=head1 NAME
-SSL_CTX_use_psk_identity_hint, SSL_use_psk_identity_hint,
-SSL_CTX_set_psk_server_callback, SSL_set_psk_server_callback - set PSK
-identity hint to use
+SSL_psk_server_cb_func,
+SSL_psk_find_session_cb_func,
+SSL_CTX_use_psk_identity_hint,
+SSL_use_psk_identity_hint,
+SSL_CTX_set_psk_server_callback,
+SSL_set_psk_server_callback,
+SSL_CTX_set_psk_find_session_callback,
+SSL_set_psk_find_session_callback
+- set PSK identity hint to use
=head1 SYNOPSIS
#include <openssl/ssl.h>
+ typedef unsigned int (*SSL_psk_server_cb_func)(SSL *ssl,
+ const char *identity,
+ unsigned char *psk,
+ unsigned int max_psk_len);
+
+ typedef int (*SSL_psk_find_session_cb_func)(SSL *ssl,
+ const unsigned char *identity,
+ size_t identity_len,
+ SSL_SESSION **sess);
+
int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx, const char *hint);
int SSL_use_psk_identity_hint(SSL *ssl, const char *hint);
- void SSL_CTX_set_psk_server_callback(SSL_CTX *ctx,
- unsigned int (*callback)(SSL *ssl,
- const char *identity,
- unsigned char *psk,
- int max_psk_len));
- void SSL_set_psk_server_callback(SSL *ssl,
- unsigned int (*callback)(SSL *ssl,
- const char *identity,
- unsigned char *psk,
- int max_psk_len));
+ void SSL_CTX_set_psk_server_callback(SSL_CTX *ctx, SSL_psk_server_cb_func cb);
+ void SSL_set_psk_server_callback(SSL *ssl, SSL_psk_server_cb_func cb);
+ void SSL_CTX_set_psk_find_session_callback(SSL_CTX *ctx,
+ SSL_psk_find_session_cb_func cb);
+ void SSL_set_psk_find_session_callback(SSL *s, SSL_psk_find_session_cb_func cb);
=head1 DESCRIPTION
-SSL_CTX_use_psk_identity_hint() sets the given B<NULL>-terminated PSK
-identity hint B<hint> to SSL context object
-B<ctx>. SSL_use_psk_identity_hint() sets the given B<NULL>-terminated
-PSK identity hint B<hint> to SSL connection object B<ssl>. If B<hint>
-is B<NULL> the current hint from B<ctx> or B<ssl> is deleted.
+TLSv1.3 Pre-Shared Keys (PSKs) and PSKs for TLSv1.2 and below are not
+compatible.
+
+Identity hints are not relevant for TLSv1.3. A server application wishing to use
+PSK ciphersuites for TLSv1.2 and below may call SSL_CTX_use_psk_identity_hint()
+to set the given B<NULL>-terminated PSK identity hint B<hint> for SSL context
+object B<ctx>. SSL_use_psk_identity_hint() sets the given B<NULL>-terminated PSK
+identity hint B<hint> for the SSL connection object B<ssl>. If B<hint> is
+B<NULL> the current hint from B<ctx> or B<ssl> is deleted.
-In the case where PSK identity hint is B<NULL>, the server
-does not send the ServerKeyExchange message to the client.
+In the case where PSK identity hint is B<NULL>, the server does not send the
+ServerKeyExchange message to the client.
-A server application must provide a callback function which is called
-when the server receives the ClientKeyExchange message from the
+A server application for TLSv1.2 and below must provide a callback function
+which is called when the server receives the ClientKeyExchange message from the
client. The purpose of the callback function is to validate the
received PSK identity and to fetch the pre-shared key used during the
-connection setup phase. The callback is set using functions
-SSL_CTX_set_psk_server_callback() or
-SSL_set_psk_server_callback(). The callback function is given the
-connection in parameter B<ssl>, B<NULL>-terminated PSK identity sent
-by the client in parameter B<identity>, and a buffer B<psk> of length
-B<max_psk_len> bytes where the pre-shared key is to be stored.
-
+connection setup phase. The callback is set using the functions
+SSL_CTX_set_psk_server_callback() or SSL_set_psk_server_callback(). The callback
+function is given the connection in parameter B<ssl>, B<NULL>-terminated PSK
+identity sent by the client in parameter B<identity>, and a buffer B<psk> of
+length B<max_psk_len> bytes where the pre-shared key is to be stored.
+
+A client application wishing to use TLSv1.3 PSKs must set a different callback
+using either SSL_CTX_set_psk_use_session_callback() or
+SSL_set_psk_use_session_callback() as appropriate.
+
+The callback function is given a reference to the SSL connection in B<ssl> and
+an identity in B<identity> of length B<identity_len>. The callback function
+should identify an SSL_SESSION object that provides the PSK details and store it
+in B<*sess>. The SSL_SESSION object should, as a minimum, set the master key,
+the ciphersuite and the protocol version. See
+L<SSL_CTX_set_psk_use_session_callback(3)> for details.
+
+It is also possible for the callback to succeed but not supply a PSK. In this
+case no PSK will be used but the handshake will continue. To do this the
+callback should return successfully and ensure that B<*sess> is
+NULL.
=head1 RETURN VALUES
SSL_CTX_use_psk_identity_hint() and SSL_use_psk_identity_hint() return
1 on success, 0 otherwise.
-Return values from the server callback are interpreted as follows:
+Return values from the TLSv1.2 and below server callback are interpreted as
+follows:
=over 4
=back
+The SSL_psk_find_session_cb_func callback should return 1 on success or 0 on
+failure. In the event of failure the connection setup fails.
+
=head1 COPYRIGHT
-Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2006-2017 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
projects / openssl.git / blobdiff