B4X Requires Chilkat v11.0.0+

Create PKCS1 RSA Signature with PEM Private Key

See more RSA Examples

Demonstrates how to load a private key from a PEM file and create a PKCS1 RSA digital signature. B4X

Dim success As Boolean = False

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

Dim pkey As ChilkatPrivateKey
pkey.Initialize("pkey")

'  Load the private key from an RSA PEM file:
success = pkey.LoadPemFile("pvkey2_rsa.pem")
If success = False Then
    Log(pkey.LastErrorText)
    Return
End If


Dim rsa As ChilkatRsa
rsa.Initialize

'  Import the private key into the RSA object:
success = rsa.UsePrivateKey(pkey)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


'  Get the signature as hex.
rsa.EncodingMode = "hex"

Dim strData As String = "This is the string to be signed."

'  Sign the string using the sha-1 hash algorithm.
'  Other valid choices are "md2", "md5", "sha256",
'  "sha384", and "sha512".
Dim hexSig As String = rsa.SignStringENC(strData, "sha-1")

Log(hexSig)

Log("Success!")