tests: allow TLS1.2 with RSA-PSS certs in integ tests

[lrstewart]

Release Summary:

Resolved issues:

tests #4927

Description of changes:

Our integration tests currently skip any combination of parameters that would negotiate RSA-PSS-PSS with TLS1.2. Now that we support RSA-PSS-PSS with TLS1.2, this change removes those restrictions.

Callouts

I'm sorry for the hacky string comparisons, but that's unfortunately how the integ tests currently work ;_;

Testing:

It's hard to confirm what tests we run, so I dumped the output of a successful test_s2n_client_signature_algorithms run into a file and searched it. It looks like:

...
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-ECDHE-RSA-AES128-GCM-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-ECDHE-RSA-AES256-GCM-SHA384]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-ECDHE-RSA-CHACHA20-POLY1305]
...

The commands I ran, and the results:

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | wc -l
68

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | grep TLS1.2 | wc -l
56

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | grep TLS1.2 | grep s2n_client | wc -l
28

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | grep TLS1.2 | grep s2n_server | wc -l
28

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | sed 's/^.*-OpenSSL-\(.*\)\]/\1/' | sort -u
DHE-RSA-AES128-GCM-SHA256
DHE-RSA-AES128-SHA
DHE-RSA-AES128-SHA256
DHE-RSA-AES256-GCM-SHA384
DHE-RSA-AES256-SHA
DHE-RSA-AES256-SHA256
DHE-RSA-CHACHA20-POLY1305
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-SHA
ECDHE-RSA-AES128-SHA256
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-RSA-AES256-SHA
ECDHE-RSA-AES256-SHA384
ECDHE-RSA-CHACHA20-POLY1305
TLS_AES_128_GCM_SHA256
TLS_AES_256_GCM_SHA384
TLS_CHACHA20_POLY1305_SHA256

That looks correct to me, given the full set of ciphers:

$ cat signature_algorithms.out | grep ": PASSED " | grep "OpenSSL" | sed 's/^.*-OpenSSL-\(.*\)\]/\1/' | sort -u
AES128-SHA
AES128-SHA256
AES256-SHA
AES256-SHA256
DHE-RSA-AES128-GCM-SHA256
DHE-RSA-AES128-SHA
DHE-RSA-AES128-SHA256
DHE-RSA-AES256-GCM-SHA384
DHE-RSA-AES256-SHA
DHE-RSA-AES256-SHA256
DHE-RSA-CHACHA20-POLY1305
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES128-SHA
ECDHE-ECDSA-AES128-SHA256
ECDHE-ECDSA-AES256-GCM-SHA384
ECDHE-ECDSA-AES256-SHA
ECDHE-ECDSA-AES256-SHA384
ECDHE-ECDSA-CHACHA20-POLY1305
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-SHA
ECDHE-RSA-AES128-SHA256
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-RSA-AES256-SHA
ECDHE-RSA-AES256-SHA384
ECDHE-RSA-CHACHA20-POLY1305
TLS_AES_128_GCM_SHA256
TLS_AES_256_GCM_SHA384
TLS_CHACHA20_POLY1305_SHA256

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[jouho]

I assume this is the "hacky string comparisons", but I'm trying to understand the context here. Is RSA-PSS only compatible with ECDHE key exchange?

[lrstewart]

RSA-PSS certs can't be used with RSA key exchange (that's what Sam was asking about here). That's because RSA-PSS certs can only be used for signing, not encryption, and RSA key exchange involves encryption. RSA-PSS certs are basically just RSA certs with safer usage rules.

But as I look at this again, checking for "ECDHE" is probably too restrictive. I'll relax it to "DHE". I can't go all the way to just checking for no "RSA", because 1) legacy cipher suites assume RSA without putting it in their names 2) "RSA" could also refer to the auth method instead of the kex method.

[lrstewart]

Updated, and I updated the testing results in the description. And here's the result of only non-ECDHE:

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | grep TLS1.2 | grep -v ECDHE | wc -l
28

$ cat signature_algorithms.out | grep ": PASSED " | grep pss_pss | grep TLS1.2 | grep -v ECDHE
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-GCM-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-GCM-SHA384]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-CHACHA20-POLY1305]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-GCM-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-GCM-SHA384]
293: PASSED test_signature_algorithms.py::test_s2n_server_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-CHACHA20-POLY1305]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-GCM-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-GCM-SHA384]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-CHACHA20-POLY1305]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES128-GCM-SHA256]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-AES256-GCM-SHA384]
293: PASSED test_signature_algorithms.py::test_s2n_client_signature_algorithms[no-client-auth-rsa_pss_pss_sha256-RSA_PSS_2048_SHA256-TLS1.2-S2N-OpenSSL-DHE-RSA-CHACHA20-POLY1305]

[jouho]

Very interesting. Thank you for explaining!