diff options
Diffstat (limited to 'contrib/openpam/lib/libpam/openpam_dynamic.c')
| -rw-r--r-- | contrib/openpam/lib/libpam/openpam_dynamic.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/contrib/openpam/lib/libpam/openpam_dynamic.c b/contrib/openpam/lib/libpam/openpam_dynamic.c new file mode 100644 index 0000000..27cd4e6 --- /dev/null +++ b/contrib/openpam/lib/libpam/openpam_dynamic.c @@ -0,0 +1,262 @@ +/*- + * 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 683 2013-04-14 14:49:59Z des $ + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <sys/param.h> + +#include <dlfcn.h> +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <security/pam_appl.h> + +#include "openpam_impl.h" +#include "openpam_asprintf.h" +#include "openpam_ctype.h" +#include "openpam_dlfunc.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; + + openpam_log(PAM_LOG_LIBDEBUG, "dlopen(%s)", modfn); + if ((fd = open(modfn, O_RDONLY)) < 0) { + if (errno != ENOENT) + openpam_log(PAM_LOG_ERROR, "%s: %m", modfn); + 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_log(PAM_LOG_LIBDEBUG, "dlopen(%s)", modfn); + 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 + +/* + * Try to load a module from the suggested location. + */ +static pam_module_t * +try_module(const char *modpath) +{ + const pam_module_t *dlmodule; + pam_module_t *module; + int i, serrno; + + if ((module = calloc(1, sizeof *module)) == NULL || + (module->path = strdup(modpath)) == NULL || + (module->dlh = try_dlopen(modpath)) == NULL) + goto err; + dlmodule = dlsym(module->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)dlfunc(module->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 + * dlfunc() failed for a reason other than "no + * such symbol". + */ +#if 0 + if (module->func[i] == NULL) + openpam_log(PAM_LOG_LIBDEBUG, "%s: %s(): %s", + modpath, pam_sm_func_name[i], dlerror()); +#endif + } + } + return (module); +err: + serrno = errno; + if (module != NULL) { + if (module->dlh != NULL) + dlclose(module->dlh); + if (module->path != NULL) + FREE(module->path); + FREE(module); + } + errno = serrno; + if (serrno != 0 && serrno != ENOENT) + openpam_log(PAM_LOG_ERROR, "%s: %m", modpath); + errno = serrno; + return (NULL); +} + +/* + * OpenPAM internal + * + * Locate a dynamically linked module + */ + +pam_module_t * +openpam_dynamic(const char *modname) +{ + pam_module_t *module; + char modpath[PATH_MAX]; + const char **path, *p; + int has_so, has_ver; + int dot, len; + + /* + * Simple case: module name contains path separator(s) + */ + if (strchr(modname, '/') != NULL) { + /* + * Absolute paths are not allowed if RESTRICT_MODULE_NAME + * is in effect (default off). Relative paths are never + * allowed. + */ + if (OPENPAM_FEATURE(RESTRICT_MODULE_NAME) || + modname[0] != '/') { + openpam_log(PAM_LOG_ERROR, + "invalid module name: %s", modname); + return (NULL); + } + return (try_module(modname)); + } + + /* + * Check for .so and version sufixes + */ + p = strchr(modname, '\0'); + has_ver = has_so = 0; + while (is_digit(*p)) + --p; + if (*p == '.' && *++p != '\0') { + /* found a numeric suffix */ + has_ver = 1; + /* assume that .so is either present or unneeded */ + has_so = 1; + } else if (*p == '\0' && p >= modname + sizeof PAM_SOEXT && + strcmp(p - sizeof PAM_SOEXT + 1, PAM_SOEXT) == 0) { + /* found .so suffix */ + has_so = 1; + } + + /* + * Complicated case: search for the module in the usual places. + */ + for (path = openpam_module_path; *path != NULL; ++path) { + /* + * Assemble the full path, including the version suffix. Take + * note of where the suffix begins so we can cut it off later. + */ + if (has_ver) + len = snprintf(modpath, sizeof modpath, "%s/%s%n", + *path, modname, &dot); + else if (has_so) + len = snprintf(modpath, sizeof modpath, "%s/%s%n.%d", + *path, modname, &dot, LIB_MAJ); + else + len = snprintf(modpath, sizeof modpath, "%s/%s%s%n.%d", + *path, modname, PAM_SOEXT, &dot, LIB_MAJ); + /* check for overflow */ + if (len < 0 || (unsigned int)len >= sizeof modpath) { + errno = ENOENT; + continue; + } + /* try the versioned path */ + if ((module = try_module(modpath)) != NULL) + return (module); + if (errno == ENOENT && modpath[dot] != '\0') { + /* no luck, try the unversioned path */ + modpath[dot] = '\0'; + if ((module = try_module(modpath)) != NULL) + return (module); + } + } + + /* :( */ + return (NULL); +} + +/* + * NOPARSE + */ |
