aes_gcm encryption

gistfile1.txt

from Crypto.Cipher import AES
import binascii, os

def encrypt_AES_GCM(msg, secretKey):
    aesCipher = AES.new(secretKey, AES.MODE_GCM)
    ciphertext, authTag = aesCipher.encrypt_and_digest(msg)
    print("ciphertext: {}, authTag: {}".format(ciphertext, authTag))
    return (ciphertext, aesCipher.nonce, authTag)

def decrypt_AES_GCM(encryptedMsg, secretKey):
    (ciphertext, nonce, authTag) = encryptedMsg
    aesCipher = AES.new(secretKey, AES.MODE_GCM, nonce)
    plaintext = aesCipher.decrypt_and_verify(ciphertext, authTag)
    return plaintext

# secretKey = os.urandom(16)  # 128-bit random encryption key
# print("Encryption key:", binascii.hexlify(secretKey))
secretKey = binascii.hexlify('fooofooofoopfooo'.encode('utf-8'))
print("Encryption key:", secretKey)

msg = b'ultra secret message'
encryptedMsg = encrypt_AES_GCM(msg, secretKey)
print("encryptedMsg", {
    'ciphertext': inascii.hexlify(encryptedMsg[0]),
    'aesIV': binascii.hexlify(encryptedMsg[1]),
    'authTag': binascii.hexlify(encryptedMsg[2])
})

decryptedMsg = decrypt_AES_GCM(encryptedMsg, secretKey)
print("decryptedMsg", decryptedMsg)