keychain/SecureObjectSync/SOSRingConcordanceTrust.c

   1 //
   2 //  SOSRingConcordanceTrust.c
   3 //  sec
   4 //
   5 //  Created by Richard Murphy on 3/15/15.
   6 //
   7 //
   8
   9 #include <AssertMacros.h>
  10
  11 #include "keychain/SecureObjectSync/SOSInternal.h"
  12 #include "keychain/SecureObjectSync/SOSPeer.h"
  13 #include "keychain/SecureObjectSync/SOSPeerInfoInternal.h"
  14 #include "keychain/SecureObjectSync/SOSPeerInfoCollections.h"
  15 #include "keychain/SecureObjectSync/SOSCircle.h"
  16 #include <Security/SecFramework.h>
  17
  18 #include <Security/SecKey.h>
  19 #include <Security/SecKeyPriv.h>
  20 #include <CoreFoundation/CoreFoundation.h>
  21
  22 #include <utilities/SecCFWrappers.h>
  23
  24 //#include "ckdUtilities.h"
  25
  26 #include <corecrypto/ccder.h>
  27 #include <corecrypto/ccdigest.h>
  28 #include <corecrypto/ccsha2.h>
  29
  30
  31 #include <utilities/der_plist.h>
  32 #include <utilities/der_plist_internal.h>
  33 #include <corecrypto/ccder.h>
  34 #include <utilities/der_date.h>
  35
  36 #include <stdlib.h>
  37 #include <assert.h>
  38
  39 #include "SOSRing.h"
  40 #include "SOSRingUtils.h"
  41
  42 static inline CFDictionaryRef SOSPeerInfoDictionaryCreate(CFSetRef peers) {
  43     size_t n = CFSetGetCount(peers);
  44     SOSPeerInfoRef  peerInfos[n];
  45     CFStringRef     peerIDs[n];
  46     CFSetGetValues(peers, (const void **) peerInfos);
  47     for(size_t i = 0; i < n; i++) peerIDs[i] = SOSPeerInfoGetPeerID(peerInfos[i]);
  48     return CFDictionaryCreate(NULL, (const void **)peerIDs, (const void **)peerInfos, n, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
  49 }
  50
  51 static inline SOSConcordanceStatus CheckPeerStatus(CFStringRef peerID, SOSPeerInfoRef peer, SOSRingRef ring, SecKeyRef userPub, CFErrorRef *error) {
  52     SOSConcordanceStatus result = kSOSConcordanceNoPeer;
  53     SecKeyRef pubKey = NULL;
  54
  55     require_action_quiet(peer, exit, result = kSOSConcordanceNoPeer);
  56     pubKey = SOSPeerInfoCopyPubKey(peer, error);
  57     require_quiet(pubKey, exit);
  58     require_action_quiet(SOSRingHasPeerID(ring, peerID), exit, result = kSOSConcordanceNoPeer);
  59     require_action_quiet(SOSPeerInfoApplicationVerify(peer, userPub, NULL), exit, result = kSOSConcordanceNoPeer);
  60     require_action_quiet(SOSRingVerifySignatureExists(ring, pubKey, error), exit, result = kSOSConcordanceNoPeerSig);
  61     require_action_quiet(SOSRingVerify(ring, pubKey, error), exit, result = kSOSConcordanceBadPeerSig);
  62
  63     result = kSOSConcordanceTrusted;
  64
  65 exit:
  66     CFReleaseNull(pubKey);
  67     return result;
  68 }
  69
  70 static inline SOSConcordanceStatus CombineStatus(SOSConcordanceStatus status1, SOSConcordanceStatus status2)
  71 {
  72     if (status1 == kSOSConcordanceTrusted || status2 == kSOSConcordanceTrusted)
  73         return kSOSConcordanceTrusted;
  74
  75     if (status1 == kSOSConcordanceBadPeerSig || status2 == kSOSConcordanceBadPeerSig)
  76         return kSOSConcordanceBadPeerSig;
  77
  78     if (status1 == kSOSConcordanceNoPeerSig || status2 == kSOSConcordanceNoPeerSig)
  79         return kSOSConcordanceNoPeerSig;
  80
  81     return status1;
  82 }
  83
  84 SOSConcordanceStatus GetSignersStatus(CFSetRef peers, SOSRingRef signersRing, SOSRingRef statusRing,
  85                                                     SecKeyRef userPubkey, CFStringRef excludePeerID, CFErrorRef *error) {
  86     CFDictionaryRef ringPeerInfos = SOSPeerInfoDictionaryCreate(peers);
  87     __block SOSConcordanceStatus status = kSOSConcordanceNoPeer;
  88     SOSRingForEachPeerID(signersRing, ^(CFStringRef peerID) {
  89         SOSPeerInfoRef pi = (SOSPeerInfoRef) CFDictionaryGetValue(ringPeerInfos, peerID);
  90         SOSConcordanceStatus peerStatus = CheckPeerStatus(peerID, pi, statusRing, userPubkey, error);
  91
  92         secnotice("ring", "concordance-signer-status: %@ -> %d", peerID, peerStatus);
  93
  94         if (peerStatus == kSOSConcordanceNoPeerSig &&
  95             (CFEqualSafe(SOSPeerInfoGetPeerID(pi), excludePeerID) || SOSPeerInfoIsCloudIdentity(pi)))
  96             peerStatus = kSOSConcordanceNoPeer;
  97
  98         status = CombineStatus(status, peerStatus);
  99     });
 100
 101     return status;
 102 }
 103
 104
 105 SOSConcordanceStatus GetSignersStatus_Transitive(CFSetRef peers, SOSRingRef signersRing, SOSRingRef statusRing,
 106                                                  SecKeyRef userPubkey, CFStringRef excludePeerID, CFErrorRef *error) {
 107     __block SOSConcordanceStatus status = kSOSConcordanceNoPeer;
 108
 109     CFSetForEach(peers, ^(const void *value) {
 110         SOSPeerInfoRef pi = (SOSPeerInfoRef) value;
 111         CFStringRef peerID = SOSPeerInfoGetPeerID(pi);
 112         if(SOSRingHasPeerWithID(statusRing, peerID, NULL)) {
 113             SOSConcordanceStatus peerStatus = CheckPeerStatus(peerID, pi, statusRing, userPubkey, error);
 114
 115             if (peerStatus == kSOSConcordanceNoPeerSig &&
 116                 (CFEqualSafe(SOSPeerInfoGetPeerID(pi), excludePeerID) || SOSPeerInfoIsCloudIdentity(pi)))
 117                 peerStatus = kSOSConcordanceNoPeer;
 118
 119             status = CombineStatus(status, peerStatus);
 120         }
 121     });
 122
 123     return status;
 124 }
 125
 126
 127 SOSConcordanceStatus SOSRingUserKeyConcordanceTrust(SOSFullPeerInfoRef me, CFSetRef peers, SOSRingRef knownRing, SOSRingRef proposedRing,
 128                                                     SecKeyRef knownPubkey, SecKeyRef userPubkey,
 129                                                     CFStringRef excludePeerID, CFErrorRef *error) {
 130     if(userPubkey == NULL) {
 131         SOSCreateError(kSOSErrorPublicKeyAbsent, CFSTR("Concordance with no public key"), NULL, error);
 132         return kSOSConcordanceNoUserKey;
 133     }
 134
 135     if (SOSRingIsEmpty_Internal(proposedRing)) {
 136         return kSOSConcordanceTrusted;
 137     }
 138
 139     if(!SOSRingVerifySignatureExists(proposedRing, userPubkey, error)) {
 140         SOSCreateError(kSOSErrorBadSignature, CFSTR("No public signature"), (error != NULL) ? *error : NULL, error);
 141         return kSOSConcordanceNoUserSig;
 142     }
 143
 144     if(!SOSRingVerify(proposedRing, userPubkey, error)) {
 145         SOSCreateError(kSOSErrorBadSignature, CFSTR("Bad public signature"), (error != NULL) ? *error : NULL, error);
 146         return kSOSConcordanceBadUserSig;
 147     }
 148
 149     if (SOSRingIsEmpty_Internal(knownRing) || SOSRingIsOffering_Internal(proposedRing)) {
 150         return GetSignersStatus(peers, proposedRing, proposedRing, userPubkey, NULL, error);
 151     }
 152
 153     if(SOSRingIsOlderGeneration(proposedRing, knownRing)) {
 154         SOSCreateError(kSOSErrorReplay, CFSTR("Bad generation"), NULL, error);
 155         return kSOSConcordanceGenOld;
 156     }
 157
 158     if(knownPubkey == NULL) knownPubkey = userPubkey;
 159     if(!SOSRingVerify(knownRing, knownPubkey, error)) knownPubkey = userPubkey;
 160     return GetSignersStatus(peers, knownRing, proposedRing, knownPubkey, CFSTR("novalue"), error);
 161 }
 162
 163
 164 SOSConcordanceStatus SOSRingPeerKeyConcordanceTrust(SOSFullPeerInfoRef me, CFSetRef peers, SOSRingRef knownRing, SOSRingRef proposedRing,
 165                                                     __unused SecKeyRef knownPubkey, SecKeyRef userPubkey,
 166                                                     CFStringRef excludePeerID, CFErrorRef *error) {
 167     if(userPubkey == NULL) {
 168         SOSCreateError(kSOSErrorPublicKeyAbsent, CFSTR("Concordance with no public key - need to validate application"), NULL, error);
 169         return kSOSConcordanceNoUserKey;
 170     }
 171
 172     if (SOSRingIsEmpty_Internal(proposedRing)) {
 173         secnotice("ring", "ring empty -> trusted");
 174         return kSOSConcordanceTrusted;
 175     }
 176
 177     if (SOSRingIsEmpty_Internal(knownRing) || SOSRingIsOffering_Internal(proposedRing)) {
 178         return GetSignersStatus(peers, proposedRing, proposedRing, userPubkey, NULL, error);
 179     }
 180
 181     if(SOSRingIsOlderGeneration(proposedRing, knownRing)) {
 182         SOSCreateError(kSOSErrorReplay, CFSTR("Bad generation"), NULL, error);
 183         return kSOSConcordanceGenOld;
 184     }
 185     return GetSignersStatus(peers, knownRing, proposedRing, userPubkey, excludePeerID, error);
 186 }