RSA Sign with PKCS8 Encrypted Key

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature.

Download Chilkat .NET for 4.0 Framework

Download Chilkat .NET for 64-bit 4.0 Framework (x64)

Download Chilkat .NET for 2.0 / 3.5 Framework

Download Chilkat .NET for 64-bit 2.0 / 3.5 Framework (x64)

Download Chilkat .NET for 1.0 / 1.1 Framework

Dim pkey As New Chilkat.PrivateKey()

'  Load the private key from an RSA PEM file:
pkey.LoadPkcs8EncryptedFile("privateKey.key","myPassword")

Dim success As Boolean

Dim pkeyXml As String
'  Get the private key in XML format:
pkeyXml = pkey.GetXml()

Dim rsa As New Chilkat.Rsa()

'  Any string argument automatically begins the 30-day trial.

success = rsa.UnlockComponent("30-day trial")
If (success <> true) Then
    MsgBox("RSA component unlock failed")
    Exit Sub
End If


'  Import the private key into the RSA component:
success = rsa.ImportPrivateKey(pkeyXml)
If (success <> true) Then
    MsgBox(rsa.LastErrorText)
    Exit Sub
End If


'  This example will sign a string, and receive the signature
'  in a hex-encoded string.  Therefore, set the encoding mode
'  to "hex":
rsa.EncodingMode = "hex"

'  If some other non-Chilkat application or web service is going to be verifying
'  the signature, it is important to match the byte-ordering.
'  The LittleEndian property may be set to True
'  for little-endian byte ordering,
'  or False  for big-endian byte ordering.
'  Microsoft apps typically use little-endian, while
'  OpenSSL and other services (such as Amazon CloudFront)
'  use big-endian.
rsa.LittleEndian = false

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

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

TextBox1.Text = TextBox1.Text & hexSig & vbCrLf