git.distorted.org.uk Git - u/mdw/putty/blob - sshgss.h

   1 #ifndef PUTTY_SSHGSS_H
   2 #define PUTTY_SSHGSS_H
   3 #include "putty.h"
   4 #include "pgssapi.h"
   5
   6 #ifndef NO_GSSAPI
   7
   8 #define SSH2_GSS_OIDTYPE 0x06
   9 typedef void *Ssh_gss_ctx;
  10
  11 typedef enum Ssh_gss_stat {
  12     SSH_GSS_OK = 0,
  13     SSH_GSS_S_CONTINUE_NEEDED,
  14     SSH_GSS_NO_MEM,
  15     SSH_GSS_BAD_HOST_NAME,
  16     SSH_GSS_FAILURE
  17 } Ssh_gss_stat;
  18
  19 #define SSH_GSS_S_COMPLETE SSH_GSS_OK
  20
  21 #define SSH_GSS_CLEAR_BUF(buf) do {             \
  22     (*buf).length = 0;                          \
  23     (*buf).value = NULL;                                \
  24 } while (0)
  25
  26 typedef gss_buffer_desc Ssh_gss_buf;
  27 typedef gss_name_t Ssh_gss_name;
  28
  29 /* Functions, provided by either wingss.c or sshgssc.c */
  30
  31 struct ssh_gss_library;
  32
  33 /*
  34  * Do startup-time initialisation for using GSSAPI. This should
  35  * correctly initialise the array of struct ssh_gss_library declared
  36  * below.
  37  *
  38  * Must be callable multiple times (since the most convenient place
  39  * to call it _from_ is the ssh.c setup code), and should harmlessly
  40  * return success if already initialised.
  41  */
  42 void ssh_gss_init(void);
  43
  44 /*
  45  * Fills in buf with a string describing the GSSAPI mechanism in
  46  * use. buf->data is not dynamically allocated.
  47  */
  48 typedef Ssh_gss_stat (*t_ssh_gss_indicate_mech)(struct ssh_gss_library *lib,
  49                                                 Ssh_gss_buf *buf);
  50
  51 /*
  52  * Converts a name such as a hostname into a GSSAPI internal form,
  53  * which is placed in "out". The result should be freed by
  54  * ssh_gss_release_name().
  55  */
  56 typedef Ssh_gss_stat (*t_ssh_gss_import_name)(struct ssh_gss_library *lib,
  57                                               char *in, Ssh_gss_name *out);
  58
  59 /*
  60  * Frees the contents of an Ssh_gss_name structure filled in by
  61  * ssh_gss_import_name().
  62  */
  63 typedef Ssh_gss_stat (*t_ssh_gss_release_name)(struct ssh_gss_library *lib,
  64                                                Ssh_gss_name *name);
  65
  66 /*
  67  * The main GSSAPI security context setup function. The "out"
  68  * parameter will need to be freed by ssh_gss_free_tok.
  69  */
  70 typedef Ssh_gss_stat (*t_ssh_gss_init_sec_context)
  71     (struct ssh_gss_library *lib,
  72      Ssh_gss_ctx *ctx, Ssh_gss_name name, int delegate,
  73      Ssh_gss_buf *in, Ssh_gss_buf *out);
  74
  75 /*
  76  * Frees the contents of an Ssh_gss_buf filled in by
  77  * ssh_gss_init_sec_context(). Do not accidentally call this on
  78  * something filled in by ssh_gss_get_mic() (which requires a
  79  * different free function) or something filled in by any other
  80  * way.
  81  */
  82 typedef Ssh_gss_stat (*t_ssh_gss_free_tok)(struct ssh_gss_library *lib,
  83                                            Ssh_gss_buf *);
  84
  85 /*
  86  * Acquires the credentials to perform authentication in the first
  87  * place. Needs to be freed by ssh_gss_release_cred().
  88  */
  89 typedef Ssh_gss_stat (*t_ssh_gss_acquire_cred)(struct ssh_gss_library *lib,
  90                                                Ssh_gss_ctx *);
  91
  92 /*
  93  * Frees the contents of an Ssh_gss_ctx filled in by
  94  * ssh_gss_acquire_cred().
  95  */
  96 typedef Ssh_gss_stat (*t_ssh_gss_release_cred)(struct ssh_gss_library *lib,
  97                                                Ssh_gss_ctx *);
  98
  99 /*
 100  * Gets a MIC for some input data. "out" needs to be freed by
 101  * ssh_gss_free_mic().
 102  */
 103 typedef Ssh_gss_stat (*t_ssh_gss_get_mic)(struct ssh_gss_library *lib,
 104                                           Ssh_gss_ctx ctx, Ssh_gss_buf *in,
 105                  Ssh_gss_buf *out);
 106
 107 /*
 108  * Frees the contents of an Ssh_gss_buf filled in by
 109  * ssh_gss_get_mic(). Do not accidentally call this on something
 110  * filled in by ssh_gss_init_sec_context() (which requires a
 111  * different free function) or something filled in by any other
 112  * way.
 113  */
 114 typedef Ssh_gss_stat (*t_ssh_gss_free_mic)(struct ssh_gss_library *lib,
 115                                            Ssh_gss_buf *);
 116
 117 /*
 118  * Return an error message after authentication failed. The
 119  * message string is returned in "buf", with buf->len giving the
 120  * number of characters of printable message text and buf->data
 121  * containing one more character which is a trailing NUL.
 122  * buf->data should be manually freed by the caller.
 123  */
 124 typedef Ssh_gss_stat (*t_ssh_gss_display_status)(struct ssh_gss_library *lib,
 125                                                  Ssh_gss_ctx, Ssh_gss_buf *buf);
 126
 127 struct ssh_gss_library {
 128     /*
 129      * Identifying number in the enumeration used by the
 130      * configuration code to specify a preference order.
 131      */
 132     int id;
 133
 134     /*
 135      * Filled in at initialisation time, if there's anything
 136      * interesting to say about how GSSAPI was initialised (e.g.
 137      * which of a number of alternative libraries was used).
 138      */
 139     const char *gsslogmsg;
 140
 141     /*
 142      * Function pointers implementing the SSH wrapper layer on top
 143      * of GSSAPI. (Defined in sshgssc, typically, though Windows
 144      * provides an alternative layer to sit on top of the annoyingly
 145      * different SSPI.)
 146      */
 147     t_ssh_gss_indicate_mech indicate_mech;
 148     t_ssh_gss_import_name import_name;
 149     t_ssh_gss_release_name release_name;
 150     t_ssh_gss_init_sec_context init_sec_context;
 151     t_ssh_gss_free_tok free_tok;
 152     t_ssh_gss_acquire_cred acquire_cred;
 153     t_ssh_gss_release_cred release_cred;
 154     t_ssh_gss_get_mic get_mic;
 155     t_ssh_gss_free_mic free_mic;
 156     t_ssh_gss_display_status display_status;
 157
 158     /*
 159      * Additional data for the wrapper layers.
 160      */
 161     union {
 162         struct gssapi_functions gssapi;
 163         /*
 164          * The SSPI wrappers don't need to store their Windows API
 165          * function pointers in this structure, because there can't
 166          * be more than one set of them available.
 167          */
 168     } u;
 169 };
 170
 171 extern struct ssh_gss_library ssh_gss_libraries[];
 172 extern int n_ssh_gss_libraries;
 173
 174 #endif /* NO_GSSAPI */
 175
 176 #endif /*PUTTY_SSHGSS_H*/