Upgrade to the pam_ssh module, version 1.1..
(From the author:) Primarily, I have added built-in functions for manipulating the environment, so putenv() is no longer used. XDM and its variants should now work without modification. Note that the new code uses the macros in <sys/queue.h>. Submitted by: Andrew J. Korty <ajk@iu.edu>
This commit is contained in:
Brian Feldman
parent
3600eb76c6
commit
0e17bca17c
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=55166
@ -29,6 +29,7 @@
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#include <sys/param.h>
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#include <sys/queue.h>
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#include <fcntl.h>
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#include <paths.h>
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@ -69,6 +70,127 @@ ssh_cleanup(pam_handle_t *pamh, void *data, int error_status)
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}
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/*
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* The following set of functions allow the module to manipulate the
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* environment without calling the putenv() or setenv() stdlib functions.
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* At least one version of these functions, on the first call, copies
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* the environment into dynamically-allocated memory and then augments
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* it. On subsequent calls, the realloc() call is used to grow the
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* previously allocated buffer. Problems arise when the "environ"
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* variable is changed to point to static memory after putenv()/setenv()
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* have been called.
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*
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* We don't use putenv() or setenv() in case the application subsequently
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* manipulates environ, (e.g., to clear the environment by pointing
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* environ at an array of one element equal to NULL).
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*/
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SLIST_HEAD(env_head, env_entry);
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struct env_entry {
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char *ee_env;
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SLIST_ENTRY(env_entry) ee_entries;
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};
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typedef struct env {
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char **e_environ_orig;
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char **e_environ_new;
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int e_count;
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struct env_head e_head;
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int e_committed;
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} ENV;
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extern char **environ;
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static ENV *
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env_new(void)
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{
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ENV *self;
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if (!(self = malloc(sizeof (ENV)))) {
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syslog(LOG_CRIT, "%m");
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return NULL;
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}
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SLIST_INIT(&self->e_head);
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self->e_count = 0;
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self->e_committed = 0;
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return self;
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}
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static int
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env_put(ENV *self, char *s)
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{
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struct env_entry *env;
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if (!(env = malloc(sizeof (struct env_entry))) ||
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!(env->ee_env = strdup(s))) {
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syslog(LOG_CRIT, "%m");
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return PAM_SERVICE_ERR;
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}
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SLIST_INSERT_HEAD(&self->e_head, env, ee_entries);
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++self->e_count;
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return PAM_SUCCESS;
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}
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static void
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env_swap(ENV *self, int which)
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{
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environ = which ? self->e_environ_new : self->e_environ_orig;
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}
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static int
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env_commit(ENV *self)
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{
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int n;
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struct env_entry *p;
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char **v;
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for (v = environ, n = 0; v && *v; v++, n++)
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;
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if (!(v = malloc((n + self->e_count + 1) * sizeof (char *)))) {
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syslog(LOG_CRIT, "%m");
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return PAM_SERVICE_ERR;
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}
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self->e_committed = 1;
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(void)memcpy(v, environ, n * sizeof (char *));
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SLIST_FOREACH(p, &self->e_head, ee_entries)
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v[n++] = p->ee_env;
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v[n] = NULL;
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self->e_environ_orig = environ;
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self->e_environ_new = v;
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env_swap(self, 1);
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return PAM_SUCCESS;
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}
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static void
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env_destroy(ENV *self)
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{
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struct env_entry *p;
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env_swap(self, 0);
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SLIST_FOREACH(p, &self->e_head, ee_entries) {
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free(p->ee_env);
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free(p);
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}
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if (self->e_committed)
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free(self->e_environ_new);
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free(self);
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}
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void
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env_cleanup(pam_handle_t *pamh, void *data, int error_status)
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{
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if (data)
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env_destroy(data);
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}
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typedef struct passwd PASSWD;
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PAM_EXTERN int
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@ -210,6 +332,7 @@ pam_sm_open_session(
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const PASSWD *pwent; /* user's passwd entry */
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int retval; /* from calls */
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uid_t saved_uid; /* caller's uid */
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ENV *ssh_env; /* env handle */
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const char *tty; /* tty or display name */
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char hname[MAXHOSTNAMELEN]; /* local hostname */
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char parse[BUFSIZ]; /* commands output */
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@ -251,51 +374,71 @@ pam_sm_open_session(
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(void)fclose(env_fp);
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return PAM_SESSION_ERR;
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}
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if (!(ssh_env = env_new()))
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return PAM_SESSION_ERR;
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if ((retval = pam_set_data(pamh, "ssh_env_handle", ssh_env,
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env_cleanup)) != PAM_SUCCESS)
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return retval;
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while (fgets(parse, sizeof parse, pipe)) {
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if (env_fp)
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(void)fputs(parse, env_fp);
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/*
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* Save environment for application with pam_putenv()
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* but also with putenv() for our own call to
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* but also with env_* functions for our own call to
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* ssh_get_authentication_connection().
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*/
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if (strchr(parse, '=') && (env_end = strchr(parse, ';'))) {
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*env_end = '\0';
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/* pass to the application ... */
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if (!((retval = pam_putenv(pamh, parse)) ==
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PAM_SUCCESS && putenv(parse) == 0)) {
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PAM_SUCCESS)) {
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(void)pclose(pipe);
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if (env_fp)
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(void)fclose(env_fp);
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env_destroy(ssh_env);
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return PAM_SERVICE_ERR;
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}
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env_put(ssh_env, parse);
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}
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}
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if (env_fp)
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(void)fclose(env_fp);
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retval = pclose(pipe);
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if (retval > 0) {
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switch (retval = pclose(pipe)) {
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case -1:
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syslog(LOG_ERR, "%s: %s: %m", MODULE_NAME, PATH_SSH_AGENT);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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case 0:
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break;
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case 127:
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syslog(LOG_ERR, "%s: cannot execute %s", MODULE_NAME,
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PATH_SSH_AGENT);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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default:
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syslog(LOG_ERR, "%s: %s exited with status %d",
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MODULE_NAME, PATH_SSH_AGENT, WEXITSTATUS(retval));
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return PAM_SESSION_ERR;
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} else if (retval < 0) {
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syslog(LOG_ERR, "%s: %s: %m", MODULE_NAME, PATH_SSH_AGENT);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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}
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/* connect to the agent and hand off the private key */
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if ((retval = pam_get_data(pamh, "ssh_private_key",
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(const void **)&key)) != PAM_SUCCESS)
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return retval;
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if ((retval = pam_get_data(pamh, "ssh_key_comment",
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(const void **)&comment)) != PAM_SUCCESS)
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(const void **)&key)) != PAM_SUCCESS ||
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(retval = pam_get_data(pamh, "ssh_key_comment",
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(const void **)&comment)) != PAM_SUCCESS ||
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(retval = env_commit(ssh_env)) != PAM_SUCCESS) {
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env_destroy(ssh_env);
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return retval;
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}
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if (!(ac = ssh_get_authentication_connection())) {
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syslog(LOG_ERR, "%s: could not connect to agent",
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MODULE_NAME);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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}
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retval = ssh_add_identity(ac, key, comment);
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ssh_close_authentication_connection(ac);
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env_swap(ssh_env, 0);
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return retval ? PAM_SUCCESS : PAM_SESSION_ERR;
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}
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@ -309,9 +452,27 @@ pam_sm_close_session(
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{
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const char *env_file; /* ssh-agent environment */
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int retval; /* from calls */
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ENV *ssh_env; /* env handle */
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if ((retval = pam_get_data(pamh, "ssh_env_handle",
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(const void **)&ssh_env)) != PAM_SUCCESS)
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return retval;
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env_swap(ssh_env, 1);
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/* kill the agent */
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if ((retval = system(PATH_SSH_AGENT " -k")) != 0) {
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retval = system(PATH_SSH_AGENT " -k");
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env_destroy(ssh_env);
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switch (retval) {
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case -1:
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syslog(LOG_ERR, "%s: %s -k: %m", MODULE_NAME,
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PATH_SSH_AGENT);
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return PAM_SESSION_ERR;
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case 0:
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break;
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case 127:
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syslog(LOG_ERR, "%s: cannot execute %s -k", MODULE_NAME,
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PATH_SSH_AGENT);
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return PAM_SESSION_ERR;
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default:
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syslog(LOG_ERR, "%s: %s -k exited with status %d",
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MODULE_NAME, PATH_SSH_AGENT, WEXITSTATUS(retval));
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return PAM_SESSION_ERR;
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@ -29,6 +29,7 @@
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#include <sys/param.h>
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#include <sys/queue.h>
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#include <fcntl.h>
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#include <paths.h>
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@ -69,6 +70,127 @@ ssh_cleanup(pam_handle_t *pamh, void *data, int error_status)
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}
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/*
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* The following set of functions allow the module to manipulate the
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* environment without calling the putenv() or setenv() stdlib functions.
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* At least one version of these functions, on the first call, copies
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* the environment into dynamically-allocated memory and then augments
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* it. On subsequent calls, the realloc() call is used to grow the
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* previously allocated buffer. Problems arise when the "environ"
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* variable is changed to point to static memory after putenv()/setenv()
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* have been called.
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*
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* We don't use putenv() or setenv() in case the application subsequently
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* manipulates environ, (e.g., to clear the environment by pointing
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* environ at an array of one element equal to NULL).
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*/
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SLIST_HEAD(env_head, env_entry);
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struct env_entry {
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char *ee_env;
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SLIST_ENTRY(env_entry) ee_entries;
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};
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typedef struct env {
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char **e_environ_orig;
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char **e_environ_new;
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int e_count;
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struct env_head e_head;
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int e_committed;
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} ENV;
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extern char **environ;
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static ENV *
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env_new(void)
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{
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ENV *self;
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if (!(self = malloc(sizeof (ENV)))) {
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syslog(LOG_CRIT, "%m");
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return NULL;
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}
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SLIST_INIT(&self->e_head);
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self->e_count = 0;
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self->e_committed = 0;
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return self;
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}
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static int
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env_put(ENV *self, char *s)
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{
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struct env_entry *env;
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if (!(env = malloc(sizeof (struct env_entry))) ||
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!(env->ee_env = strdup(s))) {
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syslog(LOG_CRIT, "%m");
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return PAM_SERVICE_ERR;
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}
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SLIST_INSERT_HEAD(&self->e_head, env, ee_entries);
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++self->e_count;
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return PAM_SUCCESS;
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}
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static void
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env_swap(ENV *self, int which)
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{
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environ = which ? self->e_environ_new : self->e_environ_orig;
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}
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static int
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env_commit(ENV *self)
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{
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int n;
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struct env_entry *p;
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char **v;
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for (v = environ, n = 0; v && *v; v++, n++)
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;
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if (!(v = malloc((n + self->e_count + 1) * sizeof (char *)))) {
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syslog(LOG_CRIT, "%m");
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return PAM_SERVICE_ERR;
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}
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self->e_committed = 1;
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(void)memcpy(v, environ, n * sizeof (char *));
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SLIST_FOREACH(p, &self->e_head, ee_entries)
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v[n++] = p->ee_env;
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v[n] = NULL;
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self->e_environ_orig = environ;
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self->e_environ_new = v;
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env_swap(self, 1);
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return PAM_SUCCESS;
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}
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static void
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env_destroy(ENV *self)
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{
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struct env_entry *p;
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env_swap(self, 0);
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SLIST_FOREACH(p, &self->e_head, ee_entries) {
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free(p->ee_env);
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free(p);
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}
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if (self->e_committed)
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free(self->e_environ_new);
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free(self);
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}
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void
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env_cleanup(pam_handle_t *pamh, void *data, int error_status)
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{
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if (data)
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env_destroy(data);
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}
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typedef struct passwd PASSWD;
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PAM_EXTERN int
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@ -210,6 +332,7 @@ pam_sm_open_session(
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const PASSWD *pwent; /* user's passwd entry */
|
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int retval; /* from calls */
|
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uid_t saved_uid; /* caller's uid */
|
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ENV *ssh_env; /* env handle */
|
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const char *tty; /* tty or display name */
|
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char hname[MAXHOSTNAMELEN]; /* local hostname */
|
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char parse[BUFSIZ]; /* commands output */
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@ -251,51 +374,71 @@ pam_sm_open_session(
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(void)fclose(env_fp);
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return PAM_SESSION_ERR;
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}
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if (!(ssh_env = env_new()))
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return PAM_SESSION_ERR;
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if ((retval = pam_set_data(pamh, "ssh_env_handle", ssh_env,
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env_cleanup)) != PAM_SUCCESS)
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return retval;
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while (fgets(parse, sizeof parse, pipe)) {
|
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if (env_fp)
|
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(void)fputs(parse, env_fp);
|
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/*
|
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* Save environment for application with pam_putenv()
|
||||
* but also with putenv() for our own call to
|
||||
* but also with env_* functions for our own call to
|
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* ssh_get_authentication_connection().
|
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*/
|
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if (strchr(parse, '=') && (env_end = strchr(parse, ';'))) {
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*env_end = '\0';
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/* pass to the application ... */
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if (!((retval = pam_putenv(pamh, parse)) ==
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PAM_SUCCESS && putenv(parse) == 0)) {
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PAM_SUCCESS)) {
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(void)pclose(pipe);
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if (env_fp)
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(void)fclose(env_fp);
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env_destroy(ssh_env);
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return PAM_SERVICE_ERR;
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}
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env_put(ssh_env, parse);
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}
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}
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if (env_fp)
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(void)fclose(env_fp);
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retval = pclose(pipe);
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if (retval > 0) {
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switch (retval = pclose(pipe)) {
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case -1:
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syslog(LOG_ERR, "%s: %s: %m", MODULE_NAME, PATH_SSH_AGENT);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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case 0:
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break;
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case 127:
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syslog(LOG_ERR, "%s: cannot execute %s", MODULE_NAME,
|
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PATH_SSH_AGENT);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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default:
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syslog(LOG_ERR, "%s: %s exited with status %d",
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MODULE_NAME, PATH_SSH_AGENT, WEXITSTATUS(retval));
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return PAM_SESSION_ERR;
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} else if (retval < 0) {
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syslog(LOG_ERR, "%s: %s: %m", MODULE_NAME, PATH_SSH_AGENT);
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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}
|
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/* connect to the agent and hand off the private key */
|
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if ((retval = pam_get_data(pamh, "ssh_private_key",
|
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(const void **)&key)) != PAM_SUCCESS)
|
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return retval;
|
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if ((retval = pam_get_data(pamh, "ssh_key_comment",
|
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(const void **)&comment)) != PAM_SUCCESS)
|
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(const void **)&key)) != PAM_SUCCESS ||
|
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(retval = pam_get_data(pamh, "ssh_key_comment",
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(const void **)&comment)) != PAM_SUCCESS ||
|
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(retval = env_commit(ssh_env)) != PAM_SUCCESS) {
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env_destroy(ssh_env);
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return retval;
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}
|
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if (!(ac = ssh_get_authentication_connection())) {
|
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syslog(LOG_ERR, "%s: could not connect to agent",
|
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MODULE_NAME);
|
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env_destroy(ssh_env);
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return PAM_SESSION_ERR;
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}
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retval = ssh_add_identity(ac, key, comment);
|
||||
ssh_close_authentication_connection(ac);
|
||||
env_swap(ssh_env, 0);
|
||||
return retval ? PAM_SUCCESS : PAM_SESSION_ERR;
|
||||
}
|
||||
|
||||
@ -309,9 +452,27 @@ pam_sm_close_session(
|
||||
{
|
||||
const char *env_file; /* ssh-agent environment */
|
||||
int retval; /* from calls */
|
||||
ENV *ssh_env; /* env handle */
|
||||
|
||||
if ((retval = pam_get_data(pamh, "ssh_env_handle",
|
||||
(const void **)&ssh_env)) != PAM_SUCCESS)
|
||||
return retval;
|
||||
env_swap(ssh_env, 1);
|
||||
/* kill the agent */
|
||||
if ((retval = system(PATH_SSH_AGENT " -k")) != 0) {
|
||||
retval = system(PATH_SSH_AGENT " -k");
|
||||
env_destroy(ssh_env);
|
||||
switch (retval) {
|
||||
case -1:
|
||||
syslog(LOG_ERR, "%s: %s -k: %m", MODULE_NAME,
|
||||
PATH_SSH_AGENT);
|
||||
return PAM_SESSION_ERR;
|
||||
case 0:
|
||||
break;
|
||||
case 127:
|
||||
syslog(LOG_ERR, "%s: cannot execute %s -k", MODULE_NAME,
|
||||
PATH_SSH_AGENT);
|
||||
return PAM_SESSION_ERR;
|
||||
default:
|
||||
syslog(LOG_ERR, "%s: %s -k exited with status %d",
|
||||
MODULE_NAME, PATH_SSH_AGENT, WEXITSTATUS(retval));
|
||||
return PAM_SESSION_ERR;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user