2 // System.Security.Cryptography.DSA.cs class implementation
5 // Thomas Neidhart (tome@sbox.tugraz.at)
6 // Sebastien Pouliot (sebastien@ximian.com)
8 // Portions (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
9 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
32 using System
.Globalization
;
39 // a. FIPS PUB 186-2: Digital Signature Standard (DSS)
40 // http://csrc.nist.gov/publications/fips/fips186-2/fips186-2-change1.pdf
42 namespace System
.Security
.Cryptography
{
44 public abstract class DSA
: AsymmetricAlgorithm
{
47 // Constructor visibility fixed in Fx 2.0
50 // LAMESPEC: It says to derive new DSA implemenation from DSA class.
51 // Well it's aint gonna be easy this way.
52 // RSA constructor is public
58 public static new DSA
Create ()
60 return Create ("System.Security.Cryptography.DSA");
63 public static new DSA
Create (string algName
)
65 return (DSA
) CryptoConfig
.CreateFromName (algName
);
68 public abstract byte[] CreateSignature (byte[] rgbHash
);
70 public abstract DSAParameters
ExportParameters (bool includePrivateParameters
);
72 internal void ZeroizePrivateKey (DSAParameters parameters
)
74 if (parameters
.X
!= null)
75 Array
.Clear (parameters
.X
, 0, parameters
.X
.Length
);
78 private byte[] GetNamedParam (SecurityElement se
, string param
)
80 SecurityElement sep
= se
.SearchForChildByTag (param
);
83 return Convert
.FromBase64String (sep
.Text
);
86 public override void FromXmlString (string xmlString
)
88 if (xmlString
== null)
89 throw new ArgumentNullException ("xmlString");
91 DSAParameters dsaParams
= new DSAParameters ();
93 SecurityParser sp
= new SecurityParser ();
94 sp
.LoadXml (xmlString
);
95 SecurityElement se
= sp
.ToXml ();
96 if (se
.Tag
!= "DSAKeyValue")
97 throw new Exception ();
98 dsaParams
.P
= GetNamedParam (se
, "P");
99 dsaParams
.Q
= GetNamedParam (se
, "Q");
100 dsaParams
.G
= GetNamedParam (se
, "G");
101 dsaParams
.J
= GetNamedParam (se
, "J");
102 dsaParams
.Y
= GetNamedParam (se
, "Y");
103 dsaParams
.X
= GetNamedParam (se
, "X");
104 dsaParams
.Seed
= GetNamedParam (se
, "Seed");
105 byte[] counter
= GetNamedParam (se
, "PgenCounter");
106 if (counter
!= null) {
107 byte[] counter4b
= new byte [4]; // always 4 bytes
108 Buffer
.BlockCopy (counter
, 0, counter4b
, 0, counter
.Length
);
109 dsaParams
.Counter
= BitConverterLE
.ToInt32 (counter4b
, 0);
111 ImportParameters (dsaParams
);
114 ZeroizePrivateKey (dsaParams
);
118 ZeroizePrivateKey (dsaParams
);
122 public abstract void ImportParameters (DSAParameters parameters
);
124 // note: using SecurityElement.ToXml wouldn't generate the same string as the MS implementation
125 public override string ToXmlString (bool includePrivateParameters
)
127 StringBuilder sb
= new StringBuilder ();
128 DSAParameters dsaParams
= ExportParameters (includePrivateParameters
);
130 sb
.Append ("<DSAKeyValue>");
133 sb
.Append (Convert
.ToBase64String (dsaParams
.P
));
137 sb
.Append (Convert
.ToBase64String (dsaParams
.Q
));
141 sb
.Append (Convert
.ToBase64String (dsaParams
.G
));
145 sb
.Append (Convert
.ToBase64String (dsaParams
.Y
));
149 sb
.Append (Convert
.ToBase64String (dsaParams
.J
));
152 if (dsaParams
.Seed
!= null) {
153 sb
.Append ("<Seed>");
154 sb
.Append (Convert
.ToBase64String (dsaParams
.Seed
));
155 sb
.Append ("</Seed>");
157 sb
.Append ("<PgenCounter>");
158 // the number of bytes is important (no matter == 0x00)
159 byte[] inArr
= BitConverterLE
.GetBytes (dsaParams
.Counter
);
160 int l
= inArr
.Length
;
161 while (inArr
[l
-1] == 0x00)
163 byte[] c
= new byte [l
];
164 Buffer
.BlockCopy (inArr
, 0, c
, 0, l
);
165 sb
.Append (Convert
.ToBase64String (c
));
166 sb
.Append ("</PgenCounter>");
169 if (dsaParams
.X
!= null) {
171 sb
.Append (Convert
.ToBase64String (dsaParams
.X
));
174 else if (includePrivateParameters
) {
175 throw new CryptographicException (
176 Locale
.GetText ("Missing private key informations"));
179 sb
.Append ("</DSAKeyValue>");
182 ZeroizePrivateKey (dsaParams
);
186 return sb
.ToString ();
189 public abstract bool VerifySignature (byte[] rgbHash
, byte[] rgbSignature
);