SSL_want(3) — Subroutines

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(
        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 );

DESCRIPTION

The SSL_want() function returns state information for the SSL object ssl.

The other SSL_want_∗() functions are shortcuts for the possible states returned by SSL_want().

NOTES

The SSL_want() function examines the internal state information of the SSL object. Its return values are similar to that of the SSL_get_error() function. Unlike SSL_get_error(), which also evaluates the error queue, the results are obtained by examining an internal state flag only. Therefore, the information must 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 the SSL_want() function should always be consistent with the result of the SSL_get_error() function.

RETURN VALUES

The following return values can 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.

The SSL_want_nothing(), SSL_want_read(), SSL_want_write(), and SSL_want_x509_lookup() functions return 1 when the corresponding condition is true or 0 otherwise.

Museum