SecurityServer/acl_keychain.cpp

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // acl_keychain - a subject type for the protected-path
  21 //                                keychain prompt interaction model.
  22 //
  23 // Arguments in list form:
  24 //      list[1] = CssmData: Descriptive String (presented to user in protected dialogs)
  25 //
  26 // Some notes on Acl Update Triggers:
  27 // When the user checks the "don't ask me again" checkbox in the access confirmation
  28 // dialog, we respond by returning the informational error code
  29 // CSSMERR_CSP_APPLE_ADD_APPLICATION_ACL_SUBJECT, and setting a count-down trigger
  30 // in the connection. The caller is entitled to bypass our dialog (it succeeds
  31 // automatically) within the next few (Connection::aclUpdateTriggerLimit == 2)
  32 // requests, in order to update the object's ACL as requested. It must then retry
  33 // the original access operation (which will presumably pass because of that edit).
  34 // These are the rules: for the trigger to apply, the access must be to the same
  35 // object, from the same connection, and within the next two accesses.
  36 // (Currently, these are for a "get acl" and the "change acl" calls.)
  37 // Damage Control Department: The worst this mechanism could do, if subverted, is
  38 // to bypass our confirmation dialog (making it appear to succeed to the ACL validation).
  39 // But that is exactly what the "don't ask me again" checkbox is meant to do, so any
  40 // subversion would be based on a (perhaps intentional) miscommunication between user
  41 // and client process as to what the user consents not to be asked about (any more).
  42 // The user can always examine the resulting ACL (in Keychain Access or elsewhere), and
  43 // edit it to suit her needs.
  44 //
  45 #ifdef __MWERKS__
  46 #define _CPP_ACL_KEYCHAIN
  47 #endif
  48
  49 #include "acl_keychain.h"
  50 #include "agentquery.h"
  51 #include "acls.h"
  52 #include "connection.h"
  53 #include "xdatabase.h"
  54 #include "server.h"
  55 #include <Security/debugging.h>
  56 #include <algorithm>
  57
  58
  59 //
  60 // Validate a credential set against this subject.
  61 //
  62 bool KeychainPromptAclSubject::validate(const AclValidationContext &context,
  63     const TypedList &sample) const
  64 {
  65     SecurityServerEnvironment *env = context.environment<SecurityServerEnvironment>();
  66     if (env) {
  67                 // check for special ACL-update override
  68                 if (context.authorization() == CSSM_ACL_AUTHORIZATION_CHANGE_ACL
  69                                 && Server::connection().aclWasSetForUpdateTrigger(env->acl)) {
  70                         debug("kcacl", "honoring acl update trigger for %p(%s)",
  71                 &env->acl, description.c_str());
  72                         return true;
  73                 }
  74
  75         // ask the user
  76                 QueryKeychainUse query;
  77                 const Database *db = env->database();
  78                 query((db ? db->dbName() : NULL), description.c_str(), context.authorization());
  79                 if (query.continueGrantingToCaller) {
  80                         // mark for special ACL-update override (really soon) later
  81                         Server::connection().setAclUpdateTrigger(env->acl);
  82                         debug("kcacl", "setting acl update trigger for %p(%s)",
  83                 &env->acl, description.c_str());
  84                         // fail with prejudice (caller will retry)
  85                         CssmError::throwMe(CSSMERR_CSP_APPLE_ADD_APPLICATION_ACL_SUBJECT);
  86                 }
  87                 return query.allowAccess;
  88     }
  89         return false;        // default to deny without prejudice
  90 }
  91
  92
  93 //
  94 // Make a copy of this subject in CSSM_LIST form
  95 //
  96 CssmList KeychainPromptAclSubject::toList(CssmAllocator &alloc) const
  97 {
  98         return TypedList(alloc, CSSM_ACL_SUBJECT_TYPE_KEYCHAIN_PROMPT,
  99         new(alloc) ListElement(alloc, description));
 100 }
 101
 102
 103 //
 104 // Create a PasswordAclSubject
 105 //
 106 KeychainPromptAclSubject *KeychainPromptAclSubject::Maker::make(const TypedList &list) const
 107 {
 108     ListElement *params[1];
 109         crack(list, 1, params, CSSM_LIST_ELEMENT_DATUM);
 110         return new KeychainPromptAclSubject(*params[0]);
 111 }
 112
 113 KeychainPromptAclSubject *KeychainPromptAclSubject::Maker::make(Reader &pub, Reader &) const
 114 {
 115     const char *description; pub(description);
 116         return new KeychainPromptAclSubject(description);
 117 }
 118
 119 KeychainPromptAclSubject::KeychainPromptAclSubject(string descr)
 120 : SimpleAclSubject(CSSM_ACL_SUBJECT_TYPE_KEYCHAIN_PROMPT, CSSM_SAMPLE_TYPE_KEYCHAIN_PROMPT),
 121   description(descr)
 122 {
 123 }
 124
 125
 126 //
 127 // Export the subject to a memory blob
 128 //
 129 void KeychainPromptAclSubject::exportBlob(Writer::Counter &pub, Writer::Counter &priv)
 130 {
 131     pub.insert(description.size() + 1);
 132 }
 133
 134 void KeychainPromptAclSubject::exportBlob(Writer &pub, Writer &priv)
 135 {
 136     pub(description.c_str());
 137 }
 138
 139
 140 #ifdef DEBUGDUMP
 141
 142 void KeychainPromptAclSubject::debugDump() const
 143 {
 144         Debug::dump("KeychainPrompt:%s", description.c_str());
 145 }
 146
 147 #endif //DEBUGDUMP