RSAPKCS1KeyExchangeFormatter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / Security / Cryptography / RSAPKCS1KeyExchangeFormatter.cs / 1305376 / RSAPKCS1KeyExchangeFormatter.cs
                        
                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
// [....]
// 
 
namespace System.Security.Cryptography {
    using System.Globalization; 
    using System.Diagnostics.Contracts;

    [System.Runtime.InteropServices.ComVisible(true)]
    public class RSAPKCS1KeyExchangeFormatter : AsymmetricKeyExchangeFormatter { 
        RandomNumberGenerator RngValue;
        RSA _rsaKey; 
 
        //
        // public constructors 
        //

        public RSAPKCS1KeyExchangeFormatter() {}
 
        public RSAPKCS1KeyExchangeFormatter(AsymmetricAlgorithm key) {
            if (key == null) 
                throw new ArgumentNullException("key"); 
            Contract.EndContractBlock();
            _rsaKey = (RSA) key; 
        }

        //
        // public properties 
        //
 
        public override String Parameters { 
            get { return ""; }
        } 

        public RandomNumberGenerator Rng {
            get { return RngValue; }
            set { RngValue = value; } 
        }
 
        // 
        // public methods
        // 

        public override void SetKey(AsymmetricAlgorithm key) {
            if (key == null)
                throw new ArgumentNullException("key"); 
            Contract.EndContractBlock();
            _rsaKey = (RSA) key; 
        } 

        [System.Security.SecuritySafeCritical]  // auto-generated 
        public override byte[] CreateKeyExchange(byte[] rgbData) {
            if (_rsaKey == null)
                throw new CryptographicUnexpectedOperationException(Environment.GetResourceString("Cryptography_MissingKey"));
 
            byte[] rgbKeyEx;
            if (_rsaKey is RSACryptoServiceProvider) { 
                rgbKeyEx = ((RSACryptoServiceProvider) _rsaKey).Encrypt(rgbData, false); 
            }
            else { 
                int cb = _rsaKey.KeySize/8;
                if ((rgbData.Length + 11) > cb)
                    throw new CryptographicException(Environment.GetResourceString("Cryptography_Padding_EncDataTooBig", cb-11));
                byte[]  rgbInput = new byte[cb]; 

                // 
                //  We want to pad to the following format: 
                //      00 || 02 || PS || 00 || D
                // 
                //      PS - pseudorandom non zero bytes
                //      D - data
                //
 
                if (RngValue == null) {
                    RngValue = RandomNumberGenerator.Create(); 
                } 

                Rng.GetNonZeroBytes(rgbInput); 
                rgbInput[0] = 0;
                rgbInput[1] = 2;
                rgbInput[cb-rgbData.Length-1] = 0;
                Buffer.InternalBlockCopy(rgbData, 0, rgbInput, cb-rgbData.Length, rgbData.Length); 

                // 
                //  Now encrypt the value and return it. (apply public key) 
                //
 
                rgbKeyEx = _rsaKey.EncryptValue(rgbInput);
            }
            return rgbKeyEx;
        } 

        public override byte[] CreateKeyExchange(byte[] rgbData, Type symAlgType) { 
            return CreateKeyExchange(rgbData); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
// [....]
// 
 
namespace System.Security.Cryptography {
    using System.Globalization; 
    using System.Diagnostics.Contracts;

    [System.Runtime.InteropServices.ComVisible(true)]
    public class RSAPKCS1KeyExchangeFormatter : AsymmetricKeyExchangeFormatter { 
        RandomNumberGenerator RngValue;
        RSA _rsaKey; 
 
        //
        // public constructors 
        //

        public RSAPKCS1KeyExchangeFormatter() {}
 
        public RSAPKCS1KeyExchangeFormatter(AsymmetricAlgorithm key) {
            if (key == null) 
                throw new ArgumentNullException("key"); 
            Contract.EndContractBlock();
            _rsaKey = (RSA) key; 
        }

        //
        // public properties 
        //
 
        public override String Parameters { 
            get { return ""; }
        } 

        public RandomNumberGenerator Rng {
            get { return RngValue; }
            set { RngValue = value; } 
        }
 
        // 
        // public methods
        // 

        public override void SetKey(AsymmetricAlgorithm key) {
            if (key == null)
                throw new ArgumentNullException("key"); 
            Contract.EndContractBlock();
            _rsaKey = (RSA) key; 
        } 

        [System.Security.SecuritySafeCritical]  // auto-generated 
        public override byte[] CreateKeyExchange(byte[] rgbData) {
            if (_rsaKey == null)
                throw new CryptographicUnexpectedOperationException(Environment.GetResourceString("Cryptography_MissingKey"));
 
            byte[] rgbKeyEx;
            if (_rsaKey is RSACryptoServiceProvider) { 
                rgbKeyEx = ((RSACryptoServiceProvider) _rsaKey).Encrypt(rgbData, false); 
            }
            else { 
                int cb = _rsaKey.KeySize/8;
                if ((rgbData.Length + 11) > cb)
                    throw new CryptographicException(Environment.GetResourceString("Cryptography_Padding_EncDataTooBig", cb-11));
                byte[]  rgbInput = new byte[cb]; 

                // 
                //  We want to pad to the following format: 
                //      00 || 02 || PS || 00 || D
                // 
                //      PS - pseudorandom non zero bytes
                //      D - data
                //
 
                if (RngValue == null) {
                    RngValue = RandomNumberGenerator.Create(); 
                } 

                Rng.GetNonZeroBytes(rgbInput); 
                rgbInput[0] = 0;
                rgbInput[1] = 2;
                rgbInput[cb-rgbData.Length-1] = 0;
                Buffer.InternalBlockCopy(rgbData, 0, rgbInput, cb-rgbData.Length, rgbData.Length); 

                // 
                //  Now encrypt the value and return it. (apply public key) 
                //
 
                rgbKeyEx = _rsaKey.EncryptValue(rgbInput);
            }
            return rgbKeyEx;
        } 

        public override byte[] CreateKeyExchange(byte[] rgbData, Type symAlgType) { 
            return CreateKeyExchange(rgbData); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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RSAPKCS1KeyExchangeFormatter.cs source code in C# .NET

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