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