code: def hmac_signature(string, shared_secret, challenge_hmac):
      '''
      Verify a challenging hmac signature against a string / shared-secret
  
      .. versionadded:: 2014.7.0
  
      Returns a boolean if the verification succeeded or failed.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' hashutil.hmac_signature 'get salted' 'shared secret' 'eBWf9bstXg+NiP5AOwppB5HMvZiYMPzEM9W5YMm/AmQ='
      '''
      return salt.utils.hashutils.hmac_signature(string, shared_secret, challenge_hmacf hmac_signature(string, shared_secret, challenge_hmac):
      '''
      Verify a challenging hmac signature against a string / shared-secret
  
      .. versionadded:: 2014.7.0
  
      Returns a boolean if the verification succeeded or failed.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' hashutil.hmac_signature 'get salted' 'shared secret' 'eBWf9bstXg+NiP5AOwppB5HMvZiYMPzEM9W5YMm/AmQ='
      '''
      return salt.utils.hashutils.hmac_signature(string, shared_secret, challenge_hmac)
docs: Verify a challenging hmac signature against a string / shared-secret
  
      .. versionadded:: 2014.7.0
  
      Returns a boolean if the verification succeeded or failed.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' hashutil.hmac_signature 'get salted' 'shared secret' 'eBWf9bstXg+NiP5AOwppB5HMvZiYMPzEM9W5YMm/AmQ='