Visual Basic 6.0

RSA Hash Binary Data and Sign (and Verify)

See more RSA Examples

Demonstrates how to sign the hash of binary data. Also demonstrates how to verify the RSA signature. Visual Basic 6.0

Dim success As Long
success = 0

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

' Load an RSA private key for signing.
Dim privKey As New PrivateKey
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
If (success = 0) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

Dim rsa As New ChilkatRsa
success = rsa.UsePrivateKey(privKey)

' We have some binary data (in hex) to sign
Dim originalData As String
originalData = "0102030405060708090A"
Dim bdData As New ChilkatBinData
success = bdData.AppendEncoded(originalData,"hex")

' Hash (SHA-256) and sign the hash:
Dim bdSignature As New ChilkatBinData
success = rsa.SignBd(bdData,"sha256",bdSignature)
If (success = 0) Then
    Debug.Print rsa.LastErrorText
    Exit Sub
End If

' Show the RSA signature in base64
Debug.Print bdSignature.GetEncoded("base64")

' ------------------------------------------
' Get the public key from the private key
Dim pubKey As New PublicKey
success = privKey.ToPublicKey(pubKey)

' Verify the signature..
Dim rsa2 As New ChilkatRsa
success = rsa2.UsePublicKey(pubKey)

Dim bVerified As Long
bVerified = rsa2.VerifyBd(bdData,"sha256",bdSignature)
Debug.Print "signature verified: " & bVerified