NAME

gss_export_sec_context —

Transfer a security context to another process

SYNOPSIS

#include <gssapi/gssapi.h>

OM_uint32
gss_export_sec_context(OM_uint32 *minor_status, gss_ctx_id_t *context_handle, gss_buffer_t interprocess_token);

DESCRIPTION

Provided to support the sharing of work between multiple processes. This routine will typically be used by the context-acceptor, in an application where a single process receives incoming connection requests and accepts security contexts over them, then passes the established context to one or more other processes for message exchange. gss_export_sec_context() deactivates the security context for the calling process and creates an interprocess token which, when passed to gss_import_sec_context() in another process, will re-activate the context in the second process. Only a single instantiation of a given context may be active at any one time; a subsequent attempt by a context exporter to access the exported security context will fail.

The implementation may constrain the set of processes by which the interprocess token may be imported, either as a function of local security policy, or as a result of implementation decisions. For example, some implementations may constrain contexts to be passed only between processes that run under the same account, or which are part of the same process group.

The interprocess token may contain security-sensitive information (for example cryptographic keys). While mechanisms are encouraged to either avoid placing such sensitive information within interprocess tokens, or to encrypt the token before returning it to the application, in a typical object-library GSS-API implementation this may not be possible. Thus the application must take care to protect the interprocess token, and ensure that any process to which the token is transferred is trustworthy.

If creation of the interprocess token is successful, the implementation shall deallocate all process-wide resources associated with the security context, and set the context_handle to GSS_C_NO_CONTEXT. In the event of an error that makes it impossible to complete the export of the security context, the implementation must not return an interprocess token, and should strive to leave the security context referenced by the context_handle parameter untouched. If this is impossible, it is permissible for the implementation to delete the security context, providing it also sets the context_handle parameter to GSS_C_NO_CONTEXT.

PARAMETERS

minor_status: Mechanism specific status code.
context_handle: Context handle identifying the context to transfer.
interprocess_token: Token to be transferred to target process. Storage associated with this token must be freed by the application after use with a call to gss_release_buffer().

RETURN VALUES

GSS_S_COMPLETE: Successful completion
GSS_S_CONTEXT_EXPIRED: The context has expired
GSS_S_NO_CONTEXT: The context was invalid
GSS_S_UNAVAILABLE: The operation is not supported

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_export_sec_context function first appeared in FreeBSD 7.0.

AUTHORS

John Wray, Iris Associates

COPYRIGHT

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