return psv, ErrInvalidQuerySignatureAlgo
	}

	// Initialize signature version '4' structured header.
	preSignV4Values := preSignValues{}

	// Save credential.
	preSignV4Values.Credential, aec = parseCredentialHeader("Credential="+query.Get(xhttp.AmzCredential), region, stype)
	if aec != ErrNone {
		return psv, aec
	}

	var e error
	// Save date in native time.Time.

	}{
		{"shastring", "", "shastring"},
		{emptySHA256, "", emptySHA256},
		{"", "", emptySHA256},
		{"", "X-Amz-Credential=random", unsignedPayload},
		{"", "X-Amz-Credential=random&X-Amz-Content-Sha256=" + unsignedPayload, unsignedPayload},
		{"", "X-Amz-Credential=random&X-Amz-Content-Sha256=shastring", "shastring"},
	}

	for i, testCase := range testCases {

    responses += response
    routes += route
    if (!schemeMatches(response) || credential == null) return null
    val header =
      when (response.code) {
        407 -> "Proxy-Authorization"
        else -> "Authorization"
      }
    return response.request.newBuilder()
      .addHeader(header, credential)
      .build()
  }

  private fun schemeMatches(response: Response): Boolean {

	// Add the date condition, only accept the current date.
	dateConditionStr := fmt.Sprintf(`["eq", "$x-amz-date", "%s"]`, t.Format(iso8601DateFormat))
	// Add the credential string, only accept the credential passed.
	credentialConditionStr := fmt.Sprintf(`["eq", "$x-amz-credential", "%s"]`, credential)
	// Add the meta-uuid string, set to 1234
	uuidConditionStr := fmt.Sprintf(`["eq", "$x-amz-meta-uuid", "%s"]`, "1234")

	}
}

// TestParseCredentialHeader - validates the format validator and extractor for the Credential header in an aws v4 request.
// A valid format of credential should be of the following format.
// Credential = accessKey + SlashSeparator+ scope
// where scope = string.Join([]string{  currTime.Format(yyyymmdd),
//
//				globalMinioDefaultRegion,
//	              	"s3",

        Set<Object> serverPrivateCredentials = this.subject.getPrivateCredentials();
        for ( Object credential : serverPrivateCredentials )
            if ( credential instanceof KerberosKey )
                if ( ( (KerberosKey) credential ).getKeyType() == keyType )
                    serverKey = (KerberosKey) credential;

        return serverKey;
    }


    public Subject getSubject () {
        return this.subject;

            this.resolver = resolver;
        }

        public <CREDENTIAL extends LoginCredential> void resolve(final Class<CREDENTIAL> credentialType,
                final Function<CREDENTIAL, OptionalEntity<FessUser>> oneArgLambda) {
            resolver.resolve(credentialType, credential -> oneArgLambda.apply(credential));
        }
    }

	// Get string to sign from canonical request.
	presignedStringToSign := getStringToSign(presignedCanonicalReq, t, pSignValues.Credential.getScope())

	// Get hmac presigned signing key.
	presignedSigningKey := getSigningKey(cred.SecretKey, pSignValues.Credential.scope.date,
		pSignValues.Credential.scope.region, stype)

	// Get new signature.
	newSignature := getSignature(presignedSigningKey, presignedStringToSign)

	testCases := []struct {
		form     http.Header
		expected APIErrorCode
	}{
		// (0) It should fail if 'X-Amz-Credential' is missing.
		{
			form:     http.Header{},
			expected: ErrCredMalformed,
		},
		// (1) It should fail if the access key is incorrect.
		{
			form: http.Header{
				"X-Amz-Credential": []string{fmt.Sprintf(credentialTemplate, "EXAMPLEINVALIDEXAMPL", now.Format(yyyymmdd), globalMinioDefaultRegion)},
			},

        val credentialHeader = if (proxyAuthorization) "Proxy-Authorization" else "Authorization"
        val credential =
          Credentials.basic(
            auth.userName,
            String(auth.password),
            challenge.charset,
          )
        return request.newBuilder()
          .header(credentialHeader, credential)
          .build()
      }
    }

    return null // No challenges were satisfied!
  }