gss_unwrap, gss_unseal(3)	Convert a message previously protected by gss_wrap 3 back to a usable form
gss_unseal, gss_unwrap(3)	Convert a message previously protected by gss_wrap 3 back to a usable form

NAME

gss_unwrap, gss_unseal — Convert a message previously protected by gss_wrap(3) back to a usable form

SYNOPSIS

#include <gssapi/gssapi.h>

OM_uint32
gss_unwrap(OM_uint32 *minor_status, const gss_ctx_id_t context_handle, const gss_buffer_t input_message_buffer, gss_buffer_t output_message_buffer, int *conf_state, gss_qop_t *qop_state);

OM_uint32
gss_unseal(OM_uint32 *minor_status, gss_ctx_id_t context_handle, gss_buffer_t input_message_buffer, gss_buffer_t output_message_buffer, int *conf_state, gss_qop_t *qop_state);

DESCRIPTION

Converts a message previously protected by gss_wrap(3) back to a usable form, verifying the embedded MIC. The conf_state parameter indicates whether the message was encrypted; the qop_state parameter indicates the strength of protection that was used to provide the confidentiality and integrity services.

Since some application-level protocols may wish to use tokens emitted by gss_wrap(3) to provide "secure framing", implementations must support the wrapping and unwrapping of zero-length messages.

The gss_unseal() routine is an obsolete variant of gss_unwrap(). 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 arrived.

input_message_buffer

Protected message.

output_message_buffer

Buffer to receive unwrapped message. Storage associated with this buffer must be freed by the application after use with a call to gss_release_buffer(3).

conf_state

Non-zero: Confidentiality and integrity protection were used.
Zero: Integrity service only was used.

Specify NULL if not required.

qop_state

Quality of protection provided. Specify NULL if not required.

RETURN VALUES

GSS_S_COMPLETE: Successful completion.
GSS_S_DEFECTIVE_TOKEN: The token failed consistency checks.
GSS_S_BAD_SIG: The MIC was incorrect
GSS_S_DUPLICATE_TOKEN: The token was valid, and contained a correct MIC for the message, but it had already been processed.
GSS_S_OLD_TOKEN: The token was valid, and contained a correct MIC for the message, but it is too old to check for duplication.
GSS_S_UNSEQ_TOKEN: The token was valid, and contained a correct MIC for the message, but has been verified out of sequence; a later token has already been received.
GSS_S_GAP_TOKEN: The token was valid, and contained a correct MIC for the message, but has been verified out of sequence; an earlier expected token has not yet been received.
GSS_S_CONTEXT_EXPIRED: The context has already expired.
GSS_S_NO_CONTEXT: The context_handle parameter did not identify a valid context.

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_unwrap function first appeared in FreeBSD 7.0.

AUTHORS

John Wray, Iris Associates

COPYRIGHT

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