target = "https://www.rfc-editor.org/rfc/rfc9001#section-8.1"

# 8.1.  Protocol Negotiation
#
# QUIC requires that the cryptographic handshake provide authenticated
# protocol negotiation.  TLS uses Application-Layer Protocol
# Negotiation [ALPN] to select an application protocol.  Unless another
# mechanism is used for agreeing on an application protocol, endpoints
# MUST use ALPN for this purpose.
# 
# When using ALPN, endpoints MUST immediately close a connection (see
# Section 10.2 of [QUIC-TRANSPORT]) with a no_application_protocol TLS
# alert (QUIC error code 0x0178; see Section 4.8) if an application
# protocol is not negotiated.  While [ALPN] only specifies that servers
# use this alert, QUIC clients MUST use error 0x0178 to terminate a
# connection when ALPN negotiation fails.
# 
# An application protocol MAY restrict the QUIC versions that it can
# operate over.  Servers MUST select an application protocol compatible
# with the QUIC version that the client has selected.  The server MUST
# treat the inability to select a compatible application protocol as a
# connection error of type 0x0178 (no_application_protocol).
# Similarly, a client MUST treat the selection of an incompatible
# application protocol by a server as a connection error of type
# 0x0178.

[[spec]]
level = "MUST"
quote = '''
Unless another
mechanism is used for agreeing on an application protocol, endpoints
MUST use ALPN for this purpose.
'''

[[spec]]
level = "MUST"
quote = '''
When using ALPN, endpoints MUST immediately close a connection (see
Section 10.2 of [QUIC-TRANSPORT]) with a no_application_protocol TLS
alert (QUIC error code 0x0178; see Section 4.8) if an application
protocol is not negotiated.
'''

[[spec]]
level = "MUST"
quote = '''
While [ALPN] only specifies that servers
use this alert, QUIC clients MUST use error 0x0178 to terminate a
connection when ALPN negotiation fails.
'''

[[spec]]
level = "MAY"
quote = '''
An application protocol MAY restrict the QUIC versions that it can
operate over.
'''

[[spec]]
level = "MUST"
quote = '''
Servers MUST select an application protocol compatible
with the QUIC version that the client has selected.
'''

[[spec]]
level = "MUST"
quote = '''
The server MUST
treat the inability to select a compatible application protocol as a
connection error of type 0x0178 (no_application_protocol).
'''

[[spec]]
level = "MUST"
quote = '''
Similarly, a client MUST treat the selection of an incompatible
application protocol by a server as a connection error of type
0x0178.
'''