Visual FoxPro

Duplicate openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

See more OpenSSL Examples

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -sign private.pem -out sha256.sig in.dat

The in.dat file can contain text or binary data of any type. The OpenSSL command does the following:

1. Creates a SHA256 digest of the contents of the input file
2. Signs the SHA256 digest using the private key.

Visual FoxPro

LOCAL lnSuccess
LOCAL loPkey
LOCAL loRsa
LOCAL loBdFileData
LOCAL loBdSig

lnSuccess = 0

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

loPkey = CreateObject('Chilkat.PrivateKey')

* Load the private key from an PEM file:
lnSuccess = loPkey.LoadPemFile("private.pem")
IF (lnSuccess = 0) THEN
    ? loPkey.LastErrorText
    RELEASE loPkey
    CANCEL
ENDIF

loRsa = CreateObject('Chilkat.Rsa')

* Import the private key into the RSA component:
lnSuccess = loRsa.UsePrivateKey(loPkey)
IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loPkey
    RELEASE loRsa
    CANCEL
ENDIF

* OpenSSL uses big-endian.
loRsa.LittleEndian = 0

* Load the file to be signed.
loBdFileData = CreateObject('Chilkat.BinData')
lnSuccess = loBdFileData.LoadFile("in.dat")

loBdSig = CreateObject('Chilkat.BinData')
lnSuccess = loRsa.SignBd(loBdFileData,"sha256",loBdSig)
IF (lnSuccess = 0) THEN
    ? loRsa.LastErrorText
    RELEASE loPkey
    RELEASE loRsa
    RELEASE loBdFileData
    RELEASE loBdSig
    CANCEL
ENDIF

* Save the binary signature to a file.
lnSuccess = loBdSig.WriteFile("signature.sig")
IF (lnSuccess <> 1) THEN
    ? "Failed to write signature.sig."
    RELEASE loPkey
    RELEASE loRsa
    RELEASE loBdFileData
    RELEASE loBdSig
    CANCEL
ENDIF

? "Success."

RELEASE loPkey
RELEASE loRsa
RELEASE loBdFileData
RELEASE loBdSig