(VB.NET UWP/WinRT) Ed25519ph Sign and Verify

Demonstrates how to create an Ed25519ph signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.91 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' Use the following test vector from https://www.rfc-editor.org/rfc/rfc8032#page-30

'    -----TEST abc
' 
'    ALGORITHM:
'    Ed25519ph
' 
'    SECRET KEY:
'    833fe62409237b9d62ec77587520911e
'    9a759cec1d19755b7da901b96dca3d42
' 
'    PUBLIC KEY:
'    ec172b93ad5e563bf4932c70e1245034
'    c35467ef2efd4d64ebf819683467e2bf
' 
'    MESSAGE (length 3 bytes):
'    616263
' 
'    SIGNATURE:
'    98a70222f0b8121aa9d30f813d683f80
'    9e462b469c7ff87639499bb94e6dae41
'    31f85042463c2a355a2003d062adf5aa
'    a10b8c61e636062aaad11c2a26083406

Dim privKeyHex As String = "833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42"
Dim pubKeyHex As String = "ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf"

Dim privKey As New Chilkat.PrivateKey
Dim success As Boolean = privKey.LoadEd25519(privKeyHex,pubKeyHex)
If (success = False) Then
    Debug.WriteLine(privKey.LastErrorText)
    Exit Sub
End If


' The data to be signed...
Dim bd As New Chilkat.BinData
bd.AppendEncoded("616263","hex")

Dim eddsa As New Chilkat.EdDSA
' Indicate we want the Ed25519ph instance.
eddsa.Algorithm = "Ed25519ph"

Dim hexSig As String = eddsa.SignBdENC(bd,"hexlower",privKey)

Debug.WriteLine("signature = " & hexSig)

' The expected output is: 98a70222f0b8121aa9d30f813d683f80....

' Verify the signature..
Dim pubKey As New Chilkat.PublicKey
success = pubKey.LoadEd25519(pubKeyHex)
If (success = False) Then
    Debug.WriteLine(pubKey.LastErrorText)
    Exit Sub
End If


Dim bVerified As Boolean = eddsa.VerifyBdENC(bd,hexSig,"hexlower",pubKey)
If (bVerified = False) Then
    Debug.WriteLine(eddsa.LastErrorText)
    Debug.WriteLine("Failed to verify the signature.")
    Exit Sub
End If



Debug.WriteLine("The Ed25519ph signature is verified!")