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 1.10 2003/05/10 03:36:54 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 char zBuf[20]; 89 sprintf(zBuf, "(%d)", rc); 90 sqliteSetString(&pParse->zErrMsg, "illegal return value ", zBuf, 91 " from the authorization function - should be SQLITE_OK, " 92 "SQLITE_IGNORE, or SQLITE_DENY", 0); 93 pParse->nErr++; 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 sqliteSetString(&pParse->zErrMsg,"access to ", zDBase, ".", 154 pTab->zName, ".", zCol, " is prohibited", 0); 155 }else{ 156 sqliteSetString(&pParse->zErrMsg,"access to ", pTab->zName, ".", 157 zCol, " is prohibited", 0); 158 } 159 pParse->nErr++; 160 pParse->rc = SQLITE_AUTH; 161 }else if( rc!=SQLITE_OK ){ 162 sqliteAuthBadReturnCode(pParse, rc); 163 } 164 } 165 166 /* 167 ** Do an authorization check using the code and arguments given. Return 168 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 169 ** is returned, then the error count and error message in pParse are 170 ** modified appropriately. 171 */ 172 int sqliteAuthCheck( 173 Parse *pParse, 174 int code, 175 const char *zArg1, 176 const char *zArg2, 177 const char *zArg3 178 ){ 179 sqlite *db = pParse->db; 180 int rc; 181 182 if( db->xAuth==0 ){ 183 return SQLITE_OK; 184 } 185 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 186 if( rc==SQLITE_DENY ){ 187 sqliteSetString(&pParse->zErrMsg, "not authorized", 0); 188 pParse->rc = SQLITE_AUTH; 189 pParse->nErr++; 190 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 191 rc = SQLITE_DENY; 192 sqliteAuthBadReturnCode(pParse, rc); 193 } 194 return rc; 195 } 196 197 /* 198 ** Push an authorization context. After this routine is called, the 199 ** zArg3 argument to authorization callbacks will be zContext until 200 ** popped. Or if pParse==0, this routine is a no-op. 201 */ 202 void sqliteAuthContextPush( 203 Parse *pParse, 204 AuthContext *pContext, 205 const char *zContext 206 ){ 207 pContext->pParse = pParse; 208 if( pParse ){ 209 pContext->zAuthContext = pParse->zAuthContext; 210 pParse->zAuthContext = zContext; 211 } 212 } 213 214 /* 215 ** Pop an authorization context that was previously pushed 216 ** by sqliteAuthContextPush 217 */ 218 void sqliteAuthContextPop(AuthContext *pContext){ 219 if( pContext->pParse ){ 220 pContext->pParse->zAuthContext = pContext->zAuthContext; 221 pContext->pParse = 0; 222 } 223 } 224 225 #endif /* SQLITE_OMIT_AUTHORIZATION */ 226