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I have used VB6 one module for encryption / decryption and compare the encrypted string
with another string which always say Not Matched.

Below is the code

What I have tried:

Dim a As String
a = modEncDec.AesEncryptString("a", "PASS") ' Encrypted Value of a is tA==
If a = "tA==" Then
MsgBox "The Value of a is " & a, vbOKOnly, "Matched"
MsgBox "The Value of a is " & a, vbOKOnly, "Not Matched"
End If

Else Part is executed even though the Strings were same.
Updated 5-Aug-22 7:54am
Richard MacCutchan 5-Aug-22 5:47am    
It is quite possible that the encrypted text contains some non-displayable characters. Try writing it to a file and see how many actual bytes you get. Have you actually tried to decrypt it to check that the original text is returned?

Having said that, you do realise that VB6 has been dead for more than 20 years.

The chances are that the problem lies in the use of strings: AES encryption does not generate a string but a stream of byte values which is not the same thing.
VB6 internally used Unicode for string storage, which is a multibyte character, so it's very, very possible that the conversion to a string is what's causing the problem - the characters you see are not what the "string" returned by the encryption process produces.

Try using an array of bytes instead and see exactly what you get.
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Member 11291660 5-Aug-22 13:47pm    
Thank you Mr. OriginalGriff.
After Converting it as byte array, I encountered two more characters were added at the end. Chr(10) and Chr(13) [vbCrLf].

Removing these two character did the job. Thank you
OriginalGriff 5-Aug-22 13:49pm    
You're welcome!
It looks like you are encrypting the string "a", decrypting it and then comparing it to the string "tA==".

Try comparing to the string "a" instead and see if that works.
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Richard MacCutchan 5-Aug-22 12:00pm    
No s/he is comparing the encrypted string; there is no decryption.
Member 11291660 5-Aug-22 13:52pm    
Mr.Fueled By Decaff, You are Right. Both are different in length.
My 5 Stars
Dim a As String
Dim b As String
a = modEncDec.AesEncryptString("a", "PASS")
b = "tA=="
a = Replace(a, vbCrLf, "")
If a = b Then
MsgBox "The Value of a is " & a & vbCrLf _
        & "The Length of a is " & Len(a) & vbCrLf _
        & "The Value of b is " & b & vbCrLf _
        & "The Length of b is " & Len(b) & vbCrLf, _
         vbOKOnly, "Matched"
MsgBox "The Value of a is " & a & vbCrLf & "The Length of a is " & Len(a) & vbCrLf _
        & "The Value of b is " & b & vbCrLf _
        & "The Length of b is " & Len(b) & vbCrLf, _
        vbOKOnly, "Not Matched"
End If
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