(Visual FoxPro) Create PKCS1 RSA Signature with PEM Private Key

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loPkey
LOCAL lnSuccess
LOCAL lcPkeyXml
LOCAL loRsa
LOCAL lnSuccess
LOCAL lcStrData
LOCAL lcHexSig

loPkey = CreateObject('Chilkat_9_5_0.PrivateKey')

*  Load the private key from an RSA PEM file:
lnSuccess = loPkey.LoadPemFile("pvkey2_rsa.pem")

*  Get the private key in XML format:
lcPkeyXml = loPkey.GetXml()

loRsa = CreateObject('Chilkat_9_5_0.Rsa')

*  Any string argument automatically begins the 30-day trial.
lnSuccess = loRsa.UnlockComponent("30-day trial")
IF (lnSuccess <> 1) THEN
    ? "RSA component unlock failed"
    RELEASE loPkey
    RELEASE loRsa
    CANCEL
ENDIF

*  Import the private key into the RSA component:
lnSuccess = loRsa.ImportPrivateKey(lcPkeyXml)
IF (lnSuccess <> 1) THEN
    ? loRsa.LastErrorText
    RELEASE loPkey
    RELEASE loRsa
    CANCEL
ENDIF

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

*  If some other non-Chilkat software is going to verify
*  the signature, it is important to match the byte-ordering.
*  The LittleEndian property may be set to 1
*  for little-endian byte ordering,
*  or 0  for big-endian byte ordering.
*  Microsoft apps typically use little-endian, while
*  OpenSSL and other services (such as Amazon CloudFront)
*  use big-endian.
loRsa.LittleEndian = 0

lcStrData = "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".
lcHexSig = loRsa.SignStringENC(lcStrData,"sha-1")

? lcHexSig

? "Success!"

RELEASE loPkey
RELEASE loRsa