diff options
Diffstat (limited to 'lib/libpam/openpam_dynamic.c')
| -rw-r--r-- | lib/libpam/openpam_dynamic.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/lib/libpam/openpam_dynamic.c b/lib/libpam/openpam_dynamic.c new file mode 100644 index 0000000..1dfc1ac --- /dev/null +++ b/lib/libpam/openpam_dynamic.c @@ -0,0 +1,188 @@ +/*- + * Copyright (c) 2002-2003 Networks Associates Technology, Inc. + * Copyright (c) 2004-2011 Dag-Erling Smørgrav + * All rights reserved. + * + * This software was developed for the FreeBSD Project by ThinkSec AS and + * Network Associates Laboratories, the Security Research Division of + * Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 + * ("CBOSS"), as part of the DARPA CHATS research program. + * + * 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. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. + * + * $Id: openpam_dynamic.c 607 2012-04-20 11:09:37Z des $ + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <dlfcn.h> +#include <fcntl.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <security/pam_appl.h> + +#include "openpam_impl.h" + +#ifndef RTLD_NOW +#define RTLD_NOW RTLD_LAZY +#endif + +/* + * OpenPAM internal + * + * Perform sanity checks and attempt to load a module + */ + +#ifdef HAVE_FDLOPEN +static void * +try_dlopen(const char *modfn) +{ + void *dlh; + int fd; + + if ((fd = open(modfn, O_RDONLY)) < 0) + return (NULL); + if (OPENPAM_FEATURE(VERIFY_MODULE_FILE) && + openpam_check_desc_owner_perms(modfn, fd) != 0) { + close(fd); + return (NULL); + } + if ((dlh = fdlopen(fd, RTLD_NOW)) == NULL) { + openpam_log(PAM_LOG_ERROR, "%s: %s", modfn, dlerror()); + close(fd); + errno = 0; + return (NULL); + } + close(fd); + return (dlh); +} +#else +static void * +try_dlopen(const char *modfn) +{ + int check_module_file; + void *dlh; + + openpam_get_feature(OPENPAM_VERIFY_MODULE_FILE, + &check_module_file); + if (check_module_file && + openpam_check_path_owner_perms(modfn) != 0) + return (NULL); + if ((dlh = dlopen(modfn, RTLD_NOW)) == NULL) { + openpam_log(PAM_LOG_ERROR, "%s: %s", modfn, dlerror()); + errno = 0; + return (NULL); + } + return (dlh); +} +#endif + +/* + * OpenPAM internal + * + * Locate a dynamically linked module + */ + +pam_module_t * +openpam_dynamic(const char *path) +{ + const pam_module_t *dlmodule; + pam_module_t *module; + const char *prefix; + char *vpath; + void *dlh; + int i, serrno; + + dlh = NULL; + + /* Prepend the standard prefix if not an absolute pathname. */ + if (path[0] != '/') + prefix = OPENPAM_MODULES_DIR; + else + prefix = ""; + + /* try versioned module first, then unversioned module */ + if (asprintf(&vpath, "%s%s.%d", prefix, path, LIB_MAJ) < 0) + goto err; + if ((dlh = try_dlopen(vpath)) == NULL && errno == ENOENT) { + *strrchr(vpath, '.') = '\0'; + dlh = try_dlopen(vpath); + } + if (dlh == NULL) + goto err; + if ((module = calloc(1, sizeof *module)) == NULL) + goto buf_err; + if ((module->path = strdup(path)) == NULL) + goto buf_err; + module->dlh = dlh; + dlmodule = dlsym(dlh, "_pam_module"); + for (i = 0; i < PAM_NUM_PRIMITIVES; ++i) { + if (dlmodule) { + module->func[i] = dlmodule->func[i]; + } else { + module->func[i] = + (pam_func_t)dlsym(dlh, pam_sm_func_name[i]); + /* + * This openpam_log() call is a major source of + * log spam, and the cases that matter are caught + * and logged in openpam_dispatch(). This would + * be less problematic if dlerror() returned an + * error code so we could log an error only when + * dlsym() failed for a reason other than "no such + * symbol". + */ +#if 0 + if (module->func[i] == NULL) + openpam_log(PAM_LOG_DEBUG, "%s: %s(): %s", + path, pam_sm_func_name[i], dlerror()); +#endif + } + } + FREE(vpath); + return (module); +buf_err: + serrno = errno; + if (dlh != NULL) + dlclose(dlh); + FREE(module); + errno = serrno; +err: + serrno = errno; + if (errno != 0) + openpam_log(PAM_LOG_ERROR, "%s: %m", vpath); + FREE(vpath); + errno = serrno; + return (NULL); +} + +/* + * NOPARSE + */ |
