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

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

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