OSX/libsecurity_cdsa_utilities/lib/osxverifier.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2011,2013-2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // osxsigner - MacOS X's standard code signing algorithm.
  21 //
  22 #include <security_cdsa_utilities/osxverifier.h>
  23 #include <security_utilities/unix++.h>
  24 #include <security_utilities/hashing.h>
  25 #include <security_utilities/memutils.h>
  26 #include <security_utilities/debugging.h>
  27 #include <security_codesigning/requirement.h>
  28 #include <security_codesigning/reqdumper.h>             // debug only
  29
  30
  31 using namespace CodeSigning;
  32
  33
  34 namespace Security {
  35
  36
  37 //
  38 // Create a Verifier from a code object.
  39 //
  40 // This does not add any auxiliary information blobs. You can do that
  41 // by calling add() after construction, of course.
  42 //
  43 OSXVerifier::OSXVerifier(OSXCode *code)
  44 {
  45         mPath = code->canonicalPath();
  46         secdebug("codesign", "building verifier for %s", mPath.c_str());
  47
  48         // build new-style verifier
  49         CFRef<SecStaticCodeRef> staticCode = code->codeRef();
  50         switch (OSStatus rc = SecCodeCopyDesignatedRequirement(staticCode,
  51                         kSecCSDefaultFlags, &mRequirement.aref())) {
  52         case errSecSuccess:
  53                 secdebug("codesign", "  is signed; canonical requirement loaded");
  54                 break;
  55         case errSecCSUnsigned:
  56                 secdebug("codesign", "  is unsigned; no requirement");
  57                 break;
  58         default:
  59                 MacOSError::throwMe(rc);
  60         }
  61
  62         // build old-style verifier
  63         makeLegacyHash(code, mLegacyHash);
  64         secdebug("codesign", "  hash generated");
  65 }
  66
  67
  68 //
  69 // Create a Verifier from hash, path, and requirement.
  70 // Again, this has no auxiliary data when constructed.
  71 //
  72 OSXVerifier::OSXVerifier(const SHA1::Byte *hash, const std::string &path)
  73         : mPath(path)
  74 {
  75         secdebug("codesign", "building verifier from hash %p and path=%s", hash, path.c_str());
  76         if (hash)
  77                 memcpy(mLegacyHash, hash, sizeof(mLegacyHash));
  78         else
  79                 memset(mLegacyHash, 0, sizeof(mLegacyHash));
  80 }
  81
  82
  83 OSXVerifier::~OSXVerifier()
  84 {
  85         secdebug("codesign", "%p verifier destroyed", this);
  86 }
  87
  88
  89 //
  90 // Add an auxiliary comment blob.
  91 // Note that we only allow one auxiliary blob for each magic number.
  92 //
  93 void OSXVerifier::add(const BlobCore *blob)
  94 {
  95         if (blob->is<Requirement>()) {
  96 #if defined(NDEBUG)
  97                 secdebug("codesign", "%p verifier adds requirement", this);
  98 #else
  99                 secdebug("codesign", "%p verifier adds requirement %s", this,
 100                         Dumper::dump(Requirement::specific(blob), true).c_str());
 101 #endif //NDEBUG
 102                 MacOSError::check(SecRequirementCreateWithData(CFTempData(*blob),
 103                         kSecCSDefaultFlags, &mRequirement.aref()));
 104         } else {
 105                 secdebug("codesign", "%p verifier adds blob (0x%x,%zd)",
 106                         this, blob->magic(), blob->length());
 107                 BlobCore * &slot = mAuxiliary[blob->magic()];
 108                 if (slot)
 109                         ::free(slot);
 110                 slot = blob->clone();
 111         }
 112 }
 113
 114
 115 //
 116 // Find a comment blob, by magic number
 117 //
 118 const BlobCore *OSXVerifier::find(BlobCore::Magic magic)
 119 {
 120         AuxMap::const_iterator it = mAuxiliary.find(magic);
 121         return (it == mAuxiliary.end()) ? NULL : it->second;
 122 }
 123
 124
 125 void OSXVerifier::makeLegacyHash(OSXCode *code, SHA1::Digest digest)
 126 {
 127         secdebug("codesign", "calculating legacy hash for %s", code->canonicalPath().c_str());
 128         UnixPlusPlus::AutoFileDesc fd(code->executablePath(), O_RDONLY);
 129         char buffer[legacyHashLimit];
 130         size_t size = fd.read(buffer, legacyHashLimit);
 131         SHA1 hash;
 132         hash(buffer, size);
 133         hash.finish(digest);
 134 }
 135
 136
 137 //
 138 // The AuxMap helper class provides a map-to-Blob-pointers with automatic memory management.
 139 //
 140 OSXVerifier::AuxMap::AuxMap(const OSXVerifier::AuxMap &src)
 141 {
 142         for (const_iterator it = src.begin(); it != src.end(); it++)
 143                 this->insert(*it);
 144 }
 145
 146 OSXVerifier::AuxMap::~AuxMap()
 147 {
 148         for (const_iterator it = this->begin(); it != this->end(); ++it)
 149                 ::free(it->second);
 150 }
 151
 152
 153 #if DEBUGDUMP
 154
 155 void OSXVerifier::dump() const
 156 {
 157         static const SHA1::Digest nullDigest = { 0 };
 158         if (!memcmp(mLegacyHash, nullDigest, sizeof(mLegacyHash))) {
 159                 Debug::dump("(no hash)");
 160         } else {
 161                 Debug::dump("oldHash=");
 162                 Debug::dumpData(mLegacyHash, sizeof(mLegacyHash));
 163         }
 164         if (mRequirement) {
 165                 CFRef<CFDataRef> reqData;
 166                 if (!SecRequirementCopyData(mRequirement, 0, &reqData.aref())) {
 167                         Debug::dump(" Requirement =>");
 168                         ((const Requirement *)CFDataGetBytePtr(reqData))->dump();
 169                 }
 170         } else {
 171                 Debug::dump(" NO REQ");
 172         }
 173 }
 174
 175 #endif //DEBUGDUMP
 176
 177 } // end namespace Security