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#ifndef PUTTY_SSHGSS_H
#define PUTTY_SSHGSS_H
#include "putty.h"
#include "pgssapi.h"
#ifndef NO_GSSAPI
#define SSH2_GSS_OIDTYPE 0x06
typedef void *Ssh_gss_ctx;
typedef enum Ssh_gss_stat {
SSH_GSS_OK = 0,
SSH_GSS_S_CONTINUE_NEEDED,
SSH_GSS_NO_MEM,
SSH_GSS_BAD_HOST_NAME,
SSH_GSS_BAD_MIC,
SSH_GSS_NO_CREDS,
SSH_GSS_FAILURE
} Ssh_gss_stat;
#define SSH_GSS_S_COMPLETE SSH_GSS_OK
#define SSH_GSS_CLEAR_BUF(buf) do { \
(*buf).length = 0; \
(*buf).value = NULL; \
} while (0)
typedef gss_buffer_desc Ssh_gss_buf;
typedef gss_name_t Ssh_gss_name;
#define GSS_NO_EXPIRATION ((time_t)-1)
#define GSS_DEF_REKEY_MINS 2 /* Default minutes between GSS cache checks */
/* Functions, provided by either {windows,unix}/gss.c or gssc.c */
struct ssh_gss_library;
/*
* Prepare a collection of GSSAPI libraries for use in a single SSH
* connection. Returns a structure containing a list of libraries,
* with their ids (see struct ssh_gss_library below) filled in so
* that the client can go through them in the SSH user's preferred
* order.
*
* Must always return non-NULL. (Even if no libraries are available,
* it must return an empty structure.)
*
* The free function cleans up the structure, and its associated
* libraries (if any).
*/
struct ssh_gss_liblist {
struct ssh_gss_library *libraries;
int nlibraries;
};
struct ssh_gss_liblist *ssh_gss_setup(Conf *conf);
void ssh_gss_cleanup(struct ssh_gss_liblist *list);
/*
* Fills in buf with a string describing the GSSAPI mechanism in
* use. buf->data is not dynamically allocated.
*/
typedef Ssh_gss_stat (*t_ssh_gss_indicate_mech)(struct ssh_gss_library *lib,
Ssh_gss_buf *buf);
/*
* Converts a name such as a hostname into a GSSAPI internal form,
* which is placed in "out". The result should be freed by
* ssh_gss_release_name().
*/
typedef Ssh_gss_stat (*t_ssh_gss_import_name)(struct ssh_gss_library *lib,
char *in, Ssh_gss_name *out);
/*
* Frees the contents of an Ssh_gss_name structure filled in by
* ssh_gss_import_name().
*/
typedef Ssh_gss_stat (*t_ssh_gss_release_name)(struct ssh_gss_library *lib,
Ssh_gss_name *name);
/*
* The main GSSAPI security context setup function. The "out"
* parameter will need to be freed by ssh_gss_free_tok.
*/
typedef Ssh_gss_stat (*t_ssh_gss_init_sec_context)
(struct ssh_gss_library *lib,
Ssh_gss_ctx *ctx, Ssh_gss_name name, int delegate,
Ssh_gss_buf *in, Ssh_gss_buf *out, time_t *expiry,
unsigned long *lifetime);
/*
* Frees the contents of an Ssh_gss_buf filled in by
* ssh_gss_init_sec_context(). Do not accidentally call this on
* something filled in by ssh_gss_get_mic() (which requires a
* different free function) or something filled in by any other
* way.
*/
typedef Ssh_gss_stat (*t_ssh_gss_free_tok)(struct ssh_gss_library *lib,
Ssh_gss_buf *);
/*
* Acquires the credentials to perform authentication in the first
* place. Needs to be freed by ssh_gss_release_cred().
*/
typedef Ssh_gss_stat (*t_ssh_gss_acquire_cred)(struct ssh_gss_library *lib,
Ssh_gss_ctx *,
time_t *expiry);
/*
* Frees the contents of an Ssh_gss_ctx filled in by
* ssh_gss_acquire_cred().
*/
typedef Ssh_gss_stat (*t_ssh_gss_release_cred)(struct ssh_gss_library *lib,
Ssh_gss_ctx *);
/*
* Gets a MIC for some input data. "out" needs to be freed by
* ssh_gss_free_mic().
*/
typedef Ssh_gss_stat (*t_ssh_gss_get_mic)(struct ssh_gss_library *lib,
Ssh_gss_ctx ctx, Ssh_gss_buf *in,
Ssh_gss_buf *out);
/*
* Validates an input MIC for some input data.
*/
typedef Ssh_gss_stat (*t_ssh_gss_verify_mic)(struct ssh_gss_library *lib,
Ssh_gss_ctx ctx,
Ssh_gss_buf *in_data,
Ssh_gss_buf *in_mic);
/*
* Frees the contents of an Ssh_gss_buf filled in by
* ssh_gss_get_mic(). Do not accidentally call this on something
* filled in by ssh_gss_init_sec_context() (which requires a
* different free function) or something filled in by any other
* way.
*/
typedef Ssh_gss_stat (*t_ssh_gss_free_mic)(struct ssh_gss_library *lib,
Ssh_gss_buf *);
/*
* Return an error message after authentication failed. The
* message string is returned in "buf", with buf->len giving the
* number of characters of printable message text and buf->data
* containing one more character which is a trailing NUL.
* buf->data should be manually freed by the caller.
*/
typedef Ssh_gss_stat (*t_ssh_gss_display_status)(struct ssh_gss_library *lib,
Ssh_gss_ctx, Ssh_gss_buf *buf);
struct ssh_gss_library {
/*
* Identifying number in the enumeration used by the
* configuration code to specify a preference order.
*/
int id;
/*
* Filled in at initialisation time, if there's anything
* interesting to say about how GSSAPI was initialised (e.g.
* which of a number of alternative libraries was used).
*/
const char *gsslogmsg;
/*
* Function pointers implementing the SSH wrapper layer on top
* of GSSAPI. (Defined in sshgssc, typically, though Windows
* provides an alternative layer to sit on top of the annoyingly
* different SSPI.)
*/
t_ssh_gss_indicate_mech indicate_mech;
t_ssh_gss_import_name import_name;
t_ssh_gss_release_name release_name;
t_ssh_gss_init_sec_context init_sec_context;
t_ssh_gss_free_tok free_tok;
t_ssh_gss_acquire_cred acquire_cred;
t_ssh_gss_release_cred release_cred;
t_ssh_gss_get_mic get_mic;
t_ssh_gss_verify_mic verify_mic;
t_ssh_gss_free_mic free_mic;
t_ssh_gss_display_status display_status;
/*
* Additional data for the wrapper layers.
*/
union {
struct gssapi_functions gssapi;
/*
* The SSPI wrappers don't need to store their Windows API
* function pointers in this structure, because there can't
* be more than one set of them available.
*/
} u;
/*
* Wrapper layers will often also need to store a library handle
* of some sort for cleanup time.
*/
void *handle;
};
/*
* State that has to be shared between all GSSAPI-using parts of the
* same SSH connection, in particular between GSS key exchange and the
* subsequent trivial userauth method that reuses its output.
*/
struct ssh_connection_shared_gss_state {
struct ssh_gss_liblist *libs;
struct ssh_gss_library *lib;
Ssh_gss_name srv_name;
Ssh_gss_ctx ctx;
};
#endif /* NO_GSSAPI */
#endif /*PUTTY_SSHGSS_H*/
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