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 #include "sqliteInt.h" 18 19 /* 20 ** All of the code in this file may be omitted by defining a single 21 ** macro. 22 */ 23 #ifndef SQLITE_OMIT_AUTHORIZATION 24 25 /* 26 ** Set or clear the access authorization function. 27 ** 28 ** The access authorization function is be called during the compilation 29 ** phase to verify that the user has read and/or write access permission on 30 ** various fields of the database. The first argument to the auth function 31 ** is a copy of the 3rd argument to this routine. The second argument 32 ** to the auth function is one of these constants: 33 ** 34 ** SQLITE_CREATE_INDEX 35 ** SQLITE_CREATE_TABLE 36 ** SQLITE_CREATE_TEMP_INDEX 37 ** SQLITE_CREATE_TEMP_TABLE 38 ** SQLITE_CREATE_TEMP_TRIGGER 39 ** SQLITE_CREATE_TEMP_VIEW 40 ** SQLITE_CREATE_TRIGGER 41 ** SQLITE_CREATE_VIEW 42 ** SQLITE_DELETE 43 ** SQLITE_DROP_INDEX 44 ** SQLITE_DROP_TABLE 45 ** SQLITE_DROP_TEMP_INDEX 46 ** SQLITE_DROP_TEMP_TABLE 47 ** SQLITE_DROP_TEMP_TRIGGER 48 ** SQLITE_DROP_TEMP_VIEW 49 ** SQLITE_DROP_TRIGGER 50 ** SQLITE_DROP_VIEW 51 ** SQLITE_INSERT 52 ** SQLITE_PRAGMA 53 ** SQLITE_READ 54 ** SQLITE_SELECT 55 ** SQLITE_TRANSACTION 56 ** SQLITE_UPDATE 57 ** 58 ** The third and fourth arguments to the auth function are the name of 59 ** the table and the column that are being accessed. The auth function 60 ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If 61 ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY 62 ** means that the SQL statement will never-run - the sqlite3_exec() call 63 ** will return with an error. SQLITE_IGNORE means that the SQL statement 64 ** should run but attempts to read the specified column will return NULL 65 ** and attempts to write the column will be ignored. 66 ** 67 ** Setting the auth function to NULL disables this hook. The default 68 ** setting of the auth function is NULL. 69 */ 70 int sqlite3_set_authorizer( 71 sqlite3 *db, 72 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 73 void *pArg 74 ){ 75 #ifdef SQLITE_ENABLE_API_ARMOR 76 if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT; 77 #endif 78 sqlite3_mutex_enter(db->mutex); 79 db->xAuth = (sqlite3_xauth)xAuth; 80 db->pAuthArg = pArg; 81 sqlite3ExpirePreparedStatements(db); 82 sqlite3_mutex_leave(db->mutex); 83 return SQLITE_OK; 84 } 85 86 /* 87 ** Write an error message into pParse->zErrMsg that explains that the 88 ** user-supplied authorization function returned an illegal value. 89 */ 90 static 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 from 97 ** table zTab in database zDb. This function assumes that an authorization 98 ** 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 changed 101 ** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE 102 ** is treated as SQLITE_DENY. In this case an error is left in pParse. 103 */ 104 int 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].zName; /* Name of attached database */ 112 int rc; /* Auth callback return code */ 113 114 rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext 115 #ifdef SQLITE_USER_AUTHENTICATION 116 ,db->auth.zAuthUser 117 #endif 118 ); 119 if( rc==SQLITE_DENY ){ 120 if( db->nDb>2 || iDb!=0 ){ 121 sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol); 122 }else{ 123 sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited", zTab, zCol); 124 } 125 pParse->rc = SQLITE_AUTH; 126 }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){ 127 sqliteAuthBadReturnCode(pParse); 128 } 129 return rc; 130 } 131 132 /* 133 ** The pExpr should be a TK_COLUMN expression. The table referred to 134 ** is in pTabList or else it is the NEW or OLD table of a trigger. 135 ** Check to see if it is OK to read this particular column. 136 ** 137 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 138 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 139 ** then generate an error. 140 */ 141 void sqlite3AuthRead( 142 Parse *pParse, /* The parser context */ 143 Expr *pExpr, /* The expression to check authorization on */ 144 Schema *pSchema, /* The schema of the expression */ 145 SrcList *pTabList /* All table that pExpr might refer to */ 146 ){ 147 sqlite3 *db = pParse->db; 148 Table *pTab = 0; /* The table being read */ 149 const char *zCol; /* Name of the column of the table */ 150 int iSrc; /* Index in pTabList->a[] of table being read */ 151 int iDb; /* The index of the database the expression refers to */ 152 int iCol; /* Index of column in table */ 153 154 if( db->xAuth==0 ) return; 155 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 156 if( iDb<0 ){ 157 /* An attempt to read a column out of a subquery or other 158 ** temporary table. */ 159 return; 160 } 161 162 assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ); 163 if( pExpr->op==TK_TRIGGER ){ 164 pTab = pParse->pTriggerTab; 165 }else{ 166 assert( pTabList ); 167 for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){ 168 if( pExpr->iTable==pTabList->a[iSrc].iCursor ){ 169 pTab = pTabList->a[iSrc].pTab; 170 break; 171 } 172 } 173 } 174 iCol = pExpr->iColumn; 175 if( NEVER(pTab==0) ) return; 176 177 if( iCol>=0 ){ 178 assert( iCol<pTab->nCol ); 179 zCol = pTab->aCol[iCol].zName; 180 }else if( pTab->iPKey>=0 ){ 181 assert( pTab->iPKey<pTab->nCol ); 182 zCol = pTab->aCol[pTab->iPKey].zName; 183 }else{ 184 zCol = "ROWID"; 185 } 186 assert( iDb>=0 && iDb<db->nDb ); 187 if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){ 188 pExpr->op = TK_NULL; 189 } 190 } 191 192 /* 193 ** Do an authorization check using the code and arguments given. Return 194 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 195 ** is returned, then the error count and error message in pParse are 196 ** modified appropriately. 197 */ 198 int sqlite3AuthCheck( 199 Parse *pParse, 200 int code, 201 const char *zArg1, 202 const char *zArg2, 203 const char *zArg3 204 ){ 205 sqlite3 *db = pParse->db; 206 int rc; 207 208 /* Don't do any authorization checks if the database is initialising 209 ** or if the parser is being invoked from within sqlite3_declare_vtab. 210 */ 211 if( db->init.busy || IN_DECLARE_VTAB ){ 212 return SQLITE_OK; 213 } 214 215 if( db->xAuth==0 ){ 216 return SQLITE_OK; 217 } 218 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext 219 #ifdef SQLITE_USER_AUTHENTICATION 220 ,db->auth.zAuthUser 221 #endif 222 ); 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, the 235 ** zArg3 argument to authorization callbacks will be zContext until 236 ** popped. Or if pParse==0, this routine is a no-op. 237 */ 238 void sqlite3AuthContextPush( 239 Parse *pParse, 240 AuthContext *pContext, 241 const char *zContext 242 ){ 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 pushed 251 ** by sqlite3AuthContextPush 252 */ 253 void 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