cdsa/cdsa_utilities/acl_threshold.cpp

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, 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 // acl_threshold - Threshold-based group ACL subjects
  21 //
  22 #ifdef __MWERKS__
  23 #define _CPP_ACL_THRESHOLD
  24 #endif
  25
  26 #include <Security/acl_threshold.h>
  27 #include <algorithm>
  28
  29
  30 //
  31 // Validate a credential set against this subject.
  32 //
  33 // With STRICTCOUNTING set, we assume that every match in the threshold ACL
  34 // "consumes" one sample in the corresponding threshold sample. This will not
  35 // work as expected for subject types that may succeed without a sample (e.g. ANY)
  36 // or subject types that may multiply match against a single sample. You have been
  37 // warned.
  38 //
  39 class SublistValidationContext : public AclValidationContext {
  40 public:
  41     SublistValidationContext(const AclValidationContext &ctx, const TypedList &list)
  42     : AclValidationContext(ctx), sampleList(list) { }
  43
  44     uint32 count() const { return sampleList.length() - 1; }
  45     const TypedList &sample(uint32 n) const
  46     { return TypedList::overlay(sampleList[n+1].list()); }
  47
  48     const TypedList &sampleList;
  49 };
  50
  51 bool ThresholdAclSubject::validate(const AclValidationContext &baseCtx,
  52     const TypedList &sample) const
  53 {
  54 #ifdef STRICTCOUNTING
  55     // Pre-screen for reasonable number of subsamples.
  56     // We could more strictly require subSampleCount == elements.length();
  57     // this is more flexible in that it allows the caller to abbreviate.
  58     uint32 subSampleCount = sample.length() - 1;        // (drop type header)
  59     if (subSampleCount < minimumNeeded) // can't possibly satisfy
  60                 CssmError::throwMe(CSSM_ERRCODE_INVALID_SAMPLE_VALUE);
  61     if (subSampleCount > totalSubjects) // reject attempt at sample stuffing
  62                 CssmError::throwMe(CSSM_ERRCODE_INVALID_SAMPLE_VALUE);
  63 #endif //STRICTCOUNTING
  64
  65     // evaluate
  66     SublistValidationContext ctx(baseCtx, sample);
  67     uint32 matched = 0;
  68     for (uint32 n = 0; n < totalSubjects; n++) {
  69                 if ((matched += elements[n]->validate(ctx)) >= minimumNeeded)
  70             return true;
  71 #ifdef STRICTCOUNTING
  72         else if (matched + subSampleCount - n <= minimumNeeded)
  73             return false;       // can't get there anymore
  74 #endif //STRICTCOUNTING
  75     }
  76         return false;
  77 }
  78
  79
  80 //
  81 // Make a copy of this subject in CSSM_LIST form
  82 //
  83 CssmList ThresholdAclSubject::toList(CssmAllocator &alloc) const
  84 {
  85         TypedList result(alloc, CSSM_ACL_SUBJECT_TYPE_THRESHOLD,
  86                 new(alloc) ListElement(minimumNeeded),
  87                 new(alloc) ListElement(totalSubjects));
  88     for (uint32 n = 0; n < totalSubjects; n++)
  89                 result += new(alloc) ListElement(elements[n]->toList(alloc));
  90         return result;
  91 }
  92
  93
  94 //
  95 // Create a ThresholdAclSubject
  96 //
  97 ThresholdAclSubject *ThresholdAclSubject::Maker::make(const TypedList &list) const
  98 {
  99     // pick apart the input list
 100     if (list.length() < 4)      // head + "n" + "k" + at least one subSubject
 101         CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
 102     uint32 minimumNeeded = getWord(list[1], 1);
 103     uint32 totalSubjects = getWord(list[2], minimumNeeded);
 104     if (list.length() != 3 + totalSubjects)
 105         CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
 106
 107     // now compile the subSubjects
 108     AclSubjectVector elements(totalSubjects);
 109     const ListElement *subSubject = &list[3];
 110     for (uint32 n = 0; n < totalSubjects; n++, subSubject = subSubject->next())
 111         elements[n] = ObjectAcl::make(*subSubject);
 112         return new ThresholdAclSubject(totalSubjects, minimumNeeded, elements);
 113 }
 114
 115 ThresholdAclSubject *ThresholdAclSubject::Maker::make(Version, Reader &pub, Reader &priv) const
 116 {
 117     uint32 totalSubjects; pub(totalSubjects);
 118     uint32 minimumNeeded; pub(minimumNeeded);
 119     AclSubjectVector subSubjects(totalSubjects);
 120     for (uint32 n = 0; n < totalSubjects; n++)
 121                 subSubjects[n] = ObjectAcl::importSubject(pub, priv);
 122         return new ThresholdAclSubject(totalSubjects, minimumNeeded, subSubjects);
 123 }
 124
 125 ThresholdAclSubject::ThresholdAclSubject(uint32 n, uint32 k,
 126     const AclSubjectVector &subSubjects)
 127 : SimpleAclSubject(CSSM_ACL_SUBJECT_TYPE_THRESHOLD, CSSM_SAMPLE_TYPE_THRESHOLD),
 128   minimumNeeded(k), totalSubjects(n), elements(subSubjects)
 129 {
 130 }
 131
 132
 133 //
 134 // Export the subject to a memory blob
 135 //
 136 template <class Action>
 137 void ThresholdAclSubject::exportBlobForm(Action &pub, Action &priv)
 138 {
 139     pub(totalSubjects);
 140     pub(minimumNeeded);
 141     for (uint32 n = 0; n < totalSubjects; n++)
 142                 ObjectAcl::exportSubject(elements[n], pub, priv);
 143 }
 144
 145 void ThresholdAclSubject::exportBlob(Writer::Counter &pub, Writer::Counter &priv)
 146 { exportBlobForm(pub, priv); }
 147
 148 void ThresholdAclSubject::exportBlob(Writer &pub, Writer &priv)
 149 { exportBlobForm(pub, priv); }
 150
 151
 152 #ifdef DEBUGDUMP
 153
 154 void ThresholdAclSubject::debugDump() const
 155 {
 156         Debug::dump("Threshold(%ld of %ld)", minimumNeeded, totalSubjects);
 157         for (unsigned int n = 0; n < elements.size(); n++) {
 158                 Debug::dump(" [");
 159                 if (Version v = elements[n]->version())
 160                         Debug::dump("V=%d ", v);
 161                 elements[n]->debugDump();
 162                 Debug::dump("]");
 163         }
 164 }
 165
 166 #endif //DEBUGDUMP