Order of bytes after BitArray to byte[] convertation - c#

I'm, trying to figure out bytes order after convertation from BitArray to byte[].
Firstly, here is the BitArray content:
BitArray encoded = huffmanTree.Encode(input);
foreach (bool bit in encoded)
{
Console.Write((bit ? 1 : 0));
}
Console.WriteLine();
Output:
Encoded: 000001010110101011111111
Okay, so if we convert these binary to Hex manually we will get: 05 6A FF
However, when I am using convertation in C#, here is what I get:
BitArray encoded = huffmanTree.Encode(input);
byte[] bytes = new byte[encoded.Length / 8 + (encoded.Length % 8 == 0 ? 0 : 1)];
encoded.CopyTo(bytes, 0);
string StringByte = BitConverter.ToString(bytes);
Console.WriteLine(StringByte); // just to check the Hex
Output:
A0-56-FF
Nevertheless, as I have mentioned, it should be 05 6A FF. Please help me to understand why is that so.

Related

find the size of a JSON string before submitting it to a Azure Queue [duplicate]

I'm wondering if I can know how long in bytes for a string in C#, anyone know?
You can use encoding like ASCII to get a character per byte by using the System.Text.Encoding class.
or try this
System.Text.ASCIIEncoding.Unicode.GetByteCount(string);
System.Text.ASCIIEncoding.ASCII.GetByteCount(string);
From MSDN:
A String object is a sequential collection of System.Char objects that represent a string.
So you can use this:
var howManyBytes = yourString.Length * sizeof(Char);
System.Text.ASCIIEncoding.Unicode.GetByteCount(yourString);
Or
System.Text.ASCIIEncoding.ASCII.GetByteCount(yourString);
How many bytes a string will take depends on the encoding you choose (or is automatically chosen in the background without your knowledge). This sample code shows the difference:
void Main()
{
string text = "a🡪";
Console.WriteLine("{0,15} length: {1}", "String", text.Length);
PrintInfo(text, Encoding.ASCII); // Note that '🡪' cannot be encoded in ASCII, information loss will occur
PrintInfo(text, Encoding.UTF8); // This should always be your choice nowadays
PrintInfo(text, Encoding.Unicode);
PrintInfo(text, Encoding.UTF32);
}
void PrintInfo(string input, Encoding encoding)
{
byte[] bytes = encoding.GetBytes(input);
var info = new StringBuilder();
info.AppendFormat("{0,16} bytes: {1} (", encoding.EncodingName, bytes.Length);
info.AppendJoin(' ', bytes);
info.Append(')');
string decodedString = encoding.GetString(bytes);
info.AppendFormat(", decoded string: \"{0}\"", decodedString);
Console.WriteLine(info.ToString());
}
Output:
String length: 3
US-ASCII bytes: 3 (97 63 63), decoded string: "a??"
Unicode (UTF-8) bytes: 5 (97 240 159 161 170), decoded string: "a🡪"
Unicode bytes: 6 (97 0 62 216 106 220), decoded string: "a🡪"
Unicode (UTF-32) bytes: 8 (97 0 0 0 106 248 1 0), decoded string: "a🡪"

RSA Encrypt Handle invalid issue

I am trying to encrypt a text and the decrypt it using public private key pair. I need the keys to handled as string. So I convert these key from string to RSAParameters. But when i try to encrypt the text, it throws me an error as "The handle is not valid".
static RSAParameters _publicKey = new RSAParameters();
static RSAParameters _privateKey = new RSAParameters();
static string _strPublicKey = "-----BEGIN PUBLIC KEY-----\r\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsG5sBbnH7gXkrExzNOeK\r\nEjoRDHUH5uU+crH52Z1uXCEx8LiFow8RwrvZGqjYXgBwxzqOQwHJt3utoNVY0niP\r\nHjfPXwKTk79PkeET/mtRar1gEcCOr0/hgHxT3YGlQLw2ugVIulMzlUBRY4rceNv3\r\nEiSZ+4cnO04hJ6UiftrCfwTe6q9Hadp6B6SX+N9hgcHhRX4iR/VYUf/6cvN+NAgb\r\ntuF0Dk61C6ulh2Gvdj2TBCLaq1LPF5H+ghrRxjK/Zn6MG9BW2ju9g8zYKuufaaaM\r\ndbTmN+Z4f27nEOxFq5wWqeaWl53yrMia6xnOi7vtU8zcwBL7jSLgwrkyO8LabCdz\r\neQIDAQAB\r\n-----END PUBLIC KEY-----";
static string _strPrivateKey = "-----BEGIN RSA PRIVATE KEY-----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\r\nDsUL5Ia5W7/Cm7d0/nqchUCkRslIsH+bfGj0NZ7qcE5H1D8Ee0A=\r\n-----END RSA PRIVATE KEY-----";
static void Main(string[] args)
{
var message = "Hello World!";
var data = Encrypt(message);
var res = Decrypt(data);
}
private static RSAParameters GetRSAParameters(string pPublicKey)
{
byte[] lDer;
//Set RSAKeyInfo to the public key values.
int lBeginStart = "-----BEGIN PUBLIC KEY-----".Length;
int lEndLenght = "-----END PUBLIC KEY-----".Length;
string KeyString = pPublicKey.Substring(lBeginStart, (pPublicKey.Length - lBeginStart - lEndLenght));
lDer = Convert.FromBase64String(KeyString);
//Create a new instance of the RSAParameters structure.
RSAParameters lRSAKeyInfo = new RSAParameters();
lRSAKeyInfo.Modulus = GetModulus(lDer);
lRSAKeyInfo.Exponent = GetExponent(lDer);
return lRSAKeyInfo;
}
private static byte[] GetModulus(byte[] pDer)
{
//Size header is 29 bits
//The key size modulus is 128 bits, but in hexa string the size is 2 digits => 256
string lModulus = BitConverter.ToString(pDer).Replace("-", "").Substring(58, 256);
return StringHexToByteArray(lModulus);
}
private static byte[] GetExponent(byte[] pDer)
{
int lExponentLenght = pDer[pDer.Length - 3];
string lExponent = BitConverter.ToString(pDer).Replace("-", "").Substring((pDer.Length * 2) - lExponentLenght * 2, lExponentLenght * 2);
return StringHexToByteArray(lExponent);
}
public static byte[] StringHexToByteArray(string hex)
{
return Enumerable.Range(0, hex.Length)
.Where(x => x % 2 == 0)
.Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
.ToArray();
}
public static string Encrypt(string mess)
{
string response = "";
var input = Encoding.UTF8.GetBytes(mess);
using (var rsa = new RSACryptoServiceProvider(1024))
{
rsa.PersistKeyInCsp = false;
rsa.ImportParameters(GetRSAParameters(_strPublicKey));
var decrypt = rsa.Encrypt(input, true);
response = Convert.ToBase64String(decrypt);
}
return response;
}
public static string Decrypt(string mess)
{
string response = "";
var input = Convert.FromBase64String(mess);
using (var rsa = new RSACryptoServiceProvider(2048))
{
rsa.PersistKeyInCsp = false;
rsa.ImportParameters(GetRSAParameters(_strPublicKey));
var decrypt = rsa.Decrypt(input, false);
response = Encoding.UTF8.GetString(decrypt);
}
return response;
}
Above is the code that I am using to encrypt and decrypt. After the conversion, I convert them to string and pass it to the decrypt function. Please advice
Your attempt to read the DER is definitely lacking. Possibly because you have a 2048-bit key and your "parser" at best only works for a 1024-bit key (though I'm having trouble deciding what key it could legitimately read).
Your public key hex is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The DER breakdown (because I can't help myself) is
30 82 01 22
30 0D
06 09 2A 86 48 86 F7 0D 01 01 01
05 00
03
82 01 0F
00
30 82 01 0A
02 82 01 01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02 03
010001
Which is the ASN.1 equivalent of
SEQUENCE
SEQUENCE
OBJECT IDENTIFIER id-rsaEncryption
NULL
BIT STRING (0 bits unused) (wrapping)
SEQUENCE
INTEGER (positive) 0xB06E...7379
INTEGER 0x010001
Your modulus extractor skips 29 bytes and reads the next 128. (Why it does byte[] => hex => substring => byte[] instead of doing new byte[size] and Buffer.BlockCopy is beyond me). The problem is, your key is a 2048-bit key (the modulus length is 0x0101, and once we remove the sign-padding byte it's 0x0100 bytes long, with the high bit set, so 256*8 = 2048 bit modulus). So you need to have read 256 bytes. And, worse, because the payload is bigger than expected, it doesn't start at the offset you think it does. So where you should end up with B0 6E 6C ... 27 73 79 (after skipping the padding byte) you ended up with 82 01 01 00 *B0 6E 6C ... A5 22 7E (the asterisk marking the desired start of your payload). So, that's bad, and you are definitely not encrypting what you think you are. (The A5 22 7E sequence occurs on the line starting with 36BA, ending with 3 bytes left to go on that line)
What's worse is the GetExponent method. It seems to try to combine actual DER reading with presupposing what the value is. It should conclude 01 00 01, but it reads the first 01 of the payload as a length, then uses that length to count from the end. So the exponent value ends up being just 01. The RSA algorithm doesn't work with e=1, and what's happening is probably that a post-encryption self-test decided that the results were garbage, and the Win32 crypto library concluded that the problem is that the caller gave it something that wasn't a valid key handle, as opposed to a valid handle to an invalid key. In addition to not understanding the byte[] => hex => substring => byte[] pattern here I don't understand why this code decided that pDer[-3] (to use syntax from another language) was the length value. DER can only be read "left to right", and if it knew "the exponent is always 0x010001" then a) that'd be length-encoded at pDer[-4] b) just reading the last three bytes would be forgivable and c) given how many assumptions this code makes it would've made more sense to just blindly assume 0x010001.
So, you need to a) replace your parser with either a correct parser or at least a specialized one which functions at your desired keysize and b) never use that private key for anything important, since you just posted it to the Internet (and the private key variable wasn't even used in this problem).

C# Ascii to bytes, parsing not conversion

I have a windows form where you can input text in one textbox, and it outputs the conversion in the other textbox. I have various conversions.
say I input "hello world"
my ascii to bytes function gives me back: 10410110810811132119111114108100
all is good. now I need to use my bytes to ascii function to convert it back.
the problem is that
byte[] b;
b = ASCIIEncoding.ASCII.GetBytes(plaintext); //it is a string from the textbox
OK, MOSTLY SOLVED, BUT, the problem still remains, input "1101000 1100101" as a string, parse as bytes/ byte array, and then get a string out of it. (I know the last part)
UPDATE
From binary input string to ASCII string
using System;
using System.Linq;
public class Program
{
public static void Main()
{
string input = "1101000 1100101 1101100 1101100 1101111 100000 1110111 1101111 1110010 1101100 1100100";
string[] binary = input.Split(' ');
Console.WriteLine(String.Join("", binary.Select(b => Convert.ToChar(Convert.ToByte(b, 2))).ToArray()));
}
}
Results:
hello world
Demo
OLD ANSWER
So now it sounds like you want to convert your string to binary and then from binary back to a string. From my OLD ANSWER, you can use the Select() (LINQ) statement to convert your string to a binary string array.
Once you have a binary string array, to convert it back you have to convert each element to a byte from base 2, then convert the byte to a char resulting in a char[], from which can be converting back to a string. No padding is necessary.
using System;
using System.Linq;
using System.Text;
public class Program
{
public static void Main()
{
string input = "hello world";
byte[] inputBytes = ASCIIEncoding.ASCII.GetBytes(input);
// Decimal display
Console.WriteLine(String.Join(" ", inputBytes));
// Hex display
Console.WriteLine(String.Join(" ", inputBytes.Select(ib => ib.ToString("X2"))));
// Binary display
string[] binary = inputBytes.Select(ib => Convert.ToString(ib, 2)).ToArray();
Console.WriteLine(String.Join(" ", binary));
// Converting bytes back to string
Console.WriteLine(ASCIIEncoding.ASCII.GetString(inputBytes, 0, inputBytes.Length));
// Binary to ASCII (This is what you're looking for)
Console.WriteLine(String.Join("", binary.Select(b => Convert.ToChar(Convert.ToByte(b, 2)))));
}
}
Results:
104 101 108 108 111 32 119 111 114 108 100
68 65 6C 6C 6F 20 77 6F 72 6C 64
1101000 1100101 1101100 1101100 1101111 100000 1110111 1101111 1110010 1101100 1100100
hello world
hello world
Demo
The inverse to ASCIIEncoding.ASCII.GetBytes(string) is ASCIIEncoding.ASCII.GetString(bytes[]):
string plaintext = "hello world";
byte[] b = ASCIIEncoding.ASCII.GetBytes(plaintext);
Console.WriteLine(b); // new bytes[] { 104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100 }
string s = ASCIIEncoding.ASCII.GetString(b);
Console.WriteLine(s); // "hello world"
how the heck does ASCIIEncoding.ASCII.GetBytes("hello world") give me back 10410110810811132119111114108100?! that's not binary!
It does not give you that number. It gives you a byte array; an array of bytes. And a byte is a number between 0 and 255 (which can be stored in one byte, hence them name). What did you expect? A string containing only 1 and 0 characters? That’s not binary either; that’s a string.
You can use Convert.ToString to get a binary string from a single byte:
Console.WriteLine(Convert.ToString(104, 2)); // "1101000"
Note that you need to left-pad those strings to make them use 8 characters.

How to convert from Hex to Unicode?

My application receives Hex values from client and converts back to character which is usually chinese character. But I can't implement this properly. As per my current programme it can convert "e5a682e4bd95313233" to "如何123" but I am actually receiving "59824F55003100320033" from the client side for the same Chinese character "如何123" and my programme unable to convert back into string. Please help me on this.
Here is my current code:
byte[] uniMsg = null;
string msg = "59824F55003100320033";
uniMsg = StringToByteArray(msg.ToUpper());
msg = System.Text.Encoding.UTF8.GetString(uniMsg);
public static byte[] StringToByteArray(String hex)
{
hex = hex.Replace("-", "");
byte[] raw = new byte[hex.Length / 2];
for (int i = 0; i < raw.Length; i++)
{
raw[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
}
return raw;
}
Appreciate any help on this. Thanks.
Solution:
updated
msg = System.Text.Encoding.UTF8.GetString(uniMsg);
to
msg = System.Text.Encoding.BigEndianUnicode.GetString(uniMsg)
Thanks to #CodesInChaos for suggesting the encoding type.
It doesn't seem to be encoded in UTF8. Note the 00 31 00 32 00 33 part. In UTF8, it'd be just 31 32 33. I think the hexstring is in UTF16 BE, because it's exactly 2 bytes per character and they are 00-padded. Decode your byte array as UTF16, you will get a string. Then you can use it as string, or reconvert it to any other encoding you need.

How to know the size of the string in bytes?

I'm wondering if I can know how long in bytes for a string in C#, anyone know?
You can use encoding like ASCII to get a character per byte by using the System.Text.Encoding class.
or try this
System.Text.ASCIIEncoding.Unicode.GetByteCount(string);
System.Text.ASCIIEncoding.ASCII.GetByteCount(string);
From MSDN:
A String object is a sequential collection of System.Char objects that represent a string.
So you can use this:
var howManyBytes = yourString.Length * sizeof(Char);
System.Text.ASCIIEncoding.Unicode.GetByteCount(yourString);
Or
System.Text.ASCIIEncoding.ASCII.GetByteCount(yourString);
How many bytes a string will take depends on the encoding you choose (or is automatically chosen in the background without your knowledge). This sample code shows the difference:
void Main()
{
string text = "a🡪";
Console.WriteLine("{0,15} length: {1}", "String", text.Length);
PrintInfo(text, Encoding.ASCII); // Note that '🡪' cannot be encoded in ASCII, information loss will occur
PrintInfo(text, Encoding.UTF8); // This should always be your choice nowadays
PrintInfo(text, Encoding.Unicode);
PrintInfo(text, Encoding.UTF32);
}
void PrintInfo(string input, Encoding encoding)
{
byte[] bytes = encoding.GetBytes(input);
var info = new StringBuilder();
info.AppendFormat("{0,16} bytes: {1} (", encoding.EncodingName, bytes.Length);
info.AppendJoin(' ', bytes);
info.Append(')');
string decodedString = encoding.GetString(bytes);
info.AppendFormat(", decoded string: \"{0}\"", decodedString);
Console.WriteLine(info.ToString());
}
Output:
String length: 3
US-ASCII bytes: 3 (97 63 63), decoded string: "a??"
Unicode (UTF-8) bytes: 5 (97 240 159 161 170), decoded string: "a🡪"
Unicode bytes: 6 (97 0 62 216 106 220), decoded string: "a🡪"
Unicode (UTF-32) bytes: 8 (97 0 0 0 106 248 1 0), decoded string: "a🡪"

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