{* ../../docs_src/security/tutorial007_an_py310.py hl[1,12:24] *}

这类似于：

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Return some error
    ...
```

但使用 `secrets.compare_digest()`，可以防御**时差攻击**，更加安全。

### 时差攻击 { #timing-attacks }

什么是**时差攻击**？

假设攻击者试图猜出用户名与密码。

他们发送用户名为 `johndoe`，密码为 `love123` 的请求。

然后，Python 代码执行如下操作：

// span the local and remote workers. If the graph optimization pass is executed
// on both the main function side and the component function side, an error will
// be thrown in the registered graph optimization pass.
TEST(CAPI, DistributedFunctionGraphPassOnlyOnce) {
  // Register graph pass that will raise error if called more than once.
  tensorflow::optimization_registration::OptimizationPassRegistration

        when(locator.getURL()).thenReturn(createSmbURL("smb://"));
        when(nameFilter.accept(any(SmbResource.class), anyString())).thenThrow(new CIFSException("Filter error"));

        // Mock response
        when(treeHandle.send(any(), any(), (RequestParam[]) any())).thenAnswer(invocation -> {
            return invocation.getArgument(1);
        });

   * {@code void}, {@code null} is returned.
   */
  @SuppressWarnings({
    "unchecked",
    "BooleanLiteral" // `(T) false` would produce an error
  })
  public static <T> @Nullable T defaultValue(Class<T> type) {
    checkNotNull(type);
    if (type.isPrimitive()) {
      if (type == boolean.class) {
        return (T) Boolean.FALSE;

    }

    /**
     * Returns the security descriptor of the share as an array of ACEs.
     *
     * @return an array of ACE objects representing the share's security descriptor
     * @throws IOException if there is an error retrieving the security information
     */
    public ACE[] getSecurity() throws IOException {
        final srvsvc.ShareInfo502 info502 = (srvsvc.ShareInfo502) this.info;
        if (info502.security_descriptor != null) {

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.artifact.repository.metadata;

/**
 * Error while installing repository metadata.
 *
 */
@Deprecated
public class RepositoryMetadataInstallationException extends Throwable {
    public RepositoryMetadataInstallationException(String message) {
        super(message);

                "flags should be DCERPC_FIRST_FRAG | DCERPC_LAST_FRAG");
        // Verify that the super constructor was called with the correct handle.
        // This is implicitly tested by the object being created without error and
        // the fields set by the constructor being correct.
    }

// The entry not chosen will be discarded.
// If the context is canceled the function will return the error,
// otherwise the function will return nil.
func mergeEntryChannels(ctx context.Context, in []chan metaCacheEntry, out chan<- metaCacheEntry, readQuorum int) error {
	defer xioutil.SafeClose(out)
	top := make([]*metaCacheEntry, len(in))
	nDone := 0
	ctxDone := ctx.Done()

	exit 1
fi

## Check replication of deleted ILM expiry rules
./mc ilm rule remove --id "${id}" sitea/bucket
sleep 30s

# should error as rule doesn't exist
error=$(./mc ilm rule list siteb/bucket --json | jq '.error.cause.message' | sed 's/"//g')
if [ "$error" != "The lifecycle configuration does not exist" ]; then
	echo "BUG: Removed ILM expiry rule not replicated to 'siteb'"
	exit 1
fi

EnvironmentFile=-${packaging.env.file}

User=${packaging.fess.user}
Group=${packaging.fess.group}

ExecStart=${packaging.fess.bin.dir}/fess

# Connects standard output to /dev/null
StandardOutput=null

# Connects standard error to journal
StandardError=journal

# When a JVM receives a SIGTERM signal it exits with code 143
SuccessExitStatus=143

# Specifies the maximum file descriptor number that can be opened by this process