//     -   ObjectKey := DAREv2_Dec(KeyEncKey, SealedKey)
//     - object_data := DAREv2_Dec(ObjectKey, enc_object_data)
//     Output: object_data
//
// ### SSE-S3 and KMS
//
// SSE-S3 requires that the KMS provides two functions:
//
//  1. Generate(KeyID) -> (Key, EncKey)
//
//  2. Unseal(KeyID, EncKey) -> Key
//
//  1. Encrypt:
//     Input: KeyID, bucket, object, metadata, object_data

present to create such a binary.

Most builds both compile source code and invoke the linker to create a
binary. When cgo is involved, the compile step already requires gcc, so
it is not problematic for the link step to require gcc too.

An important exception is builds using a pre-compiled copy of the
standard library. In particular, package net uses cgo on most systems,

// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.