SSL_want(3) OpenSSL SSL_want(3)
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);
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().
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
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.
ssl(3), openssl_err(3), SSL_get_error(3)
3rd Berkeley Distribution 0.9.7d SSL_want(3)