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 #include <Security/endian.h>
  29
  30
  31 //
  32 // Validate a credential set against this subject.
  33 //
  34 // With STRICTCOUNTING set, we assume that every match in the threshold ACL
  35 // "consumes" one sample in the corresponding threshold sample. This will not
  36 // work as expected for subject types that may succeed without a sample (e.g. ANY)
  37 // or subject types that may multiply match against a single sample. You have been
  38 // warned.
  39 //
  40 class SublistValidationContext : public AclValidationContext {
  41 public:
  42     SublistValidationContext(const AclValidationContext &ctx, const TypedList &list)
  43     : AclValidationContext(ctx), sampleList(list) { }
  44
  45     uint32 count() const { return sampleList.length() - 1; }
  46     const TypedList &sample(uint32 n) const
  47     { return TypedList::overlay(sampleList[n+1].list()); }
  48
  49     const TypedList &sampleList;
  50 };
  51
  52 bool ThresholdAclSubject::validate(const AclValidationContext &baseCtx,
  53     const TypedList &sample) const
  54 {
  55 #ifdef STRICTCOUNTING
  56     // Pre-screen for reasonable number of subsamples.
  57     // We could more strictly require subSampleCount == elements.length();
  58     // this is more flexible in that it allows the caller to abbreviate.
  59     uint32 subSampleCount = sample.length() - 1;        // (drop type header)
  60     if (subSampleCount < minimumNeeded) // can't possibly satisfy
  61                 CssmError::throwMe(CSSM_ERRCODE_INVALID_SAMPLE_VALUE);
  62     if (subSampleCount > totalSubjects) // reject attempt at sample stuffing
  63                 CssmError::throwMe(CSSM_ERRCODE_INVALID_SAMPLE_VALUE);
  64 #endif //STRICTCOUNTING
  65
  66     // evaluate
  67     SublistValidationContext ctx(baseCtx, sample);
  68     uint32 matched = 0;
  69     for (uint32 n = 0; n < totalSubjects; n++) {
  70                 if ((matched += elements[n]->validate(ctx)) >= minimumNeeded)
  71             return true;
  72 #ifdef STRICTCOUNTING
  73         else if (matched + subSampleCount - n <= minimumNeeded)
  74             return false;       // can't get there anymore
  75 #endif //STRICTCOUNTING
  76     }
  77         return false;
  78 }
  79
  80
  81 //
  82 // Make a copy of this subject in CSSM_LIST form
  83 //
  84 CssmList ThresholdAclSubject::toList(CssmAllocator &alloc) const
  85 {
  86         TypedList result(alloc, CSSM_ACL_SUBJECT_TYPE_THRESHOLD,
  87                 new(alloc) ListElement(minimumNeeded),
  88                 new(alloc) ListElement(totalSubjects));
  89     for (uint32 n = 0; n < totalSubjects; n++)
  90                 result += new(alloc) ListElement(elements[n]->toList(alloc));
  91         return result;
  92 }
  93
  94
  95 //
  96 // Create a ThresholdAclSubject
  97 //
  98 ThresholdAclSubject *ThresholdAclSubject::Maker::make(const TypedList &list) const
  99 {
 100     // pick apart the input list
 101     if (list.length() < 4)      // head + "n" + "k" + at least one subSubject
 102         CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
 103     uint32 minimumNeeded = getWord(list[1], 1);
 104     uint32 totalSubjects = getWord(list[2], minimumNeeded);
 105     if (list.length() != 3 + totalSubjects)
 106         CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
 107
 108     // now compile the subSubjects
 109     AclSubjectVector elements(totalSubjects);
 110     const ListElement *subSubject = &list[3];
 111     for (uint32 n = 0; n < totalSubjects; n++, subSubject = subSubject->next())
 112         elements[n] = ObjectAcl::make(subSubject->typedList());
 113         return new ThresholdAclSubject(totalSubjects, minimumNeeded, elements);
 114 }
 115
 116 ThresholdAclSubject *ThresholdAclSubject::Maker::make(Version, Reader &pub, Reader &priv) const
 117 {
 118     Endian<uint32> totalSubjects; pub(totalSubjects);
 119     Endian<uint32> minimumNeeded; pub(minimumNeeded);
 120     AclSubjectVector subSubjects(totalSubjects);
 121     for (uint32 n = 0; n < totalSubjects; n++)
 122                 subSubjects[n] = ObjectAcl::importSubject(pub, priv);
 123         return new ThresholdAclSubject(totalSubjects, minimumNeeded, subSubjects);
 124 }
 125
 126 ThresholdAclSubject::ThresholdAclSubject(uint32 n, uint32 k,
 127     const AclSubjectVector &subSubjects)
 128 : SimpleAclSubject(CSSM_ACL_SUBJECT_TYPE_THRESHOLD, CSSM_SAMPLE_TYPE_THRESHOLD),
 129   minimumNeeded(k), totalSubjects(n), elements(subSubjects)
 130 {
 131 }
 132
 133
 134 //
 135 // Export the subject to a memory blob
 136 //
 137 template <class Action>
 138 void ThresholdAclSubject::exportBlobForm(Action &pub, Action &priv)
 139 {
 140     pub(h2n(totalSubjects));
 141     pub(h2n(minimumNeeded));
 142     for (uint32 n = 0; n < totalSubjects; n++)
 143                 ObjectAcl::exportSubject(elements[n], pub, priv);
 144 }
 145
 146 void ThresholdAclSubject::exportBlob(Writer::Counter &pub, Writer::Counter &priv)
 147 { exportBlobForm(pub, priv); }
 148
 149 void ThresholdAclSubject::exportBlob(Writer &pub, Writer &priv)
 150 { exportBlobForm(pub, priv); }
 151
 152
 153 #ifdef DEBUGDUMP
 154
 155 void ThresholdAclSubject::debugDump() const
 156 {
 157         Debug::dump("Threshold(%ld of %ld)", minimumNeeded, totalSubjects);
 158         for (unsigned int n = 0; n < elements.size(); n++) {
 159                 Debug::dump(" [");
 160                 if (Version v = elements[n]->version())
 161                         Debug::dump("V=%d ", v);
 162                 elements[n]->debugDump();
 163                 Debug::dump("]");
 164         }
 165 }
 166
 167 #endif //DEBUGDUMP