Tribblix: manual page: gss_wrap_size

GSS_WRAP_SIZE_LIMIT(3GSS) Generic Security Services API Library Functions

NAME

gss_wrap_size_limit - allow application to determine maximum message
size with resulting output token of a specified maximum size

SYNOPSIS

cc [ flag... ] file... -lgss [ library... ]
#include <gssapi/gssapi.h>

OM_uint32 gss_process_context_token(OM_uint32 *minor_status,
const gss_ctx_id_t context_handle, int conf_req_flag,
gss_qop_t qop_req, OM_uint32 req_output_size,
OM_uint32 *max_input_size);

DESCRIPTION

The gss_wrap_size_limit() function allows an application to determine
the maximum message size that, if presented to gss_wrap() with the
same conf_req_flag and qop_req parameters, results in an output token
containing no more than req_output_size bytes. This call is intended
for use by applications that communicate over protocols that impose a
maximum message size. It enables the application to fragment messages
prior to applying protection. The GSS-API detects invalid QOP values
when gss_wrap_size_limit() is called. This routine guarantees only a
maximum message size, not the availability of specific QOP values for
message protection.

Successful completion of gss_wrap_size_limit() does not guarantee
that gss_wrap() will be able to protect a message of length
max_input_size bytes, since this ability might depend on the
availability of system resources at the time that gss_wrap() is
called.

PARAMETERS

The parameter descriptions for gss_wrap_size_limit() are as follows:

minor_status
A mechanism-specific status code.

context_handle
A handle that refers to the security over which
the messages will be sent.

conf_req_flag
Indicates whether gss_wrap() will be asked to
apply confidential protection in addition to
integrity protection. See gss_wrap(3GSS) for more
details.

qop_req
Indicates the level of protection that gss_wrap()
will be asked to provide. See gss_wrap(3GSS) for
more details.

req_output_size
The desired maximum size for tokens emitted by
gss_wrap().

max_input_size
The maximum input message size that can be
presented to gss_wrap() to guarantee that the
emitted token will be no larger than
req_output_size bytes.

ERRORS

gss_wrap_size_limit() returns one of the following status codes:

GSS_S_COMPLETE
Successful completion.

GSS_S_NO_CONTEXT
The referenced context could not be
accessed.

GSS_S_CONTEXT_EXPIRED
The context has expired.

GSS_S_BAD_QOP
The specified QOP is not supported by the
mechanism.

GSS_S_FAILURE
The underlying mechanism detected an error
for which no specific GSS status code is
defined. The mechanism-specific status code
reported by means of the minor_status
parameter details the error condition.