code: def verify_cot_signatures(chain):
      
      for link in chain.links:
          unsigned_path = link.get_artifact_full_path('public/chain-of-trust.json')
          ed25519_signature_path = link.get_artifact_full_path('public/chain-of-trust.json.sig')
          verify_link_ed25519_cot_signature(chain, link, unsigned_path, ed25519_signature_path)
docs: Verify the signatures of the chain of trust artifacts populated in ``download_cot``.
  
      Populate each link.cot with the chain of trust json body.
  
      Args:
          chain (ChainOfTrust): the chain of trust to add to.
  
      Raises:
          CoTError: on failure.