unix/uxgss.c

   1 #include "putty.h"
   2 #ifndef NO_GSSAPI
   3 #include "pgssapi.h"
   4 #include "sshgss.h"
   5 #include "sshgssc.h"
   6
   7 /* Unix code to set up the GSSAPI library list. */
   8
   9 #if !defined NO_LIBDL && !defined NO_GSSAPI
  10
  11 const int ngsslibs = 4;
  12 const char *const gsslibnames[4] = {
  13     "libgssapi (Heimdal)",
  14     "libgssapi_krb5 (MIT Kerberos)",
  15     "libgss (Sun)",
  16     "User-specified GSSAPI library",
  17 };
  18 const struct keyvalwhere gsslibkeywords[] = {
  19     { "libgssapi", 0, -1, -1 },
  20     { "libgssapi_krb5", 1, -1, -1 },
  21     { "libgss", 2, -1, -1 },
  22     { "custom", 3, -1, -1 },
  23 };
  24
  25 /*
  26  * Run-time binding against a choice of GSSAPI implementations. We
  27  * try loading several libraries, and produce an entry in
  28  * ssh_gss_libraries[] for each one.
  29  */
  30
  31 static void gss_init(struct ssh_gss_library *lib, void *dlhandle,
  32                      int id, const char *msg)
  33 {
  34     lib->id = id;
  35     lib->gsslogmsg = msg;
  36     lib->handle = dlhandle;
  37
  38 #define BIND_GSS_FN(name) \
  39     lib->u.gssapi.name = (t_gss_##name) dlsym(dlhandle, "gss_" #name)
  40
  41     BIND_GSS_FN(delete_sec_context);
  42     BIND_GSS_FN(display_status);
  43     BIND_GSS_FN(get_mic);
  44     BIND_GSS_FN(import_name);
  45     BIND_GSS_FN(init_sec_context);
  46     BIND_GSS_FN(release_buffer);
  47     BIND_GSS_FN(release_cred);
  48     BIND_GSS_FN(release_name);
  49
  50 #undef BIND_GSS_FN
  51
  52     ssh_gssapi_bind_fns(lib);
  53 }
  54
  55 /* Dynamically load gssapi libs. */
  56 struct ssh_gss_liblist *ssh_gss_setup(const Config *cfg)
  57 {
  58     void *gsslib;
  59     struct ssh_gss_liblist *list = snew(struct ssh_gss_liblist);
  60
  61     list->libraries = snewn(4, struct ssh_gss_library);
  62     list->nlibraries = 0;
  63
  64     /* Heimdal's GSSAPI Library */
  65     if ((gsslib = dlopen("libgssapi.so.2", RTLD_LAZY)) != NULL)
  66         gss_init(&list->libraries[list->nlibraries++], gsslib,
  67                  0, "Using GSSAPI from libgssapi.so.2");
  68
  69     /* MIT Kerberos's GSSAPI Library */
  70     if ((gsslib = dlopen("libgssapi_krb5.so.2", RTLD_LAZY)) != NULL)
  71         gss_init(&list->libraries[list->nlibraries++], gsslib,
  72                  1, "Using GSSAPI from libgssapi_krb5.so.2");
  73
  74     /* Sun's GSSAPI Library */
  75     if ((gsslib = dlopen("libgss.so.1", RTLD_LAZY)) != NULL)
  76         gss_init(&list->libraries[list->nlibraries++], gsslib,
  77                  2, "Using GSSAPI from libgss.so.1");
  78
  79     /* User-specified GSSAPI library */
  80     if (cfg->ssh_gss_custom.path[0] &&
  81         (gsslib = dlopen(cfg->ssh_gss_custom.path, RTLD_LAZY)) != NULL)
  82         gss_init(&list->libraries[list->nlibraries++], gsslib,
  83                  3, dupprintf("Using GSSAPI from user-specified"
  84                               " library '%s'", cfg->ssh_gss_custom.path));
  85
  86     return list;
  87 }
  88
  89 void ssh_gss_cleanup(struct ssh_gss_liblist *list)
  90 {
  91     int i;
  92
  93     /*
  94      * dlopen and dlclose are defined to employ reference counting
  95      * in the case where the same library is repeatedly dlopened, so
  96      * even in a multiple-sessions-per-process context it's safe to
  97      * naively dlclose everything here without worrying about
  98      * destroying it under the feet of another SSH instance still
  99      * using it.
 100      */
 101     for (i = 0; i < list->nlibraries; i++) {
 102         dlclose(list->libraries[i].handle);
 103         if (list->libraries[i].id == 3) {
 104             /* The 'custom' id involves a dynamically allocated message.
 105              * Note that we must cast away the 'const' to free it. */
 106             sfree((char *)list->libraries[i].gsslogmsg);
 107         }
 108     }
 109     sfree(list->libraries);
 110     sfree(list);
 111 }
 112
 113 #elif !defined NO_GSSAPI
 114
 115 const int ngsslibs = 1;
 116 const char *const gsslibnames[1] = {
 117     "static",
 118 };
 119 const struct keyvalwhere gsslibkeywords[] = {
 120     { "static", 0, -1, -1 },
 121 };
 122
 123 /*
 124  * Link-time binding against GSSAPI. Here we just construct a single
 125  * library structure containing pointers to the functions we linked
 126  * against.
 127  */
 128
 129 #include <gssapi/gssapi.h>
 130
 131 /* Dynamically load gssapi libs. */
 132 struct ssh_gss_liblist *ssh_gss_setup(const Config *cfg)
 133 {
 134     struct ssh_gss_liblist *list = snew(struct ssh_gss_liblist);
 135
 136     list->libraries = snew(struct ssh_gss_library);
 137     list->nlibraries = 1;
 138
 139     list->libraries[0].gsslogmsg = "Using statically linked GSSAPI";
 140
 141 #define BIND_GSS_FN(name) \
 142     list->libraries[0].u.gssapi.name = (t_gss_##name) gss_##name
 143
 144     BIND_GSS_FN(delete_sec_context);
 145     BIND_GSS_FN(display_status);
 146     BIND_GSS_FN(get_mic);
 147     BIND_GSS_FN(import_name);
 148     BIND_GSS_FN(init_sec_context);
 149     BIND_GSS_FN(release_buffer);
 150     BIND_GSS_FN(release_cred);
 151     BIND_GSS_FN(release_name);
 152
 153 #undef BIND_GSS_FN
 154
 155     ssh_gssapi_bind_fns(&list->libraries[0]);
 156
 157     return list;
 158 }
 159
 160 void ssh_gss_cleanup(struct ssh_gss_liblist *list)
 161 {
 162     sfree(list->libraries);
 163     sfree(list);
 164 }
 165
 166 #endif /* NO_LIBDL */
 167
 168 #endif /* NO_GSSAPI */