Converting String to List of Bytes - vb.net

This has to be incredibly simple, but I must not be looking in the right place.
I'm receiving this string via a FTDI usb connection:
'UUU'
I would like to receive this as a byte array of
[85,85,85]
In Python, this I would convert a string to a byte array like this:
[ord(c) for c in 'UUU']
I've looked around, but haven't figured this out. How do I do this in Visual Basic?

Use the Encoding class with the correct encoding.
C#:
// Assuming string is UTF8
Encoding utf8 = Encoding.UTF8Encoding();
byte[] bytes = utf8.GetBytes("UUU");
VB.NET:
Dim utf8 As Encoding = Encoding.UTF8Encoding()
Dim bytes As Byte() = utf8.GetBytes("UUU")

depends on what kind of encoding you want to use but for UTF8 this works, you could chane it to UTF16 if needed.
Dim strText As String = "UUU"
Dim encText As New System.Text.UTF8Encoding()
Dim btText() As Byte
btText = encText.GetBytes(strText)

Related

encrypt a string using SHA512

Here 's my code and I have no idea why it produces a weird code in the console
(output is "b5?2???p?????'5???.?H???Kun???a??\??d??+\??%??A)?_???j?" without the quotes)
Private Sub TestSHA512()
Dim key As String = "635357773463315343"
Dim pass As String = "somepasswd"
Dim enc As System.Text.Encoding = New System.Text.ASCIIEncoding
Dim keyBytes() As Byte = enc.GetBytes(key)
Dim passBytes() As Byte = enc.GetBytes(pass)
Dim SHA As New HMACSHA512(keyBytes)
Dim resultBytes() As Byte = SHA.ComputeHash(passBytes)
Console.WriteLine(enc.GetString(resultBytes))
Console.WriteLine(enc.GetString(SHA.Hash)) 'same...
End Sub
First, SHA512 is a hash algorithm, not an encryption scheme, so if you're trying to encrypt then SHA512 isn't the way to do it. You'd need to look at an encryption class, such as AesManaged.
ComputeHash gives you the computed hash as a byte array. You're using ASCIIEncoding.GetString to convert that into a string, but not every byte is a printable ASCII character. That's why you're seeing the ??? characters in your console output.
If you're asking how to display the hash output as a printable string, use Convert.ToBase64String, which will convert the byte array into a string using base64 encoding. If you were expecting it in hexadecimal, you can loop through the byte array and print the Hex() value of each byte.

Read Data From The Byte Array Returned From Web Service

I have a web service,which return data in byte array.Now i want to read that data in my console project.How can i do that,i already add the desire references to access that web service.I am using vb.net VS2012.Thanks.My web service method is as follow.
Public Function GetFile() As Byte()
Dim response As Byte()
Dim filePath As String = "D:\file.txt"
response = File.ReadAllBytes(filePath)
Return response
End Function
Something like,
Dim result As String
Using (Dim data As New MemoryStream(response))
Using (Dim reader As New StreamReader(data))
result = reader.ReadToEnd()
End Using
End Using
if you knew the encoding, lets say it was UTF-8 you could do,
Dim result = System.Text.UTF8Encoding.GetString(response)
Following on from your comments, I think you are asserting this.
Dim response As Byte() 'Is the bytes of a Base64 encoded string.
So, we know all the bytes will be valid ASCII (because its Base64,) so the string encoding is interchangable.
Dim base64Encoded As String = System.Text.UTF8Encoding.GetString(response)
Now, base64Encoded is the string Base64 representation of some binary.
Dim decodedBinary As Byte() = Convert.FromBase64String(base64Encoded)
So, we've changed the encoded base64 into the binary it represents. Now, because I can see that in your example, you are reading a file called "D:/file.txt" I'm going to make the assumption that the contents of the file is a character encoded string, but I don't know the encoding of the string. The StreamReader class has some logic in the constructor that can make an educated guess at character encoding.
Dim result As String
Using (Dim data As New MemoryStream(decodedBinary))
Using (Dim reader As New StreamReader(data))
result = reader.ReadToEnd()
End Using
End Using
Hopefully, now result contains the context of the text file.

How can I read Greek characters from my database in my web app?

I've got Greek text stored in my access database. For some reason it doesn't appear in Greek- it uses other symbols instead.
e.g. Ãëþóóá instead of Γλώσσα
I can convert it in my windows app like this:
Dim encoder As Encoding = Encoding.GetEncoding(1253)
Dim valueInBytes As Byte() = encoder.System.IO.File.ReadAllBytes(lanuageFilePath)
languageValue = encoder.GetString(valueInBytes)
However, I now need to use the values in my web app. But the ReadAllBytes method is not available to me. I've tried using GetBytes instead, but this doesn't seem to produce the same results.
Dim encoder As Encoding = Encoding.GetEncoding(1253)
Dim valueInBytes As Byte() = encoder.GetBytes(languageValue)
languageValue = encoder.GetString(valueInBytes)
What am I doing wrong?
The first one seems to have nothing to do with text in a variable, your reading from a file.
Dim encoder As Encoding = Encoding.GetEncoding(1253)
Dim valueInBytes As Byte() = System.IO.File.ReadAllBytes(languageValue)
languageValue = encoder.GetString(valueInBytes)
ReadAllBytes should be supported in most frameworks so there should not be a problem with this on the server.
The other code seems to be doing soething compleatly different. You are converting the string to bytes and back again in the same encoding, to get this to work you need to find out which encoding access thought it was and encode with that. However it may still not have survived the roundtrip as access may be doing some normalistion of the unicode.
Dim encoder As Encoding = Encoding.GetEncoding(1253)
Dim accessencoder As Encoding = Encoding.GetEncoding({{accesses encoding numer here}})
Dim valueInBytes As Byte() = accessencoder.GetBytes(languageValue)
languageValue = encoder.GetString(valueInBytes)

Converting UTF-8 to windows-1255 encoding in VB.NET

I am trying to convert a string encoded in UTF-8 to windows-1255 in VB.NET with no luck. Admittedly, I don't know VB but have tried using an example at MSDN and modifying it to my needs:
Public Function Utf82Hebrew(ByVal Str As String) As String
Dim ascii As Encoding = Encoding.GetEncoding("windows-1255")
Dim unicode As Encoding = Encoding.Unicode
' Convert the string into a byte array.
Dim unicodeBytes As Byte() = unicode.GetBytes(Str)
' Perform the conversion from one encoding to the other.
Dim asciiBytes As Byte() = Encoding.Convert(unicode, ascii, unicodeBytes)
' Convert the new byte array into a char array and then into a string.
Dim asciiChars(ascii.GetCharCount(asciiBytes, 0, asciiBytes.Length)-1) As Char
ascii.GetChars(asciiBytes, 0, asciiBytes.Length, asciiChars, 0)
Dim asciiString As New String(asciiChars)
Utf82Hebrew = asciiString
End Function
This function doesn't actually do anything—the string remains in UTF-8. However, if I change this line:
Dim ascii As Encoding = Encoding.GetEncoding("windows-1255")
To this:
Dim ascii As Encoding = Encoding.ASCII
Then the function returns question marks in the place of the string.
Does anyone know how to properly convert a UTF-8 string to a specific encoding (in this case, windows-1255), and/or what I'm doing wrong in the above code?
Thanks in advance.
I modified your code.
It is very straightforward to convert text from one encoding into another.
This is how you should do it in VB.Net.
Microsof Windows file encoding is 1252, not 1255.
Public Function Utf82Hebrew(ByVal Str As String) As String
Dim ascii As System.Text.Encoding = System.Text.Encoding.GetEncoding("1252")
Dim unicode As System.Text.Encoding = System.Text.Encoding.Unicode
' Convert the string into a byte array.
Dim unicodeBytes As Byte() = unicode.GetBytes(Str)
' Perform the conversion from one encoding to the other.
Dim asciiBytes As Byte() = System.Text.Encoding.Convert(unicode, ascii, unicodeBytes)
' Convert the new byte array into a char array and then into a string.
Dim asciiString As String = ascii.GetString(asciiBytes)
Utf82Hebrew = asciiString
End Function

Converting non-Unicode to Unicode

I'm trying to convert a non-Unicode string like this, '¹ûº¤¡¾­¢º¤ìñ©2' to Unicode like this, 'ໃຊ້ໃນຄົວເຮືອນ' which is in Lao. I tried with the code below and its return value is like this, '??????'. Any idea how can I convert the string?
Public Shared Function ConvertAsciiToUnicode(asciiString As String) As String
' Create two different encodings.
Dim encAscii As Encoding = Encoding.ASCII
Dim encUnicode As Encoding = Encoding.Unicode
' Convert the string into a byte[].
Dim asciiBytes As Byte() = encAscii.GetBytes(asciiString)
' Perform the conversion from one encoding to the other.
Dim unicodeBytes As Byte() = Encoding.Convert(encAscii, encUnicode, asciiBytes)
' Convert the new byte[] into a char[] and then into a string.
' This is a slightly different approach to converting to illustrate
' the use of GetCharCount/GetChars.
Dim unicodeChars As Char() = New Char(encUnicode.GetCharCount(unicodeBytes, 0, unicodeBytes.Length) - 1) {}
encUnicode.GetChars(unicodeBytes, 0, unicodeBytes.Length, unicodeChars, 0)
Dim unicodeString As New String(unicodeChars)
' Return the new unicode string
Return unicodeString
End Function
Your 8-bit encoded Lao text is not in ASCII, but in some codepage like IBM CP1133 or Microsoft LC0454, or most likely, the Thai codepage 874. You have to find out which one it is.
It matters how you have obtained (read, received, computed) the input string. By the time you make it a string it is already in Unicode and is easy to output in UTF-8, for example, like this:
Dim writer As New StreamWriter("myfile.txt", True, System.Text.Encoding.UTF8)
writer.Write(mystring)
writer.Close()
Here is the whole in-memory conversion:
Dim utf8_input as Byte()
...
Dim converted as Byte() = Encoding.Convert(Encoding.GetEncoding(874), Encoding.UTF8, utf8_input)
The number 874 is the number that says in which codepage your input is. Whether a particular operating system installation supports this codepage, is another question, but your own system will nearly certainly support it if you just used it to compose your Stack Overflow question.