1=pod
2
3=begin comment
4
5Copyright 2005 Nokia. All rights reserved.
6
7The portions of the attached software ("Contribution") is developed by
8Nokia Corporation and is licensed pursuant to the OpenSSL open source
9license.
10
11The Contribution, originally written by Mika Kousa and Pasi Eronen of
12Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
13support (see RFC 4279) to OpenSSL.
14
15No patent licenses or other rights except those expressly stated in
16the OpenSSL open source license shall be deemed granted or received
17expressly, by implication, estoppel, or otherwise.
18
19No assurances are provided by Nokia that the Contribution does not
20infringe the patent or other intellectual property rights of any third
21party or that the license provides you with all the necessary rights
22to make use of the Contribution.
23
24THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
25ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
26SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
27OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
28OTHERWISE.
29
30=end comment
31
32=head1 NAME
33
34SSL_CTX_set_psk_client_callback, SSL_set_psk_client_callback - set PSK client callback
35
36=head1 SYNOPSIS
37
38 #include <openssl/ssl.h>
39
40 void SSL_CTX_set_psk_client_callback(SSL_CTX *ctx,
41	unsigned int (*callback)(SSL *ssl, const char *hint,
42	char *identity, unsigned int max_identity_len,
43	unsigned char *psk, unsigned int max_psk_len));
44 void SSL_set_psk_client_callback(SSL *ssl,
45	unsigned int (*callback)(SSL *ssl, const char *hint,
46	char *identity, unsigned int max_identity_len,
47 	unsigned char *psk, unsigned int max_psk_len));
48
49
50=head1 DESCRIPTION
51
52A client application must provide a callback function which is called
53when the client is sending the ClientKeyExchange message to the server.
54
55The purpose of the callback function is to select the PSK identity and
56the pre-shared key to use during the connection setup phase.
57
58The callback is set using functions SSL_CTX_set_psk_client_callback()
59or SSL_set_psk_client_callback(). The callback function is given the
60connection in parameter B<ssl>, a B<NULL>-terminated PSK identity hint
61sent by the server in parameter B<hint>, a buffer B<identity> of
62length B<max_identity_len> bytes where the the resulting
63B<NULL>-terminated identity is to be stored, and a buffer B<psk> of
64length B<max_psk_len> bytes where the resulting pre-shared key is to
65be stored.
66
67=head1 NOTES
68
69Note that parameter B<hint> given to the callback may be B<NULL>.
70
71=head1 RETURN VALUES
72
73Return values from the client callback are interpreted as follows:
74
75On success (callback found a PSK identity and a pre-shared key to use)
76the length (> 0) of B<psk> in bytes is returned.
77
78Otherwise or on errors callback should return 0. In this case
79the connection setup fails.
80
81=cut
82