NAME
SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write, SSL_want_x509_lookup, SSL_want_async, SSL_want_async_job, SSL_want_client_hello_cb - obtain state information TLS/SSL I/O operation
SYNOPSIS
#include <openssl/ssl.h>
int SSL_want(const SSL *ssl);
int SSL_want_nothing(const SSL *ssl);
int SSL_want_read(const SSL *ssl);
int SSL_want_write(const SSL *ssl);
int SSL_want_x509_lookup(const SSL *ssl);
int SSL_want_async(const SSL *ssl);
int SSL_want_async_job(const SSL *ssl);
int SSL_want_client_hello_cb(const SSL *ssl);
DESCRIPTION
SSL_want() returns state information for the SSL object ssl.
The other SSL_want_*() calls are shortcuts for the possible states returned by SSL_want().
NOTES
SSL_want() examines the internal state information of the SSL object. Its return values are similar to that of SSL_get_error(3). Unlike SSL_get_error(3), which also evaluates the error queue, the results are obtained by examining an internal state flag only. The information must therefore only be used for normal operation under non-blocking I/O. Error conditions are not handled and must be treated using SSL_get_error(3).
The result returned by SSL_want() should always be consistent with the result of SSL_get_error(3).
RETURN VALUES
The following return values can currently occur for SSL_want():
- SSL_NOTHING
-
There is no data to be written or to be read.
- SSL_WRITING
-
There are data in the SSL buffer that must be written to the underlying BIO layer in order to complete the actual SSL_*() operation. A call to SSL_get_error(3) should return SSL_ERROR_WANT_WRITE.
- SSL_READING
-
More data must be read from the underlying BIO layer in order to complete the actual SSL_*() operation. A call to SSL_get_error(3) should return SSL_ERROR_WANT_READ.
- SSL_X509_LOOKUP
-
The operation did not complete because an application callback set by SSL_CTX_set_client_cert_cb() has asked to be called again. A call to SSL_get_error(3) should return SSL_ERROR_WANT_X509_LOOKUP.
- SSL_ASYNC_PAUSED
-
An asynchronous operation partially completed and was then paused. See SSL_get_all_async_fds(3). A call to SSL_get_error(3) should return SSL_ERROR_WANT_ASYNC.
- SSL_ASYNC_NO_JOBS
-
The asynchronous job could not be started because there were no async jobs available in the pool (see ASYNC_init_thread(3)). A call to SSL_get_error(3) should return SSL_ERROR_WANT_ASYNC_JOB.
- SSL_CLIENT_HELLO_CB
-
The operation did not complete because an application callback set by SSL_CTX_set_client_hello_cb() has asked to be called again. A call to SSL_get_error(3) should return SSL_ERROR_WANT_CLIENT_HELLO_CB.
SSL_want_nothing(), SSL_want_read(), SSL_want_write(), SSL_want_x509_lookup(), SSL_want_async(), SSL_want_async_job(), and SSL_want_client_hello_cb() return 1, when the corresponding condition is true or 0 otherwise.
SEE ALSO
HISTORY
SSL_want_client_hello_cb() and SSL_CLIENT_HELLO_CB were added in OpenSSL 1.1.1.
COPYRIGHT
Copyright 2001-2017 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 in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.