csu3_am335x/EVSE/GPL/openssl-1.0.2g/release/openssl/man/man3/SSL_want.3

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.\" ========================================================================
.\"
.IX Title "SSL_want 3"
.TH SSL_want 3 "2019-09-12" "1.0.2g" "OpenSSL"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.nh
.SH "NAME"
SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write, SSL_want_x509_lookup \- 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);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
\&\fISSL_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 \fISSL_want()\fR.
.SH "NOTES"
.IX Header "NOTES"
\&\fISSL_want()\fR examines the internal state information of the \s-1SSL\s0 object. Its
return values are similar to that of \fISSL_get_error\fR\|(3).
Unlike \fISSL_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
non-blocking I/O. Error conditions are not handled and must be treated
using \fISSL_get_error\fR\|(3).
.PP
The result returned by \fISSL_want()\fR should always be consistent with
the result of \fISSL_get_error\fR\|(3).
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
The following return values can currently occur for \fISSL_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 \fISSL_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 \fISSL_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
\&\fISSL_CTX_set_client_cert_cb()\fR has asked to be called again.
A call to \fISSL_get_error\fR\|(3) should return
\&\s-1SSL_ERROR_WANT_X509_LOOKUP.\s0
.PP
\&\fISSL_want_nothing()\fR, \fISSL_want_read()\fR, \fISSL_want_write()\fR, \fISSL_want_x509_lookup()\fR
return 1, when the corresponding condition is true or 0 otherwise.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fIssl\fR\|(3), \fIerr\fR\|(3), \fISSL_get_error\fR\|(3)