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].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 #ifdef SQLITE_USER_AUTHENTICATION 117 ,db->auth.zAuthUser 118 #endif 119 ); 120 if( rc==SQLITE_DENY ){ 121 if( db->nDb>2 || iDb!=0 ){ 122 sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol); 123 }else{ 124 sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited", zTab, zCol); 125 } 126 pParse->rc = SQLITE_AUTH; 127 }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){ 128 sqliteAuthBadReturnCode(pParse); 129 } 130 return rc; 131 } 132 133 /* 134 ** The pExpr should be a TK_COLUMN expression. The table referred to 135 ** is in pTabList or else it is the NEW or OLD table of a trigger. 136 ** Check to see if it is OK to read this particular column. 137 ** 138 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 139 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 140 ** then generate an error. 141 */ 142 void sqlite3AuthRead( 143 Parse *pParse, /* The parser context */ 144 Expr *pExpr, /* The expression to check authorization on */ 145 Schema *pSchema, /* The schema of the expression */ 146 SrcList *pTabList /* All table that pExpr might refer to */ 147 ){ 148 sqlite3 *db = pParse->db; 149 Table *pTab = 0; /* The table being read */ 150 const char *zCol; /* Name of the column of the table */ 151 int iSrc; /* Index in pTabList->a[] of table being read */ 152 int iDb; /* The index of the database the expression refers to */ 153 int iCol; /* Index of column in table */ 154 155 if( db->xAuth==0 ) return; 156 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 157 if( iDb<0 ){ 158 /* An attempt to read a column out of a subquery or other 159 ** temporary table. */ 160 return; 161 } 162 163 assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ); 164 if( pExpr->op==TK_TRIGGER ){ 165 pTab = pParse->pTriggerTab; 166 }else{ 167 assert( pTabList ); 168 for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){ 169 if( pExpr->iTable==pTabList->a[iSrc].iCursor ){ 170 pTab = pTabList->a[iSrc].pTab; 171 break; 172 } 173 } 174 } 175 iCol = pExpr->iColumn; 176 if( NEVER(pTab==0) ) return; 177 178 if( iCol>=0 ){ 179 assert( iCol<pTab->nCol ); 180 zCol = pTab->aCol[iCol].zName; 181 }else if( pTab->iPKey>=0 ){ 182 assert( pTab->iPKey<pTab->nCol ); 183 zCol = pTab->aCol[pTab->iPKey].zName; 184 }else{ 185 zCol = "ROWID"; 186 } 187 assert( iDb>=0 && iDb<db->nDb ); 188 if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){ 189 pExpr->op = TK_NULL; 190 } 191 } 192 193 /* 194 ** Do an authorization check using the code and arguments given. Return 195 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 196 ** is returned, then the error count and error message in pParse are 197 ** modified appropriately. 198 */ 199 int sqlite3AuthCheck( 200 Parse *pParse, 201 int code, 202 const char *zArg1, 203 const char *zArg2, 204 const char *zArg3 205 ){ 206 sqlite3 *db = pParse->db; 207 int rc; 208 209 /* Don't do any authorization checks if the database is initialising 210 ** or if the parser is being invoked from within sqlite3_declare_vtab. 211 */ 212 if( db->init.busy || IN_DECLARE_VTAB ){ 213 return SQLITE_OK; 214 } 215 216 if( db->xAuth==0 ){ 217 return SQLITE_OK; 218 } 219 220 /* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the 221 ** callback are either NULL pointers or zero-terminated strings that 222 ** contain additional details about the action to be authorized. 223 ** 224 ** The following testcase() macros show that any of the 3rd through 6th 225 ** parameters can be either NULL or a string. */ 226 testcase( zArg1==0 ); 227 testcase( zArg2==0 ); 228 testcase( zArg3==0 ); 229 testcase( pParse->zAuthContext==0 ); 230 231 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext 232 #ifdef SQLITE_USER_AUTHENTICATION 233 ,db->auth.zAuthUser 234 #endif 235 ); 236 if( rc==SQLITE_DENY ){ 237 sqlite3ErrorMsg(pParse, "not authorized"); 238 pParse->rc = SQLITE_AUTH; 239 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 240 rc = SQLITE_DENY; 241 sqliteAuthBadReturnCode(pParse); 242 } 243 return rc; 244 } 245 246 /* 247 ** Push an authorization context. After this routine is called, the 248 ** zArg3 argument to authorization callbacks will be zContext until 249 ** popped. Or if pParse==0, this routine is a no-op. 250 */ 251 void sqlite3AuthContextPush( 252 Parse *pParse, 253 AuthContext *pContext, 254 const char *zContext 255 ){ 256 assert( pParse ); 257 pContext->pParse = pParse; 258 pContext->zAuthContext = pParse->zAuthContext; 259 pParse->zAuthContext = zContext; 260 } 261 262 /* 263 ** Pop an authorization context that was previously pushed 264 ** by sqlite3AuthContextPush 265 */ 266 void sqlite3AuthContextPop(AuthContext *pContext){ 267 if( pContext->pParse ){ 268 pContext->pParse->zAuthContext = pContext->zAuthContext; 269 pContext->pParse = 0; 270 } 271 } 272 273 #endif /* SQLITE_OMIT_AUTHORIZATION */ 274