OSX/libsecurity_codesigning/lib/diskrep.h

   1 /*
   2  * Copyright (c) 2006-2007,2011-2012,2014 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 // 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 "cdbuilder.h"
  33 #include "requirement.h"
  34 #include "resources.h"
  35 #include <security_utilities/macho++.h>         // for class Architecture
  36 #include <security_utilities/refcount.h>
  37 #include <security_utilities/superblob.h>
  38 #include <CoreFoundation/CFData.h>
  39
  40 namespace Security {
  41 namespace CodeSigning {
  42
  43 class ResourceBuilder;
  44
  45
  46 //
  47 // DiskRep is an abstract interface to code somewhere located by
  48 // a file system path. It presents the ability to read and write
  49 // Code Signing-related information about such code without exposing
  50 // the details of the storage locations or formats.
  51 //
  52 class DiskRep : public RefCount {
  53 public:
  54         class SigningContext;
  55
  56         typedef std::set<OSStatus> ToleratedErrors;
  57
  58 public:
  59         DiskRep();
  60         virtual ~DiskRep();
  61         virtual DiskRep *base();
  62         virtual CFDataRef component(CodeDirectory::SpecialSlot slot) = 0; // fetch component
  63         virtual CFDataRef identification() = 0;                                 // binary lookup identifier
  64         virtual std::string mainExecutablePath() = 0;                   // path to main executable
  65         virtual CFURLRef copyCanonicalPath() = 0;                                       // path to whole code
  66         virtual std::string resourcesRootPath();                                // resource directory if any [none]
  67         virtual void adjustResources(ResourceBuilder &builder); // adjust resource rule set [no change]
  68         virtual Universal *mainExecutableImage();                               // Mach-O image if Mach-O based [null]
  69         virtual size_t signingBase();                                                   // start offset of signed area in main executable [zero]
  70         virtual size_t signingLimit() = 0;                                              // size of signed area in main executable
  71         virtual std::string format() = 0;                                               // human-readable type string
  72         virtual CFArrayRef modifiedFiles();                                             // list of files modified by signing [main execcutable only]
  73         virtual UnixPlusPlus::FileDesc &fd() = 0;                               // a cached file descriptor for main executable file
  74         virtual void flush();                                                                   // flush caches (refetch as needed)
  75
  76         // default values for signing operations
  77         virtual std::string recommendedIdentifier(const SigningContext &ctx) = 0; // default identifier
  78         virtual CFDictionaryRef defaultResourceRules(const SigningContext &ctx); // default resource rules [none]
  79         virtual const Requirements *defaultRequirements(const Architecture *arch,
  80                 const SigningContext &ctx);                                                     // default internal requirements [none]
  81         virtual size_t pageSize(const SigningContext &ctx);             // default main executable page size [infinite, i.e. no paging]
  82
  83         virtual void strictValidate(const CodeDirectory* cd, const ToleratedErrors& tolerated); // perform strict validation
  84         virtual CFArrayRef allowedResourceOmissions();                  // allowed (default) resource omission rules
  85
  86         bool mainExecutableIsMachO() { return mainExecutableImage() != NULL; }
  87
  88         // shorthands
  89         CFDataRef codeDirectory()       { return component(cdCodeDirectorySlot); }
  90         CFDataRef signature()           { return component(cdSignatureSlot); }
  91
  92 public:
  93         class Writer;
  94         virtual Writer *writer();                                                               // Writer factory
  95
  96 public:
  97         // optional information that might be used to create a suitable DiskRep. All optional
  98         struct Context {
  99                 Context() : arch(Architecture::none), version(NULL), offset(0), fileOnly(false), inMemory(NULL), size(0) { }
 100                 Architecture arch;                      // explicit architecture (choose amongst universal variants)
 101                 const char *version;            // bundle version (string)
 102                 off_t offset;                           // explicit file offset
 103                 bool fileOnly;                          // only consider single-file representations (no bundles etc.)
 104                 const void *inMemory;           // consider using in-memory copy at this address
 105                 size_t size;                            // size of this mach-o slice
 106         };
 107
 108         static DiskRep *bestGuess(const char *path, const Context *ctx = NULL); // canonical heuristic, any path
 109         static DiskRep *bestFileGuess(const char *path, const Context *ctx = NULL); // ctx (if any) + fileOnly
 110         static DiskRep *bestGuess(const char *path, size_t archOffset); // Mach-O at given file offset only
 111
 112         // versions using std::string paths (merely a convenience)
 113         static DiskRep *bestGuess(const std::string &path, const Context *ctx = NULL)
 114                 { return bestGuess(path.c_str(), ctx); }
 115         static DiskRep *bestGuess(const std::string &path, size_t archOffset) { return bestGuess(path.c_str(), archOffset); }
 116         static DiskRep *bestFileGuess(const std::string &path, const Context *ctx = NULL) { return bestFileGuess(path.c_str(), ctx); }
 117
 118 public:
 119         // see DiskRep::Writer docs for why this is here
 120         class SigningContext {
 121         protected:
 122                 SigningContext() { }
 123
 124         public:
 125                 virtual std::string sdkPath(const std::string &path) const = 0;
 126                 virtual bool isAdhoc() const = 0;
 127                 virtual SecCSFlags signingFlags() const = 0;
 128         };
 129
 130 protected:
 131         // canonically derive a suggested signing identifier from some string
 132         static std::string canonicalIdentifier(const std::string &name);
 133
 134 public:
 135         static const size_t segmentedPageSize = 4096;   // default page size for system-paged signatures
 136         static const size_t monolithicPageSize = 0;             // default page size for non-Mach-O executables
 137 };
 138
 139
 140 //
 141 // Write-access objects.
 142 // At this layer they are quite abstract, carrying just the functionality needed
 143 // for the signing machinery to place data wherever it should go. Each DiskRep subclass
 144 // that supports writing signing data to a place inside the code needs to implement
 145 // a subclass of Writer and return an instance in the DiskRep::writer() method when asked.
 146 //
 147 // The Writer class is subclassed interestingly by the Mach-O multi-architecture signing code,
 148 // which is handled as a special case. This means that not all Writer subclass objects were made
 149 // by DiskRep::writer, and it is unwise to assume so.
 150 //
 151 // Note that the methods that provide defaults for signing operations are in DiskRep rather
 152 // than here. That's because writers abstract data *sending*, and are virtual on management
 153 // of stored data, while DiskRep is virtual on the existing code object, which is where
 154 // we get our defaults from.
 155 //
 156 class DiskRep::Writer : public RefCount {
 157 public:
 158         Writer(uint32_t attrs = 0);
 159         virtual ~Writer();
 160         virtual void component(CodeDirectory::SpecialSlot slot, CFDataRef data) = 0;
 161         virtual uint32_t attributes() const;
 162         virtual void addDiscretionary(CodeDirectory::Builder &builder);
 163         virtual void remove();
 164         virtual void flush();
 165
 166         bool attribute(uint32_t attr) const             { return mAttributes & attr; }
 167
 168         void signature(CFDataRef data)                  { component(cdSignatureSlot, data); }
 169         void codeDirectory(const CodeDirectory *cd)
 170                 { component(cdCodeDirectorySlot, CFTempData(cd->data(), cd->length())); }
 171
 172 private:
 173         Architecture mArch;
 174         uint32_t mAttributes;
 175 };
 176
 177 //
 178 // Writer attributes. Defaults should be off-bits.
 179 //
 180 enum {
 181         writerLastResort = 0x0001,                      // prefers not to store attributes itself
 182         writerNoGlobal = 0x0002,                        // has only per-architecture storage
 183 };
 184
 185
 186 //
 187 // A prefix DiskRep that filters (only) signature-dependent behavior and passes
 188 // all code-dependent behavior off to an underlying (different) DiskRep.
 189 // FilterRep subclasses are typically "stacked" on top of their base DiskRep, and
 190 // then used in their place.
 191 //
 192 class FilterRep : public DiskRep {
 193 public:
 194         FilterRep(DiskRep *orig) : mOriginal(orig) { }
 195
 196         DiskRep *base()                                                 { return mOriginal; }
 197
 198         // things that look at signature components are filtered
 199         CFDataRef component(CodeDirectory::SpecialSlot slot) = 0;
 200
 201         // the rest of the virtual behavior devolves on the original DiskRep
 202         CFDataRef identification()                              { return mOriginal->identification(); }
 203         std::string mainExecutablePath()                { return mOriginal->mainExecutablePath(); }
 204         CFURLRef copyCanonicalPath()                    { return mOriginal->copyCanonicalPath(); }
 205         std::string resourcesRootPath()                 { return mOriginal->resourcesRootPath(); }
 206         void adjustResources(ResourceBuilder &builder) { return mOriginal->adjustResources(builder); }
 207         Universal *mainExecutableImage()                { return mOriginal->mainExecutableImage(); }
 208         size_t signingBase()                                    { return mOriginal->signingBase(); }
 209         size_t signingLimit()                                   { return mOriginal->signingLimit(); }
 210         std::string format()                                    { return mOriginal->format(); }
 211         CFArrayRef modifiedFiles()                              { return mOriginal->modifiedFiles(); }
 212         UnixPlusPlus::FileDesc &fd()                    { return mOriginal->fd(); }
 213         void flush()                                                    { return mOriginal->flush(); }
 214
 215         std::string recommendedIdentifier(const SigningContext &ctx)
 216                 { return mOriginal->recommendedIdentifier(ctx); }
 217         CFDictionaryRef defaultResourceRules(const SigningContext &ctx)
 218                 { return mOriginal->defaultResourceRules(ctx); }
 219         const Requirements *defaultRequirements(const Architecture *arch, const SigningContext &ctx)
 220                 { return mOriginal->defaultRequirements(arch, ctx); }
 221         size_t pageSize(const SigningContext &ctx) { return mOriginal->pageSize(ctx); }
 222
 223         void strictValidate(const CodeDirectory* cd, const ToleratedErrors& tolerated) { mOriginal->strictValidate(cd, tolerated); }
 224         CFArrayRef allowedResourceOmissions() { return mOriginal->allowedResourceOmissions(); }
 225
 226 private:
 227         RefPointer<DiskRep> mOriginal;                  // underlying representation
 228 };
 229
 230
 231 } // end namespace CodeSigning
 232 } // end namespace Security
 233
 234 #endif // !_H_DISKREP