diff options
Diffstat (limited to 'src/auth.c')
| -rw-r--r-- | src/auth.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/src/auth.c b/src/auth.c new file mode 100644 index 0000000..3a4f73a --- /dev/null +++ b/src/auth.c @@ -0,0 +1,268 @@ +/* +** 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 +){ +#ifdef SQLITE_ENABLE_API_ARMOR + if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; +#endif + sqlite3_mutex_enter(db->mutex); + db->xAuth = (sqlite3_xauth)xAuth; + db->pAuthArg = pArg; + if( db->xAuth ) sqlite3ExpirePreparedStatements(db, 1); + 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].zDbSName; /* Schema name of attached database */ + int rc; /* Auth callback return code */ + + if( db->init.busy ) return SQLITE_OK; + rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext +#ifdef SQLITE_USER_AUTHENTICATION + ,db->auth.zAuthUser +#endif + ); + if( rc==SQLITE_DENY ){ + char *z = sqlite3_mprintf("%s.%s", zTab, zCol); + if( db->nDb>2 || iDb!=0 ) z = sqlite3_mprintf("%s.%z", zDb, z); + sqlite3ErrorMsg(pParse, "access to %z is prohibited", z); + 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 */ +){ + 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 */ + + assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ); + assert( !IN_RENAME_OBJECT ); + assert( pParse->db->xAuth!=0 ); + iDb = sqlite3SchemaToIndex(pParse->db, pSchema); + if( iDb<0 ){ + /* An attempt to read a column out of a subquery or other + ** temporary table. */ + return; + } + + if( pExpr->op==TK_TRIGGER ){ + pTab = pParse->pTriggerTab; + }else{ + assert( pTabList ); + for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){ + if( pExpr->iTable==pTabList->a[iSrc].iCursor ){ + pTab = pTabList->a[iSrc].pTab; + break; + } + } + } + iCol = pExpr->iColumn; + if( pTab==0 ) return; + + if( iCol>=0 ){ + assert( iCol<pTab->nCol ); + zCol = pTab->aCol[iCol].zCnName; + }else if( pTab->iPKey>=0 ){ + assert( pTab->iPKey<pTab->nCol ); + zCol = pTab->aCol[pTab->iPKey].zCnName; + }else{ + zCol = "ROWID"; + } + assert( iDb>=0 && iDb<pParse->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. + */ + assert( !IN_RENAME_OBJECT || db->xAuth==0 ); + if( db->xAuth==0 || db->init.busy || IN_SPECIAL_PARSE ){ + return SQLITE_OK; + } + + /* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the + ** callback are either NULL pointers or zero-terminated strings that + ** contain additional details about the action to be authorized. + ** + ** The following testcase() macros show that any of the 3rd through 6th + ** parameters can be either NULL or a string. */ + testcase( zArg1==0 ); + testcase( zArg2==0 ); + testcase( zArg3==0 ); + testcase( pParse->zAuthContext==0 ); + + rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext +#ifdef SQLITE_USER_AUTHENTICATION + ,db->auth.zAuthUser +#endif + ); + 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 */ |