freebsd-nq/lib/libgssapi/gss_wrap_size_limit.3
Doug Rabson c0b9f4fe65 Add a new extensible GSS-API layer which can support GSS-API plugins,
similar the the Solaris implementation. Repackage the krb5 GSS mechanism
as a plugin library for the new implementation. This also includes a
comprehensive set of manpages for the GSS-API functions with text mostly
taken from the RFC.

Reviewed by: Love Hörnquist Åstrand <lha@it.su.se>, ru (build system), des (openssh parts)
2005-12-29 14:40:22 +00:00

164 lines
5.7 KiB
Groff

.\" -*- nroff -*-
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.\" Copyright (c) 2005 Doug Rabson
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.\" The following commands are required for all man pages.
.Dd November 12, 2005
.Os
.Dt GSS_WRAP_SIZE_LIMIT 3 PRM
.Sh NAME
.Nm gss_wrap_size_limit
.Nd Determine maximum message sizes
.\" This next command is for sections 2 and 3 only.
.\" .Sh LIBRARY
.Sh SYNOPSIS
.In "gssapi/gssapi.h"
.Ft OM_uint32
.Fo gss_wrap_size_limit
.Fa "OM_uint32 *minor_status"
.Fa "const gss_ctx_id_t context_handle"
.Fa "int conf_req_flag"
.Fa "gss_qop_t qop_req"
.Fa "OM_uint32 req_output_size"
.Fa "OM_uint32 *max_input_size"
.Fc
.Sh DESCRIPTION
Allows an application to determine the maximum message size that,
if presented to
.Xr gss_wrap 3
with the same
.Dv conf_req_flag
and
.Dv qop_req
parameters,
will result in an output token containing no more than
.Dv req_output_size
bytes.
.Pp
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.
.Pp
GSS-API implementations are recommended but not required to detect
invalid QOP values when
.Fn gss_wrap_size_limit
is called.
This routine guarantees only a maximum message size,
not the availability of specific QOP values for message protection.
.Pp
Successful completion of this call does not guarantee that
.Xr gss_wrap 3
will be able to protect a message of length max_input_size bytes,
since this ability may depend on the availability of system resources
at the time that
.Xr gss_wrap 3
is called.
However, if the implementation itself imposes an upper limit on
the length of messages that may be processed by gss_wrap,
the implementation should not return a value via
.Dv max_input_bytes
that is greater than this length.
.Sh PARAMETERS
.Bl -tag
.It minor_status
Mechanism specific status code.
.It context_handle
A handle that refers to the security over which the messages will be sent.
.It conf_req_flag
Indicates whether
.Xr gss_wrap 3
will be asked to apply confidentiality protection
in addition to integrity protection.
.It qop_req
Indicates the level of protection that
.Xr gss_wrap 3
will be asked to provide.
.It req_output_size
The desired maximum size for tokens emitted by
.Xr gss_wrap 3 .
.It max_input_size
The maximum input message size that may be presented to
.Xr gss_wrap 3
in order to guarantee that the emitted token shall
be no larger than
.Dv req_output_size
bytes.
.El
.Sh RETURN VALUES
.Bl -tag
.It GSS_S_COMPLETE
Successful completion.
.It GSS_S_NO_CONTEXT
The referenced context could not be accessed.
.It GSS_S_CONTEXT_EXPIRED
The context has expired.
.It GSS_S_BAD_QOP
The specified QOP is not supported by the mechanism.
.El
.Sh SEE ALSO
.Xr gss_wrap 3
.Sh STANDARDS
.Bl -tag
.It RFC 2743
Generic Security Service Application Program Interface Version 2, Update 1
.It RFC 2744
Generic Security Service API Version 2 : C-bindings
.\" .Sh HISTORY
.Sh HISTORY
The
.Nm
manual page example first appeared in
.Fx 7.0 .
.Sh AUTHORS
John Wray, Iris Associates