This commit fixes the size calculation for multipart
objects. The decrypted size of an encrypted multipart
object is the sum of the decrypted part sizes.
Also fixes the key derivation in CopyObjectPart.
Instead of using the same object-encryption-key for each
part now an unique per-part key is derived.
Updates #6139
This commit fixes a weakness of the key-encryption-key
derivation for SSE-C encrypted objects. Before this
change the key-encryption-key was not bound to / didn't
depend on the object path. This allows an attacker to
repalce objects - encrypted with the same
client-key - with each other.
This change fixes this issue by updating the
key-encryption-key derivation to include:
- the domain (in this case SSE-C)
- a canonical object path representation
- the encryption & key derivation algorithm
Changing the object path now causes the KDF to derive a
different key-encryption-key such that the object-key
unsealing fails.
Including the domain (SSE-C) and encryption & key
derivation algorithm is not directly neccessary for this
fix. However, both will be included for the SSE-S3 KDF.
So they are included here to avoid updating the KDF
again when we add SSE-S3.
The leagcy KDF 'DARE-SHA256' is only used for existing
objects and never for new objects / key rotation.
This is an effort to remove panic from the source.
Add a new call called CriticialIf, that calls LogIf and exits.
Replace panics with one of CriticalIf, FatalIf and a return of error.
This change let the server return the S3 error for a key rotation
if the source key is not valid but equal to the destination key.
This change also fixes the SSE-C error messages since AWS returns error messages
ending with a '.'.
Fixes#5625
Current code didn't implement the logic to support
decrypting encrypted multiple parts, this PR fixes
by supporting copying encrypted multipart objects.
*) Add Put/Get support of multipart in encryption
*) Add GET Range support for encryption
*) Add CopyPart encrypted support
*) Support decrypting of large single PUT object
This PR changes the behavior of DecryptRequest.
Instead of returning `object-tampered` if the client provided
key is wrong DecryptRequest will return `access-denied`.
This is AWS S3 behavior.
Fixes#5202
This chnage replaces the current SSE-C key derivation scheme. The 'old'
scheme derives an unique object encryption key from the client provided key.
This key derivation was not invertible. That means that a client cannot change
its key without changing the object encryption key.
AWS S3 allows users to update there SSE-C keys by executing a SSE-C COPY with
source == destination. AWS probably updates just the metadata (which is a very
cheap operation). The old key derivation scheme would require a complete copy
of the object because the minio server would not be able to derive the same
object encryption key from a different client provided key (without breaking
the crypto. hash function).
This change makes the key derivation invertible.
This change adds server-side-encryption support for HEAD, GET and PUT
operations. This PR only addresses single-part PUTs and GETs without
HTTP ranges.
Further this change adds the concept of reserved object metadata which is required
to make encrypted objects tamper-proof and provide API compatibility to AWS S3.
This PR adds the following reserved metadata entries:
- X-Minio-Internal-Server-Side-Encryption-Iv ('guarantees' tamper-proof property)
- X-Minio-Internal-Server-Side-Encryption-Kdf (makes Key-MAC computation negotiable in future)
- X-Minio-Internal-Server-Side-Encryption-Key-Mac (provides AWS S3 API compatibility)
The prefix `X-Minio_Internal` specifies an internal metadata entry which must not
send to clients. All client requests containing a metadata key starting with `X-Minio-Internal`
must also rejected. This is implemented by a generic-handler.
This PR implements SSE-C separated from client-side-encryption (CSE). This cannot decrypt
server-side-encrypted objects on the client-side. However, clients can encrypted the same object
with CSE and SSE-C.
This PR does not address:
- SSE-C Copy and Copy part
- SSE-C GET with HTTP ranges
- SSE-C multipart PUT
- SSE-C Gateway
Each point must be addressed in a separate PR.
Added to vendor dir:
- x/crypto/chacha20poly1305
- x/crypto/poly1305
- github.com/minio/sio
Andreas Auernhammer