keychain/SecureObjectSync/SOSRingBackup.m

   1 //
   2 //  SOSRingBasic.c
   3 //  sec
   4 //
   5 //  Created by Richard Murphy on 3/3/15.
   6 //
   7 //
   8
   9 #include "SOSRingBackup.h"
  10
  11 #include <AssertMacros.h>
  12
  13 #include "keychain/SecureObjectSync/SOSInternal.h"
  14 #include "keychain/SecureObjectSync/SOSPeerInfoInternal.h"
  15 #include "keychain/SecureObjectSync/SOSPeerInfoCollections.h"
  16 #include "keychain/SecureObjectSync/SOSCircle.h"
  17 #include <Security/SecureObjectSync/SOSViews.h>
  18 #include <Security/SecFramework.h>
  19
  20 #include <Security/SecKey.h>
  21 #include <Security/SecKeyPriv.h>
  22 #include <CoreFoundation/CoreFoundation.h>
  23
  24 #include <utilities/SecCFWrappers.h>
  25
  26 #include <stdlib.h>
  27 #include <assert.h>
  28
  29 #include "SOSRingUtils.h"
  30 #include "SOSRingTypes.h"
  31 #include "SOSRingBasic.h"
  32
  33 // MARK: Backup Ring Ops
  34
  35 static SOSRingRef SOSRingCreate_Backup(CFStringRef name, CFStringRef myPeerID, CFErrorRef *error) {
  36     return SOSRingCreate_ForType(name, kSOSRingBackup, myPeerID, error);
  37 }
  38
  39
  40 // Make sure all the peers in the ring have access to the ring views
  41 static bool SOSBackupRingPeersInViews(CFSetRef peers, SOSRingRef ring) {
  42     CFSetRef ringViews = SOSBackupRingGetViews(ring, NULL);
  43     if(!ringViews) return false;
  44     __block bool retval = true;
  45     SOSRingForEachPeerID(ring, ^(CFStringRef peerID) {
  46         SOSPeerInfoRef peerInfo = SOSPeerInfoSetFindByID(peers, peerID);
  47         if(peerInfo) {
  48             CFSetForEach(ringViews, ^(const void *value) {
  49                 if(!SOSPeerInfoIsViewPermitted(peerInfo, (CFStringRef) value)) retval = false;
  50             });
  51         } else {
  52             retval = false;
  53         }
  54     });
  55     return retval;
  56 }
  57
  58 // Make sure that the ring includes me if I'm enabled for its view.
  59 static SOSConcordanceStatus SOSBackupRingEvaluateMyInclusion(SOSRingRef ring, SOSFullPeerInfoRef me) {
  60     bool shouldBeInRing = false;
  61     bool amInThisRing = false;
  62
  63     if (me) {
  64         SOSPeerInfoRef pi = SOSFullPeerInfoGetPeerInfo(me);
  65         CFStringRef peerID = SOSPeerInfoGetPeerID(pi);
  66         CFSetRef ringViews = SOSRingGetBackupViewset_Internal(ring);
  67         CFSetRef piViews = SOSPeerInfoGetPermittedViews(pi);
  68         shouldBeInRing = CFSetIsSubset(ringViews, piViews);
  69         amInThisRing = SOSRingHasPeerWithID(ring, peerID, NULL);
  70     }
  71
  72     if(shouldBeInRing && !amInThisRing) return kSOSConcordanceMissingMe;
  73     if(!shouldBeInRing && amInThisRing) return kSOSConcordanceImNotWorthy;
  74     return kSOSConcordanceTrusted;
  75 }
  76
  77 static SOSConcordanceStatus SOSRingPeerKeyConcordanceTrust_Backup(SOSFullPeerInfoRef me, CFSetRef peers, SOSRingRef knownRing, SOSRingRef proposedRing,
  78                                                     __unused SecKeyRef knownPubkey, SecKeyRef userPubkey,
  79                                                     CFStringRef excludePeerID, CFErrorRef *error) {
  80     if(userPubkey == NULL) {
  81         SOSCreateError(kSOSErrorPublicKeyAbsent, CFSTR("Concordance with no public key - need to validate application"), NULL, error);
  82         return kSOSConcordanceNoUserKey;
  83     }
  84
  85     if(SOSRingIsOlderGeneration(proposedRing, knownRing)) {
  86         SOSCreateError(kSOSErrorReplay, CFSTR("Bad generation"), NULL, error);
  87         return kSOSConcordanceGenOld;
  88     }
  89
  90
  91     if (SOSRingIsEmpty_Internal(proposedRing)) {
  92         return kSOSConcordanceTrusted;
  93     }
  94
  95     SOSConcordanceStatus localstatus = SOSBackupRingEvaluateMyInclusion(proposedRing, me);
  96     if(localstatus == kSOSConcordanceMissingMe) {
  97         SOSCreateError(kSOSErrorReplay, CFSTR("Improper exclusion of this peer"), NULL, error);
  98         return localstatus;
  99     }
 100
 101     if(localstatus == kSOSConcordanceImNotWorthy) {
 102         SOSCreateError(kSOSErrorReplay, CFSTR("Improper inclusion of this peer"), NULL, error);
 103         return localstatus;
 104     }
 105
 106     if(!SOSBackupRingPeersInViews(peers, proposedRing)) {
 107         return kSOSConcordanceInvalidMembership;
 108     }
 109
 110     return GetSignersStatus_Transitive(peers, knownRing, proposedRing, userPubkey, excludePeerID, error);
 111 }
 112
 113 bool SOSBackupRingSetViews(SOSRingRef ring, SOSFullPeerInfoRef requestor, CFSetRef viewSet, CFErrorRef *error) {
 114     CFStringRef myPeerID = SOSPeerInfoGetPeerID(SOSFullPeerInfoGetPeerInfo(requestor));
 115     SecKeyRef priv = SOSFullPeerInfoCopyDeviceKey(requestor, error);
 116     bool retval = priv && myPeerID &&
 117     SOSRingSetLastModifier(ring, myPeerID) &&
 118     SOSRingSetBackupViewset_Internal(ring, viewSet) &&
 119     SOSRingGenerationSign_Internal(ring, priv, error);
 120     CFReleaseNull(priv);
 121     return retval;
 122 }
 123
 124 CFSetRef SOSBackupRingGetViews(SOSRingRef ring, CFErrorRef *error) {
 125     return SOSRingGetBackupViewset_Internal(ring);
 126 }
 127
 128 ringFuncStruct backup = {
 129     "Backup",
 130     1,
 131     SOSRingCreate_Backup,
 132     SOSRingResetToEmpty_Basic,
 133     SOSRingResetToOffering_Basic,
 134     SOSRingDeviceIsInRing_Basic,
 135     SOSRingApply_Basic,
 136     SOSRingWithdraw_Basic,
 137     SOSRingGenerationSign_Basic,
 138     SOSRingConcordanceSign_Basic,
 139     SOSRingPeerKeyConcordanceTrust_Backup,
 140     NULL,
 141     NULL,
 142     SOSRingSetPayload_Basic,
 143     SOSRingGetPayload_Basic,
 144 };