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SSL_want(3)                         OpenSSL                        SSL_want(3)

NAME
       SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write,
       SSL_want_x509_lookup - 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);
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_want_nothing(), SSL_want_read(), SSL_want_write(),
       SSL_want_x509_lookup() return 1, when the corresponding condition is
       true or 0 otherwise.
SEE ALSO
       ssl(3), err(3), SSL_get_error(3)

1.0.2k                            2017-01-26                       SSL_want(3)