5 SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write,
6 SSL_want_x509_lookup, SSL_want_retry_verify, SSL_want_async, SSL_want_async_job,
7 SSL_want_client_hello_cb - obtain state information TLS/SSL I/O operation
11 #include <openssl/ssl.h>
13 int SSL_want(const SSL *ssl);
14 int SSL_want_nothing(const SSL *ssl);
15 int SSL_want_read(const SSL *ssl);
16 int SSL_want_write(const SSL *ssl);
17 int SSL_want_x509_lookup(const SSL *ssl);
18 int SSL_want_retry_verify(const SSL *ssl);
19 int SSL_want_async(const SSL *ssl);
20 int SSL_want_async_job(const SSL *ssl);
21 int SSL_want_client_hello_cb(const SSL *ssl);
25 SSL_want() returns state information for the SSL object B<ssl>.
27 The other SSL_want_*() calls are shortcuts for the possible states returned
32 SSL_want() examines the internal state information of the SSL object. Its
33 return values are similar to that of L<SSL_get_error(3)>.
34 Unlike L<SSL_get_error(3)>, which also evaluates the
35 error queue, the results are obtained by examining an internal state flag
36 only. The information must therefore only be used for normal operation under
37 nonblocking I/O. Error conditions are not handled and must be treated
38 using L<SSL_get_error(3)>.
40 The result returned by SSL_want() should always be consistent with
41 the result of L<SSL_get_error(3)>.
45 The following return values can currently occur for SSL_want():
51 There is no data to be written or to be read.
55 There are data in the SSL buffer that must be written to the underlying
56 B<BIO> layer in order to complete the actual SSL_*() operation.
57 A call to L<SSL_get_error(3)> should return B<SSL_ERROR_WANT_WRITE>.
61 More data must be read from the underlying B<BIO> layer in order to
62 complete the actual SSL_*() operation.
63 A call to L<SSL_get_error(3)> should return B<SSL_ERROR_WANT_READ>.
67 The operation did not complete because an application callback set by
68 SSL_CTX_set_client_cert_cb() has asked to be called again.
69 A call to L<SSL_get_error(3)> should return B<SSL_ERROR_WANT_X509_LOOKUP>.
71 =item SSL_RETRY_VERIFY
73 The operation did not complete because an application callback set by
74 SSL_CTX_set_cert_verify_callback() has asked to be called again.
75 A call to L<SSL_get_error(3)> should return B<SSL_ERROR_WANT_RETRY_VERIFY>.
77 =item SSL_ASYNC_PAUSED
79 An asynchronous operation partially completed and was then paused. See
80 L<SSL_get_all_async_fds(3)>. A call to L<SSL_get_error(3)> should return
81 B<SSL_ERROR_WANT_ASYNC>.
83 =item SSL_ASYNC_NO_JOBS
85 The asynchronous job could not be started because there were no async jobs
86 available in the pool (see ASYNC_init_thread(3)). A call to L<SSL_get_error(3)>
87 should return B<SSL_ERROR_WANT_ASYNC_JOB>.
89 =item SSL_CLIENT_HELLO_CB
91 The operation did not complete because an application callback set by
92 SSL_CTX_set_client_hello_cb() has asked to be called again.
93 A call to L<SSL_get_error(3)> should return B<SSL_ERROR_WANT_CLIENT_HELLO_CB>.
97 SSL_want_nothing(), SSL_want_read(), SSL_want_write(),
98 SSL_want_x509_lookup(), SSL_want_retry_verify(),
99 SSL_want_async(), SSL_want_async_job(), and SSL_want_client_hello_cb()
100 return 1 when the corresponding condition is true or 0 otherwise.
104 L<ssl(7)>, L<SSL_get_error(3)>
108 The SSL_want_client_hello_cb() function and the SSL_CLIENT_HELLO_CB return value
109 were added in OpenSSL 1.1.1.
113 Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
115 Licensed under the Apache License 2.0 (the "License"). You may not use
116 this file except in compliance with the License. You can obtain a copy
117 in the file LICENSE in the source distribution or at
118 L<https://www.openssl.org/source/license.html>.