mcs/class/Mono.Security/Mono.Security.X509/X509Builder.cs

   1 //
   2 // X509Builder.cs: Abstract builder class for X509 objects
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
   8 // (C) 2004 Novell (http://www.novell.com)
   9 //
  10
  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 using System;
  33 using System.Globalization;
  34 using System.Security.Cryptography;
  35
  36 using Mono.Security;
  37
  38 namespace Mono.Security.X509 {
  39
  40         public abstract class X509Builder {
  41
  42                 private const string defaultHash = "SHA1";
  43                 private string hashName;
  44
  45                 protected X509Builder ()
  46                 {
  47                         hashName = defaultHash;
  48                 }
  49
  50                 protected abstract ASN1 ToBeSigned (string hashName);
  51
  52                 // move to PKCS1
  53                 protected string GetOid (string hashName)
  54                 {
  55                         switch (hashName.ToLower (CultureInfo.InvariantCulture)) {
  56                                 case "md2":
  57                                         // md2withRSAEncryption (1 2 840 113549 1 1 2)
  58                                         return "1.2.840.113549.1.1.2";
  59                                 case "md4":
  60                                         // md4withRSAEncryption (1 2 840 113549 1 1 3)
  61                                         return "1.2.840.113549.1.1.3";
  62                                 case "md5":
  63                                         // md5withRSAEncryption (1 2 840 113549 1 1 4)
  64                                         return "1.2.840.113549.1.1.4";
  65                                 case "sha1":
  66                                         // sha1withRSAEncryption (1 2 840 113549 1 1 5)
  67                                         return "1.2.840.113549.1.1.5";
  68                                 case "sha256":
  69                                         // sha256WithRSAEncryption      OBJECT IDENTIFIER ::= { pkcs-1 11 }
  70                                         return "1.2.840.113549.1.1.11";
  71                                 case "sha384":
  72                                         // sha384WithRSAEncryption      OBJECT IDENTIFIER ::= { pkcs-1 12 }
  73                                         return "1.2.840.113549.1.1.12";
  74                                 case "sha512":
  75                                         // sha512WithRSAEncryption      OBJECT IDENTIFIER ::= { pkcs-1 13 }
  76                                         return "1.2.840.113549.1.1.13";
  77                                 default:
  78                                         throw new NotSupportedException ("Unknown hash algorithm " + hashName);
  79                         }
  80                 }
  81
  82                 public string Hash {
  83                         get { return hashName; }
  84                         set {
  85                                 if (hashName == null)
  86                                         hashName = defaultHash;
  87                                 else
  88                                         hashName = value;
  89                         }
  90                 }
  91
  92                 public virtual byte[] Sign (AsymmetricAlgorithm aa)
  93                 {
  94                         if (aa is RSA)
  95                                 return Sign (aa as RSA);
  96                         else if (aa is DSA)
  97                                 return Sign (aa as DSA);
  98                         else
  99                                 throw new NotSupportedException ("Unknown Asymmetric Algorithm " + aa.ToString());
 100                 }
 101
 102                 private byte[] Build (ASN1 tbs, string hashoid, byte[] signature)
 103                 {
 104                         ASN1 builder = new ASN1 (0x30);
 105                         builder.Add (tbs);
 106                         builder.Add (PKCS7.AlgorithmIdentifier (hashoid));
 107                         // first byte of BITSTRING is the number of unused bits in the first byte
 108                         byte[] bitstring = new byte [signature.Length + 1];
 109                         Buffer.BlockCopy (signature, 0, bitstring, 1, signature.Length);
 110                         builder.Add (new ASN1 (0x03, bitstring));
 111                         return builder.GetBytes ();
 112                 }
 113
 114                 public virtual byte[] Sign (RSA key)
 115                 {
 116                         string oid = GetOid (hashName);
 117                         ASN1 tbs = ToBeSigned (oid);
 118                         HashAlgorithm ha = HashAlgorithm.Create (hashName);
 119                         byte[] hash = ha.ComputeHash (tbs.GetBytes ());
 120
 121                         RSAPKCS1SignatureFormatter pkcs1 = new RSAPKCS1SignatureFormatter (key);
 122                         pkcs1.SetHashAlgorithm (hashName);
 123                         byte[] signature = pkcs1.CreateSignature (hash);
 124
 125                         return Build (tbs, oid, signature);
 126                 }
 127
 128                 public virtual byte[] Sign (DSA key)
 129                 {
 130                         string oid = "1.2.840.10040.4.3";
 131                         ASN1 tbs = ToBeSigned (oid);
 132                         HashAlgorithm ha = HashAlgorithm.Create (hashName);
 133                         if (!(ha is SHA1))
 134                                 throw new NotSupportedException ("Only SHA-1 is supported for DSA");
 135                         byte[] hash = ha.ComputeHash (tbs.GetBytes ());
 136
 137                         DSASignatureFormatter dsa = new DSASignatureFormatter (key);
 138                         dsa.SetHashAlgorithm (hashName);
 139                         byte[] rs = dsa.CreateSignature (hash);
 140
 141                         // split R and S
 142                         byte[] r = new byte [20];
 143                         Buffer.BlockCopy (rs, 0, r, 0, 20);
 144                         byte[] s = new byte [20];
 145                         Buffer.BlockCopy (rs, 20, s, 0, 20);
 146                         ASN1 signature = new ASN1 (0x30);
 147                         signature.Add (new ASN1 (0x02, r));
 148                         signature.Add (new ASN1 (0x02, s));
 149
 150                         // dsaWithSha1 (1 2 840 10040 4 3)
 151                         return Build (tbs, oid, signature.GetBytes ());
 152                 }
 153         }
 154 }