Files
heimdal/lib/krb5/aname_to_localname.c
Roland C. Dowdeswell 2c5ec44d39 Look for auth_to_local in the default realm's realm section...
...rather than the authenticated principal's realm section.  We do
this both to maintain compatibility with MIT and because it makes
more sense.  We should likely also fix the auth_to_local_names as
cursory inspection reveals that it has the same incompatibility.
2012-04-19 23:43:12 +01:00

452 lines
12 KiB
C

/*
* Copyright (c) 1997 - 1999, 2002 - 2003 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb5_locl.h"
#include "an2ln_plugin.h"
#include "db_plugin.h"
/* Default plugin (DB using binary search of sorted text file) follows */
static krb5_error_code KRB5_LIB_CALL an2ln_def_plug_init(krb5_context, void **);
static void KRB5_LIB_CALL an2ln_def_plug_fini(void *);
static krb5_error_code KRB5_LIB_CALL an2ln_def_plug_an2ln(void *, krb5_context, const char *,
krb5_const_principal, set_result_f,
void *);
static krb5plugin_an2ln_ftable an2ln_def_plug = {
0,
an2ln_def_plug_init,
an2ln_def_plug_fini,
an2ln_def_plug_an2ln,
};
/* Plugin engine code follows */
struct plctx {
krb5_const_principal aname;
heim_string_t luser;
const char *rule;
};
static krb5_error_code KRB5_LIB_CALL
set_res(void *userctx, const char *res)
{
struct plctx *plctx = userctx;
plctx->luser = heim_string_create(res);
if (plctx->luser == NULL)
return ENOMEM;
return 0;
}
static krb5_error_code KRB5_LIB_CALL
plcallback(krb5_context context,
const void *plug, void *plugctx, void *userctx)
{
const krb5plugin_an2ln_ftable *locate = plug;
struct plctx *plctx = userctx;
if (plctx->luser)
return 0;
return locate->an2ln(plugctx, context, plctx->rule, plctx->aname, set_res, plctx);
}
static krb5_error_code
an2ln_plugin(krb5_context context, const char *rule, krb5_const_principal aname,
size_t lnsize, char *lname)
{
krb5_error_code ret;
struct plctx ctx;
ctx.rule = rule;
ctx.aname = aname;
ctx.luser = NULL;
/*
* Order of plugin invocation is non-deterministic, but there should
* really be no more than one plugin that can handle any given kind
* rule, so the effect should be deterministic anyways.
*/
ret = _krb5_plugin_run_f(context, "krb5", KRB5_PLUGIN_AN2LN,
KRB5_PLUGIN_AN2LN_VERSION_0, 0, &ctx, plcallback);
if (ret != 0) {
heim_release(ctx.luser);
return ret;
}
if (ctx.luser == NULL)
return KRB5_PLUGIN_NO_HANDLE;
if (strlcpy(lname, heim_string_get_utf8(ctx.luser), lnsize) >= lnsize)
ret = KRB5_CONFIG_NOTENUFSPACE;
heim_release(ctx.luser);
return ret;
}
static void
reg_def_plugins_once(void *ctx)
{
krb5_error_code ret;
krb5_context context = ctx;
ret = krb5_plugin_register(context, PLUGIN_TYPE_DATA,
KRB5_PLUGIN_AN2LN, &an2ln_def_plug);
}
static int
princ_realm_is_default(krb5_context context,
krb5_const_principal aname)
{
krb5_error_code ret;
krb5_realm *lrealms = NULL;
krb5_realm *r;
int valid;
ret = krb5_get_default_realms(context, &lrealms);
if (ret)
return 0;
valid = 0;
for (r = lrealms; *r != NULL; ++r) {
if (strcmp (*r, aname->realm) == 0) {
valid = 1;
break;
}
}
krb5_free_host_realm (context, lrealms);
return valid;
}
/*
* This function implements MIT's auth_to_local_names configuration for
* configuration compatibility. Specifically:
*
* [realms]
* <realm-name> = {
* auth_to_local_names = {
* <unparsed-principal-name> = <username>
* }
* }
*
* If multiple usernames are configured then the last one is taken.
*
* The configuration can only be expected to hold a relatively small
* number of mappings. For lots of mappings use a DB.
*/
static krb5_error_code
an2ln_local_names(krb5_context context,
krb5_const_principal aname,
size_t lnsize,
char *lname)
{
krb5_error_code ret;
char *unparsed;
char **values;
char *res;
size_t i;
if (!princ_realm_is_default(context, aname))
return KRB5_PLUGIN_NO_HANDLE;
ret = krb5_unparse_name_flags(context, aname,
KRB5_PRINCIPAL_UNPARSE_NO_REALM,
&unparsed);
if (ret)
return ret;
ret = KRB5_PLUGIN_NO_HANDLE;
values = krb5_config_get_strings(context, NULL, "realms", aname->realm,
"auth_to_local_names", unparsed, NULL);
free(unparsed);
if (!values)
return ret;
/* Take the last value, just like MIT */
for (res = NULL, i = 0; values[i]; i++)
res = values[i];
if (res) {
ret = 0;
if (strlcpy(lname, res, lnsize) >= lnsize)
ret = KRB5_CONFIG_NOTENUFSPACE;
if (!*res || strcmp(res, ":") == 0)
ret = KRB5_NO_LOCALNAME;
}
krb5_config_free_strings(values);
return ret;
}
/*
* Heimdal's default aname2lname mapping.
*/
static krb5_error_code
an2ln_default(krb5_context context,
char *rule,
krb5_const_principal aname,
size_t lnsize, char *lname)
{
krb5_error_code ret;
const char *res;
int root_princs_ok;
if (strcmp(rule, "NONE") == 0)
return KRB5_NO_LOCALNAME;
if (strcmp(rule, "DEFAULT") == 0)
root_princs_ok = 0;
else if (strcmp(rule, "HEIMDAL_DEFAULT") == 0)
root_princs_ok = 1;
else
return KRB5_PLUGIN_NO_HANDLE;
if (!princ_realm_is_default(context, aname))
return KRB5_PLUGIN_NO_HANDLE;
if (aname->name.name_string.len == 1) {
/*
* One component principal names in default realm -> the one
* component is the username.
*/
res = aname->name.name_string.val[0];
} else if (root_princs_ok && aname->name.name_string.len == 2 &&
strcmp (aname->name.name_string.val[1], "root") == 0) {
/*
* Two-component principal names in default realm where the
* first component is "root" -> root IFF the principal is in
* root's .k5login (or whatever krb5_kuserok() does).
*/
krb5_principal rootprinc;
krb5_boolean userok;
res = "root";
ret = krb5_copy_principal(context, aname, &rootprinc);
if (ret)
return ret;
userok = _krb5_kuserok(context, rootprinc, res, FALSE);
krb5_free_principal(context, rootprinc);
if (!userok)
return KRB5_NO_LOCALNAME;
} else {
return KRB5_PLUGIN_NO_HANDLE;
}
if (strlcpy(lname, res, lnsize) >= lnsize)
return KRB5_CONFIG_NOTENUFSPACE;
return 0;
}
/**
* Map a principal name to a local username.
*
* Returns 0 on success, KRB5_NO_LOCALNAME if no mapping was found, or
* some Kerberos or system error.
*
* Inputs:
*
* @param context A krb5_context
* @param aname A principal name
* @param lnsize The size of the buffer into which the username will be written
* @param lname The buffer into which the username will be written
*
* @ingroup krb5_support
*/
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_aname_to_localname(krb5_context context,
krb5_const_principal aname,
size_t lnsize,
char *lname)
{
static heim_base_once_t reg_def_plugins = HEIM_BASE_ONCE_INIT;
krb5_error_code ret;
krb5_realm realm;
size_t i;
char **rules = NULL;
char *rule;
if (lnsize)
lname[0] = '\0';
heim_base_once_f(&reg_def_plugins, context, reg_def_plugins_once);
/* Try MIT's auth_to_local_names config first */
ret = an2ln_local_names(context, aname, lnsize, lname);
if (ret != KRB5_PLUGIN_NO_HANDLE)
return ret;
ret = krb5_get_default_realm(context, &realm);
if (ret)
return ret;
rules = krb5_config_get_strings(context, NULL, "realms", realm,
"auth_to_local", NULL);
krb5_xfree(realm);
if (!rules) {
/* Heimdal's default rule */
ret = an2ln_default(context, "HEIMDAL_DEFAULT", aname, lnsize, lname);
if (ret == KRB5_PLUGIN_NO_HANDLE)
return KRB5_NO_LOCALNAME;
return ret;
}
/*
* MIT rules.
*
* Note that RULEs and DBs only have white-list functionality,
* thus RULEs and DBs that we don't understand we simply ignore.
*
* This means that plugins that implement black-lists are
* dangerous: if a black-list plugin isn't found, the black-list
* won't be enforced. But black-lists are dangerous anyways.
*/
for (ret = KRB5_PLUGIN_NO_HANDLE, i = 0; rules[i]; i++) {
rule = rules[i];
/* Try NONE, DEFAULT, and HEIMDAL_DEFAULT rules */
ret = an2ln_default(context, rule, aname, lnsize, lname);
if (ret == KRB5_PLUGIN_NO_HANDLE)
/* Try DB, RULE, ... plugins */
ret = an2ln_plugin(context, rule, aname, lnsize, lname);
if (ret == 0 && lnsize && !lname[0])
continue; /* Success but no lname?! lies! */
else if (ret != KRB5_PLUGIN_NO_HANDLE)
break;
}
if (ret == KRB5_PLUGIN_NO_HANDLE) {
if (lnsize)
lname[0] = '\0';
ret = KRB5_NO_LOCALNAME;
}
krb5_config_free_strings(rules);
return ret;
}
static krb5_error_code KRB5_LIB_CALL
an2ln_def_plug_init(krb5_context context, void **ctx)
{
*ctx = NULL;
return 0;
}
static void KRB5_LIB_CALL
an2ln_def_plug_fini(void *ctx)
{
}
static heim_base_once_t sorted_text_db_init_once = HEIM_BASE_ONCE_INIT;
static void
sorted_text_db_init_f(void *arg)
{
(void) heim_db_register("sorted-text", NULL, &heim_sorted_text_file_dbtype);
}
static krb5_error_code KRB5_LIB_CALL
an2ln_def_plug_an2ln(void *plug_ctx, krb5_context context,
const char *rule,
krb5_const_principal aname,
set_result_f set_res_f, void *set_res_ctx)
{
krb5_error_code ret;
const char *an2ln_db_fname;
heim_db_t dbh = NULL;
heim_dict_t db_options;
heim_data_t k, v;
heim_error_t error;
char *unparsed = NULL;
char *value = NULL;
_krb5_load_db_plugins(context);
heim_base_once_f(&sorted_text_db_init_once, NULL, sorted_text_db_init_f);
if (strncmp(rule, "DB:", strlen("DB:") != 0))
return KRB5_PLUGIN_NO_HANDLE;
an2ln_db_fname = &rule[strlen("DB:")];
if (!*an2ln_db_fname)
return KRB5_PLUGIN_NO_HANDLE;
ret = krb5_unparse_name(context, aname, &unparsed);
if (ret)
return ret;
db_options = heim_dict_create(11);
if (db_options != NULL)
heim_dict_set_value(db_options, HSTR("read-only"),
heim_number_create(1));
dbh = heim_db_create(NULL, an2ln_db_fname, db_options, &error);
if (dbh == NULL) {
krb5_set_error_message(context, heim_error_get_code(error),
N_("Couldn't open aname2lname-text-db", ""));
ret = KRB5_PLUGIN_NO_HANDLE;
goto cleanup;
}
/* Binary search; file should be sorted (in C locale) */
k = heim_data_ref_create(unparsed, strlen(unparsed), NULL);
if (k == NULL)
return krb5_enomem(context);
v = heim_db_copy_value(dbh, NULL, k, &error);
heim_release(k);
if (v == NULL && error != NULL) {
krb5_set_error_message(context, heim_error_get_code(error),
N_("Lookup in aname2lname-text-db failed", ""));
ret = heim_error_get_code(error);
goto cleanup;
} else if (v == NULL) {
ret = KRB5_PLUGIN_NO_HANDLE;
goto cleanup;
} else {
/* found */
if (heim_data_get_length(v) == 0) {
krb5_set_error_message(context, ret,
N_("Principal mapped to empty username", ""));
ret = KRB5_NO_LOCALNAME;
goto cleanup;
}
ret = set_res_f(set_res_ctx, heim_data_get_ptr(v));
heim_release(v);
}
cleanup:
heim_release(dbh);
free(unparsed);
free(value);
return ret;
}