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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* tests/conccache.c - ccache concurrent get_creds/refresh test program */
/*
* Copyright (C) 2021 by the Massachusetts Institute of Technology.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
* COPYRIGHT HOLDER 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.
*/
/*
* Usage: conccache ccname clientprinc serverprinc
*
* This program spawns two subprocesses. One repeatedly runs
* krb5_get_credentials() on ccname, and the other repeatedly refreshes ccname
* from the default keytab. If either subprocess fails, the program exits with
* status 1. The goal is to expose time windows where cache refreshes cause
* get_cred operations to fail.
*/
#include "k5-platform.h"
#include <sys/types.h>
#include <sys/wait.h>
#include <pthread.h>
#include <krb5.h>
/* Run this many iterations of each operation. */
static const int iterations = 200;
/* Saved command-line arguments. */
static const char *ccname, *server_name, *client_name;
static void
check(krb5_error_code code)
{
if (code)
abort();
}
static krb5_boolean
get_cred(krb5_context context)
{
krb5_error_code ret;
krb5_ccache cc;
krb5_principal client, server;
krb5_creds mcred, *cred;
check(krb5_cc_resolve(context, ccname, &cc));
check(krb5_parse_name(context, client_name, &client));
check(krb5_parse_name(context, server_name, &server));
memset(&mcred, 0, sizeof(mcred));
mcred.client = client;
mcred.server = server;
ret = krb5_get_credentials(context, 0, cc, &mcred, &cred);
krb5_free_creds(context, cred);
krb5_free_principal(context, client);
krb5_free_principal(context, server);
krb5_cc_close(context, cc);
return ret == 0;
}
static krb5_boolean
refresh_cache(krb5_context context)
{
krb5_error_code ret;
krb5_ccache cc;
krb5_principal client;
krb5_get_init_creds_opt *opt;
krb5_creds cred;
check(krb5_cc_resolve(context, ccname, &cc));
check(krb5_parse_name(context, client_name, &client));
check(krb5_get_init_creds_opt_alloc(context, &opt));
check(krb5_get_init_creds_opt_set_out_ccache(context, opt, cc));
ret = krb5_get_init_creds_keytab(context, &cred, client, NULL, 0, NULL,
opt);
krb5_get_init_creds_opt_free(context, opt);
krb5_free_cred_contents(context, &cred);
krb5_free_principal(context, client);
krb5_cc_close(context, cc);
return ret == 0;
}
static pid_t
spawn_cred_subprocess()
{
krb5_context context;
pid_t pid;
int i;
pid = fork();
assert(pid >= 0);
if (pid > 0)
return pid;
check(krb5_init_context(&context));
for (i = 0; i < iterations; i++) {
if (!get_cred(context)) {
fprintf(stderr, "cred worker failed after %d successes\n", i);
exit(1);
}
}
krb5_free_context(context);
exit(0);
}
static pid_t
spawn_refresh_subprocess()
{
krb5_context context;
pid_t pid;
int i;
pid = fork();
assert(pid >= 0);
if (pid > 0)
return pid;
check(krb5_init_context(&context));
for (i = 0; i < iterations; i++) {
if (!refresh_cache(context)) {
fprintf(stderr, "refresh worker failed after %d successes\n", i);
exit(1);
}
}
krb5_free_context(context);
exit(0);
}
int
main(int argc, char *argv[])
{
krb5_context context;
pid_t cred_pid, refresh_pid, pid;
int cstatus, rstatus;
assert(argc == 4);
ccname = argv[1];
client_name = argv[2];
server_name = argv[3];
/* Begin with an initialized cache. */
check(krb5_init_context(&context));
refresh_cache(context);
krb5_free_context(context);
cred_pid = spawn_cred_subprocess();
refresh_pid = spawn_refresh_subprocess();
pid = waitpid(cred_pid, &cstatus, 0);
if (pid == -1)
abort();
pid = waitpid(refresh_pid, &rstatus, 0);
if (pid == -1)
abort();
if (!WIFEXITED(cstatus) || WEXITSTATUS(cstatus) != 0)
return 1;
if (!WIFEXITED(rstatus) || WEXITSTATUS(rstatus) != 0)
return 1;
return 0;
}
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