SecurityServer/Authorization/AuthorizationEngine.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  *  AuthorizationEngine.cpp
  21  *  Authorization
  22  *
  23  *  Created by Michael Brouwer on Thu Oct 12 2000.
  24  *  Copyright (c) 2000 Apple Computer Inc. All rights reserved.
  25  *
  26  */
  27 #include "AuthorizationEngine.h"
  28 #include <Security/AuthorizationWalkers.h>
  29 #include "AuthorizationPriv.h"
  30 #include "AuthorizationDB.h"
  31
  32
  33 #include "authority.h"
  34
  35 #include <Security/AuthorizationTags.h>
  36 #include <Security/logging.h>
  37 #include <Security/cfutilities.h>
  38 #include <Security/debugging.h>
  39 #include "session.h"
  40 #include "server.h"
  41
  42 #include <CoreFoundation/CFData.h>
  43 #include <CoreFoundation/CFNumber.h>
  44 #include <CoreFoundation/CFPropertyList.h>
  45
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <float.h>
  49
  50 namespace Authorization {
  51
  52
  53 //
  54 // Errors to be thrown
  55 //
  56 Error::Error(int err) : error(err)
  57 {
  58 }
  59
  60 const char *Error::what() const throw()
  61 { return "Authorization error"; }
  62
  63 CSSM_RETURN Error::cssmError() const throw()
  64 { return error; }       // @@@ eventually...
  65
  66 OSStatus Error::osStatus() const throw()
  67 { return error; }
  68
  69 void Error::throwMe(int err) { throw Error(err); }
  70
  71 //
  72 // Engine class
  73 //
  74 Engine::Engine(const char *configFile) : mAuthdb(configFile)
  75 {
  76 }
  77
  78 Engine::~Engine()
  79 {
  80 }
  81
  82
  83 /*!
  84         @function AuthorizationEngine::authorize
  85
  86         @@@.
  87
  88         @param inRights (input) List of rights being requested for authorization.
  89         @param environment (optional/input) Environment containing information to be used during evaluation.
  90         @param flags (input) Optional flags @@@ see AuthorizationCreate for a description.
  91         @param inCredentials (input) Credentials already held by the caller.
  92         @param outCredentials (output/optional) Credentials obtained, used or refreshed during this call to authorize the requested rights.
  93         @param outRights (output/optional) Subset of inRights which were actually authorized.
  94
  95         @results Returns errAuthorizationSuccess if all rights requested are authorized, or if the kAuthorizationFlagPartialRights flag was specified.  Might return other status values like errAuthorizationDenied, errAuthorizationCanceled or errAuthorizationInteractionNotAllowed
  96 */
  97 OSStatus
  98 Engine::authorize(const AuthItemSet &inRights, const AuthItemSet &environment,
  99         AuthorizationFlags flags, const CredentialSet *inCredentials, CredentialSet *outCredentials,
 100         AuthItemSet &outRights, AuthorizationToken &auth)
 101 {
 102         CredentialSet credentials;
 103         OSStatus status = errAuthorizationSuccess;
 104
 105         // Get current time of day.
 106         CFAbsoluteTime now = CFAbsoluteTimeGetCurrent();
 107
 108         // Update rules from database if needed
 109         mAuthdb.sync(now);
 110
 111         // Check if a credential was passed into the environment and we were asked to extend the rights
 112         if (flags & kAuthorizationFlagExtendRights)
 113         {
 114                 string username, password;
 115                 bool shared = false;
 116                 for (AuthItemSet::iterator item = environment.begin(); item != environment.end(); item ++)
 117                 {
 118                         if (!strcmp((*item)->name(), kAuthorizationEnvironmentUsername))
 119                                 username = (*item)->stringValue();
 120                         else if (!strcmp((*item)->name(), kAuthorizationEnvironmentPassword))
 121                                 password = (*item)->stringValue();
 122                         else if (!strcmp((*item)->name(), kAuthorizationEnvironmentShared))
 123                                 shared = true;
 124                 }
 125
 126                 if (username.length())
 127                 {
 128                         // Let's create a credential from the passed in username and password.
 129                         Credential newCredential(username, password, shared);
 130                         // If it's valid insert it into the credentials list.  Normally this is
 131                         // only done if it actually authorizes a requested right, but for this
 132                         // special case (environment) we do it even when no rights are being requested.
 133                         if (newCredential->isValid())
 134                                 credentials.insert(newCredential);
 135                 }
 136         }
 137
 138         // generate hints for every authorization
 139     AuthItemSet environmentToClient = environment;
 140
 141         AuthItemSet::const_iterator end = inRights.end();
 142         for (AuthItemSet::const_iterator it = inRights.begin(); it != end; ++it)
 143         {
 144                 // Get the rule for each right we are trying to obtain.
 145                 const Rule &toplevelRule = mAuthdb.getRule(*it);
 146                 OSStatus result = toplevelRule->evaluate(*it, toplevelRule, environmentToClient, flags, now, inCredentials, credentials, auth);
 147                 secdebug("autheval", "evaluate rule %s for right %s returned %ld.", toplevelRule->name().c_str(), (*it)->name(), result);
 148
 149                 {
 150                         CodeSigning::OSXCode *processCode = Server::connection().process.clientCode();
 151                         string processName = processCode ? processCode->canonicalPath() : "unknown";
 152                         CodeSigning::OSXCode *authCreatorCode = auth.creatorCode();
 153                         string authCreatorName = authCreatorCode ? authCreatorCode->canonicalPath() : "unknown";
 154
 155                         if (result == errAuthorizationSuccess)
 156                                 Syslog::info("Succeeded authorizing right %s by process %s for authorization created by %s.", (*it)->name(), processName.c_str(), authCreatorName.c_str());
 157                         else if (result == errAuthorizationDenied)
 158                                 Syslog::notice("Failed to authorize right %s by process %s for authorization created by %s.", (*it)->name(), processName.c_str(), authCreatorName.c_str());
 159                 }
 160
 161                 if (result == errAuthorizationSuccess)
 162                         outRights.insert(*it);
 163                 else if (result == errAuthorizationDenied || result == errAuthorizationInteractionNotAllowed)
 164                 {
 165                         // add creator pid to authorization token
 166                         if (!(flags & kAuthorizationFlagPartialRights))
 167                         {
 168                                 status = result;
 169                                 break;
 170                         }
 171                 }
 172         else if (result == errAuthorizationCanceled)
 173         {
 174             status = result;
 175             break;
 176         }
 177                 else
 178                 {
 179                         Syslog::error("Engine::authorize: Rule::evaluate returned %ld returning errAuthorizationInternal", result);
 180                         status = errAuthorizationInternal;
 181                         break;
 182                 }
 183         }
 184
 185         if (outCredentials)
 186                 outCredentials->swap(credentials);
 187
 188         return status;
 189 }
 190
 191 OSStatus
 192 Engine::verifyModification(string inRightName, bool remove,
 193         const CredentialSet *inCredentials, CredentialSet *outCredentials, AuthorizationToken &auth)
 194 {
 195         // Validate right
 196
 197         // meta rights are constructed as follows:
 198         // we don't allow setting of wildcard rights, so you can only be more specific
 199         // note that you should never restrict things with a wildcard right without disallowing
 200         // changes to the entire domain.  ie.
 201         //              system.privilege.               -> never
 202         //              config.add.system.privilege.    -> never
 203         //              config.modify.system.privilege. -> never
 204         //              config.delete.system.privilege. -> never
 205         // For now we don't allow any configuration of configuration rules
 206         //              config.config. -> never
 207
 208         string rightnameToCheck;
 209
 210         // @@@ verify right name is is not NULL or zero length
 211         if (inRightName.length() == 0)
 212                 return errAuthorizationDenied;
 213
 214         // @@@ make sure it isn't a wildcard right by checking trailing "."
 215         if ( *(inRightName.rbegin()) == '.')
 216                 return errAuthorizationDenied;
 217
 218         // @@@ make sure it isn't a configure right by checking it doesn't start with config.
 219         if (inRightName.find(kConfigRight, 0) != string::npos)
 220         {
 221                 // special handling of meta right change:
 222                 // config.add. config.modify. config.remove. config.{}.
 223                 // check for config.<right> (which always starts with config.config.)
 224                 rightnameToCheck = string(kConfigRight) + inRightName;
 225         }
 226         else
 227         {
 228                 // regular check of rights
 229                 bool existingRule = mAuthdb.existRule(inRightName);
 230                 if (!remove)
 231                 {
 232                         if (existingRule)
 233                                 rightnameToCheck = string(kAuthorizationConfigRightModify) + inRightName;
 234                         else
 235                                 rightnameToCheck = string(kAuthorizationConfigRightAdd) + inRightName;
 236                 }
 237                 else
 238                 {
 239                         if (existingRule)
 240                                 rightnameToCheck = string(kAuthorizationConfigRightRemove) + inRightName;
 241                         else
 242                         {
 243                                 secdebug("engine", "rule %s doesn't exist.", inRightName.c_str());
 244                                 return errAuthorizationSuccess; // doesn't exist, done
 245                         }
 246                 }
 247         }
 248
 249
 250         AuthItemSet rights, environment, outRights;
 251         rights.insert(AuthItemRef(rightnameToCheck.c_str()));
 252         secdebug("engine", "authorizing %s for db modification.", rightnameToCheck.c_str());
 253         return authorize(rights, environment, kAuthorizationFlagDefaults | kAuthorizationFlagInteractionAllowed | kAuthorizationFlagExtendRights, inCredentials, outCredentials, outRights, auth);
 254 }
 255
 256 OSStatus
 257 Engine::getRule(string &inRightName, CFDictionaryRef *outRuleDefinition)
 258 {
 259         // Get current time of day.
 260         CFAbsoluteTime now = CFAbsoluteTimeGetCurrent();
 261
 262         // Update rules from database if needed
 263         mAuthdb.sync(now);
 264
 265         CFDictionaryRef definition = mAuthdb.getRuleDefinition(inRightName);
 266         if (definition)
 267         {
 268                 if (outRuleDefinition)
 269                         *outRuleDefinition = definition;
 270                 else
 271                         CFRelease(definition);
 272
 273                 return errAuthorizationSuccess;
 274         }
 275
 276         return errAuthorizationDenied;
 277 }
 278
 279 OSStatus
 280 Engine::setRule(const char *inRightName, CFDictionaryRef inRuleDefinition, const CredentialSet *inCredentials, CredentialSet *outCredentials, AuthorizationToken &auth)
 281 {
 282         // Get current time of day.
 283         CFAbsoluteTime now = CFAbsoluteTimeGetCurrent();
 284
 285         // Update rules from database if needed
 286         mAuthdb.sync(now);
 287
 288         // Validate rule by constructing it from the passed dictionary
 289         if (!mAuthdb.validateRule(inRightName, inRuleDefinition))
 290                 return errAuthorizationDenied; // @@@ separate error for this?
 291
 292         OSStatus result = verifyModification(inRightName, false /*setting, not removing*/, inCredentials, outCredentials, auth);
 293         if (result != errAuthorizationSuccess)
 294                 return result;
 295
 296         // set the rule for the right and save the database
 297         mAuthdb.setRule(inRightName, inRuleDefinition);
 298
 299         return errAuthorizationSuccess;
 300 }
 301
 302 OSStatus
 303 Engine::removeRule(const char *inRightName, const CredentialSet *inCredentials, CredentialSet *outCredentials, AuthorizationToken &auth)
 304 {
 305         // Get current time of day.
 306         CFAbsoluteTime now = CFAbsoluteTimeGetCurrent();
 307
 308         // Update rules from database if needed
 309         mAuthdb.sync(now);
 310
 311         OSStatus result = verifyModification(inRightName, true /*removing*/, inCredentials, outCredentials, auth);
 312         if (result != errAuthorizationSuccess)
 313                 return result;
 314
 315         // set the rule for the right and save the database
 316         mAuthdb.removeRule(inRightName);
 317
 318         return errAuthorizationSuccess;
 319 }
 320
 321 }       // end namespace Authorization