securityd/src/kckey.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2004-2006,2008-2009 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 //
  26 // key - representation of securityd key objects
  27 //
  28 #include "kckey.h"
  29 #include "server.h"
  30 #include "database.h"
  31 #include <security_cdsa_utilities/acl_any.h>
  32 #include <security_cdsa_utilities/cssmendian.h>
  33
  34
  35 //
  36 // Create a Key object from a database-encoded blob.
  37 // Note that this doesn't decode the blob (yet).
  38 //
  39 KeychainKey::KeychainKey(Database &db, const KeyBlob *blob)
  40         : LocalKey(db, n2h(blob->header.attributes()))
  41 {
  42     // perform basic validation on the incoming blob
  43         assert(blob);
  44     blob->validate(CSSMERR_APPLEDL_INVALID_KEY_BLOB);
  45     if (blob->startCryptoBlob > blob->totalLength) {
  46         CssmError::throwMe(CSSMERR_APPLEDL_INVALID_KEY_BLOB);
  47     }
  48     switch (blob->version()) {
  49 #if defined(COMPAT_OSX_10_0)
  50     case KeyBlob::version_MacOS_10_0:
  51         break;
  52 #endif
  53     case KeyBlob::version_MacOS_10_1:
  54         break;
  55     case KeyBlob::version_partition:
  56         break;
  57     default:
  58         CssmError::throwMe(CSSMERR_APPLEDL_INCOMPATIBLE_KEY_BLOB);
  59     }
  60
  61     // set it up
  62     mBlob = blob->copy(Allocator::standard());
  63         mValidBlob = true;
  64         db.addReference(*this);
  65     secinfo("SSkey", "%p (handle %#x) created from blob version %x",
  66                 this, handle(), blob->version());
  67 }
  68
  69
  70 //
  71 // Create a Key from an explicit CssmKey.
  72 //
  73 KeychainKey::KeychainKey(Database &db, const CssmKey &newKey, uint32 moreAttributes,
  74         const AclEntryPrototype *owner)
  75         : LocalKey(db, newKey, moreAttributes)
  76 {
  77         assert(moreAttributes & CSSM_KEYATTR_PERMANENT);
  78         setOwner(owner);
  79     mBlob = NULL;
  80         mValidBlob = false;
  81         db.addReference(*this);
  82 }
  83
  84
  85 KeychainKey::~KeychainKey()
  86 {
  87     Allocator::standard().free(mBlob);
  88     secinfo("SSkey", "%p destroyed", this);
  89 }
  90
  91
  92 KeychainDatabase &KeychainKey::database() const
  93 {
  94         return referent<KeychainDatabase>();
  95 }
  96
  97
  98 //
  99 // Retrieve the actual CssmKey value for the key object.
 100 // This will decode its blob if needed (and appropriate).
 101 //
 102 void KeychainKey::getKey()
 103 {
 104     decode();
 105 }
 106
 107 void KeychainKey::getHeader(CssmKey::Header &hdr)
 108 {
 109         assert(mValidBlob);
 110         hdr = mBlob->header;
 111         n2hi(hdr);      // correct for endian-ness
 112 }
 113
 114
 115 //
 116 // Ensure that a key is fully decoded.
 117 // This makes the mKey key value available for use, as well as its ACL.
 118 // Caller must hold the key object lock.
 119 //
 120 void KeychainKey::decode()
 121 {
 122         if (!mValidKey) {
 123                 assert(mValidBlob);     // must have a blob to decode
 124
 125         // decode the key
 126         void *publicAcl, *privateAcl;
 127                 CssmKey key;
 128         database().decodeKey(mBlob, key, publicAcl, privateAcl);
 129                 mKey = CssmClient::Key(Server::csp(), key);
 130         acl().importBlob(publicAcl, privateAcl);
 131         // publicAcl points into the blob; privateAcl was allocated for us
 132         Allocator::standard().free(privateAcl);
 133
 134         // extract managed attribute bits
 135         mAttributes = mKey.header().attributes() & managedAttributes;
 136         mKey.header().clearAttribute(managedAttributes);
 137                 mKey.header().setAttribute(forcedAttributes);
 138
 139         // key is valid now
 140                 mValidKey = true;
 141         }
 142 }
 143
 144
 145 //
 146 // Encode a key into a blob.
 147 // We'll have to ask our Database to do this - we don't have its keys.
 148 // Note that this returns memory we own and keep.
 149 //
 150 KeyBlob *KeychainKey::blob()
 151 {
 152         if (!mValidBlob) {
 153         assert(mValidKey);              // must have valid key to encode
 154
 155         // export Key ACL to blob form
 156         CssmData pubAcl, privAcl;
 157                 acl().exportBlob(pubAcl, privAcl);
 158
 159         // assemble external key form
 160         CssmKey externalKey = mKey;
 161                 externalKey.clearAttribute(forcedAttributes);
 162         externalKey.setAttribute(mAttributes);
 163
 164         // encode the key and replace blob
 165         KeyBlob *newBlob = database().encodeKey(externalKey, pubAcl, privAcl);
 166         Allocator::standard().free(mBlob);
 167         mBlob = newBlob;
 168         mValidBlob = true;
 169
 170         // clean up and go
 171         acl().allocator.free(pubAcl);
 172         acl().allocator.free(privAcl);
 173         }
 174         return mBlob;
 175 }
 176
 177 void KeychainKey::invalidateBlob()
 178 {
 179         mValidBlob = false;
 180 }
 181
 182
 183 //
 184 // Override ACL-related methods and events.
 185 // Decode the key before ACL activity; invalidate the stored blob on ACL edits;
 186 // and return the key's database as "related".
 187 //
 188 void KeychainKey::instantiateAcl()
 189 {
 190         StLock<Mutex> _(*this);
 191         decode();
 192 }
 193
 194 void KeychainKey::changedAcl()
 195 {
 196         invalidateBlob();
 197 }
 198
 199
 200 //
 201 // Intercept Key validation and double-check that the keychain is (still) unlocked
 202 //
 203 void KeychainKey::validate(AclAuthorization auth, const AccessCredentials *cred,
 204         Database *relatedDatabase)
 205 {
 206         if(!mBlob->isClearText()) {
 207                 /* unlock not needed for cleartext keys */
 208                 if (KeychainDatabase *db = dynamic_cast<KeychainDatabase *>(relatedDatabase))
 209                         db->unlockDb(false);
 210         }
 211         SecurityServerAcl::validate(auth, cred, relatedDatabase);
 212
 213     // Need the common lock some more. unlockDb and validate (in validatePartition) also take it, so must be down here.
 214     StMaybeLock<Mutex> lock(relatedDatabase && relatedDatabase->hasCommon() ? &(relatedDatabase->common()) : NULL);
 215         database().activity();          // upon successful validation
 216 }
 217
 218
 219 //
 220 // We're a key (duh)
 221 //
 222 AclKind KeychainKey::aclKind() const
 223 {
 224         return keyAcl;
 225 }
 226
 227
 228 Database *KeychainKey::relatedDatabase()
 229 {
 230         return &database();
 231 }
 232
 233 SecurityServerAcl &KeychainKey::acl()
 234 {
 235         return *this;
 236 }