(CkPython) RSAES-OAEP Encrypt/Decrypt Binary Data with AES-128 and SHA56

Demonstrates the use of the new EncryptBd and DecryptBd methods introduced in Chilkat v9.5.0.67 to create a PKCS7/CMS (Cryptographic Message Syntax) message using RSAES-OAEP with AES-128 and SHA256.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

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

# Load a small JPG file to be encrypted/decrypted.
jpgBytes = chilkat.CkBinData()
success = jpgBytes.LoadFile("qa_data/jpg/starfish20.jpg")
if (success != True):
    print("Failed to load JPG file.")
    sys.exit()

# Show the unencrypted JPG bytes in Base64 format.
# (The "base64_mime" encoding was added in Chilkat v9.5.0.67.
# The "base64" encoding emits a single line of base64, whereas
# "base64_mime" will emit multi-line base64 as it would appear
# in MIME.)
print(jpgBytes.getEncoded("base64_mime"))

# Sample base64_mime JPG data:

# /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
# NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
# YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
# Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
# AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
# NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
# pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
# Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
# enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
# xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
# DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
# AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
# QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
# EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==

crypt = chilkat.CkCrypt2()

# Specify the encryption to be used.
# "pki" indicates "Public Key Infrastructure" and will create a PKCS7/CMS message.
crypt.put_CryptAlgorithm("pki")
crypt.put_Pkcs7CryptAlg("aes")
crypt.put_KeyLength(128)
crypt.put_OaepHash("sha256")
crypt.put_OaepPadding(True)

# A certificate is needed as the encryption key..
cert = chilkat.CkCert()
success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
if (success != True):
    print(cert.lastErrorText())
    sys.exit()

# Tell the crypt object to use the certificate.
crypt.SetEncryptCert(cert)

# Do the in-place RSAES-OAEP encryption.
# The contents of jpgBytes are replaced with the CMS message.
success = crypt.EncryptBd(jpgBytes)
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

# Examine the JPG bytes again.  The bytes should be different because they are encrypted:
print(jpgBytes.getEncoded("base64_mime"))

# Sample CMS message:
# This CMS message can be copy-and-pasted into the online web form
# at https://lapo.it/asn1js/   to verify the algorithms used.

# MIIFDAYJKoZIhvcNAQcDoIIE/TCCBPkCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
# CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
# dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
# oA0wCwYJYIZIAWUDBAIBBIIBAHyWLgkJfIvoA3cYEAR/uHfA7uoi4eQXHl2woQAd6W5BbUNVBcYD
# zuCTTOTWo1e7Uh0j0AhMZvVQf3+cngTiimzKwIZ2LNuNAgYOhrO/7coHyB22ImVetncUpCsAv/u7
# 2tYp1dO36T56K+2hMELwcQXTj6v5ODO6a3emdCjITCjHhlYePvq2l0HyU2ALG5RFB6ldk9imhKzn
# 6gfcijfH65S+KfMRlFBCXFu5nCBKmi8Ywo8Ue0rFssUDKLCjCeQNY52symiDbN/d06K/luOUwVhY
# 1KQffdIKmTrZUugw+FaoQRq0xGj39T/sYu8qCinNZu/vPdUmxcXszSaSVJ/LGwcwggNOBgkqhkiG
# 9w0BBwEwHQYJYIZIAWUDBAECBBDLnqRASqqnNUV2IiDkTRl/gIIDIPRaxdKEjhR5RD7pc7yI5j7N
# TioZNvuMETdHWgHy7eOGz+1hP7fObk/RI0mtQx7IPEjkxaduNbXNzTpXAVRVj4Fw1zzXlqh9UPwt
# p3TN3NsVRPQ5GmQ+cnPTSZD8i3i8ru8WFHyj1M6vyA0phrEGltKgqsZbb+OkuO5qG3laJv4XGkmn
# 039pPGSTydQzW+HAp/hsJZLEMwdngXToi854ytjEk+ahCkeOz+d2MAfXZAR+nBCkmAmCQ9SDVTqH
# FVJOAV2WrKBqNv4+iMn63f7QeoVIjk0QTE8D2iRsUiFYjy4ICaUpplLJEewneH5l0W40KA2+mOep
# lIrvWnaX2H8ltOEBGD6Jng7i6p/Q4Lr+Y+HBYIHsBPLox3A4NOh/b0MZcyBr/AV2CsIwkIUGLlYl
# /3rnpl7dRTuHP+fe1lDQVLAxD+U0c73sW7vOALhEe2t2Ae3ayukWPRyfXK9FNHAMhcOI4stHNSwx
# o2fHa+ctTpPh0V5CHY/ELAKKkrH3nW954pk52tc8Xt6CnzVO5ry/ndcmTlQA0PkG6CK98TE9hCTA
# hBdSL4/gVFgi9c35I6VXieY9kJe5ICljw5Ftm5yqTwlJIxGU3Z/WeIYBF4uyMegG75AQ9Md9tX0h
# w8OOu2b6sIvxOZ+durIrYQDlXUXU/IR9exzAlYFENNBPhBgtDsWKSx5gcp+32kC5wtSYSiy3JxNt
# 0W1yEJz8JGZXhuUvRXjwf+AjS4+/o82WTNXVLVKZ0TP50NVvtf9QqWuXvK/kDDPx6w+abK/aqdAs
# QSL7wCxOosR2YUPWbXtwGhyHbIfAwWXijO2RnrqKeXL25Ywg16LQUTHq9Mlbgfw/tx3l5pjrmqFC
# e9t9aaU6kDZqyyfRDOeWwkuDIsT90ulazbed2apgUXYj6AVVvMiC1pRld9wSuHH0vW0x5VsNbmXy
# EY0NJlJY6II/1szy3bpiP6MsqFveCyCX8rM7UgGgpMNbvWPnsX0F/0eJywIrXrnQYXpvfgghIrlr
# qu/ftXWypfcfvATxme+cN2EBsCDhq4VcMgB6JY3ykv6P8PK/QpMTbu4Y

# To decrypt, we'll need the cert with private key.  
# (The certificate alone contains only the public key.)
# Provide the required cert + private key from a PFX (.pfx/.p12) file.
success = crypt.AddPfxSourceFile("qa_data/rsaes-oaep/cert_plus_privatekey.pfx","PFX_PASSWORD")
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

# Decrypt to restore back to the original:
success = crypt.DecryptBd(jpgBytes)
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

print(jpgBytes.getEncoded("base64_mime"))