Adding upstream version 3.4.23.upstream/3.4.23upstream

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

14 files changed, 3221 insertions, 0 deletions

diff --git a/src/xsasl/.indent.pro b/src/xsasl/.indent.pro
new file mode 120000
index 0000000..5c837ec
--- /dev/null
+++ b/src/xsasl/.indent.pro
@@ -0,0 +1 @@
+../../.indent.pro
\ No newline at end of file
diff --git a/src/xsasl/Makefile.in b/src/xsasl/Makefile.in
new file mode 100644
index 0000000..ad48302
--- /dev/null
+++ b/src/xsasl/Makefile.in
@@ -0,0 +1,165 @@
+SHELL	= /bin/sh
+SRCS	= xsasl_server.c xsasl_cyrus_server.c xsasl_cyrus_log.c \
+	xsasl_cyrus_security.c xsasl_client.c xsasl_cyrus_client.c \
+	xsasl_dovecot_server.c
+OBJS	= xsasl_server.o xsasl_cyrus_server.o xsasl_cyrus_log.o \
+	xsasl_cyrus_security.o xsasl_client.o xsasl_cyrus_client.o \
+	xsasl_dovecot_server.o
+HDRS	= xsasl.h
+TESTSRC	= 
+DEFS	= -I. -I$(INC_DIR) -D$(SYSTYPE)
+CFLAGS	= $(DEBUG) $(OPT) $(DEFS)
+INCL	=
+LIB	= libxsasl.a
+TESTPROG= 
+
+LIBS	= ../../lib/lib$(LIB_PERFIX)global$(LIB_SUFFIX) \
+	../../lib/lib$(LIB_PERFIX)util$(LIB_SUFFIX)
+LIB_DIR	= ../../lib
+INC_DIR	= ../../include
+MAKES	=
+
+.c.o:;	$(CC) $(CFLAGS) -c $*.c
+
+all: $(LIB)
+
+$(OBJS): ../../conf/makedefs.out
+
+Makefile: Makefile.in
+	cat ../../conf/makedefs.out $? >$@
+
+test:	$(TESTPROG)
+
+tests:
+
+root_tests:
+
+$(LIB):	$(OBJS)
+	$(_AR) $(ARFL) $(LIB) $?
+	$(_RANLIB) $(LIB)
+
+$(LIB_DIR)/$(LIB): $(LIB)
+	cp $(LIB) $(LIB_DIR)
+	$(_RANLIB) $(LIB_DIR)/$(LIB)
+
+update: $(LIB_DIR)/$(LIB) $(HDRS)
+	-for i in $(HDRS); \
+	do \
+	  cmp -s $$i $(INC_DIR)/$$i 2>/dev/null || cp $$i $(INC_DIR); \
+	done
+	cd $(INC_DIR); chmod 644 $(HDRS)
+
+printfck: $(OBJS) $(PROG)
+	rm -rf printfck
+	mkdir printfck
+	cp *.h printfck
+	sed '1,/^# do not edit/!d' Makefile >printfck/Makefile
+	set -e; for i in *.c; do printfck -f .printfck $$i >printfck/$$i; done
+	cd printfck; make "INC_DIR=../../../include" `cd ..; ls *.o`
+
+lint:
+	lint $(DEFS) $(SRCS) $(LINTFIX)
+
+clean:
+	rm -f *.o $(LIB) *core $(TESTPROG) junk
+	rm -rf printfck
+
+tidy:	clean
+
+foo: $(LIB) $(LIBS)
+	mv $@.o junk
+	$(CC) $(CFLAGS) -DTEST -o $@ $@.c $(LIB) $(LIBS) $(SYSLIBS)
+	mv junk $@.o
+
+depend: $(MAKES)
+	(sed '1,/^# do not edit/!d' Makefile.in; \
+	set -e; for i in [a-z][a-z0-9]*.c; do \
+	    $(CC) -E $(DEFS) $(INCL) $$i | grep -v '[<>]' | sed -n -e '/^# *1 *"\([^"]*\)".*/{' \
+	    -e 's//'`echo $$i|sed 's/c$$/o/'`': \1/' \
+	    -e 's/o: \.\//o: /' -e p -e '}' ; \
+	done | LANG=C sort -u) | grep -v '[.][o][:][ ][/]' >$$$$ && mv $$$$ Makefile.in
+	@$(EXPORT) make -f Makefile.in Makefile 1>&2
+
+# do not edit below this line - it is generated by 'make depend'
+xsasl_client.o: ../../include/argv.h
+xsasl_client.o: ../../include/check_arg.h
+xsasl_client.o: ../../include/msg.h
+xsasl_client.o: ../../include/mymalloc.h
+xsasl_client.o: ../../include/sys_defs.h
+xsasl_client.o: ../../include/vbuf.h
+xsasl_client.o: ../../include/vstream.h
+xsasl_client.o: ../../include/vstring.h
+xsasl_client.o: xsasl.h
+xsasl_client.o: xsasl_client.c
+xsasl_client.o: xsasl_cyrus.h
+xsasl_cyrus_client.o: ../../include/argv.h
+xsasl_cyrus_client.o: ../../include/check_arg.h
+xsasl_cyrus_client.o: ../../include/mail_params.h
+xsasl_cyrus_client.o: ../../include/msg.h
+xsasl_cyrus_client.o: ../../include/mymalloc.h
+xsasl_cyrus_client.o: ../../include/stringops.h
+xsasl_cyrus_client.o: ../../include/sys_defs.h
+xsasl_cyrus_client.o: ../../include/vbuf.h
+xsasl_cyrus_client.o: ../../include/vstream.h
+xsasl_cyrus_client.o: ../../include/vstring.h
+xsasl_cyrus_client.o: xsasl.h
+xsasl_cyrus_client.o: xsasl_cyrus.h
+xsasl_cyrus_client.o: xsasl_cyrus_client.c
+xsasl_cyrus_client.o: xsasl_cyrus_common.h
+xsasl_cyrus_log.o: ../../include/msg.h
+xsasl_cyrus_log.o: ../../include/sys_defs.h
+xsasl_cyrus_log.o: xsasl_cyrus_common.h
+xsasl_cyrus_log.o: xsasl_cyrus_log.c
+xsasl_cyrus_security.o: ../../include/check_arg.h
+xsasl_cyrus_security.o: ../../include/name_mask.h
+xsasl_cyrus_security.o: ../../include/sys_defs.h
+xsasl_cyrus_security.o: ../../include/vbuf.h
+xsasl_cyrus_security.o: ../../include/vstring.h
+xsasl_cyrus_security.o: xsasl_cyrus_common.h
+xsasl_cyrus_security.o: xsasl_cyrus_security.c
+xsasl_cyrus_server.o: ../../include/argv.h
+xsasl_cyrus_server.o: ../../include/check_arg.h
+xsasl_cyrus_server.o: ../../include/mail_params.h
+xsasl_cyrus_server.o: ../../include/msg.h
+xsasl_cyrus_server.o: ../../include/mymalloc.h
+xsasl_cyrus_server.o: ../../include/name_mask.h
+xsasl_cyrus_server.o: ../../include/stringops.h
+xsasl_cyrus_server.o: ../../include/sys_defs.h
+xsasl_cyrus_server.o: ../../include/vbuf.h
+xsasl_cyrus_server.o: ../../include/vstream.h
+xsasl_cyrus_server.o: ../../include/vstring.h
+xsasl_cyrus_server.o: xsasl.h
+xsasl_cyrus_server.o: xsasl_cyrus.h
+xsasl_cyrus_server.o: xsasl_cyrus_common.h
+xsasl_cyrus_server.o: xsasl_cyrus_server.c
+xsasl_dovecot_server.o: ../../include/argv.h
+xsasl_dovecot_server.o: ../../include/check_arg.h
+xsasl_dovecot_server.o: ../../include/connect.h
+xsasl_dovecot_server.o: ../../include/iostuff.h
+xsasl_dovecot_server.o: ../../include/mail_params.h
+xsasl_dovecot_server.o: ../../include/msg.h
+xsasl_dovecot_server.o: ../../include/myaddrinfo.h
+xsasl_dovecot_server.o: ../../include/mymalloc.h
+xsasl_dovecot_server.o: ../../include/name_mask.h
+xsasl_dovecot_server.o: ../../include/split_at.h
+xsasl_dovecot_server.o: ../../include/stringops.h
+xsasl_dovecot_server.o: ../../include/sys_defs.h
+xsasl_dovecot_server.o: ../../include/vbuf.h
+xsasl_dovecot_server.o: ../../include/vstream.h
+xsasl_dovecot_server.o: ../../include/vstring.h
+xsasl_dovecot_server.o: ../../include/vstring_vstream.h
+xsasl_dovecot_server.o: xsasl.h
+xsasl_dovecot_server.o: xsasl_dovecot.h
+xsasl_dovecot_server.o: xsasl_dovecot_server.c
+xsasl_server.o: ../../include/argv.h
+xsasl_server.o: ../../include/check_arg.h
+xsasl_server.o: ../../include/msg.h
+xsasl_server.o: ../../include/mymalloc.h
+xsasl_server.o: ../../include/sys_defs.h
+xsasl_server.o: ../../include/vbuf.h
+xsasl_server.o: ../../include/vstream.h
+xsasl_server.o: ../../include/vstring.h
+xsasl_server.o: xsasl.h
+xsasl_server.o: xsasl_cyrus.h
+xsasl_server.o: xsasl_dovecot.h
+xsasl_server.o: xsasl_server.c
diff --git a/src/xsasl/README b/src/xsasl/README
new file mode 100644
index 0000000..d1b2f5a
--- /dev/null
+++ b/src/xsasl/README
@@ -0,0 +1,109 @@
+Purpose of this document
+========================
+
+This document describes how to add your own SASL implementation to
+Postfix.  You don't have to provide both the server and client side.
+You can provide just one and omit the other. The examples below
+assume you do both.
+
+The plug-in API is described in cyrus_server.c and cyrus_client.c.
+It was unavoidably contaminated^h^h^h^h^h^h^h^h^h^h^h^hinfluenced
+by Cyrus SASL and may need revision as other implementations are
+added.
+
+For an example of how the plug-in interface is implemented, have a
+look at the xsasl/xsasl_cyrus_client.c and xsasl/xsasl_cyrus_server.c.
+
+Configuration features
+======================
+
+There are two configuration parameters that allow you to pass
+information from main.cf into the plug_in:
+
+    smtpd_sasl_path, smtpd_sasl_security_options
+    smtp_sasl_path, smtp_sasl_security_options
+    lmtp_sasl_path, lmtp_sasl_security_options
+
+As usual, newline characters are removed from multi-line parameter
+values, and $name is expanded recursively.  The parameter values
+are passed to the plug-in without any further processing. The
+following restrictions are imposed by the main.cf file parser:
+
+- parameter values never contain newlines,
+
+- parameter values never start or end with whitespace characters.
+
+The _path parameter value is passed only once during process
+initialization (i.e. it is a class variable). The path typically
+specifies the location of a configuration file or rendez-vous point.
+The _security_options parameter value is passed each time SASL is
+turned on for a connection (i.e. it is an instance variable).  The
+options may depend on whether or not TLS encryption is turned on.
+Remember that one Postfix process may perform up to 100 mail
+transactions during its life time. Things that happen in one
+transaction must not affect later transactions.
+
+Adding Postfix support for your own SASL implementation
+=======================================================
+
+To add your own SASL implementation, say, FOOBAR:
+
+- Copy xsasl/xsasl_cyrus.h to xsasl/xsasl_foobar.h and replace
+  CYRUS by FOOBAR:
+
+ #if defined(USE_SASL_AUTH) && defined(USE_FOOBAR_SASL)
+  /*
+   * SASL protocol interface
+   */
+ #define XSASL_TYPE_FOOBAR "foobar"
+ extern XSASL_SERVER_IMPL *xsasl_foobar_server_init(const char *, const char *);
+ extern XSASL_CLIENT_IMPL *xsasl_foobar_client_init(const char *, const char *);
+ #endif
+
+- Edit xsasl/xsasl_server.c, add your #include <xsasl_foobar.h> line
+  under #include <xsasl_cyrus.h> at the top, and add your initialization
+  function in the table at the bottom as shown below:
+
+  static XSASL_SERVER_IMPL_INFO server_impl_info[] = {
+  #ifdef XSASL_TYPE_CYRUS
+      XSASL_TYPE_CYRUS, xsasl_cyrus_server_init,
+  #endif
+  #ifdef XSASL_TYPE_FOOBAR
+      XSASL_TYPE_FOOBAR, xsasl_foobar_server_init,
+  #endif
+      0,
+  };
+
+- Repeat the (almost) same procedure for xsasl/xsasl_client.c.
+
+- Create your own xsasl/xsasl_foobar_{client,server}.c and support
+  files. Perhaps it's convenient to copy the cyrus files, rip out
+  the function bodies, and replace CYRUS by FOOBAR.
+
+- List your source files in Makefile.in. Don't forget to do "make
+  depend" after you do "make makefiles" in the step that follows
+  after this one.
+
+  SRCS    = xsasl_server.c xsasl_cyrus_server.c xsasl_cyrus_log.c \
+          xsasl_cyrus_security.c xsasl_client.c xsasl_cyrus_client.c \
+          xsasl_foobar_client.c xsasl_foobar_server.c
+  OBJS    = xsasl_server.o xsasl_cyrus_server.o xsasl_cyrus_log.o \
+          xsasl_cyrus_security.o xsasl_client.o xsasl_cyrus_client.o \
+          xsasl_foobar_client.o xsasl_foobar_server.o
+
+- Create the Postfix makefiles from the top-level directory:
+
+  % make makefiles CCARGS='-DUSE_SASL_AUTH -DUSE_FOOBAR_SASL \
+      -DDEF_CLIENT_SASL_TYPE=\"foobar\" -DDEF_SERVER_SASL_TYPE=\"foobar\" \
+      -I/some/where/include' AUXLIBS='-L/some/where/lib -lfoobar'
+
+  Yes, you can have different default SASL implementation types for
+  the client and server plug-ins.
+
+  Of course you don't have to override the default SASL implementation
+  type; it is shown here as an example.
+  
+
+- Don't forget to do "make depend" in the xsasl directory.
+
+- Document your build and configuration with a README document.
diff --git a/src/xsasl/xsasl.h b/src/xsasl/xsasl.h
new file mode 100644
index 0000000..b494d7e
--- /dev/null
+++ b/src/xsasl/xsasl.h
@@ -0,0 +1,146 @@
+#ifndef _XSASL_H_INCLUDED_
+#define _XSASL_H_INCLUDED_
+
+/*++
+/* NAME
+/*	xsasl 3h
+/* SUMMARY
+/*	Postfix SASL plug-in interface
+/* SYNOPSIS
+/*	#include <xsasl.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * Utility library.
+  */
+#include <argv.h>
+#include <vstream.h>
+#include <vstring.h>
+
+ /*
+  * Generic server object. Specific instances extend this with their own
+  * private data.
+  */
+typedef struct XSASL_SERVER {
+    void    (*free) (struct XSASL_SERVER *);
+    int     (*first) (struct XSASL_SERVER *, const char *, const char *, VSTRING *);
+    int     (*next) (struct XSASL_SERVER *, const char *, VSTRING *);
+    const char *(*get_mechanism_list) (struct XSASL_SERVER *);
+    const char *(*get_username) (struct XSASL_SERVER *);
+} XSASL_SERVER;
+
+#define xsasl_server_free(server) (server)->free(server)
+#define xsasl_server_first(server, method, init_resp, reply) \
+	(server)->first((server), (method), (init_resp), (reply))
+#define xsasl_server_next(server, request, reply) \
+	(server)->next((server), (request), (reply))
+#define xsasl_server_get_mechanism_list(server) \
+	(server)->get_mechanism_list((server))
+#define xsasl_server_get_username(server) \
+	(server)->get_username((server))
+
+ /*
+  * Generic server implementation. Specific instances extend this with their
+  * own private data.
+  */
+typedef struct XSASL_SERVER_CREATE_ARGS {
+    VSTREAM *stream;
+    int     addr_family;
+    const char *server_addr;
+    const char *server_port;
+    const char *client_addr;
+    const char *client_port;
+    const char *service;
+    const char *user_realm;
+    const char *security_options;
+    int     tls_flag;
+} XSASL_SERVER_CREATE_ARGS;
+
+typedef struct XSASL_SERVER_IMPL {
+    XSASL_SERVER *(*create) (struct XSASL_SERVER_IMPL *, XSASL_SERVER_CREATE_ARGS *);
+    void    (*done) (struct XSASL_SERVER_IMPL *);
+} XSASL_SERVER_IMPL;
+
+extern XSASL_SERVER_IMPL *xsasl_server_init(const char *, const char *);
+extern ARGV *xsasl_server_types(void);
+
+#define xsasl_server_create(impl, args) \
+	(impl)->create((impl), (args))
+#define XSASL_SERVER_CREATE(impl, args, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10) \
+	xsasl_server_create((impl), (((args)->a1), ((args)->a2), ((args)->a3), \
+	((args)->a4), ((args)->a5), ((args)->a6), ((args)->a7), ((args)->a8), \
+	((args)->a9), ((args)->a10), (args)))
+#define xsasl_server_done(impl) (impl)->done((impl));
+
+ /*
+  * Generic client object. Specific instances extend this with their own
+  * private data.
+  */
+typedef struct XSASL_CLIENT {
+    void    (*free) (struct XSASL_CLIENT *);
+    int     (*first) (struct XSASL_CLIENT *, const char *, const char *, const char *, const char **, VSTRING *);
+    int     (*next) (struct XSASL_CLIENT *, const char *, VSTRING *);
+} XSASL_CLIENT;
+
+#define xsasl_client_free(client) (client)->free(client)
+#define xsasl_client_first(client, server, method, user, pass, init_resp) \
+	(client)->first((client), (server), (method), (user), (pass), (init_resp))
+#define xsasl_client_next(client, request, reply) \
+	(client)->next((client), (request), (reply))
+#define xsasl_client_set_password(client, user, pass) \
+	(client)->set_password((client), (user), (pass))
+
+ /*
+  * Generic client implementation. Specific instances extend this with their
+  * own private data.
+  */
+typedef struct XSASL_CLIENT_CREATE_ARGS {
+    VSTREAM *stream;
+    const char *service;
+    const char *server_name;
+    const char *security_options;
+} XSASL_CLIENT_CREATE_ARGS;
+
+typedef struct XSASL_CLIENT_IMPL {
+    XSASL_CLIENT *(*create) (struct XSASL_CLIENT_IMPL *, XSASL_CLIENT_CREATE_ARGS *);
+    void    (*done) (struct XSASL_CLIENT_IMPL *);
+} XSASL_CLIENT_IMPL;
+
+extern XSASL_CLIENT_IMPL *xsasl_client_init(const char *, const char *);
+extern ARGV *xsasl_client_types(void);
+
+#define xsasl_client_create(impl, args) \
+	(impl)->create((impl), (args))
+#define XSASL_CLIENT_CREATE(impl, args, a1, a2, a3, a4) \
+	xsasl_client_create((impl), (((args)->a1), ((args)->a2), ((args)->a3), \
+	((args)->a4), (args)))
+#define xsasl_client_done(impl) (impl)->done((impl));
+
+ /*
+  * Status codes.
+  */
+#define XSASL_AUTH_OK	1		/* Success */
+#define XSASL_AUTH_MORE	2		/* Need another c/s protocol exchange */
+#define XSASL_AUTH_DONE	3		/* Authentication completed */
+#define XSASL_AUTH_FORM	4		/* Cannot decode response */
+#define XSASL_AUTH_FAIL	5		/* Error */
+#define XSASL_AUTH_TEMP	6		/* Temporary error condition */
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	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
+/*--*/
+
+#endif
diff --git a/src/xsasl/xsasl_client.c b/src/xsasl/xsasl_client.c
new file mode 100644
index 0000000..0bddd41
--- /dev/null
+++ b/src/xsasl/xsasl_client.c
@@ -0,0 +1,240 @@
+/*++
+/* NAME
+/*	xsasl_client 3
+/* SUMMARY
+/*	Postfix SASL client plug-in interface
+/* SYNOPSIS
+/*	#include <xsasl.h>
+/*
+/*	XSASL_CLIENT_IMPL *xsasl_client_init(client_type, path_info)
+/*	const char *client_type;
+/*	const char *path_info;
+/*
+/*	void	xsasl_client_done(implementation)
+/*	XSASL_CLIENT_IMPL *implementation;
+/*
+/*	ARGV	*xsasl_client_types()
+/*
+/* .in +4
+/*	typedef struct XSASL_CLIENT_CREATE_ARGS {
+/*		VSTREAM	*stream;
+/*		const char *service;
+/*		const char *server_name;
+/*		const char *security_options;
+/*	} XSASL_CLIENT_CREATE_ARGS;
+/* .in -4
+/*
+/*	XSASL_CLIENT *xsasl_client_create(implementation, create_args)
+/*	XSASL_CLIENT_IMPL *implementation;
+/*	XSASL_CLIENT_CREATE_ARGS *create_args;
+/*
+/*	XSASL_CLIENT *XSASL_CLIENT_CREATE(implementation, create_args,
+/*					stream = stream_val,
+/*					...,
+/*					security_options = prop_val)
+/*	XSASL_CLIENT_IMPL *implementation;
+/*	XSASL_CLIENT_CREATE_ARGS *create_args;
+/*
+/*	void	xsasl_client_free(client)
+/*	XSASL_CLIENT *client;
+/*
+/*	int	xsasl_client_first(client, stream, mech_list, username,
+/*					password, auth_method, init_resp)
+/*	XSASL_CLIENT *client;
+/*	const char *mech_list;
+/*	const char *username;
+/*	const char *password;
+/*	const char **auth_method;
+/*	VSTRING *init_resp;
+/*
+/*	int	xsasl_client_next(client, server_reply, client_reply)
+/*	XSASL_CLIENT *client;
+/*	const char *server_reply;
+/*	VSTRING *client_reply;
+/* DESCRIPTION
+/*	The XSASL_CLIENT abstraction implements a generic interface
+/*	to one or more SASL authentication implementations.
+/*
+/*	xsasl_client_init() is called once during process initialization.
+/*	It selects a SASL implementation by name, specifies the
+/*	location of a configuration file or rendez-vous point, and
+/*	returns an implementation handle that can be used to generate
+/*	SASL client instances. This function is typically used to
+/*	initialize the underlying implementation.
+/*
+/*	xsasl_client_done() disposes of an implementation handle,
+/*	and allows the underlying implementation to release resources.
+/*
+/*	xsasl_client_types() lists the available implementation types.
+/*	The result should be destroyed by the caller.
+/*
+/*	xsasl_client_create() is called at the start of an SMTP
+/*	session. It generates a Postfix SASL plug-in client instance
+/*	for the specified service and server name, with the specified
+/*	security properties. The stream handle is stored so that
+/*	encryption can be turned on after successful negotiations.
+/*
+/*	XSASL_CLIENT_CREATE() is a macro that provides an interface
+/*	with named parameters.  Named parameters do not have to
+/*	appear in a fixed order. The parameter names correspond to
+/*	the member names of the XSASL_CLIENT_CREATE_ARGS structure.
+/*
+/*	xsasl_client_free() is called at the end of an SMTP session.
+/*	It destroys a SASL client instance, and disables further
+/*	read/write operations if encryption was turned on.
+/*
+/*	xsasl_client_first() produces the client input for the AUTH
+/*	command. The input is an authentication method list from
+/*	an EHLO response, a username and a password. On return, the
+/*	method argument specifies the authentication method; storage
+/*	space is owned by the underlying implementation.  The initial
+/*	response and client non-error replies are BASE64 encoded.
+/*	Client error replies are 7-bit ASCII text without control
+/*	characters, and without BASE64 encoding. They are meant for
+/*	the local application, not for transmission to the server.
+/*	The client may negotiate encryption of the client-server
+/*	connection.
+/*
+/*	The result is one of the following:
+/* .IP XSASL_AUTH_OK
+/*	Success.
+/* .IP XSASL_AUTH_FORM
+/*	The server reply is incorrectly formatted. The client error
+/*	reply explains why.
+/* .IP XSASL_AUTH_FAIL
+/*	Other error. The client error reply explains why.
+/* .PP
+/*	xsasl_client_next() supports the subsequent stages of the
+/*	AUTH protocol. Both the client reply and client non-error
+/*	responses are BASE64 encoded.  See xsasl_client_first() for
+/*	other details.
+/*
+/*	Arguments:
+/* .IP client
+/*	SASL plug-in client handle.
+/* .IP client_reply
+/*	BASE64 encoded non-error client reply, or ASCII error
+/*	description for the user.
+/* .IP client_type
+/*	The name of a Postfix SASL client plug_in implementation.
+/* .IP client_types
+/*	Null-terminated array of strings with SASL client plug-in
+/*	implementation names.
+/* .IP init_resp
+/*	The AUTH command initial response.
+/* .IP implementation
+/*	Implementation handle that was obtained with xsasl_client_init().
+/* .IP mech_list
+/*	List of SASL mechanisms as announced by the server.
+/* .IP auth_method
+/*	The AUTH command authentication method.
+/* .IP password
+/*	Information from the Postfix SASL password file or equivalent.
+/* .IP path_info
+/*	The value of the smtp_sasl_path parameter or equivalent.
+/*	This specifies the implementation-dependent location of a
+/*	configuration file, rendez-vous point, etc., and is passed
+/*	unchanged to the plug-in.
+/* .IP security_options
+/*	The value of the smtp_sasl_security_options parameter or
+/*	equivalent. This is passed unchanged to the plug-in.
+/* .IP server_name
+/*	The remote server fully qualified hostname.
+/* .IP server_reply
+/*	BASE64 encoded server reply without SMTP reply code or
+/*	enhanced status code.
+/* .IP service
+/*	The service that is implemented by the local client (typically,
+/*	"lmtp" or "smtp").
+/* .IP stream
+/*	The connection between client and server.
+/*	When SASL encryption is negotiated, the plug-in will
+/*	transparently intercept the socket read/write operations.
+/* .IP username
+/*	Information from the Postfix SASL password file.
+/* SECURITY
+/* .ad
+/* .fi
+/*	The caller does not sanitize the server reply. It is the
+/*	responsibility of the underlying SASL client implementation
+/*	to produce 7-bit ASCII without control characters as client
+/*	non-error and error replies.
+/* DIAGNOSTICS
+/*	In case of error, xsasl_client_init() and xsasl_client_create()
+/*	log a warning and return a null pointer.
+/*
+/*	Functions that normally return XSASL_AUTH_OK will log a warning
+/*	and return an appropriate result value.
+/*
+/*	Panic: interface violation.
+/*
+/*	Fatal errors: out of memory.
+/* SEE ALSO
+/*	cyrus_security(3) Cyrus SASL security features
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this
+/*	software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+
+/* SASL implementations. */
+
+#include <xsasl.h>
+#include <xsasl_cyrus.h>
+
+ /*
+  * Lookup table for available SASL client implementations.
+  */
+typedef struct {
+    char   *client_type;
+    struct XSASL_CLIENT_IMPL *(*client_init) (const char *, const char *);
+} XSASL_CLIENT_IMPL_INFO;
+
+static const XSASL_CLIENT_IMPL_INFO client_impl_info[] = {
+#ifdef XSASL_TYPE_CYRUS
+    XSASL_TYPE_CYRUS, xsasl_cyrus_client_init,
+#endif
+    0,
+};
+
+/* xsasl_client_init - look up client implementation by name */
+
+XSASL_CLIENT_IMPL *xsasl_client_init(const char *client_type,
+				             const char *path_info)
+{
+    const XSASL_CLIENT_IMPL_INFO *xp;
+
+    for (xp = client_impl_info; xp->client_type; xp++)
+	if (strcmp(client_type, xp->client_type) == 0)
+	    return (xp->client_init(client_type, path_info));
+    msg_warn("unsupported SASL client implementation: %s", client_type);
+    return (0);
+}
+
+/* xsasl_client_types - report available implementation types */
+
+ARGV   *xsasl_client_types(void)
+{
+    const XSASL_CLIENT_IMPL_INFO *xp;
+    ARGV   *argv = argv_alloc(1);
+
+    for (xp = client_impl_info; xp->client_type; xp++)
+	argv_add(argv, xp->client_type, ARGV_END);
+    return (argv);
+}
diff --git a/src/xsasl/xsasl_cyrus.h b/src/xsasl/xsasl_cyrus.h
new file mode 100644
index 0000000..ad8557e
--- /dev/null
+++ b/src/xsasl/xsasl_cyrus.h
@@ -0,0 +1,47 @@
+#ifndef _XSASL_CYRUS_H_INCLUDED_
+#define _XSASL_CYRUS_H_INCLUDED_
+
+/*++
+/* NAME
+/*	xsasl_cyrus 3h
+/* SUMMARY
+/*	Cyrus SASL plug-in
+/* SYNOPSIS
+/*	#include <xsasl_cyrus.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * XSASL library.
+  */
+#include <xsasl.h>
+
+#if defined(USE_SASL_AUTH) && defined(USE_CYRUS_SASL)
+
+ /*
+  * SASL protocol interface
+  */
+#define XSASL_TYPE_CYRUS "cyrus"
+
+extern XSASL_SERVER_IMPL *xsasl_cyrus_server_init(const char *, const char *);
+extern XSASL_CLIENT_IMPL *xsasl_cyrus_client_init(const char *, const char *);
+
+ /*
+  * Internal definitions for client and server module.
+  */
+typedef int (*XSASL_CYRUS_CB) (void);
+
+#endif
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+#endif
diff --git a/src/xsasl/xsasl_cyrus_client.c b/src/xsasl/xsasl_cyrus_client.c
new file mode 100644
index 0000000..fc799c9
--- /dev/null
+++ b/src/xsasl/xsasl_cyrus_client.c
@@ -0,0 +1,585 @@
+/*++
+/* NAME
+/*	xsasl_cyrus_client 3
+/* SUMMARY
+/*	Cyrus SASL client-side plug-in
+/* SYNOPSIS
+/*	#include <xsasl_cyrus_client.h>
+/*
+/*	XSASL_CLIENT_IMPL *xsasl_cyrus_client_init(client_type, path_info)
+/*	const char *client_type;
+/* DESCRIPTION
+/*	This module implements the Cyrus SASL client-side authentication
+/*	plug-in.
+/*
+/*	xsasl_cyrus_client_init() initializes the Cyrus SASL library and
+/*	returns an implementation handle that can be used to generate
+/*	SASL client instances.
+/*
+/*	Arguments:
+/* .IP client_type
+/*	The plug-in SASL client type (cyrus). This argument is
+/*	ignored, but it could be used when one implementation
+/*	provides multiple variants.
+/* .IP path_info
+/*	Implementation-specific information to specify the location
+/*	of a configuration file, rendez-vous point, etc. This
+/*	information is ignored by the Cyrus SASL client plug-in.
+/* DIAGNOSTICS
+/*	Fatal: out of memory.
+/*
+/*	Panic: interface violation.
+/*
+/*	Other: the routines log a warning and return an error result
+/*	as specified in xsasl_client(3).
+/* SEE ALSO
+/*	xsasl_client(3) Client API
+/* 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>
+
+ /*
+  * Global library
+  */
+#include <mail_params.h>
+
+ /*
+  * Application-specific
+  */
+#include <xsasl.h>
+#include <xsasl_cyrus.h>
+#include <xsasl_cyrus_common.h>
+
+#if defined(USE_SASL_AUTH) && defined(USE_CYRUS_SASL)
+
+#include <sasl.h>
+#include <saslutil.h>
+
+/*
+ * Silly little macros.
+ */
+#define STR(s)  vstring_str(s)
+
+ /*
+  * Macros to handle API differences between SASLv1 and SASLv2. Specifics:
+  * 
+  * The SASL_LOG_* constants were renamed in SASLv2.
+  * 
+  * SASLv2's sasl_client_new takes two new parameters to specify local and
+  * remote IP addresses for auth mechs that use them.
+  * 
+  * SASLv2's sasl_client_start function no longer takes the secret parameter.
+  * 
+  * SASLv2's sasl_decode64 function takes an extra parameter for the length of
+  * the output buffer.
+  * 
+  * The other major change is that SASLv2 now takes more responsibility for
+  * deallocating memory that it allocates internally.  Thus, some of the
+  * function parameters are now 'const', to make sure we don't try to free
+  * them too.  This is dealt with in the code later on.
+  */
+#if SASL_VERSION_MAJOR < 2
+/* SASL version 1.x */
+#define SASL_CLIENT_NEW(srv, fqdn, lport, rport, prompt, secflags, pconn) \
+	sasl_client_new(srv, fqdn, prompt, secflags, pconn)
+#define SASL_CLIENT_START(conn, mechlst, secret, prompt, clout, cllen, mech) \
+	sasl_client_start(conn, mechlst, secret, prompt, clout, cllen, mech)
+#define SASL_DECODE64(in, inlen, out, outmaxlen, outlen) \
+	sasl_decode64(in, inlen, out, outlen)
+typedef char *CLIENTOUT_TYPE;
+
+#endif
+
+#if SASL_VERSION_MAJOR >= 2
+/* SASL version > 2.x */
+#define SASL_CLIENT_NEW(srv, fqdn, lport, rport, prompt, secflags, pconn) \
+	sasl_client_new(srv, fqdn, lport, rport, prompt, secflags, pconn)
+#define SASL_CLIENT_START(conn, mechlst, secret, prompt, clout, cllen, mech) \
+	sasl_client_start(conn, mechlst, prompt, clout, cllen, mech)
+#define SASL_DECODE64(in, inlen, out, outmaxlen, outlen) \
+	sasl_decode64(in, inlen, out, outmaxlen, outlen)
+typedef const char *CLIENTOUT_TYPE;
+
+#endif
+
+ /*
+  * The XSASL_CYRUS_CLIENT object is derived from the generic XSASL_CLIENT
+  * object.
+  */
+typedef struct {
+    XSASL_CLIENT xsasl;			/* generic members, must be first */
+    VSTREAM *stream;			/* client-server connection */
+    sasl_conn_t *sasl_conn;		/* SASL context */
+    VSTRING *decoded;			/* decoded server challenge */
+    sasl_callback_t *callbacks;		/* user/password lookup */
+    char   *username;
+    char   *password;
+} XSASL_CYRUS_CLIENT;
+
+ /*
+  * Forward declarations.
+  */
+static void xsasl_cyrus_client_done(XSASL_CLIENT_IMPL *);
+static XSASL_CLIENT *xsasl_cyrus_client_create(XSASL_CLIENT_IMPL *,
+					        XSASL_CLIENT_CREATE_ARGS *);
+static int xsasl_cyrus_client_set_security(XSASL_CLIENT *, const char *);
+static int xsasl_cyrus_client_first(XSASL_CLIENT *, const char *, const char *,
+			            const char *, const char **, VSTRING *);
+static int xsasl_cyrus_client_next(XSASL_CLIENT *, const char *, VSTRING *);
+static void xsasl_cyrus_client_free(XSASL_CLIENT *);
+
+/* xsasl_cyrus_client_get_user - username lookup call-back routine */
+
+static int xsasl_cyrus_client_get_user(void *context, int unused_id,
+				               const char **result,
+				               unsigned *len)
+{
+    const char *myname = "xsasl_cyrus_client_get_user";
+    XSASL_CYRUS_CLIENT *client = (XSASL_CYRUS_CLIENT *) context;
+
+    if (msg_verbose)
+	msg_info("%s: %s", myname, client->username);
+
+    /*
+     * Sanity check.
+     */
+    if (client->password == 0)
+	msg_panic("%s: no username looked up", myname);
+
+    *result = client->username;
+    if (len)
+	*len = strlen(client->username);
+    return (SASL_OK);
+}
+
+/* xsasl_cyrus_client_get_passwd - password lookup call-back routine */
+
+static int xsasl_cyrus_client_get_passwd(sasl_conn_t *conn, void *context,
+				            int id, sasl_secret_t **psecret)
+{
+    const char *myname = "xsasl_cyrus_client_get_passwd";
+    XSASL_CYRUS_CLIENT *client = (XSASL_CYRUS_CLIENT *) context;
+    int     len;
+
+    if (msg_verbose)
+	msg_info("%s: %s", myname, client->password);
+
+    /*
+     * Sanity check.
+     */
+    if (!conn || !psecret || id != SASL_CB_PASS)
+	return (SASL_BADPARAM);
+    if (client->password == 0)
+	msg_panic("%s: no password looked up", myname);
+
+    /*
+     * Convert the password into a counted string.
+     */
+    len = strlen(client->password);
+    if ((*psecret = (sasl_secret_t *) malloc(sizeof(sasl_secret_t) + len)) == 0)
+	return (SASL_NOMEM);
+    (*psecret)->len = len;
+    memcpy((*psecret)->data, client->password, len + 1);
+
+    return (SASL_OK);
+}
+
+/* xsasl_cyrus_client_init - initialize Cyrus SASL library */
+
+XSASL_CLIENT_IMPL *xsasl_cyrus_client_init(const char *unused_client_type,
+				               const char *unused_path_info)
+{
+    XSASL_CLIENT_IMPL *xp;
+    int     sasl_status;
+
+    /*
+     * Global callbacks. These have no per-session context.
+     */
+    static sasl_callback_t callbacks[] = {
+	{SASL_CB_LOG, (XSASL_CYRUS_CB) &xsasl_cyrus_log, 0},
+	{SASL_CB_LIST_END, 0, 0}
+    };
+
+#if SASL_VERSION_MAJOR >= 2 && (SASL_VERSION_MINOR >= 2 \
+    || (SASL_VERSION_MINOR == 1 && SASL_VERSION_STEP >= 19))
+    int     sasl_major;
+    int     sasl_minor;
+    int     sasl_step;
+
+    /*
+     * DLL hell guard.
+     */
+    sasl_version_info((const char **) 0, (const char **) 0,
+		      &sasl_major, &sasl_minor,
+		      &sasl_step, (int *) 0);
+    if (sasl_major != SASL_VERSION_MAJOR
+#if 0
+	|| sasl_minor != SASL_VERSION_MINOR
+	|| sasl_step != SASL_VERSION_STEP
+#endif
+	) {
+	msg_warn("incorrect SASL library version. "
+	      "Postfix was built with include files from version %d.%d.%d, "
+		 "but the run-time library version is %d.%d.%d",
+		 SASL_VERSION_MAJOR, SASL_VERSION_MINOR, SASL_VERSION_STEP,
+		 sasl_major, sasl_minor, sasl_step);
+	return (0);
+    }
+#endif
+
+    if (*var_cyrus_conf_path) {
+#ifdef SASL_PATH_TYPE_CONFIG			/* Cyrus SASL 2.1.22 */
+	if (sasl_set_path(SASL_PATH_TYPE_CONFIG,
+			  var_cyrus_conf_path) != SASL_OK)
+	    msg_warn("failed to set Cyrus SASL configuration path: \"%s\"",
+		     var_cyrus_conf_path);
+#else
+	msg_warn("%s is not empty, but setting the Cyrus SASL configuration "
+		 "path is not supported with SASL library version %d.%d.%d",
+		 VAR_CYRUS_CONF_PATH, SASL_VERSION_MAJOR,
+		 SASL_VERSION_MINOR, SASL_VERSION_STEP);
+#endif
+    }
+
+    /*
+     * Initialize the SASL library.
+     */
+    if ((sasl_status = sasl_client_init(callbacks)) != SASL_OK) {
+	msg_warn("SASL library initialization error: %s",
+		 xsasl_cyrus_strerror(sasl_status));
+	return (0);
+    }
+
+    /*
+     * Return a generic XSASL_CLIENT_IMPL object. We don't need to extend it
+     * with our own methods or data.
+     */
+    xp = (XSASL_CLIENT_IMPL *) mymalloc(sizeof(*xp));
+    xp->create = xsasl_cyrus_client_create;
+    xp->done = xsasl_cyrus_client_done;
+    return (xp);
+}
+
+/* xsasl_cyrus_client_done - dispose of implementation */
+
+static void xsasl_cyrus_client_done(XSASL_CLIENT_IMPL *impl)
+{
+    myfree((void *) impl);
+    sasl_done();
+}
+
+/* xsasl_cyrus_client_create - per-session SASL initialization */
+
+XSASL_CLIENT *xsasl_cyrus_client_create(XSASL_CLIENT_IMPL *unused_impl,
+				             XSASL_CLIENT_CREATE_ARGS *args)
+{
+    XSASL_CYRUS_CLIENT *client = 0;
+    static sasl_callback_t callbacks[] = {
+	{SASL_CB_USER, (XSASL_CYRUS_CB) &xsasl_cyrus_client_get_user, 0},
+	{SASL_CB_AUTHNAME, (XSASL_CYRUS_CB) &xsasl_cyrus_client_get_user, 0},
+	{SASL_CB_PASS, (XSASL_CYRUS_CB) &xsasl_cyrus_client_get_passwd, 0},
+	{SASL_CB_LIST_END, 0, 0}
+    };
+    sasl_conn_t *sasl_conn = 0;
+    sasl_callback_t *custom_callbacks = 0;
+    sasl_callback_t *cp;
+    int     sasl_status;
+
+    /*
+     * The optimizer will eliminate code duplication and/or dead code.
+     */
+#define XSASL_CYRUS_CLIENT_CREATE_ERROR_RETURN(x) \
+    do { \
+	if (client) { \
+	    xsasl_cyrus_client_free(&client->xsasl); \
+	} else { \
+	    if (custom_callbacks) \
+		myfree((void *) custom_callbacks); \
+	    if (sasl_conn) \
+		sasl_dispose(&sasl_conn); \
+	} \
+	return (x); \
+    } while (0)
+
+    /*
+     * Per-session initialization. Provide each session with its own callback
+     * context.
+     */
+#define NULL_SECFLAGS		0
+
+    custom_callbacks = (sasl_callback_t *) mymalloc(sizeof(callbacks));
+    memcpy((void *) custom_callbacks, callbacks, sizeof(callbacks));
+
+#define NULL_SERVER_ADDR	((char *) 0)
+#define NULL_CLIENT_ADDR	((char *) 0)
+
+    if ((sasl_status = SASL_CLIENT_NEW(args->service, args->server_name,
+				       NULL_CLIENT_ADDR, NULL_SERVER_ADDR,
+				 var_cyrus_sasl_authzid ? custom_callbacks :
+				       custom_callbacks + 1, NULL_SECFLAGS,
+				       &sasl_conn)) != SASL_OK) {
+	msg_warn("per-session SASL client initialization: %s",
+		 xsasl_cyrus_strerror(sasl_status));
+	XSASL_CYRUS_CLIENT_CREATE_ERROR_RETURN(0);
+    }
+
+    /*
+     * Extend the XSASL_CLIENT object with our own state. We use long-lived
+     * conversion buffers rather than local variables to avoid memory leaks
+     * in case of read/write timeout or I/O error.
+     * 
+     * XXX If we enable SASL encryption, there needs to be a way to inform the
+     * application, so that they can turn off connection caching, refuse
+     * STARTTLS, etc.
+     */
+    client = (XSASL_CYRUS_CLIENT *) mymalloc(sizeof(*client));
+    client->xsasl.free = xsasl_cyrus_client_free;
+    client->xsasl.first = xsasl_cyrus_client_first;
+    client->xsasl.next = xsasl_cyrus_client_next;
+    client->stream = args->stream;
+    client->sasl_conn = sasl_conn;
+    client->callbacks = custom_callbacks;
+    client->decoded = vstring_alloc(20);
+    client->username = 0;
+    client->password = 0;
+
+    for (cp = custom_callbacks; cp->id != SASL_CB_LIST_END; cp++)
+	cp->context = (void *) client;
+
+    if (xsasl_cyrus_client_set_security(&client->xsasl,
+					args->security_options)
+	!= XSASL_AUTH_OK)
+	XSASL_CYRUS_CLIENT_CREATE_ERROR_RETURN(0);
+
+    return (&client->xsasl);
+}
+
+/* xsasl_cyrus_client_set_security - set security properties */
+
+static int xsasl_cyrus_client_set_security(XSASL_CLIENT *xp,
+					           const char *sasl_opts_val)
+{
+    XSASL_CYRUS_CLIENT *client = (XSASL_CYRUS_CLIENT *) xp;
+    sasl_security_properties_t sec_props;
+    int     sasl_status;
+
+    /*
+     * Per-session security properties. XXX This routine is not sufficiently
+     * documented. What is the purpose of all this?
+     */
+    memset(&sec_props, 0, sizeof(sec_props));
+    sec_props.min_ssf = 0;
+    sec_props.max_ssf = 0;			/* don't allow real SASL
+						 * security layer */
+    if (*sasl_opts_val == 0) {
+	sec_props.security_flags = 0;
+    } else {
+	sec_props.security_flags =
+	    xsasl_cyrus_security_parse_opts(sasl_opts_val);
+	if (sec_props.security_flags == 0) {
+	    msg_warn("bad per-session SASL security properties");
+	    return (XSASL_AUTH_FAIL);
+	}
+    }
+    sec_props.maxbufsize = 0;
+    sec_props.property_names = 0;
+    sec_props.property_values = 0;
+    if ((sasl_status = sasl_setprop(client->sasl_conn, SASL_SEC_PROPS,
+				    &sec_props)) != SASL_OK) {
+	msg_warn("set per-session SASL security properties: %s",
+		 xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_FAIL);
+    }
+    return (XSASL_AUTH_OK);
+}
+
+/* xsasl_cyrus_client_first - run authentication protocol */
+
+static int xsasl_cyrus_client_first(XSASL_CLIENT *xp,
+				            const char *mechanism_list,
+				            const char *username,
+				            const char *password,
+				            const char **mechanism,
+				            VSTRING *init_resp)
+{
+    const char *myname = "xsasl_cyrus_client_first";
+    XSASL_CYRUS_CLIENT *client = (XSASL_CYRUS_CLIENT *) xp;
+    unsigned enc_length;
+    unsigned enc_length_out;
+    CLIENTOUT_TYPE clientout;
+    unsigned clientoutlen;
+    int     sasl_status;
+
+#define NO_SASL_SECRET		0
+#define NO_SASL_INTERACTION	0
+
+    /*
+     * Save the username and password for the call-backs.
+     */
+    if (client->username)
+	myfree(client->username);
+    client->username = mystrdup(username);
+    if (client->password)
+	myfree(client->password);
+    client->password = mystrdup(password);
+
+    /*
+     * Start the client side authentication protocol.
+     */
+    sasl_status = SASL_CLIENT_START((sasl_conn_t *) client->sasl_conn,
+				    mechanism_list,
+				    NO_SASL_SECRET, NO_SASL_INTERACTION,
+				    &clientout, &clientoutlen, mechanism);
+    if (sasl_status != SASL_OK && sasl_status != SASL_CONTINUE) {
+	vstring_strcpy(init_resp, xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_FAIL);
+    }
+
+    /*
+     * Generate the AUTH command and the optional initial client response.
+     * sasl_encode64() produces four bytes for each complete or incomplete
+     * triple of input bytes. Allocate an extra byte for string termination.
+     */
+#define ENCODE64_LENGTH(n)	((((n) + 2) / 3) * 4)
+
+    if (clientoutlen > 0) {
+	if (msg_verbose) {
+	    escape(client->decoded, clientout, clientoutlen);
+	    msg_info("%s: uncoded initial reply: %s",
+		     myname, STR(client->decoded));
+	}
+	enc_length = ENCODE64_LENGTH(clientoutlen) + 1;
+	VSTRING_RESET(init_resp);		/* Fix 200512 */
+	VSTRING_SPACE(init_resp, enc_length);
+	if ((sasl_status = sasl_encode64(clientout, clientoutlen,
+					 STR(init_resp),
+					 vstring_avail(init_resp),
+					 &enc_length_out)) != SASL_OK)
+	    msg_panic("%s: sasl_encode64 botch: %s",
+		      myname, xsasl_cyrus_strerror(sasl_status));
+	vstring_set_payload_size(init_resp, enc_length_out);
+#if SASL_VERSION_MAJOR < 2
+	/* SASL version 1 doesn't free memory that it allocates. */
+	free(clientout);
+#endif
+    } else {
+	vstring_strcpy(init_resp, "");
+    }
+    return (XSASL_AUTH_OK);
+}
+
+/* xsasl_cyrus_client_next - continue authentication */
+
+static int xsasl_cyrus_client_next(XSASL_CLIENT *xp, const char *server_reply,
+				           VSTRING *client_reply)
+{
+    const char *myname = "xsasl_cyrus_client_next";
+    XSASL_CYRUS_CLIENT *client = (XSASL_CYRUS_CLIENT *) xp;
+    unsigned enc_length;
+    unsigned enc_length_out;
+    CLIENTOUT_TYPE clientout;
+    unsigned clientoutlen;
+    unsigned serverinlen;
+    int     sasl_status;
+
+    /*
+     * Process a server challenge.
+     */
+    serverinlen = strlen(server_reply);
+    VSTRING_RESET(client->decoded);		/* Fix 200512 */
+    VSTRING_SPACE(client->decoded, serverinlen);
+    if ((sasl_status = SASL_DECODE64(server_reply, serverinlen,
+				     STR(client->decoded),
+				     vstring_avail(client->decoded),
+				     &enc_length)) != SASL_OK) {
+	vstring_strcpy(client_reply, xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_FORM);
+    }
+    if (msg_verbose)
+	msg_info("%s: decoded challenge: %.*s",
+		 myname, (int) enc_length, STR(client->decoded));
+    sasl_status = sasl_client_step(client->sasl_conn, STR(client->decoded),
+				   enc_length, NO_SASL_INTERACTION,
+				   &clientout, &clientoutlen);
+    if (sasl_status != SASL_OK && sasl_status != SASL_CONTINUE) {
+	vstring_strcpy(client_reply, xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_FAIL);
+    }
+
+    /*
+     * Send a client response.
+     */
+    if (clientoutlen > 0) {
+	if (msg_verbose)
+	    msg_info("%s: uncoded client response %.*s",
+		     myname, (int) clientoutlen, clientout);
+	enc_length = ENCODE64_LENGTH(clientoutlen) + 1;
+	VSTRING_RESET(client_reply);		/* Fix 200512 */
+	VSTRING_SPACE(client_reply, enc_length);
+	if ((sasl_status = sasl_encode64(clientout, clientoutlen,
+					 STR(client_reply),
+					 vstring_avail(client_reply),
+					 &enc_length_out)) != SASL_OK)
+	    msg_panic("%s: sasl_encode64 botch: %s",
+		      myname, xsasl_cyrus_strerror(sasl_status));
+#if SASL_VERSION_MAJOR < 2
+	/* SASL version 1 doesn't free memory that it allocates. */
+	free(clientout);
+#endif
+    } else {
+	/* XXX Can't happen. */
+	vstring_strcpy(client_reply, "");
+    }
+    return (XSASL_AUTH_OK);
+}
+
+/* xsasl_cyrus_client_free - per-session cleanup */
+
+void    xsasl_cyrus_client_free(XSASL_CLIENT *xp)
+{
+    XSASL_CYRUS_CLIENT *client = (XSASL_CYRUS_CLIENT *) xp;
+
+    if (client->username)
+	myfree(client->username);
+    if (client->password)
+	myfree(client->password);
+    if (client->sasl_conn)
+	sasl_dispose(&client->sasl_conn);
+    myfree((void *) client->callbacks);
+    vstring_free(client->decoded);
+    myfree((void *) client);
+}
+
+#endif
diff --git a/src/xsasl/xsasl_cyrus_common.h b/src/xsasl/xsasl_cyrus_common.h
new file mode 100644
index 0000000..5447378
--- /dev/null
+++ b/src/xsasl/xsasl_cyrus_common.h
@@ -0,0 +1,39 @@
+#ifndef _CYRUS_COMMON_H_INCLUDED_
+#define _CYRUS_COMMON_H_INCLUDED_
+
+/*++
+/* NAME
+/*	cyrus_common 3h
+/* SUMMARY
+/*	Cyrus SASL plug-in helpers
+/* SYNOPSIS
+/*	#include <cyrus_common.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * External interface.
+  */
+#if defined(USE_SASL_AUTH) && defined(USE_CYRUS_SASL)
+
+#define NO_SASL_LANGLIST	((const char *) 0)
+#define NO_SASL_OUTLANG		((const char **) 0)
+#define xsasl_cyrus_strerror(status) \
+	sasl_errstring((status), NO_SASL_LANGLIST, NO_SASL_OUTLANG)
+extern int xsasl_cyrus_log(void *, int, const char *);
+extern int xsasl_cyrus_security_parse_opts(const char *);
+
+#endif
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+#endif
diff --git a/src/xsasl/xsasl_cyrus_log.c b/src/xsasl/xsasl_cyrus_log.c
new file mode 100644
index 0000000..7bf25c3
--- /dev/null
+++ b/src/xsasl/xsasl_cyrus_log.c
@@ -0,0 +1,104 @@
+/*++
+/* NAME
+/*	xsasl_cyrus_log 3
+/* SUMMARY
+/*	Cyrus SASL logging call-back routine
+/* SYNOPSIS
+/*	#include <xsasl_cyrus_common.h>
+/*
+/*	int	xsasl_cyrus_log(context, priority, text)
+/*	void	*context;
+/*	int	priority;
+/*	const char *text;
+/* DESCRIPTION
+/*	xsasl_cyrus_log() logs a Cyrus message.
+/* DIAGNOSTICS:
+/*	Fatal: out of memory.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+
+/* Utility library. */
+
+#include <msg.h>
+
+/* Application-specific */
+
+#include <xsasl_cyrus_common.h>
+
+#if defined(USE_SASL_AUTH) && defined(USE_CYRUS_SASL)
+
+#include <sasl.h>
+#include <saslutil.h>
+
+/* xsasl_cyrus_log - logging callback */
+
+int     xsasl_cyrus_log(void *unused_context, int priority,
+			        const char *message)
+{
+    switch (priority) {
+	case SASL_LOG_ERR:		/* unusual errors */
+#ifdef SASL_LOG_WARN			/* non-fatal warnings (Cyrus-SASL v2) */
+	case SASL_LOG_WARN:
+#endif
+#ifdef SASL_LOG_WARNING			/* non-fatal warnings (Cyrus-SASL v1) */
+	case SASL_LOG_WARNING:
+#endif
+	msg_warn("SASL authentication problem: %s", message);
+	break;
+#ifdef SASL_LOG_INFO
+    case SASL_LOG_INFO:			/* other info (Cyrus-SASL v1) */
+	if (msg_verbose)
+	    msg_info("SASL authentication info: %s", message);
+	break;
+#endif
+#ifdef SASL_LOG_NOTE
+    case SASL_LOG_NOTE:			/* other info (Cyrus-SASL v2) */
+	if (msg_verbose)
+	    msg_info("SASL authentication info: %s", message);
+	break;
+#endif
+#ifdef SASL_LOG_FAIL
+    case SASL_LOG_FAIL:			/* authentication failures
+						 * (Cyrus-SASL v2) */
+	msg_warn("SASL authentication failure: %s", message);
+	break;
+#endif
+#ifdef SASL_LOG_DEBUG
+    case SASL_LOG_DEBUG:			/* more verbose than LOG_NOTE
+						 * (Cyrus-SASL v2) */
+	if (msg_verbose > 1)
+	    msg_info("SASL authentication debug: %s", message);
+	break;
+#endif
+#ifdef SASL_LOG_TRACE
+    case SASL_LOG_TRACE:			/* traces of internal
+						 * protocols (Cyrus-SASL v2) */
+	if (msg_verbose > 1)
+	    msg_info("SASL authentication trace: %s", message);
+	break;
+#endif
+#ifdef SASL_LOG_PASS
+    case SASL_LOG_PASS:			/* traces of internal
+						 * protocols, including
+						 * passwords (Cyrus-SASL v2) */
+	if (msg_verbose > 1)
+	    msg_info("SASL authentication pass: %s", message);
+	break;
+#endif
+    }
+    return (SASL_OK);
+}
+
+#endif
diff --git a/src/xsasl/xsasl_cyrus_security.c b/src/xsasl/xsasl_cyrus_security.c
new file mode 100644
index 0000000..7ca7216
--- /dev/null
+++ b/src/xsasl/xsasl_cyrus_security.c
@@ -0,0 +1,87 @@
+/*++
+/* NAME
+/*	xsasl_cyrus_security 3
+/* SUMMARY
+/*	convert Cyrus SASL security properties to bit mask
+/* SYNOPSIS
+/*	#include <xsasl_cyrus_common.h>
+/*
+/*	int	xsasl_cyrus_security_parse_opts(properties)
+/*	const char *properties;
+/* DESCRIPTION
+/*	xsasl_cyrus_security_parse_opts() converts a list of security
+/*	properties to a bit mask. The result is zero in case of error.
+/*
+/*	Arguments:
+/* .IP properties
+/*	A comma or space separated list of zero or more of the
+/*	following:
+/* .RS
+/* .IP noplaintext
+/*	Disallow authentication methods that use plaintext passwords.
+/* .IP noactive
+/*	Disallow authentication methods that are vulnerable to
+/*	non-dictionary active attacks.
+/* .IP nodictionary
+/*	Disallow authentication methods that are vulnerable to
+/*	passive dictionary attack.
+/* .IP forward_secrecy
+/*	Require forward secrecy between sessions.
+/* .IP noanonymous
+/*	Disallow anonymous logins.
+/* .RE
+/* DIAGNOSTICS:
+/*	Warning: bad input.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+
+/* Utility library. */
+
+#include <name_mask.h>
+
+/* Application-specific. */
+
+#include <xsasl_cyrus_common.h>
+
+#if defined(USE_SASL_AUTH) && defined(USE_CYRUS_SASL)
+
+#include <sasl.h>
+
+ /*
+  * SASL Security options.
+  */
+static const NAME_MASK xsasl_cyrus_sec_mask[] = {
+    "noplaintext", SASL_SEC_NOPLAINTEXT,
+    "noactive", SASL_SEC_NOACTIVE,
+    "nodictionary", SASL_SEC_NODICTIONARY,
+#ifdef SASL_SEC_FORWARD_SECRECY
+    "forward_secrecy", SASL_SEC_FORWARD_SECRECY,
+#endif
+    "noanonymous", SASL_SEC_NOANONYMOUS,
+#if SASL_VERSION_MAJOR >= 2
+    "mutual_auth", SASL_SEC_MUTUAL_AUTH,
+#endif
+    0,
+};
+
+/* xsasl_cyrus_security - parse security options */
+
+int     xsasl_cyrus_security_parse_opts(const char *sasl_opts_val)
+{
+    return (name_mask_opt("SASL security options", xsasl_cyrus_sec_mask,
+			  sasl_opts_val, NAME_MASK_RETURN));
+}
+
+#endif
diff --git a/src/xsasl/xsasl_cyrus_server.c b/src/xsasl/xsasl_cyrus_server.c
new file mode 100644
index 0000000..89e1fc9
--- /dev/null
+++ b/src/xsasl/xsasl_cyrus_server.c
@@ -0,0 +1,641 @@
+/*++
+/* NAME
+/*	xsasl_cyrus_server 3
+/* SUMMARY
+/*	Cyrus SASL server-side plug-in
+/* SYNOPSIS
+/*	#include <xsasl_cyrus_server.h>
+/*
+/*	XSASL_SERVER_IMPL *xsasl_cyrus_server_init(server_type, path_info)
+/*	const char *server_type;
+/*	const char *path_info;
+/* DESCRIPTION
+/*	This module implements the Cyrus SASL server-side authentication
+/*	plug-in.
+/*
+/*	xsasl_cyrus_server_init() initializes the Cyrus SASL library and
+/*	returns an implementation handle that can be used to generate
+/*	SASL server instances.
+/*
+/*	Arguments:
+/* .IP server_type
+/*	The server type (cyrus). This argument is ignored, but it
+/*	could be used when one implementation provides multiple
+/*	variants.
+/* .IP path_info
+/*	The base name of the SASL server configuration file (example:
+/*	smtpd becomes /usr/lib/sasl2/smtpd.conf).
+/* DIAGNOSTICS
+/*	Fatal: out of memory.
+/*
+/*	Panic: interface violation.
+/*
+/*	Other: the routines log a warning and return an error result
+/*	as specified in xsasl_server(3).
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Initial implementation by:
+/*	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 <sys/socket.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <name_mask.h>
+#include <stringops.h>
+
+/* Global library. */
+
+#include <mail_params.h>
+
+/* Application-specific. */
+
+#include <xsasl.h>
+#include <xsasl_cyrus.h>
+#include <xsasl_cyrus_common.h>
+
+#if defined(USE_SASL_AUTH) && defined(USE_CYRUS_SASL)
+
+#include <sasl.h>
+#include <saslutil.h>
+
+/*
+ * Silly little macros.
+ */
+#define STR(s)	vstring_str(s)
+
+ /*
+  * Macros to handle API differences between SASLv1 and SASLv2. Specifics:
+  * 
+  * The SASL_LOG_* constants were renamed in SASLv2.
+  * 
+  * SASLv2's sasl_server_new takes two new parameters to specify local and
+  * remote IP addresses for auth mechs that use them.
+  * 
+  * SASLv2's sasl_server_start and sasl_server_step no longer have the errstr
+  * parameter.
+  * 
+  * SASLv2's sasl_decode64 function takes an extra parameter for the length of
+  * the output buffer.
+  * 
+  * The other major change is that SASLv2 now takes more responsibility for
+  * deallocating memory that it allocates internally.  Thus, some of the
+  * function parameters are now 'const', to make sure we don't try to free
+  * them too.  This is dealt with in the code later on.
+  */
+
+#if SASL_VERSION_MAJOR < 2
+/* SASL version 1.x */
+#define SASL_SERVER_NEW(srv, fqdn, rlm, lport, rport, cb, secflags, pconn) \
+	sasl_server_new(srv, fqdn, rlm, cb, secflags, pconn)
+#define SASL_SERVER_START(conn, mech, clin, clinlen, srvout, srvoutlen, err) \
+	sasl_server_start(conn, mech, clin, clinlen, srvout, srvoutlen, err)
+#define SASL_SERVER_STEP(conn, clin, clinlen, srvout, srvoutlen, err) \
+	sasl_server_step(conn, clin, clinlen, srvout, srvoutlen, err)
+#define SASL_DECODE64(in, inlen, out, outmaxlen, outlen) \
+	sasl_decode64(in, inlen, out, outlen)
+typedef char *MECHANISM_TYPE;
+typedef unsigned MECHANISM_COUNT_TYPE;
+typedef char *SERVEROUT_TYPE;
+typedef void *VOID_SERVEROUT_TYPE;
+
+#endif
+
+#if SASL_VERSION_MAJOR >= 2
+/* SASL version > 2.x */
+#define SASL_SERVER_NEW(srv, fqdn, rlm, lport, rport, cb, secflags, pconn) \
+	sasl_server_new(srv, fqdn, rlm, lport, rport, cb, secflags, pconn)
+#define SASL_SERVER_START(conn, mech, clin, clinlen, srvout, srvoutlen, err) \
+	sasl_server_start(conn, mech, clin, clinlen, srvout, srvoutlen)
+#define SASL_SERVER_STEP(conn, clin, clinlen, srvout, srvoutlen, err) \
+	sasl_server_step(conn, clin, clinlen, srvout, srvoutlen)
+#define SASL_DECODE64(in, inlen, out, outmaxlen, outlen) \
+	sasl_decode64(in, inlen, out, outmaxlen, outlen)
+typedef const char *MECHANISM_TYPE;
+typedef int MECHANISM_COUNT_TYPE;
+typedef const char *SERVEROUT_TYPE;
+typedef const void *VOID_SERVEROUT_TYPE;
+
+#endif
+
+#ifndef NO_IP_CYRUS_SASL_AUTH
+#define USE_IP_CYRUS_SASL_AUTH
+#endif
+
+ /*
+  * The XSASL_CYRUS_SERVER object is derived from the generic XSASL_SERVER
+  * object.
+  */
+typedef struct {
+    XSASL_SERVER xsasl;			/* generic members, must be first */
+    VSTREAM *stream;			/* client-server connection */
+    sasl_conn_t *sasl_conn;		/* SASL context */
+    VSTRING *decoded;			/* decoded challenge or response */
+    char   *username;			/* authenticated user */
+    char   *mechanism_list;		/* applicable mechanisms */
+} XSASL_CYRUS_SERVER;
+
+ /*
+  * Forward declarations.
+  */
+static void xsasl_cyrus_server_done(XSASL_SERVER_IMPL *);
+static XSASL_SERVER *xsasl_cyrus_server_create(XSASL_SERVER_IMPL *,
+					        XSASL_SERVER_CREATE_ARGS *);
+static void xsasl_cyrus_server_free(XSASL_SERVER *);
+static int xsasl_cyrus_server_first(XSASL_SERVER *, const char *,
+				            const char *, VSTRING *);
+static int xsasl_cyrus_server_next(XSASL_SERVER *, const char *, VSTRING *);
+static int xsasl_cyrus_server_set_security(XSASL_SERVER *, const char *);
+static const char *xsasl_cyrus_server_get_mechanism_list(XSASL_SERVER *);
+static const char *xsasl_cyrus_server_get_username(XSASL_SERVER *);
+
+ /*
+  * SASL callback interface structure. These call-backs have no per-session
+  * context.
+  */
+#define NO_CALLBACK_CONTEXT	0
+
+static sasl_callback_t callbacks[] = {
+    {SASL_CB_LOG, (XSASL_CYRUS_CB) &xsasl_cyrus_log, NO_CALLBACK_CONTEXT},
+    {SASL_CB_LIST_END, 0, 0}
+};
+
+/* xsasl_cyrus_server_init - create implementation handle */
+
+XSASL_SERVER_IMPL *xsasl_cyrus_server_init(const char *unused_server_type,
+					           const char *path_info)
+{
+    const char *myname = "xsasl_cyrus_server_init";
+    XSASL_SERVER_IMPL *xp;
+    int     sasl_status;
+
+#if SASL_VERSION_MAJOR >= 2 && (SASL_VERSION_MINOR >= 2 \
+    || (SASL_VERSION_MINOR == 1 && SASL_VERSION_STEP >= 19))
+    int     sasl_major;
+    int     sasl_minor;
+    int     sasl_step;
+
+    /*
+     * DLL hell guard.
+     */
+    sasl_version_info((const char **) 0, (const char **) 0,
+		      &sasl_major, &sasl_minor,
+		      &sasl_step, (int *) 0);
+    if (sasl_major != SASL_VERSION_MAJOR
+#if 0
+	|| sasl_minor != SASL_VERSION_MINOR
+	|| sasl_step != SASL_VERSION_STEP
+#endif
+	) {
+	msg_warn("incorrect SASL library version. "
+	      "Postfix was built with include files from version %d.%d.%d, "
+		 "but the run-time library version is %d.%d.%d",
+		 SASL_VERSION_MAJOR, SASL_VERSION_MINOR, SASL_VERSION_STEP,
+		 sasl_major, sasl_minor, sasl_step);
+	return (0);
+    }
+#endif
+
+    if (*var_cyrus_conf_path) {
+#ifdef SASL_PATH_TYPE_CONFIG			/* Cyrus SASL 2.1.22 */
+	if (sasl_set_path(SASL_PATH_TYPE_CONFIG,
+			  var_cyrus_conf_path) != SASL_OK)
+	    msg_warn("failed to set Cyrus SASL configuration path: \"%s\"",
+		     var_cyrus_conf_path);
+#else
+	msg_warn("%s is not empty, but setting the Cyrus SASL configuration "
+		 "path is not supported with SASL library version %d.%d.%d",
+		 VAR_CYRUS_CONF_PATH, SASL_VERSION_MAJOR,
+		 SASL_VERSION_MINOR, SASL_VERSION_STEP);
+#endif
+    }
+
+    /*
+     * Initialize the library: load SASL plug-in routines, etc.
+     */
+    if (msg_verbose)
+	msg_info("%s: SASL config file is %s.conf", myname, path_info);
+    if ((sasl_status = sasl_server_init(callbacks, path_info)) != SASL_OK) {
+	msg_warn("SASL per-process initialization failed: %s",
+		 xsasl_cyrus_strerror(sasl_status));
+	return (0);
+    }
+
+    /*
+     * Return a generic XSASL_SERVER_IMPL object. We don't need to extend it
+     * with our own methods or data.
+     */
+    xp = (XSASL_SERVER_IMPL *) mymalloc(sizeof(*xp));
+    xp->create = xsasl_cyrus_server_create;
+    xp->done = xsasl_cyrus_server_done;
+    return (xp);
+}
+
+/* xsasl_cyrus_server_done - dispose of implementation */
+
+static void xsasl_cyrus_server_done(XSASL_SERVER_IMPL *impl)
+{
+    myfree((void *) impl);
+    sasl_done();
+}
+
+/* xsasl_cyrus_server_create - create server instance */
+
+static XSASL_SERVER *xsasl_cyrus_server_create(XSASL_SERVER_IMPL *unused_impl,
+				             XSASL_SERVER_CREATE_ARGS *args)
+{
+    const char *myname = "xsasl_cyrus_server_create";
+    char   *server_addr_port = 0;
+    char   *client_addr_port = 0;
+    sasl_conn_t *sasl_conn = 0;
+    XSASL_CYRUS_SERVER *server = 0;
+    int     sasl_status;
+
+    if (msg_verbose)
+	msg_info("%s: SASL service=%s, realm=%s",
+		 myname, args->service, args->user_realm ?
+		 args->user_realm : "(null)");
+
+    /*
+     * The optimizer will eliminate code duplication and/or dead code.
+     */
+#define XSASL_CYRUS_SERVER_CREATE_ERROR_RETURN(x) \
+    do { \
+	if (server) { \
+	    xsasl_cyrus_server_free(&server->xsasl); \
+	} else { \
+	    if (sasl_conn) \
+		sasl_dispose(&sasl_conn); \
+	} \
+	XSASL_CYRUS_SERVER_CREATE_RETURN(x); \
+    } while (0)
+
+#define XSASL_CYRUS_SERVER_CREATE_RETURN(x) \
+    do { \
+	if (server_addr_port) \
+	    myfree(server_addr_port); \
+	if (client_addr_port) \
+	    myfree(client_addr_port); \
+	return (x); \
+    } while (0)
+
+    /*
+     * Set up a new server context.
+     */
+#define NO_SECURITY_LAYERS	(0)
+#define NO_SESSION_CALLBACKS	((sasl_callback_t *) 0)
+#define NO_AUTH_REALM		((char *) 0)
+
+#if SASL_VERSION_MAJOR >= 2 && defined(USE_IP_CYRUS_SASL_AUTH)
+
+    /*
+     * Get IP address and port of local and remote endpoints for SASL. Some
+     * implementation supports "[ipv6addr]:port" and "ipv4addr:port" (e.g.,
+     * https://illumos.org/man/3sasl/sasl_server_new), They still support the
+     * historical "address;port" syntax, so we stick with that for now.
+     */
+    server_addr_port = (*args->server_addr && *args->server_port ?
+			concatenate(args->server_addr, ";",
+				    args->server_port, (char *) 0) : 0);
+    client_addr_port = (*args->client_addr && *args->client_port ?
+			concatenate(args->client_addr, ";",
+				    args->client_port, (char *) 0) : 0);
+#else
+
+    /*
+     * Don't give any IP address information to SASL.
+     */
+#endif
+
+    if ((sasl_status =
+	 SASL_SERVER_NEW(args->service, var_myhostname,
+			 args->user_realm ? args->user_realm : NO_AUTH_REALM,
+			 server_addr_port, client_addr_port,
+			 NO_SESSION_CALLBACKS, NO_SECURITY_LAYERS,
+			 &sasl_conn)) != SASL_OK) {
+	msg_warn("SASL per-connection server initialization: %s",
+		 xsasl_cyrus_strerror(sasl_status));
+	XSASL_CYRUS_SERVER_CREATE_ERROR_RETURN(0);
+    }
+
+    /*
+     * Extend the XSASL_SERVER object with our own data. We use long-lived
+     * conversion buffers rather than local variables to avoid memory leaks
+     * in case of read/write timeout or I/O error.
+     */
+    server = (XSASL_CYRUS_SERVER *) mymalloc(sizeof(*server));
+    server->xsasl.free = xsasl_cyrus_server_free;
+    server->xsasl.first = xsasl_cyrus_server_first;
+    server->xsasl.next = xsasl_cyrus_server_next;
+    server->xsasl.get_mechanism_list = xsasl_cyrus_server_get_mechanism_list;
+    server->xsasl.get_username = xsasl_cyrus_server_get_username;
+    server->stream = args->stream;
+    server->sasl_conn = sasl_conn;
+    server->decoded = vstring_alloc(20);
+    server->username = 0;
+    server->mechanism_list = 0;
+
+    if (xsasl_cyrus_server_set_security(&server->xsasl, args->security_options)
+	!= XSASL_AUTH_OK)
+	XSASL_CYRUS_SERVER_CREATE_ERROR_RETURN(0);
+
+    XSASL_CYRUS_SERVER_CREATE_RETURN(&server->xsasl);
+}
+
+/* xsasl_cyrus_server_set_security - set security properties */
+
+static int xsasl_cyrus_server_set_security(XSASL_SERVER *xp,
+					           const char *sasl_opts_val)
+{
+    XSASL_CYRUS_SERVER *server = (XSASL_CYRUS_SERVER *) xp;
+    sasl_security_properties_t sec_props;
+    int     sasl_status;
+
+    /*
+     * Security options. Some information can be found in the sasl.h include
+     * file.
+     */
+    memset(&sec_props, 0, sizeof(sec_props));
+    sec_props.min_ssf = 0;
+    sec_props.max_ssf = 0;			/* don't allow real SASL
+						 * security layer */
+    if (*sasl_opts_val == 0) {
+	sec_props.security_flags = 0;
+    } else {
+	sec_props.security_flags =
+	    xsasl_cyrus_security_parse_opts(sasl_opts_val);
+	if (sec_props.security_flags == 0) {
+	    msg_warn("bad per-session SASL security properties");
+	    return (XSASL_AUTH_FAIL);
+	}
+    }
+    sec_props.maxbufsize = 0;
+    sec_props.property_names = 0;
+    sec_props.property_values = 0;
+
+    if ((sasl_status = sasl_setprop(server->sasl_conn, SASL_SEC_PROPS,
+				    &sec_props)) != SASL_OK) {
+	msg_warn("SASL per-connection security setup; %s",
+		 xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_FAIL);
+    }
+    return (XSASL_AUTH_OK);
+}
+
+/* xsasl_cyrus_server_get_mechanism_list - get available mechanisms */
+
+static const char *xsasl_cyrus_server_get_mechanism_list(XSASL_SERVER *xp)
+{
+    const char *myname = "xsasl_cyrus_server_get_mechanism_list";
+    XSASL_CYRUS_SERVER *server = (XSASL_CYRUS_SERVER *) xp;
+    MECHANISM_TYPE mechanism_list;
+    MECHANISM_COUNT_TYPE mechanism_count;
+    int     sasl_status;
+
+    /*
+     * Get the list of authentication mechanisms.
+     */
+#define UNSUPPORTED_USER	((char *) 0)
+#define IGNORE_MECHANISM_LEN	((unsigned *) 0)
+
+    if ((sasl_status = sasl_listmech(server->sasl_conn, UNSUPPORTED_USER,
+				     "", " ", "",
+				     &mechanism_list,
+				     IGNORE_MECHANISM_LEN,
+				     &mechanism_count)) != SASL_OK) {
+	msg_warn("%s: %s", myname, xsasl_cyrus_strerror(sasl_status));
+	return (0);
+    }
+    if (mechanism_count <= 0) {
+	msg_warn("%s: no applicable SASL mechanisms", myname);
+	return (0);
+    }
+    server->mechanism_list = mystrdup(mechanism_list);
+#if SASL_VERSION_MAJOR < 2
+    /* SASL version 1 doesn't free memory that it allocates. */
+    free(mechanism_list);
+#endif
+    return (server->mechanism_list);
+}
+
+/* xsasl_cyrus_server_free - destroy server instance */
+
+static void xsasl_cyrus_server_free(XSASL_SERVER *xp)
+{
+    XSASL_CYRUS_SERVER *server = (XSASL_CYRUS_SERVER *) xp;
+
+    sasl_dispose(&server->sasl_conn);
+    vstring_free(server->decoded);
+    if (server->username)
+	myfree(server->username);
+    if (server->mechanism_list)
+	myfree(server->mechanism_list);
+    myfree((void *) server);
+}
+
+/* xsasl_cyrus_server_auth_response - encode server first/next response */
+
+static int xsasl_cyrus_server_auth_response(int sasl_status,
+					            SERVEROUT_TYPE serverout,
+					            unsigned serveroutlen,
+					            VSTRING *reply)
+{
+    const char *myname = "xsasl_cyrus_server_auth_response";
+    unsigned enc_length;
+    unsigned enc_length_out;
+
+    /*
+     * Encode the server first/next non-error response; otherwise return the
+     * unencoded error text that corresponds to the SASL error status.
+     * 
+     * Regarding the hairy expression below: output from sasl_encode64() comes
+     * in multiples of four bytes for each triple of input bytes, plus four
+     * bytes for any incomplete last triple, plus one byte for the null
+     * terminator.
+     */
+    if (sasl_status == SASL_OK) {
+	vstring_strcpy(reply, "");
+	return (XSASL_AUTH_DONE);
+    } else if (sasl_status == SASL_CONTINUE) {
+	if (msg_verbose)
+	    msg_info("%s: uncoded server challenge: %.*s",
+		     myname, (int) serveroutlen, serverout);
+	enc_length = ((serveroutlen + 2) / 3) * 4 + 1;
+	VSTRING_RESET(reply);			/* Fix 200512 */
+	VSTRING_SPACE(reply, enc_length);
+	if ((sasl_status = sasl_encode64(serverout, serveroutlen,
+					 STR(reply), vstring_avail(reply),
+					 &enc_length_out)) != SASL_OK)
+	    msg_panic("%s: sasl_encode64 botch: %s",
+		      myname, xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_MORE);
+    } else {
+	if (sasl_status == SASL_NOUSER)		/* privacy */
+	    sasl_status = SASL_BADAUTH;
+	vstring_strcpy(reply, xsasl_cyrus_strerror(sasl_status));
+	switch (sasl_status) {
+	case SASL_FAIL:
+	case SASL_NOMEM:
+	case SASL_TRYAGAIN:
+	case SASL_UNAVAIL:
+	    return XSASL_AUTH_TEMP;
+	default:
+	    return (XSASL_AUTH_FAIL);
+	}
+    }
+}
+
+/* xsasl_cyrus_server_first - per-session authentication */
+
+int     xsasl_cyrus_server_first(XSASL_SERVER *xp, const char *sasl_method,
+			          const char *init_response, VSTRING *reply)
+{
+    const char *myname = "xsasl_cyrus_server_first";
+    XSASL_CYRUS_SERVER *server = (XSASL_CYRUS_SERVER *) xp;
+    char   *dec_buffer;
+    unsigned dec_length;
+    unsigned reply_len;
+    unsigned serveroutlen;
+    int     sasl_status;
+    SERVEROUT_TYPE serverout = 0;
+    int     xsasl_status;
+
+#if SASL_VERSION_MAJOR < 2
+    const char *errstr = 0;
+
+#endif
+
+#define IFELSE(e1,e2,e3) ((e1) ? (e2) : (e3))
+
+    if (msg_verbose)
+	msg_info("%s: sasl_method %s%s%s", myname, sasl_method,
+		 IFELSE(init_response, ", init_response ", ""),
+		 IFELSE(init_response, init_response, ""));
+
+    /*
+     * SASL authentication protocol start-up. Process any initial client
+     * response that was sent along in the AUTH command.
+     */
+    if (init_response) {
+	reply_len = strlen(init_response);
+	VSTRING_RESET(server->decoded);		/* Fix 200512 */
+	VSTRING_SPACE(server->decoded, reply_len);
+	if ((sasl_status = SASL_DECODE64(init_response, reply_len,
+					 dec_buffer = STR(server->decoded),
+					 vstring_avail(server->decoded),
+					 &dec_length)) != SASL_OK) {
+	    vstring_strcpy(reply, xsasl_cyrus_strerror(sasl_status));
+	    return (XSASL_AUTH_FORM);
+	}
+	if (msg_verbose)
+	    msg_info("%s: decoded initial response %s", myname, dec_buffer);
+    } else {
+	dec_buffer = 0;
+	dec_length = 0;
+    }
+    sasl_status = SASL_SERVER_START(server->sasl_conn, sasl_method, dec_buffer,
+				    dec_length, &serverout,
+				    &serveroutlen, &errstr);
+    xsasl_status = xsasl_cyrus_server_auth_response(sasl_status, serverout,
+						    serveroutlen, reply);
+#if SASL_VERSION_MAJOR < 2
+    /* SASL version 1 doesn't free memory that it allocates. */
+    free(serverout);
+#endif
+    return (xsasl_status);
+}
+
+/* xsasl_cyrus_server_next - continue authentication */
+
+static int xsasl_cyrus_server_next(XSASL_SERVER *xp, const char *request,
+				           VSTRING *reply)
+{
+    const char *myname = "xsasl_cyrus_server_next";
+    XSASL_CYRUS_SERVER *server = (XSASL_CYRUS_SERVER *) xp;
+    unsigned dec_length;
+    unsigned request_len;
+    unsigned serveroutlen;
+    int     sasl_status;
+    SERVEROUT_TYPE serverout = 0;
+    int     xsasl_status;
+
+#if SASL_VERSION_MAJOR < 2
+    const char *errstr = 0;
+
+#endif
+
+    request_len = strlen(request);
+    VSTRING_RESET(server->decoded);		/* Fix 200512 */
+    VSTRING_SPACE(server->decoded, request_len);
+    if ((sasl_status = SASL_DECODE64(request, request_len,
+				     STR(server->decoded),
+				     vstring_avail(server->decoded),
+				     &dec_length)) != SASL_OK) {
+	vstring_strcpy(reply, xsasl_cyrus_strerror(sasl_status));
+	return (XSASL_AUTH_FORM);
+    }
+    if (msg_verbose)
+	msg_info("%s: decoded response: %.*s",
+		 myname, (int) dec_length, STR(server->decoded));
+    sasl_status = SASL_SERVER_STEP(server->sasl_conn, STR(server->decoded),
+				   dec_length, &serverout,
+				   &serveroutlen, &errstr);
+    xsasl_status = xsasl_cyrus_server_auth_response(sasl_status, serverout,
+						    serveroutlen, reply);
+#if SASL_VERSION_MAJOR < 2
+    /* SASL version 1 doesn't free memory that it allocates. */
+    free(serverout);
+#endif
+    return (xsasl_status);
+}
+
+/* xsasl_cyrus_server_get_username - get authenticated username */
+
+static const char *xsasl_cyrus_server_get_username(XSASL_SERVER *xp)
+{
+    const char *myname = "xsasl_cyrus_server_get_username";
+    XSASL_CYRUS_SERVER *server = (XSASL_CYRUS_SERVER *) xp;
+    VOID_SERVEROUT_TYPE serverout = 0;
+    int     sasl_status;
+
+    /*
+     * XXX Do not free(serverout).
+     */
+    sasl_status = sasl_getprop(server->sasl_conn, SASL_USERNAME, &serverout);
+    if (sasl_status != SASL_OK || serverout == 0) {
+	msg_warn("%s: sasl_getprop SASL_USERNAME botch: %s",
+		 myname, xsasl_cyrus_strerror(sasl_status));
+	return (0);
+    }
+    if (server->username)
+	myfree(server->username);
+    server->username = mystrdup(serverout);
+    printable(server->username, '?');
+    return (server->username);
+}
+
+#endif
diff --git a/src/xsasl/xsasl_dovecot.h b/src/xsasl/xsasl_dovecot.h
new file mode 100644
index 0000000..f99850e
--- /dev/null
+++ b/src/xsasl/xsasl_dovecot.h
@@ -0,0 +1,41 @@
+#ifndef _XSASL_DOVECOT_H_INCLUDED_
+#define _XSASL_DOVECOT_H_INCLUDED_
+
+/*++
+/* NAME
+/*	xsasl_dovecot 3h
+/* SUMMARY
+/*	Dovecot SASL plug-in
+/* SYNOPSIS
+/*	#include <xsasl_dovecot.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * XSASL library.
+  */
+#include <xsasl.h>
+
+#if defined(USE_SASL_AUTH)
+
+ /*
+  * SASL protocol interface
+  */
+#define XSASL_TYPE_DOVECOT "dovecot"
+
+extern XSASL_SERVER_IMPL *xsasl_dovecot_server_init(const char *, const char *);
+
+#endif
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+#endif
diff --git a/src/xsasl/xsasl_dovecot_server.c b/src/xsasl/xsasl_dovecot_server.c
new file mode 100644
index 0000000..601f787
--- /dev/null
+++ b/src/xsasl/xsasl_dovecot_server.c
@@ -0,0 +1,746 @@
+/*++
+/* NAME
+/*	xsasl_dovecot_server 3
+/* SUMMARY
+/*	Dovecot SASL server-side plug-in
+/* SYNOPSIS
+/*	XSASL_SERVER_IMPL *xsasl_dovecot_server_init(server_type, appl_name)
+/*	const char *server_type;
+/*	const char *appl_name;
+/* DESCRIPTION
+/*	This module implements the Dovecot SASL server-side authentication
+/*	plug-in.
+/*
+/* .IP server_type
+/*	The plug-in type that was specified to xsasl_server_init().
+/*	The argument is ignored, because the Dovecot plug-in
+/*	implements only one plug-in type.
+/* .IP path_info
+/*	The location of the Dovecot authentication server's UNIX-domain
+/*	socket. Note: the Dovecot plug-in uses late binding, therefore
+/*	all connect operations are done with Postfix privileges.
+/* DIAGNOSTICS
+/*	Fatal: out of memory.
+/*
+/*	Panic: interface violation.
+/*
+/*	Other: the routines log a warning and return an error result
+/*	as specified in xsasl_server(3).
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Initial implementation by:
+/*	Timo Sirainen
+/*	Procontrol
+/*	Finland
+/*
+/*	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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef STRCASECMP_IN_STRINGS_H
+#include <strings.h>
+#endif
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <connect.h>
+#include <split_at.h>
+#include <stringops.h>
+#include <vstream.h>
+#include <vstring_vstream.h>
+#include <name_mask.h>
+#include <argv.h>
+#include <myaddrinfo.h>
+
+/* Global library. */
+
+#include <mail_params.h>
+
+/* Application-specific. */
+
+#include <xsasl.h>
+#include <xsasl_dovecot.h>
+
+#ifdef USE_SASL_AUTH
+
+/* Major version changes are not backwards compatible,
+   minor version numbers can be ignored. */
+#define AUTH_PROTOCOL_MAJOR_VERSION 1
+#define AUTH_PROTOCOL_MINOR_VERSION 0
+
+ /*
+  * Encorce read/write time limits, so that we can produce accurate
+  * diagnostics instead of getting killed by the watchdog timer.
+  */
+#define AUTH_TIMEOUT	10
+
+ /*
+  * Security property bitmasks.
+  */
+#define SEC_PROPS_NOPLAINTEXT	(1 << 0)
+#define SEC_PROPS_NOACTIVE	(1 << 1)
+#define SEC_PROPS_NODICTIONARY	(1 << 2)
+#define SEC_PROPS_NOANONYMOUS	(1 << 3)
+#define SEC_PROPS_FWD_SECRECY	(1 << 4)
+#define SEC_PROPS_MUTUAL_AUTH	(1 << 5)
+#define SEC_PROPS_PRIVATE	(1 << 6)
+
+#define SEC_PROPS_POS_MASK	(SEC_PROPS_MUTUAL_AUTH | SEC_PROPS_FWD_SECRECY)
+#define SEC_PROPS_NEG_MASK	(SEC_PROPS_NOPLAINTEXT | SEC_PROPS_NOACTIVE | \
+				SEC_PROPS_NODICTIONARY | SEC_PROPS_NOANONYMOUS)
+
+ /*
+  * Security properties as specified in the Postfix main.cf file.
+  */
+static const NAME_MASK xsasl_dovecot_conf_sec_props[] = {
+    "noplaintext", SEC_PROPS_NOPLAINTEXT,
+    "noactive", SEC_PROPS_NOACTIVE,
+    "nodictionary", SEC_PROPS_NODICTIONARY,
+    "noanonymous", SEC_PROPS_NOANONYMOUS,
+    "forward_secrecy", SEC_PROPS_FWD_SECRECY,
+    "mutual_auth", SEC_PROPS_MUTUAL_AUTH,
+    0, 0,
+};
+
+ /*
+  * Security properties as specified in the Dovecot protocol. See
+  * http://wiki.dovecot.org/Authentication_Protocol.
+  */
+static const NAME_MASK xsasl_dovecot_serv_sec_props[] = {
+    "plaintext", SEC_PROPS_NOPLAINTEXT,
+    "active", SEC_PROPS_NOACTIVE,
+    "dictionary", SEC_PROPS_NODICTIONARY,
+    "anonymous", SEC_PROPS_NOANONYMOUS,
+    "forward-secrecy", SEC_PROPS_FWD_SECRECY,
+    "mutual-auth", SEC_PROPS_MUTUAL_AUTH,
+    "private", SEC_PROPS_PRIVATE,
+    0, 0,
+};
+
+ /*
+  * Class variables.
+  */
+typedef struct XSASL_DCSRV_MECH {
+    char   *mech_name;			/* mechanism name */
+    int     sec_props;			/* mechanism properties */
+    struct XSASL_DCSRV_MECH *next;
+} XSASL_DCSRV_MECH;
+
+typedef struct {
+    XSASL_SERVER_IMPL xsasl;
+    VSTREAM *sasl_stream;
+    char   *socket_path;
+    XSASL_DCSRV_MECH *mechanism_list;	/* unfiltered mechanism list */
+    unsigned int request_id_counter;
+} XSASL_DOVECOT_SERVER_IMPL;
+
+ /*
+  * The XSASL_DOVECOT_SERVER object is derived from the generic XSASL_SERVER
+  * object.
+  */
+typedef struct {
+    XSASL_SERVER xsasl;			/* generic members, must be first */
+    XSASL_DOVECOT_SERVER_IMPL *impl;
+    unsigned int last_request_id;
+    char   *service;
+    char   *username;			/* authenticated user */
+    VSTRING *sasl_line;
+    unsigned int sec_props;		/* Postfix mechanism filter */
+    int     tls_flag;			/* TLS enabled in this session */
+    char   *mechanism_list;		/* filtered mechanism list */
+    ARGV   *mechanism_argv;		/* ditto */
+    char   *client_addr;		/* remote IP address */
+    char   *server_addr;		/* remote IP address */
+} XSASL_DOVECOT_SERVER;
+
+ /*
+  * Forward declarations.
+  */
+static void xsasl_dovecot_server_done(XSASL_SERVER_IMPL *);
+static XSASL_SERVER *xsasl_dovecot_server_create(XSASL_SERVER_IMPL *,
+					        XSASL_SERVER_CREATE_ARGS *);
+static void xsasl_dovecot_server_free(XSASL_SERVER *);
+static int xsasl_dovecot_server_first(XSASL_SERVER *, const char *,
+				              const char *, VSTRING *);
+static int xsasl_dovecot_server_next(XSASL_SERVER *, const char *, VSTRING *);
+static const char *xsasl_dovecot_server_get_mechanism_list(XSASL_SERVER *);
+static const char *xsasl_dovecot_server_get_username(XSASL_SERVER *);
+
+/* xsasl_dovecot_server_mech_append - append server mechanism entry */
+
+static void xsasl_dovecot_server_mech_append(XSASL_DCSRV_MECH **mech_list,
+			               const char *mech_name, int sec_props)
+{
+    XSASL_DCSRV_MECH **mpp;
+    XSASL_DCSRV_MECH *mp;
+
+    for (mpp = mech_list; *mpp != 0; mpp = &mpp[0]->next)
+	 /* void */ ;
+
+    mp = (XSASL_DCSRV_MECH *) mymalloc(sizeof(*mp));
+    mp->mech_name = mystrdup(mech_name);
+    mp->sec_props = sec_props;
+    mp->next = 0;
+    *mpp = mp;
+}
+
+/* xsasl_dovecot_server_mech_free - destroy server mechanism list */
+
+static void xsasl_dovecot_server_mech_free(XSASL_DCSRV_MECH *mech_list)
+{
+    XSASL_DCSRV_MECH *mp;
+    XSASL_DCSRV_MECH *next;
+
+    for (mp = mech_list; mp != 0; mp = next) {
+	myfree(mp->mech_name);
+	next = mp->next;
+	myfree((void *) mp);
+    }
+}
+
+/* xsasl_dovecot_server_mech_filter - filter server mechanism list */
+
+static char *xsasl_dovecot_server_mech_filter(ARGV *mechanism_argv,
+				           XSASL_DCSRV_MECH *mechanism_list,
+					            unsigned int conf_props)
+{
+    const char *myname = "xsasl_dovecot_server_mech_filter";
+    unsigned int pos_conf_props = (conf_props & SEC_PROPS_POS_MASK);
+    unsigned int neg_conf_props = (conf_props & SEC_PROPS_NEG_MASK);
+    VSTRING *mechanisms_str = vstring_alloc(10);
+    XSASL_DCSRV_MECH *mp;
+
+    /*
+     * Match Postfix properties against Dovecot server properties.
+     */
+    for (mp = mechanism_list; mp != 0; mp = mp->next) {
+	if ((mp->sec_props & pos_conf_props) == pos_conf_props
+	    && (mp->sec_props & neg_conf_props) == 0) {
+	    if (VSTRING_LEN(mechanisms_str) > 0)
+		VSTRING_ADDCH(mechanisms_str, ' ');
+	    vstring_strcat(mechanisms_str, mp->mech_name);
+	    argv_add(mechanism_argv, mp->mech_name, (char *) 0);
+	    if (msg_verbose)
+		msg_info("%s: keep mechanism: %s", myname, mp->mech_name);
+	} else {
+	    if (msg_verbose)
+		msg_info("%s: skip mechanism: %s", myname, mp->mech_name);
+	}
+    }
+    return (vstring_export(mechanisms_str));
+}
+
+/* xsasl_dovecot_server_connect - initial auth server handshake */
+
+static int xsasl_dovecot_server_connect(XSASL_DOVECOT_SERVER_IMPL *xp)
+{
+    const char *myname = "xsasl_dovecot_server_connect";
+    VSTRING *line_str;
+    VSTREAM *sasl_stream;
+    char   *line, *cmd, *mech_name;
+    unsigned int major_version, minor_version;
+    int     fd, success, have_mech_line;
+    int     sec_props;
+    const char *path;
+
+    if (msg_verbose)
+	msg_info("%s: Connecting", myname);
+
+    /*
+     * Not documented, but necessary for testing.
+     */
+    path = xp->socket_path;
+    if (strncmp(path, "inet:", 5) == 0) {
+	fd = inet_connect(path + 5, BLOCKING, AUTH_TIMEOUT);
+    } else {
+	if (strncmp(path, "unix:", 5) == 0)
+	    path += 5;
+	fd = unix_connect(path, BLOCKING, AUTH_TIMEOUT);
+    }
+    if (fd < 0) {
+	msg_warn("SASL: Connect to %s failed: %m", xp->socket_path);
+	return (-1);
+    }
+    sasl_stream = vstream_fdopen(fd, O_RDWR);
+    vstream_control(sasl_stream,
+		    CA_VSTREAM_CTL_PATH(xp->socket_path),
+		    CA_VSTREAM_CTL_TIMEOUT(AUTH_TIMEOUT),
+		    CA_VSTREAM_CTL_END);
+
+    /* XXX Encapsulate for logging. */
+    vstream_fprintf(sasl_stream,
+		    "VERSION\t%u\t%u\n"
+		    "CPID\t%u\n",
+		    AUTH_PROTOCOL_MAJOR_VERSION,
+		    AUTH_PROTOCOL_MINOR_VERSION,
+		    (unsigned int) getpid());
+    if (vstream_fflush(sasl_stream) == VSTREAM_EOF) {
+	msg_warn("SASL: Couldn't send handshake: %m");
+	return (-1);
+    }
+    success = 0;
+    have_mech_line = 0;
+    line_str = vstring_alloc(256);
+    /* XXX Encapsulate for logging. */
+    while (vstring_get_nonl(line_str, sasl_stream) != VSTREAM_EOF) {
+	line = vstring_str(line_str);
+
+	if (msg_verbose)
+	    msg_info("%s: auth reply: %s", myname, line);
+
+	cmd = line;
+	line = split_at(line, '\t');
+
+	if (strcmp(cmd, "VERSION") == 0) {
+	    if (sscanf(line, "%u\t%u", &major_version, &minor_version) != 2) {
+		msg_warn("SASL: Protocol version error");
+		break;
+	    }
+	    if (major_version != AUTH_PROTOCOL_MAJOR_VERSION) {
+		/* Major version is different from ours. */
+		msg_warn("SASL: Protocol version mismatch (%d vs. %d)",
+			 major_version, AUTH_PROTOCOL_MAJOR_VERSION);
+		break;
+	    }
+	} else if (strcmp(cmd, "MECH") == 0 && line != NULL) {
+	    mech_name = line;
+	    have_mech_line = 1;
+	    line = split_at(line, '\t');
+	    if (line != 0) {
+		sec_props =
+		    name_mask_delim_opt(myname,
+					xsasl_dovecot_serv_sec_props,
+					line, "\t",
+				     NAME_MASK_ANY_CASE | NAME_MASK_IGNORE);
+		if ((sec_props & SEC_PROPS_PRIVATE) != 0)
+		    continue;
+	    } else
+		sec_props = 0;
+	    xsasl_dovecot_server_mech_append(&xp->mechanism_list, mech_name,
+					     sec_props);
+	} else if (strcmp(cmd, "SPID") == 0) {
+
+	    /*
+	     * Unfortunately the auth protocol handshake wasn't designed well
+	     * to differentiate between auth-client/userdb/master.
+	     * auth-userdb and auth-master send VERSION + SPID lines only and
+	     * nothing afterwards, while auth-client sends VERSION + MECH +
+	     * SPID + CUID + more. The simplest way that we can determine if
+	     * we've connected to the correct socket is to see if MECH line
+	     * exists or not (alternatively we'd have to have a small timeout
+	     * after SPID to see if CUID is sent or not).
+	     */
+	    if (!have_mech_line) {
+		msg_warn("SASL: Connected to wrong auth socket (auth-master instead of auth-client)");
+		break;
+	    }
+	} else if (strcmp(cmd, "DONE") == 0) {
+	    /* Handshake finished. */
+	    success = 1;
+	    break;
+	} else {
+	    /* ignore any unknown commands */
+	}
+    }
+    vstring_free(line_str);
+
+    if (!success) {
+	/* handshake failed */
+	(void) vstream_fclose(sasl_stream);
+	return (-1);
+    }
+    xp->sasl_stream = sasl_stream;
+    return (0);
+}
+
+/* xsasl_dovecot_server_disconnect - dispose of server connection state */
+
+static void xsasl_dovecot_server_disconnect(XSASL_DOVECOT_SERVER_IMPL *xp)
+{
+    if (xp->sasl_stream) {
+	(void) vstream_fclose(xp->sasl_stream);
+	xp->sasl_stream = 0;
+    }
+    if (xp->mechanism_list) {
+	xsasl_dovecot_server_mech_free(xp->mechanism_list);
+	xp->mechanism_list = 0;
+    }
+}
+
+/* xsasl_dovecot_server_init - create implementation handle */
+
+XSASL_SERVER_IMPL *xsasl_dovecot_server_init(const char *server_type,
+					             const char *path_info)
+{
+    XSASL_DOVECOT_SERVER_IMPL *xp;
+
+    xp = (XSASL_DOVECOT_SERVER_IMPL *) mymalloc(sizeof(*xp));
+    xp->xsasl.create = xsasl_dovecot_server_create;
+    xp->xsasl.done = xsasl_dovecot_server_done;
+    xp->socket_path = mystrdup(path_info);
+    xp->sasl_stream = 0;
+    xp->mechanism_list = 0;
+    xp->request_id_counter = 0;
+    return (&xp->xsasl);
+}
+
+/* xsasl_dovecot_server_done - dispose of implementation */
+
+static void xsasl_dovecot_server_done(XSASL_SERVER_IMPL *impl)
+{
+    XSASL_DOVECOT_SERVER_IMPL *xp = (XSASL_DOVECOT_SERVER_IMPL *) impl;
+
+    xsasl_dovecot_server_disconnect(xp);
+    myfree(xp->socket_path);
+    myfree((void *) impl);
+}
+
+/* xsasl_dovecot_server_create - create server instance */
+
+static XSASL_SERVER *xsasl_dovecot_server_create(XSASL_SERVER_IMPL *impl,
+				             XSASL_SERVER_CREATE_ARGS *args)
+{
+    const char *myname = "xsasl_dovecot_server_create";
+    XSASL_DOVECOT_SERVER *server;
+    struct sockaddr_storage ss;
+    struct sockaddr *sa = (struct sockaddr *) &ss;
+    SOCKADDR_SIZE salen;
+    MAI_HOSTADDR_STR server_addr;
+
+    if (msg_verbose)
+	msg_info("%s: SASL service=%s, realm=%s",
+		 myname, args->service, args->user_realm ?
+		 args->user_realm : "(null)");
+
+    /*
+     * Extend the XSASL_SERVER_IMPL object with our own data. We use
+     * long-lived conversion buffers rather than local variables to avoid
+     * memory leaks in case of read/write timeout or I/O error.
+     */
+    server = (XSASL_DOVECOT_SERVER *) mymalloc(sizeof(*server));
+    server->xsasl.free = xsasl_dovecot_server_free;
+    server->xsasl.first = xsasl_dovecot_server_first;
+    server->xsasl.next = xsasl_dovecot_server_next;
+    server->xsasl.get_mechanism_list = xsasl_dovecot_server_get_mechanism_list;
+    server->xsasl.get_username = xsasl_dovecot_server_get_username;
+    server->impl = (XSASL_DOVECOT_SERVER_IMPL *) impl;
+    server->sasl_line = vstring_alloc(256);
+    server->username = 0;
+    server->service = mystrdup(args->service);
+    server->last_request_id = 0;
+    server->mechanism_list = 0;
+    server->mechanism_argv = 0;
+    server->tls_flag = args->tls_flag;
+    server->sec_props =
+	name_mask_opt(myname, xsasl_dovecot_conf_sec_props,
+		      args->security_options,
+		      NAME_MASK_ANY_CASE | NAME_MASK_FATAL);
+    server->client_addr = mystrdup(args->client_addr);
+
+    /*
+     * XXX Temporary code until smtpd_peer.c is updated.
+     */
+    if (args->server_addr && *args->server_addr) {
+	server->server_addr = mystrdup(args->server_addr);
+    } else {
+	salen = sizeof(ss);
+	if (getsockname(vstream_fileno(args->stream), sa, &salen) < 0
+	    || sockaddr_to_hostaddr(sa, salen, &server_addr, 0, 0) != 0)
+	    server_addr.buf[0] = 0;
+	server->server_addr = mystrdup(server_addr.buf);
+    }
+
+    return (&server->xsasl);
+}
+
+/* xsasl_dovecot_server_get_mechanism_list - get available mechanisms */
+
+static const char *xsasl_dovecot_server_get_mechanism_list(XSASL_SERVER *xp)
+{
+    XSASL_DOVECOT_SERVER *server = (XSASL_DOVECOT_SERVER *) xp;
+
+    if (!server->impl->sasl_stream) {
+	if (xsasl_dovecot_server_connect(server->impl) < 0)
+	    return (0);
+    }
+    if (server->mechanism_list == 0) {
+	server->mechanism_argv = argv_alloc(2);
+	server->mechanism_list =
+	    xsasl_dovecot_server_mech_filter(server->mechanism_argv,
+					     server->impl->mechanism_list,
+					     server->sec_props);
+    }
+    return (server->mechanism_list[0] ? server->mechanism_list : 0);
+}
+
+/* xsasl_dovecot_server_free - destroy server instance */
+
+static void xsasl_dovecot_server_free(XSASL_SERVER *xp)
+{
+    XSASL_DOVECOT_SERVER *server = (XSASL_DOVECOT_SERVER *) xp;
+
+    vstring_free(server->sasl_line);
+    if (server->username)
+	myfree(server->username);
+    if (server->mechanism_list) {
+	myfree(server->mechanism_list);
+	argv_free(server->mechanism_argv);
+    }
+    myfree(server->service);
+    myfree(server->server_addr);
+    myfree(server->client_addr);
+    myfree((void *) server);
+}
+
+/* xsasl_dovecot_server_auth_response - encode server first/next response */
+
+static int xsasl_dovecot_parse_reply(XSASL_DOVECOT_SERVER *server, char **line)
+{
+    char   *id;
+
+    if (*line == NULL) {
+	msg_warn("SASL: Protocol error");
+	return -1;
+    }
+    id = *line;
+    *line = split_at(*line, '\t');
+
+    if (strtoul(id, NULL, 0) != server->last_request_id) {
+	/* reply to another request, shouldn't really happen.. */
+	return -1;
+    }
+    return 0;
+}
+
+static void xsasl_dovecot_parse_reply_args(XSASL_DOVECOT_SERVER *server,
+					         char *line, VSTRING *reply,
+					           int success)
+{
+    char   *next;
+
+    if (server->username) {
+	myfree(server->username);
+	server->username = 0;
+    }
+
+    /*
+     * Note: TAB is part of the Dovecot protocol and must not appear in
+     * legitimate Dovecot usernames, otherwise the protocol would break.
+     */
+    for (; line != NULL; line = next) {
+	next = split_at(line, '\t');
+	if (strncmp(line, "user=", 5) == 0) {
+	    server->username = mystrdup(line + 5);
+	    printable(server->username, '?');
+	} else if (strncmp(line, "reason=", 7) == 0) {
+	    if (!success) {
+		printable(line + 7, '?');
+		vstring_strcpy(reply, line + 7);
+	    }
+	}
+    }
+}
+
+/* xsasl_dovecot_handle_reply - receive and process auth reply */
+
+static int xsasl_dovecot_handle_reply(XSASL_DOVECOT_SERVER *server,
+				              VSTRING *reply)
+{
+    const char *myname = "xsasl_dovecot_handle_reply";
+    char   *line, *cmd;
+
+    /* XXX Encapsulate for logging. */
+    while (vstring_get_nonl(server->sasl_line,
+			    server->impl->sasl_stream) != VSTREAM_EOF) {
+	line = vstring_str(server->sasl_line);
+
+	if (msg_verbose)
+	    msg_info("%s: auth reply: %s", myname, line);
+
+	cmd = line;
+	line = split_at(line, '\t');
+
+	if (strcmp(cmd, "OK") == 0) {
+	    if (xsasl_dovecot_parse_reply(server, &line) == 0) {
+		/* authentication successful */
+		xsasl_dovecot_parse_reply_args(server, line, reply, 1);
+		if (server->username == 0) {
+		    msg_warn("missing Dovecot server %s username field", cmd);
+		    vstring_strcpy(reply, "Authentication backend error");
+		    return XSASL_AUTH_FAIL;
+		}
+		return XSASL_AUTH_DONE;
+	    }
+	} else if (strcmp(cmd, "CONT") == 0) {
+	    if (xsasl_dovecot_parse_reply(server, &line) == 0) {
+		if (line == 0) {
+		    msg_warn("missing Dovecot server %s reply field", cmd);
+		    vstring_strcpy(reply, "Authentication backend error");
+		    return XSASL_AUTH_FAIL;
+		}
+		vstring_strcpy(reply, line);
+		return XSASL_AUTH_MORE;
+	    }
+	} else if (strcmp(cmd, "FAIL") == 0) {
+	    if (xsasl_dovecot_parse_reply(server, &line) == 0) {
+		/* authentication failure */
+		xsasl_dovecot_parse_reply_args(server, line, reply, 0);
+		return XSASL_AUTH_FAIL;
+	    }
+	} else {
+	    /* ignore */
+	}
+    }
+
+    vstring_strcpy(reply, "Connection lost to authentication server");
+    return XSASL_AUTH_TEMP;
+}
+
+/* is_valid_base64 - input sanitized */
+
+static int is_valid_base64(const char *data)
+{
+
+    /*
+     * XXX Maybe use ISALNUM() (isascii && isalnum, i.e. locale independent).
+     */
+    for (; *data != '\0'; data++) {
+	if (!((*data >= '0' && *data <= '9') ||
+	      (*data >= 'a' && *data <= 'z') ||
+	      (*data >= 'A' && *data <= 'Z') ||
+	      *data == '+' || *data == '/' || *data == '='))
+	    return 0;
+    }
+    return 1;
+}
+
+/* xsasl_dovecot_server_first - per-session authentication */
+
+int     xsasl_dovecot_server_first(XSASL_SERVER *xp, const char *sasl_method,
+			          const char *init_response, VSTRING *reply)
+{
+    const char *myname = "xsasl_dovecot_server_first";
+    XSASL_DOVECOT_SERVER *server = (XSASL_DOVECOT_SERVER *) xp;
+    int     i;
+    char  **cpp;
+
+#define IFELSE(e1,e2,e3) ((e1) ? (e2) : (e3))
+
+    if (msg_verbose)
+	msg_info("%s: sasl_method %s%s%s", myname, sasl_method,
+		 IFELSE(init_response, ", init_response ", ""),
+		 IFELSE(init_response, init_response, ""));
+
+    if (server->mechanism_argv == 0)
+	msg_panic("%s: no mechanism list", myname);
+
+    for (cpp = server->mechanism_argv->argv; /* see below */ ; cpp++) {
+	if (*cpp == 0) {
+	    vstring_strcpy(reply, "Invalid authentication mechanism");
+	    return XSASL_AUTH_FAIL;
+	}
+	if (strcasecmp(sasl_method, *cpp) == 0)
+	    break;
+    }
+    if (init_response)
+	if (!is_valid_base64(init_response)) {
+	    vstring_strcpy(reply, "Invalid base64 data in initial response");
+	    return XSASL_AUTH_FAIL;
+	}
+    for (i = 0; i < 2; i++) {
+	if (!server->impl->sasl_stream) {
+	    if (xsasl_dovecot_server_connect(server->impl) < 0)
+		return XSASL_AUTH_TEMP;
+	}
+	/* send the request */
+	server->last_request_id = ++server->impl->request_id_counter;
+	/* XXX Encapsulate for logging. */
+	vstream_fprintf(server->impl->sasl_stream,
+			"AUTH\t%u\t%s\tservice=%s\tnologin\tlip=%s\trip=%s",
+			server->last_request_id, sasl_method,
+			server->service, server->server_addr,
+			server->client_addr);
+	if (server->tls_flag)
+	    /* XXX Encapsulate for logging. */
+	    vstream_fputs("\tsecured", server->impl->sasl_stream);
+	if (init_response) {
+
+	    /*
+	     * initial response is already base64 encoded, so we can send it
+	     * directly.
+	     */
+	    /* XXX Encapsulate for logging. */
+	    vstream_fprintf(server->impl->sasl_stream,
+			    "\tresp=%s", init_response);
+	}
+	/* XXX Encapsulate for logging. */
+	VSTREAM_PUTC('\n', server->impl->sasl_stream);
+
+	if (vstream_fflush(server->impl->sasl_stream) != VSTREAM_EOF)
+	    break;
+
+	if (i == 1) {
+	    vstring_strcpy(reply, "Can't connect to authentication server");
+	    return XSASL_AUTH_TEMP;
+	}
+
+	/*
+	 * Reconnect and try again.
+	 */
+	xsasl_dovecot_server_disconnect(server->impl);
+    }
+
+    return xsasl_dovecot_handle_reply(server, reply);
+}
+
+/* xsasl_dovecot_server_next - continue authentication */
+
+static int xsasl_dovecot_server_next(XSASL_SERVER *xp, const char *request,
+				             VSTRING *reply)
+{
+    XSASL_DOVECOT_SERVER *server = (XSASL_DOVECOT_SERVER *) xp;
+
+    if (!is_valid_base64(request)) {
+	vstring_strcpy(reply, "Invalid base64 data in continued response");
+	return XSASL_AUTH_FAIL;
+    }
+    /* XXX Encapsulate for logging. */
+    vstream_fprintf(server->impl->sasl_stream,
+		    "CONT\t%u\t%s\n", server->last_request_id, request);
+    if (vstream_fflush(server->impl->sasl_stream) == VSTREAM_EOF) {
+	vstring_strcpy(reply, "Connection lost to authentication server");
+	return XSASL_AUTH_TEMP;
+    }
+    return xsasl_dovecot_handle_reply(server, reply);
+}
+
+/* xsasl_dovecot_server_get_username - get authenticated username */
+
+static const char *xsasl_dovecot_server_get_username(XSASL_SERVER *xp)
+{
+    XSASL_DOVECOT_SERVER *server = (XSASL_DOVECOT_SERVER *) xp;
+
+    return (server->username);
+}
+
+#endif
diff --git a/src/xsasl/xsasl_server.c b/src/xsasl/xsasl_server.c
new file mode 100644
index 0000000..e8d7e16
--- /dev/null
+++ b/src/xsasl/xsasl_server.c
@@ -0,0 +1,270 @@
+/*++
+/* NAME
+/*	xsasl-server 3
+/* SUMMARY
+/*	Postfix SASL server plug-in interface
+/* SYNOPSIS
+/*	#include <xsasl.h>
+/*
+/*	XSASL_SERVER_IMPL *xsasl_server_init(server_type, path_info)
+/*	const char *server_type;
+/*	const char *path_info;
+/*
+/*	void	xsasl_server_done(implementation)
+/*	XSASL_SERVER_IMPL *implementation;
+/*
+/*	ARGV	*xsasl_server_types()
+/*
+/* .in +4
+/*	typedef struct XSASL_SERVER_CREATE_ARGS {
+/*		VSTREAM *stream;
+/*		const char *server_addr;
+/*		const char *client_addr;
+/*		const char *service;
+/*		const char *user_realm;
+/*		const char *security_options;
+/*		int     tls_flag;
+/*	} XSASL_SERVER_CREATE_ARGS;
+/* .in -4
+/*
+/*	XSASL_SERVER *xsasl_server_create(implementation, args)
+/*	XSASL_SERVER_IMPL *implementation;
+/*	XSASL_SERVER_CREATE_ARGS *args;
+/*
+/*	XSASL_SERVER *XSASL_SERVER_CREATE(implementation, args,
+/*					stream = stream_value,
+/*					...,
+/*					tls_flag = tls_flag_value)
+/*	XSASL_SERVER_IMPL *implementation;
+/*	XSASL_SERVER_CREATE_ARGS *args;
+/*
+/*	void xsasl_server_free(server)
+/*	XSASL_SERVER *server;
+/*
+/*	int	xsasl_server_first(server, auth_method, init_resp, server_reply)
+/*	XSASL_SERVER *server;
+/*	const char *auth_method;
+/*	const char *init_resp;
+/*	VSTRING *server_reply;
+/*
+/*	int	xsasl_server_next(server, client_request, server_reply)
+/*	XSASL_SERVER *server;
+/*	const char *client_request;
+/*	VSTRING *server_reply;
+/*
+/*	const char *xsasl_server_get_mechanism_list(server)
+/*	XSASL_SERVER *server;
+/*
+/*	const char *xsasl_server_get_username(server)
+/*	XSASL_SERVER *server;
+/* DESCRIPTION
+/*	The XSASL_SERVER abstraction implements a generic interface
+/*	to one or more SASL authentication implementations.
+/*
+/*	xsasl_server_init() is called once during process initialization.
+/*	It selects a SASL implementation by name, specifies the
+/*	location of a configuration file or rendez-vous point, and
+/*	returns an implementation handle that can be used to generate
+/*	SASL server instances. This function is typically used to
+/*	initialize the underlying implementation.
+/*
+/*	xsasl_server_done() disposes of an implementation handle,
+/*	and allows the underlying implementation to release resources.
+/*
+/*	xsasl_server_types() lists the available implementation types.
+/*	The result should be destroyed by the caller.
+/*
+/*	xsasl_server_create() is called at the start of an SMTP
+/*	session. It generates a Postfix SASL plug-in server instance
+/*	for the specified service and authentication realm, and
+/*	with the specified security properties. Specify a null
+/*	pointer when no realm should be used. The stream handle is
+/*	stored so that encryption can be turned on after successful
+/*	negotiations. Specify zero-length strings when a client or
+/*	server address is unavailable.
+/*
+/*	XSASL_SERVER_CREATE() is a macro that provides an interface
+/*	with named parameters.  Named parameters do not have to
+/*	appear in a fixed order. The parameter names correspond to
+/*	the member names of the XSASL_SERVER_CREATE_ARGS structure.
+/*
+/*	xsasl_server_free() is called at the end of an SMTP session.
+/*	It destroys a SASL server instance, and disables further
+/*	read/write operations if encryption was turned on.
+/*
+/*	xsasl_server_first() produces the server response for the
+/*	client AUTH command. The client input are an authentication
+/*	method, and an optional initial response or null pointer.
+/*	The initial response and server non-error replies are BASE64
+/*	encoded.  Server error replies are 7-bit ASCII text without
+/*	control characters, without BASE64 encoding, and without
+/*	SMTP reply code or enhanced status code.
+/*
+/*	The result is one of the following:
+/* .IP XSASL_AUTH_MORE
+/*	More client input is needed. The server reply specifies
+/*	what.
+/* .IP XSASL_AUTH_DONE
+/*	Authentication completed successfully.
+/* .IP XSASL_AUTH_FORM
+/*	The client input is incorrectly formatted. The server error
+/*	reply explains why.
+/* .IP XSASL_AUTH_FAIL
+/*	Authentication failed. The server error reply explains why.
+/* .PP
+/*	xsasl_server_next() supports the subsequent stages of the
+/*	client-server AUTH protocol. Both the client input and
+/*	server non-error responses are BASE64 encoded.  See
+/*	xsasl_server_first() for other details.
+/*
+/*	xsasl_server_get_mechanism_list() returns the authentication
+/*	mechanisms that match the security properties, as a white-space
+/*	separated list. This is meant to be used in the SMTP EHLO
+/*	reply.
+/*
+/*	xsasl_server_get_username() returns the stored username
+/*	after successful authentication.
+/*
+/*	Arguments:
+/* .IP addr_family
+/*	The network address family: AF_INET6 or AF_INET.
+/* .IP auth_method
+/*	AUTH command authentication method.
+/* .IP client_addr
+/*	IPv4 or IPv6 address (no surrounding [] or ipv6: prefix),
+/*	or zero-length string if unavailable.
+/* .IP client_port
+/*	TCP port or zero-length string if unavailable.
+/* .IP init_resp
+/*	AUTH command initial response or null pointer.
+/* .IP implementation
+/*	Implementation handle that was obtained with xsasl_server_init().
+/* .IP path_info
+/*	The value of the smtpd_sasl_path parameter or equivalent.
+/*	This specifies the implementation-dependent location of a
+/*	configuration file, rendez-vous point, etc., and is passed
+/*	unchanged to the plug-in.
+/* .IP security_options
+/*	The value of the smtpd_security_options parameter or
+/*	equivalent. This is passed unchanged to the plug-in.
+/* .IP server
+/*	SASL plug-in server handle.
+/* .IP server_addr
+/*	IPv4 or IPv6 address (no surrounding [] or ipv6: prefix),
+/*	or zero-length string if unavailable.
+/* .IP server_port
+/*	TCP port or zero-length string if unavailable.
+/* .IP server_reply
+/*	BASE64 encoded server non-error reply (without SMTP reply
+/*	code or enhanced status code), or ASCII error description.
+/* .IP server_type
+/*	The name of a Postfix SASL server plug_in implementation.
+/* .IP server_types
+/*	Null-terminated array of strings with SASL server plug-in
+/*	implementation names.
+/* .IP service
+/*	The service that is implemented by the local server, typically
+/*	"smtp" or "lmtp".
+/* .IP stream
+/*	The connection between client and server.  When SASL
+/*	encryption is negotiated, the plug-in will transparently
+/*	intercept the socket read/write operations.
+/* .IP user_realm
+/*	Authentication domain or null pointer.
+/* SECURITY
+/* .ad
+/* .fi
+/*	The caller does not sanitize client input. It is the
+/*	responsibility of the underlying SASL server implementation
+/*	to produce 7-bit ASCII without control characters as server
+/*	non-error and error replies, and as the result from
+/*	xsasl_server_method() and xsasl_server_username().
+/* DIAGNOSTICS
+/*	In case of failure, xsasl_server_init(), xsasl_server_create(),
+/*	xsasl_server_get_mechanism_list() and xsasl_server_get_username()
+/*	log a warning and return a null pointer.
+/*
+/*	Functions that normally return XSASL_AUTH_OK will log a warning
+/*	and return an appropriate result value.
+/*
+/*	Fatal errors: out of memory.
+/*
+/*	Panic: interface violations.
+/* SEE ALSO
+/*	cyrus_security(3) Cyrus SASL security features
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this
+/*	software.
+/* AUTHOR(S)
+/*	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 <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+
+/* SASL implementations. */
+
+#include <xsasl.h>
+#include <xsasl_cyrus.h>
+#include <xsasl_dovecot.h>
+
+ /*
+  * Lookup table for available SASL server implementations.
+  */
+typedef struct {
+    char   *server_type;
+    struct XSASL_SERVER_IMPL *(*server_init) (const char *, const char *);
+} XSASL_SERVER_IMPL_INFO;
+
+static const XSASL_SERVER_IMPL_INFO server_impl_info[] = {
+#ifdef XSASL_TYPE_CYRUS
+    {XSASL_TYPE_CYRUS, xsasl_cyrus_server_init},
+#endif
+#ifdef XSASL_TYPE_DOVECOT
+    {XSASL_TYPE_DOVECOT, xsasl_dovecot_server_init},
+#endif
+    {0, 0}
+};
+
+/* xsasl_server_init - look up server implementation by name */
+
+XSASL_SERVER_IMPL *xsasl_server_init(const char *server_type,
+				             const char *path_info)
+{
+    const XSASL_SERVER_IMPL_INFO *xp;
+
+    for (xp = server_impl_info; xp->server_type; xp++)
+	if (strcmp(server_type, xp->server_type) == 0)
+	    return (xp->server_init(server_type, path_info));
+    msg_warn("unsupported SASL server implementation: %s", server_type);
+    return (0);
+}
+
+/* xsasl_server_types - report available implementation types */
+
+ARGV   *xsasl_server_types(void)
+{
+    const XSASL_SERVER_IMPL_INFO *xp;
+    ARGV   *argv = argv_alloc(1);
+
+    for (xp = server_impl_info; xp->server_type; xp++)
+	argv_add(argv, xp->server_type, ARGV_END);
+    return (argv);
+}