This command line tool can be used to encrypt and decrypt files and directories using the AWS Encryption SDK. If you have not already installed cryptography, you might need to install additional prerequisites as detailed in the cryptography installation guide for your operating system. Installation using a python virtual environment is recommended to avoid conflicts between system packages and user-installed packages.
Command line tool for managing Amazon S3 and CloudFront services
...Lots of features and options have been added to S3cmd, since its very first release in 2008.... we recently counted more than 60 command-line options, including multipart uploads, encryption, incremental backup, s3 sync, ACL and Metadata management, S3 bucket size, bucket policies, and more!