mcs/class/corlib/System.Security.Cryptography/CryptoConfig_2_1.cs

   1 //
   2 // CryptoConfig.cs: Handles cryptographic implementations and OIDs mappings.
   3 //
   4 // Author:
   5 //      Sebastien Pouliot (sebastien@ximian.com)
   6 //      Tim Coleman (tim@timcoleman.com)
   7 //
   8 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
   9 // Copyright (C) Tim Coleman, 2004
  10 // Copyright (C) 2004-2007, 2009 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 namespace System.Security.Cryptography {
  33
  34         public partial class CryptoConfig {
  35
  36                 public static byte[] EncodeOID (string str)
  37                 {
  38                         if (str == null)
  39                                 throw new ArgumentNullException ("str");
  40                         char[] delim = { '.' };
  41                         string[] parts = str.Split (delim);
  42                         // according to X.208 n is always at least 2
  43                         if (parts.Length < 2) {
  44                                 throw new CryptographicUnexpectedOperationException (
  45                                         Locale.GetText ("OID must have at least two parts"));
  46                         }
  47
  48                         // we're sure that the encoded OID is shorter than its string representation
  49                         byte[] oid = new byte [str.Length];
  50                         // now encoding value
  51                         try {
  52                                 byte part0 = Convert.ToByte (parts [0]);
  53                                 // OID[0] > 2 is invalid but "supported" in MS BCL
  54                                 // uncomment next line to trap this error
  55                                 // if (part0 > 2) throw new CryptographicUnexpectedOperationException ();
  56                                 byte part1 = Convert.ToByte (parts [1]);
  57                                 // OID[1] >= 40 is illegal for OID[0] < 2 because of the % 40
  58                                 // however the syntax is "supported" in MS BCL
  59                                 // uncomment next 2 lines to trap this error
  60                                 //if ((part0 < 2) && (part1 >= 40))
  61                                 //      throw new CryptographicUnexpectedOperationException ();
  62                                 oid[2] = Convert.ToByte (part0 * 40 + part1);
  63                         }
  64                         catch {
  65                                 throw new CryptographicUnexpectedOperationException (
  66                                         Locale.GetText ("Invalid OID"));
  67                         }
  68                         int j = 3;
  69                         for (int i = 2; i < parts.Length; i++) {
  70                                 long x = Convert.ToInt64 (parts [i]);
  71                                 if (x > 0x7F) {
  72                                         byte[] num = EncodeLongNumber (x);
  73                                         Buffer.BlockCopy (num, 0, oid, j, num.Length);
  74                                         j += num.Length;
  75                                 }
  76                                 else
  77                                         oid[j++] = Convert.ToByte (x);
  78                         }
  79
  80                         int k = 2;
  81                         // copy the exact number of byte required
  82                         byte[] oid2 = new byte [j];
  83                         oid2[0] = 0x06; // always - this tag means OID
  84                         // Length (of value)
  85                         if (j > 0x7F) {
  86                                 // for compatibility with MS BCL
  87                                 throw new CryptographicUnexpectedOperationException (
  88                                         Locale.GetText ("OID > 127 bytes"));
  89                                 // comment exception and uncomment next 3 lines to remove restriction
  90                                 //byte[] num = EncodeLongNumber (j);
  91                                 //Buffer.BlockCopy (num, 0, oid, j, num.Length);
  92                                 //k = num.Length + 1;
  93                         }
  94                         else
  95                                 oid2 [1] = Convert.ToByte (j - 2);
  96
  97                         Buffer.BlockCopy (oid, k, oid2, k, j - k);
  98                         return oid2;
  99                 }
 100
 101                 // encode (7bits array) number greater than 127
 102                 private static byte[] EncodeLongNumber (long x)
 103                 {
 104                         // for MS BCL compatibility
 105                         // comment next two lines to remove restriction
 106                         if ((x > Int32.MaxValue) || (x < Int32.MinValue))
 107                                 throw new OverflowException (Locale.GetText ("Part of OID doesn't fit in Int32"));
 108
 109                         long y = x;
 110                         // number of bytes required to encode this number
 111                         int n = 1;
 112                         while (y > 0x7F) {
 113                                 y = y >> 7;
 114                                 n++;
 115                         }
 116                         byte[] num = new byte [n];
 117                         // encode all bytes
 118                         for (int i = 0; i < n; i++) {
 119                                 y = x >> (7 * i);
 120                                 y = y & 0x7F;
 121                                 if (i != 0)
 122                                         y += 0x80;
 123                                 num[n-i-1] = Convert.ToByte (y);
 124                         }
 125                         return num;
 126                 }
 127 #if MOONLIGHT
 128                 // we need SHA1 support to verify the codecs binary integrity
 129                 public static string MapNameToOID (string name)
 130                 {
 131                         if ((name != null) && name.Contains ("SHA1"))
 132                                 return "1.3.14.3.2.26";
 133                         return String.Empty;
 134                 }
 135
 136                 // non-configurable (versus machine.config) mappings for Moonlight (to avoid loading custom code)
 137                 public static object CreateFromName (string name)
 138                 {
 139                         switch (name) {
 140                         case "System.Security.Cryptography.HashAlgorithm":
 141                         case "System.Security.Cryptography.SHA1":
 142                         case "SHA1":
 143                                 return new SHA1Managed ();
 144                         case "SHA256":
 145                                 return new SHA256Managed ();
 146                         case "System.Security.Cryptography.MD5":
 147                         case "MD5":
 148                                 return new MD5CryptoServiceProvider ();
 149                         case "System.Security.Cryptography.RandomNumberGenerator":
 150                                 return new RNGCryptoServiceProvider ();
 151                         case "System.Security.Cryptography.RSA":
 152                                 return new Mono.Security.Cryptography.RSAManaged ();
 153                         default:
 154                                 throw new NotImplementedException (name);
 155                         }
 156                 }
 157 #endif
 158         }
 159 }
 160