SFTPGo stores sensitive data such as Cloud account credentials or passphrases to derive per-object encryption keys. These data are stored as ciphertext and only loaded to RAM in plaintext when needed.
The secrets
section of the kms
configuration allows to configure how to encrypt and decrypt sensitive data. The following configuration parameters are available:
url
defines the URI to the KMS servicemaster_key
, defines the master encryption key as string. If not empty, it takes precedence over master_key_path
.master_key_path
defines the absolute path to a file containing the master encryption key. This could be, for example, a docker secret or a file protected with filesystem level permissions.If the url
is empty SFTPGo uses local encryption for keeping secrets. Internally, it uses the NaCl secret box algorithm to perform encryption and authentication.
We first generate a random key, then the per-object encryption key is derived from this random key in the following way:
For compatibility with SFTPGo versions 1.2.x and before we also support encryption based on AES-256-GCM
. The data encrypted with this algorithm will never use the master key to keep backward compatibility. You can activate it using builtin://
as url
but this is not recommended.
Several cloud providers are supported using the sftpgo-plugin-kms.