rsa.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / clr / src / BCL / System / Security / Cryptography / rsa.cs / 1 / rsa.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 

// 
//  RSA.cs 
//
 
namespace System.Security.Cryptography {
    using System.Text;
    using System.Runtime.Serialization;
    using System.Security.Util; 
    using System.Globalization;
 
    // We allow only the public components of an RSAParameters object, the Modulus and Exponent 
    // to be serializable.
    [Serializable] 
[System.Runtime.InteropServices.ComVisible(true)]
    public struct RSAParameters {
        public byte[]      Exponent;
        public byte[]      Modulus; 
        [NonSerialized] public byte[]      P;
        [NonSerialized] public byte[]      Q; 
        [NonSerialized] public byte[]      DP; 
        [NonSerialized] public byte[]      DQ;
        [NonSerialized] public byte[]      InverseQ; 
        [NonSerialized] public byte[]      D;
    }

[System.Runtime.InteropServices.ComVisible(true)] 
    public abstract class RSA : AsymmetricAlgorithm
    { 
        // 
        //  Extending this class allows us to know that you are really implementing
        //  an RSA key.  This is required for anybody providing a new RSA key value 
        //  implemention.
        //
        //  The class provides no methods, fields or anything else.  Its only purpose is
        //  as a heirarchy member for identification of algorithm. 
        //
 
        protected RSA() { } 

        // 
        // public methods
        //

        new static public RSA Create() { 
            return Create("System.Security.Cryptography.RSA");
        } 
 
        new static public RSA Create(String algName) {
            return (RSA) CryptoConfig.CreateFromName(algName); 
        }

        // Apply the private key to the data.  This function represents a
        // raw RSA operation -- no implicit depadding of the imput value 
        abstract public byte[] DecryptValue(byte[] rgb);
 
        // Apply the public key to the data.  Again, this is a raw operation, no 
        // automatic padding.
        abstract public byte[] EncryptValue(byte[] rgb); 

        // Import/export functions

        // We can provide a default implementation of FromXmlString because we require 
        // every RSA implementation to implement ImportParameters
        // All we have to do here is parse the XML. 
 
        public override void FromXmlString(String xmlString) {
            if (xmlString == null) throw new ArgumentNullException("xmlString"); 
            RSAParameters rsaParams = new RSAParameters();
            Parser p = new Parser(xmlString);
            SecurityElement topElement = p.GetTopElement();
 
            // Modulus is always present
            String modulusString = topElement.SearchForTextOfLocalName("Modulus"); 
            if (modulusString == null) { 
                throw new CryptographicException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Cryptography_InvalidFromXmlString"),"RSA","Modulus"));
            } 
            rsaParams.Modulus = Convert.FromBase64String(Utils.DiscardWhiteSpaces(modulusString));

            // Exponent is always present
            String exponentString = topElement.SearchForTextOfLocalName("Exponent"); 
            if (exponentString == null) {
                throw new CryptographicException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Cryptography_InvalidFromXmlString"),"RSA","Exponent")); 
            } 
            rsaParams.Exponent = Convert.FromBase64String(Utils.DiscardWhiteSpaces(exponentString));
 
            // P is optional
            String pString = topElement.SearchForTextOfLocalName("P");
            if (pString != null) rsaParams.P = Convert.FromBase64String(Utils.DiscardWhiteSpaces(pString));
 
            // Q is optional
            String qString = topElement.SearchForTextOfLocalName("Q"); 
            if (qString != null) rsaParams.Q = Convert.FromBase64String(Utils.DiscardWhiteSpaces(qString)); 

            // DP is optional 
            String dpString = topElement.SearchForTextOfLocalName("DP");
            if (dpString != null) rsaParams.DP = Convert.FromBase64String(Utils.DiscardWhiteSpaces(dpString));

            // DQ is optional 
            String dqString = topElement.SearchForTextOfLocalName("DQ");
            if (dqString != null) rsaParams.DQ = Convert.FromBase64String(Utils.DiscardWhiteSpaces(dqString)); 
 
            // InverseQ is optional
            String inverseQString = topElement.SearchForTextOfLocalName("InverseQ"); 
            if (inverseQString != null) rsaParams.InverseQ = Convert.FromBase64String(Utils.DiscardWhiteSpaces(inverseQString));

            // D is optional
            String dString = topElement.SearchForTextOfLocalName("D"); 
            if (dString != null) rsaParams.D = Convert.FromBase64String(Utils.DiscardWhiteSpaces(dString));
 
            ImportParameters(rsaParams); 
        }
 
        // We can provide a default implementation of ToXmlString because we require
        // every RSA implementation to implement ImportParameters
        // If includePrivateParameters is false, this is just an XMLDSIG RSAKeyValue
        // clause.  If includePrivateParameters is true, then we extend RSAKeyValue with 
        // the other (private) elements.
        public override String ToXmlString(bool includePrivateParameters) { 
            // From the XMLDSIG spec, RFC 3075, Section 6.4.2, an RSAKeyValue looks like this: 
            /*
                
                 
                   
                     
                      
                   
                  
                
            */
            // we extend appropriately for private components 
            RSAParameters rsaParams = this.ExportParameters(includePrivateParameters);
            StringBuilder sb = new StringBuilder();
            sb.Append("");
            // Add the modulus 
            sb.Append(""+Convert.ToBase64String(rsaParams.Modulus)+"");
            // Add the exponent 
            sb.Append(""+Convert.ToBase64String(rsaParams.Exponent)+""); 
            if (includePrivateParameters) {
                // Add the private components 
                sb.Append("
"+Convert.ToBase64String(rsaParams.P)+"
");
                sb.Append(""+Convert.ToBase64String(rsaParams.Q)+"");
                sb.Append(""+Convert.ToBase64String(rsaParams.DP)+"");
                sb.Append(""+Convert.ToBase64String(rsaParams.DQ)+""); 
                sb.Append(""+Convert.ToBase64String(rsaParams.InverseQ)+"");
                sb.Append(""+Convert.ToBase64String(rsaParams.D)+""); 
            } 
            sb.Append("");
            return(sb.ToString()); 
        }

        abstract public RSAParameters ExportParameters(bool includePrivateParameters);
 
        abstract public void ImportParameters(RSAParameters parameters);
    } 
}

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