1
2 #pragma ident "%Z%%M% %I% %E% SMI"
3
4 /*
5 ** 2003 January 11
6 **
7 ** The author disclaims copyright to this source code. In place of
8 ** a legal notice, here is a blessing:
9 **
10 ** May you do good and not evil.
11 ** May you find forgiveness for yourself and forgive others.
12 ** May you share freely, never taking more than you give.
13 **
14 *************************************************************************
15 ** This file contains code used to implement the sqlite_set_authorizer()
16 ** API. This facility is an optional feature of the library. Embedded
17 ** systems that do not need this facility may omit it by recompiling
18 ** the library with -DSQLITE_OMIT_AUTHORIZATION=1
19 **
20 ** $Id: auth.c,v 1.12.2.1 2004/06/14 11:58:37 drh Exp $
21 */
22 #include "sqliteInt.h"
23
24 /*
25 ** All of the code in this file may be omitted by defining a single
26 ** macro.
27 */
28 #ifndef SQLITE_OMIT_AUTHORIZATION
29
30 /*
31 ** Set or clear the access authorization function.
32 **
33 ** The access authorization function is be called during the compilation
34 ** phase to verify that the user has read and/or write access permission on
35 ** various fields of the database. The first argument to the auth function
36 ** is a copy of the 3rd argument to this routine. The second argument
37 ** to the auth function is one of these constants:
38 **
39 ** SQLITE_COPY
40 ** SQLITE_CREATE_INDEX
41 ** SQLITE_CREATE_TABLE
42 ** SQLITE_CREATE_TEMP_INDEX
43 ** SQLITE_CREATE_TEMP_TABLE
44 ** SQLITE_CREATE_TEMP_TRIGGER
45 ** SQLITE_CREATE_TEMP_VIEW
46 ** SQLITE_CREATE_TRIGGER
47 ** SQLITE_CREATE_VIEW
48 ** SQLITE_DELETE
49 ** SQLITE_DROP_INDEX
50 ** SQLITE_DROP_TABLE
51 ** SQLITE_DROP_TEMP_INDEX
52 ** SQLITE_DROP_TEMP_TABLE
53 ** SQLITE_DROP_TEMP_TRIGGER
54 ** SQLITE_DROP_TEMP_VIEW
55 ** SQLITE_DROP_TRIGGER
56 ** SQLITE_DROP_VIEW
57 ** SQLITE_INSERT
58 ** SQLITE_PRAGMA
59 ** SQLITE_READ
60 ** SQLITE_SELECT
61 ** SQLITE_TRANSACTION
62 ** SQLITE_UPDATE
63 **
64 ** The third and fourth arguments to the auth function are the name of
65 ** the table and the column that are being accessed. The auth function
66 ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If
67 ** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY
68 ** means that the SQL statement will never-run - the sqlite_exec() call
69 ** will return with an error. SQLITE_IGNORE means that the SQL statement
70 ** should run but attempts to read the specified column will return NULL
71 ** and attempts to write the column will be ignored.
72 **
73 ** Setting the auth function to NULL disables this hook. The default
74 ** setting of the auth function is NULL.
75 */
sqlite_set_authorizer(sqlite * db,int (* xAuth)(void *,int,const char *,const char *,const char *,const char *),void * pArg)76 int sqlite_set_authorizer(
77 sqlite *db,
78 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
79 void *pArg
80 ){
81 db->xAuth = xAuth;
82 db->pAuthArg = pArg;
83 return SQLITE_OK;
84 }
85
86 /*
87 ** Write an error message into pParse->zErrMsg that explains that the
88 ** user-supplied authorization function returned an illegal value.
89 */
sqliteAuthBadReturnCode(Parse * pParse,int rc)90 static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
91 sqliteErrorMsg(pParse, "illegal return value (%d) from the "
92 "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
93 "or SQLITE_DENY", rc);
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 */
sqliteAuthRead(Parse * pParse,Expr * pExpr,SrcList * pTabList)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 sqliteErrorMsg(pParse, "access to %s.%s.%s is prohibited",
154 zDBase, pTab->zName, zCol);
155 }else{
156 sqliteErrorMsg(pParse, "access to %s.%s is prohibited", pTab->zName,zCol);
157 }
158 pParse->rc = SQLITE_AUTH;
159 }else if( rc!=SQLITE_OK ){
160 sqliteAuthBadReturnCode(pParse, rc);
161 }
162 }
163
164 /*
165 ** Do an authorization check using the code and arguments given. Return
166 ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY
167 ** is returned, then the error count and error message in pParse are
168 ** modified appropriately.
169 */
sqliteAuthCheck(Parse * pParse,int code,const char * zArg1,const char * zArg2,const char * zArg3)170 int sqliteAuthCheck(
171 Parse *pParse,
172 int code,
173 const char *zArg1,
174 const char *zArg2,
175 const char *zArg3
176 ){
177 sqlite *db = pParse->db;
178 int rc;
179
180 if( db->init.busy || db->xAuth==0 ){
181 return SQLITE_OK;
182 }
183 rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
184 if( rc==SQLITE_DENY ){
185 sqliteErrorMsg(pParse, "not authorized");
186 pParse->rc = SQLITE_AUTH;
187 }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
188 rc = SQLITE_DENY;
189 sqliteAuthBadReturnCode(pParse, rc);
190 }
191 return rc;
192 }
193
194 /*
195 ** Push an authorization context. After this routine is called, the
196 ** zArg3 argument to authorization callbacks will be zContext until
197 ** popped. Or if pParse==0, this routine is a no-op.
198 */
sqliteAuthContextPush(Parse * pParse,AuthContext * pContext,const char * zContext)199 void sqliteAuthContextPush(
200 Parse *pParse,
201 AuthContext *pContext,
202 const char *zContext
203 ){
204 pContext->pParse = pParse;
205 if( pParse ){
206 pContext->zAuthContext = pParse->zAuthContext;
207 pParse->zAuthContext = zContext;
208 }
209 }
210
211 /*
212 ** Pop an authorization context that was previously pushed
213 ** by sqliteAuthContextPush
214 */
sqliteAuthContextPop(AuthContext * pContext)215 void sqliteAuthContextPop(AuthContext *pContext){
216 if( pContext->pParse ){
217 pContext->pParse->zAuthContext = pContext->zAuthContext;
218 pContext->pParse = 0;
219 }
220 }
221
222 #endif /* SQLITE_OMIT_AUTHORIZATION */
223