OSX/libsecurity_codesigning/lib/resources.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,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  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 // resource directory construction and verification
  26 //
  27 #include "resources.h"
  28 #include "csutilities.h"
  29 #include <security_utilities/unix++.h>
  30 #include <security_utilities/debugging.h>
  31 #include <Security/CSCommon.h>
  32 #include <security_utilities/unix++.h>
  33 #include <security_utilities/cfmunge.h>
  34
  35 // These are pretty nasty, but are a quick safe fix
  36 // to pass information down to the gatekeeper collection tool
  37 extern "C" {
  38     int GKBIS_DS_Store_Present;
  39         int GKBIS_Dot_underbar_Present;
  40         int GKBIS_Num_localizations;
  41         int GKBIS_Num_files;
  42         int GKBIS_Num_dirs;
  43         int GKBIS_Num_symlinks;
  44 }
  45
  46 namespace Security {
  47 namespace CodeSigning {
  48
  49
  50 static string removeTrailingSlash(string path)
  51 {
  52         if (path.substr(path.length()-2, 2) == "/.")
  53                 return path.substr(0, path.length()-2);
  54         else if (path.substr(path.length()-1, 1) == "/")
  55                 return path.substr(0, path.length()-1);
  56         else
  57                 return path;
  58 }
  59
  60 //
  61 // Construction and maintainance
  62 //
  63 ResourceBuilder::ResourceBuilder(const std::string &root, const std::string &relBase,
  64         CFDictionaryRef rulesDict, CodeDirectory::HashAlgorithm hashType, bool strict, const MacOSErrorSet& toleratedErrors)
  65         : mHashType(hashType),
  66           mCheckUnreadable(strict && toleratedErrors.find(errSecCSSignatureNotVerifiable) == toleratedErrors.end()),
  67           mCheckUnknownType(strict && toleratedErrors.find(errSecCSResourceNotSupported) == toleratedErrors.end())
  68 {
  69         assert(!root.empty());
  70         char realroot[PATH_MAX];
  71         if (realpath(root.c_str(), realroot) == NULL)
  72                 UnixError::throwMe();
  73         mRoot = realroot;
  74         if (realpath(removeTrailingSlash(relBase).c_str(), realroot) == NULL)
  75                 UnixError::throwMe();
  76         mRelBase = realroot;
  77         if (mRoot != mRelBase && mRelBase != mRoot + "/Contents")
  78                 MacOSError::throwMe(errSecCSInternalError);
  79         const char * paths[2] = { mRoot.c_str(), NULL };
  80         mFTS = fts_open((char * const *)paths, FTS_PHYSICAL | FTS_COMFOLLOW | FTS_NOCHDIR, NULL);
  81         if (!mFTS)
  82                 UnixError::throwMe();
  83         mRawRules = rulesDict;
  84         CFDictionary rules(rulesDict, errSecCSResourceRulesInvalid);
  85         rules.apply(this, &ResourceBuilder::addRule);
  86 }
  87
  88 ResourceBuilder::~ResourceBuilder()
  89 {
  90         for (Rules::iterator it = mRules.begin(); it != mRules.end(); ++it)
  91                 delete *it;
  92         fts_close(mFTS);        // do not check error - it's not worth aborting over (double fault etc.)
  93 }
  94
  95
  96 //
  97 // Parse and add one matching rule
  98 //
  99 void ResourceBuilder::addRule(CFTypeRef key, CFTypeRef value)
 100 {
 101         string pattern = cfString(key, errSecCSResourceRulesInvalid);
 102         unsigned weight = 1;
 103         uint32_t flags = 0;
 104         if (CFGetTypeID(value) == CFBooleanGetTypeID()) {
 105                 if (value == kCFBooleanFalse)
 106                         flags |= omitted;
 107         } else {
 108                 CFDictionary rule(value, errSecCSResourceRulesInvalid);
 109                 if (CFNumberRef weightRef = rule.get<CFNumberRef>("weight"))
 110                         weight = cfNumber<unsigned int>(weightRef);
 111                 if (CFBooleanRef omitRef = rule.get<CFBooleanRef>("omit"))
 112                         if (omitRef == kCFBooleanTrue)
 113                                 flags |= omitted;
 114                 if (CFBooleanRef optRef = rule.get<CFBooleanRef>("optional"))
 115                         if (optRef == kCFBooleanTrue)
 116                                 flags |= optional;
 117                 if (CFBooleanRef nestRef = rule.get<CFBooleanRef>("nested"))
 118                         if (nestRef == kCFBooleanTrue)
 119                                 flags |= nested;
 120         }
 121         addRule(new Rule(pattern, weight, flags));
 122 }
 123
 124 static bool findStringEndingNoCase(const char *path, const char * end)
 125 {
 126     size_t len_path = strlen(path);
 127     size_t len_end = strlen(end);
 128
 129     if (len_path >= len_end) {
 130         return strcasecmp(path + (len_path - len_end), end) == 0;
 131     } else
 132         return false;
 133 }
 134
 135 //
 136 // Locate the next non-ignored file, look up its rule, and return it.
 137 // Returns NULL when we're out of files.
 138 //
 139 void ResourceBuilder::scan(Scanner next)
 140 {
 141         bool first = true;
 142
 143         while (FTSENT *ent = fts_read(mFTS)) {
 144                 static const char ds_store[] = ".DS_Store";
 145                 const char *relpath = ent->fts_path + mRoot.size() + 1; // skip prefix + "/"
 146                 std::string rp;
 147                 if (mRelBase != mRoot) {
 148                         assert(mRelBase == mRoot + "/Contents");
 149                         rp = "../" + string(relpath);
 150                         if (rp.substr(0, 12) == "../Contents/")
 151                                 rp = rp.substr(12);
 152                         relpath = rp.c_str();
 153                 }
 154                 switch (ent->fts_info) {
 155                 case FTS_F:
 156                         secdebug("rdirenum", "file %s", ent->fts_path);
 157                         GKBIS_Num_files++;
 158
 159                         // These are checks for the gatekeeper collection
 160                         static const char underbar[] = "._";
 161                         if (strncasecmp(ent->fts_name, underbar, strlen(underbar)) == 0)
 162                                 GKBIS_Dot_underbar_Present++;
 163
 164                         if (strcasecmp(ent->fts_name, ds_store) == 0)
 165                                 GKBIS_DS_Store_Present++;
 166
 167                         if (Rule *rule = findRule(relpath))
 168                                 if (!(rule->flags & (omitted | exclusion)))
 169                                         next(ent, rule->flags, string(relpath), rule);
 170                         break;
 171                 case FTS_SL:
 172                         // symlinks cannot ever be nested code, so quietly convert to resource file
 173                         secdebug("rdirenum", "symlink %s", ent->fts_path);
 174                         GKBIS_Num_symlinks++;
 175
 176                         if (strcasecmp(ent->fts_name, ds_store) == 0)
 177                                 MacOSError::throwMe(errSecCSDSStoreSymlink);
 178
 179                         if (Rule *rule = findRule(relpath))
 180                                 if (!(rule->flags & (omitted | exclusion)))
 181                                         next(ent, rule->flags & ~nested, string(relpath), rule);
 182                         break;
 183                 case FTS_D:
 184                         secdebug("rdirenum", "entering %s", ent->fts_path);
 185                         GKBIS_Num_dirs++;
 186
 187                         if (!first) {   // skip root directory (relpath invalid)
 188                                 if (Rule *rule = findRule(relpath)) {
 189                                         if (rule->flags & nested) {
 190                                                 if (strchr(ent->fts_name, '.')) {       // nested, has extension -> treat as nested bundle
 191                                                         next(ent, rule->flags, string(relpath), rule);
 192                                                         fts_set(mFTS, ent, FTS_SKIP);
 193                                                 }
 194                                         } else if (rule->flags & exclusion) {   // exclude the whole directory
 195                                                 fts_set(mFTS, ent, FTS_SKIP);
 196                                         }
 197                                         // else treat as normal directory and descend into it
 198                                 }
 199                         }
 200                         // Report the number of localizations
 201                         if (findStringEndingNoCase(ent->fts_name, ".lproj"))
 202                                 GKBIS_Num_localizations++;
 203                         first = false;
 204
 205                         break;
 206                 case FTS_DP:
 207                         secdebug("rdirenum", "leaving %s", ent->fts_path);
 208                         break;
 209                 case FTS_DNR:
 210                         secdebug("rdirenum", "cannot read directory %s", ent->fts_path);
 211                         if (mCheckUnreadable)
 212                                 MacOSError::throwMe(errSecCSSignatureNotVerifiable);
 213                         break;
 214                 default:
 215                         secdebug("rdirenum", "type %d (errno %d): %s",
 216                                 ent->fts_info, ent->fts_errno, ent->fts_path);
 217                         if (mCheckUnknownType)
 218                                 MacOSError::throwMe(errSecCSResourceNotSupported);
 219                         break;
 220                 }
 221         }
 222 }
 223
 224
 225 //
 226 // Check a single for for inclusion in the resource envelope
 227 //
 228 bool ResourceBuilder::includes(string path) const
 229 {
 230         // process first-directory exclusions
 231         size_t firstslash = path.find('/');
 232         if (firstslash != string::npos)
 233                 if (Rule *rule = findRule(path.substr(0, firstslash)))
 234                         if (rule->flags & exclusion)
 235                                 return rule->flags & softTarget;
 236
 237         // process full match
 238         if (Rule *rule = findRule(path))
 239                 return !(rule->flags & (omitted | exclusion)) || (rule->flags & softTarget);
 240         else
 241                 return false;
 242 }
 243
 244
 245 //
 246 // Find the best-matching resource rule for an alleged resource file.
 247 // Returns NULL if no rule matches, or an exclusion rule applies.
 248 //
 249 ResourceBuilder::Rule *ResourceBuilder::findRule(string path) const
 250 {
 251         Rule *bestRule = NULL;
 252         secdebug("rscan", "test %s", path.c_str());
 253         for (Rules::const_iterator it = mRules.begin(); it != mRules.end(); ++it) {
 254                 Rule *rule = *it;
 255                 secdebug("rscan", "try %s", rule->source.c_str());
 256                 if (rule->match(path.c_str())) {
 257                         secdebug("rscan", "match");
 258                         if (rule->flags & exclusion) {
 259                                 secdebug("rscan", "excluded");
 260                                 return rule;
 261                         }
 262                         if (!bestRule || rule->weight > bestRule->weight)
 263                                 bestRule = rule;
 264                 }
 265         }
 266         secdebug("rscan", "choosing %s (%d,0x%x)",
 267                 bestRule ? bestRule->source.c_str() : "NOTHING",
 268                 bestRule ? bestRule->weight : 0,
 269                 bestRule ? bestRule->flags : 0);
 270         return bestRule;
 271 }
 272
 273
 274 //
 275 // Hash a file and return a CFDataRef with the hash
 276 //
 277 CFDataRef ResourceBuilder::hashFile(const char *path) const
 278 {
 279         UnixPlusPlus::AutoFileDesc fd(path);
 280         fd.fcntl(F_NOCACHE, true);              // turn off page caching (one-pass)
 281         MakeHash<ResourceBuilder> hasher(this);
 282         hashFileData(fd, hasher.get());
 283         Hashing::Byte digest[hasher->digestLength()];
 284         hasher->finish(digest);
 285         return CFDataCreate(NULL, digest, sizeof(digest));
 286 }
 287
 288
 289 //
 290 // Regex matching objects
 291 //
 292 ResourceBuilder::Rule::Rule(const std::string &pattern, unsigned w, uint32_t f)
 293         : weight(w), flags(f), source(pattern)
 294 {
 295         if (::regcomp(this, pattern.c_str(), REG_EXTENDED | REG_NOSUB)) //@@@ REG_ICASE?
 296                 MacOSError::throwMe(errSecCSResourceRulesInvalid);
 297         secdebug("csresource", "%p rule %s added (weight %d, flags 0x%x)",
 298                 this, pattern.c_str(), w, f);
 299 }
 300
 301 ResourceBuilder::Rule::~Rule()
 302 {
 303         ::regfree(this);
 304 }
 305
 306 bool ResourceBuilder::Rule::match(const char *s) const
 307 {
 308         switch (::regexec(this, s, 0, NULL, 0)) {
 309         case 0:
 310                 return true;
 311         case REG_NOMATCH:
 312                 return false;
 313         default:
 314                 MacOSError::throwMe(errSecCSResourceRulesInvalid);
 315         }
 316 }
 317
 318
 319 std::string ResourceBuilder::escapeRE(const std::string &s)
 320 {
 321         string r;
 322         for (string::const_iterator it = s.begin(); it != s.end(); ++it) {
 323                 char c = *it;
 324                 if (strchr("\\[]{}().+*?", c))
 325                         r.push_back('\\');
 326                 r.push_back(c);
 327         }
 328         return r;
 329 }
 330
 331
 332 //
 333 // Resource Seals
 334 //
 335 ResourceSeal::ResourceSeal(CFTypeRef it)
 336         : mDict(NULL), mHash(NULL), mRequirement(NULL), mLink(NULL), mFlags(0)
 337 {
 338         if (it == NULL)
 339                 MacOSError::throwMe(errSecCSResourcesInvalid);
 340         if (CFGetTypeID(it) == CFDataGetTypeID()) {
 341                 mHash = CFDataRef(it);
 342         } else {
 343                 int optional = 0;
 344                 mDict = CFDictionaryRef(it);
 345                 bool err;
 346                 if (CFDictionaryGetValue(mDict, CFSTR("requirement")))
 347                         err = !cfscan(mDict, "{requirement=%SO,?optional=%B}", &mRequirement, &optional);
 348                 else if (CFDictionaryGetValue(mDict, CFSTR("symlink")))
 349                         err = !cfscan(mDict, "{symlink=%SO,?optional=%B}", &mLink, &optional);
 350                 else
 351                         err = !cfscan(mDict, "{hash=%XO,?optional=%B}", &mHash, &optional);
 352                 if (err)
 353                         MacOSError::throwMe(errSecCSResourcesInvalid);
 354                 if (optional)
 355                         mFlags |= ResourceBuilder::optional;
 356                 if (mRequirement)
 357                         mFlags |= ResourceBuilder::nested;
 358         }
 359 }
 360
 361
 362 } // end namespace CodeSigning
 363 } // end namespace Security