DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Untracked file

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232
/*
** 2003 January 11
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the sqlite3_set_authorizer()
** API.  This facility is an optional feature of the library.  Embedded
** systems that do not need this facility may omit it by recompiling
** the library with -DSQLITE_OMIT_AUTHORIZATION=1
**
** $Id: auth.c,v 1.24 2006/01/13 13:55:45 drh Exp $
*/
#include "sqliteInt.h"

/*
** All of the code in this file may be omitted by defining a single
** macro.
*/
#ifndef SQLITE_OMIT_AUTHORIZATION

/*
** Set or clear the access authorization function.
**
** The access authorization function is be called during the compilation
** phase to verify that the user has read and/or write access permission on
** various fields of the database.  The first argument to the auth function
** is a copy of the 3rd argument to this routine.  The second argument
** to the auth function is one of these constants:
**
**       SQLITE_CREATE_INDEX
**       SQLITE_CREATE_TABLE
**       SQLITE_CREATE_TEMP_INDEX
**       SQLITE_CREATE_TEMP_TABLE
**       SQLITE_CREATE_TEMP_TRIGGER
**       SQLITE_CREATE_TEMP_VIEW
**       SQLITE_CREATE_TRIGGER
**       SQLITE_CREATE_VIEW
**       SQLITE_DELETE
**       SQLITE_DROP_INDEX
**       SQLITE_DROP_TABLE
**       SQLITE_DROP_TEMP_INDEX
**       SQLITE_DROP_TEMP_TABLE
**       SQLITE_DROP_TEMP_TRIGGER
**       SQLITE_DROP_TEMP_VIEW
**       SQLITE_DROP_TRIGGER
**       SQLITE_DROP_VIEW
**       SQLITE_INSERT
**       SQLITE_PRAGMA
**       SQLITE_READ
**       SQLITE_SELECT
**       SQLITE_TRANSACTION
**       SQLITE_UPDATE
**
** The third and fourth arguments to the auth function are the name of
** the table and the column that are being accessed.  The auth function
** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  If
** SQLITE_OK is returned, it means that access is allowed.  SQLITE_DENY
** means that the SQL statement will never-run - the sqlite3_exec() call
** will return with an error.  SQLITE_IGNORE means that the SQL statement
** should run but attempts to read the specified column will return NULL
** and attempts to write the column will be ignored.
**
** Setting the auth function to NULL disables this hook.  The default
** setting of the auth function is NULL.
*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){
  db->xAuth = xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);
  return SQLITE_OK;
}

/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/
static void sqliteAuthBadReturnCode(Parse *pParse, int rc){
  sqlite3ErrorMsg(pParse, "illegal return value (%d) from the "
    "authorization function - should be SQLITE_OK, SQLITE_IGNORE, "
    "or SQLITE_DENY", rc);
  pParse->rc = SQLITE_ERROR;
}

/*
** The pExpr should be a TK_COLUMN expression.  The table referred to
** is in pTabList or else it is the NEW or OLD table of a trigger.  
** Check to see if it is OK to read this particular column.
**
** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 
** instruction into a TK_NULL.  If the auth function returns SQLITE_DENY,
** then generate an error.
*/
void sqlite3AuthRead(
  Parse *pParse,        /* The parser context */
  Expr *pExpr,          /* The expression to check authorization on */
  SrcList *pTabList     /* All table that pExpr might refer to */
){
  sqlite3 *db = pParse->db;
  int rc;
  Table *pTab;          /* The table being read */
  const char *zCol;     /* Name of the column of the table */
  int iSrc;             /* Index in pTabList->a[] of table being read */
  const char *zDBase;   /* Name of database being accessed */
  TriggerStack *pStack; /* The stack of current triggers */
  int iDb;              /* The index of the database the expression refers to */

  if( db->xAuth==0 ) return;
  if( pExpr->op==TK_AS ) return;
  assert( pExpr->op==TK_COLUMN );
  iDb = sqlite3SchemaToIndex(pParse->db, pExpr->pSchema);
  if( iDb<0 ){
    /* An attempt to read a column out of a subquery or other
    ** temporary table. */
    return;
  }
  for(iSrc=0; pTabList && iSrc<pTabList->nSrc; iSrc++){
    if( pExpr->iTable==pTabList->a[iSrc].iCursor ) break;
  }
  if( iSrc>=0 && pTabList && iSrc<pTabList->nSrc ){
    pTab = pTabList->a[iSrc].pTab;
  }else if( (pStack = pParse->trigStack)!=0 ){
    /* This must be an attempt to read the NEW or OLD pseudo-tables
    ** of a trigger.
    */
    assert( pExpr->iTable==pStack->newIdx || pExpr->iTable==pStack->oldIdx );
    pTab = pStack->pTab;
  }else{
    return;
  }
  if( pTab==0 ) return;
  if( pExpr->iColumn>=0 ){
    assert( pExpr->iColumn<pTab->nCol );
    zCol = pTab->aCol[pExpr->iColumn].zName;
  }else if( pTab->iPKey>=0 ){
    assert( pTab->iPKey<pTab->nCol );
    zCol = pTab->aCol[pTab->iPKey].zName;
  }else{
    zCol = "ROWID";
  }
  assert( iDb>=0 && iDb<db->nDb );
  zDBase = db->aDb[iDb].zName;
  rc = db->xAuth(db->pAuthArg, SQLITE_READ, pTab->zName, zCol, zDBase, 
                 pParse->zAuthContext);
  if( rc==SQLITE_IGNORE ){
    pExpr->op = TK_NULL;
  }else if( rc==SQLITE_DENY ){
    if( db->nDb>2 || iDb!=0 ){
      sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited", 
         zDBase, pTab->zName, zCol);
    }else{
      sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited",pTab->zName,zCol);
    }
    pParse->rc = SQLITE_AUTH;
  }else if( rc!=SQLITE_OK ){
    sqliteAuthBadReturnCode(pParse, rc);
  }
}

/*
** Do an authorization check using the code and arguments given.  Return
** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY.  If SQLITE_DENY
** is returned, then the error count and error message in pParse are
** modified appropriately.
*/
int sqlite3AuthCheck(
  Parse *pParse,
  int code,
  const char *zArg1,
  const char *zArg2,
  const char *zArg3
){
  sqlite3 *db = pParse->db;
  int rc;

  /* Don't do any authorization checks if the database is initialising. */
  if( db->init.busy ){
    return SQLITE_OK;
  }

  if( db->xAuth==0 ){
    return SQLITE_OK;
  }
  rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext);
  if( rc==SQLITE_DENY ){
    sqlite3ErrorMsg(pParse, "not authorized");
    pParse->rc = SQLITE_AUTH;
  }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
    rc = SQLITE_DENY;
    sqliteAuthBadReturnCode(pParse, rc);
  }
  return rc;
}

/*
** Push an authorization context.  After this routine is called, the
** zArg3 argument to authorization callbacks will be zContext until
** popped.  Or if pParse==0, this routine is a no-op.
*/
void sqlite3AuthContextPush(
  Parse *pParse,
  AuthContext *pContext, 
  const char *zContext
){
  pContext->pParse = pParse;
  if( pParse ){
    pContext->zAuthContext = pParse->zAuthContext;
    pParse->zAuthContext = zContext;
  }
}

/*
** Pop an authorization context that was previously pushed
** by sqlite3AuthContextPush
*/
void sqlite3AuthContextPop(AuthContext *pContext){
  if( pContext->pParse ){
    pContext->pParse->zAuthContext = pContext->zAuthContext;
    pContext->pParse = 0;
  }
}

#endif /* SQLITE_OMIT_AUTHORIZATION */