2 // KeyPairPersistence.cs: Keypair persistence
5 // Sebastien Pouliot <sebastien@ximian.com>
7 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 #if !NET_2_1 || MONOTOUCH
32 using System
.Globalization
;
34 using System
.Runtime
.CompilerServices
;
35 using System
.Runtime
.InteropServices
;
36 using System
.Security
;
37 using System
.Security
.Cryptography
;
38 using System
.Security
.Permissions
;
43 namespace Mono
.Security
.Cryptography
{
46 * [type][unique name][key number].xml
49 * type CspParameters.ProviderType
50 * unique name A unique name for the keypair, which is
51 * a. default (for a provider default keypair)
52 * b. a GUID derived from
53 * i. random if no container name was
54 * specified at generation time
55 * ii. the MD5 hash of the container
56 * name (CspParameters.KeyContainerName)
57 * key number CspParameters.KeyNumber
62 * <Provider Name="" Type=""/>
63 * <Container Name=""/>
66 * RSAKeyValue, DSAKeyValue ...
73 * - There's NO confidentiality / integrity built in this
74 * persistance mechanism. The container directories (both user and
75 * machine) are created with restrited ACL. The ACL is also checked
76 * when a key is accessed (so totally public keys won't be used).
77 * see /mono/mono/metadata/security.c for implementation
79 * - As we do not use CSP we limit ourselves to provider types (not
80 * names). This means that for a same type and container type, but
81 * two different provider names) will return the same keypair. This
82 * should work as CspParameters always requires a csp type in its
85 * - Assert (CAS) are used so only the OS permission will limit access
86 * to the keypair files. I.e. this will work even in high-security
87 * scenarios where users do not have access to file system (e.g. web
88 * application). We can allow this because the filename used is
89 * TOTALLY under our control (no direct user input is used).
91 * - You CAN'T changes properties of the keypair once it's been
92 * created (saved). You must remove the container than save it
93 * back. This is the same behaviour as CSP under Windows.
101 class KeyPairPersistence
{
103 private static bool _userPathExists
= false; // check at 1st use
104 private static string _userPath
;
106 private static bool _machinePathExists
= false; // check at 1st use
107 private static string _machinePath
;
109 private CspParameters _params
;
110 private string _keyvalue
;
111 private string _filename
;
112 private string _container
;
116 public KeyPairPersistence (CspParameters parameters
)
117 : this (parameters
, null)
121 public KeyPairPersistence (CspParameters parameters
, string keyPair
)
123 if (parameters
== null)
124 throw new ArgumentNullException ("parameters");
126 _params
= Copy (parameters
);
132 public string Filename
{
134 if (_filename
== null) {
135 _filename
= String
.Format (CultureInfo
.InvariantCulture
,
136 "[{0}][{1}][{2}].xml",
137 _params
.ProviderType
,
140 if (UseMachineKeyStore
)
141 _filename
= Path
.Combine (MachinePath
, _filename
);
143 _filename
= Path
.Combine (UserPath
, _filename
);
149 public string KeyValue
{
150 get { return _keyvalue; }
157 // return a (read-only) copy
158 public CspParameters Parameters
{
159 get { return Copy (_params); }
167 // FIXME new FileIOPermission (FileIOPermissionAccess.Read, this.Filename).Assert ();
169 bool result
= File
.Exists (this.Filename
);
171 using (StreamReader sr
= File
.OpenText (this.Filename
)) {
172 FromXml (sr
.ReadToEnd ());
181 // FIXME new FileIOPermission (FileIOPermissionAccess.Write, this.Filename).Assert ();
183 using (FileStream fs
= File
.Open (this.Filename
, FileMode
.Create
)) {
184 StreamWriter sw
= new StreamWriter (fs
, Encoding
.UTF8
);
185 sw
.Write (this.ToXml ());
188 // apply protection to newly created files
189 if (UseMachineKeyStore
)
190 ProtectMachine (Filename
);
192 ProtectUser (Filename
);
195 public void Remove ()
198 // FIXME new FileIOPermission (FileIOPermissionAccess.Write, this.Filename).Assert ();
200 File
.Delete (this.Filename
);
201 // it's now possible to change the keypair un the container
204 // private static stuff
206 static object lockobj
= new object ();
208 private static string UserPath
{
211 if ((_userPath
== null) || (!_userPathExists
)) {
212 _userPath
= Path
.Combine (
213 Environment
.GetFolderPath (Environment
.SpecialFolder
.ApplicationData
),
215 _userPath
= Path
.Combine (_userPath
, "keypairs");
217 _userPathExists
= Directory
.Exists (_userPath
);
218 if (!_userPathExists
) {
220 Directory
.CreateDirectory (_userPath
);
221 ProtectUser (_userPath
);
222 _userPathExists
= true;
224 catch (Exception e
) {
225 string msg
= Locale
.GetText ("Could not create user key store '{0}'.");
226 throw new CryptographicException (String
.Format (msg
, _userPath
), e
);
231 // is it properly protected ?
232 if (!IsUserProtected (_userPath
)) {
233 string msg
= Locale
.GetText ("Improperly protected user's key pairs in '{0}'.");
234 throw new CryptographicException (String
.Format (msg
, _userPath
));
240 private static string MachinePath
{
243 if ((_machinePath
== null) || (!_machinePathExists
)) {
244 _machinePath
= Path
.Combine (
245 Environment
.GetFolderPath (Environment
.SpecialFolder
.CommonApplicationData
),
247 _machinePath
= Path
.Combine (_machinePath
, "keypairs");
249 _machinePathExists
= Directory
.Exists (_machinePath
);
250 if (!_machinePathExists
) {
252 Directory
.CreateDirectory (_machinePath
);
253 ProtectMachine (_machinePath
);
254 _machinePathExists
= true;
256 catch (Exception e
) {
257 string msg
= Locale
.GetText ("Could not create machine key store '{0}'.");
258 throw new CryptographicException (String
.Format (msg
, _machinePath
), e
);
263 // is it properly protected ?
264 if (!IsMachineProtected (_machinePath
)) {
265 string msg
= Locale
.GetText ("Improperly protected machine's key pairs in '{0}'.");
266 throw new CryptographicException (String
.Format (msg
, _machinePath
));
273 [MethodImplAttribute (MethodImplOptions
.InternalCall
)]
274 internal static extern bool _CanSecure (string root
);
276 [MethodImplAttribute (MethodImplOptions
.InternalCall
)]
277 internal static extern bool _ProtectUser (string path
);
279 [MethodImplAttribute (MethodImplOptions
.InternalCall
)]
280 internal static extern bool _ProtectMachine (string path
);
282 [MethodImplAttribute (MethodImplOptions
.InternalCall
)]
283 internal static extern bool _IsUserProtected (string path
);
285 [MethodImplAttribute (MethodImplOptions
.InternalCall
)]
286 internal static extern bool _IsMachineProtected (string path
);
288 // Mono.Security.dll assembly can't use the internal
289 // call (and still run with other runtimes)
291 // Note: Class is only available in Mono.Security.dll as
292 // a management helper (e.g. build a GUI app)
294 internal static bool _CanSecure (string root
)
299 internal static bool _ProtectUser (string path
)
304 internal static bool _ProtectMachine (string path
)
309 internal static bool _IsUserProtected (string path
)
314 internal static bool _IsMachineProtected (string path
)
321 private static bool CanSecure (string path
)
323 // we assume POSIX filesystems can always be secured
325 // check for Unix platforms - see FAQ for more details
326 // http://www.mono-project.com/FAQ:_Technical#How_to_detect_the_execution_platform_.3F
327 int platform
= (int) Environment
.OSVersion
.Platform
;
328 if ((platform
== 4) || (platform
== 128) || (platform
== 6))
331 // while we ask the runtime for Windows OS
332 return _CanSecure (Path
.GetPathRoot (path
));
335 private static bool ProtectUser (string path
)
337 // we cannot protect on some filsystem (like FAT)
338 if (CanSecure (path
)) {
339 return _ProtectUser (path
);
341 // but Mono still needs to run on them :(
345 private static bool ProtectMachine (string path
)
347 // we cannot protect on some filsystem (like FAT)
348 if (CanSecure (path
)) {
349 return _ProtectMachine (path
);
351 // but Mono still needs to run on them :(
355 private static bool IsUserProtected (string path
)
357 // we cannot protect on some filsystem (like FAT)
358 if (CanSecure (path
)) {
359 return _IsUserProtected (path
);
361 // but Mono still needs to run on them :(
365 private static bool IsMachineProtected (string path
)
367 // we cannot protect on some filsystem (like FAT)
368 if (CanSecure (path
)) {
369 return _IsMachineProtected (path
);
371 // but Mono still needs to run on them :(
375 private bool CanChange
{
376 get { return (_keyvalue == null); }
379 private bool UseDefaultKeyContainer
{
380 get { return ((_params.Flags & CspProviderFlags.UseDefaultKeyContainer) == CspProviderFlags.UseDefaultKeyContainer); }
383 private bool UseMachineKeyStore
{
384 get { return ((_params.Flags & CspProviderFlags.UseMachineKeyStore) == CspProviderFlags.UseMachineKeyStore); }
387 private string ContainerName
{
389 if (_container
== null) {
390 if (UseDefaultKeyContainer
) {
392 _container
= "default";
394 else if ((_params
.KeyContainerName
== null) || (_params
.KeyContainerName
.Length
== 0)) {
395 _container
= Guid
.NewGuid ().ToString ();
398 // we don't want to trust the key container name as we don't control it
399 // anyway some characters may not be compatible with the file system
400 byte[] data
= Encoding
.UTF8
.GetBytes (_params
.KeyContainerName
);
401 // Note: We use MD5 as it is faster than SHA1 and has the same length
402 // as a GUID. Recent problems found in MD5 (like collisions) aren't a
403 // problem in this case.
404 MD5 hash
= MD5
.Create ();
405 byte[] result
= hash
.ComputeHash (data
);
406 _container
= new Guid (result
).ToString ();
413 // we do not want any changes after receiving the csp informations
414 private CspParameters
Copy (CspParameters p
)
416 CspParameters copy
= new CspParameters (p
.ProviderType
, p
.ProviderName
, p
.KeyContainerName
);
417 copy
.KeyNumber
= p
.KeyNumber
;
418 copy
.Flags
= p
.Flags
;
422 private void FromXml (string xml
)
424 SecurityParser sp
= new SecurityParser ();
427 SecurityElement root
= sp
.ToXml ();
428 if (root
.Tag
== "KeyPair") {
429 //SecurityElement prop = root.SearchForChildByTag ("Properties");
430 SecurityElement keyv
= root
.SearchForChildByTag ("KeyValue");
431 if (keyv
.Children
.Count
> 0)
432 _keyvalue
= keyv
.Children
[0].ToString ();
433 // Note: we do not read other stuff because
434 // it can't be changed after key creation
438 private string ToXml ()
440 // note: we do not use SecurityElement here because the
441 // keypair is a XML string (requiring parsing)
442 StringBuilder xml
= new StringBuilder ();
443 xml
.AppendFormat ("<KeyPair>{0}\t<Properties>{0}\t\t<Provider ", Environment
.NewLine
);
444 if ((_params
.ProviderName
!= null) && (_params
.ProviderName
.Length
!= 0)) {
445 xml
.AppendFormat ("Name=\"{0}\" ", _params
.ProviderName
);
447 xml
.AppendFormat ("Type=\"{0}\" />{1}\t\t<Container ", _params
.ProviderType
, Environment
.NewLine
);
448 xml
.AppendFormat ("Name=\"{0}\" />{1}\t</Properties>{1}\t<KeyValue", this.ContainerName
, Environment
.NewLine
);
449 if (_params
.KeyNumber
!= -1) {
450 xml
.AppendFormat (" Id=\"{0}\" ", _params
.KeyNumber
);
452 xml
.AppendFormat (">{1}\t\t{0}{1}\t</KeyValue>{1}</KeyPair>{1}", this.KeyValue
, Environment
.NewLine
);
453 return xml
.ToString ();