func Decrypt(k kms.KMS, ciphertext io.Reader, context kms.Context) (io.Reader, error) {
	const (
		MaxMetadataSize = 1 << 20 // max. size of the metadata
		Version         = 1
	)

	var header [5]byte
	if _, err := io.ReadFull(ciphertext, header[:]); err != nil {
		return nil, err
	}
	if header[0] != Version {
		return nil, fmt.Errorf("config: unknown ciphertext version %d", header[0])
	}

	return
}

// EncryptSinglePart encrypts an io.Reader which must be the
// body of a single-part PUT request.
func EncryptSinglePart(r io.Reader, key ObjectKey) io.Reader {
	r, err := sio.EncryptReader(r, sio.Config{MinVersion: sio.Version20, Key: key[:], CipherSuites: fips.DARECiphers()})
	if err != nil {
		logger.CriticalIf(context.Background(), errors.New("Unable to encrypt io.Reader using object key"))
	}
	return r
}

)

var magicHeaders = []struct {
	header []byte
	f      format
}{
	{
		header: []byte{0x1f, 0x8b, 8},
		f:      formatGzip,
	},
	{
		// Zstd default header.
		header: []byte{0x28, 0xb5, 0x2f, 0xfd},
		f:      formatZstd,
	},
	{
		// Zstd skippable frame header.
		header: []byte{0x2a, 0x4d, 0x18},
		f:      formatZstd,
	},
	{
		// LZ4
		header: []byte{0x4, 0x22, 0x4d, 0x18},

from pydantic import BaseModel

app = FastAPI()

api_key = APIKeyHeader(name="key", description="An API Key Header")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: User = Depends(get_current_user)):

Jendrik Johannes <******@****.***> 1607501645 +0100

Shinsuke Sugaya <******@****.***> 1638450896 +0900

app = FastAPI()

api_key = APIKeyHeader(name="key", auto_error=False)


class User(BaseModel):
    username: str


def get_current_user(oauth_header: Optional[str] = Security(api_key)):
    if oauth_header is None:
        return None
    user = User(username=oauth_header)
    return user


@app.get("/users/me")
def read_current_user(current_user: Optional[User] = Depends(get_current_user)):
    if current_user is None:

        return api_key


class APIKeyHeader(APIKeyBase):
    """
    API key authentication using a header.

    This defines the name of the header that should be provided in the request with
    the API key and integrates that into the OpenAPI documentation. It extracts
    the key value sent in the header automatically and provides it as the dependency
    result. But it doesn't define how to send that key to the client.

#include <vector>

#include "tensorflow/c/eager/abstract_context.h"
#include "tensorflow/c/eager/abstract_tensor_handle.h"
#include "tensorflow/c/eager/c_api.h"
#include "tensorflow/c/eager/c_api_unified_experimental.h"
#include "tensorflow/c/eager/c_api_unified_experimental_internal.h"
#include "tensorflow/c/eager/immediate_execution_context.h"
#include "tensorflow/c/eager/immediate_execution_tensor_handle.h"

 */
internal interface DerAdapter<T> {
  /** Returns true if this adapter can read [header] in a choice. */
  fun matches(header: DerHeader): Boolean

  /**
   * Returns a value from this adapter.
   *
   * This must always return a value, though it doesn't necessarily need to consume data from
   * [reader]. For example, if the reader's peeked tag isn't readable by this adapter, it may return
   * a default value.
   *