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//------------------------------------------------------------------------------
// <copyright file="RsaProtectedConfigurationProvider.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Configuration
{
using System.Collections.Specialized;
using System.Runtime.Serialization;
using System.Configuration.Provider;
using System.Xml;
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.IO;
using System.Runtime.InteropServices;
using Microsoft.Win32;
using System.Security.Permissions;
using System.Diagnostics.CodeAnalysis;
[PermissionSet(SecurityAction.Demand, Name = "FullTrust")]
public sealed class RsaProtectedConfigurationProvider : ProtectedConfigurationProvider
{
// Note: this name has to match the name used in RegiisUtility
const string DefaultRsaKeyContainerName = "NetFrameworkConfigurationKey";
public override XmlNode Decrypt(XmlNode encryptedNode)
{
XmlDocument xmlDocument = new XmlDocument();
EncryptedXml exml = null;
RSACryptoServiceProvider rsa = GetCryptoServiceProvider(false, true);
xmlDocument.PreserveWhitespace = true;
ProtectedConfigurationProvider.LoadXml(xmlDocument, encryptedNode.OuterXml);
exml = new FipsAwareEncryptedXml(xmlDocument);
exml.AddKeyNameMapping(_KeyName, rsa);
exml.DecryptDocument();
rsa.Clear();
return xmlDocument.DocumentElement;
}
public override XmlNode Encrypt(XmlNode node)
{
XmlDocument xmlDocument;
EncryptedXml exml;
byte[] rgbOutput;
EncryptedData ed;
KeyInfoName kin;
EncryptedKey ek;
KeyInfoEncryptedKey kek;
XmlElement inputElement;
RSACryptoServiceProvider rsa = GetCryptoServiceProvider(false, false);
// Encrypt the node with the new key
xmlDocument = new XmlDocument();
xmlDocument.PreserveWhitespace = true;
ProtectedConfigurationProvider.LoadXml(xmlDocument, "<foo>" + node.OuterXml + "</foo>");
exml = new EncryptedXml(xmlDocument);
inputElement = xmlDocument.DocumentElement;
using (SymmetricAlgorithm symAlg = GetSymAlgorithmProvider()) {
rgbOutput = exml.EncryptData(inputElement, symAlg, true);
ed = new EncryptedData();
ed.Type = EncryptedXml.XmlEncElementUrl;
ed.EncryptionMethod = GetSymEncryptionMethod();
ed.KeyInfo = new KeyInfo();
ek = new EncryptedKey();
ek.EncryptionMethod = new EncryptionMethod(UseOAEP ? EncryptedXml.XmlEncRSAOAEPUrl : EncryptedXml.XmlEncRSA15Url);
ek.KeyInfo = new KeyInfo();
ek.CipherData = new CipherData();
ek.CipherData.CipherValue = EncryptedXml.EncryptKey(symAlg.Key, rsa, UseOAEP);
}
kin = new KeyInfoName();
kin.Value = _KeyName;
ek.KeyInfo.AddClause(kin);
kek = new KeyInfoEncryptedKey(ek);
ed.KeyInfo.AddClause(kek);
ed.CipherData = new CipherData();
ed.CipherData.CipherValue = rgbOutput;
EncryptedXml.ReplaceElement(inputElement, ed, true);
rsa.Clear();
// Get node from the document
foreach (XmlNode node2 in xmlDocument.ChildNodes)
if (node2.NodeType == XmlNodeType.Element)
foreach (XmlNode node3 in node2.ChildNodes) // node2 is the "foo" node
if (node3.NodeType == XmlNodeType.Element)
return node3; // node3 is the "EncryptedData" node
return null;
}
public void AddKey(int keySize, bool exportable)
{
RSACryptoServiceProvider rsa = GetCryptoServiceProvider(exportable, false);
rsa.KeySize = keySize;
rsa.PersistKeyInCsp = true;
rsa.Clear();
}
public void DeleteKey()
{
RSACryptoServiceProvider rsa = GetCryptoServiceProvider(false, true);
rsa.PersistKeyInCsp = false;
rsa.Clear();
}
public void ImportKey(string xmlFileName, bool exportable)
{
RSACryptoServiceProvider rsa = GetCryptoServiceProvider(exportable, false);
rsa.FromXmlString(File.ReadAllText(xmlFileName));
rsa.PersistKeyInCsp = true;
rsa.Clear();
}
public void ExportKey(string xmlFileName, bool includePrivateParameters)
{
RSACryptoServiceProvider rsa = GetCryptoServiceProvider(false, false);
string xmlString = rsa.ToXmlString(includePrivateParameters);
File.WriteAllText(xmlFileName, xmlString);
rsa.Clear();
}
public string KeyContainerName { get { return _KeyContainerName; } }
public string CspProviderName { get { return _CspProviderName; } }
public bool UseMachineContainer { get { return _UseMachineContainer; } }
public bool UseOAEP { get { return _UseOAEP; } }
public bool UseFIPS { get { return _UseFIPS; } }
public override void Initialize(string name, NameValueCollection configurationValues)
{
base.Initialize(name, configurationValues);
_KeyName = "Rsa Key";
_KeyContainerName = configurationValues["keyContainerName"];
configurationValues.Remove("keyContainerName");
if (_KeyContainerName == null || _KeyContainerName.Length < 1)
_KeyContainerName = DefaultRsaKeyContainerName;
_CspProviderName = configurationValues["cspProviderName"];
configurationValues.Remove("cspProviderName");
_UseMachineContainer = GetBooleanValue(configurationValues, "useMachineContainer", true);
_UseOAEP = GetBooleanValue(configurationValues, "useOAEP", true);
_UseFIPS = GetBooleanValue(configurationValues, "useFIPS", true);
if (configurationValues.Count > 0)
throw new ConfigurationErrorsException(SR.GetString(SR.Unrecognized_initialization_value, configurationValues.GetKey(0)));
}
private string _KeyName;
private string _KeyContainerName;
private string _CspProviderName;
private bool _UseMachineContainer;
private bool _UseOAEP;
private bool _UseFIPS;
public RSAParameters RsaPublicKey { get { return GetCryptoServiceProvider(false, false).ExportParameters(false); } }
private RSACryptoServiceProvider GetCryptoServiceProvider(bool exportable, bool keyMustExist)
{
try {
CspParameters csp = new CspParameters();
csp.KeyContainerName = KeyContainerName;
csp.KeyNumber = 1;
csp.ProviderType = 1; // Dev10 Bug #548719: Explicitly require "RSA Full (Signature and Key Exchange)"
if (CspProviderName != null && CspProviderName.Length > 0)
csp.ProviderName = CspProviderName;
if (UseMachineContainer)
csp.Flags |= CspProviderFlags.UseMachineKeyStore;
if (!exportable && !keyMustExist)
csp.Flags |= CspProviderFlags.UseNonExportableKey;
if (keyMustExist)
csp.Flags |= CspProviderFlags.UseExistingKey;
return new RSACryptoServiceProvider(2048, csp);
} catch {
ThrowBetterException(keyMustExist);
// If a better exception can't be found, this will propagate
// the original one
throw;
}
}
private void ThrowBetterException(bool keyMustExist)
{
SafeCryptContextHandle hProv = null;
int success = 0;
try {
success = UnsafeNativeMethods.CryptAcquireContext(out hProv, KeyContainerName, CspProviderName, PROV_Rsa_FULL, UseMachineContainer ? CRYPT_MACHINE_KEYSET : 0);
if (success != 0)
return; // propagate original exception
int hr = Marshal.GetHRForLastWin32Error();
if (hr == HResults.NteBadKeySet && !keyMustExist) {
return; // propagate original exception
}
switch (hr) {
case HResults.NteBadKeySet:
case HResults.Win32AccessDenied:
case HResults.Win32InvalidHandle:
throw new ConfigurationErrorsException(SR.GetString(SR.Key_container_doesnt_exist_or_access_denied));
default:
Marshal.ThrowExceptionForHR(hr);
break;
}
} finally {
if (!(hProv == null || hProv.IsInvalid))
hProv.Dispose();
}
}
const uint PROV_Rsa_FULL = 1;
const uint CRYPT_MACHINE_KEYSET = 0x00000020;
private static bool GetBooleanValue(NameValueCollection configurationValues, string valueName, bool defaultValue) {
string s = configurationValues[valueName];
if (s == null)
return defaultValue;
configurationValues.Remove(valueName);
if (s == "true")
return true;
if (s == "false")
return false;
throw new ConfigurationErrorsException(SR.GetString(SR.Config_invalid_boolean_attribute, valueName));
}
[SuppressMessage("Microsoft.Cryptographic.Standard", "CA5353:TripleDESCannotBeUsed", Justification = @"AES is the default. For legacy compat, 3DES must be explicitly opted into.")]
private SymmetricAlgorithm GetSymAlgorithmProvider() {
SymmetricAlgorithm symAlg;
if (UseFIPS) {
// AesCryptoServiceProvider implementation is FIPS certified
symAlg = new AesCryptoServiceProvider();
}
else {
// Use the 3DES. FIPS obsolated 3DES
symAlg = new TripleDESCryptoServiceProvider();
}
return symAlg;
}
private EncryptionMethod GetSymEncryptionMethod() {
return UseFIPS ? new EncryptionMethod(EncryptedXml.XmlEncAES256Url) :
new EncryptionMethod(EncryptedXml.XmlEncTripleDESUrl);
}
}
}
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