OSX/libsecurity_codesigning/lib/requirement.cpp

   1 /*
   2  * Copyright (c) 2006-2012 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 // requirement - Code Requirement Blob description
  26 //
  27 #include "requirement.h"
  28 #include "reqinterp.h"
  29 #include "codesigning_dtrace.h"
  30 #include <security_utilities/errors.h>
  31 #include <security_utilities/unix++.h>
  32 #include <security_utilities/logging.h>
  33 #include <security_utilities/cfutilities.h>
  34 #include <security_utilities/hashing.h>
  35
  36 #ifdef DEBUGDUMP
  37 #include <security_codesigning/reqdumper.h>
  38 #endif
  39
  40 namespace Security {
  41 namespace CodeSigning {
  42
  43
  44 //
  45 // Canonical names for requirement types
  46 //
  47 const char *const Requirement::typeNames[] = {
  48         "invalid",
  49         "host",
  50         "guest",
  51         "designated",
  52         "library",
  53         "plugin",
  54 };
  55
  56
  57 //
  58 // validate a requirement against a code context
  59 //
  60 void Requirement::validate(const Requirement::Context &ctx, OSStatus failure /* = errSecCSReqFailed */) const
  61 {
  62         if (!this->validates(ctx, failure))
  63                 MacOSError::throwMe(failure);
  64 }
  65
  66 bool Requirement::validates(const Requirement::Context &ctx, OSStatus failure /* = errSecCSReqFailed */) const
  67 {
  68         CODESIGN_EVAL_REQINT_START((void*)this, (int)this->length());
  69         switch (kind()) {
  70         case exprForm:
  71                 if (Requirement::Interpreter(this, &ctx).evaluate()) {
  72                         CODESIGN_EVAL_REQINT_END(this, 0);
  73                         return true;
  74                 } else {
  75                         CODESIGN_EVAL_REQINT_END(this, failure);
  76                         return false;
  77                 }
  78         default:
  79                 CODESIGN_EVAL_REQINT_END(this, errSecCSReqUnsupported);
  80                 MacOSError::throwMe(errSecCSReqUnsupported);
  81         }
  82 }
  83
  84
  85 //
  86 // Retrieve one certificate from the cert chain.
  87 // Positive and negative indices can be used:
  88 //    [ leaf, intermed-1, ..., intermed-n, anchor ]
  89 //        0       1       ...     -2         -1
  90 // Returns NULL if unavailable for any reason.
  91 //
  92 SecCertificateRef Requirement::Context::cert(int ix) const
  93 {
  94         if (certs) {
  95                 if (ix < 0)
  96                         ix += certCount();
  97                 if (ix >= CFArrayGetCount(certs))
  98                     return NULL;
  99                 if (CFTypeRef element = CFArrayGetValueAtIndex(certs, ix))
 100                         return SecCertificateRef(element);
 101         }
 102         return NULL;
 103 }
 104
 105 unsigned int Requirement::Context::certCount() const
 106 {
 107         if (certs)
 108                 return (unsigned int)CFArrayGetCount(certs);
 109         else
 110                 return 0;
 111 }
 112
 113
 114 //
 115 // Produce the hash of a fake Apple root (only if compiled for internal testing)
 116 //
 117 #if defined(TEST_APPLE_ANCHOR)
 118
 119 const char Requirement::testAppleAnchorEnv[] = "TEST_APPLE_ANCHOR";
 120
 121 const SHA1::Digest &Requirement::testAppleAnchorHash()
 122 {
 123         static bool tried = false;
 124         static SHA1::Digest testHash;
 125         if (!tried) {
 126                 // see if we have one configured
 127                 if (const char *path = getenv(testAppleAnchorEnv))
 128                         try {
 129                                 UnixPlusPlus::FileDesc fd(path);
 130                                 char buffer[2048];              // arbitrary limit
 131                                 size_t size = fd.read(buffer, sizeof(buffer));
 132                                 SHA1 hash;
 133                                 hash(buffer, size);
 134                                 hash.finish(testHash);
 135                                 Syslog::alert("ACCEPTING TEST AUTHORITY %s FOR APPLE CODE IDENTITY", path);
 136                         } catch (...) { }
 137                 tried = true;
 138         }
 139         return testHash;                // will be zeroes (no match) if not configured
 140 }
 141
 142 #endif //TEST_APPLE_ANCHOR
 143
 144
 145 //
 146 // Debug dump support
 147 //
 148 #ifdef DEBUGDUMP
 149
 150 void Requirement::dump() const
 151 {
 152         Debug::dump("%s\n", Dumper::dump(this).c_str());
 153 }
 154
 155 #endif //DEBUGDUMP
 156
 157
 158 }       // CodeSigning
 159 }       // Security