mrcrypt is a command-line tool which encrypts secrets that conform to the AWS Encryption SDK's message format for envelope encryption. Envelope encryption is used to encrypt a file using a KMS data key. That data key is then encrypted with regional KMS Customer Master Keys. Each regionally encrypted data key is then stored in the encrypted message. When decrypting, the appropriate regional CMK is used to decrypt the data key, and the data key is then used to decrypt the file. In other words, encrypt once - decrypt from anywhere.
mrcrypt is compatible with the AWS Encryption SDK message format. For details, see the section titled Compatibility with the AWS Encryption SDK.
You can install the latest release of mrcrypt with pip:
pip install mrcrypt
Note: mrcrypt uses the Python package
Cryptography which depends on
libffi. You may need to install it on your system if
pip install . fails. For more specific instructions for your OS:
https://cryptography.io/en/latest/installation/
Encrypt a file for use in 3 regions (NOTE: Key alias must exist in specified regions):
mrcrypt encrypt -r us-east-1 us-west-2 eu-west-1 -- alias/master-key secrets.txt
Decrypt the file:
mrcrypt decrypt secrets.txt.encrypted
usage: mrcrypt [-h] [-p PROFILE] [-e ENCRYPTION_CONTEXT] [-d] [-o OUTFILE]
{encrypt,decrypt} ...
Multi Region Encryption. A tool for managing secrets across multiple AWS
regions.
positional arguments:
{encrypt,decrypt}
optional arguments:
-h, --help show this help message and exit
-p PROFILE, --profile PROFILE
The profile to use
-e ENCRYPTION_CONTEXT, --encryption_context ENCRYPTION_CONTEXT
An encryption context to use. (Cannot have whitespace)
-d, --debug Enable more output for debugging
-o OUTFILE, --outfile OUTFILE
The file to write the results to
Both the encrypt, and decrypt commands can encrypt and decrypt files in directories recursively.
If you have multiple named profiles in your ~/.aws/credentials file,
you can specify one using the -p argument.
mrcrypt -p my_profile encrypt alias/master-key secrets.txt
You can specify an encryption
context
using the -e argument. This flag takes a JSON object with no spaces:
# encrypt
mrcrypt -e '{"key":"value","key2":"value2"}' encrypt alias/master-key secrets.txt
# decrypt
mrcrypt -e '{"key":"value","key2":"value2"}' decrypt secrets.txt.encrypted
If you want to specify the output filename, you can use the -o
argument.
# Encrypt 'file.txt' writing the output into 'encrypted-file.txt' mrcrypt -o encrypted-file.txt encrypt alias/master-key file.txt
When an output filename is not specified, mrcrypt will use the input
filename as a base and add a suffix. On encrypt this suffix is .encrypted
and on decrypt this suffix is .decrypted.
usage: mrcrypt encrypt [-h] [-r REGIONS [REGIONS ...]] [-e ENCRYPTION_CONTEXT]
key_id filename
Encrypts a file or directory recursively
positional arguments:
key_id An identifier for a customer master key.
filename The file or directory to encrypt. Use a - to read from
stdin
optional arguments:
-h, --help show this help message and exit
-r REGIONS [REGIONS ...], --regions REGIONS [REGIONS ...]
A list of regions to encrypt with KMS. End the list
with --
-e ENCRYPTION_CONTEXT, --encryption_context ENCRYPTION_CONTEXT
An encryption context to use
Example: Encrypt secrets.txt with the key alias
alias/master-key in the regions us-east-1 and us-west-2:
mrcrypt encrypt -r us-east-1 us-west-2 -- alias/master-key secrets.txt
Note: In this example, the key alias alias/master-key exists in both the us-east-1, and us-west-2 regions.
usage: mrcrypt decrypt [-h] filename Decrypts a file positional arguments: filename The file or directory to decrypt. Use a - to read from stdin optional arguments: -h, --help show this help message and exit
Example: To decrypt secrets.txt.encrypted:
mrcrypt decrypt secrets.txt.encrypted
Note: Be careful when decrypting a directory. If the directory contains files that are not encrypted, it will fail.
Running tests for mrcrypt is easy if you have tox installed. Simply
run tox at the project's root.
From v1.2.0 on, all files encrypted with mrcrypt can be decrypted with any AWS Encryption SDK client. v1.2.0+ is backwards compatible with files generated by earlier versions of, but earlier versions of mrcrypt cannot decrypt files generated by v1.2.0+.