AryaWu/sqlite
0
1/*2** 2003 January 113**4** The author disclaims copyright to this source code. In place of5** a legal notice, here is a blessing:6**7** May you do good and not evil.8** May you find forgiveness for yourself and forgive others.9** May you share freely, never taking more than you give.10**11*************************************************************************12** This file contains code used to implement the sqlite3_set_authorizer()13** API. This facility is an optional feature of the library. Embedded14** systems that do not need this facility may omit it by recompiling15** the library with -DSQLITE_OMIT_AUTHORIZATION=116*/17#include "sqliteInt.h"18 19/*20** All of the code in this file may be omitted by defining a single21** macro.22*/23#ifndef SQLITE_OMIT_AUTHORIZATION24 25/*26** Set or clear the access authorization function.27**28** The access authorization function is be called during the compilation29** phase to verify that the user has read and/or write access permission on30** various fields of the database. The first argument to the auth function31** is a copy of the 3rd argument to this routine. The second argument32** to the auth function is one of these constants:33**34** SQLITE_CREATE_INDEX35** SQLITE_CREATE_TABLE36** SQLITE_CREATE_TEMP_INDEX37** SQLITE_CREATE_TEMP_TABLE38** SQLITE_CREATE_TEMP_TRIGGER39** SQLITE_CREATE_TEMP_VIEW40** SQLITE_CREATE_TRIGGER41** SQLITE_CREATE_VIEW42** SQLITE_DELETE43** SQLITE_DROP_INDEX44** SQLITE_DROP_TABLE45** SQLITE_DROP_TEMP_INDEX46** SQLITE_DROP_TEMP_TABLE47** SQLITE_DROP_TEMP_TRIGGER48** SQLITE_DROP_TEMP_VIEW49** SQLITE_DROP_TRIGGER50** SQLITE_DROP_VIEW51** SQLITE_INSERT52** SQLITE_PRAGMA53** SQLITE_READ54** SQLITE_SELECT55** SQLITE_TRANSACTION56** SQLITE_UPDATE57**58** The third and fourth arguments to the auth function are the name of59** the table and the column that are being accessed. The auth function60** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If61** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY62** means that the SQL statement will never-run - the sqlite3_exec() call63** will return with an error. SQLITE_IGNORE means that the SQL statement64** should run but attempts to read the specified column will return NULL65** and attempts to write the column will be ignored.66**67** Setting the auth function to NULL disables this hook. The default68** setting of the auth function is NULL.69*/70int sqlite3_set_authorizer(71 sqlite3 *db,72 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),73 void *pArg74){75#ifdef SQLITE_ENABLE_API_ARMOR76 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;77#endif78 sqlite3_mutex_enter(db->mutex);79 db->xAuth = (sqlite3_xauth)xAuth;80 db->pAuthArg = pArg;81 if( db->xAuth ) sqlite3ExpirePreparedStatements(db, 1);82 sqlite3_mutex_leave(db->mutex);83 return SQLITE_OK;84}85 86/*87** Write an error message into pParse->zErrMsg that explains that the88** user-supplied authorization function returned an illegal value.89*/90static void sqliteAuthBadReturnCode(Parse *pParse){91 sqlite3ErrorMsg(pParse, "authorizer malfunction");92 pParse->rc = SQLITE_ERROR;93}94 95/*96** Invoke the authorization callback for permission to read column zCol from97** table zTab in database zDb. This function assumes that an authorization98** callback has been registered (i.e. that sqlite3.xAuth is not NULL).99**100** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed101** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE102** is treated as SQLITE_DENY. In this case an error is left in pParse.103*/104int sqlite3AuthReadCol(105 Parse *pParse, /* The parser context */106 const char *zTab, /* Table name */107 const char *zCol, /* Column name */108 int iDb /* Index of containing database. */109){110 sqlite3 *db = pParse->db; /* Database handle */111 char *zDb = db->aDb[iDb].zDbSName; /* Schema name of attached database */112 int rc; /* Auth callback return code */113 114 if( db->init.busy ) return SQLITE_OK;115 rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext);116 if( rc==SQLITE_DENY ){117 char *z = sqlite3_mprintf("%s.%s", zTab, zCol);118 if( db->nDb>2 || iDb!=0 ) z = sqlite3_mprintf("%s.%z", zDb, z);119 sqlite3ErrorMsg(pParse, "access to %z is prohibited", z);120 pParse->rc = SQLITE_AUTH;121 }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){122 sqliteAuthBadReturnCode(pParse);123 }124 return rc;125}126 127/*128** The pExpr should be a TK_COLUMN expression. The table referred to129** is in pTabList or else it is the NEW or OLD table of a trigger. 130** Check to see if it is OK to read this particular column.131**132** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 133** instruction into a TK_NULL. If the auth function returns SQLITE_DENY,134** then generate an error.135*/136void sqlite3AuthRead(137 Parse *pParse, /* The parser context */138 Expr *pExpr, /* The expression to check authorization on */139 Schema *pSchema, /* The schema of the expression */140 SrcList *pTabList /* All table that pExpr might refer to */141){142 Table *pTab = 0; /* The table being read */143 const char *zCol; /* Name of the column of the table */144 int iSrc; /* Index in pTabList->a[] of table being read */145 int iDb; /* The index of the database the expression refers to */146 int iCol; /* Index of column in table */147 148 assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER );149 assert( !IN_RENAME_OBJECT );150 assert( pParse->db->xAuth!=0 );151 iDb = sqlite3SchemaToIndex(pParse->db, pSchema);152 if( iDb<0 ){153 /* An attempt to read a column out of a subquery or other154 ** temporary table. */155 return;156 }157 158 if( pExpr->op==TK_TRIGGER ){159 pTab = pParse->pTriggerTab;160 }else{161 assert( pTabList );162 for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){163 if( pExpr->iTable==pTabList->a[iSrc].iCursor ){164 pTab = pTabList->a[iSrc].pSTab;165 break;166 }167 }168 }169 iCol = pExpr->iColumn;170 if( pTab==0 ) return;171 172 if( iCol>=0 ){173 assert( iCol<pTab->nCol );174 zCol = pTab->aCol[iCol].zCnName;175 }else if( pTab->iPKey>=0 ){176 assert( pTab->iPKey<pTab->nCol );177 zCol = pTab->aCol[pTab->iPKey].zCnName;178 }else{179 zCol = "ROWID";180 }181 assert( iDb>=0 && iDb<pParse->db->nDb );182 if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){183 pExpr->op = TK_NULL;184 }185}186 187/*188** Do an authorization check using the code and arguments given. Return189** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY190** is returned, then the error count and error message in pParse are191** modified appropriately.192*/193int sqlite3AuthCheck(194 Parse *pParse,195 int code,196 const char *zArg1,197 const char *zArg2,198 const char *zArg3199){200 sqlite3 *db = pParse->db;201 int rc;202 203 /* Don't do any authorization checks if the database is initializing204 ** or if the parser is being invoked from within sqlite3_declare_vtab.205 */206 assert( !IN_RENAME_OBJECT || db->xAuth==0 );207 if( db->xAuth==0 || db->init.busy || IN_SPECIAL_PARSE ){208 return SQLITE_OK;209 }210 211 /* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the212 ** callback are either NULL pointers or zero-terminated strings that213 ** contain additional details about the action to be authorized.214 **215 ** The following testcase() macros show that any of the 3rd through 6th216 ** parameters can be either NULL or a string. */217 testcase( zArg1==0 );218 testcase( zArg2==0 );219 testcase( zArg3==0 );220 testcase( pParse->zAuthContext==0 );221 222 rc = db->xAuth(db->pAuthArg,code,zArg1,zArg2,zArg3,pParse->zAuthContext);223 if( rc==SQLITE_DENY ){224 sqlite3ErrorMsg(pParse, "not authorized");225 pParse->rc = SQLITE_AUTH;226 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){227 rc = SQLITE_DENY;228 sqliteAuthBadReturnCode(pParse);229 }230 return rc;231}232 233/*234** Push an authorization context. After this routine is called, the235** zArg3 argument to authorization callbacks will be zContext until236** popped. Or if pParse==0, this routine is a no-op.237*/238void sqlite3AuthContextPush(239 Parse *pParse,240 AuthContext *pContext, 241 const char *zContext242){243 assert( pParse );244 pContext->pParse = pParse;245 pContext->zAuthContext = pParse->zAuthContext;246 pParse->zAuthContext = zContext;247}248 249/*250** Pop an authorization context that was previously pushed251** by sqlite3AuthContextPush252*/253void sqlite3AuthContextPop(AuthContext *pContext){254 if( pContext->pParse ){255 pContext->pParse->zAuthContext = pContext->zAuthContext;256 pContext->pParse = 0;257 }258}259 260#endif /* SQLITE_OMIT_AUTHORIZATION */261