CkPython

RSAES-OAEP Encrypt String with AES-128 Content Encryption and SHA256

See more Encryption Examples

Encrypts a string using RSAES-OAEP with SHA256 and AES-128 content encryption to produce PKCS7 output (base64 encoded).

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

CkPython

import sys
import chilkat

success = False

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

# First build a string to be encrypted
sb = chilkat.CkStringBuilder()
i = 1
while i < 25 :
    sb.AppendInt(i)
    sb.Append(" the quick brown fox jumped over the lazy dog.\r\n")
    i = i + 1

print(sb.getAsString())

# The string to be encrypted looks like this:

# 1 the quick brown fox jumped over the lazy dog.
# 2 the quick brown fox jumped over the lazy dog.
# 3 the quick brown fox jumped over the lazy dog.
# 4 the quick brown fox jumped over the lazy dog.
# 5 the quick brown fox jumped over the lazy dog.
# 6 the quick brown fox jumped over the lazy dog.
# ...

# Load a digital certificate. 
# We don't need the private key for encryption.
# Only the public key is needed (which is included in a certificate).
cert = chilkat.CkCert()
success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
if (success != True):
    print(cert.lastErrorText())
    sys.exit()

crypt = chilkat.CkCrypt2()

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

# Indicate that we want PKI encryption (i.e. public-key infrastructure)
# to produce a CMS message (Cryptographic Message Syntax/PKCS7),
# that is be created with RSAES-OAEP padding, SHA256, and AES-128 for the
# bulk encryption.
crypt.put_CryptAlgorithm("pki")
crypt.put_Pkcs7CryptAlg("aes")
crypt.put_KeyLength(128)
crypt.put_OaepHash("sha256")
crypt.put_OaepPadding(True)

# Also, don't forget to be specific about the character encoding (byte representation) of the
# string to be encrypted.
crypt.put_Charset("utf-8")

# Now indicate that the PKCS7 output is to be returned in the base64 encoding.
crypt.put_EncodingMode("base64")

base64Pkcs7 = crypt.encryptStringENC(sb.getAsString())
if (crypt.get_LastMethodSuccess() != True):
    print(crypt.lastErrorText())
    sys.exit()

# Show the output
print(base64Pkcs7)

# This base64 can be copy-and-pasted into the form at http://lapo.it/asn1js/
# to verify that all the chosen algorithms were indeed used.

print("OK.")