Client type.

Either a host name e.g., "haskell.org" or a numeric host address string consisting of a dotted decimal IPv4 address or an IPv6 address e.g., "192.168.0.1".

Authority.

Port number. Use the Num instance (i.e. use a literal) to create a PortNumber value.

>>> 1 :: PortNumber
1
>>> read "1" :: PortNumber
1
>>> show (12345 :: PortNumber)
"12345"
>>> 50000 < (51000 :: PortNumber)
True
>>> 50000 < (52000 :: PortNumber)
True
>>> 50000 + (10000 :: PortNumber)
60000

Client configuration

Default authority

When we connect to a server, we can distinguish between three names, all of which may be different:

1. The HostName, used for the DNS lookup to get the server's IP
2. The HTTP2 :authority pseudo-header
3. The TLS SNI (Server Name Indicator). This is different from (2) only in exceptional circumstances, see settingsServerNameOverride.

In most cases, however, all three names are identical, and so the default Authority is simply equal to the ServerName.

Running an HTTP/2 client over TLS (over TCP).

Running an HTTP/2 client over TCP.

Running a TLS client.

Default settings.

Key logger (TLS and H2)

Applications may wish to set this depending on the SSLKEYLOGFILE environment variable.

Default: do nothing.

Should we validate TLS certificates? (TLS and H2)

>>> settingsValidateCert defaultSettings
True

Certificate store used for validation. (TLS and H2)

Default: mempty.

Obsoleted.

How many pushed responses are contained in the cache (H2 and H2c)

>>> settingsCacheLimits defaultSettings
64

The maximum number of incoming streams on the net (H2 and H2c)

>>> settingsConcurrentStreams defaultSettings
64

The window size of a connection (H2 and H2c)

>>> settingsConnectionWindowSize defaultSettings
1048575

The window size of incoming streams (H2 and H2c)

>>> settingsStreamWindowSize defaultSettings
262144

Server name override (H2)

By default, the server name (for TLS SNI) is set based on the authority, corresponding to the HTTP2 :authority pseudo-header. In rare circumstances these two values should be different (for example in the case of domain fronting); settingsServerNameOverride can be used to give SNI a different value than :authority.

TLS session manager (H2 and TLS)

Default: noSessionManager

Try to resume a TLS session (H2 and TLS)

>>> settingsWantSessionResume defaultSettings
Nothing

Try to use 0-RTT (H2 and TLS)

This is only supported for tls >= 2.0.

>>> settingsUseEarlyData defaultSettings
False