Add SSE-C key configuration option for Amazon S3 remote backups

changelogs/unreleased/backup_aws_sse-c.yml

+title: Add support for customer provided encryption keys for Amazon S3 remote backups
+merge_request: 23797
+author: Pepijn Van Eeckhoudt
+type: added
+

config/gitlab.yml.example

@@ -635,6 +635,10 @@ production: &base
     #   multipart_chunk_size: 104857600
     #   # Turns on AWS Server-Side Encryption with Amazon S3-Managed Keys for backups, this is optional
     #   # encryption: 'AES256'
+    #   # Turns on AWS Server-Side Encryption with Amazon Customer-Provided Encryption Keys for backups, this is optional
+    #   #   This should be set to the 256-bit, base64-encoded encryption key for Amazon S3 to use to encrypt or decrypt your data. 
+    #   #   'encryption' must also be set in order for this to have any effect. 
+    #   # encryption_key: '<base64 key>'
     #   # Specifies Amazon S3 storage class to use for backups, this is optional
     #   # storage_class: 'STANDARD'

config/initializers/1_settings.rb

@@ -392,6 +392,7 @@ Settings.backup['archive_permissions'] ||= 0600
 Settings.backup['upload'] ||= Settingslogic.new({ 'remote_directory' => nil, 'connection' => nil })
 Settings.backup['upload']['multipart_chunk_size'] ||= 104857600
 Settings.backup['upload']['encryption'] ||= nil
+Settings.backup['upload']['encryption_key'] ||= ENV['GITLAB_BACKUP_ENCRYPTION_KEY']
 Settings.backup['upload']['storage_class'] ||= nil
 #

doc/raketasks/backup_restore.md

@@ -311,6 +311,11 @@ For installations from source:
           remote_directory: 'my.s3.bucket'
           # Turns on AWS Server-Side Encryption with Amazon S3-Managed Keys for backups, this is optional
           # encryption: 'AES256'
+          # Turns on AWS Server-Side Encryption with Amazon Customer-Provided Encryption Keys for backups, this is optional
+          #   This should be set to the base64-encoded encryption key for Amazon S3 to use to encrypt or decrypt your data.
+          #   'encryption' must also be set in order for this to have any effect.
+          #   To avoid storing the key on disk, the key can also be specified via the `GITLAB_BACKUP_ENCRYPTION_KEY` environment variable.
+          # encryption_key: '<base64 key>'
           # Specifies Amazon S3 storage class to use for backups, this is optional
           # storage_class: 'STANDARD'
     ```

lib/backup/manager.rb

@@ -50,6 +50,7 @@ module Backup
       if directory.files.create(key: remote_target, body: File.open(tar_file), public: false,
                                 multipart_chunk_size: Gitlab.config.backup.upload.multipart_chunk_size,
                                 encryption: Gitlab.config.backup.upload.encryption,
+                                encryption_key: Gitlab.config.backup.upload.encryption_key,
                                 storage_class: Gitlab.config.backup.upload.storage_class)
         progress.puts "done".color(:green)
       else

spec/lib/backup/manager_spec.rb

@@ -266,6 +266,7 @@ describe Backup::Manager do
           remote_directory: 'directory',
           multipart_chunk_size: 104857600,
           encryption: nil,
+          encryption_key: nil,
           storage_class: nil
         }
       )