00001 /* 00002 ** 2003 January 11 00003 ** 00004 ** The author disclaims copyright to this source code. In place of 00005 ** a legal notice, here is a blessing: 00006 ** 00007 ** May you do good and not evil. 00008 ** May you find forgiveness for yourself and forgive others. 00009 ** May you share freely, never taking more than you give. 00010 ** 00011 ************************************************************************* 00012 ** This file contains code used to implement the sqlite3_set_authorizer() 00013 ** API. This facility is an optional feature of the library. Embedded 00014 ** systems that do not need this facility may omit it by recompiling 00015 ** the library with -DSQLITE_OMIT_AUTHORIZATION=1 00016 ** 00017 ** $Id: auth.c,v 1.29 2007/09/18 15:55:07 drh Exp $ 00018 */ 00019 #include "sqliteInt.h" 00020 00021 /* 00022 ** All of the code in this file may be omitted by defining a single 00023 ** macro. 00024 */ 00025 #ifndef SQLITE_OMIT_AUTHORIZATION 00026 00027 /* 00028 ** Set or clear the access authorization function. 00029 ** 00030 ** The access authorization function is be called during the compilation 00031 ** phase to verify that the user has read and/or write access permission on 00032 ** various fields of the database. The first argument to the auth function 00033 ** is a copy of the 3rd argument to this routine. The second argument 00034 ** to the auth function is one of these constants: 00035 ** 00036 ** SQLITE_CREATE_INDEX 00037 ** SQLITE_CREATE_TABLE 00038 ** SQLITE_CREATE_TEMP_INDEX 00039 ** SQLITE_CREATE_TEMP_TABLE 00040 ** SQLITE_CREATE_TEMP_TRIGGER 00041 ** SQLITE_CREATE_TEMP_VIEW 00042 ** SQLITE_CREATE_TRIGGER 00043 ** SQLITE_CREATE_VIEW 00044 ** SQLITE_DELETE 00045 ** SQLITE_DROP_INDEX 00046 ** SQLITE_DROP_TABLE 00047 ** SQLITE_DROP_TEMP_INDEX 00048 ** SQLITE_DROP_TEMP_TABLE 00049 ** SQLITE_DROP_TEMP_TRIGGER 00050 ** SQLITE_DROP_TEMP_VIEW 00051 ** SQLITE_DROP_TRIGGER 00052 ** SQLITE_DROP_VIEW 00053 ** SQLITE_INSERT 00054 ** SQLITE_PRAGMA 00055 ** SQLITE_READ 00056 ** SQLITE_SELECT 00057 ** SQLITE_TRANSACTION 00058 ** SQLITE_UPDATE 00059 ** 00060 ** The third and fourth arguments to the auth function are the name of 00061 ** the table and the column that are being accessed. The auth function 00062 ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If 00063 ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY 00064 ** means that the SQL statement will never-run - the sqlite3_exec() call 00065 ** will return with an error. SQLITE_IGNORE means that the SQL statement 00066 ** should run but attempts to read the specified column will return NULL 00067 ** and attempts to write the column will be ignored. 00068 ** 00069 ** Setting the auth function to NULL disables this hook. The default 00070 ** setting of the auth function is NULL. 00071 */ 00072 int sqlite3_set_authorizer( 00073 sqlite3 *db, 00074 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 00075 void *pArg 00076 ){ 00077 sqlite3_mutex_enter(db->mutex); 00078 db->xAuth = xAuth; 00079 db->pAuthArg = pArg; 00080 sqlite3ExpirePreparedStatements(db); 00081 sqlite3_mutex_leave(db->mutex); 00082 return SQLITE_OK; 00083 } 00084 00085 /* 00086 ** Write an error message into pParse->zErrMsg that explains that the 00087 ** user-supplied authorization function returned an illegal value. 00088 */ 00089 static void sqliteAuthBadReturnCode(Parse *pParse, int rc){ 00090 sqlite3ErrorMsg(pParse, "illegal return value (%d) from the " 00091 "authorization function - should be SQLITE_OK, SQLITE_IGNORE, " 00092 "or SQLITE_DENY", rc); 00093 pParse->rc = SQLITE_ERROR; 00094 } 00095 00096 /* 00097 ** The pExpr should be a TK_COLUMN expression. The table referred to 00098 ** is in pTabList or else it is the NEW or OLD table of a trigger. 00099 ** Check to see if it is OK to read this particular column. 00100 ** 00101 ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 00102 ** instruction into a TK_NULL. If the auth function returns SQLITE_DENY, 00103 ** then generate an error. 00104 */ 00105 void sqlite3AuthRead( 00106 Parse *pParse, /* The parser context */ 00107 Expr *pExpr, /* The expression to check authorization on */ 00108 Schema *pSchema, /* The schema of the expression */ 00109 SrcList *pTabList /* All table that pExpr might refer to */ 00110 ){ 00111 sqlite3 *db = pParse->db; 00112 int rc; 00113 Table *pTab = 0; /* The table being read */ 00114 const char *zCol; /* Name of the column of the table */ 00115 int iSrc; /* Index in pTabList->a[] of table being read */ 00116 const char *zDBase; /* Name of database being accessed */ 00117 TriggerStack *pStack; /* The stack of current triggers */ 00118 int iDb; /* The index of the database the expression refers to */ 00119 00120 if( db->xAuth==0 ) return; 00121 if( pExpr->op!=TK_COLUMN ) return; 00122 iDb = sqlite3SchemaToIndex(pParse->db, pSchema); 00123 if( iDb<0 ){ 00124 /* An attempt to read a column out of a subquery or other 00125 ** temporary table. */ 00126 return; 00127 } 00128 for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){ 00129 if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break; 00130 } 00131 if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){ 00132 pTab = pTabList->a[iSrc].pTab; 00133 }else if( (pStack = pParse->trigStack)!=0 ){ 00134 /* This must be an attempt to read the NEW or OLD pseudo-tables 00135 ** of a trigger. 00136 */ 00137 assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx ); 00138 pTab = pStack->pTab; 00139 } 00140 if( pTab==0 ) return; 00141 if( pExpr->iColumn>=0 ){ 00142 assert( pExpr->iColumn<pTab->nCol ); 00143 zCol = pTab->aCol[pExpr->iColumn].zName; 00144 }else if( pTab->iPKey>=0 ){ 00145 assert( pTab->iPKey<pTab->nCol ); 00146 zCol = pTab->aCol[pTab->iPKey].zName; 00147 }else{ 00148 zCol = "ROWID"; 00149 } 00150 assert( iDb>=0 && iDb<db->nDb ); 00151 zDBase = db->aDb[iDb].zName; 00152 rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 00153 pParse->zAuthContext); 00154 if( rc==SQLITE_IGNORE ){ 00155 pExpr->op = TK_NULL; 00156 }else if( rc==SQLITE_DENY ){ 00157 if( db->nDb>2 || iDb!=0 ){ 00158 sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited", 00159 zDBase, pTab->zName, zCol); 00160 }else{ 00161 sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol); 00162 } 00163 pParse->rc = SQLITE_AUTH; 00164 }else if( rc!=SQLITE_OK ){ 00165 sqliteAuthBadReturnCode(pParse, rc); 00166 } 00167 } 00168 00169 /* 00170 ** Do an authorization check using the code and arguments given. Return 00171 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY 00172 ** is returned, then the error count and error message in pParse are 00173 ** modified appropriately. 00174 */ 00175 int sqlite3AuthCheck( 00176 Parse *pParse, 00177 int code, 00178 const char *zArg1, 00179 const char *zArg2, 00180 const char *zArg3 00181 ){ 00182 sqlite3 *db = pParse->db; 00183 int rc; 00184 00185 /* Don't do any authorization checks if the database is initialising 00186 ** or if the parser is being invoked from within sqlite3_declare_vtab. 00187 */ 00188 if( db->init.busy || IN_DECLARE_VTAB ){ 00189 return SQLITE_OK; 00190 } 00191 00192 if( db->xAuth==0 ){ 00193 return SQLITE_OK; 00194 } 00195 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext); 00196 if( rc==SQLITE_DENY ){ 00197 sqlite3ErrorMsg(pParse, "not authorized"); 00198 pParse->rc = SQLITE_AUTH; 00199 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){ 00200 rc = SQLITE_DENY; 00201 sqliteAuthBadReturnCode(pParse, rc); 00202 } 00203 return rc; 00204 } 00205 00206 /* 00207 ** Push an authorization context. After this routine is called, the 00208 ** zArg3 argument to authorization callbacks will be zContext until 00209 ** popped. Or if pParse==0, this routine is a no-op. 00210 */ 00211 void sqlite3AuthContextPush( 00212 Parse *pParse, 00213 AuthContext *pContext, 00214 const char *zContext 00215 ){ 00216 pContext->pParse = pParse; 00217 if( pParse ){ 00218 pContext->zAuthContext = pParse->zAuthContext; 00219 pParse->zAuthContext = zContext; 00220 } 00221 } 00222 00223 /* 00224 ** Pop an authorization context that was previously pushed 00225 ** by sqlite3AuthContextPush 00226 */ 00227 void sqlite3AuthContextPop(AuthContext *pContext){ 00228 if( pContext->pParse ){ 00229 pContext->pParse->zAuthContext = pContext->zAuthContext; 00230 pContext->pParse = 0; 00231 } 00232 } 00233 00234 #endif /* SQLITE_OMIT_AUTHORIZATION */
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