diff options
Diffstat (limited to 'ssh/gss.h')
| -rw-r--r-- | ssh/gss.h | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/ssh/gss.h b/ssh/gss.h new file mode 100644 index 00000000..c819d48b --- /dev/null +++ b/ssh/gss.h @@ -0,0 +1,217 @@ +#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*/ |