OSX/sec/SOSCircle/SecureObjectSync/SOSChangeTracker.c

   1 /*
   2  * Copyright (c) 2015 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  * SOSChangeTracker.c -  Implementation of a manifest caching change tracker that forwards changes to children
  26  */
  27
  28 #include <Security/SecureObjectSync/SOSChangeTracker.h>
  29 #include <Security/SecureObjectSync/SOSDigestVector.h>
  30 #include <Security/SecureObjectSync/SOSEngine.h>
  31 #include <Security/SecureObjectSync/SOSManifest.h>
  32 #include <Security/SecureObjectSync/SOSInternal.h>
  33 #include <utilities/SecCFError.h>
  34 #include <utilities/SecCFWrappers.h>
  35
  36 CFStringRef SOSChangeCopyDescription(SOSChangeRef change) {
  37     CFTypeRef object = NULL;
  38     bool isAdd = SOSChangeGetObject(change, &object);
  39     // TODO: Print objects or digests
  40     return (isData(object)
  41             ? isAdd ? CFSTR("a") : CFSTR("d")
  42             : isAdd ? CFSTR("A") : CFSTR("D"));
  43 }
  44
  45 CFDataRef SOSChangeCopyDigest(SOSDataSourceRef dataSource, SOSChangeRef change, bool *isDel, SOSObjectRef *object, CFErrorRef *error) {
  46     CFDataRef digest = NULL;
  47     if (isArray(change)) {
  48         if (CFArrayGetCount(change) != 1) {
  49             SecError(errSecDecode, error, CFSTR("change array count: %ld"), CFArrayGetCount(change));
  50             return NULL;
  51         }
  52         change = CFArrayGetValueAtIndex(change, 0);
  53         *isDel = true;
  54     } else {
  55         *isDel = false;
  56     }
  57
  58     // If the change is a CFData, this is the signal that it is a delete
  59     if (isData(change)) {
  60         digest = (CFDataRef)CFRetain(change);
  61     } else {
  62         digest = SOSObjectCopyDigest(dataSource, (SOSObjectRef)change, error);
  63         *object = (SOSObjectRef)change;
  64     }
  65     assert(digest && CFDataGetLength(digest) == CCSHA1_OUTPUT_SIZE);
  66     return digest;
  67 }
  68
  69 CFStringRef SOSChangesCopyDescription(CFArrayRef changes) {
  70     CFMutableStringRef desc = CFStringCreateMutableCopy(kCFAllocatorDefault, 0, CFSTR("("));
  71     CFTypeRef change;
  72     if (changes) CFArrayForEachC(changes, change) {
  73         CFStringRef changeDesc = SOSChangeCopyDescription(change);
  74         CFStringAppend(desc, changeDesc);
  75         CFRetainSafe(changeDesc);
  76     }
  77     CFStringAppend(desc, CFSTR(")"));
  78     return desc;
  79 }
  80
  81
  82 /* SOSChangeTracker implementation. */
  83 struct __OpaqueSOSChangeTracker {
  84     CFRuntimeBase _base;
  85     SOSManifestRef manifest;                // Optional: Only concrete cts have a manifest
  86     CFMutableArrayRef changeChildren;       // Optional: cts can have children
  87     CFMutableArrayRef manifestChildren;     // Optional: cts can have children
  88 };
  89
  90 static CFStringRef SOSChangeTrackerCopyFormatDescription(CFTypeRef cf, CFDictionaryRef formatOptions) {
  91     SOSChangeTrackerRef ct = (SOSChangeTrackerRef)cf;
  92     CFStringRef desc = CFStringCreateWithFormat(kCFAllocatorDefault, formatOptions, CFSTR("<ChangeTracker %@ children %ld/%ld>"),
  93                                                 ct->manifest ? ct->manifest : (SOSManifestRef)CFSTR("NonConcrete"),
  94                                                 CFArrayGetCount(ct->changeChildren), CFArrayGetCount(ct->manifestChildren));
  95     return desc;
  96 }
  97
  98 static void SOSChangeTrackerDestroy(CFTypeRef cf) {
  99     SOSChangeTrackerRef ct = (SOSChangeTrackerRef)cf;
 100     CFReleaseSafe(ct->manifest);
 101     CFReleaseSafe(ct->changeChildren);
 102     CFReleaseSafe(ct->manifestChildren);
 103 }
 104
 105 // Even though SOSChangeTracker instances are used as keys in dictionaries, they are treated as pointers when used as such
 106 // which is fine since the engine ensures instances are singletons.
 107 CFGiblisFor(SOSChangeTracker);
 108
 109 SOSChangeTrackerRef SOSChangeTrackerCreate(CFAllocatorRef allocator, bool isConcrete, CFArrayRef changeChildren, CFErrorRef *error) {
 110     SOSChangeTrackerRef ct = NULL;
 111     ct = CFTypeAllocate(SOSChangeTracker, struct __OpaqueSOSChangeTracker, allocator);
 112     if (ct && isConcrete) {
 113         ct->manifest = SOSManifestCreateWithData(NULL, error);
 114         if (!ct->manifest)
 115             CFReleaseNull(ct);
 116     }
 117     if (ct) {
 118         if (changeChildren)
 119             ct->changeChildren = CFArrayCreateMutableCopy(kCFAllocatorDefault, 0, changeChildren);
 120         else
 121             ct->changeChildren = CFArrayCreateMutableForCFTypes(kCFAllocatorDefault);
 122         ct->manifestChildren = CFArrayCreateMutableForCFTypes(kCFAllocatorDefault);
 123     }
 124
 125     return ct;
 126 }
 127
 128 // Change the concreteness of the current ct (a non concrete ct does not support SOSChangeTrackerCopyManifest().
 129 void SOSChangeTrackerSetConcrete(SOSChangeTrackerRef ct, bool isConcrete) {
 130     if (!isConcrete)
 131         CFReleaseNull(ct->manifest);
 132     else if (!ct->manifest) {
 133         ct->manifest = SOSManifestCreateWithData(NULL, NULL);
 134     }
 135 }
 136
 137 // Add a child to the current ct
 138 void SOSChangeTrackerRegisterChangeUpdate(SOSChangeTrackerRef ct, SOSChangeTrackerUpdatesChanges child) {
 139     CFArrayAppendValue(ct->changeChildren, child);
 140 }
 141
 142 void SOSChangeTrackerRegisterManifestUpdate(SOSChangeTrackerRef ct, SOSChangeTrackerUpdatesManifests child) {
 143     CFArrayAppendValue(ct->manifestChildren, child);
 144 }
 145
 146 void SOSChangeTrackerResetRegistration(SOSChangeTrackerRef ct) {
 147     CFArrayRemoveAllValues(ct->changeChildren);
 148     CFArrayRemoveAllValues(ct->manifestChildren);
 149 }
 150
 151 void SOSChangeTrackerSetManifest(SOSChangeTrackerRef ct, SOSManifestRef manifest) {
 152     CFRetainAssign(ct->manifest, manifest);
 153 }
 154
 155 SOSManifestRef SOSChangeTrackerCopyManifest(SOSChangeTrackerRef ct, CFErrorRef *error) {
 156     if (ct->manifest) {
 157         return (SOSManifestRef)CFRetain(ct->manifest);
 158     }
 159     SOSErrorCreate(kSOSErrorNotConcreteError, error, NULL, CFSTR("ChangeTracker is not concrete"));
 160     return NULL;
 161 }
 162
 163 static bool SOSChangeTrackerCreateManifestsWithChanges(SOSEngineRef engine, CFArrayRef changes, SOSManifestRef *removals, SOSManifestRef *additions, CFErrorRef *error) {
 164     bool ok = true;
 165     struct SOSDigestVector dvdels = SOSDigestVectorInit;
 166     struct SOSDigestVector dvadds = SOSDigestVectorInit;
 167     struct SOSDigestVector *dv;
 168     CFTypeRef change;
 169     CFArrayForEachC(changes, change) {
 170         CFDataRef digest, allocatedDigest = NULL;
 171         if (isArray(change)) {
 172             assert(CFArrayGetCount(change) == 1);
 173             change = CFArrayGetValueAtIndex(change, 0);
 174             dv = &dvdels;
 175         } else {
 176             dv = &dvadds;
 177         }
 178
 179         if (isData(change)) {
 180             digest = (CFDataRef)change;
 181         } else {
 182             CFErrorRef digestError = NULL;
 183             digest = allocatedDigest = SOSObjectCopyDigest(SOSEngineGetDataSource(engine), (SOSObjectRef)change, &digestError);
 184             if (!digest) {
 185                 secerror("change %@ SOSObjectCopyDigest: %@", change, digestError);
 186                 CFReleaseNull(digestError);
 187                 continue;
 188             }
 189         }
 190
 191         if (CFDataGetLength(digest) == 20) {
 192             SOSDigestVectorAppend(dv, CFDataGetBytePtr(digest));
 193         } else {
 194             secerror("change %@ bad length digest: %@", change, digest);
 195         }
 196         CFReleaseNull(allocatedDigest);
 197     }
 198     if (ok && removals)
 199         ok = *removals = SOSManifestCreateWithDigestVector(&dvdels, error);
 200     if (ok && additions)
 201         ok = *additions = SOSManifestCreateWithDigestVector(&dvadds, error);
 202
 203     SOSDigestVectorFree(&dvadds);
 204     SOSDigestVectorFree(&dvdels);
 205
 206     return ok;
 207 }
 208
 209 bool SOSChangeTrackerTrackChanges(SOSChangeTrackerRef ct, SOSEngineRef engine, SOSTransactionRef txn, SOSDataSourceTransactionSource source, SOSDataSourceTransactionPhase phase, CFArrayRef changes, CFErrorRef *error) {
 210     bool ok = true;
 211     if (changes && CFArrayGetCount(changes)) {
 212         CFStringRef changesDesc = SOSChangesCopyDescription(changes);
 213         secnotice("tracker", "%@ %s %s changes: %@", ct, phase == kSOSDataSourceTransactionWillCommit ? "will-commit" : phase == kSOSDataSourceTransactionDidCommit ? "did-commit" : "did-rollback", source == kSOSDataSourceSOSTransaction ? "sos" : "api", changesDesc);
 214         CFReleaseSafe(changesDesc);
 215         if (ct->manifest || ct->manifestChildren) {
 216             SOSManifestRef additions = NULL;
 217             SOSManifestRef removals = NULL;
 218             ok &= SOSChangeTrackerCreateManifestsWithChanges(engine, changes, &removals, &additions, error);
 219             if (ok) {
 220                 if (ct->manifest) {
 221                     SOSManifestRef updatedManifest = SOSManifestCreateWithPatch(ct->manifest, removals, additions, error);
 222                     if (updatedManifest){
 223                         CFTransferRetained(ct->manifest, updatedManifest);
 224                     }
 225                 }
 226                 if (ct->manifestChildren) {
 227                     SOSChangeTrackerUpdatesManifests child;
 228                     CFArrayForEachC(ct->manifestChildren, child) {
 229                         ok = ok && child(ct, engine, txn, source, phase, removals, additions, error);
 230                     }
 231                 }
 232             }
 233             CFReleaseSafe(removals);
 234             CFReleaseSafe(additions);
 235             // TODO: Potentially filter changes to eliminate any changes that were already in our manifest
 236             // Backup Peers and the like would probably enjoy this so they don't have to do it themselves.
 237         }
 238
 239         if (ct->changeChildren) {
 240             SOSChangeTrackerUpdatesChanges child;
 241             CFArrayForEachC(ct->changeChildren, child) {
 242                 ok = ok && child(ct, engine, txn, source, phase, changes, error);
 243             }
 244         }
 245     }
 246
 247     return ok;
 248 }
 249