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 sqlite3_mutex_enter(db->mutex); 76 db->xAuth = xAuth; 77 db->pAuthArg = pArg; 78 sqlite3ExpirePreparedStatements(db); 79 sqlite3_mutex_leave(db->mutex); 80 return SQLITE_OK; 81 } 82 83 /* 84 ** Write an error message into pParse->zErrMsg that explains that the 85 ** user-supplied authorization function returned an illegal value. 86 */ 87 static void sqliteAuthBadReturnCode(Parse *pParse){ 88 sqlite3ErrorMsg(pParse, "authorizer malfunction"); 89 pParse->rc = SQLITE_ERROR; 90 } 91 92 /* 93 ** Invoke the authorization callback for permission to read column zCol from 94 ** table zTab in database zDb. This function assumes that an authorization 95 ** callback has been registered (i.e. that sqlite3.xAuth is not NULL). 96 ** 97 ** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed 98 ** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE 99 ** is treated as SQLITE_DENY. In this case an error is left in pParse. 100 */ 101 int sqlite3AuthReadCol( 102 Parse *pParse, /* The parser context */ 103 const char *zTab, /* Table name */ 104 const char *zCol, /* Column name */ 105 int iDb /* Index of containing database. */ 106 ){ 107 sqlite3 *db = pParse->db; /* Database handle */ 108 char *zDb = db->aDb[iDb].zName; /* Name of attached database */ 109 int rc; /* Auth callback return code */ 110 111 rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext); 112 if( rc==SQLITE_DENY ){ 113 if( db->nDb>2 || iDb!=0 ){ 114 sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol); 115 }else{ 116 sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited", zTab, zCol); 117 } 118 pParse->rc = SQLITE_AUTH; 119 }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){ 120 sqliteAuthBadReturnCode(pParse); 121 } 122 return rc; 123 } 124 125 /* 126 ** The pExpr should be a TK_COLUMN expression. The table referred to 127 ** is in pTabList or else it is the NEW or OLD table of a trigger. 128 ** Check to see if it is OK to read this particular column. 129 ** 130 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 131 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 132 ** then generate an error. 133 */ 134 void sqlite3AuthRead( 135 Parse *pParse, /* The parser context */ 136 Expr *pExpr, /* The expression to check authorization on */ 137 Schema *pSchema, /* The schema of the expression */ 138 SrcList *pTabList /* All table that pExpr might refer to */ 139 ){ 140 sqlite3 *db = pParse->db; 141 Table *pTab = 0; /* The table being read */ 142 const char *zCol; /* Name of the column of the table */ 143 int iSrc; /* Index in pTabList->a[] of table being read */ 144 int iDb; /* The index of the database the expression refers to */ 145 int iCol; /* Index of column in table */ 146 147 if( db->xAuth==0 ) return; 148 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 149 if( iDb<0 ){ 150 /* An attempt to read a column out of a subquery or other 151 ** temporary table. */ 152 return; 153 } 154 155 assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ); 156 if( pExpr->op==TK_TRIGGER ){ 157 pTab = pParse->pTriggerTab; 158 }else{ 159 assert( pTabList ); 160 for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){ 161 if( pExpr->iTable==pTabList->a[iSrc].iCursor ){ 162 pTab = pTabList->a[iSrc].pTab; 163 break; 164 } 165 } 166 } 167 iCol = pExpr->iColumn; 168 if( NEVER(pTab==0) ) return; 169 170 if( iCol>=0 ){ 171 assert( iCol<pTab->nCol ); 172 zCol = pTab->aCol[iCol].zName; 173 }else if( pTab->iPKey>=0 ){ 174 assert( pTab->iPKey<pTab->nCol ); 175 zCol = pTab->aCol[pTab->iPKey].zName; 176 }else{ 177 zCol = "ROWID"; 178 } 179 assert( iDb>=0 && iDb<db->nDb ); 180 if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){ 181 pExpr->op = TK_NULL; 182 } 183 } 184 185 /* 186 ** Do an authorization check using the code and arguments given. Return 187 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 188 ** is returned, then the error count and error message in pParse are 189 ** modified appropriately. 190 */ 191 int sqlite3AuthCheck( 192 Parse *pParse, 193 int code, 194 const char *zArg1, 195 const char *zArg2, 196 const char *zArg3 197 ){ 198 sqlite3 *db = pParse->db; 199 int rc; 200 201 /* Don't do any authorization checks if the database is initialising 202 ** or if the parser is being invoked from within sqlite3_declare_vtab. 203 */ 204 if( db->init.busy || IN_DECLARE_VTAB ){ 205 return SQLITE_OK; 206 } 207 208 if( db->xAuth==0 ){ 209 return SQLITE_OK; 210 } 211 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 212 if( rc==SQLITE_DENY ){ 213 sqlite3ErrorMsg(pParse, "not authorized"); 214 pParse->rc = SQLITE_AUTH; 215 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 216 rc = SQLITE_DENY; 217 sqliteAuthBadReturnCode(pParse); 218 } 219 return rc; 220 } 221 222 /* 223 ** Push an authorization context. After this routine is called, the 224 ** zArg3 argument to authorization callbacks will be zContext until 225 ** popped. Or if pParse==0, this routine is a no-op. 226 */ 227 void sqlite3AuthContextPush( 228 Parse *pParse, 229 AuthContext *pContext, 230 const char *zContext 231 ){ 232 assert( pParse ); 233 pContext->pParse = pParse; 234 pContext->zAuthContext = pParse->zAuthContext; 235 pParse->zAuthContext = zContext; 236 } 237 238 /* 239 ** Pop an authorization context that was previously pushed 240 ** by sqlite3AuthContextPush 241 */ 242 void sqlite3AuthContextPop(AuthContext *pContext){ 243 if( pContext->pParse ){ 244 pContext->pParse->zAuthContext = pContext->zAuthContext; 245 pContext->pParse = 0; 246 } 247 } 248 249 #endif /* SQLITE_OMIT_AUTHORIZATION */ 250
