B<ed25519>, or B<rsa_pss_pss_sha256>. Additional providers may make available
further algorithms via the TLS-SIGALG capability.
Signature scheme names and public key algorithm names (but not the hash names)
-in the B<algoirithm+hash> form are case-insensitive.
+in the B<algorithm+hash> form are case-insensitive.
See L<provider-base(7)>.
If this option is not set then all signature algorithms supported by all
specified using the IANA name, e.g., B<ecdsa_secp256r1_sha256>, B<ed25519>,
or B<rsa_pss_pss_sha256>.
Signature scheme names and public key algorithm names (but not the hash names)
-in the B<algoirithm+hash> form are case-insensitive.
+in the B<algorithm+hash> form are case-insensitive.
Additional providers may make available further signature schemes via the
TLS_SIGALG capability. See L<provider-base(7)/CAPABILITIES>.
algorithm and a digest separated by B<+>, or a TLS 1.3-style named
SignatureScheme such as rsa_pss_pss_sha256.
Signature scheme names and public key algorithm names (but not the digest
-names) in the B<algoirithm+hash> form are case-insensitive.
+names) in the B<algorithm+hash> form are case-insensitive.
If a list entry is preceded with the C<?> character, it will be ignored if an
implementation is missing.