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 : ** $Id$
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 0 : ){
77 0 : db->xAuth = xAuth;
78 0 : db->pAuthArg = pArg;
79 0 : sqlite3ExpirePreparedStatements(db);
80 0 : 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 0 : static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
88 0 : sqlite3ErrorMsg(pParse, "illegal return value (%d) from the "
89 : "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
90 : "or SQLITE_DENY", rc);
91 0 : pParse->rc = SQLITE_ERROR;
92 0 : }
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 sqlite3AuthRead(
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 */
107 483 : ){
108 483 : sqlite3 *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 : TriggerStack *pStack; /* The stack of current triggers */
115 : int iDb; /* The index of the database the expression refers to */
116 :
117 483 : if( db->xAuth==0 ) return;
118 0 : if( pExpr->op==TK_AS ) return;
119 : assert( pExpr->op==TK_COLUMN );
120 0 : iDb = sqlite3SchemaToIndex(pParse->db, pExpr->pSchema);
121 0 : if( iDb<0 ){
122 : /* An attempt to read a column out of a subquery or other
123 : ** temporary table. */
124 0 : return;
125 : }
126 0 : for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){
127 0 : if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
128 : }
129 0 : if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){
130 0 : pTab = pTabList->a[iSrc].pTab;
131 0 : }else if( (pStack = pParse->trigStack)!=0 ){
132 : /* This must be an attempt to read the NEW or OLD pseudo-tables
133 : ** of a trigger.
134 : */
135 : assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
136 0 : pTab = pStack->pTab;
137 : }else{
138 0 : return;
139 : }
140 0 : if( pTab==0 ) return;
141 0 : if( pExpr->iColumn>=0 ){
142 : assert( pExpr->iColumn<pTab->nCol );
143 0 : zCol = pTab->aCol[pExpr->iColumn].zName;
144 0 : }else if( pTab->iPKey>=0 ){
145 : assert( pTab->iPKey<pTab->nCol );
146 0 : zCol = pTab->aCol[pTab->iPKey].zName;
147 : }else{
148 0 : zCol = "ROWID";
149 : }
150 : assert( iDb>=0 && iDb<db->nDb );
151 0 : zDBase = db->aDb[iDb].zName;
152 0 : rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase,
153 : pParse->zAuthContext);
154 0 : if( rc==SQLITE_IGNORE ){
155 0 : pExpr->op = TK_NULL;
156 0 : }else if( rc==SQLITE_DENY ){
157 0 : if( db->nDb>2 || iDb!=0 ){
158 0 : sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",
159 : zDBase, pTab->zName, zCol);
160 : }else{
161 0 : sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol);
162 : }
163 0 : pParse->rc = SQLITE_AUTH;
164 0 : }else if( rc!=SQLITE_OK ){
165 0 : sqliteAuthBadReturnCode(pParse, rc);
166 : }
167 : }
168 :
169 : /*
170 : ** Do an authorization check using the code and arguments given. Return
171 : ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY
172 : ** is returned, then the error count and error message in pParse are
173 : ** modified appropriately.
174 : */
175 : int sqlite3AuthCheck(
176 : Parse *pParse,
177 : int code,
178 : const char *zArg1,
179 : const char *zArg2,
180 : const char *zArg3
181 1465 : ){
182 1465 : sqlite3 *db = pParse->db;
183 : int rc;
184 :
185 : /* Don't do any authorization checks if the database is initialising
186 : ** or if the parser is being invoked from within sqlite3_declare_vtab.
187 : */
188 1465 : if( db->init.busy || IN_DECLARE_VTAB ){
189 685 : return SQLITE_OK;
190 : }
191 :
192 780 : if( db->xAuth==0 ){
193 780 : return SQLITE_OK;
194 : }
195 0 : rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
196 0 : if( rc==SQLITE_DENY ){
197 0 : sqlite3ErrorMsg(pParse, "not authorized");
198 0 : pParse->rc = SQLITE_AUTH;
199 0 : }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
200 0 : rc = SQLITE_DENY;
201 0 : sqliteAuthBadReturnCode(pParse, rc);
202 : }
203 0 : return rc;
204 : }
205 :
206 : /*
207 : ** Push an authorization context. After this routine is called, the
208 : ** zArg3 argument to authorization callbacks will be zContext until
209 : ** popped. Or if pParse==0, this routine is a no-op.
210 : */
211 : void sqlite3AuthContextPush(
212 : Parse *pParse,
213 : AuthContext *pContext,
214 : const char *zContext
215 0 : ){
216 0 : pContext->pParse = pParse;
217 0 : if( pParse ){
218 0 : pContext->zAuthContext = pParse->zAuthContext;
219 0 : pParse->zAuthContext = zContext;
220 : }
221 0 : }
222 :
223 : /*
224 : ** Pop an authorization context that was previously pushed
225 : ** by sqlite3AuthContextPush
226 : */
227 70 : void sqlite3AuthContextPop(AuthContext *pContext){
228 70 : if( pContext->pParse ){
229 0 : pContext->pParse->zAuthContext = pContext->zAuthContext;
230 0 : pContext->pParse = 0;
231 : }
232 70 : }
233 :
234 : #endif /* SQLITE_OMIT_AUTHORIZATION */
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