- NAME
- SYNOPSIS
- DESCRIPTION
- NOTES
- RETURN VALUES
- SEE ALSO

# 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. Unlike SSL_get_error, 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.

The result returned by `SSL_want()` should always be consistent with the result of SSL_get_error.

# 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 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 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 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, err, SSL_get_error