This commit adds two functions for sealing/unsealing the
etag (a.k.a. content MD5) in case of SSE single-part upload.
Sealing the ETag is neccessary in case of SSE-S3 to preserve
the security guarantees. In case of SSE-S3 AWS returns the
content-MD5 of the plaintext object as ETag. However, we
must not store the MD5 of the plaintext for encrypted objects.
Otherwise it becomes possible for an attacker to detect
equal/non-equal encrypted objects. Therefore we encrypt
the ETag before storing on the backend. But we only need
to encrypt the ETag (content-MD5) if the client send it -
otherwise the client cannot verify it anyway.
This commit adds two functions for removing
confidential information - like SSE-C keys -
from HTTP headers / object metadata.
This creates a central point grouping all
headers/entries which must be filtered / removed.
See also https://github.com/minio/minio/pull/6489#discussion_r219797993
of #6489
This commit fixes are regression in the server regarding
handling SSE requests with wrong SSE-C keys.
The server now returns an AWS S3 compatable API error (access denied)
in case of the SSE key does not match the secret key used during upload.
Fixes#6431
Add support for sse-s3 encryption with vault as KMS.
Also refactoring code to make use of headers and functions defined in
crypto package and clean up duplicated code.
This commit adds support for detecting SSE-KMS headers.
The server should be able to detect SSE-KMS headers to
at least fail such S3 requests with not implemented.
This commit adds a `fmt.Stringer` implementation for
SSE-S3 and SSE-C. The string representation is the
domain used for object key sealing.
See: `ObjectKey.Seal(...)` and `ObjectKey.Unseal(...)`
* crypto: add support for parsing SSE-C/SSE-S3 metadata
This commit adds support for detecting and parsing
SSE-C/SSE-S3 object metadata. With the `IsEncrypted`
functions it is possible to determine whether an object
seems to be encrypted. With the `ParseMetadata` functions
it is possible to validate such metadata and extract the
SSE-C/SSE-S3 related values.
It also fixes some naming issues.
* crypto: add functions for creating SSE object metadata
This commit adds functions for creating SSE-S3 and
SSE-C metadata. It also adds a `CreateMultipartMetadata`
for creating multipart metadata.
For all functions unit tests are included.
This commit adds basic support for SSE-C / SSE-C copy.
This includes functions for determining whether SSE-C
is requested by the S3 client and functions for parsing
such HTTP headers.
All S3 SSE-C parsing errors are exported such that callers
can pattern-match to forward the correct error to S3
clients.
Further the SSE-C related internal metadata entry-keys
are added by this commit.
This commit adds a basic KMS implementation for an
operator-specified SSE-S3 master key. The master key
is wrapped as KMS such that using SSE-S3 with master key
and SSE-S3 with KMS can use the same code.
Bindings for a remote / true KMS (like hashicorp vault)
will be added later on.
This commit updates the key derivation to reflect the
latest change of crypto/doc.go. This includes handling
the insecure legacy KDF.
Since #6064 is fixed, the 3. test case for object key
generation is enabled again.
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 commit introduces a new crypto package providing
AWS S3 related cryptographic building blocks to implement
SSE-S3 (master key or KMS) and SSE-C.
This change only adds some basic functionallity esp.
related to SSE-S3 and documents the general approach
for SSE-S3 and SSE-C.
