A question about signature algorithm

[luckNuma26]

When I used test-invalid-version.py to test OpenSSL 1.1.1t 7 Feb 2023, the sanity test passed,
but when I tested OpenSSL 3.0.3 3 May 2022, the sanity test is fail

openssl s_server -key /tmp/localhost.key -cert /tmp/localhost.crt -www
Using default temp DH parameters
ACCEPT
80E28D399F7F0000:error:0A000076:SSL routines:tls_choose_sigalg:no suitable signature algorithm:ssl/t1_lib.c:3334:
80E28D399F7F0000:error:0A00018C:SSL routines:tls_early_post_process_client_hello:version too low:ssl/statem/statem_srvr.c:1721:
80E28D399F7F0000:error:0A000076:SSL routines:tls_choose_sigalg:no suitable signature algorithm:ssl/t1_lib.c:3334:

I know add extension of ClientHello, for OpenSSL 3.0.3 3 May 2022 sanity test can Pass，

ext[ExtensionType.signature_algorithms] = \
            SignatureAlgorithmsExtension().create(RSA_PSS_RSAE_ALL)

If l don't add extensions, why can OpenSSL 1.1.1t 7 Feb 2023 pass but OpenSSL 3.0.3 3 May 2022 fail,
could you help me ?

[tomato42]

openssl 3.0 is unnecessarily strict, and will refuse serving a certificate with anything but SHA-1 if the client doesn't advertise signature_algorithms with additional signature algorithms, even if those signature algorithms aren't used in the TLS connection (as is the case for all TLS_RSA_* ciphers)

The test case should be updated to also working with servers that only support DHE/ECDHE key exchange, also to address #563

[luckNuma26]

But when I use no signature algorithm extension of test-invalid-version.py to test OpenSSL 3.0.3 3 May 2022,Why didn't it turn out no suitable signature algorithm

openssl s_server -key  clientRSAPSSKey.pem   -cert clientRSAPSSCert.pem  -www
80A26872A87F0000:error:0A0000C1:SSL routines:tls_post_process_client_hello:no shared cipher:ssl/statem/statem_srvr.c:2384:

If I were to test OpenSSL 1.1.1t 7 Feb 2023

openssl s_server -key  clientRSAPSSKey.pem   -cert clientRSAPSSCert.pem  -www
80E28D399F7F0000:error:0A000076:SSL routines:tls_choose_sigalg:no suitable signature algorithm:ssl/t1_lib.c:3334

As a beginner, I looked up some information, but I still don't understand. Could you tell me more details? Thank you very much

[tomato42]

error messages from openssl are quite famously unreliable