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Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "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 .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& #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); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\fBSSL_want()\fR returns state information for the \s-1SSL\s0 object \fBssl\fR. .PP The other SSL_want_*() calls are shortcuts for the possible states returned by \fBSSL_want()\fR. .SH "NOTES" .IX Header "NOTES" \&\fBSSL_want()\fR examines the internal state information of the \s-1SSL\s0 object. Its return values are similar to that of \fBSSL_get_error\fR\|(3). Unlike \fBSSL_get_error\fR\|(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 nonblocking I/O. Error conditions are not handled and must be treated using \fBSSL_get_error\fR\|(3). .PP The result returned by \fBSSL_want()\fR should always be consistent with the result of \fBSSL_get_error\fR\|(3). .SH "RETURN VALUES" .IX Header "RETURN VALUES" The following return values can currently occur for \fBSSL_want()\fR: .IP "\s-1SSL_NOTHING\s0" 4 .IX Item "SSL_NOTHING" There is no data to be written or to be read. .IP "\s-1SSL_WRITING\s0" 4 .IX Item "SSL_WRITING" There are data in the \s-1SSL\s0 buffer that must be written to the underlying \&\fB\s-1BIO\s0\fR layer in order to complete the actual SSL_*() operation. A call to \fBSSL_get_error\fR\|(3) should return \&\s-1SSL_ERROR_WANT_WRITE.\s0 .IP "\s-1SSL_READING\s0" 4 .IX Item "SSL_READING" More data must be read from the underlying \fB\s-1BIO\s0\fR layer in order to complete the actual SSL_*() operation. A call to \fBSSL_get_error\fR\|(3) should return \&\s-1SSL_ERROR_WANT_READ.\s0 .IP "\s-1SSL_X509_LOOKUP\s0" 4 .IX Item "SSL_X509_LOOKUP" The operation did not complete because an application callback set by \&\fBSSL_CTX_set_client_cert_cb()\fR has asked to be called again. A call to \fBSSL_get_error\fR\|(3) should return \&\s-1SSL_ERROR_WANT_X509_LOOKUP.\s0 .IP "\s-1SSL_ASYNC_PAUSED\s0" 4 .IX Item "SSL_ASYNC_PAUSED" An asynchronous operation partially completed and was then paused. See \&\fBSSL_get_all_async_fds\fR\|(3). A call to \fBSSL_get_error\fR\|(3) should return \&\s-1SSL_ERROR_WANT_ASYNC.\s0 .IP "\s-1SSL_ASYNC_NO_JOBS\s0" 4 .IX Item "SSL_ASYNC_NO_JOBS" The asynchronous job could not be started because there were no async jobs available in the pool (see \fBASYNC_init_thread\fR\|(3)). A call to \fBSSL_get_error\fR\|(3) should return \s-1SSL_ERROR_WANT_ASYNC_JOB.\s0 .IP "\s-1SSL_CLIENT_HELLO_CB\s0" 4 .IX Item "SSL_CLIENT_HELLO_CB" The operation did not complete because an application callback set by \&\fBSSL_CTX_set_client_hello_cb()\fR has asked to be called again. A call to \fBSSL_get_error\fR\|(3) should return \&\s-1SSL_ERROR_WANT_CLIENT_HELLO_CB.\s0 .PP \&\fBSSL_want_nothing()\fR, \fBSSL_want_read()\fR, \fBSSL_want_write()\fR, \fBSSL_want_x509_lookup()\fR, \&\fBSSL_want_async()\fR, \fBSSL_want_async_job()\fR, and \fBSSL_want_client_hello_cb()\fR return 1, when the corresponding condition is true or 0 otherwise. .SH "SEE ALSO" .IX Header "SEE ALSO" \&\fBssl\fR\|(7), \fBSSL_get_error\fR\|(3) .SH "HISTORY" .IX Header "HISTORY" The \fBSSL_want_client_hello_cb()\fR function and the \s-1SSL_CLIENT_HELLO_CB\s0 return value were added in OpenSSL 1.1.1. .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 2001\-2020 The OpenSSL Project Authors. All Rights Reserved. .PP Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.