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Ed25519ph Sign and Verify

See more Ed25519 Examples

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

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

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Dim success As Boolean
success = False

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

Dim privKey As New Chilkat.PrivateKey
success = privKey.LoadEd25519(privKeyHex,pubKeyHex)
If (success = False) Then
    System.DebugLog(privKey.LastErrorText)
    Return
End If

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

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

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

System.DebugLog("signature = " + hexSig)

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

// Verify the signature..
Dim pubKey As New Chilkat.PublicKey
success = pubKey.LoadEd25519(pubKeyHex)
If (success = False) Then
    System.DebugLog(pubKey.LastErrorText)
    Return
End If

Dim bVerified As Boolean
bVerified = eddsa.VerifyBdENC(bd,hexSig,"hexlower",pubKey)
If (bVerified = False) Then
    System.DebugLog(eddsa.LastErrorText)
    System.DebugLog("Failed to verify the signature.")
    Return
End If

System.DebugLog("The Ed25519ph signature is verified!")