ranch_ssl
=========

The `ranch_ssl` module implements an SSL Ranch transport.

Types
-----

### ssl_opt() = {alpn_preferred_protocols, [binary()]}
	| {cacertfile, string()}
	| {cacerts, [public_key:der_encoded()]}
	| {cert, public_key:der_encoded()}
	| {certfile, string()}
	| {ciphers, [ssl:erl_cipher_suite()] | string()}
	| {client_renegotiation, boolean()}
	| {crl_cache, {module(), {internal | any(), list()}}}
	| {crl_check, boolean() | peer | best_effort}
	| {depth, 0..255}
	| {dh, public_key:der_encoded()}
	| {dhfile, string()}
	| {fail_if_no_peer_cert, boolean()}
	| {hibernate_after, integer() | undefined}
	| {honor_cipher_order, boolean()}
	| {key, {'RSAPrivateKey' | 'DSAPrivateKey' | 'PrivateKeyInfo', public_key:der_encoded()}}
	| {keyfile, string()}
	| {log_alert, boolean()}
	| {next_protocols_advertised, [binary()]}
	| {partial_chain, fun(([public_key:der_encoded()]) -> {trusted_ca, public_key:der_encoded()} | unknown_ca)}
	| {password, string()}
	| {psk_identity, string()}
	| {reuse_session, fun()}
	| {reuse_sessions, boolean()}
	| {secure_renegotiate, boolean()}
	| {sni_fun, fun()}
	| {sni_hosts, [{string(), ssl_opt()}]}
	| {user_lookup_fun, {fun(), any()}}
	| {verify, ssl:verify_type()}
	| {verify_fun, {fun(), any()}}
	| {versions, [atom()]}.

> SSL-specific listen options.

### opt() = ranch_tcp:opt() | ssl_opt()

> Listen options.

### opts() = [opt()]

> List of listen options.

Option descriptions
-------------------

Specifying a certificate is mandatory, either through the `cert`
or the `certfile` option. None of the other options are required.

The default value is given next to the option name.

 -  alpn_preferred_protocols
   -  Perform Application-Layer Protocol Negotiation with the given list of preferred protocols.
 -  cacertfile
   -  Path to PEM encoded trusted certificates file used to verify peer certificates.
 -  cacerts
   -  List of DER encoded trusted certificates.
 -  cert
   -  DER encoded user certificate.
 -  certfile
   -  Path to the PEM encoded user certificate file. May also contain the private key.
 -  ciphers
   -  List of ciphers that clients are allowed to use.
 -  client_renegotiation (true)
   -  Whether to allow client-initiated renegotiation.
 -  crl_cache ({ssl_crl_cache, {internal, []}})
   -  Customize the module used to cache Certificate Revocation Lists.
 -  crl_check (false)
   -  Whether to perform CRL check on all certificates in the chain during validation.
 -  depth (1)
   -  Maximum of intermediate certificates allowed in the certification path.
 -  dh
   -  DER encoded Diffie-Hellman parameters.
 -  dhfile
   -  Path to the PEM encoded Diffie-Hellman parameters file.
 -  fail_if_no_peer_cert (false)
   -  Whether to refuse the connection if the client sends an empty certificate.
 -  hibernate_after (undefined)
   -  Time in ms after which SSL socket processes go into hibernation to reduce memory usage.
 -  honor_cipher_order (false)
   -  If true, use the server's preference for cipher selection. If false, use the client's preference.
 -  key
   -  DER encoded user private key.
 -  keyfile
   -  Path to the PEM encoded private key file, if different than the certfile.
 -  log_alert (true)
   -  If false, error reports will not be displayed.
 -  next_protocols_advertised
   -  List of protocols to send to the client if it supports the Next Protocol extension.
 -  nodelay (true)
   -  Whether to enable TCP_NODELAY.
 -  partial_chain
   -  Claim an intermediate CA in the chain as trusted.
 -  password
   -  Password to the private key file, if password protected.
 -  psk_identity
   -  Provide the given PSK identity hint to the client during the handshake.
 -  reuse_session
   -  Custom policy to decide whether a session should be reused.
 -  reuse_sessions (false)
   -  Whether to allow session reuse.
 -  secure_renegotiate (false)
   -  Whether to reject renegotiation attempts that do not conform to RFC5746.
 -  sni_fun
   -  Function called when the client requests a host using Server Name Indication. Returns options to apply.
 -  sni_hosts
   -  Options to apply for the host that matches what the client requested with Server Name Indication.
 -  user_lookup_fun
   -  Function called to determine the shared secret when using PSK, or provide parameters when using SRP.
 -  verify (verify_none)
   -  Use `verify_peer` to request a certificate from the client.
 -  verify_fun
   -  Custom policy to decide whether a client certificate is valid.
 -  versions
   -  TLS protocol versions that will be supported.

Note that the client will not send a certificate unless the
value for the `verify` option is set to `verify_peer`. This
means that the `fail_if_no_peer_cert` only apply when combined
with the `verify` option. The `verify_fun` option allows
greater control over the client certificate validation.

The options `sni_fun` and `sni_hosts` are mutually exclusive.

Exports
-------

None.