ssl:handshake/3 fails with cert_and_key_required and {handshake, hello} specified

[sg2342]

Describe the bug

With 7a07239 ssh:handshake/3 requires cert and key to be present.
It must not require cert and key if {handshake, hello} is set because the actual cert and key to be used might be set later in ssl:handshake_continue/3 based on information returned by ssh:handshake/3 (e.g. the SNI hostname).

To Reproduce

Erlang/OTP 27 [erts-15.1.2] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns] [dtrace] [sharing-preserving]

Eshell V15.1.2 (press Ctrl+G to abort, type help(). for help)
1> ssl:start().
ok
2> {ok, ListenSocket} = gen_tcp:listen(1234, [binary, {active, false}, inet, {reuseaddr, true}]).
{ok,#Port<0.3>}
3> {ok, TcpSocket} = gen_tcp:accept(ListenSocket).
{ok,#Port<0.4>}
4> ssl:handshake(TcpSocket, [{handshake, hello}, {versions, ['tlsv1.3']}], 5000).
{error,{options,{certs_keys,cert_and_key_required}}}

Expected behavior

Erlang/OTP 26 [erts-14.2.5.4] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns] [dtrace] [sharing-preserving]

Eshell V14.2.5.4 (press Ctrl+G to abort, type help(). for help)
1> ssl:start().
ok
2> {ok, ListenSocket} = gen_tcp:listen(1234, [binary, {active, false}, inet, {reuseaddr, true}]).
{ok,#Port<0.3>}
3> {ok, TcpSocket} = gen_tcp:accept(ListenSocket).
{ok,#Port<0.4>}
4> ssl:handshake(TcpSocket, [{handshake, hello}, {versions, ['tlsv1.3']}], 5000).
{ok,{sslsocket,{gen_tcp,#Port<0.4>,tls_connection,
                        [{session_id_tracker,not_relevant}]},
               [<0.120.0>,<0.119.0>]},
    #{cookie => undefined,
      signature_algs =>
          [ecdsa_secp256r1_sha256,ecdsa_secp384r1_sha384,
           ecdsa_secp521r1_sha512,eddsa_ed25519,eddsa_ed448,
           rsa_pss_pss_sha256,rsa_pss_pss_sha384,rsa_pss_pss_sha512,
           rsa_pss_rsae_sha256,rsa_pss_rsae_sha384,rsa_pss_rsae_sha512,
           rsa_pkcs1_sha256,rsa_pkcs1_sha384,rsa_pkcs1_sha512,
           {sha224,ecdsa},
           {sha224,rsa},
           {sha224,dsa},
           {sha256,dsa},
           {sha384,dsa},
           {sha512,dsa}],
      certificate_authorities => undefined,
      signature_algs_cert => undefined,use_srtp => undefined,
      elliptic_curves => [secp256r1],
      client_hello_versions => [{3,4},{3,3},{3,2},{3,1}],
      pre_shared_key => undefined,sni => "foo.example.com",
      key_share =>
          [{key_share_entry,secp256r1,
                            <<4,137,42,64,148,54,117,21,149,209,216,45,111,171,57,
                              51,132,68,246,124,135,...>>}],
      alpn => undefined,
      ec_point_formats => [0,1,2],
      psk_key_exchange_modes => [psk_dhe_ke]}}
5>

Affected versions
OTP-27.2
OTP-27.1.3
OTP-27.1.2
OTP-27.1.1
OTP-27.1
OTP-27.0.1
OTP-27.0
OTP-27.0-rc3
OTP-27.0-rc2
OTP-27.0-rc1

Additional context

Workaround (bogus cert and key):

ssl:handshake(TcpSocket, [{handshake, hello}, {versions, ['tlsv1.3']}, {key, #{algorithm => eddsa, sign_fun => undefined}},{cert, <<>>}}], 5000).

[IngelaAndin]

You have a point, we will discuss it internally and come back to you.