xref: /illumos-gate/usr/src/lib/libsqlite/src/auth.c (revision c5c4113d)
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