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authorgreen <green@FreeBSD.org>1999-12-28 05:32:54 +0000
committergreen <green@FreeBSD.org>1999-12-28 05:32:54 +0000
commit8b8214b6d3bce6e64a982ab67d5d17dfa3f85b0b (patch)
tree9f93ce573679058dea9e28ab39be13eb5f574011 /crypto/openssh/pam_ssh
parent363b7bd53715dfc3c4b8bc6809fed0a241c34a9a (diff)
downloadFreeBSD-src-8b8214b6d3bce6e64a982ab67d5d17dfa3f85b0b.zip
FreeBSD-src-8b8214b6d3bce6e64a982ab67d5d17dfa3f85b0b.tar.gz
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>
Diffstat (limited to 'crypto/openssh/pam_ssh')
-rw-r--r--crypto/openssh/pam_ssh/pam_ssh.c185
1 files changed, 173 insertions, 12 deletions
diff --git a/crypto/openssh/pam_ssh/pam_ssh.c b/crypto/openssh/pam_ssh/pam_ssh.c
index 8e22d3f..9392b9e 100644
--- a/crypto/openssh/pam_ssh/pam_ssh.c
+++ b/crypto/openssh/pam_ssh/pam_ssh.c
@@ -29,6 +29,7 @@
#include <sys/param.h>
+#include <sys/queue.h>
#include <fcntl.h>
#include <paths.h>
@@ -69,6 +70,127 @@ ssh_cleanup(pam_handle_t *pamh, void *data, int error_status)
}
+/*
+ * The following set of functions allow the module to manipulate the
+ * environment without calling the putenv() or setenv() stdlib functions.
+ * At least one version of these functions, on the first call, copies
+ * the environment into dynamically-allocated memory and then augments
+ * it. On subsequent calls, the realloc() call is used to grow the
+ * previously allocated buffer. Problems arise when the "environ"
+ * variable is changed to point to static memory after putenv()/setenv()
+ * have been called.
+ *
+ * We don't use putenv() or setenv() in case the application subsequently
+ * manipulates environ, (e.g., to clear the environment by pointing
+ * environ at an array of one element equal to NULL).
+ */
+
+SLIST_HEAD(env_head, env_entry);
+
+struct env_entry {
+ char *ee_env;
+ SLIST_ENTRY(env_entry) ee_entries;
+};
+
+typedef struct env {
+ char **e_environ_orig;
+ char **e_environ_new;
+ int e_count;
+ struct env_head e_head;
+ int e_committed;
+} ENV;
+
+extern char **environ;
+
+
+static ENV *
+env_new(void)
+{
+ ENV *self;
+
+ if (!(self = malloc(sizeof (ENV)))) {
+ syslog(LOG_CRIT, "%m");
+ return NULL;
+ }
+ SLIST_INIT(&self->e_head);
+ self->e_count = 0;
+ self->e_committed = 0;
+ return self;
+}
+
+
+static int
+env_put(ENV *self, char *s)
+{
+ struct env_entry *env;
+
+ if (!(env = malloc(sizeof (struct env_entry))) ||
+ !(env->ee_env = strdup(s))) {
+ syslog(LOG_CRIT, "%m");
+ return PAM_SERVICE_ERR;
+ }
+ SLIST_INSERT_HEAD(&self->e_head, env, ee_entries);
+ ++self->e_count;
+ return PAM_SUCCESS;
+}
+
+
+static void
+env_swap(ENV *self, int which)
+{
+ environ = which ? self->e_environ_new : self->e_environ_orig;
+}
+
+
+static int
+env_commit(ENV *self)
+{
+ int n;
+ struct env_entry *p;
+ char **v;
+
+ for (v = environ, n = 0; v && *v; v++, n++)
+ ;
+ if (!(v = malloc((n + self->e_count + 1) * sizeof (char *)))) {
+ syslog(LOG_CRIT, "%m");
+ return PAM_SERVICE_ERR;
+ }
+ self->e_committed = 1;
+ (void)memcpy(v, environ, n * sizeof (char *));
+ SLIST_FOREACH(p, &self->e_head, ee_entries)
+ v[n++] = p->ee_env;
+ v[n] = NULL;
+ self->e_environ_orig = environ;
+ self->e_environ_new = v;
+ env_swap(self, 1);
+ return PAM_SUCCESS;
+}
+
+
+static void
+env_destroy(ENV *self)
+{
+ struct env_entry *p;
+
+ env_swap(self, 0);
+ SLIST_FOREACH(p, &self->e_head, ee_entries) {
+ free(p->ee_env);
+ free(p);
+ }
+ if (self->e_committed)
+ free(self->e_environ_new);
+ free(self);
+}
+
+
+void
+env_cleanup(pam_handle_t *pamh, void *data, int error_status)
+{
+ if (data)
+ env_destroy(data);
+}
+
+
typedef struct passwd PASSWD;
PAM_EXTERN int
@@ -210,6 +332,7 @@ pam_sm_open_session(
const PASSWD *pwent; /* user's passwd entry */
int retval; /* from calls */
uid_t saved_uid; /* caller's uid */
+ ENV *ssh_env; /* env handle */
const char *tty; /* tty or display name */
char hname[MAXHOSTNAMELEN]; /* local hostname */
char parse[BUFSIZ]; /* commands output */
@@ -251,51 +374,71 @@ pam_sm_open_session(
(void)fclose(env_fp);
return PAM_SESSION_ERR;
}
+ if (!(ssh_env = env_new()))
+ return PAM_SESSION_ERR;
+ if ((retval = pam_set_data(pamh, "ssh_env_handle", ssh_env,
+ env_cleanup)) != PAM_SUCCESS)
+ return retval;
while (fgets(parse, sizeof parse, pipe)) {
if (env_fp)
(void)fputs(parse, env_fp);
/*
* 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
* ssh_get_authentication_connection().
*/
if (strchr(parse, '=') && (env_end = strchr(parse, ';'))) {
*env_end = '\0';
/* pass to the application ... */
if (!((retval = pam_putenv(pamh, parse)) ==
- PAM_SUCCESS && putenv(parse) == 0)) {
+ PAM_SUCCESS)) {
(void)pclose(pipe);
if (env_fp)
(void)fclose(env_fp);
+ env_destroy(ssh_env);
return PAM_SERVICE_ERR;
}
+ env_put(ssh_env, parse);
}
}
if (env_fp)
(void)fclose(env_fp);
- retval = pclose(pipe);
- if (retval > 0) {
+ switch (retval = pclose(pipe)) {
+ case -1:
+ syslog(LOG_ERR, "%s: %s: %m", MODULE_NAME, PATH_SSH_AGENT);
+ env_destroy(ssh_env);
+ return PAM_SESSION_ERR;
+ case 0:
+ break;
+ case 127:
+ syslog(LOG_ERR, "%s: cannot execute %s", MODULE_NAME,
+ PATH_SSH_AGENT);
+ env_destroy(ssh_env);
+ return PAM_SESSION_ERR;
+ default:
syslog(LOG_ERR, "%s: %s exited with status %d",
MODULE_NAME, PATH_SSH_AGENT, WEXITSTATUS(retval));
- return PAM_SESSION_ERR;
- } else if (retval < 0) {
- syslog(LOG_ERR, "%s: %s: %m", MODULE_NAME, PATH_SSH_AGENT);
+ env_destroy(ssh_env);
return PAM_SESSION_ERR;
}
/* connect to the agent and hand off the private key */
if ((retval = pam_get_data(pamh, "ssh_private_key",
- (const void **)&key)) != PAM_SUCCESS)
- return retval;
- if ((retval = pam_get_data(pamh, "ssh_key_comment",
- (const void **)&comment)) != PAM_SUCCESS)
+ (const void **)&key)) != PAM_SUCCESS ||
+ (retval = pam_get_data(pamh, "ssh_key_comment",
+ (const void **)&comment)) != PAM_SUCCESS ||
+ (retval = env_commit(ssh_env)) != PAM_SUCCESS) {
+ env_destroy(ssh_env);
return retval;
+ }
if (!(ac = ssh_get_authentication_connection())) {
syslog(LOG_ERR, "%s: could not connect to agent",
MODULE_NAME);
+ env_destroy(ssh_env);
return PAM_SESSION_ERR;
}
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;
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