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 1.32 2009/07/02 18:40:35 danielk1977 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 ** Invoke the authorization callback for permission to read column zCol from 96 ** table zTab in database zDb. This function assumes that an authorization 97 ** callback has been registered (i.e. that sqlite3.xAuth is not NULL). 98 ** 99 ** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed 100 ** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE 101 ** is treated as SQLITE_DENY. In this case an error is left in pParse. 102 */ 103 int sqlite3AuthReadCol( 104 Parse *pParse, /* The parser context */ 105 const char *zTab, /* Table name */ 106 const char *zCol, /* Column name */ 107 int iDb /* Index of containing database. */ 108 ){ 109 sqlite3 *db = pParse->db; /* Database handle */ 110 char *zDb = db->aDb[iDb].zName; /* Name of attached database */ 111 int rc; /* Auth callback return code */ 112 113 rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext); 114 if( rc==SQLITE_DENY ){ 115 if( db->nDb>2 || iDb!=0 ){ 116 sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol); 117 }else{ 118 sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited", zTab, zCol); 119 } 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 to 129 ** 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 */ 136 void 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 sqlite3 *db = pParse->db; 143 Table *pTab = 0; /* The table being read */ 144 const char *zCol; /* Name of the column of the table */ 145 int iSrc; /* Index in pTabList->a[] of table being read */ 146 int iDb; /* The index of the database the expression refers to */ 147 int iCol; /* Index of column in table */ 148 149 if( db->xAuth==0 ) return; 150 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 151 if( iDb<0 ){ 152 /* An attempt to read a column out of a subquery or other 153 ** temporary table. */ 154 return; 155 } 156 157 assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER ); 158 if( pExpr->op==TK_TRIGGER ){ 159 pTab = pParse->pTriggerTab; 160 }else{ 161 assert( pTabList ); 162 for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){ 163 if( pExpr->iTable==pTabList->a[iSrc].iCursor ){ 164 pTab = pTabList->a[iSrc].pTab; 165 break; 166 } 167 } 168 } 169 iCol = pExpr->iColumn; 170 if( NEVER(pTab==0) ) return; 171 172 if( iCol>=0 ){ 173 assert( iCol<pTab->nCol ); 174 zCol = pTab->aCol[iCol].zName; 175 }else if( pTab->iPKey>=0 ){ 176 assert( pTab->iPKey<pTab->nCol ); 177 zCol = pTab->aCol[pTab->iPKey].zName; 178 }else{ 179 zCol = "ROWID"; 180 } 181 assert( iDb>=0 && iDb<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. Return 189 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 190 ** is returned, then the error count and error message in pParse are 191 ** modified appropriately. 192 */ 193 int sqlite3AuthCheck( 194 Parse *pParse, 195 int code, 196 const char *zArg1, 197 const char *zArg2, 198 const char *zArg3 199 ){ 200 sqlite3 *db = pParse->db; 201 int rc; 202 203 /* Don't do any authorization checks if the database is initialising 204 ** or if the parser is being invoked from within sqlite3_declare_vtab. 205 */ 206 if( db->init.busy || IN_DECLARE_VTAB ){ 207 return SQLITE_OK; 208 } 209 210 if( db->xAuth==0 ){ 211 return SQLITE_OK; 212 } 213 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 214 if( rc==SQLITE_DENY ){ 215 sqlite3ErrorMsg(pParse, "not authorized"); 216 pParse->rc = SQLITE_AUTH; 217 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 218 rc = SQLITE_DENY; 219 sqliteAuthBadReturnCode(pParse); 220 } 221 return rc; 222 } 223 224 /* 225 ** Push an authorization context. After this routine is called, the 226 ** zArg3 argument to authorization callbacks will be zContext until 227 ** popped. Or if pParse==0, this routine is a no-op. 228 */ 229 void sqlite3AuthContextPush( 230 Parse *pParse, 231 AuthContext *pContext, 232 const char *zContext 233 ){ 234 assert( pParse ); 235 pContext->pParse = pParse; 236 pContext->zAuthContext = pParse->zAuthContext; 237 pParse->zAuthContext = zContext; 238 } 239 240 /* 241 ** Pop an authorization context that was previously pushed 242 ** by sqlite3AuthContextPush 243 */ 244 void sqlite3AuthContextPop(AuthContext *pContext){ 245 if( pContext->pParse ){ 246 pContext->pParse->zAuthContext = pContext->zAuthContext; 247 pContext->pParse = 0; 248 } 249 } 250 251 #endif /* SQLITE_OMIT_AUTHORIZATION */ 252