+/*
+Copyright (c) 2013 Eugene Crosser
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must
+ not claim that you wrote the original software. If you use this
+ software in a product, an acknowledgment in the product documentation
+ would be appreciated but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must
+ not be misrepresented as being the original software.
+
+ 3. This notice may not be removed or altered from any source
+ distribution.
+*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <syslog.h>
+#include "authobj.h"
+#include "authfile.h"
+#include "pcsc_cr.h"
+
+#ifndef PIC
+# define PAM_STATIC
+#endif
+
+#define PAM_SM_AUTH
+
+#ifdef HAVE_SECURITY_PAM_APPL_H
+# include <security/pam_appl.h>
+#endif
+#ifdef HAVE_SECURITY_PAM_MODULES_H
+# include <security/pam_modules.h>
+#endif
+#ifdef HAVE_SECURITY_PAM_EXT_H
+# include <security/pam_ext.h>
+#endif
+
+#ifndef PAM_EXTERN
+# ifdef PAM_STATIC
+# define PAM_EXTERN static
+# else
+# define PAM_EXTERN extern
+# endif
+#endif
+
+struct _cfg {
+ int noaskpass;
+ int verbose;
+ int injectauth;
+};
+
+#ifndef HAVE_PAM_GET_AUTHTOK
+static int pam_get_authtok(pam_handle_t *pamh, int item, const char **authtok,
+ const char *prompt)
+{
+ struct _cfg dfl_cfg = {0};
+ struct _cfg *cfg = &dfl_cfg;
+ struct pam_conv *conv;
+ struct pam_message msg;
+ const struct pam_message *msgp;
+ struct pam_response *resp;
+ int pam_err;
+
+ (void)pam_get_data(pamh, "pcsc_cr_cfg_struct", (const void **)&cfg);
+
+ if ((pam_err = pam_get_item(pamh, PAM_AUTHTOK,
+ (const void **)authtok))) {
+ if (cfg->verbose) syslog(LOG_ERR,
+ "get_item(PAM_AUTHTOK) failed: %s",
+ pam_strerror(pamh, pam_err));
+ } else {
+ if (*authtok) return PAM_SUCCESS;
+ }
+
+ if ((pam_err = pam_get_item(pamh, PAM_CONV,
+ (const void **)&conv))) {
+ if (cfg->verbose) syslog(LOG_ERR,
+ "get_item(PAM_CONV) failed: %s",
+ pam_strerror(pamh, pam_err));
+ return pam_err;
+ }
+ msg.msg_style = PAM_PROMPT_ECHO_OFF;
+ msg.msg = prompt;
+ msgp = &msg;
+ resp = NULL;
+ pam_err = (*conv->conv)(1, &msgp, &resp, conv->appdata_ptr);
+ if (resp != NULL) {
+ if (pam_err == PAM_SUCCESS) *authtok = resp->resp;
+ else free(resp->resp);
+ free(resp);
+ }
+ return pam_err;
+}
+#endif
+
+static struct _auth_chunk
+token_key(const unsigned char *challenge, const int challengesize)
+{
+ struct _auth_chunk ho = {0};
+ long rc;
+ int keysize = sizeof(ho.data);
+
+ if ((rc = pcsc_cr(challenge, challengesize, ho.data, &keysize))) {
+ ho.err = pcsc_errstr(rc);
+ }
+ return ho;
+}
+
+static void update_nonce(char *nonce, const int nonsize)
+{
+ int n = 0;
+
+ sscanf(nonce, "%d", &n);
+ snprintf(nonce, nonsize, "%d", n+1);
+}
+
+void parse_cfg(struct _cfg * const cfg, int argc, const char *argv[])
+{
+ int i;
+
+ for (i = 0; i < argc; i++) {
+ if (strchr(argv[i],':') && strchr(argv[i],'=')) {
+ if (pcsc_option(argv[i]))
+ syslog(LOG_ERR,
+ "unrecognized pcsc backedn option \"%s\"",
+ argv[i]);
+ } else if (!strcmp(argv[i], "verbose")) cfg->verbose = 1;
+ else if (!strcmp(argv[i], "noaskpass")) cfg->noaskpass = 1;
+ else if (!strcmp(argv[i], "injectauth")) cfg->injectauth = 1;
+ else if (!strncmp(argv[i], "path=", 5))
+ authfile_template(argv[i]+5);
+ else syslog(LOG_ERR, "unrecognized arg: \"%s\"", argv[i]);
+
+ if (cfg->verbose) syslog(LOG_DEBUG, "arg: \"%s\"", argv[i]);
+ }
+}
+
+PAM_EXTERN int
+pam_sm_authenticate(pam_handle_t *pamh, int flags,
+ int argc, const char *argv[])
+{
+ struct _cfg cfg = {0};
+ const char *user;
+ const char *password;
+ struct _auth_obj ao;
+ int pam_err;
+
+ parse_cfg(&cfg, argc, argv);
+ (void)pam_set_data(pamh, "pcsc_cr_cfg_struct", &cfg, NULL);
+ if (cfg.verbose) syslog(LOG_INFO, "auth with %s", PACKAGE_STRING);
+
+ if ((pam_err = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS) {
+ if (cfg.verbose) syslog(LOG_ERR, "get_user failed: %s",
+ pam_strerror(pamh, pam_err));
+ return pam_err;
+ }
+ if (cfg.verbose) syslog(LOG_DEBUG, "user=\"%s\"", user?user:"<none>");
+
+ if (!cfg.noaskpass) {
+ if ((pam_err = pam_get_authtok(pamh, PAM_AUTHTOK,
+ (const char **)&password,
+ "Token password:"))) {
+ if (cfg.verbose) syslog(LOG_ERR,
+ "get_authtok failed: %s",
+ pam_strerror(pamh, pam_err));
+ return pam_err;
+ }
+ } else {
+ password = "";
+ }
+
+ ao = authfile(user, password, update_nonce,
+ NULL, 0, NULL, 0, token_key);
+ if (ao.err) {
+ if (cfg.verbose) syslog(LOG_INFO, "authfile: %s", ao.err);
+ return PAM_AUTH_ERR;
+ } else {
+ /* Just because we can. Probably not much use for that. */
+ /* Userid written in authfile may differ from the login one. */
+ pam_set_item(pamh, PAM_USER, ao.data);
+ if (cfg.injectauth && ao.payload && ao.payload[0])
+ pam_set_item(pamh, PAM_AUTHTOK, ao.payload);
+ if (cfg.verbose) syslog(LOG_DEBUG, "authenticated");
+ return PAM_SUCCESS;
+ }
+}
+
+PAM_EXTERN int
+pam_sm_setcred(pam_handle_t *pamh, int flags,
+ int argc, const char *argv[])
+{
+ return PAM_SUCCESS;
+}
+
+PAM_EXTERN int
+pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
+ int argc, const char *argv[])
+{
+ return PAM_SUCCESS;
+}
+
+PAM_EXTERN int
+pam_sm_open_session(pam_handle_t *pamh, int flags,
+ int argc, const char *argv[])
+{
+ return PAM_SUCCESS;
+}
+
+PAM_EXTERN int
+pam_sm_close_session(pam_handle_t *pamh, int flags,
+ int argc, const char *argv[])
+{
+ return PAM_SUCCESS;
+}
+
+PAM_EXTERN int
+pam_sm_chauthtok(pam_handle_t *pamh, int flags,
+ int argc, const char *argv[])
+{
+ return PAM_SERVICE_ERR;
+}
+
+#ifdef PAM_MODULE_ENTRY
+PAM_MODULE_ENTRY("pam_pcsc_cr");
+#endif
+
+#ifdef PAM_STATIC
+struct pam_module _pam_pcsc_cr_modstruct = {
+ "pam_pcsc_cr",
+ pam_sm_authenticate,
+ pam_sm_setcred,
+ pam_sm_acct_mgmt,
+ pam_sm_open_session,
+ pam_sm_close_session,
+ pam_sm_chauthtok
+};
+#endif
projects / pam_pcsc_cr.git / blobdiff