SSL_CTX_USE_PSK_IDENT... BSD Library Functions Manual SSL_CTX_USE_PSK_IDENT...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
SYNOPSIS
#include <openssl/ssl.h>
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));
DESCRIPTIONSSL_CTX_use_psk_identity_hint() sets the given NULL-terminated PSK iden‐
tity hint hint to SSL context object ctx. SSL_use_psk_identity_hint()
sets the given NULL-terminated PSK identity hint hint to SSL connection
object ssl. If hint is NULL the current hint from ctx or ssl is deleted.
In the case where PSK identity hint is 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 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 ssl,
NULL-terminated PSK identity sent by the client in parameter identity,
and a buffer psk of length max_psk_len bytes where the pre-shared key is
to be stored.
RETURN VALUESSSL_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:
>0 PSK identity was found and the server callback has provided the
PSK successfully in parameter psk. Return value is the length of
psk in bytes. It is an error to return a value greater than
max_psk_len.
If the PSK identity was not found but the callback instructs the
protocol to continue anyway, the callback must provide some ran‐
dom data to psk and return the length of the random data, so the
connection will fail with “decryption_error” before it will be
finished completely.
0 PSK identity was not found. An “unknown_psk_identity” alert mes‐
sage will be sent and the connection setup fails.
BSD April 24, 2024 BSD
