Adding upstream version 3.5.24.upstream/3.5.24

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 512 insertions, 0 deletions

diff --git a/src/smtp/smtp_sasl_glue.c b/src/smtp/smtp_sasl_glue.c
new file mode 100644
index 0000000..ef8e8c4
--- /dev/null
+++ b/src/smtp/smtp_sasl_glue.c
@@ -0,0 +1,512 @@
+/*++
+/* NAME
+/*	smtp_sasl_glue 3
+/* SUMMARY
+/*	Postfix SASL interface for SMTP client
+/* SYNOPSIS
+/*	#include smtp_sasl.h
+/*
+/*	void	smtp_sasl_initialize()
+/*
+/*	void	smtp_sasl_connect(session)
+/*	SMTP_SESSION *session;
+/*
+/*	void	smtp_sasl_start(session, sasl_opts_name, sasl_opts_val)
+/*	SMTP_SESSION *session;
+/*
+/*	int     smtp_sasl_passwd_lookup(session)
+/*	SMTP_SESSION *session;
+/*
+/*	int	smtp_sasl_authenticate(session, why)
+/*	SMTP_SESSION *session;
+/*	DSN_BUF *why;
+/*
+/*	void	smtp_sasl_cleanup(session)
+/*	SMTP_SESSION *session;
+/*
+/*	void	smtp_sasl_passivate(session, buf)
+/*	SMTP_SESSION *session;
+/*	VSTRING	*buf;
+/*
+/*	int	smtp_sasl_activate(session, buf)
+/*	SMTP_SESSION *session;
+/*	char	*buf;
+/* DESCRIPTION
+/*	smtp_sasl_initialize() initializes the SASL library. This
+/*	routine must be called once at process startup, before any
+/*	chroot operations.
+/*
+/*	smtp_sasl_connect() performs per-session initialization. This
+/*	routine must be called once at the start of each connection.
+/*
+/*	smtp_sasl_start() performs per-session initialization. This
+/*	routine must be called once per session before doing any SASL
+/*	authentication. The sasl_opts_name and sasl_opts_val parameters are
+/*	the postfix configuration parameters setting the security
+/*	policy of the SASL authentication.
+/*
+/*	smtp_sasl_passwd_lookup() looks up the username/password
+/*	for the current SMTP server. The result is zero in case
+/*	of failure, a long jump in case of error.
+/*
+/*	smtp_sasl_authenticate() implements the SASL authentication
+/*	dialog. The result is < 0 in case of protocol failure, zero in
+/*	case of unsuccessful authentication, > 0 in case of success.
+/*	The why argument is updated with a reason for failure.
+/*	This routine must be called only when smtp_sasl_passwd_lookup()
+/*	succeeds.
+/*
+/*	smtp_sasl_cleanup() cleans up. It must be called at the
+/*	end of every SMTP session that uses SASL authentication.
+/*	This routine is a noop for non-SASL sessions.
+/*
+/*	smtp_sasl_passivate() appends flattened SASL attributes to the
+/*	specified buffer. The SASL attributes are not destroyed.
+/*
+/*	smtp_sasl_activate() restores SASL attributes from the
+/*	specified buffer. The buffer is modified. A result < 0
+/*	means there was an error.
+/*
+/*	Arguments:
+/* .IP session
+/*	Session context.
+/* .IP mech_list
+/*	String of SASL mechanisms (separated by blanks)
+/* DIAGNOSTICS
+/*	All errors are fatal.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Original author:
+/*	Till Franke
+/*	SuSE Rhein/Main AG
+/*	65760 Eschborn, Germany
+/*
+/*	Adopted by:
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+ /*
+  * System library.
+  */
+#include <sys_defs.h>
+#include <stdlib.h>
+#include <string.h>
+
+ /*
+  * Utility library
+  */
+#include <msg.h>
+#include <mymalloc.h>
+#include <stringops.h>
+#include <split_at.h>
+
+ /*
+  * Global library
+  */
+#include <mail_params.h>
+#include <string_list.h>
+#include <maps.h>
+#include <mail_addr_find.h>
+#include <smtp_stream.h>
+
+ /*
+  * XSASL library.
+  */
+#include <xsasl.h>
+
+ /*
+  * Application-specific
+  */
+#include "smtp.h"
+#include "smtp_sasl.h"
+#include "smtp_sasl_auth_cache.h"
+
+#ifdef USE_SASL_AUTH
+
+ /*
+  * Per-host login/password information.
+  */
+static MAPS *smtp_sasl_passwd_map;
+
+ /*
+  * Supported SASL mechanisms.
+  */
+STRING_LIST *smtp_sasl_mechs;
+
+ /*
+  * SASL implementation handle.
+  */
+static XSASL_CLIENT_IMPL *smtp_sasl_impl;
+
+ /*
+  * The 535 SASL authentication failure cache.
+  */
+#ifdef HAVE_SASL_AUTH_CACHE
+static SMTP_SASL_AUTH_CACHE *smtp_sasl_auth_cache;
+
+#endif
+
+/* smtp_sasl_passwd_lookup - password lookup routine */
+
+int     smtp_sasl_passwd_lookup(SMTP_SESSION *session)
+{
+    const char *myname = "smtp_sasl_passwd_lookup";
+    SMTP_STATE *state = session->state;
+    SMTP_ITERATOR *iter = session->iterator;
+    const char *value;
+    char   *passwd;
+
+    /*
+     * Sanity check.
+     */
+    if (smtp_sasl_passwd_map == 0)
+	msg_panic("%s: passwd map not initialized", myname);
+
+    /*
+     * Look up the per-server password information. Try the hostname first,
+     * then try the destination.
+     * 
+     * XXX Instead of using nexthop (the intended destination) we use dest
+     * (either the intended destination, or a fall-back destination).
+     * 
+     * XXX SASL authentication currently depends on the host/domain but not on
+     * the TCP port. If the port is not :25, we should append it to the table
+     * lookup key. Code for this was briefly introduced into 2.2 snapshots,
+     * but didn't canonicalize the TCP port, and did not append the port to
+     * the MX hostname.
+     */
+    smtp_sasl_passwd_map->error = 0;
+    if ((smtp_mode
+	 && var_smtp_sender_auth && state->request->sender[0]
+	 && (value = mail_addr_find(smtp_sasl_passwd_map,
+				 state->request->sender, (char **) 0)) != 0)
+	|| (smtp_sasl_passwd_map->error == 0
+	    && (value = maps_find(smtp_sasl_passwd_map,
+				  STR(iter->host), 0)) != 0)
+	|| (smtp_sasl_passwd_map->error == 0
+	    && (value = maps_find(smtp_sasl_passwd_map,
+				  STR(iter->dest), 0)) != 0)) {
+	if (session->sasl_username)
+	    myfree(session->sasl_username);
+	session->sasl_username = mystrdup(value);
+	passwd = split_at(session->sasl_username, ':');
+	if (session->sasl_passwd)
+	    myfree(session->sasl_passwd);
+	session->sasl_passwd = mystrdup(passwd ? passwd : "");
+	if (msg_verbose)
+	    msg_info("%s: host `%s' user `%s' pass `%s'",
+		     myname, STR(iter->host),
+		     session->sasl_username, session->sasl_passwd);
+	return (1);
+    } else if (smtp_sasl_passwd_map->error) {
+	msg_warn("%s: %s lookup error",
+		 state->request->queue_id, smtp_sasl_passwd_map->title);
+	vstream_longjmp(session->stream, SMTP_ERR_DATA);
+    } else {
+	if (msg_verbose)
+	    msg_info("%s: no auth info found (sender=`%s', host=`%s')",
+		     myname, state->request->sender, STR(iter->host));
+	return (0);
+    }
+}
+
+/* smtp_sasl_initialize - per-process initialization (pre jail) */
+
+void    smtp_sasl_initialize(void)
+{
+
+    /*
+     * Sanity check.
+     */
+    if (smtp_sasl_passwd_map || smtp_sasl_impl)
+	msg_panic("smtp_sasl_initialize: repeated call");
+    if (*var_smtp_sasl_passwd == 0)
+	msg_fatal("specify a password table via the `%s' configuration parameter",
+		  VAR_LMTP_SMTP(SASL_PASSWD));
+
+    /*
+     * Open the per-host password table and initialize the SASL library. Use
+     * shared locks for reading, just in case someone updates the table.
+     */
+    smtp_sasl_passwd_map = maps_create(VAR_LMTP_SMTP(SASL_PASSWD),
+				       var_smtp_sasl_passwd,
+				       DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX
+				       | DICT_FLAG_UTF8_REQUEST);
+    if ((smtp_sasl_impl = xsasl_client_init(var_smtp_sasl_type,
+					    var_smtp_sasl_path)) == 0)
+	msg_fatal("SASL library initialization");
+
+    /*
+     * Initialize optional supported mechanism matchlist
+     */
+    if (*var_smtp_sasl_mechs)
+	smtp_sasl_mechs = string_list_init(VAR_SMTP_SASL_MECHS,
+					   MATCH_FLAG_NONE,
+					   var_smtp_sasl_mechs);
+
+    /*
+     * Initialize the 535 SASL authentication failure cache.
+     */
+    if (*var_smtp_sasl_auth_cache_name) {
+#ifdef HAVE_SASL_AUTH_CACHE
+	smtp_sasl_auth_cache =
+	    smtp_sasl_auth_cache_init(var_smtp_sasl_auth_cache_name,
+				      var_smtp_sasl_auth_cache_time);
+#else
+	msg_warn("not compiled with TLS support -- "
+	    "ignoring the %s setting", VAR_LMTP_SMTP(SASL_AUTH_CACHE_NAME));
+#endif
+    }
+}
+
+/* smtp_sasl_connect - per-session client initialization */
+
+void    smtp_sasl_connect(SMTP_SESSION *session)
+{
+
+    /*
+     * This initialization happens whenever we instantiate an SMTP session
+     * object. We don't instantiate a SASL client until we actually need one.
+     */
+    session->sasl_mechanism_list = 0;
+    session->sasl_username = 0;
+    session->sasl_passwd = 0;
+    session->sasl_client = 0;
+    session->sasl_reply = 0;
+}
+
+/* smtp_sasl_start - per-session SASL initialization */
+
+void    smtp_sasl_start(SMTP_SESSION *session, const char *sasl_opts_name,
+			        const char *sasl_opts_val)
+{
+    XSASL_CLIENT_CREATE_ARGS create_args;
+    SMTP_ITERATOR *iter = session->iterator;
+
+    if (msg_verbose)
+	msg_info("starting new SASL client");
+    if ((session->sasl_client =
+	 XSASL_CLIENT_CREATE(smtp_sasl_impl, &create_args,
+			     stream = session->stream,
+			     service = var_procname,
+			     server_name = STR(iter->host),
+			     security_options = sasl_opts_val)) == 0)
+	msg_fatal("SASL per-connection initialization failed");
+    session->sasl_reply = vstring_alloc(20);
+}
+
+/* smtp_sasl_authenticate - run authentication protocol */
+
+int     smtp_sasl_authenticate(SMTP_SESSION *session, DSN_BUF *why)
+{
+    const char *myname = "smtp_sasl_authenticate";
+    SMTP_ITERATOR *iter = session->iterator;
+    SMTP_RESP *resp;
+    const char *mechanism;
+    int     result;
+    char   *line;
+    int     steps = 0;
+
+    /*
+     * Sanity check.
+     */
+    if (session->sasl_mechanism_list == 0)
+	msg_panic("%s: no mechanism list", myname);
+
+    if (msg_verbose)
+	msg_info("%s: %s: SASL mechanisms %s",
+		 myname, session->namaddrport, session->sasl_mechanism_list);
+
+    /*
+     * Avoid repeated login failures after a recent 535 error.
+     */
+#ifdef HAVE_SASL_AUTH_CACHE
+    if (smtp_sasl_auth_cache
+	&& smtp_sasl_auth_cache_find(smtp_sasl_auth_cache, session)) {
+	char   *resp_dsn = smtp_sasl_auth_cache_dsn(smtp_sasl_auth_cache);
+	char   *resp_str = smtp_sasl_auth_cache_text(smtp_sasl_auth_cache);
+
+	if (var_smtp_sasl_auth_soft_bounce && resp_dsn[0] == '5')
+	    resp_dsn[0] = '4';
+	dsb_update(why, resp_dsn, DSB_DEF_ACTION, DSB_MTYPE_DNS,
+		   STR(iter->host), var_procname, resp_str,
+		   "SASL [CACHED] authentication failed; server %s said: %s",
+		   STR(iter->host), resp_str);
+	return (0);
+    }
+#endif
+
+    /*
+     * Start the client side authentication protocol.
+     */
+    result = xsasl_client_first(session->sasl_client,
+				session->sasl_mechanism_list,
+				session->sasl_username,
+				session->sasl_passwd,
+				&mechanism, session->sasl_reply);
+    if (result != XSASL_AUTH_OK) {
+	dsb_update(why, "4.7.0", DSB_DEF_ACTION, DSB_SKIP_RMTA,
+		   DSB_DTYPE_SASL, STR(session->sasl_reply),
+		   "SASL authentication failed; "
+		   "cannot authenticate to server %s: %s",
+		   session->namaddr, STR(session->sasl_reply));
+	return (-1);
+    }
+    /*-
+     * Send the AUTH command and the optional initial client response.
+     *
+     * https://tools.ietf.org/html/rfc4954#page-4
+     * Note that the AUTH command is still subject to the line length
+     * limitations defined in [SMTP].  If use of the initial response argument
+     * would cause the AUTH command to exceed this length, the client MUST NOT
+     * use the initial response parameter...
+     *
+     * https://tools.ietf.org/html/rfc5321#section-4.5.3.1.4
+     * The maximum total length of a command line including the command word
+     * and the <CRLF> is 512 octets.
+     *
+     * Defer the initial response if the resulting command exceeds the limit.
+     */
+    if (LEN(session->sasl_reply) > 0
+	&& strlen(mechanism) + LEN(session->sasl_reply) + 8 <= 512) {
+	smtp_chat_cmd(session, "AUTH %s %s", mechanism,
+		      STR(session->sasl_reply));
+	VSTRING_RESET(session->sasl_reply);	/* no deferred initial reply */
+    } else {
+	smtp_chat_cmd(session, "AUTH %s", mechanism);
+    }
+
+    /*
+     * Step through the authentication protocol until the server tells us
+     * that we are done.  If session->sasl_reply is non-empty we have a
+     * deferred initial reply and expect an empty initial challenge from the
+     * server. If the server's initial challenge is non-empty we have a SASL
+     * protocol violation with both sides wanting to go first.
+     */
+    while ((resp = smtp_chat_resp(session))->code / 100 == 3) {
+
+	/*
+	 * Sanity check.
+	 */
+	if (++steps > 100) {
+	    dsb_simple(why, "4.3.0", "SASL authentication failed; "
+		       "authentication protocol loop with server %s",
+		       session->namaddr);
+	    return (-1);
+	}
+
+	/*
+	 * Process a server challenge.
+	 */
+	line = resp->str;
+	(void) mystrtok(&line, "- \t\n");	/* skip over result code */
+
+	if (LEN(session->sasl_reply) > 0) {
+
+	    /*
+	     * Deferred initial response, the server challenge must be empty.
+	     * Cleared after actual transmission to the server.
+	     */
+	    if (*line) {
+		dsb_update(why, "4.7.0", DSB_DEF_ACTION,
+			   DSB_SKIP_RMTA, DSB_DTYPE_SASL, "protocol error",
+			   "SASL authentication failed; non-empty initial "
+			   "%s challenge from server %s: %s", mechanism,
+			   session->namaddr, STR(session->sasl_reply));
+		return (-1);
+	    }
+	} else {
+	    result = xsasl_client_next(session->sasl_client, line,
+				       session->sasl_reply);
+	    if (result != XSASL_AUTH_OK) {
+		dsb_update(why, "4.7.0", DSB_DEF_ACTION,	/* Fix 200512 */
+		    DSB_SKIP_RMTA, DSB_DTYPE_SASL, STR(session->sasl_reply),
+			   "SASL authentication failed; "
+			   "cannot authenticate to server %s: %s",
+			   session->namaddr, STR(session->sasl_reply));
+		return (-1);			/* Fix 200512 */
+	    }
+	}
+
+	/*
+	 * Send a client response.
+	 */
+	smtp_chat_cmd(session, "%s", STR(session->sasl_reply));
+	VSTRING_RESET(session->sasl_reply);	/* clear initial reply */
+    }
+
+    /*
+     * We completed the authentication protocol.
+     */
+    if (resp->code / 100 != 2) {
+#ifdef HAVE_SASL_AUTH_CACHE
+	/* Update the 535 authentication failure cache. */
+	if (smtp_sasl_auth_cache && resp->code == 535)
+	    smtp_sasl_auth_cache_store(smtp_sasl_auth_cache, session, resp);
+#endif
+	if (var_smtp_sasl_auth_soft_bounce && resp->code / 100 == 5)
+	    STR(resp->dsn_buf)[0] = '4';
+	dsb_update(why, resp->dsn, DSB_DEF_ACTION,
+		   DSB_MTYPE_DNS, STR(iter->host),
+		   var_procname, resp->str,
+		   "SASL authentication failed; server %s said: %s",
+		   session->namaddr, resp->str);
+	return (0);
+    }
+    return (1);
+}
+
+/* smtp_sasl_cleanup - per-session cleanup */
+
+void    smtp_sasl_cleanup(SMTP_SESSION *session)
+{
+    if (session->sasl_username) {
+	myfree(session->sasl_username);
+	session->sasl_username = 0;
+    }
+    if (session->sasl_passwd) {
+	myfree(session->sasl_passwd);
+	session->sasl_passwd = 0;
+    }
+    if (session->sasl_mechanism_list) {
+	/* allocated in smtp_sasl_helo_auth */
+	myfree(session->sasl_mechanism_list);
+	session->sasl_mechanism_list = 0;
+    }
+    if (session->sasl_client) {
+	if (msg_verbose)
+	    msg_info("disposing SASL state information");
+	xsasl_client_free(session->sasl_client);
+	session->sasl_client = 0;
+    }
+    if (session->sasl_reply) {
+	vstring_free(session->sasl_reply);
+	session->sasl_reply = 0;
+    }
+}
+
+/* smtp_sasl_passivate - append serialized SASL attributes */
+
+void    smtp_sasl_passivate(SMTP_SESSION *session, VSTRING *buf)
+{
+}
+
+/* smtp_sasl_activate - de-serialize SASL attributes */
+
+int     smtp_sasl_activate(SMTP_SESSION *session, char *buf)
+{
+    return (0);
+}
+
+#endif