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