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
int SSL_want(SSL *ssl);
int SSL_want_nothing(SSL *ssl);
int SSL_want_read(SSL *ssl);
int SSL_want_write(SSL *ssl);
int SSL_want_x509_lookup(SSL *ssl);
DESCRIPTIONSSL_want() returns state information for the SSL object ssl.
The other SSL_want_*() calls are shortcuts for the possible states
returned by SSL_want().
NOTESSSL_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
The result returned by SSL_want() should always be consistent with the
result of SSL_get_error(3).
The following return values can currently occur for SSL_want():
There is no data to be written or to be read.
There are data in the SSL buffer that must be written to the under‐
lying BIO layer in order to complete the actual SSL_*() operation.
A call to SSL_get_error(3) should return SSL_ERROR_WANT_WRITE.
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.
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 ALSOssl(3), err(3), SSL_get_error(3)0.9.7d 2002-12-01 SSL_want(3)