Chilkat2-Python

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.

Chilkat2-Python

import sys
import chilkat2

success = False

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

pkey = chilkat2.PrivateKey()

# Load the private key from an PEM file:
success = pkey.LoadPemFile("private.pem")
if (success == False):
    print(pkey.LastErrorText)
    sys.exit()

rsa = chilkat2.Rsa()

# Import the private key into the RSA component:
success = rsa.UsePrivateKey(pkey)
if (success == False):
    print(rsa.LastErrorText)
    sys.exit()

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

# Load the file to be signed.
bdFileData = chilkat2.BinData()
success = bdFileData.LoadFile("in.dat")

bdSig = chilkat2.BinData()
success = rsa.SignBd(bdFileData,"sha256",bdSig)
if (success == False):
    print(rsa.LastErrorText)
    sys.exit()

# Save the binary signature to a file.
success = bdSig.WriteFile("signature.sig")
if (success != True):
    print("Failed to write signature.sig.")
    sys.exit()

print("Success.")