- Removed most of the pam code into its own file auth-pam.[ch]. This

   cleaned up sshd.c up significantly.
 - Several other cleanups

1 files changed, 239 insertions, 0 deletions

diff --git a/auth-pam.c b/auth-pam.c
new file mode 100644
index 00000000..8d872689
--- /dev/null
+++ b/auth-pam.c
@@ -0,0 +1,239 @@
+/*
+ * Author: Damien Miller
+ * Copyright (c) 1999 Damien Miller <djm@mindrot.org>
+ *                    All rights reserved
+ * Created: Thursday December 30 1999
+ * PAM authentication and session management code.
+ */
+
+#include "includes.h"
+
+#ifdef USE_PAM
+#include "ssh.h"
+#include "xmalloc.h"
+#include "servconf.h"
+
+RCSID("$Id: auth-pam.c,v 1.1 1999/12/30 04:11:25 damien Exp $");
+
+/* Callbacks */
+static int pamconv(int num_msg, const struct pam_message **msg,
+	  struct pam_response **resp, void *appdata_ptr);
+void pam_cleanup_proc(void *context);
+
+/* module-local variables */
+static struct pam_conv conv = {
+	pamconv,
+	NULL
+};
+static struct pam_handle_t *pamh = NULL;
+static const char *pampasswd = NULL;
+static char *pamconv_msg = NULL;
+
+/* PAM conversation function. This is really a kludge to get the password */
+/* into PAM and to pick up any messages generated by PAM into pamconv_msg */
+static int pamconv(int num_msg, const struct pam_message **msg,
+	struct pam_response **resp, void *appdata_ptr)
+{
+	struct pam_response *reply;
+	int count;
+	size_t msg_len;
+	char *p;
+
+	/* 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++) {
+		switch (msg[count]->msg_style) {
+			case PAM_PROMPT_ECHO_OFF:
+				if (pampasswd == NULL) {
+					free(reply);
+					return PAM_CONV_ERR;
+				}
+				reply[count].resp_retcode = PAM_SUCCESS;
+				reply[count].resp = xstrdup(pampasswd);
+				break;
+
+			case PAM_TEXT_INFO:
+				reply[count].resp_retcode = PAM_SUCCESS;
+				reply[count].resp = xstrdup("");
+
+				if (msg[count]->msg == NULL)
+					break;
+
+				debug("Adding PAM message: %s", msg[count]->msg);
+
+				msg_len = strlen(msg[count]->msg);
+				if (pamconv_msg) {
+					size_t n = strlen(pamconv_msg);
+					pamconv_msg = xrealloc(pamconv_msg, n + msg_len + 2);
+					p = pamconv_msg + n;
+				} else {
+					pamconv_msg = p = xmalloc(msg_len + 2);
+				}
+				memcpy(p, msg[count]->msg, msg_len);
+				p[msg_len] = '\n';
+				p[msg_len + 1] = '\0';
+				break;
+
+			case PAM_PROMPT_ECHO_ON:
+			case PAM_ERROR_MSG:
+			default:
+				free(reply);
+				return PAM_CONV_ERR;
+		}
+	}
+
+	*resp = reply;
+
+	return PAM_SUCCESS;
+}
+
+/* Called at exit to cleanly shutdown PAM */
+void pam_cleanup_proc(void *context)
+{
+	int pam_retval;
+
+	if (pamh != NULL)
+	{
+		pam_retval = pam_close_session((pam_handle_t *)pamh, 0);
+		if (pam_retval != PAM_SUCCESS) {
+			log("Cannot close PAM session: %.200s", 
+			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+		}
+
+		pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_DELETE_CRED);
+		if (pam_retval != PAM_SUCCESS) {
+			log("Cannot delete credentials: %.200s", 
+			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+		}
+
+		pam_retval = pam_end((pam_handle_t *)pamh, pam_retval);
+		if (pam_retval != PAM_SUCCESS) {
+			log("Cannot release PAM authentication: %.200s", 
+			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+		}
+	}
+}
+
+/* Attempt password authentation using PAM */
+int auth_pam_password(struct passwd *pw, const char *password)
+{
+	extern ServerOptions options;
+	int pam_retval;
+
+	/* deny if no user. */
+	if (pw == NULL)
+		return 0;
+	if (pw->pw_uid == 0 && options.permit_root_login == 2)
+		return 0;
+	if (*password == '\0' && options.permit_empty_passwd == 0)
+		return 0;
+
+	pampasswd = password;
+	
+	pam_retval = pam_authenticate((pam_handle_t *)pamh, 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: %s", 
+			pw->pw_name, PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+		return 0;
+	}
+}
+
+/* Do account management using PAM */
+int do_pam_account(char *username, char *remote_user)
+{
+	int pam_retval;
+
+	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
+	pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST, 
+		get_canonical_hostname());
+	if (pam_retval != PAM_SUCCESS) {
+		fatal("PAM set rhost failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+	}
+
+	if (remote_user != NULL) {
+		debug("PAM setting ruser to \"%.200s\"", remote_user);
+		pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user);
+		if (pam_retval != PAM_SUCCESS) {
+			fatal("PAM set ruser failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+		}
+	}
+
+	pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0);
+	if (pam_retval != PAM_SUCCESS) {
+		log("PAM rejected by account configuration: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+		return(0);
+	}
+	
+	return(1);
+}
+
+/* Do PAM-specific session initialisation */
+void do_pam_session(char *username, char *ttyname)
+{
+	int pam_retval;
+
+	if (ttyname != NULL) {
+		debug("PAM setting tty to \"%.200s\"", ttyname);
+		pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_TTY, ttyname);
+		if (pam_retval != PAM_SUCCESS)
+			fatal("PAM set tty failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+	}
+
+	pam_retval = pam_open_session((pam_handle_t *)pamh, 0);
+	if (pam_retval != PAM_SUCCESS)
+		fatal("PAM session setup failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+}
+
+/* Set PAM credentials */ 
+void do_pam_setcred()
+{
+	int pam_retval;
+ 
+	debug("PAM establishing creds");
+	pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_ESTABLISH_CRED);
+	if (pam_retval != PAM_SUCCESS)
+		fatal("PAM setcred failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+}
+
+/* Cleanly shutdown PAM */
+void finish_pam(void)
+{
+	pam_cleanup_proc(NULL);
+	fatal_remove_cleanup(&pam_cleanup_proc, NULL);
+}
+
+/* Start PAM authentication for specified account */
+void start_pam(struct passwd *pw)
+{
+	int pam_retval;
+
+	debug("Starting up PAM with username \"%.200s\"", pw->pw_name);
+
+	pam_retval = pam_start("sshd", pw->pw_name, &conv, (pam_handle_t**)&pamh);
+	if (pam_retval != PAM_SUCCESS)
+		fatal("PAM initialisation failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+
+	fatal_add_cleanup(&pam_cleanup_proc, NULL);
+}
+
+/* Return list of PAM enviornment strings */
+char **fetch_pam_environment(void)
+{
+	return(pam_getenvlist((pam_handle_t *)pamh));
+}
+
+/* Print any messages that have been generated during authentication */
+/* or account checking to stderr */
+void print_pam_messages(void)
+{
+	if (pamconv_msg != NULL)
+		fprintf(stderr, pamconv_msg);
+}
+
+#endif /* USE_PAM */