kmstool

kmstool helps you encrypt data using the Amazon Key Management Service in AWS.

Installing

pip install .

Usage

kmstool has two modes: pack and unpack

store

kmstool pack <key_id> <source>

This command takes a KMS key ID, produces a data key, and uses that key to encrypt the file . An encrypted copy of the data key is stored, along with the encrypted files, in the current directory.

retrieve

kmstool retrieve <source>

This command reads the contents of passing the encrypted data key to KMS, and using the resulting plaintext key to decrypt the original data. The files are extracted to the current directory.

Additional Options

Additional options are available: see kmstool -h for usage information.

Unless otherwise specified, AWS credentials are determined by first examining the environment, then a search of the AWS metadata service, and finally using the "default" botocore profile.

--profile
    AWS (botocore) profile to use when contacting the KMS.
--region
    AWS region to connect to for KMS.

An optional encryption context may be passed when storing files. The same context must be passed when retrieving them.

-c --encryption-context foo=bar,baz=qux

Internals

The output of kmstool pack is a gzipped GNU tar file containing the KMS-encrypted data key plus an encrypted tar.gz of the source data. The encrypted data is stored as follows (numbers are byte offsets).

0-15 Initialization Vector
16-N Encrypted data:
     0-15 Original filesize
     16-N Original data

Cryptography install on Mac

If you have issues with installing cryptography library on Mac out of the box, make sure that you've upgraded your pip

pip install -U pip