--HG-- extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%401209
		
			
				
	
	
		
			234 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			234 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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| ** 2003 January 11
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| **
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| ** The author disclaims copyright to this source code.  In place of
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| ** a legal notice, here is a blessing:
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| **
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| **    May you do good and not evil.
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| **    May you find forgiveness for yourself and forgive others.
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| **    May you share freely, never taking more than you give.
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| **
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| *************************************************************************
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| ** This file contains code used to implement the sqlite3_set_authorizer()
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| ** API.  This facility is an optional feature of the library.  Embedded
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| ** systems that do not need this facility may omit it by recompiling
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| ** the library with -DSQLITE_OMIT_AUTHORIZATION=1
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| **
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| ** $Id$
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| */
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| #include "sqliteInt.h"
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| 
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| /*
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| ** All of the code in this file may be omitted by defining a single
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| ** macro.
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| */
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| #ifndef SQLITE_OMIT_AUTHORIZATION
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| 
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| /*
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| ** Set or clear the access authorization function.
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| **
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| ** The access authorization function is be called during the compilation
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| ** phase to verify that the user has read and/or write access permission on
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| ** various fields of the database.  The first argument to the auth function
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| ** is a copy of the 3rd argument to this routine.  The second argument
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| ** to the auth function is one of these constants:
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| **
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| **       SQLITE_CREATE_INDEX
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| **       SQLITE_CREATE_TABLE
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| **       SQLITE_CREATE_TEMP_INDEX
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| **       SQLITE_CREATE_TEMP_TABLE
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| **       SQLITE_CREATE_TEMP_TRIGGER
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| **       SQLITE_CREATE_TEMP_VIEW
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| **       SQLITE_CREATE_TRIGGER
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| **       SQLITE_CREATE_VIEW
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| **       SQLITE_DELETE
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| **       SQLITE_DROP_INDEX
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| **       SQLITE_DROP_TABLE
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| **       SQLITE_DROP_TEMP_INDEX
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| **       SQLITE_DROP_TEMP_TABLE
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| **       SQLITE_DROP_TEMP_TRIGGER
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| **       SQLITE_DROP_TEMP_VIEW
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| **       SQLITE_DROP_TRIGGER
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| **       SQLITE_DROP_VIEW
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| **       SQLITE_INSERT
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| **       SQLITE_PRAGMA
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| **       SQLITE_READ
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| **       SQLITE_SELECT
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| **       SQLITE_TRANSACTION
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| **       SQLITE_UPDATE
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| **
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| ** The third and fourth arguments to the auth function are the name of
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| ** the table and the column that are being accessed.  The auth function
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| ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  If
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| ** SQLITE_OK is returned, it means that access is allowed.  SQLITE_DENY
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| ** means that the SQL statement will never-run - the sqlite3_exec() call
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| ** will return with an error.  SQLITE_IGNORE means that the SQL statement
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| ** should run but attempts to read the specified column will return NULL
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| ** and attempts to write the column will be ignored.
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| **
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| ** Setting the auth function to NULL disables this hook.  The default
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| ** setting of the auth function is NULL.
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| */
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| int sqlite3_set_authorizer(
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|   sqlite3 *db,
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|   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
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|   void *pArg
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| ){
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|   db->xAuth = xAuth;
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|   db->pAuthArg = pArg;
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|   sqlite3ExpirePreparedStatements(db);
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|   return SQLITE_OK;
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| }
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| 
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| /*
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| ** Write an error message into pParse->zErrMsg that explains that the
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| ** user-supplied authorization function returned an illegal value.
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| */
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| static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
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|   sqlite3ErrorMsg(pParse, "illegal return value (%d) from the "
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|     "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
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|     "or SQLITE_DENY", rc);
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|   pParse->rc = SQLITE_ERROR;
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| }
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| 
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| /*
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| ** The pExpr should be a TK_COLUMN expression.  The table referred to
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| ** is in pTabList or else it is the NEW or OLD table of a trigger.  
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| ** Check to see if it is OK to read this particular column.
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| **
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| ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 
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| ** instruction into a TK_NULL.  If the auth function returns SQLITE_DENY,
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| ** then generate an error.
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| */
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| void sqlite3AuthRead(
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|   Parse *pParse,        /* The parser context */
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|   Expr *pExpr,          /* The expression to check authorization on */
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|   SrcList *pTabList     /* All table that pExpr might refer to */
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| ){
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|   sqlite3 *db = pParse->db;
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|   int rc;
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|   Table *pTab;          /* The table being read */
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|   const char *zCol;     /* Name of the column of the table */
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|   int iSrc;             /* Index in pTabList->a[] of table being read */
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|   const char *zDBase;   /* Name of database being accessed */
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|   TriggerStack *pStack; /* The stack of current triggers */
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|   int iDb;              /* The index of the database the expression refers to */
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| 
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|   if( db->xAuth==0 ) return;
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|   if( pExpr->op!=TK_COLUMN ) return;
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|   iDb = sqlite3SchemaToIndex(pParse->db, pExpr->pSchema);
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|   if( iDb<0 ){
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|     /* An attempt to read a column out of a subquery or other
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|     ** temporary table. */
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|     return;
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|   }
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|   for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){
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|     if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
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|   }
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|   if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){
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|     pTab = pTabList->a[iSrc].pTab;
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|   }else if( (pStack = pParse->trigStack)!=0 ){
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|     /* This must be an attempt to read the NEW or OLD pseudo-tables
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|     ** of a trigger.
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|     */
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|     assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
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|     pTab = pStack->pTab;
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|   }else{
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|     return;
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|   }
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|   if( pTab==0 ) return;
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|   if( pExpr->iColumn>=0 ){
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|     assert( pExpr->iColumn<pTab->nCol );
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|     zCol = pTab->aCol[pExpr->iColumn].zName;
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|   }else if( pTab->iPKey>=0 ){
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|     assert( pTab->iPKey<pTab->nCol );
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|     zCol = pTab->aCol[pTab->iPKey].zName;
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|   }else{
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|     zCol = "ROWID";
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|   }
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|   assert( iDb>=0 && iDb<db->nDb );
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|   zDBase = db->aDb[iDb].zName;
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|   rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 
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|                  pParse->zAuthContext);
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|   if( rc==SQLITE_IGNORE ){
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|     pExpr->op = TK_NULL;
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|   }else if( rc==SQLITE_DENY ){
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|     if( db->nDb>2 || iDb!=0 ){
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|       sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited", 
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|          zDBase, pTab->zName, zCol);
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|     }else{
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|       sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol);
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|     }
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|     pParse->rc = SQLITE_AUTH;
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|   }else if( rc!=SQLITE_OK ){
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|     sqliteAuthBadReturnCode(pParse, rc);
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|   }
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| }
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| 
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| /*
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| ** Do an authorization check using the code and arguments given.  Return
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| ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY.  If SQLITE_DENY
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| ** is returned, then the error count and error message in pParse are
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| ** modified appropriately.
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| */
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| int sqlite3AuthCheck(
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|   Parse *pParse,
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|   int code,
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|   const char *zArg1,
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|   const char *zArg2,
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|   const char *zArg3
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| ){
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|   sqlite3 *db = pParse->db;
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|   int rc;
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| 
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|   /* Don't do any authorization checks if the database is initialising
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|   ** or if the parser is being invoked from within sqlite3_declare_vtab.
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|   */
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|   if( db->init.busy || IN_DECLARE_VTAB ){
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|     return SQLITE_OK;
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|   }
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| 
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|   if( db->xAuth==0 ){
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|     return SQLITE_OK;
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|   }
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|   rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
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|   if( rc==SQLITE_DENY ){
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|     sqlite3ErrorMsg(pParse, "not authorized");
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|     pParse->rc = SQLITE_AUTH;
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|   }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
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|     rc = SQLITE_DENY;
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|     sqliteAuthBadReturnCode(pParse, rc);
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|   }
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|   return rc;
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| }
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| 
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| /*
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| ** Push an authorization context.  After this routine is called, the
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| ** zArg3 argument to authorization callbacks will be zContext until
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| ** popped.  Or if pParse==0, this routine is a no-op.
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| */
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| void sqlite3AuthContextPush(
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|   Parse *pParse,
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|   AuthContext *pContext, 
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|   const char *zContext
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| ){
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|   pContext->pParse = pParse;
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|   if( pParse ){
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|     pContext->zAuthContext = pParse->zAuthContext;
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|     pParse->zAuthContext = zContext;
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|   }
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| }
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| 
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| /*
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| ** Pop an authorization context that was previously pushed
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| ** by sqlite3AuthContextPush
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| */
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| void sqlite3AuthContextPop(AuthContext *pContext){
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|   if( pContext->pParse ){
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|     pContext->pParse->zAuthContext = pContext->zAuthContext;
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|     pContext->pParse = 0;
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|   }
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| }
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| 
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| #endif /* SQLITE_OMIT_AUTHORIZATION */
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