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- /*
- ** 2003 January 11
- **
- ** The author disclaims copyright to this source code. In place of
- ** a legal notice, here is a blessing:
- **
- ** May you do good and not evil.
- ** May you find forgiveness for yourself and forgive others.
- ** May you share freely, never taking more than you give.
- **
- *************************************************************************
- ** This file contains code used to implement the sqlite3_set_authorizer()
- ** API. This facility is an optional feature of the library. Embedded
- ** systems that do not need this facility may omit it by recompiling
- ** the library with -DSQLITE_OMIT_AUTHORIZATION=1
- */
- #include "sqliteInt.h"
- /*
- ** All of the code in this file may be omitted by defining a single
- ** macro.
- */
- #ifndef SQLITE_OMIT_AUTHORIZATION
- /*
- ** Set or clear the access authorization function.
- **
- ** The access authorization function is be called during the compilation
- ** phase to verify that the user has read and/or write access permission on
- ** various fields of the database. The first argument to the auth function
- ** is a copy of the 3rd argument to this routine. The second argument
- ** to the auth function is one of these constants:
- **
- ** SQLITE_CREATE_INDEX
- ** SQLITE_CREATE_TABLE
- ** SQLITE_CREATE_TEMP_INDEX
- ** SQLITE_CREATE_TEMP_TABLE
- ** SQLITE_CREATE_TEMP_TRIGGER
- ** SQLITE_CREATE_TEMP_VIEW
- ** SQLITE_CREATE_TRIGGER
- ** SQLITE_CREATE_VIEW
- ** SQLITE_DELETE
- ** SQLITE_DROP_INDEX
- ** SQLITE_DROP_TABLE
- ** SQLITE_DROP_TEMP_INDEX
- ** SQLITE_DROP_TEMP_TABLE
- ** SQLITE_DROP_TEMP_TRIGGER
- ** SQLITE_DROP_TEMP_VIEW
- ** SQLITE_DROP_TRIGGER
- ** SQLITE_DROP_VIEW
- ** SQLITE_INSERT
- ** SQLITE_PRAGMA
- ** SQLITE_READ
- ** SQLITE_SELECT
- ** SQLITE_TRANSACTION
- ** SQLITE_UPDATE
- **
- ** The third and fourth arguments to the auth function are the name of
- ** the table and the column that are being accessed. The auth function
- ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If
- ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY
- ** means that the SQL statement will never-run - the sqlite3_exec() call
- ** will return with an error. SQLITE_IGNORE means that the SQL statement
- ** should run but attempts to read the specified column will return NULL
- ** and attempts to write the column will be ignored.
- **
- ** Setting the auth function to NULL disables this hook. The default
- ** setting of the auth function is NULL.
- */
- int sqlite3_set_authorizer(
- sqlite3 *db,
- int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
- void *pArg
- ){
- sqlite3_mutex_enter(db->mutex);
- db->xAuth = xAuth;
- db->pAuthArg = pArg;
- sqlite3ExpirePreparedStatements(db);
- sqlite3_mutex_leave(db->mutex);
- return SQLITE_OK;
- }
- /*
- ** Write an error message into pParse->zErrMsg that explains that the
- ** user-supplied authorization function returned an illegal value.
- */
- static void sqliteAuthBadReturnCode(Parse *pParse){
- sqlite3ErrorMsg(pParse, "authorizer malfunction");
- pParse->rc = SQLITE_ERROR;
- }
- /*
- ** Invoke the authorization callback for permission to read column zCol from
- ** table zTab in database zDb. This function assumes that an authorization
- ** callback has been registered (i.e. that sqlite3.xAuth is not NULL).
- **
- ** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed
- ** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE
- ** is treated as SQLITE_DENY. In this case an error is left in pParse.
- */
- int sqlite3AuthReadCol(
- Parse *pParse, /* The parser context */
- const char *zTab, /* Table name */
- const char *zCol, /* Column name */
- int iDb /* Index of containing database. */
- ){
- sqlite3 *db = pParse->db; /* Database handle */
- char *zDb = db->aDb[iDb].zName; /* Name of attached database */
- int rc; /* Auth callback return code */
- rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext);
- if( rc==SQLITE_DENY ){
- if( db->nDb>2 || iDb!=0 ){
- sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol);
- }else{
- sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited", zTab, zCol);
- }
- pParse->rc = SQLITE_AUTH;
- }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){
- sqliteAuthBadReturnCode(pParse);
- }
- return rc;
- }
- /*
- ** The pExpr should be a TK_COLUMN expression. The table referred to
- ** is in pTabList or else it is the NEW or OLD table of a trigger.
- ** Check to see if it is OK to read this particular column.
- **
- ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN
- ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY,
- ** then generate an error.
- */
- void sqlite3AuthRead(
- Parse *pParse, /* The parser context */
- Expr *pExpr, /* The expression to check authorization on */
- Schema *pSchema, /* The schema of the expression */
- SrcList *pTabList /* All table that pExpr might refer to */
- ){
- sqlite3 *db = pParse->db;
- Table *pTab = 0; /* The table being read */
- const char *zCol; /* Name of the column of the table */
- int iSrc; /* Index in pTabList->a[] of table being read */
- int iDb; /* The index of the database the expression refers to */
- int iCol; /* Index of column in table */
- if( db->xAuth==0 ) return;
- iDb = sqlite3SchemaToIndex(pParse->db, pSchema);
- if( iDb<0 ){
- /* An attempt to read a column out of a subquery or other
- ** temporary table. */
- return;
- }
- assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER );
- if( pExpr->op==TK_TRIGGER ){
- pTab = pParse->pTriggerTab;
- }else{
- assert( pTabList );
- for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){
- if( pExpr->iTable==pTabList->a[iSrc].iCursor ){
- pTab = pTabList->a[iSrc].pTab;
- break;
- }
- }
- }
- iCol = pExpr->iColumn;
- if( NEVER(pTab==0) ) return;
- if( iCol>=0 ){
- assert( iCol<pTab->nCol );
- zCol = pTab->aCol[iCol].zName;
- }else if( pTab->iPKey>=0 ){
- assert( pTab->iPKey<pTab->nCol );
- zCol = pTab->aCol[pTab->iPKey].zName;
- }else{
- zCol = "ROWID";
- }
- assert( iDb>=0 && iDb<db->nDb );
- if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){
- pExpr->op = TK_NULL;
- }
- }
- /*
- ** Do an authorization check using the code and arguments given. Return
- ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY
- ** is returned, then the error count and error message in pParse are
- ** modified appropriately.
- */
- int sqlite3AuthCheck(
- Parse *pParse,
- int code,
- const char *zArg1,
- const char *zArg2,
- const char *zArg3
- ){
- sqlite3 *db = pParse->db;
- int rc;
- /* Don't do any authorization checks if the database is initialising
- ** or if the parser is being invoked from within sqlite3_declare_vtab.
- */
- if( db->init.busy || IN_DECLARE_VTAB ){
- return SQLITE_OK;
- }
- if( db->xAuth==0 ){
- return SQLITE_OK;
- }
- rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
- if( rc==SQLITE_DENY ){
- sqlite3ErrorMsg(pParse, "not authorized");
- pParse->rc = SQLITE_AUTH;
- }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
- rc = SQLITE_DENY;
- sqliteAuthBadReturnCode(pParse);
- }
- return rc;
- }
- /*
- ** Push an authorization context. After this routine is called, the
- ** zArg3 argument to authorization callbacks will be zContext until
- ** popped. Or if pParse==0, this routine is a no-op.
- */
- void sqlite3AuthContextPush(
- Parse *pParse,
- AuthContext *pContext,
- const char *zContext
- ){
- assert( pParse );
- pContext->pParse = pParse;
- pContext->zAuthContext = pParse->zAuthContext;
- pParse->zAuthContext = zContext;
- }
- /*
- ** Pop an authorization context that was previously pushed
- ** by sqlite3AuthContextPush
- */
- void sqlite3AuthContextPop(AuthContext *pContext){
- if( pContext->pParse ){
- pContext->pParse->zAuthContext = pContext->zAuthContext;
- pContext->pParse = 0;
- }
- }
- #endif /* SQLITE_OMIT_AUTHORIZATION */
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