Hex.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FXUpdate3074 / FXUpdate3074 / 1.1 / untmp / whidbey / QFE / ndp / clr / src / BCL / System / Security / Util / Hex.cs / 1 / Hex.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
/*
 * Hex.cs 
 * 
 * Operations to convert to and from Hex
 * 
 */

namespace System.Security.Util
{ 
    using System;
    using System.Security; 
    internal static class Hex 
    {
        // converts number to hex digit. Does not do any range checks. 
        static char HexDigit(int num) {
            return (char)((num < 10) ? (num + '0') : (num + ('A' - 10)));
        }
 
        public  static String EncodeHexString(byte[] sArray)
        { 
            String result = null; 

            if(sArray != null) { 
                char[] hexOrder = new char[sArray.Length * 2];

                int digit;
                for(int i = 0, j = 0; i < sArray.Length; i++) { 
                    digit = (int)((sArray[i] & 0xf0) >> 4);
                    hexOrder[j++] = HexDigit(digit); 
                    digit = (int)(sArray[i] & 0x0f); 
                    hexOrder[j++] = HexDigit(digit);
                } 
                result = new String(hexOrder);
            }
            return result;
        } 

        internal static string EncodeHexStringFromInt(byte[] sArray) { 
            String result = null; 
            if(sArray != null) {
                char[] hexOrder = new char[sArray.Length * 2]; 

                int i = sArray.Length;
                int digit, j=0;
                while (i-- > 0) { 
                    digit = (sArray[i] & 0xf0) >> 4;
                    hexOrder[j++] = HexDigit(digit); 
                    digit = sArray[i] & 0x0f; 
                    hexOrder[j++] = HexDigit(digit);
                } 
                result = new String(hexOrder);
            }
            return result;
        } 

        public static int ConvertHexDigit(Char val) 
        { 
            if (val <= '9' && val >= '0')
                return (val - '0'); 
            else if (val >= 'a' && val <= 'f')
                return ((val - 'a') + 10);
            else if (val >= 'A' && val <= 'F')
                return ((val - 'A') + 10); 
            else
                throw new ArgumentException( Environment.GetResourceString( "ArgumentOutOfRange_Index" ) ); 
        } 

 
        public static byte[] DecodeHexString(String hexString)
        {
            if (hexString == null)
                throw new ArgumentNullException( "hexString" ); 

            bool spaceSkippingMode = false; 
 
            int i = 0;
            int length = hexString.Length; 

            if ((length >= 2) &&
                (hexString[0] == '0') &&
                ( (hexString[1] == 'x') ||  (hexString[1] == 'X') )) 
            {
                length = hexString.Length - 2; 
                i = 2; 
            }
 
            // Hex strings must always have 2N or (3N - 1) entries.

            if (length % 2 != 0 && length % 3 != 2)
            { 
                throw new ArgumentException( Environment.GetResourceString( "Argument_InvalidHexFormat" ) );
            } 
 
            byte[] sArray;
 
            if (length >=3 && hexString[i + 2] == ' ')
            {
                spaceSkippingMode = true;
 
                // Each hex digit will take three spaces, except the first (hence the plus 1).
                sArray = new byte[length / 3 + 1]; 
            } 
            else
            { 
                // Each hex digit will take two spaces
                sArray = new byte[length / 2];
            }
 
            int digit;
            int rawdigit; 
            for (int j = 0; i < hexString.Length; i += 2, j++) { 
                rawdigit = ConvertHexDigit(hexString[i]);
                digit = ConvertHexDigit(hexString[i+1]); 
                sArray[j] = (byte) (digit | (rawdigit << 4));
                if (spaceSkippingMode)
                    i++;
            } 
            return(sArray);
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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