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 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 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.
