xref: /PHP-5.3/ext/sqlite/libsqlite/src/auth.c (revision 9fa1ee36)
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 ** $Id$
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 */
sqlite_set_authorizer(sqlite * db,int (* xAuth)(void *,int,const char *,const char *,const char *,const char *),void * pArg)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 ){
78   db->xAuth = xAuth;
79   db->pAuthArg = pArg;
80   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 */
sqliteAuthBadReturnCode(Parse * pParse,int rc)87 static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
88   sqliteErrorMsg(pParse, "illegal return value (%d) from the "
89     "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
90     "or SQLITE_DENY", rc);
91   pParse->rc = SQLITE_MISUSE;
92 }
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 */
sqliteAuthRead(Parse * pParse,Expr * pExpr,SrcList * pTabList)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 ){
108   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   if( db->xAuth==0 ) return;
117   assert( pExpr->op==TK_COLUMN );
118   for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){
119     if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
120   }
121   if( iSrc>=0 && iSrc<pTabList->nSrc ){
122     pTab = pTabList->a[iSrc].pTab;
123   }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     pTab = pStack->pTab;
129   }else{
130     return;
131   }
132   if( pTab==0 ) return;
133   if( pExpr->iColumn>=0 ){
134     assert( pExpr->iColumn<pTab->nCol );
135     zCol = pTab->aCol[pExpr->iColumn].zName;
136   }else if( pTab->iPKey>=0 ){
137     assert( pTab->iPKey<pTab->nCol );
138     zCol = pTab->aCol[pTab->iPKey].zName;
139   }else{
140     zCol = "ROWID";
141   }
142   assert( pExpr->iDb<db->nDb );
143   zDBase = db->aDb[pExpr->iDb].zName;
144   rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase,
145                  pParse->zAuthContext);
146   if( rc==SQLITE_IGNORE ){
147     pExpr->op = TK_NULL;
148   }else if( rc==SQLITE_DENY ){
149     if( db->nDb>2 || pExpr->iDb!=0 ){
150       sqliteErrorMsg(pParse, "access to %s.%s.%s is prohibited",
151          zDBase, pTab->zName, zCol);
152     }else{
153       sqliteErrorMsg(pParse, "access to %s.%s is prohibited", pTab->zName,zCol);
154     }
155     pParse->rc = SQLITE_AUTH;
156   }else if( rc!=SQLITE_OK ){
157     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 */
sqliteAuthCheck(Parse * pParse,int code,const char * zArg1,const char * zArg2,const char * zArg3)167 int sqliteAuthCheck(
168   Parse *pParse,
169   int code,
170   const char *zArg1,
171   const char *zArg2,
172   const char *zArg3
173 ){
174   sqlite *db = pParse->db;
175   int rc;
176 
177   if( db->init.busy || db->xAuth==0 ){
178     return SQLITE_OK;
179   }
180   rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
181   if( rc==SQLITE_DENY ){
182     sqliteErrorMsg(pParse, "not authorized");
183     pParse->rc = SQLITE_AUTH;
184   }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
185     rc = SQLITE_DENY;
186     sqliteAuthBadReturnCode(pParse, rc);
187   }
188   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 */
sqliteAuthContextPush(Parse * pParse,AuthContext * pContext,const char * zContext)196 void sqliteAuthContextPush(
197   Parse *pParse,
198   AuthContext *pContext,
199   const char *zContext
200 ){
201   pContext->pParse = pParse;
202   if( pParse ){
203     pContext->zAuthContext = pParse->zAuthContext;
204     pParse->zAuthContext = zContext;
205   }
206 }
207 
208 /*
209 ** Pop an authorization context that was previously pushed
210 ** by sqliteAuthContextPush
211 */
sqliteAuthContextPop(AuthContext * pContext)212 void sqliteAuthContextPop(AuthContext *pContext){
213   if( pContext->pParse ){
214     pContext->pParse->zAuthContext = pContext->zAuthContext;
215     pContext->pParse = 0;
216   }
217 }
218 
219 #endif /* SQLITE_OMIT_AUTHORIZATION */
220