How to encode text in C#? - c#

I faced a question in an interview test but i got confused and didnt answer that.Can anyone tell me how to encode a text in C#?
The question is :
How to encode a following text
a. U0VDUkVUIENPREUgSVMgTkVYR0VOIElTIFRFU1RJTkc=
I tried following code on my own just for try but didnt get any good output:
static void Main(string[] args)
{
string str= "U0VDUkVUIENPREUgSVMgTkVYR0VOIElTIFRFU1RJTkc=";
byte[] _telnetData;
_telnetData = new byte[1024];
_telnetData = Encoding.ASCII.GetBytes(str);
Console.WriteLine(_telnetData);
// _networkstream.Write(_telnetData, 0, _telnetData.Length);
Console.ReadLine();
}
I got following output:
Any help would be highly appreciable.

That is Base64 encoded text, so you should use Convert.ToBase64String(byte[]).
string text = "SECRET CODE IS NEXGEN IS TESTING";
Console.WriteLine(Convert.ToBase64String(Encoding.UTF8.GetBytes(text)));
The dead giveaway is the characters not being limited to A-F and 0-9, the "=" on the end is not always present, but further suggests base64.

You already encoded it with this line
telnetData = Encoding.ASCII.GetBytes(str);
Now you have the encoded text in a byte array. By definition encoding is converting text to byte array containing the appropriate byte values for the current text.

Related

String path to base64string

Im having a problem generating a base64string with a specific encoder.
I have an application that generate this base64string
RQA6AFwAUAByAG8AagBlAGMAdABzAFwAWQBvAHUAdAB1AGIAZQAuAE0AYQBuAGEAZwBlAHIAXABZAG8AdQB0AHUAYgBlAC4ATQBhAG4AYQBnAGUAcgAuAE0AbwBkAGUAbABzAC4AQwBvAG4AdABhAGkAbgBlAHIAXABvAGIAagBcAFIAZQBsAGUAYQBzAGUAXABuAGUAdABzAHQAYQBuAGQAYQByAGQAMgAuADAAXABZAG8AdQB0AHUAYgBlAC4ATQBhAG4AYQBnAGUAcgAuAE0AbwBkAGUAbABzAC4AQwBvAG4AdABhAGkAbgBlAHIALgBkAGwAbAAAAA==
which is equal to
E:\Projects\Youtube.Manager\Youtube.Manager.Models.Container\obj\Release\netstandard2.0\Youtube.Manager.Models.Container.dll
Now im trying convert
E:\Projects\Youtube.Manager\Youtube.Manager.Models.Container\obj\Release\netstandard2.0\Youtube.Manager.Models.Container.dll
To base64string but im getting this instead
RTpcUHJvamVjdHNcWW91dHViZS5NYW5hZ2VyXFlvdXR1YmUuTWFuYWdlci5Nb2RlbHMuQ29udGFpbmVyXG9ialxSZWxlYXNlXG5ldHN0YW5kYXJkMi4wXFlvdXR1YmUuTWFuYWdlci5Nb2RlbHMuQ29udGFpbmVyLmRsbA==
I want to get the same result as the first base64string which is
RQA6AFwAUAByAG8AagBlAGMAdABzAFwAWQBvAHUAdAB1AGIAZQAuAE0AYQBuAGEAZwBlAHIAXABZAG8AdQB0AHUAYgBlAC4ATQBhAG4AYQBnAGUAcgAuAE0AbwBkAGUAbABzAC4AQwBvAG4AdABhAGkAbgBlAHIAXABvAGIAagBcAFIAZQBsAGUAYQBzAGUAXABuAGUAdABzAHQAYQBuAGQAYQByAGQAMgAuADAAXABZAG8AdQB0AHUAYgBlAC4ATQBhAG4AYQBnAGUAcgAuAE0AbwBkAGUAbABzAC4AQwBvAG4AdABhAGkAbgBlAHIALgBkAGwAbAAAAA==
How can i do it?
This is my code which is giving me a wrong result
var bytes= Encoding.ASCII.GetBytes(msg);
return Convert.ToBase64String(bytes);
The problem here is the text encoding you're using.
The first Base64 string you posted is encoded using Unicode with a nul terminator byte pair. The trailing 'AAAAA==' is a dead giveaway here. You can see it yourself by examining the byte array:
var originalB64 = "RQA6AFwAUAByAG8AagBlAGMAdABzAFwAWQBvAHUAdAB1AGIAZQAuAE0AYQBuAGEAZwBlAHIAXABZAG8AdQB0AHUAYgBlAC4ATQBhAG4AYQBnAGUAcgAuAE0AbwBkAGUAbABzAC4AQwBvAG4AdABhAGkAbgBlAHIAXABvAGIAagBcAFIAZQBsAGUAYQBzAGUAXABuAGUAdABzAHQAYQBuAGQAYQByAGQAMgAuADAAXABZAG8AdQB0AHUAYgBlAC4ATQBhAG4AYQBnAGUAcgAuAE0AbwBkAGUAbABzAC4AQwBvAG4AdABhAGkAbgBlAHIALgBkAGwAbAAAAA==";
var bytes = Convert.FromBase64String(originalB64);
Converting this to a string will give you a null-terminated string 125 characters long, with the last character being nul.
Given a path that is not nul-terminated you can reproduce that string as follows:
string path = #"E:\Projects\Youtube.Manager\Youtube.Manager.Models.Container\obj\Release\netstandard2.0\Youtube.Manager.Models.Container.dll";
string newB64 = Convert.ToBase64String(Encoding.Unicode.GetBytes(path + "\0"));
This matches the original Base64 string exactly in my tests.

C# Encoding from utf-16 to ascii

I get question marks in output of my program: ?????? ??????
string str = "Привет медвед";
Encoding srcEncodingFormat = Encoding.GetEncoding("utf-16");
Encoding dstEncodingFormat = Encoding.ASCII;
byte [] originalByteString = srcEncodingFormat.GetBytes(str);
byte [] convertedByteString = Encoding.Convert(srcEncodingFormat,
dstEncodingFormat, originalByteString);
string finalString = dstEncodingFormat.GetString(convertedByteString);
Console.WriteLine (finalString);
There is no text but encoded text. But, .NET's char and string use Unicode/UTF-16, as you know. So, you can simplify your code by calling GetBytes and passing in the string instead of doing it twice as your code does.
As for your question, you have a choice of a lossy conversion or no conversion at all. Below is code that prevents a lossy conversion.
Now, how to see the result? As with all text, it is a sequence of bytes. Your best bet is to write them to a file and open the file in an editor that you can indicate the encoding to and that can use a font that supports the characters you want to see.
string str = "Привет медвед";
Encoding dstEncodingFormat = Encoding.GetEncoding("US-ASCII",
new EncoderExceptionFallback(),
new DecoderReplacementFallback());
byte[] output = dstEncodingFormat.GetBytes(str);
File.WriteAllBytes("Test Привет медвед.txt", output);

Understand how to decode this base64 encoded string

I've handled base64 encoded images and strings and have been able to decode them using C# in the past.
I'm now trying on what looks to me like a base64 string, but the value I'm getting is about 98% accurate and I just don't understand what is affecting the output.
Here is the string:
http://pastebin.com/ntcth6uN
And this is the decoded value:
http://pastebin.com/Buh4xXDA
That IS what it should be, but you can clearly see where there are artifacts and the decoded value isn't quite right.
Any idea why it's failing?
var data = Convert.FromBase64String(Faces[i].InfoData);
Faces[i].InfoData = Encoding.UTF8.GetString(data);
Thanks for your help.
The string is not encoded as UTF8, but instead as another encoding. Thus the same encoding must be used to decode it.
Use the following to decode it:
Encoding.ASCII.GetString(data);
If ASCII isn't the correct encoding, here's some code that will iterate through available encodings and list the first 200 characters in order to manually select original encoding:
String encStr = "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";
var data = Convert.FromBase64String(encStr);
// Iterate over all encodings, and decode
foreach (EncodingInfo ei in Encoding.GetEncodings())
{
Encoding e = ei.GetEncoding();
Console.Write("{0,-15} - {1}{2}", ei.CodePage, e.EncodingName, System.Environment.NewLine);
Console.WriteLine(e.GetString(data).Substring(0, 200));
Console.Write(System.Environment.NewLine + "---------------------" + System.Environment.NewLine);
}
Fiddle: https://dotnetfiddle.net/LcV5s8

Bit Array to String and back to Bit Array

Possible Duplicate Converting byte array to string and back again in C#
I am using Huffman Coding for compression and decompression of some text from here
The code in there builds a huffman tree to use it for encoding and decoding. Everything works fine when I use the code directly.
For my situation, i need to get the compressed content, store it and decompress it when ever need.
The output from the encoder and the input to the decoder are BitArray.
When I tried convert this BitArray to String and back to BitArray and decode it using the following code, I get a weird answer.
Tree huffmanTree = new Tree();
huffmanTree.Build(input);
string input = Console.ReadLine();
BitArray encoded = huffmanTree.Encode(input);
// Print the bits
Console.Write("Encoded Bits: ");
foreach (bool bit in encoded)
{
Console.Write((bit ? 1 : 0) + "");
}
Console.WriteLine();
// Convert the bit array to bytes
Byte[] e = new Byte[(encoded.Length / 8 + (encoded.Length % 8 == 0 ? 0 : 1))];
encoded.CopyTo(e, 0);
// Convert the bytes to string
string output = Encoding.UTF8.GetString(e);
// Convert string back to bytes
e = new Byte[d.Length];
e = Encoding.UTF8.GetBytes(d);
// Convert bytes back to bit array
BitArray todecode = new BitArray(e);
string decoded = huffmanTree.Decode(todecode);
Console.WriteLine("Decoded: " + decoded);
Console.ReadLine();
The Output of Original code from the tutorial is:
The Output of My Code is:
Where am I wrong friends? Help me, Thanks in advance.
You cannot stuff arbitrary bytes into a string. That concept is just undefined. Conversions happen using Encoding.
string output = Encoding.UTF8.GetString(e);
e is just binary garbage at this point, it is not a UTF8 string. So calling UTF8 methods on it does not make sense.
Solution: Don't convert and back-convert to/from string. This does not round-trip. Why are you doing that in the first place? If you need a string use a round-trippable format like base-64 or base-85.
I'm pretty sure Encoding doesn't roundtrip - that is you can't encode an arbitrary sequence of bytes to a string, and then use the same Encoding to get bytes back and always expect them to be the same.
If you want to be able to roundtrip from your raw bytes to string and back to the same raw bytes, you'd need to use base64 encoding e.g.
http://blogs.microsoft.co.il/blogs/mneiter/archive/2009/03/22/how-to-encoding-and-decoding-base64-strings-in-c.aspx

How to prevent conversion of Windows-1252 argument into a Unicode string?

I've written my first COM classes. My unit tests work fine, but my first use of the COM objects has hit a snag.
The COM classes provide methods which accept a string, manipulate it and return a string. The consumer of the COM objects is a dBASE PLUS program.
When the input string contains common keyboard characters (ASCII 127 or lower), the COM methods work fine. However, if the string contains characters beyond the ASCII range, some of them get remapped from Windows-1252 to C#'s Unicode. This table shows the mapping that takes place: http://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/CP1252.TXT
For example, if the dBASE program calls the COM object with:
oMyComObject.MyMethod("It will cost€123") where the € is hex 80,
the C# method receives it as Unicode:
public string MyMethod(string source)
{
// source is Unicode and now the Euro symbol is hex 20AC
...
}
I would like to avoid this remapping because I want the original hex content of the string.
I've tried adding the following to MyMethod to convert the string back to Windows-1252, but the Euro symbol gets lost because it becomes a question mark:
byte[] UnicodeBytes = Encoding.Unicode.GetBytes(source.ToString());
byte[] Win1252Bytes = Encoding.Convert(Encoding.Unicode, Encoding.GetEncoding(1252), UnicodeBytes);
string Win1252 = Encoding.GetEncoding(1252).GetString(Win1252Bytes);
Is there a way to prevent this conversion of the "source" parameter to Unicode? Or, is there a way to convert it 100% from Unicode back to Windows-1252?
Yes, I'm answering my own question. The answer by "Jigsore" put me on the right track, but I want to explain more clearly in case someone else makes the same mistake I made.
I eventually figured out that I had misdiagnosed the problem. dBASE was passing the string fine and C# was receiving it fine. It was how I checked the contents of the string that was in error.
This turnkey builds on Jigsore's answer:
void Main()
{
string unicodeText = "\u20AC\u0160\u0152\u0161";
byte[] unicodeBytes = Encoding.Unicode.GetBytes(unicodeText);
byte[] win1252bytes = Encoding.Convert(Encoding.Unicode, Encoding.GetEncoding(1252), unicodeBytes);
for (int i = 0; i < win1252bytes.Length; i++)
Console.Write("0x{0:X2} ", win1252bytes[i]); // output: 0x80 0x8A 0x8C 0x9A
// win1252String represents the string passed from dBASE to C#
string win1252String = Encoding.GetEncoding(1252).GetString(win1252bytes);
Console.WriteLine("\r\nWin1252 string is " + win1252String); // output: Win1252 string is €ŠŒš
Console.WriteLine("looking at the code of the first character the wrong way: " + (int)win1252String[0]);
// output: looking at the code of the first character the wrong way: 8364
byte[] bytes = Encoding.GetEncoding(1252).GetBytes(win1252String[0].ToString());
Console.WriteLine("looking at the code of the first character the right way: " + bytes[0]);
// output: looking at the code of the first character the right way: 128
// Warning: If your input contains character codes which are large in value than what a byte
// can hold (ex: multi-byte Chinese characters), then you will need to look at more than just bytes[0].
}
The reason the first method was wrong is that casting (int)win1252String[0] (or the converse of casting an integer j to a character with (char)j) involves an implicit conversion with the Unicode character set C# uses.
I consider this resolved and would like to thank each person who took the time to comment or answer for their time and trouble. It is appreciated!
Actually you're doing the Unicode to Win-1252 conversion correctly, but you're performing an extra step. The original Win1252 codes are in the Win1252Bytes array!
Check the following code:
string unicodeText = "\u20AC\u0160\u0152\u0161";
byte[] unicodeBytes = Encoding.Unicode.GetBytes(unicodeText);
byte[] win1252bytes = Encoding.Convert(Encoding.Unicode, Encoding.GetEncoding(1252), unicodeBytes);
for (i = 0; i < win1252bytes.Length; i++)
Console.Write("0x{0:X2} ", win1252bytes[i]);
The output shows the Win-1252 codes for the unicodeText string, you can check this by looking at the CP1252.TXT table.

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