1 files changed, 215 insertions, 0 deletions
diff --git a/modules/pam_unix/pam_unix_auth.c b/modules/pam_unix/pam_unix_auth.c
new file mode 100644
index 0000000..4eccff8
--- /dev/null
+++ b/modules/pam_unix/pam_unix_auth.c
@@ -0,0 +1,215 @@
+/*
+ * pam_unix authentication management
+ *
+ * Copyright Alexander O. Yuriev, 1996.  All rights reserved.
+ * NIS+ support by Thorsten Kukuk <kukuk@weber.uni-paderborn.de>
+ * Copyright Jan Rękorajski, 1999.  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, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 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.
+ *
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ *
+ * THIS SOFTWARE IS PROVIDED ``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 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 "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <syslog.h>
+
+#include <security/_pam_macros.h>
+#include <security/pam_modules.h>
+#include <security/pam_ext.h>
+
+#include "support.h"
+
+/*
+ * PAM framework looks for these entry-points to pass control to the
+ * authentication module.
+ */
+
+/* Fun starts here :)
+
+ * pam_sm_authenticate() performs UNIX/shadow authentication
+ *
+ *      First, if shadow support is available, attempt to perform
+ *      authentication using shadow passwords. If shadow is not
+ *      available, or user does not have a shadow password, fallback
+ *      onto a normal UNIX authentication
+ */
+
+#define AUTH_RETURN						\
+do {									\
+	D(("recording return code for next time [%d]",		\
+				retval));			\
+	*ret_data = retval;					\
+	pam_set_data(pamh, "unix_setcred_return",		\
+			 (void *) ret_data, setcred_free);	\
+	D(("done. [%s]", pam_strerror(pamh, retval)));		\
+	return retval;						\
+} while (0)
+
+
+static void
+setcred_free (pam_handle_t *pamh UNUSED, void *ptr, int err UNUSED)
+{
+	if (ptr)
+		free (ptr);
+}
+
+int
+pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	unsigned long long ctrl;
+	int retval, *ret_data = NULL;
+	const char *name;
+	const char *p;
+
+	D(("called."));
+
+	ctrl = _set_ctrl(pamh, flags, NULL, NULL, NULL, argc, argv);
+
+	/* Get a few bytes so we can pass our return value to
+	   pam_sm_setcred() and pam_sm_acct_mgmt(). */
+	ret_data = malloc(sizeof(int));
+	if (!ret_data) {
+		D(("cannot malloc ret_data"));
+		pam_syslog(pamh, LOG_CRIT,
+				"pam_unix_auth: cannot allocate ret_data");
+		return PAM_BUF_ERR;
+	}
+
+	/* get the user'name' */
+
+	retval = pam_get_user(pamh, &name, NULL);
+	if (retval == PAM_SUCCESS) {
+		/*
+		 * Various libraries at various times have had bugs related to
+		 * '+' or '-' as the first character of a user name. Don't
+		 * allow this characters here.
+		 */
+		if (name[0] == '-' || name[0] == '+') {
+			pam_syslog(pamh, LOG_NOTICE, "bad username [%s]", name);
+			retval = PAM_USER_UNKNOWN;
+			AUTH_RETURN;
+		}
+		if (on(UNIX_DEBUG, ctrl))
+			pam_syslog(pamh, LOG_DEBUG, "username [%s] obtained", name);
+	} else {
+		if (retval == PAM_CONV_AGAIN) {
+			D(("pam_get_user/conv() function is not ready yet"));
+			/* it is safe to resume this function so we translate this
+			 * retval to the value that indicates we're happy to resume.
+			 */
+			retval = PAM_INCOMPLETE;
+		} else if (on(UNIX_DEBUG, ctrl)) {
+			pam_syslog(pamh, LOG_DEBUG, "could not obtain username");
+		}
+		AUTH_RETURN;
+	}
+
+	/* if this user does not have a password... */
+
+	if (_unix_blankpasswd(pamh, ctrl, name)) {
+		pam_syslog(pamh, LOG_DEBUG, "user [%s] has blank password; authenticated without it", name);
+		name = NULL;
+		retval = PAM_SUCCESS;
+		AUTH_RETURN;
+	}
+	/* get this user's authentication token */
+
+	retval = pam_get_authtok(pamh, PAM_AUTHTOK, &p , NULL);
+	if (retval != PAM_SUCCESS) {
+		if (retval != PAM_CONV_AGAIN) {
+			pam_syslog(pamh, LOG_CRIT,
+			    "auth could not identify password for [%s]", name);
+		} else {
+			D(("conversation function is not ready yet"));
+			/*
+			 * it is safe to resume this function so we translate this
+			 * retval to the value that indicates we're happy to resume.
+			 */
+			retval = PAM_INCOMPLETE;
+		}
+		name = NULL;
+		AUTH_RETURN;
+	}
+	D(("user=%s, password=[%s]", name, p));
+
+	/* verify the password of this user */
+	retval = _unix_verify_password(pamh, name, p, ctrl);
+	name = p = NULL;
+
+	AUTH_RETURN;
+}
+
+
+/*
+ * The only thing _pam_set_credentials_unix() does is initialization of
+ * UNIX group IDs.
+ *
+ * Well, everybody but me on linux-pam is convinced that it should not
+ * initialize group IDs, so I am not doing it but don't say that I haven't
+ * warned you. -- AOY
+ */
+
+int
+pam_sm_setcred (pam_handle_t *pamh, int flags,
+		int argc, const char **argv)
+{
+	int retval;
+	const void *pretval = NULL;
+	unsigned long long ctrl;
+
+	D(("called."));
+
+	ctrl = _set_ctrl(pamh, flags, NULL, NULL, NULL, argc, argv);
+
+	retval = PAM_SUCCESS;
+
+	D(("recovering return code from auth call"));
+	/* We will only find something here if UNIX_LIKE_AUTH is set --
+	   don't worry about an explicit check of argv. */
+	if (on(UNIX_LIKE_AUTH, ctrl)
+	    && pam_get_data(pamh, "unix_setcred_return", &pretval) == PAM_SUCCESS
+	    && pretval) {
+	        retval = *(const int *)pretval;
+		pam_set_data(pamh, "unix_setcred_return", NULL, NULL);
+		D(("recovered data indicates that old retval was %d", retval));
+	}
+
+	return retval;
+}