packetstorm sync

1 files changed, 425 insertions, 0 deletions

diff --git a/other/ssharp/auth-pam.c b/other/ssharp/auth-pam.c
new file mode 100644
index 0000000..54a2d56
--- /dev/null
+++ b/other/ssharp/auth-pam.c
@@ -0,0 +1,425 @@
+/*
+ * Copyright (c) 2000 Damien Miller.  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, 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 "includes.h"
+
+#ifdef USE_PAM
+#include "ssh.h"
+#include "xmalloc.h"
+#include "log.h"
+#include "auth-pam.h"
+#include "servconf.h"
+#include "canohost.h"
+#include "readpass.h"
+
+extern char *__progname;
+
+RCSID("$Id: auth-pam.c,v 1.1.1.1 2001/09/19 14:44:59 stealth Exp $");
+
+#define NEW_AUTHTOK_MSG \
+        "Warning: Your password has expired, please change it now"
+
+static int do_pam_conversation(int num_msg, const struct pam_message **msg,
+        struct pam_response **resp, void *appdata_ptr);
+
+/* module-local variables */
+static struct pam_conv conv = {
+        do_pam_conversation,
+        NULL
+};
+static char *__pam_msg = NULL;
+static pam_handle_t *__pamh = NULL;
+static const char *__pampasswd = NULL;
+
+/* states for do_pam_conversation() */
+enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
+/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
+static int password_change_required = 0;
+/* remember whether the last pam_authenticate() succeeded or not */
+static int was_authenticated = 0;
+
+/* Remember what has been initialised */
+static int session_opened = 0;
+static int creds_set = 0;
+
+/* accessor which allows us to switch conversation structs according to
+ * the authentication method being used */
+void do_pam_set_conv(struct pam_conv *conv)
+{
+        pam_set_item(__pamh, PAM_CONV, conv);
+}
+
+/* start an authentication run */
+int do_pam_authenticate(int flags)
+{
+        int retval = pam_authenticate(__pamh, flags);
+        was_authenticated = (retval == PAM_SUCCESS);
+        return retval;
+}
+
+/*
+ * PAM conversation function.
+ * There are two states this can run in.
+ *
+ * INITIAL_LOGIN mode simply feeds the password from the client into
+ * PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
+ * messages with into __pam_msg.  This is used during initial
+ * authentication to bypass the normal PAM password prompt.
+ *
+ * OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1)
+ * and outputs messages to stderr. This mode is used if pam_chauthtok()
+ * is called to update expired passwords.
+ */
+static int do_pam_conversation(int num_msg, const struct pam_message **msg,
+        struct pam_response **resp, void *appdata_ptr)
+{
+        struct pam_response *reply;
+        int count;
+        char buf[1024];
+
+        /* PAM will free this later */
+        reply = malloc(num_msg * sizeof(*reply));
+        if (reply == NULL)
+                return PAM_CONV_ERR;
+
+        for (count = 0; count < num_msg; count++) {
+                if (pamstate == INITIAL_LOGIN) {
+                        /*
+                         * We can't use stdio yet, queue messages for 
+                         * printing later
+                         */
+                        switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
+                        case PAM_PROMPT_ECHO_ON:
+                                free(reply);
+                                return PAM_CONV_ERR;
+                        case PAM_PROMPT_ECHO_OFF:
+                                if (__pampasswd == NULL) {
+                                        free(reply);
+                                        return PAM_CONV_ERR;
+                                }
+                                reply[count].resp = xstrdup(__pampasswd);
+                                reply[count].resp_retcode = PAM_SUCCESS;
+                                break;
+                        case PAM_ERROR_MSG:
+                        case PAM_TEXT_INFO:
+                                if ((*msg)[count].msg != NULL) {
+                                        message_cat(&__pam_msg, 
+                                            PAM_MSG_MEMBER(msg, count, msg));
+                                }
+                                reply[count].resp = xstrdup("");
+                                reply[count].resp_retcode = PAM_SUCCESS;
+                                break;
+                        default:
+                                free(reply);
+                                return PAM_CONV_ERR;
+                        }
+                } else {
+                        /*
+                         * stdio is connected, so interact directly
+                         */
+                        switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
+                        case PAM_PROMPT_ECHO_ON:
+                                fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
+                                fgets(buf, sizeof(buf), stdin);
+                                reply[count].resp = xstrdup(buf);
+                                reply[count].resp_retcode = PAM_SUCCESS;
+                                break;
+                        case PAM_PROMPT_ECHO_OFF:
+                                reply[count].resp = xstrdup(
+                                    read_passphrase(PAM_MSG_MEMBER(msg, count, 
+                                    msg), 1));
+                                reply[count].resp_retcode = PAM_SUCCESS;
+                                break;
+                        case PAM_ERROR_MSG:
+                        case PAM_TEXT_INFO:
+                                if ((*msg)[count].msg != NULL)
+                                        fprintf(stderr, "%s\n", 
+                                            PAM_MSG_MEMBER(msg, count, msg));
+                                reply[count].resp = xstrdup("");
+                                reply[count].resp_retcode = PAM_SUCCESS;
+                                break;
+                        default:
+                                free(reply);
+                                return PAM_CONV_ERR;
+                        }
+                }
+        }
+
+        *resp = reply;
+
+        return PAM_SUCCESS;
+}
+
+/* Called at exit to cleanly shutdown PAM */
+void do_pam_cleanup_proc(void *context)
+{
+        int pam_retval = PAM_SUCCESS;
+
+        if (__pamh && session_opened) {
+                pam_retval = pam_close_session(__pamh, 0);
+                if (pam_retval != PAM_SUCCESS)
+                        log("Cannot close PAM session[%d]: %.200s",
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+        }
+
+        if (__pamh && creds_set) {
+                pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
+                if (pam_retval != PAM_SUCCESS)
+                        debug("Cannot delete credentials[%d]: %.200s", 
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+        }
+
+        if (__pamh) {
+                pam_retval = pam_end(__pamh, pam_retval);
+                if (pam_retval != PAM_SUCCESS)
+                        log("Cannot release PAM authentication[%d]: %.200s",
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+        }
+}
+
+/* Attempt password authentation using PAM */
+int auth_pam_password(struct passwd *pw, const char *password)
+{
+        extern ServerOptions options;
+        int pam_retval;
+
+        do_pam_set_conv(&conv);
+
+        /* deny if no user. */
+        if (pw == NULL)
+                return 0;
+        if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
+                return 0;
+        if (*password == '\0' && options.permit_empty_passwd == 0)
+                return 0;
+
+        __pampasswd = password;
+
+        pamstate = INITIAL_LOGIN;
+        pam_retval = do_pam_authenticate(0);
+        if (pam_retval == PAM_SUCCESS) {
+                debug("PAM Password authentication accepted for "
+                    "user \"%.100s\"", pw->pw_name);
+                return 1;
+        } else {
+                debug("PAM Password authentication for \"%.100s\" "
+                    "failed[%d]: %s", pw->pw_name, pam_retval, 
+                    PAM_STRERROR(__pamh, pam_retval));
+                return 0;
+        }
+}
+
+/* Do account management using PAM */
+int do_pam_account(char *username, char *remote_user)
+{
+        int pam_retval;
+
+        do_pam_set_conv(&conv);
+
+        if (remote_user) {
+                debug("PAM setting ruser to \"%.200s\"", remote_user);
+                pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
+                if (pam_retval != PAM_SUCCESS)
+                        fatal("PAM set ruser failed[%d]: %.200s", pam_retval, 
+                            PAM_STRERROR(__pamh, pam_retval));
+        }
+
+        pam_retval = pam_acct_mgmt(__pamh, 0);
+        switch (pam_retval) {
+                case PAM_SUCCESS:
+                        /* This is what we want */
+                        break;
+                case PAM_NEW_AUTHTOK_REQD:
+                        message_cat(&__pam_msg, NEW_AUTHTOK_MSG);
+                        /* flag that password change is necessary */
+                        password_change_required = 1;
+                        break;
+                default:
+                        log("PAM rejected by account configuration[%d]: "
+                            "%.200s", pam_retval, PAM_STRERROR(__pamh, 
+                            pam_retval));
+                        return(0);
+        }
+
+        return(1);
+}
+
+/* Do PAM-specific session initialisation */
+void do_pam_session(char *username, const char *ttyname)
+{
+        int pam_retval;
+
+        do_pam_set_conv(&conv);
+
+        if (ttyname != NULL) {
+                debug("PAM setting tty to \"%.200s\"", ttyname);
+                pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
+                if (pam_retval != PAM_SUCCESS)
+                        fatal("PAM set tty failed[%d]: %.200s",
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+        }
+
+        pam_retval = pam_open_session(__pamh, 0);
+        if (pam_retval != PAM_SUCCESS)
+                fatal("PAM session setup failed[%d]: %.200s",
+                    pam_retval, PAM_STRERROR(__pamh, pam_retval));
+
+        session_opened = 1;
+}
+
+/* Set PAM credentials */
+void do_pam_setcred(int init)
+{
+        int pam_retval;
+
+        do_pam_set_conv(&conv);
+
+        debug("PAM establishing creds");
+        pam_retval = pam_setcred(__pamh, 
+            init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_CRED);
+        if (pam_retval != PAM_SUCCESS) {
+                if (was_authenticated)
+                        fatal("PAM setcred failed[%d]: %.200s",
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+                else
+                        debug("PAM setcred failed[%d]: %.200s",
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+        } else
+                creds_set = 1;
+}
+
+/* accessor function for file scope static variable */
+int is_pam_password_change_required(void)
+{
+        return password_change_required;
+}
+
+/*
+ * Have user change authentication token if pam_acct_mgmt() indicated
+ * it was expired.  This needs to be called after an interactive
+ * session is established and the user's pty is connected to
+ * stdin/stout/stderr.
+ */
+void do_pam_chauthtok(void)
+{
+        int pam_retval;
+
+        do_pam_set_conv(&conv);
+
+        if (password_change_required) {
+                pamstate = OTHER;
+                pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
+                if (pam_retval != PAM_SUCCESS)
+                        fatal("PAM pam_chauthtok failed[%d]: %.200s",
+                            pam_retval, PAM_STRERROR(__pamh, pam_retval));
+        }
+}
+
+/* Cleanly shutdown PAM */
+void finish_pam(void)
+{
+        do_pam_cleanup_proc(NULL);
+        fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
+}
+
+/* Start PAM authentication for specified account */
+void start_pam(const char *user)
+{
+        int pam_retval;
+        extern ServerOptions options;
+        extern u_int utmp_len;
+        const char *rhost;
+
+        debug("Starting up PAM with username \"%.200s\"", user);
+
+        pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
+
+        if (pam_retval != PAM_SUCCESS)
+                fatal("PAM initialisation failed[%d]: %.200s",
+                    pam_retval, PAM_STRERROR(__pamh, pam_retval));
+
+        rhost = get_remote_name_or_ip(utmp_len, options.reverse_mapping_check);
+        debug("PAM setting rhost to \"%.200s\"", rhost);
+
+        pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
+        if (pam_retval != PAM_SUCCESS)
+                fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
+                    PAM_STRERROR(__pamh, pam_retval));
+#ifdef PAM_TTY_KLUDGE
+        /*
+         * Some PAM modules (e.g. pam_time) require a TTY to operate,
+         * and will fail in various stupid ways if they don't get one.
+         * sshd doesn't set the tty until too late in the auth process and may
+         * not even need one (for tty-less connections)
+         * Kludge: Set a fake PAM_TTY
+         */
+        pam_retval = pam_set_item(__pamh, PAM_TTY, "ssh");
+        if (pam_retval != PAM_SUCCESS)
+                fatal("PAM set tty failed[%d]: %.200s",
+                    pam_retval, PAM_STRERROR(__pamh, pam_retval));
+#endif /* PAM_TTY_KLUDGE */
+
+        fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
+}
+
+/* Return list of PAM enviornment strings */
+char **fetch_pam_environment(void)
+{
+#ifdef HAVE_PAM_GETENVLIST
+        return(pam_getenvlist(__pamh));
+#else /* HAVE_PAM_GETENVLIST */
+        return(NULL);
+#endif /* HAVE_PAM_GETENVLIST */
+}
+
+/* Print any messages that have been generated during authentication */
+/* or account checking to stderr */
+void print_pam_messages(void)
+{
+        if (__pam_msg != NULL)
+                fputs(__pam_msg, stderr);
+}
+
+/* Append a message to buffer */
+void message_cat(char **p, const char *a)
+{
+        char *cp;
+        size_t new_len;
+
+        new_len = strlen(a);
+
+        if (*p) {
+                size_t len = strlen(*p);
+
+                *p = xrealloc(*p, new_len + len + 2);
+                cp = *p + len;
+        } else
+                *p = cp = xmalloc(new_len + 2);
+
+        memcpy(cp, a, new_len);
+        cp[new_len] = '\n';
+        cp[new_len + 1] = '\0';
+}
+
+#endif /* USE_PAM */