securityd/src/ccaudit_extensions.cpp

   1 /*
   2  *  ccaudit_extensions.cpp
   3  *  securityd
   4  *
   5  *  Created by G H on 3/24/09.
   6  *  Copyright (c) 2009 Apple Inc. All Rights Reserved.
   7  *
   8  */
   9
  10 #include <errno.h>
  11 #include <assert.h>
  12 #include <stdio.h>                  // vsnprintf()
  13 #include <stdarg.h>                 // va_start(), et al.
  14 #include <syslog.h>
  15 #include <string.h>                 // memcpy()
  16 #include <bsm/audit_uevents.h>      // AUE_ssauth*
  17 #include <bsm/libbsm.h>
  18 #include <security_utilities/errors.h>
  19 #include <security_utilities/ccaudit.h>
  20 #include "ccaudit_extensions.h"
  21
  22 namespace Security
  23 {
  24
  25 namespace CommonCriteria
  26 {
  27
  28 namespace Securityd
  29 {
  30
  31 //
  32 // AuditLogger
  33 //
  34 AuditLogger::AuditLogger(const audit_token_t *srcToken, short auEvent)
  35     : mAuditFd(-1), mEvent(auEvent), mClientInfoSet(false)
  36 {
  37     setClientInfo(srcToken);
  38 }
  39
  40 AuditLogger::AuditLogger(const AuditToken &srcToken, short auEvent)
  41     : mAuditFd(-1), mEvent(auEvent), mClientInfoSet(false)
  42 {
  43     setClientInfo(srcToken);
  44 }
  45
  46 AuditLogger::~AuditLogger()
  47 {
  48     close();
  49 }
  50
  51 bool
  52 AuditLogger::open()
  53 {
  54     if (-1 != mAuditFd)
  55         return true;
  56
  57     // @@@  use audit_get_cond() when it's available
  58     int acond = au_get_state();
  59     switch (acond)
  60     {
  61         case AUC_NOAUDIT:
  62             return false;
  63         case AUC_AUDITING:
  64             break;
  65         default:
  66             logInternalError("error checking auditing status (%d)", acond);
  67             UnixError::throwMe(acond);  // assume it's a Unix error
  68     }
  69     if ((mAuditFd = au_open()) < 0)
  70     {
  71         logInternalError("au_open() failed (%s)", strerror(errno));
  72         UnixError::throwMe(errno);
  73     }
  74     return true;
  75 }
  76
  77 void
  78 AuditLogger::close(bool writeLog/* = true*/)
  79 {
  80     if (-1 != mAuditFd)
  81     {
  82         int keep = writeLog == true ?  AU_TO_WRITE : AU_TO_NO_WRITE;
  83         int error = au_close(mAuditFd, keep, mEvent);
  84         mAuditFd = -1;
  85         if (writeLog == true && error < 0)
  86         {
  87             logInternalError("au_close() failed; record not committed");
  88             UnixError::throwMe(error);
  89         }
  90     }
  91 }
  92
  93 void
  94 AuditLogger::setClientInfo(const audit_token_t *srcToken)
  95 {
  96     assert(srcToken);
  97     audit_token_to_au32(*srcToken, &mAuditId, &mEuid, &mEgid, &mRuid, &mRgid, &mPid, &mAuditSessionId, &mOldTerminalId);
  98
  99     mTerminalId.at_type = AU_IPv4;
 100     mTerminalId.at_addr[0] = mOldTerminalId.machine;
 101     mTerminalId.at_port = mOldTerminalId.port;
 102
 103     mClientInfoSet = true;
 104 }
 105
 106 void
 107 AuditLogger::setClientInfo(const AuditToken &srcToken)
 108 {
 109     mAuditId = srcToken.auditId();
 110     mEuid = srcToken.euid();
 111     mEgid = srcToken.egid();
 112     mRuid = srcToken.ruid();
 113     mRgid = srcToken.rgid();
 114     mPid = srcToken.pid();
 115     mAuditSessionId = srcToken.sessionId();
 116     memcpy(&mOldTerminalId, &(srcToken.terminalId()), sizeof(mOldTerminalId));
 117
 118     mTerminalId.at_type = AU_IPv4;
 119     mTerminalId.at_addr[0] = mOldTerminalId.machine;
 120     mTerminalId.at_port = mOldTerminalId.port;
 121
 122     mClientInfoSet = true;
 123 }
 124
 125 void
 126 AuditLogger::writeToken(token_t *token, const char *name)
 127 {
 128     const char *tokenName = name ? name : "<unidentified>";
 129     if (NULL == token)
 130     {
 131         logInternalError("Invalid '%s' token", tokenName);
 132         close();
 133         UnixError::throwMe(EPERM);      // per audit_submit()
 134     }
 135     if (au_write(mAuditFd, token) < 0)
 136     {
 137         logInternalError("Error writing '%s' token (%s)", tokenName, strerror(errno));
 138         close();
 139         UnixError::throwMe(errno);
 140     }
 141 }
 142
 143 void
 144 AuditLogger::writeSubject()
 145 {
 146     assert(mClientInfoSet);
 147
 148     token_t *token;
 149
 150     // @@@  terminal ID is not carried in the audit trailer nowadays, but
 151     // this code should be harmless: it replicates the current logic in
 152     // audit_submit()
 153     if (AU_IPv4 == mTerminalId.at_type)
 154         token = au_to_subject32(mAuditId, mEuid, mEgid, mRuid, mRgid, mPid, mAuditSessionId, &mOldTerminalId);
 155     else
 156         token = au_to_subject_ex(mAuditId, mEuid, mEgid, mRuid, mRgid, mPid, mAuditSessionId, &mTerminalId);
 157     writeToken(token, "subject");
 158 }
 159
 160 void
 161 AuditLogger::writeReturn(char status, int reterr)
 162 {
 163     writeToken(au_to_return32(status, reterr), "return");
 164 }
 165
 166 void
 167 AuditLogger::logSuccess()
 168 {
 169     if (false == open())
 170         return;
 171     writeCommon();
 172     writeReturn(0, 0);
 173     close();
 174 }
 175
 176 void
 177 AuditLogger::logFailure(const char *errMsg, int errcode)
 178 {
 179     if (false == open())
 180         return;
 181     writeCommon();
 182     if (errMsg)
 183         writeToken(au_to_text(errMsg), "evaluation error");
 184     writeReturn(EPERM, errcode);
 185     close();
 186 }
 187
 188 // cribbed from audit_submit()
 189 void
 190 AuditLogger::logInternalError(const char *fmt, ...)
 191 {
 192     va_list ap;
 193     char text[MAX_AUDITSTRING_LEN];
 194
 195     if (fmt != NULL)
 196     {
 197         int error = errno;
 198         va_start(ap, fmt);
 199         (void)vsnprintf(text, MAX_AUDITSTRING_LEN, fmt, ap);
 200         va_end(ap);
 201         syslog(LOG_AUTH | LOG_ERR, "%s", text);
 202         errno = error;
 203     }
 204 }
 205
 206 //
 207 // KeychainAuthLogger
 208 //
 209 const char *KeychainAuthLogger::sysKCAuthStr = "System keychain authorization";
 210 const char *KeychainAuthLogger::unknownKCStr = "<unknown keychain>";
 211 const char *KeychainAuthLogger::unknownItemStr = "<unknown item>";
 212
 213 KeychainAuthLogger::KeychainAuthLogger(const audit_token_t *srcToken, short auEvent)
 214     : AuditLogger(srcToken, auEvent), mDatabase(unknownKCStr),
 215       mItem(unknownItemStr)
 216 {
 217 }
 218
 219 KeychainAuthLogger::KeychainAuthLogger(const AuditToken &srcToken, short auEvent)
 220     : AuditLogger(srcToken, auEvent), mDatabase(unknownKCStr),
 221       mItem(unknownItemStr)
 222 {
 223 }
 224
 225 KeychainAuthLogger::KeychainAuthLogger(const audit_token_t *srcToken, short auEvent, const char *database, const char *item)
 226     : AuditLogger(srcToken, auEvent)
 227 {
 228     setDbName(database);
 229     setItemName(item);
 230 }
 231
 232 KeychainAuthLogger::KeychainAuthLogger(const AuditToken &srcToken, short auEvent, const char *database, const char *item)
 233     : AuditLogger(srcToken, auEvent)
 234 {
 235     setDbName(database);
 236     setItemName(item);
 237 }
 238
 239 void
 240 KeychainAuthLogger::setDbName(const char *database)
 241 {
 242     mDatabase = database ? database : unknownKCStr;
 243 }
 244
 245 void
 246 KeychainAuthLogger::setItemName(const char *item)
 247 {
 248     mItem = item ? item : unknownItemStr;
 249 }
 250
 251 void
 252 KeychainAuthLogger::writeCommon()
 253 {
 254     writeSubject();
 255     writeToken(au_to_text(sysKCAuthStr), sysKCAuthStr);
 256     writeToken(au_to_text(mDatabase.c_str()), "keychain");
 257     writeToken(au_to_text(mItem.c_str()), "keychain item");
 258 }
 259
 260
 261 //
 262 // RightLogger
 263 //
 264 const char *RightLogger::unknownRightStr = "<unknown right>";
 265
 266 void
 267 RightLogger::setRight(const string &rightName)
 268 {
 269     mRight.clear();
 270     mRight = rightName;
 271 }
 272
 273 void
 274 RightLogger::setRight(const char *rightName)
 275 {
 276     if (rightName)      // NULL bad for string class and au_to_text()
 277     {
 278         string tmpStr(rightName);   // setRight() takes a string&
 279         setRight(tmpStr);
 280     }
 281 }
 282
 283
 284 //
 285 // AuthMechLogger
 286 //
 287 const char *AuthMechLogger::unknownMechStr = "<unknown mechanism>";
 288 const char *AuthMechLogger::mechStr = "mechanism ";
 289
 290 AuthMechLogger::AuthMechLogger(const AuditToken &srcToken, short auEvent)
 291     : AuditLogger(srcToken, auEvent), RightLogger(),
 292       mEvaluatingMechanism(false), mCurrentMechanism(unknownMechStr)
 293 {
 294 }
 295
 296 AuthMechLogger::AuthMechLogger(const audit_token_t *srcToken, short auEvent)
 297     : AuditLogger(srcToken, auEvent), RightLogger(),
 298       mEvaluatingMechanism(false), mCurrentMechanism(unknownMechStr)
 299 {
 300 }
 301
 302 void
 303 AuthMechLogger::setCurrentMechanism(const char *mech)
 304 {
 305     mCurrentMechanism.clear();
 306     if (NULL == mech)
 307     {
 308         mEvaluatingMechanism = false;
 309     }
 310     else
 311     {
 312         mCurrentMechanism = mech;
 313         mEvaluatingMechanism = true;
 314     }
 315 }
 316
 317 void
 318 AuthMechLogger::writeCommon()
 319 {
 320     writeSubject();
 321     writeToken(au_to_text(mRight.c_str()), "right");
 322     if (true == mEvaluatingMechanism)
 323     {
 324         string tmpStr = mechStr;    // mechStr includes a trailing space
 325         tmpStr += mCurrentMechanism;
 326         writeToken(au_to_text(tmpStr.c_str()), "mechanism");
 327     }
 328 }
 329
 330 void
 331 AuthMechLogger::logInterrupt(const char *msg)
 332 {
 333     if (false == open())
 334         return;
 335     writeCommon();
 336     if (msg)
 337         writeToken(au_to_text(msg), "interrupt");
 338     writeReturn(0, 0);
 339     close();
 340 }
 341
 342 //
 343 // RightAuthenticationLogger
 344 //
 345 const char *RightAuthenticationLogger::unknownUserStr = "<unknown user>";
 346 const char *RightAuthenticationLogger::unknownClientStr = "<unknown client>";
 347 const char *RightAuthenticationLogger::unknownAuthCreatorStr = "<unknown creator>";
 348 const char *RightAuthenticationLogger::authenticatorStr = "known UID ";
 349 const char *RightAuthenticationLogger::clientStr = "client ";
 350 const char *RightAuthenticationLogger::authCreatorStr = "creator ";
 351 const char *RightAuthenticationLogger::authenticatedAsStr = "authenticated as ";
 352 const char *RightAuthenticationLogger::leastPrivStr = "least-privilege";
 353
 354 RightAuthenticationLogger::RightAuthenticationLogger(const AuditToken &srcToken, short auEvent)
 355     : AuditLogger(srcToken, auEvent), RightLogger()
 356 {
 357 }
 358
 359 RightAuthenticationLogger::RightAuthenticationLogger(const audit_token_t *srcToken, short auEvent)
 360     : AuditLogger(srcToken, auEvent), RightLogger()
 361 {
 362 }
 363
 364 void
 365 RightAuthenticationLogger::writeCommon()
 366 {
 367     writeSubject();
 368     writeToken(au_to_text(mRight.c_str()), "right");
 369 }
 370
 371 void
 372 RightAuthenticationLogger::logSuccess(uid_t authenticator, uid_t target, const char *targetName)
 373 {
 374     if (false == open())
 375         return;
 376     writeCommon();
 377
 378     // au_to_arg32() is really meant for auditing syscall arguments;
 379     // we're slightly abusing it to get descriptive strings for free.
 380     writeToken(au_to_arg32(1, authenticatorStr, authenticator), "authenticator");
 381     string tmpStr(authenticatedAsStr);
 382     // targetName shouldn't be NULL on a successful authentication, but allow
 383     // for programmer screwups
 384     tmpStr += targetName ? targetName : unknownUserStr;
 385     writeToken(au_to_arg32(2, tmpStr.c_str(), target), "target");
 386     writeReturn(0, 0);
 387     close();
 388 }
 389
 390 void
 391 RightAuthenticationLogger::logAuthorizationResult(const char *client, const char *authCreator, int errcode)
 392 {
 393     if (false == open())
 394         return;
 395     writeCommon();
 396     string tmpStr(clientStr);
 397     tmpStr += client ? client : unknownClientStr;
 398     writeToken(au_to_text(tmpStr.c_str()), "Authorization client");
 399     tmpStr.clear();
 400     tmpStr = authCreatorStr;
 401     tmpStr += authCreator ? authCreator : unknownAuthCreatorStr;
 402     writeToken(au_to_text(tmpStr.c_str()), "Authorization creator");
 403     if (errAuthorizationSuccess == errcode)
 404         writeReturn(0, 0);
 405     else
 406         writeReturn(EPERM, errcode);
 407     close();
 408 }
 409
 410 void
 411 RightAuthenticationLogger::logLeastPrivilege(uid_t userId, bool isAuthorizingUser)
 412 {
 413     if (false == open())
 414         return;
 415     writeCommon();
 416     writeToken(au_to_text(leastPrivStr), leastPrivStr);
 417     writeReturn(0, 0);
 418     close();
 419 }
 420
 421 void
 422 RightAuthenticationLogger::logFailure(uid_t authenticator, const char *targetName)
 423 {
 424     if (false == open())
 425         return;
 426     writeCommon();
 427     writeToken(au_to_arg32(1, authenticatorStr, authenticator), "authenticator");
 428     if (NULL == targetName)
 429         writeToken(au_to_text(unknownUserStr), "target username");
 430     else
 431         writeToken(au_to_text(targetName), "target username");
 432     // @@@  EAUTH more appropriate, but !defined for _POSIX_C_SOURCE
 433     writeReturn(EPERM, errAuthorizationDenied);
 434     close();
 435 }
 436
 437 }   // namespace Securityd
 438
 439 }   // namespace CommonCriteria
 440
 441 }   // namespace Security