This commit improves the listing of encrypted objects:
- Use `etag.Format` and `etag.Decrypt`
- Detect SSE-S3 single-part objects in a single iteration
- Fix batch size to `250`
- Pass request context to `DecryptAll` to not waste resources
when a client cancels the operation.
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
This commit adds two new functions to the
internal `etag` package:
- `ETag.Format`
- `Decrypt`
The `Decrypt` function decrypts an encrypted
ETag using a decryption key. It returns not
encrypted / multipart ETags unmodified.
The `Decrypt` function is mainly used when
handling SSE-S3 encrypted single-part objects.
In particular, the ETag of an SSE-S3 encrypted
single-part object needs to be decrypted since
S3 clients expect that this ETag is equal to the
content MD5.
The `ETag.Format` method also covers SSE ETag handling.
MinIO encrypts all ETags of SSE single part objects.
However, only the ETag of SSE-S3 encrypted single part
objects needs to be decrypted.
The ETag of an SSE-C or SSE-KMS single part object
does not correspond to its content MD5 and can be
a random value.
The `ETag.Format` function formats an ETag such that
it is an AWS S3 compliant ETag. In particular, it
returns non-encrypted ETags (single / multipart)
unmodified. However, for encrypted ETags it returns
the trailing 16 bytes as ETag. For encrypted ETags
the last 16 bytes will be a random value.
The main purpose of `Format` is to format ETags
such that clients accept them as well-formed AWS S3
ETags.
It differs from the `String` method since `String`
will return string representations for encrypted
ETags that are not AWS S3 compliant.
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
The deployment id was being written to the health report towards the end
of the handler. Because of this, if there was a timeout in any of the
data fetching, the deployment id was not getting written at all. Upload
of such reports fails on SUBNET as deployment id is the unique
identifier for a cluster in subnet.
Fixed by writing the deployment id at the beginning of the processing.
This commit simplifies the ETag decryption and size adjustment
when listing object parts.
When listing object parts, MinIO has to decrypt the ETag of all
parts if and only if the object resp. the parts is encrypted using
SSE-S3.
In case of SSE-KMS and SSE-C, MinIO returns a pseudo-random ETag.
This is inline with AWS S3 behavior.
Further, MinIO has to adjust the size of all encrypted parts due to
the encryption overhead.
The ListObjectParts does specifically not use the KMS bulk decryption
API (4d2fc530d0) since the ETags of all
parts are encrypted using the same object encryption key. Therefore,
MinIO only has to connect to the KMS once, even if there are multiple
parts resp. ETags. It can simply reuse the same object encryption key.
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
This commit adds support for encrypted KES
client private keys.
Now, it is possible to encrypt the KES client
private key (`MINIO_KMS_KES_KEY_FILE`) with
a password.
For example, KES CLI already supports the
creation of encrypted private keys:
```
kes identity new --encrypt --key client.key --cert client.crt MinIO
```
To decrypt an encrypted private key, the password
needs to be provided:
```
MINIO_KMS_KES_KEY_PASSWORD=<password>
```
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
This commit optimises the ETag decryption when
listing objects.
When MinIO lists objects, it has to decrypt the
ETags of single-part SSE-S3 objects.
It does not need to decrypt ETags of
- plaintext objects => Their ETag is not encrypted
- SSE-C objects => Their ETag is not the content MD5
- SSE-KMS objects => Their ETag is not the content MD5
- multipart objects => Their ETag is not encrypted
Hence, MinIO only needs to make a call to the KMS
when it needs to decrypt a single-part SSE-S3 object.
It can resolve the ETags off all other object types
locally.
This commit implements the above semantics by
processing an object listing in batches.
If the batch contains no single-part SSE-S3 object,
then no KMS calls will be made.
If the batch contains at least one single-part
SSE-S3 object we have to make at least one KMS call.
No we first filter all single-part SSE-S3 objects
such that we only request the decryption keys for
these objects.
Once we know which objects resp. ETags require a
decryption key, MinIO either uses the KES bulk
decryption API (if supported) or decrypts each
ETag serially.
This commit is a significant improvement compared
to the previous listing code. Before, a single
non-SSE-S3 object caused MinIO to fall-back to
a serial ETag decryption.
For example, if a batch consisted of 249 SSE-S3
objects and one single SSE-KMS object, MinIO would
send 249 requests to the KMS.
Now, MinIO will send a single request for exactly
those 249 objects and skip the one SSE-KMS object
since it can handle its ETag locally.
Further, MinIO would request decryption keys
for SSE-S3 multipart objects in the past - even
though multipart ETags are not encrypted.
So, if a bucket contained only multipart SSE-S3
objects, MinIO would make totally unnecessary
requests to the KMS.
Now, MinIO simply skips these multipart objects
since it can handle the ETags locally.
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
In bulk ETag decryption, do not rely on the etag to check if it is
encrypted or not to decide if we should set the actual object size in
ObjectInfo. The reason is that multipart objects ETags are not
encrypted.
Always get the actual object size in that case.
This commit fixes a subtle bug in the ETag
`IsEncrypted` implementation.
An encrypted ETag may contain random bytes,
i.e. some randomness used for encryption.
This random value can contain a '-' byte
simple due to being randomly generated.
Before, the `IsEncrypted` implementation
incorrectly assumed that an encrypted ETag
cannot contain a '-' since it would be a
multipart ETag. Multipart ETags have a
16 byte value followed by a '-' and the part number.
For example:
```
059ba80b807c3c776fb3bcf3f33e11ae-2
```
However, the following encrypted ETag
```
20000f00db2d90a7b40782d4cff2b41a7799fc1e7ead25972db65150118dfbe2ba76a3c002da28f85c840cd2001a28a9
```
also contains a '-' byte but is not a multipart ETag.
This commit fixes the `IsEncrypted` implementation
simply by checking whether the ETag is at least 32
bytes long. A valid multipart ETag is never 32 bytes
long since a part number must be <= 10000.
However, an encrypted ETag must be at least 32 bytes
long. It contains the encrypted ETag bytes (16 bytes)
and the authentication tag added by the AEAD cipher (again
16 bytes).
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
This commit adds support for bulk ETag
decryption for SSE-S3 encrypted objects.
If KES supports a bulk decryption API, then
MinIO will check whether its policy grants
access to this API. If so, MinIO will use
a bulk API call instead of sending encrypted
ETags serially to KES.
Note that MinIO will not use the KES bulk API
if its client certificate is an admin identity.
MinIO will process object listings in batches.
A batch has a configurable size that can be set
via `MINIO_KMS_KES_BULK_API_BATCH_SIZE=N`.
It defaults to `500`.
This env. variable is experimental and may be
renamed / removed in the future.
Signed-off-by: Andreas Auernhammer <hi@aead.dev>
