This PR sets the default AESCrypt stream format to v2.
This is done to introduce the ability to read the v3 format before switching to the new format. With a delayed activation, it is more likely that users can easily roll back a version if needed.
This PR updates SharpAESCrypt to version 3.0.0.
With this change the written format for encrypted fields in the database and the remote encrypted files will be changed to Stream Format v3, which improves the key deriviation function and includes additional safeguards regarding content length.
The library still supports reading v2 files, but will write all new files as v3.
Environment variables, as well as module options, can toggle this behavior.
# Environment variable overview
- `DUPLICATI__AES_VERSION`: The file format version, either 3 (default) or 2
-`DUPLICATI__AES_V3_ITERATIONS`: The number of Pbkdf iterations to apply (default 300k)
- `DUPLICATI__AES_MINIMAL_HEADER`: Writes AES files with a minimal header (saves ~100 bytes per file)
- `DUPLICATI__AES_IGNORE_PADDING_BYTES`: Legacy setting for reading files written by the mainline AESCrypt tool
# A note on iterations
The iterations protect a weak key by adding additional computational overhead, but only adds overhead if the key is already providing at least 256 bits of high entropy.
For low-power devices, such as 32-bit RPI, this can be set as low as 10k, which will lower encryption and decryption time. Beware that setting a low iteration count reduces security if the key is not sufficiently strong.
This PR adds masking to remote sources so the passwords are not leaked to the browser. The logic works the same as for TargetURL, where the sensitive fields are replaced by a password placeholder before being transmitted via the endpoints.
When data returns, the masking is removed by looking at the original source and the unmasked value is then encrypted before being stored in the database.
Since the sources is an array and not just a single field, the logic here uses the mount point as a "key" for figuring out which new sources map to the original sources. This is robust in the face of re-ordering, deletions and additions.
If there is just a single remote source (assumed most common) this will match even if the prefix does not, making it possible to change the prefix in this case.
For multi-remote sources, it is not possible to change the prefix without also re-typing all masked properties.
If there is a need later, we could extend the matching to look for how many unique protocols are there, and maybe servers as well to try to match better when the prefixes have been renamed.
There is a guard right before saving a source that rejects it if the source contains the placeholder so we ensure that even faulty logic cannot persist an invalid connection string.
Kept the infrastructure to allow re-introducing it later if a better source for a device key is found.
Added support for not having any valid settings encryption key.
Added warnings if the user is running without a settings encryption key.
Added additional checks during startup to help with troubleshooting and configuring a setup with a settings encryption key.
Docker builds will now warn if no encryption key is set.
This fixes#5518
This updates all projects to target .NET Framework 4.7.1. The
TencentCOS and Tardigrade backends depend on .NET Standard 2.0. When a
.NET Framework prior to 4.7.1 is targeted, the system cannot be sure
that all the dependencies exist, so it copies all dependent assemblies
to the output directory. This causes many assemblies from the System
namespace to become bundled in the release.
https://stackoverflow.com/a/48875007
We had previously attempted to make individual projects target 4.7.1
(see pull request #4242), but this can cause compatibility issues when
4.6.2 projects depend on 4.7.1. projects.
This will require Mono 5.10.0 or greater (previously, we required 5.0.0
or greater).
https://www.mono-project.com/docs/about-mono/releases/5.10.0/#class-libraries
This fixes issue #4234.
Kenneth Skovhede