move cloud KMS providers to an external plugin

This commit is contained in:
Nicola Murino
2021-07-17 13:08:05 +02:00
parent 6d313f6d8f
commit 338301955f
11 changed files with 5 additions and 380 deletions

View File

@@ -9,8 +9,6 @@ The `secrets` section of the `kms` configuration allows to configure how to encr
- `url` defines the URI to the KMS service
- `master_key_path` defines the absolute path to a file containing the master encryption key. This could be, for example, a docker secrets or a file protected with filesystem level permissions.
We use [Go CDK](https://gocloud.dev/howto/secrets/) to access several key management services in a portable way.
### Local provider
If the `url` is empty SFTPGo uses local encryption for keeping secrets. Internally, it uses the [NaCl secret box](https://pkg.go.dev/golang.org/x/crypto/nacl/secretbox) algorithm to perform encryption and authentication.
@@ -22,41 +20,9 @@ We first generate a random key, then the per-object encryption key is derived fr
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.
### Google Cloud Key Management Service
### Cloud providers
To use keys from Google Cloud Platforms [Key Management Service](https://cloud.google.com/kms/) (GCP KMS) you have to use `gcpkms` as URL scheme like this:
```shell
gcpkms://projects/[PROJECT_ID]/locations/[LOCATION]/keyRings/[KEY_RING]/cryptoKeys/[KEY]
```
SFTPGo will use Application Default Credentials. See [here](https://cloud.google.com/docs/authentication/production) for alternatives such as environment variables.
The URL host+path are used as the key resource ID; see [here](https://cloud.google.com/kms/docs/object-hierarchy#key) for more details.
If a master key is provided we first encrypt the plaintext data using the local provider and then we encrypt the resulting payload using the Cloud provider and store this ciphertext.
### AWS Key Management Service
To use customer master keys from Amazon Web Services [Key Management Service](https://aws.amazon.com/kms/) (AWS KMS) you have to use `awskms` as URL scheme. You can use the keys ID, alias, or Amazon Resource Name (ARN) to identify the key. You should specify the region query parameter to ensure your application connects to the correct region.
Here are some examples:
- By ID: `awskms://1234abcd-12ab-34cd-56ef-1234567890ab?region=us-east-1`
- By alias: `awskms://alias/ExampleAlias?region=us-east-1`
- By ARN: `arn:aws:kms:us-east-1:111122223333:key/1234abcd-12ab-34bc-56ef-1234567890ab?region=us-east-1`
SFTPGo will use the default AWS session. See [AWS Session](https://docs.aws.amazon.com/sdk-for-go/api/aws/session/) to learn about authentication alternatives such as environment variables.
If a master key is provided we first encrypt the plaintext data using the local provider and then we encrypt the resulting payload using the Cloud provider and store this ciphertext.
### HashiCorp Vault
To use the [transit secrets engine](https://www.vaultproject.io/docs/secrets/transit/index.html) in [Vault](https://www.vaultproject.io/) you have to use `hashivault` as URL scheme like this: `hashivault://mykey`.
The Vault server endpoint and authentication token are specified using the environment variables `VAULT_SERVER_URL` and `VAULT_SERVER_TOKEN`, respectively.
If a master key is provided we first encrypt the plaintext data using the local provider and then we encrypt the resulting payload using Vault and store this ciphertext.
Several cloud providers are supported using the [sftpgo-plugin-kms](https://github.com/sftpgo/sftpgo-plugin-kms).
### Notes