OSX/libsecurity_codesigning/lib/diskrep.cpp

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  10  * http://www.opensource.apple.com/apsl/ and read it before using this
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  23
  24 //
  25 // diskrep - disk representations of code
  26 //
  27 #include "diskrep.h"
  28 #include <sys/stat.h>
  29 #include <CoreFoundation/CFBundlePriv.h>
  30
  31 // specific disk representations created by the bestGuess() function
  32 #include "filediskrep.h"
  33 #include "bundlediskrep.h"
  34 #include "slcrep.h"
  35 #if TARGET_OS_OSX
  36 #include "diskimagerep.h"
  37 #endif
  38
  39 namespace Security {
  40 namespace CodeSigning {
  41
  42 using namespace UnixPlusPlus;
  43
  44
  45 //
  46 // Abstract features
  47 //
  48 DiskRep::DiskRep()
  49 {
  50 }
  51
  52 DiskRep::~DiskRep()
  53 {
  54         CODESIGN_DISKREP_DESTROY(this);
  55 }
  56
  57
  58 //
  59 // Normal DiskReps are their own base.
  60 //
  61 DiskRep *DiskRep::base()
  62 {
  63         return this;
  64 }
  65
  66
  67 //
  68 // By default, DiskReps are read-only.
  69 //
  70 DiskRep::Writer *DiskRep::writer()
  71 {
  72         MacOSError::throwMe(errSecCSUnimplemented);
  73 }
  74
  75
  76 void DiskRep::Writer::addDiscretionary(CodeDirectory::Builder &)
  77 {
  78         // do nothing
  79 }
  80
  81 //
  82 // Given a file system path, come up with the most likely correct
  83 // disk representation for what's there.
  84 // This is, strictly speaking, a heuristic that could be fooled - there's
  85 // no fool-proof rule for figuring this out. But we'd expect this to work
  86 // fine in ordinary use. If you happen to know what you're looking at
  87 // (say, a bundle), then just create the suitable subclass of DiskRep directly.
  88 // That's quite legal.
  89 // The optional context argument can provide additional information that guides the guess.
  90 //
  91 DiskRep *DiskRep::bestGuess(const char *path, const Context *ctx)
  92 {
  93         try {
  94                 if (!(ctx && ctx->fileOnly)) {
  95                         struct stat st;
  96                         if (::stat(path, &st))
  97                                 UnixError::throwMe();
  98
  99                         // if it's a directory, assume it's a bundle
 100                         if ((st.st_mode & S_IFMT) == S_IFDIR)   // directory - assume bundle
 101                                 return new BundleDiskRep(path, ctx);
 102
 103                         // see if it's the main executable of a recognized bundle
 104                         if (CFRef<CFURLRef> pathURL = makeCFURL(path))
 105                                 if (CFRef<CFBundleRef> bundle = _CFBundleCreateWithExecutableURLIfMightBeBundle(NULL, pathURL))
 106                                                 return new BundleDiskRep(bundle, ctx);
 107                 }
 108
 109                 // try the various single-file representations
 110                 AutoFileDesc fd(path, O_RDONLY);
 111                 if (MachORep::candidate(fd))
 112                         return new MachORep(path, ctx);
 113 #if TARGET_OS_OSX
 114                 if (DiskImageRep::candidate(fd))
 115                         return new DiskImageRep(path);
 116 #endif
 117                 if (DYLDCacheRep::candidate(fd))
 118                         return new DYLDCacheRep(path);
 119
 120                 // ultimate fallback - the generic file representation
 121                 return new FileDiskRep(path);
 122
 123         } catch (const CommonError &error) {
 124                 switch (error.unixError()) {
 125                 case ENOENT:
 126                         MacOSError::throwMe(errSecCSStaticCodeNotFound);
 127                 default:
 128                         throw;
 129                 }
 130         }
 131 }
 132
 133
 134 DiskRep *DiskRep::bestFileGuess(const char *path, const Context *ctx)
 135 {
 136         Context dctx;
 137         if (ctx)
 138                 dctx = *ctx;
 139         dctx.fileOnly = true;
 140         return bestGuess(path, &dctx);
 141 }
 142
 143
 144 //
 145 // Given a main executable known to be a Mach-O binary, and an offset into
 146 // the file of the actual architecture desired (of a Universal file),
 147 // produce a suitable MachORep.
 148 // This function does not consider non-MachO binaries. It does however handle
 149 // bundles with Mach-O main executables correctly.
 150 //
 151 DiskRep *DiskRep::bestGuess(const char *path, size_t archOffset)
 152 {
 153         try {
 154                 // is it the main executable of a bundle?
 155                 if (CFRef<CFURLRef> pathURL = makeCFURL(path))
 156                         if (CFRef<CFBundleRef> bundle = _CFBundleCreateWithExecutableURLIfMightBeBundle(NULL, pathURL)) {
 157                                 Context ctx; ctx.offset = archOffset;
 158                                 return new BundleDiskRep(bundle, &ctx); // ask bundle to make bundle-with-MachO-at-offset
 159                         }
 160                 // else, must be a Mach-O binary
 161                 Context ctx; ctx.offset = archOffset;
 162                 return new MachORep(path, &ctx);
 163         } catch (const CommonError &error) {
 164                 switch (error.unixError()) {
 165                 case ENOENT:
 166                         MacOSError::throwMe(errSecCSStaticCodeNotFound);
 167                 default:
 168                         throw;
 169                 }
 170         }
 171 }
 172
 173
 174 //
 175 // Default behaviors of DiskRep
 176 //
 177 string DiskRep::resourcesRootPath()
 178 {
 179         return "";              // has no resources directory
 180 }
 181
 182 void DiskRep::adjustResources(ResourceBuilder &builder)
 183 {
 184         // do nothing
 185 }
 186
 187 void DiskRep::prepareForSigning(SigningContext &state)
 188 {
 189         // do nothing
 190 }
 191
 192 Universal *DiskRep::mainExecutableImage()
 193 {
 194         return NULL;    // no Mach-O executable
 195 }
 196
 197 size_t DiskRep::signingBase()
 198 {
 199         return 0;               // whole file (start at beginning)
 200 }
 201
 202 size_t DiskRep::execSegBase(const Architecture *)
 203 {
 204         return 0;               // whole file (start at beginning)
 205 }
 206
 207 CFArrayRef DiskRep::modifiedFiles()
 208 {
 209         // by default, claim (just) the main executable modified
 210         CFRef<CFURLRef> mainURL = makeCFURL(mainExecutablePath());
 211         return makeCFArray(1, mainURL.get());
 212 }
 213
 214 void DiskRep::flush()
 215 {
 216         // nothing cached
 217 }
 218
 219 CFDictionaryRef DiskRep::diskRepInformation()
 220 {
 221     return NULL;
 222 }
 223
 224 CFDictionaryRef DiskRep::defaultResourceRules(const SigningContext &)
 225 {
 226         return NULL;    // none
 227 }
 228
 229 const Requirements *DiskRep::defaultRequirements(const Architecture *, const SigningContext &)
 230 {
 231         return NULL;    // none
 232 }
 233
 234 size_t DiskRep::pageSize(const SigningContext &)
 235 {
 236         return monolithicPageSize;      // unpaged (monolithic)
 237 }
 238
 239
 240 void DiskRep::strictValidate(const CodeDirectory*, const ToleratedErrors& tolerated, SecCSFlags flags)
 241 {
 242         if (flags & kSecCSRestrictToAppLike)
 243                 if (tolerated.find(errSecCSNotAppLike) == tolerated.end())
 244                         MacOSError::throwMe(errSecCSNotAppLike);
 245 }
 246
 247 CFArrayRef DiskRep::allowedResourceOmissions()
 248 {
 249         return NULL;
 250 }
 251
 252
 253 //
 254 // Given some string (usually a pathname), derive a suggested signing identifier
 255 // in a canonical way (so there's some consistency).
 256 //
 257 // This is a heuristic. First we lop off any leading directories and final (non-numeric)
 258 // extension. Then we walk backwards, eliminating numeric extensions except the first one.
 259 // Thus, libfrotz7.3.5.dylib becomes libfrotz7, mumble.77.plugin becomes mumble.77,
 260 // and rumble.rb becomes rumble. This isn't perfect, but it ought to handle 98%+ of
 261 // the common varieties out there. Specify an explicit identifier for the oddballs.
 262 //
 263 // This is called by the various recommendedIdentifier() methods, who are
 264 // free to modify or override it.
 265 //
 266 // Note: We use strchr("...") instead of is*() here because we do not
 267 // wish to be influenced by locale settings.
 268 //
 269 std::string DiskRep::canonicalIdentifier(const std::string &name)
 270 {
 271         string s = name;
 272         string::size_type p;
 273
 274         // lop off any directory prefixes
 275         if ((p = s.rfind('/')) != string::npos)
 276                 s = s.substr(p+1);
 277
 278         // remove any final extension (last dot) unless it's numeric
 279         if ((p = s.rfind('.')) != string::npos && !strchr("0123456789", s[p+1]))
 280                 s = s.substr(0, p);
 281
 282         // eat numeric suffixes except the first one; roughly:
 283         // foo.2.3.4 => foo.2, foo2.3 => foo2, foo.9 => foo.9, foo => foo
 284         if (strchr("0123456789.", s[0]))                        // starts with digit or .
 285                 return s;                                                               // ... so don't mess with it
 286         p = s.size()-1;
 287         // foo3.5^, foo.3.5^, foo3^, foo.3^, foo^
 288         while (strchr("0123456789.", s[p]))
 289                 p--;
 290         // fo^o3.5, fo^o.3.5, fo^o3, fo^o.3, fo^o
 291         p++;
 292         // foo^3.5, foo^.3.5, foo^3, foo^.3, foo^
 293         if (s[p] == '.')
 294                 p++;
 295         // foo^3.5, foo.^3.5, foo^3, foo.^3, foo^
 296         while (p < s.size() && strchr("0123456789", s[p]))
 297                 p++;
 298         // foo3^.5, foo.3^.5, foo3^, foo.3^, foo^
 299         return s.substr(0, p);
 300 }
 301
 302 void DiskRep::registerStapledTicket()
 303 { /* do nothing */ }
 304
 305
 306 //
 307 // Writers
 308 //
 309 DiskRep::Writer::Writer(uint32_t attrs)
 310         : mArch(CPU_TYPE_ANY), mAttributes(attrs)
 311 {
 312 }
 313
 314 DiskRep::Writer::~Writer()
 315 { /* virtual */ }
 316
 317 uint32_t DiskRep::Writer::attributes() const
 318 { return mAttributes; }
 319
 320 void DiskRep::Writer::flush()
 321 { /* do nothing */ }
 322
 323 void DiskRep::Writer::remove()
 324 {
 325         MacOSError::throwMe(errSecCSNotSupported);
 326 }
 327
 328
 329 } // end namespace CodeSigning
 330 } // end namespace Security