GSS_GET_MIC(3)

NAME
gss_get_mic, gss_sign - Calculate a cryptographic message integrity code (MIC) for a message; integrity service

SYNOPSIS
#include <gssapi/gssapi.h>
OM_uint32
gss_get_mic(OM_uint32 *minor_status, const gss_ctx_id_t context_handle, gss_qop_t qop_req, const gss_buffer_t message_buffer, gss_buffer_t msg_token);
OM_uint32
gss_sign(OM_uint32 *minor_status, const gss_ctx_id_t context_handle, gss_qop_t qop_req, gss_buffer_t message_buffer, gss_buffer_t msg_token);

DESCRIPTION
Generates a cryptographic MIC for the supplied message, and places the MIC in a token for transfer to the peer application. The qop_req parameter allows a choice between several cryptographic algorithms, if supported by the chosen mechanism.

Since some application-level protocols may wish to use tokens emitted by gss_wrap() to provide "secure framing", implementations must support derivation of MICs from zero-length messages.

The gss_sign() routine is an obsolete variant of gss_get_mic(). It is provided for backwards compatibility with applications using the GSS-API V1 interface. A distinct entrypoint (as opposed to #define) is provided, both to allow GSS-API V1 applications to link and to retain the slight parameter type differences between the obsolete versions of this routine and its current form.

PARAMETERS

minor_status
    Mechanism specific status code.

context_handle
    Identifies the context on which the message will be sent.

qop_req
    Specifies requested quality of protection. Callers are encouraged, on portability grounds, to accept the default quality of protection offered by the chosen mechanism, which may be requested by specifying GSS_C_QOP_DEFAULT for this parameter. If an unsupported protection strength is requested, gss_get_mic() will return a major_status of GSS_S_BAD_QOP.

message_buffer
    Message to be protected.

msg_token
    Buffer to receive token. The application must free storage associated with this buffer after use with a call to gss_release_buffer().

RETURN VALUES

GSS_S_COMPLETE
    Successful completion

GSS_S_CONTEXT_EXPIRED
    The context has already expired

GSS_S_NO_CONTEXT
    The context_handle parameter did not identify a valid context

GSS_S_BAD_QOP
    The specified QOP is not supported by the mechanism

SEE ALSO
gss_wrap(3), gss_release_buffer(3)

STANDARDS

RFC 2743
    Generic Security Service Application Program Interface Version 2, Update 1

RFC 2744
    Generic Security Service API Version 2 : C-bindings

HISTORY
The gss_get_mic function first appeared in FreeBSD 7.0.

AUTHORS
John Wray, Iris Associates

COPYRIGHT
Copyright (C) The Internet Society (2000). All Rights Reserved.

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