1 2 #pragma ident "%Z%%M% %I% %E% SMI" 3 4 /* 5 ** 2003 January 11 6 ** 7 ** The author disclaims copyright to this source code. In place of 8 ** a legal notice, here is a blessing: 9 ** 10 ** May you do good and not evil. 11 ** May you find forgiveness for yourself and forgive others. 12 ** May you share freely, never taking more than you give. 13 ** 14 ************************************************************************* 15 ** This file contains code used to implement the sqlite_set_authorizer() 16 ** API. This facility is an optional feature of the library. Embedded 17 ** systems that do not need this facility may omit it by recompiling 18 ** the library with -DSQLITE_OMIT_AUTHORIZATION=1 19 ** 20 ** $Id: auth.c,v 1.12.2.1 2004/06/14 11:58:37 drh Exp $ 21 */ 22 #include "sqliteInt.h" 23 24 /* 25 ** All of the code in this file may be omitted by defining a single 26 ** macro. 27 */ 28 #ifndef SQLITE_OMIT_AUTHORIZATION 29 30 /* 31 ** Set or clear the access authorization function. 32 ** 33 ** The access authorization function is be called during the compilation 34 ** phase to verify that the user has read and/or write access permission on 35 ** various fields of the database. The first argument to the auth function 36 ** is a copy of the 3rd argument to this routine. The second argument 37 ** to the auth function is one of these constants: 38 ** 39 ** SQLITE_COPY 40 ** SQLITE_CREATE_INDEX 41 ** SQLITE_CREATE_TABLE 42 ** SQLITE_CREATE_TEMP_INDEX 43 ** SQLITE_CREATE_TEMP_TABLE 44 ** SQLITE_CREATE_TEMP_TRIGGER 45 ** SQLITE_CREATE_TEMP_VIEW 46 ** SQLITE_CREATE_TRIGGER 47 ** SQLITE_CREATE_VIEW 48 ** SQLITE_DELETE 49 ** SQLITE_DROP_INDEX 50 ** SQLITE_DROP_TABLE 51 ** SQLITE_DROP_TEMP_INDEX 52 ** SQLITE_DROP_TEMP_TABLE 53 ** SQLITE_DROP_TEMP_TRIGGER 54 ** SQLITE_DROP_TEMP_VIEW 55 ** SQLITE_DROP_TRIGGER 56 ** SQLITE_DROP_VIEW 57 ** SQLITE_INSERT 58 ** SQLITE_PRAGMA 59 ** SQLITE_READ 60 ** SQLITE_SELECT 61 ** SQLITE_TRANSACTION 62 ** SQLITE_UPDATE 63 ** 64 ** The third and fourth arguments to the auth function are the name of 65 ** the table and the column that are being accessed. The auth function 66 ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If 67 ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY 68 ** means that the SQL statement will never-run - the sqlite_exec() call 69 ** will return with an error. SQLITE_IGNORE means that the SQL statement 70 ** should run but attempts to read the specified column will return NULL 71 ** and attempts to write the column will be ignored. 72 ** 73 ** Setting the auth function to NULL disables this hook. The default 74 ** setting of the auth function is NULL. 75 */ 76 int sqlite_set_authorizer( 77 sqlite *db, 78 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 79 void *pArg 80 ){ 81 db->xAuth = xAuth; 82 db->pAuthArg = pArg; 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, int rc){ 91 sqliteErrorMsg(pParse, "illegal return value (%d) from the " 92 "authorization function - should be SQLITE_OK, SQLITE_IGNORE, " 93 "or SQLITE_DENY", rc); 94 pParse->rc = SQLITE_MISUSE; 95 } 96 97 /* 98 ** The pExpr should be a TK_COLUMN expression. The table referred to 99 ** is in pTabList or else it is the NEW or OLD table of a trigger. 100 ** Check to see if it is OK to read this particular column. 101 ** 102 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 103 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 104 ** then generate an error. 105 */ 106 void sqliteAuthRead( 107 Parse *pParse, /* The parser context */ 108 Expr *pExpr, /* The expression to check authorization on */ 109 SrcList *pTabList /* All table that pExpr might refer to */ 110 ){ 111 sqlite *db = pParse->db; 112 int rc; 113 Table *pTab; /* The table being read */ 114 const char *zCol; /* Name of the column of the table */ 115 int iSrc; /* Index in pTabList->a[] of table being read */ 116 const char *zDBase; /* Name of database being accessed */ 117 118 if( db->xAuth==0 ) return; 119 assert( pExpr->op==TK_COLUMN ); 120 for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){ 121 if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break; 122 } 123 if( iSrc>=0 && iSrc<pTabList->nSrc ){ 124 pTab = pTabList->a[iSrc].pTab; 125 }else{ 126 /* This must be an attempt to read the NEW or OLD pseudo-tables 127 ** of a trigger. 128 */ 129 TriggerStack *pStack; /* The stack of current triggers */ 130 pStack = pParse->trigStack; 131 assert( pStack!=0 ); 132 assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx ); 133 pTab = pStack->pTab; 134 } 135 if( pTab==0 ) return; 136 if( pExpr->iColumn>=0 ){ 137 assert( pExpr->iColumn<pTab->nCol ); 138 zCol = pTab->aCol[pExpr->iColumn].zName; 139 }else if( pTab->iPKey>=0 ){ 140 assert( pTab->iPKey<pTab->nCol ); 141 zCol = pTab->aCol[pTab->iPKey].zName; 142 }else{ 143 zCol = "ROWID"; 144 } 145 assert( pExpr->iDb<db->nDb ); 146 zDBase = db->aDb[pExpr->iDb].zName; 147 rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 148 pParse->zAuthContext); 149 if( rc==SQLITE_IGNORE ){ 150 pExpr->op = TK_NULL; 151 }else if( rc==SQLITE_DENY ){ 152 if( db->nDb>2 || pExpr->iDb!=0 ){ 153 sqliteErrorMsg(pParse, "access to %s.%s.%s is prohibited", 154 zDBase, pTab->zName, zCol); 155 }else{ 156 sqliteErrorMsg(pParse, "access to %s.%s is prohibited", pTab->zName,zCol); 157 } 158 pParse->rc = SQLITE_AUTH; 159 }else if( rc!=SQLITE_OK ){ 160 sqliteAuthBadReturnCode(pParse, rc); 161 } 162 } 163 164 /* 165 ** Do an authorization check using the code and arguments given. Return 166 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 167 ** is returned, then the error count and error message in pParse are 168 ** modified appropriately. 169 */ 170 int sqliteAuthCheck( 171 Parse *pParse, 172 int code, 173 const char *zArg1, 174 const char *zArg2, 175 const char *zArg3 176 ){ 177 sqlite *db = pParse->db; 178 int rc; 179 180 if( db->init.busy || db->xAuth==0 ){ 181 return SQLITE_OK; 182 } 183 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 184 if( rc==SQLITE_DENY ){ 185 sqliteErrorMsg(pParse, "not authorized"); 186 pParse->rc = SQLITE_AUTH; 187 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 188 rc = SQLITE_DENY; 189 sqliteAuthBadReturnCode(pParse, rc); 190 } 191 return rc; 192 } 193 194 /* 195 ** Push an authorization context. After this routine is called, the 196 ** zArg3 argument to authorization callbacks will be zContext until 197 ** popped. Or if pParse==0, this routine is a no-op. 198 */ 199 void sqliteAuthContextPush( 200 Parse *pParse, 201 AuthContext *pContext, 202 const char *zContext 203 ){ 204 pContext->pParse = pParse; 205 if( pParse ){ 206 pContext->zAuthContext = pParse->zAuthContext; 207 pParse->zAuthContext = zContext; 208 } 209 } 210 211 /* 212 ** Pop an authorization context that was previously pushed 213 ** by sqliteAuthContextPush 214 */ 215 void sqliteAuthContextPop(AuthContext *pContext){ 216 if( pContext->pParse ){ 217 pContext->pParse->zAuthContext = pContext->zAuthContext; 218 pContext->pParse = 0; 219 } 220 } 221 222 #endif /* SQLITE_OMIT_AUTHORIZATION */ 223