Command line tools and libraries for encrypting keys and values using client-side encryption with AWS KMS keys.
The easiest installation method is the Python package from PyPI:
pip install nitor-vaultJavascript and Java versions are available from npm and maven central respectively and installation will depend on your needs.
Initialize a vault bucket and other infrastructure: vault --init.
This will create a CloudFormation stack.
Encrypt a file and store in vault bucket: vault -s my-key -f <file>
Decrypt a file: vault -l <file>
Encrypt a single value and store in vault bucket vault -s my-key -v my-value
Decrypt a single value vault -l my-key
Encrypt a value like this: vault -e 'My secret value'
The command above will print the base64 encoded value encrypted with your vault KMS key. Use that value in a CF parameter. The value is then also safe to commit into version control and you can use it in scripts for example like this:
#!/bin/bash
MY_ENCRYPTED_SECRET="AQICAHhu3HREZVp0YXWZLoAceH1Nr2ZTXoNZZKTriJY71pQOjAHKtG5uYCdJOKYy9dhMEX03AAAAbTBrBgkqhkiG9w0BBwagXjBcAgEAMFcGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMYy/tKGJFDQP6f9m1AgEQgCq1E1q8I+btMUdwRK8wYFNyE/5ntICNM96VPDnYbeTgcHzLoCx+HM1cGvc"
UNENCRYPTED_SECRET="$(vault -y $MY_ENCRYPTED_SECRET)"Obviously you need to make sure that in the context of running the vault, there is some sort of way for providing KMS permissions by for example adding the decryptPolicy managed policy from the vault Cloudformation stack to the EC2 instance or whatever runs the code.
To decrypt the parameter value at stack creation or update time, use a custom resource:
Parameters:
MySecret:
Type: String
Description: Param value encrypted with KMS
Resources:
DecryptSecret:
Type: "Custom::VaultDecrypt"
Properties:
ServiceToken: "arn:aws:lambda:<region>:<account-id>:function:vault-decrypter"
Ciphertext: { "Ref": "MySecret" }
DatabaseWithSecretAsPassword:
Type: "AWS::RDS::DBInstance"
Properties:
...
MasterUserPassword:
Fn::Sub: ${DecryptSecret.Plaintext}