B4X Requires Chilkat v11.0.0+

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.

B4X

Dim success As Boolean = False

'  This example requires 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 PEM file:
success = pkey.LoadPemFile("private.pem")
If success = False Then
    Log(pkey.LastErrorText)
    Return
End If


Dim rsa As ChilkatRsa
rsa.Initialize

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


'  OpenSSL uses big-endian.
rsa.LittleEndian = False

'  Load the file to be signed.
Dim bdFileData As ChilkatBinData
bdFileData.Initialize
success = bdFileData.LoadFile("in.dat")

Dim bdSig As ChilkatBinData
bdSig.Initialize
success = rsa.SignBd(bdFileData, "sha256", bdSig)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


'  Save the binary signature to a file.
success = bdSig.WriteFile("signature.sig")
If success <> True Then
    Log("Failed to write signature.sig.")
    Return
End If


Log("Success.")