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 195361 2005-09-07 15:11:33Z iliaa $
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 99 : ){
78 99 : db->xAuth = xAuth;
79 99 : db->pAuthArg = pArg;
80 99 : 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 : sqliteErrorMsg(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_MISUSE;
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 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 1688 : ){
108 1688 : 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 : TriggerStack *pStack; /* The stack of current triggers */
115 :
116 1688 : if( db->xAuth==0 ) return;
117 : assert( pExpr->op==TK_COLUMN );
118 309 : for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){
119 309 : if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
120 : }
121 576 : if( iSrc>=0 && iSrc<pTabList->nSrc ){
122 288 : pTab = pTabList->a[iSrc].pTab;
123 0 : }else if( (pStack = pParse->trigStack)!=0 ){
124 : /* This must be an attempt to read the NEW or OLD pseudo-tables
125 : ** of a trigger.
126 : */
127 : assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
128 0 : pTab = pStack->pTab;
129 : }else{
130 0 : return;
131 : }
132 288 : if( pTab==0 ) return;
133 288 : if( pExpr->iColumn>=0 ){
134 : assert( pExpr->iColumn<pTab->nCol );
135 282 : zCol = pTab->aCol[pExpr->iColumn].zName;
136 6 : }else if( pTab->iPKey>=0 ){
137 : assert( pTab->iPKey<pTab->nCol );
138 6 : zCol = pTab->aCol[pTab->iPKey].zName;
139 : }else{
140 0 : zCol = "ROWID";
141 : }
142 : assert( pExpr->iDb<db->nDb );
143 288 : zDBase = db->aDb[pExpr->iDb].zName;
144 288 : rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase,
145 : pParse->zAuthContext);
146 288 : if( rc==SQLITE_IGNORE ){
147 0 : pExpr->op = TK_NULL;
148 288 : }else if( rc==SQLITE_DENY ){
149 0 : if( db->nDb>2 || pExpr->iDb!=0 ){
150 0 : sqliteErrorMsg(pParse, "access to %s.%s.%s is prohibited",
151 : zDBase, pTab->zName, zCol);
152 : }else{
153 0 : sqliteErrorMsg(pParse, "access to %s.%s is prohibited", pTab->zName,zCol);
154 : }
155 0 : pParse->rc = SQLITE_AUTH;
156 288 : }else if( rc!=SQLITE_OK ){
157 0 : 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 1687 : ){
174 1687 : sqlite *db = pParse->db;
175 : int rc;
176 :
177 1687 : if( db->init.busy || db->xAuth==0 ){
178 1241 : return SQLITE_OK;
179 : }
180 446 : rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
181 446 : if( rc==SQLITE_DENY ){
182 0 : sqliteErrorMsg(pParse, "not authorized");
183 0 : pParse->rc = SQLITE_AUTH;
184 446 : }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
185 0 : rc = SQLITE_DENY;
186 0 : sqliteAuthBadReturnCode(pParse, rc);
187 : }
188 446 : 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 0 : ){
201 0 : pContext->pParse = pParse;
202 0 : if( pParse ){
203 0 : pContext->zAuthContext = pParse->zAuthContext;
204 0 : pParse->zAuthContext = zContext;
205 : }
206 0 : }
207 :
208 : /*
209 : ** Pop an authorization context that was previously pushed
210 : ** by sqliteAuthContextPush
211 : */
212 5 : void sqliteAuthContextPop(AuthContext *pContext){
213 5 : if( pContext->pParse ){
214 0 : pContext->pParse->zAuthContext = pContext->zAuthContext;
215 0 : pContext->pParse = 0;
216 : }
217 5 : }
218 :
219 : #endif /* SQLITE_OMIT_AUTHORIZATION */
|
