This commit changes how MinIO generates the object encryption key (OEK)
when encrypting an object using server-side encryption.
This change is fully backwards compatible. Now, MinIO generates
the OEK as following:
```
Nonce = RANDOM(32) // generate 256 bit random value
OEK = HMAC-SHA256(EK, Context || Nonce)
```
Before, the OEK was computed as following:
```
Nonce = RANDOM(32) // generate 256 bit random value
OEK = SHA256(EK || Nonce)
```
The new scheme does not technically fix a security issue but
uses a more familiar scheme. The only requirement for the
OEK generation function is that it produces a (pseudo)random value
for every pair (`EK`,`Nonce`) as long as no `EK`-`Nonce` combination
is repeated. This prevents a faulty PRNG from repeating or generating
a "bad" key.
The previous scheme guarantees that the `OEK` is a (pseudo)random
value given that no pair (`EK`,`Nonce`) repeats under the assumption
that SHA256 is indistinguable from a random oracle.
The new scheme guarantees that the `OEK` is a (pseudo)random value
given that no pair (`EK`, `Nonce`) repeats under the assumption that
SHA256's underlying compression function is a PRF/PRP.
While the later is a weaker assumption, and therefore, less likely
to be false, both are considered true. SHA256 is believed to be
indistinguable from a random oracle AND its compression function
is assumed to be a PRF/PRP.
As far as the OEK generating is concerned, the OS random number
generator is not required to be pseudo-random but just non-repeating.
Apart from being more compatible to standard definitions and
descriptions for how to generate crypto. keys, this change does not
have any impact of the actual security of the OEK key generation.
Signed-off-by: Andreas Auernhammer <github@aead.dev>
A lot of warning messages are printed in CI/CD failures generated by go
test. Avoid that by requiring at least Error level for logging when
doing go test.
Add up to 256 bytes of padding for compressed+encrypted files.
This will obscure the obvious cases of extremely compressible content
and leave a similar output size for a very wide variety of inputs.
This does *not* mean the compression ratio doesn't leak information
about the content, but the outcome space is much smaller,
so often *less* information is leaked.
It would seem like the PR #11623 had chewed more
than it wanted to, non-fips build shouldn't really
be forced to use slower crypto/sha256 even for
presumed "non-performance" codepaths. In MinIO
there are really no "non-performance" codepaths.
This assumption seems to have had an adverse
effect in certain areas of CPU usage.
This PR ensures that we stick to sha256-simd
on all non-FIPS builds, our most common build
to ensure we get the best out of the CPU at
any given point in time.
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 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>
- remove some duplicated code
- reported a bug, separately fixed in #13664
- using strings.ReplaceAll() when needed
- using filepath.ToSlash() use when needed
- remove all non-Go style comments from the codebase
Co-authored-by: Aditya Manthramurthy <donatello@users.noreply.github.com>
json.Unmarshal expects a pointer receiver, otherwise
kms.Context unmarshal fails with lack of pointer receiver,
this becomes complicated due to type aliasing over
map[string]string - fix it properly.
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`
Andreas Auernhammer
Harshavardhana
Anis Eleuch
Aditya Manthramurthy
ferhat elmas
Abirdcfly
Klaus Post
Andreas Auernhammer