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 sqlite_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 1.12.2.1 2004/06/14 11:58:37 drh 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_COPY 37 ** SQLITE_CREATE_INDEX 38 ** SQLITE_CREATE_TABLE 39 ** SQLITE_CREATE_TEMP_INDEX 40 ** SQLITE_CREATE_TEMP_TABLE 41 ** SQLITE_CREATE_TEMP_TRIGGER 42 ** SQLITE_CREATE_TEMP_VIEW 43 ** SQLITE_CREATE_TRIGGER 44 ** SQLITE_CREATE_VIEW 45 ** SQLITE_DELETE 46 ** SQLITE_DROP_INDEX 47 ** SQLITE_DROP_TABLE 48 ** SQLITE_DROP_TEMP_INDEX 49 ** SQLITE_DROP_TEMP_TABLE 50 ** SQLITE_DROP_TEMP_TRIGGER 51 ** SQLITE_DROP_TEMP_VIEW 52 ** SQLITE_DROP_TRIGGER 53 ** SQLITE_DROP_VIEW 54 ** SQLITE_INSERT 55 ** SQLITE_PRAGMA 56 ** SQLITE_READ 57 ** SQLITE_SELECT 58 ** SQLITE_TRANSACTION 59 ** SQLITE_UPDATE 60 ** 61 ** The third and fourth arguments to the auth function are the name of 62 ** the table and the column that are being accessed. The auth function 63 ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If 64 ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY 65 ** means that the SQL statement will never-run - the sqlite_exec() call 66 ** will return with an error. SQLITE_IGNORE means that the SQL statement 67 ** should run but attempts to read the specified column will return NULL 68 ** and attempts to write the column will be ignored. 69 ** 70 ** Setting the auth function to NULL disables this hook. The default 71 ** setting of the auth function is NULL. 72 */ 73 int sqlite_set_authorizer( 74 sqlite *db, 75 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 76 void *pArg 77 ){ 78 db->xAuth = xAuth; 79 db->pAuthArg = pArg; 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, int rc){ 88 sqliteErrorMsg(pParse, "illegal return value (%d) from the " 89 "authorization function - should be SQLITE_OK, SQLITE_IGNORE, " 90 "or SQLITE_DENY", rc); 91 pParse->rc = SQLITE_MISUSE; 92 } 93 94 /* 95 ** The pExpr should be a TK_COLUMN expression. The table referred to 96 ** is in pTabList or else it is the NEW or OLD table of a trigger. 97 ** Check to see if it is OK to read this particular column. 98 ** 99 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 100 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 101 ** then generate an error. 102 */ 103 void sqliteAuthRead( 104 Parse *pParse, /* The parser context */ 105 Expr *pExpr, /* The expression to check authorization on */ 106 SrcList *pTabList /* All table that pExpr might refer to */ 107 ){ 108 sqlite *db = pParse->db; 109 int rc; 110 Table *pTab; /* The table being read */ 111 const char *zCol; /* Name of the column of the table */ 112 int iSrc; /* Index in pTabList->a[] of table being read */ 113 const char *zDBase; /* Name of database being accessed */ 114 115 if( db->xAuth==0 ) return; 116 assert( pExpr->op==TK_COLUMN ); 117 for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){ 118 if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break; 119 } 120 if( iSrc>=0 && iSrc<pTabList->nSrc ){ 121 pTab = pTabList->a[iSrc].pTab; 122 }else{ 123 /* This must be an attempt to read the NEW or OLD pseudo-tables 124 ** of a trigger. 125 */ 126 TriggerStack *pStack; /* The stack of current triggers */ 127 pStack = pParse->trigStack; 128 assert( pStack!=0 ); 129 assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx ); 130 pTab = pStack->pTab; 131 } 132 if( pTab==0 ) return; 133 if( pExpr->iColumn>=0 ){ 134 assert( pExpr->iColumn<pTab->nCol ); 135 zCol = pTab->aCol[pExpr->iColumn].zName; 136 }else if( pTab->iPKey>=0 ){ 137 assert( pTab->iPKey<pTab->nCol ); 138 zCol = pTab->aCol[pTab->iPKey].zName; 139 }else{ 140 zCol = "ROWID"; 141 } 142 assert( pExpr->iDb<db->nDb ); 143 zDBase = db->aDb[pExpr->iDb].zName; 144 rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 145 pParse->zAuthContext); 146 if( rc==SQLITE_IGNORE ){ 147 pExpr->op = TK_NULL; 148 }else if( rc==SQLITE_DENY ){ 149 if( db->nDb>2 || pExpr->iDb!=0 ){ 150 sqliteErrorMsg(pParse, "access to %s.%s.%s is prohibited", 151 zDBase, pTab->zName, zCol); 152 }else{ 153 sqliteErrorMsg(pParse, "access to %s.%s is prohibited", pTab->zName,zCol); 154 } 155 pParse->rc = SQLITE_AUTH; 156 }else if( rc!=SQLITE_OK ){ 157 sqliteAuthBadReturnCode(pParse, rc); 158 } 159 } 160 161 /* 162 ** Do an authorization check using the code and arguments given. Return 163 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 164 ** is returned, then the error count and error message in pParse are 165 ** modified appropriately. 166 */ 167 int sqliteAuthCheck( 168 Parse *pParse, 169 int code, 170 const char *zArg1, 171 const char *zArg2, 172 const char *zArg3 173 ){ 174 sqlite *db = pParse->db; 175 int rc; 176 177 if( db->init.busy || db->xAuth==0 ){ 178 return SQLITE_OK; 179 } 180 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 181 if( rc==SQLITE_DENY ){ 182 sqliteErrorMsg(pParse, "not authorized"); 183 pParse->rc = SQLITE_AUTH; 184 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 185 rc = SQLITE_DENY; 186 sqliteAuthBadReturnCode(pParse, rc); 187 } 188 return rc; 189 } 190 191 /* 192 ** Push an authorization context. After this routine is called, the 193 ** zArg3 argument to authorization callbacks will be zContext until 194 ** popped. Or if pParse==0, this routine is a no-op. 195 */ 196 void sqliteAuthContextPush( 197 Parse *pParse, 198 AuthContext *pContext, 199 const char *zContext 200 ){ 201 pContext->pParse = pParse; 202 if( pParse ){ 203 pContext->zAuthContext = pParse->zAuthContext; 204 pParse->zAuthContext = zContext; 205 } 206 } 207 208 /* 209 ** Pop an authorization context that was previously pushed 210 ** by sqliteAuthContextPush 211 */ 212 void sqliteAuthContextPop(AuthContext *pContext){ 213 if( pContext->pParse ){ 214 pContext->pParse->zAuthContext = pContext->zAuthContext; 215 pContext->pParse = 0; 216 } 217 } 218 219 #endif /* SQLITE_OMIT_AUTHORIZATION */ 220