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

Demonstrates how to duplicate this OpenSSL command:

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

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

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

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

pkey = Chilkat::CkPrivateKey.new()

# Load the private key from an PEM file:
success = pkey.LoadPemFile("private.pem")
if (success != true)
    print pkey.lastErrorText() + "\n";
    exit
end

rsa = Chilkat::CkRsa.new()

# Import the private key into the RSA component:
success = rsa.ImportPrivateKeyObj(pkey)
if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

# OpenSSL uses big-endian.
rsa.put_LittleEndian(false)

# Load the file to be signed.
bdFileData = Chilkat::CkBinData.new()
success = bdFileData.LoadFile("in.dat")

bdSig = Chilkat::CkBinData.new()
success = rsa.SignBd(bdFileData,"sha256",bdSig)
if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

# Save the binary signature to a file.
success = bdSig.WriteFile("signature.sig")
if (success != true)
    print "Failed to write signature.sig." + "\n";
    exit
end

print "Success." + "\n";