1 /* 2 ** 2003 January 11 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** 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. Embedded 14 ** systems that do not need this facility may omit it by recompiling 15 ** the library with -DSQLITE_OMIT_AUTHORIZATION=1 16 ** 17 ** $Id: auth.c,v 1.30 2009/05/04 01:58:31 drh Exp $ 18 */ 19 #include "sqliteInt.h" 20 21 /* 22 ** All of the code in this file may be omitted by defining a single 23 ** macro. 24 */ 25 #ifndef SQLITE_OMIT_AUTHORIZATION 26 27 /* 28 ** Set or clear the access authorization function. 29 ** 30 ** The access authorization function is be called during the compilation 31 ** phase to verify that the user has read and/or write access permission on 32 ** various fields of the database. The first argument to the auth function 33 ** is a copy of the 3rd argument to this routine. The second argument 34 ** to the auth function is one of these constants: 35 ** 36 ** SQLITE_CREATE_INDEX 37 ** SQLITE_CREATE_TABLE 38 ** SQLITE_CREATE_TEMP_INDEX 39 ** SQLITE_CREATE_TEMP_TABLE 40 ** SQLITE_CREATE_TEMP_TRIGGER 41 ** SQLITE_CREATE_TEMP_VIEW 42 ** SQLITE_CREATE_TRIGGER 43 ** SQLITE_CREATE_VIEW 44 ** SQLITE_DELETE 45 ** SQLITE_DROP_INDEX 46 ** SQLITE_DROP_TABLE 47 ** SQLITE_DROP_TEMP_INDEX 48 ** SQLITE_DROP_TEMP_TABLE 49 ** SQLITE_DROP_TEMP_TRIGGER 50 ** SQLITE_DROP_TEMP_VIEW 51 ** SQLITE_DROP_TRIGGER 52 ** SQLITE_DROP_VIEW 53 ** SQLITE_INSERT 54 ** SQLITE_PRAGMA 55 ** SQLITE_READ 56 ** SQLITE_SELECT 57 ** SQLITE_TRANSACTION 58 ** SQLITE_UPDATE 59 ** 60 ** The third and fourth arguments to the auth function are the name of 61 ** the table and the column that are being accessed. The auth function 62 ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If 63 ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY 64 ** means that the SQL statement will never-run - the sqlite3_exec() call 65 ** will return with an error. SQLITE_IGNORE means that the SQL statement 66 ** should run but attempts to read the specified column will return NULL 67 ** and attempts to write the column will be ignored. 68 ** 69 ** Setting the auth function to NULL disables this hook. The default 70 ** setting of the auth function is NULL. 71 */ 72 int sqlite3_set_authorizer( 73 sqlite3 *db, 74 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 75 void *pArg 76 ){ 77 sqlite3_mutex_enter(db->mutex); 78 db->xAuth = xAuth; 79 db->pAuthArg = pArg; 80 sqlite3ExpirePreparedStatements(db); 81 sqlite3_mutex_leave(db->mutex); 82 return SQLITE_OK; 83 } 84 85 /* 86 ** Write an error message into pParse->zErrMsg that explains that the 87 ** user-supplied authorization function returned an illegal value. 88 */ 89 static void sqliteAuthBadReturnCode(Parse *pParse){ 90 sqlite3ErrorMsg(pParse, "authorizer malfunction"); 91 pParse->rc = SQLITE_ERROR; 92 } 93 94 /* 95 ** The pExpr should be a TK_COLUMN expression. The table referred to 96 ** is in pTabList or else it is the NEW or OLD table of a trigger. 97 ** Check to see if it is OK to read this particular column. 98 ** 99 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 100 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 101 ** then generate an error. 102 */ 103 void sqlite3AuthRead( 104 Parse *pParse, /* The parser context */ 105 Expr *pExpr, /* The expression to check authorization on */ 106 Schema *pSchema, /* The schema of the expression */ 107 SrcList *pTabList /* All table that pExpr might refer to */ 108 ){ 109 sqlite3 *db = pParse->db; 110 int rc; 111 Table *pTab = 0; /* The table being read */ 112 const char *zCol; /* Name of the column of the table */ 113 int iSrc; /* Index in pTabList->a[] of table being read */ 114 const char *zDBase; /* Name of database being accessed */ 115 TriggerStack *pStack; /* The stack of current triggers */ 116 int iDb; /* The index of the database the expression refers to */ 117 118 if( db->xAuth==0 ) return; 119 assert( pExpr->op==TK_COLUMN ); 120 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 121 if( iDb<0 ){ 122 /* An attempt to read a column out of a subquery or other 123 ** temporary table. */ 124 return; 125 } 126 for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){ 127 if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break; 128 } 129 if( pTabList && iSrc<pTabList->nSrc ){ 130 pTab = pTabList->a[iSrc].pTab; 131 }else if( (pStack = pParse->trigStack)!=0 ){ 132 /* This must be an attempt to read the NEW or OLD pseudo-tables 133 ** of a trigger. 134 */ 135 assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx ); 136 pTab = pStack->pTab; 137 } 138 if( pTab==0 ) return; 139 if( pExpr->iColumn>=0 ){ 140 assert( pExpr->iColumn<pTab->nCol ); 141 zCol = pTab->aCol[pExpr->iColumn].zName; 142 }else if( pTab->iPKey>=0 ){ 143 assert( pTab->iPKey<pTab->nCol ); 144 zCol = pTab->aCol[pTab->iPKey].zName; 145 }else{ 146 zCol = "ROWID"; 147 } 148 assert( iDb>=0 && iDb<db->nDb ); 149 zDBase = db->aDb[iDb].zName; 150 rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 151 pParse->zAuthContext); 152 if( rc==SQLITE_IGNORE ){ 153 pExpr->op = TK_NULL; 154 }else if( rc==SQLITE_DENY ){ 155 if( db->nDb>2 || iDb!=0 ){ 156 sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited", 157 zDBase, pTab->zName, zCol); 158 }else{ 159 sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol); 160 } 161 pParse->rc = SQLITE_AUTH; 162 }else if( rc!=SQLITE_OK ){ 163 sqliteAuthBadReturnCode(pParse); 164 } 165 } 166 167 /* 168 ** Do an authorization check using the code and arguments given. Return 169 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 170 ** is returned, then the error count and error message in pParse are 171 ** modified appropriately. 172 */ 173 int sqlite3AuthCheck( 174 Parse *pParse, 175 int code, 176 const char *zArg1, 177 const char *zArg2, 178 const char *zArg3 179 ){ 180 sqlite3 *db = pParse->db; 181 int rc; 182 183 /* Don't do any authorization checks if the database is initialising 184 ** or if the parser is being invoked from within sqlite3_declare_vtab. 185 */ 186 if( db->init.busy || IN_DECLARE_VTAB ){ 187 return SQLITE_OK; 188 } 189 190 if( db->xAuth==0 ){ 191 return SQLITE_OK; 192 } 193 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 194 if( rc==SQLITE_DENY ){ 195 sqlite3ErrorMsg(pParse, "not authorized"); 196 pParse->rc = SQLITE_AUTH; 197 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 198 rc = SQLITE_DENY; 199 sqliteAuthBadReturnCode(pParse); 200 } 201 return rc; 202 } 203 204 /* 205 ** Push an authorization context. After this routine is called, the 206 ** zArg3 argument to authorization callbacks will be zContext until 207 ** popped. Or if pParse==0, this routine is a no-op. 208 */ 209 void sqlite3AuthContextPush( 210 Parse *pParse, 211 AuthContext *pContext, 212 const char *zContext 213 ){ 214 pContext->pParse = pParse; 215 if( pParse ){ 216 pContext->zAuthContext = pParse->zAuthContext; 217 pParse->zAuthContext = zContext; 218 } 219 } 220 221 /* 222 ** Pop an authorization context that was previously pushed 223 ** by sqlite3AuthContextPush 224 */ 225 void sqlite3AuthContextPop(AuthContext *pContext){ 226 if( pContext->pParse ){ 227 pContext->pParse->zAuthContext = pContext->zAuthContext; 228 pContext->pParse = 0; 229 } 230 } 231 232 #endif /* SQLITE_OMIT_AUTHORIZATION */ 233