I would appreciate a separate execuatable "tsp-client" or something that I can call to have a file timestamped.

running test.py fails with this output.

This is in a Linux Mint 20 system with python 3.8.

`
EE

ERROR: test_basic_tsp_client_operations (main.TestTSPClient)

Traceback (most recent call last):
File "./test.py", line 36, in test_basic_tsp_client_operations
signed = self.signer.sign(message)
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/signer.py", line 65, in sign
verify_result = self._verifier.verify(tst, nonce=nonce, message_digest=digest)
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/verifier.py", line 173, in verify
signing_cert = self._extract_signing_cert(signer_info, certificates=certificates)
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/verifier.py", line 123, in _extract_signing_cert
store = self._get_ca_store()
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/verifier.py", line 98, in _get_ca_store
store.load_locations(cafile=ca_pem_file, capath=ca_path) # type: ignore
AttributeError: 'X509Store' object has no attribute 'load_locations'

======================================================================
ERROR: test_set_custom_tsa (main.TestTSPClient)

Traceback (most recent call last):
File "./test.py", line 60, in test_set_custom_tsa
signed = self.signer.sign(message, signing_settings=signing_settings)
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/signer.py", line 65, in sign
verify_result = self._verifier.verify(tst, nonce=nonce, message_digest=digest)
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/verifier.py", line 173, in verify
signing_cert = self._extract_signing_cert(signer_info, certificates=certificates)
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/verifier.py", line 123, in _extract_signing_cert
store = self._get_ca_store()
File "/lvm1/home/sl/work/work23/tsr/tsp-client/tsp_client/verifier.py", line 98, in _get_ca_store
store.load_locations(cafile=ca_pem_file, capath=ca_path) # type: ignore
AttributeError: 'X509Store' object has no attribute 'load_locations'

Ran 2 tests in 0.296s

FAILED (errors=2)

'

The link to Documentation does not exist.

https://pyauth.github.io/tsp-client/

tsp-client takes a message and hashes it. This is inefficient for large files because they have to be help in memory. Python 3.11 added helper functions for efficient hashing of files: https://docs.python.org/3/library/hashlib.html#file-hashing. It would be nice if we were able to use them.

I propose the extend the interface of TSPSigner.sign() so that it takes either a message or a digest. That would allow users to pass a digest without breaking backwards compatibility.