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//------------------------------------------------------------------------------
// <copyright file="NameValuePermission.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Data.Common {
using System.Collections;
using System.Data.Common;
using System.Diagnostics;
using System.Globalization;
using System.Security;
using System.Security.Permissions;
using System.Text;
[Serializable] // MDAC 83147
sealed internal class NameValuePermission : IComparable {
// reused as both key and value nodes
// key nodes link to value nodes
// value nodes link to key nodes
private string _value;
// value node with (null != _restrictions) are allowed to match connection strings
private DBConnectionString _entry;
private NameValuePermission[] _tree; // with branches
static internal readonly NameValuePermission Default = null;// = new NameValuePermission(String.Empty, new string[] { "File Name" }, KeyRestrictionBehavior.AllowOnly);
internal NameValuePermission() { // root node
}
private NameValuePermission(string keyword) {
_value = keyword;
}
private NameValuePermission(string value, DBConnectionString entry) {
_value = value;
_entry = entry;
}
private NameValuePermission(NameValuePermission permit) { // deep-copy
_value = permit._value;
_entry = permit._entry;
_tree = permit._tree;
if (null != _tree) {
NameValuePermission[] tree = (_tree.Clone() as NameValuePermission[]);
for(int i = 0; i < tree.Length; ++i) {
if (null != tree[i]) { // WebData 98488
tree[i] = tree[i].CopyNameValue(); // deep copy
}
}
_tree = tree;
}
}
int IComparable.CompareTo(object a) {
return StringComparer.Ordinal.Compare(_value, ((NameValuePermission)a)._value);
}
static internal void AddEntry(NameValuePermission kvtree, ArrayList entries, DBConnectionString entry) {
Debug.Assert(null != entry, "null DBConnectionString");
if (null != entry.KeyChain) {
for(NameValuePair keychain = entry.KeyChain; null != keychain; keychain = keychain.Next) {
NameValuePermission kv;
kv = kvtree.CheckKeyForValue(keychain.Name);
if (null == kv) {
kv = new NameValuePermission(keychain.Name);
kvtree.Add(kv); // add directly into live tree
}
kvtree = kv;
kv = kvtree.CheckKeyForValue(keychain.Value);
if (null == kv) {
DBConnectionString insertValue = ((null != keychain.Next) ? null : entry);
kv = new NameValuePermission(keychain.Value, insertValue);
kvtree.Add(kv); // add directly into live tree
if (null != insertValue) {
entries.Add(insertValue);
}
}
else if (null == keychain.Next) { // shorter chain potential
if (null != kv._entry) {
Debug.Assert(entries.Contains(kv._entry), "entries doesn't contain entry");
entries.Remove(kv._entry);
kv._entry = kv._entry.Intersect(entry); // union new restrictions into existing tree
}
else {
kv._entry = entry;
}
entries.Add(kv._entry);
}
kvtree = kv;
}
}
else { // global restrictions, MDAC 84443
DBConnectionString kentry = kvtree._entry;
if (null != kentry) {
Debug.Assert(entries.Contains(kentry), "entries doesn't contain entry");
entries.Remove(kentry);
kvtree._entry = kentry.Intersect(entry);
}
else {
kvtree._entry = entry;
}
entries.Add(kvtree._entry);
}
}
internal void Intersect(ArrayList entries, NameValuePermission target) {
if (null == target) {
_tree = null;
_entry = null;
}
else {
if (null != _entry) {
entries.Remove(_entry);
_entry = _entry.Intersect(target._entry);
entries.Add(_entry);
}
else if (null != target._entry) {
_entry = target._entry.Intersect(null);
entries.Add(_entry);
}
if (null != _tree) {
int count = _tree.Length;
for(int i = 0; i < _tree.Length; ++i) {
NameValuePermission kvtree = target.CheckKeyForValue(_tree[i]._value);
if (null != kvtree) { // does target tree contain our value
_tree[i].Intersect(entries, kvtree);
}
else {
_tree[i] = null;
--count;
}
}
if (0 == count) {
_tree = null;
}
else if (count < _tree.Length) {
NameValuePermission[] kvtree = new NameValuePermission[count];
for (int i = 0, j = 0; i < _tree.Length; ++i) {
if(null != _tree[i]) {
kvtree[j++] = _tree[i];
}
}
_tree = kvtree;
}
}
}
}
private void Add(NameValuePermission permit) {
NameValuePermission[] tree = _tree;
int length = ((null != tree) ? tree.Length : 0);
NameValuePermission[] newtree = new NameValuePermission[1+length];
for(int i = 0; i < newtree.Length-1; ++i) {
newtree[i] = tree[i];
}
newtree[length] = permit;
Array.Sort(newtree);
_tree = newtree;
}
internal bool CheckValueForKeyPermit(DBConnectionString parsetable) {
if (null == parsetable) {
return false;
}
bool hasMatch = false;
NameValuePermission[] keytree = _tree; // _tree won't mutate but Add will replace it
if (null != keytree) {
hasMatch = parsetable.IsEmpty; // MDAC 86773
if (!hasMatch) {
// which key do we follow the key-value chain on
for (int i = 0; i < keytree.Length; ++i) {
NameValuePermission permitKey = keytree[i];
if (null != permitKey) {
string keyword = permitKey._value;
#if DEBUG
Debug.Assert(null == permitKey._entry, "key member has no restrictions");
#endif
if (parsetable.ContainsKey(keyword)) {
string valueInQuestion = (string)parsetable[keyword];
// keyword is restricted to certain values
NameValuePermission permitValue = permitKey.CheckKeyForValue(valueInQuestion);
if (null != permitValue) {
//value does match - continue the chain down that branch
if (permitValue.CheckValueForKeyPermit(parsetable)) {
hasMatch = true;
// adding a break statement is tempting, but wrong
// user can safetly extend their restrictions for current rule to include missing keyword
// i.e. Add("provider=sqloledb;integrated security=sspi", "data provider=", KeyRestrictionBehavior.AllowOnly);
// i.e. Add("data provider=msdatashape;provider=sqloledb;integrated security=sspi", "", KeyRestrictionBehavior.AllowOnly);
}
else { // failed branch checking
return false;
}
}
else { // value doesn't match to expected values - fail here
return false;
}
}
}
// else try next keyword
}
}
// partial chain match, either leaf-node by shorter chain or fail mid-chain if (null == _restrictions)
}
DBConnectionString entry = _entry;
if (null != entry) {
// also checking !hasMatch is tempting, but wrong
// user can safetly extend their restrictions for current rule to include missing keyword
// i.e. Add("provider=sqloledb;integrated security=sspi", "data provider=", KeyRestrictionBehavior.AllowOnly);
// i.e. Add("provider=sqloledb;", "integrated security=;", KeyRestrictionBehavior.AllowOnly);
hasMatch = entry.IsSupersetOf(parsetable);
}
return hasMatch; // mid-chain failure
}
private NameValuePermission CheckKeyForValue(string keyInQuestion) {
NameValuePermission[] valuetree = _tree; // _tree won't mutate but Add will replace it
if (null != valuetree) {
for (int i = 0; i < valuetree.Length; ++i) {
NameValuePermission permitValue = valuetree[i];
if (String.Equals(keyInQuestion, permitValue._value, StringComparison.OrdinalIgnoreCase)) {
return permitValue;
}
}
}
return null;
}
internal NameValuePermission CopyNameValue() {
return new NameValuePermission(this);
}
}
}
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