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,v 1.12.2.1 2004/06/14 11:58:37 drh Exp $
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
115 if( db->xAuth==0 ) return;
116 assert( pExpr->op==TK_COLUMN );
117 for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){
118 if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
119 }
120 if( iSrc>=0 && iSrc<pTabList->nSrc ){
121 pTab = pTabList->a[iSrc].pTab;
122 }else{
123 /* This must be an attempt to read the NEW or OLD pseudo-tables
124 ** of a trigger.
125 */
126 TriggerStack *pStack; /* The stack of current triggers */
127 pStack = pParse->trigStack;
128 assert( pStack!=0 );
129 assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
130 pTab = pStack->pTab;
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