lib/diskrep.h

   1 /*
   2  * Copyright (c) 2006-2007 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 // diskrep - disk representations of code
  26 //
  27 #ifndef _H_DISKREP
  28 #define _H_DISKREP
  29
  30 #include "cs.h"
  31 #include "codedirectory.h"
  32 #include "requirement.h"
  33 #include "macho++.h"            // for class Architecture
  34 #include <security_utilities/refcount.h>
  35 #include <security_utilities/superblob.h>
  36 #include <CoreFoundation/CFData.h>
  37
  38 namespace Security {
  39 namespace CodeSigning {
  40
  41
  42 //
  43 // DiskRep is an abstract interface to code somewhere located by
  44 // a file system path. It presents the ability to read and write
  45 // Code Signing-related information about such code without exposing
  46 // the details of the storage locations or formats.
  47 //
  48 class DiskRep : public RefCount {
  49 public:
  50         DiskRep();
  51         virtual ~DiskRep();
  52         virtual DiskRep *base();
  53         virtual CFDataRef component(CodeDirectory::SpecialSlot slot) = 0; // fetch component
  54         virtual std::string mainExecutablePath() = 0;                   // path to main executable
  55         virtual CFURLRef canonicalPath() = 0;                                   // path to whole code
  56         virtual std::string recommendedIdentifier() = 0;                // default identifier
  57         virtual std::string resourcesRootPath();                                // resource directory if any
  58         virtual CFDictionaryRef defaultResourceRules();                 // default resource rules
  59         virtual const Requirements *defaultRequirements(const Architecture *arch); // default internal requirements
  60         virtual Universal *mainExecutableImage();                               // binary if Mach-O/Universal
  61         virtual size_t pageSize();                                                              // default main executable page size
  62         virtual size_t signingBase();                                                   // start offset of signed area in main executable
  63         virtual size_t signingLimit() = 0;                                              // size of signed area in main executable
  64         virtual std::string format() = 0;                                               // human-readable type string
  65         virtual CFArrayRef modifiedFiles();                                             // list of files modified by signing
  66         virtual UnixPlusPlus::FileDesc &fd() = 0;                               // a cached fd for main executable file
  67         virtual void flush();                                                                   // flush caches (refetch as needed)
  68
  69         bool mainExecutableIsMachO() { return mainExecutableImage() != NULL; }
  70
  71         // shorthands
  72         CFDataRef codeDirectory()       { return component(cdCodeDirectorySlot); }
  73         CFDataRef signature()           { return component(cdSignatureSlot); }
  74
  75 public:
  76         class Writer;
  77         virtual Writer *writer();
  78
  79 public:
  80         static DiskRep *bestGuess(const char *path);                    // canonical heuristic, any path
  81         static DiskRep *bestFileGuess(const char *path);                // canonical heuristic, single file only
  82
  83         static DiskRep *bestGuess(const std::string &path)              { return bestGuess(path.c_str()); }
  84         static DiskRep *bestFileGuess(const std::string &path)  { return bestFileGuess(path.c_str()); }
  85
  86
  87 public:
  88         static const size_t segmentedPageSize = 4096;   // default page size for system-paged signatures
  89         static const size_t monolithicPageSize = 0;             // default page size for non-Mach-O executables
  90 };
  91
  92
  93 //
  94 // Write-access objects.
  95 // At this layer they are quite abstract, carrying just the functionality needed
  96 // for the signing machinery to place data wherever it should go. Each DiskRep subclass
  97 // that supports writing signing data to a place inside the code needs to implement
  98 // a subclass of Writer and return an instance in the DiskRep::writer() method when asked.
  99 //
 100 class DiskRep::Writer : public RefCount {
 101 public:
 102         Writer(uint32_t attrs = 0);
 103         virtual ~Writer();
 104         virtual void component(CodeDirectory::SpecialSlot slot, CFDataRef data) = 0;
 105         virtual uint32_t attributes() const;
 106         virtual void flush();
 107
 108         bool attribute(uint32_t attr) const             { return mAttributes & attr; }
 109
 110         void signature(CFDataRef data)                  { component(cdSignatureSlot, data); }
 111         void codeDirectory(const CodeDirectory *cd)
 112                 { component(cdCodeDirectorySlot, CFTempData(cd->data(), cd->length())); }
 113
 114 private:
 115         Architecture mArch;
 116         uint32_t mAttributes;
 117 };
 118
 119 //
 120 // Writer attributes. Defaults should be off-bits.
 121 //
 122 enum {
 123         writerLastResort = 0x0001,                      // prefers not to store attributes itself
 124         writerNoGlobal = 0x0002,                        // has only per-architecture storage
 125 };
 126
 127
 128 } // end namespace CodeSigning
 129 } // end namespace Security
 130
 131 #endif // !_H_DISKREP