescription(NULL, leaf, NULL)) {
1086                                         CFDictionarySetValue(result, kSecAssessmentAssessmentOriginator, summary);
1087                                         CFRelease(summary);
1088                                 }
1089 }
1090
1091
1092 //
1093 // Take an assessment outcome and record it in the object cache
1094 //
1095 void PolicyEngine::recordOutcome(SecStaticCodeRef code, bool allow, AuthorityType type, double expires, SQLite::int64 authority)
1096 {
1097         CFRef<CFDictionaryRef> info;
1098         MacOSError::check(SecCodeCopySigningInformation(code, kSecCSDefaultFlags, &info.aref()));
1099         CFDataRef cdHash = CFDataRef(CFDictionaryGetValue(info, kSecCodeInfoUnique));
1100         assert(cdHash);         // was signed
1101         CFRef<CFURLRef> path;
1102         MacOSError::check(SecCodeCopyPath(code, kSecCSDefaultFlags, &path.aref()));
1103         assert(expires);
1104         SQLite::Transaction xact(*this, SQLite3::Transaction::deferred, "caching");
1105         SQLite::Statement insert(*this,
1106                 "INSERT OR REPLACE INTO object (type, allow, hash, expires, path, authority)"
1107                 "       VALUES (:type, :allow, :hash, :expires, :path,"
1108                 "       CASE :authority WHEN 0 THEN (SELECT id FROM authority WHERE label = 'No Matching Rule') ELSE :authority END"
1109                 "       );");
1110         insert.bind(":type").integer(type);
1111         insert.bind(":allow").integer(allow);
1112         insert.bind(":hash") = cdHash;
1113         insert.bind(":expires") = expires;
1114         insert.bind(":path") = cfString(path);
1115         insert.bind(":authority").integer(authority);
1116         insert.execute();
1117         xact.commit();
1118 }
1119
1120
1121 //
1122 // Record a UI failure record after proper validation of the caller
1123 //
1124 void PolicyEngine::recordFailure(CFDictionaryRef info)
1125 {
1126         CFRef<CFDataRef> infoData = makeCFData(info);
1127         UnixPlusPlus::AutoFileDesc fd(lastRejectFile, O_WRONLY | O_CREAT | O_TRUNC);
1128         fd.write(CFDataGetBytePtr(infoData), CFDataGetLength(infoData));
1129         notify_post(kNotifySecAssessmentRecordingChange);
1130 }
1131
1132
1133 //
1134 // Perform update authorization processing.
1135 // Throws an exception if authorization is denied.
1136 //
1137 static void authorizeUpdate(SecAssessmentFlags flags, CFDictionaryRef context)
1138 {
1139         AuthorizationRef authorization = NULL;
1140
1141         if (context)
1142                 if (CFTypeRef authkey = CFDictionaryGetValue(context, kSecAssessmentUpdateKeyAuthorization))
1143                         if (CFGetTypeID(authkey) == CFDataGetTypeID()) {
1144                                 CFDataRef authdata = CFDataRef(authkey);
1145                                 if (CFDataGetLength(authdata) != sizeof(AuthorizationExternalForm))
1146                                         MacOSError::throwMe(errSecCSInvalidObjectRef);
1147                                 MacOSError::check(AuthorizationCreateFromExternalForm((AuthorizationExternalForm *)CFDataGetBytePtr(authdata), &authorization));
1148                         }
1149         if (authorization == NULL)
1150                 MacOSError::throwMe(errSecCSDBDenied);
1151
1152         AuthorizationItem right[] = {
1153                 { "com.apple.security.assessment.update", 0, NULL, 0 }
1154         };
1155         AuthorizationRights rights = { sizeof(right) / sizeof(right[0]), right };
1156         MacOSError::check(AuthorizationCopyRights(authorization, &rights, NULL,
1157                 kAuthorizationFlagExtendRights | kAuthorizationFlagInteractionAllowed, NULL));
1158
1159         MacOSError::check(AuthorizationFree(authorization, kAuthorizationFlagDefaults));
1160 }
1161
1162
1163 //
1164 // Perform common argument normalizations for update operations
1165 //
1166 void PolicyEngine::normalizeTarget(CFRef<CFTypeRef> &target, AuthorityType type, CFDictionary &context, std::string *signUnsigned)
1167 {
1168         // turn CFURLs into (designated) SecRequirements
1169         if (target && CFGetTypeID(target) == CFURLGetTypeID()) {
1170                 CFRef<SecStaticCodeRef> code;
1171                 CFURLRef path = target.as<CFURLRef>();
1172                 MacOSError::check(SecStaticCodeCreateWithPath(path, kSecCSDefaultFlags, &code.aref()));
1173                 switch (OSStatus rc = SecCodeCopyDesignatedRequirement(code, kSecCSDefaultFlags, (SecRequirementRef *)&target.aref())) {
1174                 case errSecSuccess: {
1175                         // use the *default* DR to avoid unreasonably wide DRs opening up Gatekeeper to attack
1176                         CFRef<CFDictionaryRef> info;
1177                         MacOSError::check(SecCodeCopySigningInformation(code, kSecCSRequirementInformation, &info.aref()));
1178                         target = CFDictionaryGetValue(info, kSecCodeInfoImplicitDesignatedRequirement);
1179                         }
1180                         break;
1181                 case errSecCSUnsigned:
1182                         if (signUnsigned && temporarySigning(code, type, path, kAuthorityFlagWhitelistV2 | kAuthorityFlagWhitelistSHA256)) {    // ad-hoc sign the code temporarily
1183                                 MacOSError::check(SecCodeCopyDesignatedRequirement(code, kSecCSDefaultFlags, (SecRequirementRef *)&target.aref()));
1184                                 *signUnsigned = createWhitelistScreen(code);
1185                                 break;
1186                         }
1187                         MacOSError::check(rc);
1188                 case errSecCSSignatureFailed:
1189                 default:
1190                         MacOSError::check(rc);
1191                 }
1192                 if (context.get(kSecAssessmentUpdateKeyRemarks) == NULL)        {
1193                         // no explicit remarks; add one with the path
1194                         CFRef<CFURLRef> path;
1195                         MacOSError::check(SecCodeCopyPath(code, kSecCSDefaultFlags, &path.aref()));
1196                         CFMutableDictionaryRef dict = makeCFMutableDictionary(context.get());
1197                         CFDictionaryAddValue(dict, kSecAssessmentUpdateKeyRemarks, CFTempString(cfString(path)));
1198                         context.take(dict);
1199                 }
1200                 CFStringRef edit = CFStringRef(context.get(kSecAssessmentContextKeyUpdate));
1201                 if (type == kAuthorityExecute && CFEqual(edit, kSecAssessmentUpdateOperationAdd)) {
1202                         // implicitly whitelist the code
1203                         opaqueWhitelistAdd(code);
1204                 }
1205         }
1206 }
1207
1208 } // end namespace CodeSigning
1209 } // end namespace Security