Chilkat2-Python

Duplicate openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

See more OpenSSL Examples

Demonstrates how to duplicate this OpenSSL command:

openssl dgst -sha256 -verify pubKey.pem -signature signature.sig in.dat

The in.dat file contains the original data that was signed, and can contain text or binary data of any type. The above OpenSSL command does the following:

1. Creates a SHA256 digest of the contents of the input file.
2. Verifies the SHA256 digest using the public 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.

pubKey = chilkat2.PublicKey()

# Load the public key from an PEM file:
success = pubKey.LoadFromFile("pubKey.pem")
if (success == False):
    print(pubKey.LastErrorText)
    sys.exit()

# Load the data of the original file that was signed.
bdFileData = chilkat2.BinData()
success = bdFileData.LoadFile("in.dat")

# Load the signature.
bdSig = chilkat2.BinData()
success = bdSig.LoadFile("signature.sig")

rsa = chilkat2.Rsa()

# Import the public key into the RSA component:
success = rsa.UsePublicKey(pubKey)
if (success == False):
    print(rsa.LastErrorText)
    sys.exit()

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

success = rsa.VerifyBd(bdFileData,"sha256",bdSig)
if (success != True):
    print(rsa.LastErrorText)
    print("The signature was invalid.")
    sys.exit()

print("The signature was verified.")