How do I compute HMACSHA256 in an Open Office VBasic Script? - vba

Admittely I understand that I'm using a VBA script, but I cannot find information to confirm that this specific call in question is not specifically supported for OpenOffice. I currently have a ComputeHMACSha256 function that seems to be referenced several places online for computing Sha 256 hashes with a key string (albeit with Excel, NOT Open Office). However, when I attempt to run ComputeHash or the overload ComputeHash_2, I get this error:
I've got NET.2 and 3 installed and configured from what I can see in the Turn Windows feature screen:
And here is the code I'm using, taken from here:
Function CommandButton1_Click()
MsgBox("Hello World")
call UsageExample()
Call makeJWT()
End Function
Function makeJWT()
rsString = "{'alg': 'RS256','typ': 'JWT'}"
res = ComputeHMACSHA256("test", rsString)
MsgBox(res)
End Function
Function ComputeHMACSHA256(rsaKey As String, body As String) As String
Dim encoder As Object, crypto As Object
Dim hash() As Byte, hmacsha As String, i As Long
' compute HMACSHA256
Set encoder = CreateObject("System.Text.UTF8Encoding")
Set crypto = CreateObject("System.Security.Cryptography.HMACSHA256")
crypto.Key = encoder.GetBytes_4(rsaKey)
hash = crypto.ComputeHash_2(encoder.GetBytes_4(body))
' convert to an hexa string
hmacsha = String(64, "0")
For i = 0 To 31
Mid$(hmacsha, i + i + (hash(i) > 15) + 2) = Hex(hash(i))
Next
ComputeHMACSHA256 = LCase(hmacsha)
End Function

Related

Formula Written in Module Producing #VALUE

With assistance from outside sources I have this code that takes latitude and longitude and extracts zipcodes. Here is the code:
Public Function ReverseGeoCode(myInput1 As String, myInput2 As String) As String
'You will need to reference Microsoft XML, v6.0 object library
Dim XMLDoc As New DOMDocument60
Dim XMLNODE As IXMLDOMNode
Dim I As Long
Dim lat, lng, myAddress, myZipcode, reportZipcode As String
Dim splitAddress, splitZipcode As Variant
lat = myInput1
lng = myInput2
XMLDoc.Load "http://maps.googleapis.com/maps/api/geocode/xml?latlng=" & lat & "," & lng & " &sensor=false"
Do Until XMLDoc.readyState = 4
DoEvents
Loop
If Len(XMLDoc.Text) = 0 Then
Call MsgBox("No Data!")
Exit Function
End If
Set XMLNode = XMLDoc.SelectSingleNode("/GeocodeResponse/result/formatted_address")
For i= 0 To XMLNode.ChildNodes.Length - 1
myAddress = XMLNode.ChildNodes(i).Text
Next i
splitAddress = Split(myAddress, ",")
myZipcode = splitAddress(2)
myZipcode = Trim(myZipcode)
splitZipcode = Split(myZipcode, " ")
reportZipcode = splitZipcode(1)
reportZipcode = Trim(reportZipcode)
ReverseGeoCode = reportZipcode
End Function
So the code works, and I know it might not be the cleanest. But the issue is when I call it in the Excel sheet using "=ReverseGeoCode(Cell1, Cell2)". Sometimes it works fine, other times it produces the return "#VALUE!" and I am not entirely sure why. I attached an image below to show you an example of the error. Does anyone have an idea of why this error is producing?
General observations:
So to pick up on what I wrote in the comments, here is an outline.
You don't want to use an User Defined Function. This will keep on making repeated calls. You definitely risk hitting a call limit to the API without an API key, and possibly with; it is inefficient and it is not necessary. Instead, write a sub which you call once and which loops all the required cells in the sheet and issues the API calls and returns the zip codes. An API key is a method of authentication used with many API calls. You shouldn't share it by the way.
These repeated calls, possibly hitting a limit and the fact that UDFs are frequently calculated maybe the source of your woes.
With efficiency in mind, first remove duplicates from the sheet to avoid calls that are not required. Switch of Screen-Updating and anything else e.g. CalculationMode to manual whilst performing.
From what I have read you require an API key once you have hit a daily limit. Not sure what the API limit is for free version or without API key.
Outline code (XML request with some psuedo code):
Option Explicit
Public Sub ListZipCodes()
Dim lat As Double, longitude As Double
Const APIKEY As String = "yourAPIkey"
Application.ScreenUpdating = False '<==Speed up code when actually working with sheet
'Code to remove duplicates
'Code to loop sheet and call function on each input set of values
'Example call. These would be picked up from cells
lat = 40.714224
longitude = -73.961452
Debug.Print GetZipCode(lat, longitude, APIKEY)
Application.ScreenUpdating = True
End Sub
Public Function GetZipCode(ByVal lat As Double, ByVal longitude As Double, ByVal APIKEY As String) As String
Dim sResponse As String
With CreateObject("MSXML2.XMLHTTP")
Dim URL As String
URL = "https://maps.googleapis.com/maps/api/geocode/xml?latlng=" & lat & "," & longitude & "&key=" & APIKEY
.Open "GET", URL, False
.send
If .Status <> 200 Then
GetZipCode = "API call failed"
Exit Function
End If
Dim XMLDoc As New DOMDocument60, XMLNODE As IXMLDOMNode
XMLDoc.Load .responseBody
If Len(XMLDoc.Text) = 0 Then GetZipCode = "No data"
Set XMLNODE = XMLDoc.SelectSingleNode("/GeocodeResponse/result/formatted_address")
GetZipCode = Split(Trim$(Split(XMLNODE.Text, Chr$(44))(2)), Chr$(32))(1)
End With
End Function
Requesting JSON rather than XML response:
The reason calling as JSON was falling over was that the response needed to be decoded. Here is the function re-written to handle a JSON response.
This requires the download of JSONConverter, which you then import and add a reference to Microsoft Scripting Runtime via VBE > Tools > References.
The example below was run with
latitude: 42.9865913391113,
longitude: -100.137954711914
VBA:
Public Function GetZipCode(ByVal lat As Double, ByVal longitude As Double, ByVal APIKEY As String) As String
Dim sResponse As String, json As Object
With CreateObject("MSXML2.XMLHTTP")
Dim URL As String, formattedAddress As String
URL = "https://maps.googleapis.com/maps/api/geocode/json?latlng=" & lat & "," & longitude & "&key=" & APIKEY
.Open "GET", URL, False
.send
If .Status <> 200 Then
GetZipCode = "API call failed"
Exit Function
End If
Set json = JsonConverter.ParseJson(StrConv(.responseBody, vbUnicode))
formattedAddress = json("results").item(1)("formatted_address")
GetZipCode = Split(Trim$(Split(formattedAddress, Chr$(44))(2)), Chr$(32))(1)
End With
End Function
With a JSON request the initial object you get back is a dictionary, as denoted by the opening "{" in the decoded response:
i.e. Set json = JsonConverter.ParseJson(StrConv(.responseBody, vbUnicode)) returns a dictionary object
The data of interest, in the dictionary, has the key "results", as you may observe from the above.
This can be accessed with json("results"), which returns a collection of dictionaries. This being denoted by the following "[", for collection, and subsequently by the start of the first dictionary within the collection, indicated again by "{".
I can grab the first dictionary in the collection by index with:
json("results").item(1)
An inspection of the keys in this dictionary shows that one of the keys is what we are after i.e."formatted_address".
It's associated value is a primitive datatype; in this case a string. This means we can directly access it using the key (a further object is not returned).
formattedAddress = json("results").item(1)("formatted_address")
Now that we have the address string, we can parse it as we did before:
GetZipCode = Split(Trim$(Split(formattedAddress, Chr$(44))(2)), Chr$(32))(1)
End note:
You can use Postman, amongst other tools, to test API calls, and in this case inspect the JSON response. Indeed, to see what kind of response you are getting full stop.
Help:
It is very quick and easy to set up a project, generate an API key and get started. Maybe 10 minutes to read through and perform.
Instructions on setting up a project and getting an API key
Enabling the API
Understanding how to make API calls to the Geocoding API

vb.net AES decryption returns "data is incomplete block"

I'm aware of the other thread on this issue (AES decryption error " The input data is not a complete block." Error vb.net), but I'm either not implementing the solutions offered there correctly, or something about my particular variant of this issue isn't covered by those solutions. In any event I'm getting the incomplete block error from the following code
Private GD As System.Security.Cryptography.Aes = System.Security.Cryptography.Aes.Create
Private PDB As New System.Security.Cryptography.Rfc2898DeriveBytes(EK, New Byte() {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64, &H76, &H65, &H64, &H65, &H76})
Public Function Decrypt(ByVal val As String) As String
Dim ret As String = Nothing
Dim TTB As New System.Text.UTF8Encoding
Try
Dim input() As Byte = TTB.GetBytes(val)
Using ms As New System.IO.MemoryStream(input)
Using cs As New System.Security.Cryptography.CryptoStream(ms, GD.CreateDecryptor(PDB.GetBytes(32), PDB.GetBytes(16)), Security.Cryptography.CryptoStreamMode.Read)
Using sr As New System.IO.StreamReader(cs)
ret = sr.ReadToEnd()
End Using
End Using
End Using
input = nothing
Catch ex As Exception
EL.AddErr("Encountered an error while decrypting the provided text for " & FName & ". Error Details: " & ex.Message, path)
End Try
Return ret
End Function
EK is my key, which I'll not be including. It's just a String though, nothing special.
I've tried several other methods to decrypt based on guidance on the MSDN site, DreamInCode, etc. None worked, but they all had different issues (typically returning a blank string). Seeing as this version of code closely mirrors my encryption code, I'd like to stick with it (or at least as close as I can while still having functional code).
Despite all comments, I still lack understanding of your intentions. Therefore, the sample code below may not provide what you exactly want, but at least should give an idea how to employ cryptographic functions. Particularly, the most notable difference from your approach is that the encryption key and initialization vector are computed once and for all messages, rather than reevaluated on each occasion, because the latter is prone to synchronization errors — such as when you reuse single crypto object to communicate with multiple parties, or when some messages get lost in transmission.
Public Shared Sub Test()
' Note: You should not actually hard-code any sensitive information in your source files, ever!
Dim sKeyPreimage As String = "MySuperPassword"
Dim oMyCrypto As New MyCrypto(sKeyPreimage)
Dim sPlaintext As String = "My super secret data"
Dim sEncrypted As String = oMyCrypto.EncryptText(sPlaintext)
Dim sDecrypted As String = oMyCrypto.DecryptText(sEncrypted)
Console.Out.WriteLine("Plaintext: {0}", sPlaintext) ' "My super secret data"
Console.Out.WriteLine("Encrypted: {0}", sEncrypted) ' "72062997872DC4B4D1BCBF48D5D30DF0D498B20630CAFA28D584CCC3030FC5F1"
Console.Out.WriteLine("Decrypted: {0}", sDecrypted) ' "My super secret data"
End Sub
Public Class MyCrypto
Private Shared TextEncoding As Text.Encoding = Text.Encoding.UTF8
Private CipherEngine As System.Security.Cryptography.SymmetricAlgorithm
' Note: Unlike in the question, same key and IV are reused for all messages.
Private CipherKey() As Byte
Private CipherIV() As Byte
Public Sub New(ByVal sKeyPreimage As String)
Dim abKeyPreimage() As Byte = TextEncoding.GetBytes(sKeyPreimage)
Dim abKeySalt() As Byte = TextEncoding.GetBytes("Ivan Medvedev")
Const KeyDerivationRounds As Integer = 1 << 12
Dim oKeyDerivationEngine As New System.Security.Cryptography.Rfc2898DeriveBytes(abKeyPreimage, abKeySalt, KeyDerivationRounds)
Me.CipherEngine = System.Security.Cryptography.Aes.Create()
Me.CipherEngine.Padding = Security.Cryptography.PaddingMode.PKCS7
Me.CipherKey = oKeyDerivationEngine.GetBytes(Me.CipherEngine.KeySize >> 3)
Me.CipherIV = oKeyDerivationEngine.GetBytes(Me.CipherEngine.BlockSize >> 3)
End Sub
Public Function Encrypt(ByVal abPlaintext() As Byte) As Byte()
Dim abCiphertext() As Byte
Using hStreamSource As New System.IO.MemoryStream(abPlaintext),
hStreamCipher As New System.Security.Cryptography.CryptoStream(
hStreamSource,
Me.CipherEngine.CreateEncryptor(Me.CipherKey, Me.CipherIV),
Security.Cryptography.CryptoStreamMode.Read),
hStreamTarget As New System.IO.MemoryStream
hStreamCipher.CopyTo(hStreamTarget)
abCiphertext = hStreamTarget.ToArray()
End Using
Return abCiphertext
End Function
Public Function Decrypt(ByVal abCiphertext() As Byte) As Byte()
Dim abPlaintext() As Byte
Using hStreamSource As New System.IO.MemoryStream(abCiphertext),
hStreamCipher As New System.Security.Cryptography.CryptoStream(
hStreamSource,
Me.CipherEngine.CreateDecryptor(Me.CipherKey, Me.CipherIV),
Security.Cryptography.CryptoStreamMode.Read),
hStreamTarget As New System.IO.MemoryStream
hStreamCipher.CopyTo(hStreamTarget)
abPlaintext = hStreamTarget.ToArray()
End Using
Return abPlaintext
End Function
Public Function EncryptText(ByVal sPlaintext As String) As String
Dim abPlaintext() As Byte = TextEncoding.GetBytes(sPlaintext)
Dim abCiphertext() As Byte = Me.Encrypt(abPlaintext)
Dim sCiphertext As String = Hex.Format(abCiphertext)
Return sCiphertext
End Function
Public Function DecryptText(ByVal sCiphertext As String) As String
Dim abCiphertext() As Byte = Hex.Parse(sCiphertext)
Dim abPlaintext() As Byte = Me.Decrypt(abCiphertext)
Dim sPlaintext As String = TextEncoding.GetChars(abPlaintext)
Return sPlaintext
End Function
End Class
Public Class Hex
Public Shared Function Format(ByVal abValue() As Byte) As String
Dim asChars(0 To abValue.Length * 2 - 1) As Char
Dim ndxChar As Integer = 0
For ndxByte As Integer = 0 To abValue.Length - 1
Dim bNibbleHi As Byte = abValue(ndxByte) >> 4, bNibbleLo As Byte = CByte(abValue(ndxByte) And &HFUS)
asChars(ndxChar) = Convert.ToChar(If(bNibbleHi <= 9, &H30US + bNibbleHi, &H37US + bNibbleHi)) : ndxChar += 1
asChars(ndxChar) = Convert.ToChar(If(bNibbleLo <= 9, &H30US + bNibbleLo, &H37US + bNibbleLo)) : ndxChar += 1
Next
Return New String(asChars)
End Function
Public Shared Function Parse(ByVal sValue As String) As Byte()
If String.IsNullOrEmpty(sValue) Then Return New Byte() {}
If (sValue.Length Mod 2) > 0 Then Return Nothing
Dim ndxText As Integer = 0
Dim ndxByteMax As Integer = (sValue.Length \ 2) - 1
Dim abValue(0 To ndxByteMax) As Byte
Try
For ndxByte As Integer = 0 To ndxByteMax
abValue(ndxByte) = Convert.ToByte(sValue.Substring(ndxText, 2), 16)
ndxText += 2
Next
Catch ex As Exception
Return Nothing
End Try
Return abValue
End Function
End Class
Again, please, note that this is just an example. I am not endorsing any kind of protection techniques shown here, especially because your task remains unknown. The code above simply illustrates the syntax and semantics — not how to do it right.

build/check hash value for file

I'm having hard time with this one. Can someone either point me in the right direction for checking/building hash codes for an uploaded file or else tell me what I'm doing wrong with the code below?
getFileSHA256(softwareUpload.PostedFile) 'Line that calls the function includes a reference to an uploaded file
Private Function getFileSHA256(ByVal theFile As Web.HttpPostedFile) As String
Dim SHA256CSP As New SHA256Managed()
Dim byteHash() As Byte = SHA256CSP.ComputeHash(theFile.InputStream)
Return ByteArrayToString(byteHash)
End Function
Private Function ByteArrayToString(ByVal arrInput() As Byte) As String
Dim sb As New System.Text.StringBuilder(arrInput.Length * 2)
For i As Integer = 0 To arrInput.Length - 1
sb.Append(arrInput(i).ToString("X2"))
Next
Return sb.ToString().ToLower
End Function
I should add that the function works, but the return does not match other programs' sha256 values.
EDIT ------
There are two other functions that I'm using in my code. SHA1 gets the same kind of results as the SHA256; the results do not match trusted sources.
However, the MD5 works as expected.
Private Function getFileSHA1(ByVal theFile As Web.HttpPostedFile) As String
Dim SHA1CSP As New SHA1CryptoServiceProvider()
Dim byteHash() As Byte = SHA1CSP.ComputeHash(theFile.InputStream)
Return ByteArrayToString(byteHash)
End Function
Private Function getFileMd5(ByVal theFile As Web.HttpPostedFile) As String
Dim Md5CSP As New System.Security.Cryptography.MD5CryptoServiceProvider
Dim byteHash() As Byte = Md5CSP.ComputeHash(theFile.InputStream)
Return ByteArrayToString(byteHash)
End Function
I plan to consolidate these functions once I know they are working as expected.
The only difference between these is that MD5 is using "MD5CryptoServiceProvider" and it works as expected. SHA1 is also using "SHA1CryptoServiceProvider" but it does not match trusted sources.
I did some testing here, it appears that for text files SHA256Managed works perfectly.
My code is below, I used your implementation of ByteArrayToString:
Sub Main()
Dim s As New SHA256Managed
Dim fileBytes() As Byte = IO.File.ReadAllBytes("s:\sha256.txt")
Dim hash() As Byte = s.ComputeHash(fileBytes)
Dim referenceHash As String = "18ffd9682c5535a2b2798ca51b13e9490df326f185a83fe6e059f8ff47d92105"
Dim calculatedHash As String = ByteArrayToString(hash)
MsgBox(calculatedHash = referenceHash) 'outputs True
End Sub
Private Function ByteArrayToString(ByVal arrInput() As Byte) As String
Dim sb As New System.Text.StringBuilder(arrInput.Length * 2)
For i As Integer = 0 To arrInput.Length - 1
sb.Append(arrInput(i).ToString("X2"))
Next
Return sb.ToString().ToLower
End Function
For testing purposes, I created a file called sha256.txt under S: with the following contents:
my test file
(no trailing spaces or newline)
I got the reference hash value from here, by feeding same data.
Also check this and this - the fact you get non-match could be related to platform and/or implementation of your trusted source, or needing an extra conversion step.

System.Security.Cryptography.HMACSHA1 is Com visible. How should I call ComputeHash?

I want to create an HMAC SHA1 signature of some text in Microsoft Access
The .net object System.Security.Cryptography.HMACSHA1 is com visible, so I thought I could use that.
I can create the object and set the key, but when I come to call the compute function to get the hash, I am getting the error run time error 5 "Invalid Procedure Call or Argument"
Public Function sign(Key As String, Message As String)
Dim asc, enc
Dim MessageBytes() As bytes, HashBytes() As bytes
Set asc = CreateObject("System.Text.UTF8Encoding")
Set enc = CreateObject("System.Security.Cryptography.HMACSHA1")
enc.Key = asc.GetBytes_4(Key)
MessageBytes = asc.GetBytes_4(Message)
HashBytes = enc.ComputeHash(MessageBytes)
sign = EncodeBase64(HashBytes)
Set asc = Nothing
Set enc = Nothing
End Function
I copied the Encoding bit from the web and I note there that GetBytes has transmuted into GetBytes_4. Is this name mangling? and do I need to do something similar to ComputeHash? and if so what (I tried _n where n = 1 to 6 to no avail).
If not What am I doing wrong?
I found the answer to my question in this question
Base64 HMAC SHA1 String in VBA
I thought I had tried enc.ComputeHash_2, but maybe I didn't because it seems to work

Mixed Encoding to String

I have a string in VB.net that may contain something like the following:
This is a 0x000020AC symbol
This is the UTF-32 encoding for the Euro Symbol according to this article http://www.fileformat.info/info/unicode/char/20ac/index.htm
I'd like to convert this into
This is a € symbol
I've tried using UnicodeEncoding() class in VB.net (Framework 2.0, as I'm modifying a legacy application)
When I use this class to encode, and then decode I still get back the original string.
I expected that the UnicodeEncoding would recognise the already encoded part and not encode it against. But it appears to not be the case.
I'm a little lost now as to how I can convert a mixed encoded string into a normal string.
Background: When saving an Excel spreadsheet as CSV, anything outside of the ascii range gets converted to ?. So my idea is that if I can get my client to search/replace a few characters, such as the Euro symbol, into an encoded string such as 0x000020AC. Then I was hoping to convert those encoded parts back into the real symbols before I insert to a SQL database.
I've tried a function such as
Public Function Decode(ByVal s As String) As String
Dim uni As New UnicodeEncoding()
Dim encodedBytes As Byte() = uni.GetBytes(s)
Dim output As String = ""
output = uni.GetString(encodedBytes)
Return output
End Function
Which was based on the examples on the MSDN at http://msdn.microsoft.com/en-us/library/system.text.unicodeencoding.aspx
It could be that I have a complete mis-understanding of how this works in VB.net. In C# I can simply use escaped characters such as "\u20AC". But no such thing exists in VB.net.
Based on advice from Heinzi I implemented a Regex.Replace method using the following code, this appear to work for my examples.
Public Function Decode(ByVal s As String) As String
Dim output As String = ""
Dim sRegex As String = "0x[0-9a-zA-Z]{8}"
Dim r As Regex = New Regex(sRegex)
Dim myEvaluator As MatchEvaluator = New MatchEvaluator(AddressOf HexToString)
output = r.Replace(s, myEvaluator)
Return output
End Function
Public Function HexToString(ByVal hexString As Match) As String
Dim uni As New UnicodeEncoding(True, True)
Dim input As String = hexString.ToString
input = input.Substring(2)
input = input.TrimStart("0"c)
Dim output As String
Dim length As Integer = input.Length
Dim upperBound As Integer = length \ 2
If length Mod 2 = 0 Then
upperBound -= 1
Else
input = "0" & input
End If
Dim bytes(upperBound) As Byte
For i As Integer = 0 To upperBound
bytes(i) = Convert.ToByte(input.Substring(i * 2, 2), 16)
Next
output = uni.GetString(bytes)
Return output
End Function
Have you tried:
Public Function Decode(Byval Coded as string) as string
Return StrConv(Coded, vbUnicode)
End Function
Also, your function is invalid. It takes s as an argument, does a load of stuff and then outputs the s that was put into it instead of the stuff that was processed within it.