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l---------src/tlsproxy/.indent.pro1
-rw-r--r--src/tlsproxy/Makefile.in117
-rw-r--r--src/tlsproxy/tlsproxy.c1968
-rw-r--r--src/tlsproxy/tlsproxy.h69
-rw-r--r--src/tlsproxy/tlsproxy_state.c169
5 files changed, 2324 insertions, 0 deletions
diff --git a/src/tlsproxy/.indent.pro b/src/tlsproxy/.indent.pro
new file mode 120000
index 0000000..5c837ec
--- /dev/null
+++ b/src/tlsproxy/.indent.pro
@@ -0,0 +1 @@
+../../.indent.pro \ No newline at end of file
diff --git a/src/tlsproxy/Makefile.in b/src/tlsproxy/Makefile.in
new file mode 100644
index 0000000..c72aa81
--- /dev/null
+++ b/src/tlsproxy/Makefile.in
@@ -0,0 +1,117 @@
+SHELL = /bin/sh
+SRCS = tlsproxy.c tlsproxy_state.c
+OBJS = tlsproxy.o tlsproxy_state.o
+HDRS =
+TESTSRC =
+DEFS = -I. -I$(INC_DIR) -D$(SYSTYPE)
+CFLAGS = $(DEBUG) $(OPT) $(DEFS)
+TESTPROG=
+PROG = tlsproxy
+INC_DIR = ../../include
+LIBS = ../../lib/lib$(LIB_PREFIX)master$(LIB_SUFFIX) \
+ ../../lib/lib$(LIB_PREFIX)tls$(LIB_SUFFIX) \
+ ../../lib/lib$(LIB_PREFIX)dns$(LIB_SUFFIX) \
+ ../../lib/lib$(LIB_PREFIX)global$(LIB_SUFFIX) \
+ ../../lib/lib$(LIB_PREFIX)util$(LIB_SUFFIX)
+
+.c.o:; $(CC) $(CFLAGS) -c $*.c
+
+$(PROG): $(OBJS) $(LIBS)
+ $(CC) $(CFLAGS) $(SHLIB_RPATH) -o $@ $(OBJS) $(LIBS) $(SYSLIBS)
+
+$(OBJS): ../../conf/makedefs.out
+
+Makefile: Makefile.in
+ cat ../../conf/makedefs.out $? >$@
+
+test: $(TESTPROG)
+
+tests: test
+
+root_tests:
+
+update: ../../libexec/$(PROG)
+
+../../libexec/$(PROG): $(PROG)
+ cp $(PROG) ../../libexec
+
+printfck: $(OBJS) $(PROG)
+ rm -rf printfck
+ mkdir 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 *core $(PROG) $(TESTPROG) junk
+ rm -rf printfck
+
+tidy: clean
+
+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'
+tlsproxy.o: ../../include/argv.h
+tlsproxy.o: ../../include/attr.h
+tlsproxy.o: ../../include/been_here.h
+tlsproxy.o: ../../include/check_arg.h
+tlsproxy.o: ../../include/dns.h
+tlsproxy.o: ../../include/events.h
+tlsproxy.o: ../../include/htable.h
+tlsproxy.o: ../../include/iostuff.h
+tlsproxy.o: ../../include/mail_conf.h
+tlsproxy.o: ../../include/mail_params.h
+tlsproxy.o: ../../include/mail_proto.h
+tlsproxy.o: ../../include/mail_server.h
+tlsproxy.o: ../../include/mail_version.h
+tlsproxy.o: ../../include/msg.h
+tlsproxy.o: ../../include/myaddrinfo.h
+tlsproxy.o: ../../include/mymalloc.h
+tlsproxy.o: ../../include/name_code.h
+tlsproxy.o: ../../include/name_mask.h
+tlsproxy.o: ../../include/nbbio.h
+tlsproxy.o: ../../include/nvtable.h
+tlsproxy.o: ../../include/sock_addr.h
+tlsproxy.o: ../../include/split_at.h
+tlsproxy.o: ../../include/sys_defs.h
+tlsproxy.o: ../../include/tls.h
+tlsproxy.o: ../../include/tls_proxy.h
+tlsproxy.o: ../../include/vbuf.h
+tlsproxy.o: ../../include/vstream.h
+tlsproxy.o: ../../include/vstring.h
+tlsproxy.o: tlsproxy.c
+tlsproxy.o: tlsproxy.h
+tlsproxy_state.o: ../../include/argv.h
+tlsproxy_state.o: ../../include/attr.h
+tlsproxy_state.o: ../../include/check_arg.h
+tlsproxy_state.o: ../../include/dns.h
+tlsproxy_state.o: ../../include/events.h
+tlsproxy_state.o: ../../include/htable.h
+tlsproxy_state.o: ../../include/mail_conf.h
+tlsproxy_state.o: ../../include/mail_server.h
+tlsproxy_state.o: ../../include/msg.h
+tlsproxy_state.o: ../../include/myaddrinfo.h
+tlsproxy_state.o: ../../include/mymalloc.h
+tlsproxy_state.o: ../../include/name_code.h
+tlsproxy_state.o: ../../include/name_mask.h
+tlsproxy_state.o: ../../include/nbbio.h
+tlsproxy_state.o: ../../include/nvtable.h
+tlsproxy_state.o: ../../include/sock_addr.h
+tlsproxy_state.o: ../../include/sys_defs.h
+tlsproxy_state.o: ../../include/tls.h
+tlsproxy_state.o: ../../include/tls_proxy.h
+tlsproxy_state.o: ../../include/vbuf.h
+tlsproxy_state.o: ../../include/vstream.h
+tlsproxy_state.o: ../../include/vstring.h
+tlsproxy_state.o: tlsproxy.h
+tlsproxy_state.o: tlsproxy_state.c
diff --git a/src/tlsproxy/tlsproxy.c b/src/tlsproxy/tlsproxy.c
new file mode 100644
index 0000000..ccb3804
--- /dev/null
+++ b/src/tlsproxy/tlsproxy.c
@@ -0,0 +1,1968 @@
+/*++
+/* NAME
+/* tlsproxy 8
+/* SUMMARY
+/* Postfix TLS proxy
+/* SYNOPSIS
+/* \fBtlsproxy\fR [generic Postfix daemon options]
+/* DESCRIPTION
+/* The \fBtlsproxy\fR(8) server implements a two-way TLS proxy. It
+/* is used by the \fBpostscreen\fR(8) server to talk SMTP-over-TLS
+/* with remote SMTP clients that are not allowlisted (including
+/* clients whose allowlist status has expired), and by the
+/* \fBsmtp\fR(8) client to support TLS connection reuse, but it
+/* should also work for non-SMTP protocols.
+/*
+/* Although one \fBtlsproxy\fR(8) process can serve multiple
+/* sessions at the same time, it is a good idea to allow the
+/* number of processes to increase with load, so that the
+/* service remains responsive.
+/* PROTOCOL EXAMPLE
+/* .ad
+/* .fi
+/* The example below concerns \fBpostscreen\fR(8). However,
+/* the \fBtlsproxy\fR(8) server is agnostic of the application
+/* protocol, and the example is easily adapted to other
+/* applications.
+/*
+/* After receiving a valid remote SMTP client STARTTLS command,
+/* the \fBpostscreen\fR(8) server sends the remote SMTP client
+/* endpoint string, the requested role (server), and the
+/* requested timeout to \fBtlsproxy\fR(8). \fBpostscreen\fR(8)
+/* then receives a "TLS available" indication from \fBtlsproxy\fR(8).
+/* If the TLS service is available, \fBpostscreen\fR(8) sends
+/* the remote SMTP client file descriptor to \fBtlsproxy\fR(8),
+/* and sends the plaintext 220 greeting to the remote SMTP
+/* client. This triggers TLS negotiations between the remote
+/* SMTP client and \fBtlsproxy\fR(8). Upon completion of the
+/* TLS-level handshake, \fBtlsproxy\fR(8) translates between
+/* plaintext from/to \fBpostscreen\fR(8) and ciphertext to/from
+/* the remote SMTP client.
+/* SECURITY
+/* .ad
+/* .fi
+/* The \fBtlsproxy\fR(8) server is moderately security-sensitive.
+/* It talks to untrusted clients on the network. The process
+/* can be run chrooted at fixed low privilege.
+/* DIAGNOSTICS
+/* Problems and transactions are logged to \fBsyslogd\fR(8)
+/* or \fBpostlogd\fR(8).
+/* CONFIGURATION PARAMETERS
+/* .ad
+/* .fi
+/* Changes to \fBmain.cf\fR are not picked up automatically,
+/* as \fBtlsproxy\fR(8) processes may run for a long time
+/* depending on mail server load. Use the command "\fBpostfix
+/* reload\fR" to speed up a change.
+/*
+/* The text below provides only a parameter summary. See
+/* \fBpostconf\fR(5) for more details including examples.
+/* STARTTLS GLOBAL CONTROLS
+/* .ad
+/* .fi
+/* The following settings are global and therefore cannot be
+/* overruled by information specified in a \fBtlsproxy\fR(8)
+/* client request.
+/* .IP "\fBtls_append_default_CA (no)\fR"
+/* Append the system-supplied default Certification Authority
+/* certificates to the ones specified with *_tls_CApath or *_tls_CAfile.
+/* .IP "\fBtls_daemon_random_bytes (32)\fR"
+/* The number of pseudo-random bytes that an \fBsmtp\fR(8) or \fBsmtpd\fR(8)
+/* process requests from the \fBtlsmgr\fR(8) server in order to seed its
+/* internal pseudo random number generator (PRNG).
+/* .IP "\fBtls_high_cipherlist (see 'postconf -d' output)\fR"
+/* The OpenSSL cipherlist for "high" grade ciphers.
+/* .IP "\fBtls_medium_cipherlist (see 'postconf -d' output)\fR"
+/* The OpenSSL cipherlist for "medium" or higher grade ciphers.
+/* .IP "\fBtls_low_cipherlist (see 'postconf -d' output)\fR"
+/* The OpenSSL cipherlist for "low" or higher grade ciphers.
+/* .IP "\fBtls_export_cipherlist (see 'postconf -d' output)\fR"
+/* The OpenSSL cipherlist for "export" or higher grade ciphers.
+/* .IP "\fBtls_null_cipherlist (eNULL:!aNULL)\fR"
+/* The OpenSSL cipherlist for "NULL" grade ciphers that provide
+/* authentication without encryption.
+/* .IP "\fBtls_eecdh_strong_curve (prime256v1)\fR"
+/* The elliptic curve used by the Postfix SMTP server for sensibly
+/* strong
+/* ephemeral ECDH key exchange.
+/* .IP "\fBtls_eecdh_ultra_curve (secp384r1)\fR"
+/* The elliptic curve used by the Postfix SMTP server for maximally
+/* strong
+/* ephemeral ECDH key exchange.
+/* .IP "\fBtls_disable_workarounds (see 'postconf -d' output)\fR"
+/* List or bit-mask of OpenSSL bug work-arounds to disable.
+/* .IP "\fBtls_preempt_cipherlist (no)\fR"
+/* With SSLv3 and later, use the Postfix SMTP server's cipher
+/* preference order instead of the remote client's cipher preference
+/* order.
+/* .PP
+/* Available in Postfix version 2.9 and later:
+/* .IP "\fBtls_legacy_public_key_fingerprints (no)\fR"
+/* A temporary migration aid for sites that use certificate
+/* \fIpublic-key\fR fingerprints with Postfix 2.9.0..2.9.5, which use
+/* an incorrect algorithm.
+/* .PP
+/* Available in Postfix version 2.11-3.1:
+/* .IP "\fBtls_dane_digest_agility (on)\fR"
+/* Configure RFC7671 DANE TLSA digest algorithm agility.
+/* .IP "\fBtls_dane_trust_anchor_digest_enable (yes)\fR"
+/* Enable support for RFC 6698 (DANE TLSA) DNS records that contain
+/* digests of trust-anchors with certificate usage "2".
+/* .PP
+/* Available in Postfix version 2.11 and later:
+/* .IP "\fBtlsmgr_service_name (tlsmgr)\fR"
+/* The name of the \fBtlsmgr\fR(8) service entry in master.cf.
+/* .PP
+/* Available in Postfix version 3.0 and later:
+/* .IP "\fBtls_session_ticket_cipher (Postfix >= 3.0: aes-256-cbc, Postfix < 3.0: aes-128-cbc)\fR"
+/* Algorithm used to encrypt RFC5077 TLS session tickets.
+/* .IP "\fBopenssl_path (openssl)\fR"
+/* The location of the OpenSSL command line program \fBopenssl\fR(1).
+/* .PP
+/* Available in Postfix version 3.2 and later:
+/* .IP "\fBtls_eecdh_auto_curves (see 'postconf -d' output)\fR"
+/* The prioritized list of elliptic curves supported by the Postfix
+/* SMTP client and server.
+/* .PP
+/* Available in Postfix version 3.4 and later:
+/* .IP "\fBtls_server_sni_maps (empty)\fR"
+/* Optional lookup tables that map names received from remote SMTP
+/* clients via the TLS Server Name Indication (SNI) extension to the
+/* appropriate keys and certificate chains.
+/* .PP
+/* Available in Postfix 3.5, 3.4.6, 3.3.5, 3.2.10, 3.1.13 and later:
+/* .IP "\fBtls_fast_shutdown_enable (yes)\fR"
+/* A workaround for implementations that hang Postfix while shutting
+/* down a TLS session, until Postfix times out.
+/* .PP
+/* Available in Postfix 3.9, 3.8.1, 3.7.6, 3.6.10, 3.5.20 and later:
+/* .IP "\fBtls_config_file (default)\fR"
+/* Optional configuration file with baseline OpenSSL settings.
+/* .IP "\fBtls_config_name (empty)\fR"
+/* The application name passed by Postfix to OpenSSL library
+/* initialization functions.
+/* STARTTLS SERVER CONTROLS
+/* .ad
+/* .fi
+/* These settings are clones of Postfix SMTP server settings.
+/* They allow \fBtlsproxy\fR(8) to load the same certificate
+/* and private key information as the Postfix SMTP server,
+/* before dropping privileges, so that the key files can be
+/* kept read-only for root. These settings can currently not
+/* be overruled by information in a \fBtlsproxy\fR(8) client
+/* request, but that limitation may be removed in a future
+/* version.
+/* .IP "\fBtlsproxy_tls_CAfile ($smtpd_tls_CAfile)\fR"
+/* A file containing (PEM format) CA certificates of root CAs
+/* trusted to sign either remote SMTP client certificates or intermediate
+/* CA certificates.
+/* .IP "\fBtlsproxy_tls_CApath ($smtpd_tls_CApath)\fR"
+/* A directory containing (PEM format) CA certificates of root CAs
+/* trusted to sign either remote SMTP client certificates or intermediate
+/* CA certificates.
+/* .IP "\fBtlsproxy_tls_always_issue_session_ids ($smtpd_tls_always_issue_session_ids)\fR"
+/* Force the Postfix \fBtlsproxy\fR(8) server to issue a TLS session id,
+/* even when TLS session caching is turned off.
+/* .IP "\fBtlsproxy_tls_ask_ccert ($smtpd_tls_ask_ccert)\fR"
+/* Ask a remote SMTP client for a client certificate.
+/* .IP "\fBtlsproxy_tls_ccert_verifydepth ($smtpd_tls_ccert_verifydepth)\fR"
+/* The verification depth for remote SMTP client certificates.
+/* .IP "\fBtlsproxy_tls_cert_file ($smtpd_tls_cert_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) server RSA certificate in PEM
+/* format.
+/* .IP "\fBtlsproxy_tls_ciphers ($smtpd_tls_ciphers)\fR"
+/* The minimum TLS cipher grade that the Postfix \fBtlsproxy\fR(8) server
+/* will use with opportunistic TLS encryption.
+/* .IP "\fBtlsproxy_tls_dcert_file ($smtpd_tls_dcert_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) server DSA certificate in PEM
+/* format.
+/* .IP "\fBtlsproxy_tls_dh1024_param_file ($smtpd_tls_dh1024_param_file)\fR"
+/* File with DH parameters that the Postfix \fBtlsproxy\fR(8) server
+/* should use with non-export EDH ciphers.
+/* .IP "\fBtlsproxy_tls_dh512_param_file ($smtpd_tls_dh512_param_file)\fR"
+/* File with DH parameters that the Postfix \fBtlsproxy\fR(8) server
+/* should use with export-grade EDH ciphers.
+/* .IP "\fBtlsproxy_tls_dkey_file ($smtpd_tls_dkey_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) server DSA private key in PEM
+/* format.
+/* .IP "\fBtlsproxy_tls_eccert_file ($smtpd_tls_eccert_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) server ECDSA certificate in PEM
+/* format.
+/* .IP "\fBtlsproxy_tls_eckey_file ($smtpd_tls_eckey_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) server ECDSA private key in PEM
+/* format.
+/* .IP "\fBtlsproxy_tls_eecdh_grade ($smtpd_tls_eecdh_grade)\fR"
+/* The Postfix \fBtlsproxy\fR(8) server security grade for ephemeral
+/* elliptic-curve Diffie-Hellman (EECDH) key exchange.
+/* .IP "\fBtlsproxy_tls_exclude_ciphers ($smtpd_tls_exclude_ciphers)\fR"
+/* List of ciphers or cipher types to exclude from the \fBtlsproxy\fR(8)
+/* server cipher list at all TLS security levels.
+/* .IP "\fBtlsproxy_tls_fingerprint_digest ($smtpd_tls_fingerprint_digest)\fR"
+/* The message digest algorithm to construct remote SMTP
+/* client-certificate
+/* fingerprints.
+/* .IP "\fBtlsproxy_tls_key_file ($smtpd_tls_key_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) server RSA private key in PEM
+/* format.
+/* .IP "\fBtlsproxy_tls_loglevel ($smtpd_tls_loglevel)\fR"
+/* Enable additional Postfix \fBtlsproxy\fR(8) server logging of TLS
+/* activity.
+/* .IP "\fBtlsproxy_tls_mandatory_ciphers ($smtpd_tls_mandatory_ciphers)\fR"
+/* The minimum TLS cipher grade that the Postfix \fBtlsproxy\fR(8) server
+/* will use with mandatory TLS encryption.
+/* .IP "\fBtlsproxy_tls_mandatory_exclude_ciphers ($smtpd_tls_mandatory_exclude_ciphers)\fR"
+/* Additional list of ciphers or cipher types to exclude from the
+/* \fBtlsproxy\fR(8) server cipher list at mandatory TLS security levels.
+/* .IP "\fBtlsproxy_tls_mandatory_protocols ($smtpd_tls_mandatory_protocols)\fR"
+/* The SSL/TLS protocols accepted by the Postfix \fBtlsproxy\fR(8) server
+/* with mandatory TLS encryption.
+/* .IP "\fBtlsproxy_tls_protocols ($smtpd_tls_protocols)\fR"
+/* List of TLS protocols that the Postfix \fBtlsproxy\fR(8) server will
+/* exclude or include with opportunistic TLS encryption.
+/* .IP "\fBtlsproxy_tls_req_ccert ($smtpd_tls_req_ccert)\fR"
+/* With mandatory TLS encryption, require a trusted remote SMTP
+/* client certificate in order to allow TLS connections to proceed.
+/* .IP "\fBtlsproxy_tls_security_level ($smtpd_tls_security_level)\fR"
+/* The SMTP TLS security level for the Postfix \fBtlsproxy\fR(8) server;
+/* when a non-empty value is specified, this overrides the obsolete
+/* parameters smtpd_use_tls and smtpd_enforce_tls.
+/* .IP "\fBtlsproxy_tls_chain_files ($smtpd_tls_chain_files)\fR"
+/* Files with the Postfix \fBtlsproxy\fR(8) server keys and certificate
+/* chains in PEM format.
+/* STARTTLS CLIENT CONTROLS
+/* .ad
+/* .fi
+/* These settings are clones of Postfix SMTP client settings.
+/* They allow \fBtlsproxy\fR(8) to load the same certificate
+/* and private key information as the Postfix SMTP client,
+/* before dropping privileges, so that the key files can be
+/* kept read-only for root. Some settings may be overruled by
+/* information in a \fBtlsproxy\fR(8) client request.
+/* .PP
+/* Available in Postfix version 3.4 and later:
+/* .IP "\fBtlsproxy_client_CAfile ($smtp_tls_CAfile)\fR"
+/* A file containing CA certificates of root CAs trusted to sign
+/* either remote TLS server certificates or intermediate CA certificates.
+/* .IP "\fBtlsproxy_client_CApath ($smtp_tls_CApath)\fR"
+/* Directory with PEM format Certification Authority certificates
+/* that the Postfix \fBtlsproxy\fR(8) client uses to verify a remote TLS
+/* server certificate.
+/* .IP "\fBtlsproxy_client_chain_files ($smtp_tls_chain_files)\fR"
+/* Files with the Postfix \fBtlsproxy\fR(8) client keys and certificate
+/* chains in PEM format.
+/* .IP "\fBtlsproxy_client_cert_file ($smtp_tls_cert_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) client RSA certificate in PEM
+/* format.
+/* .IP "\fBtlsproxy_client_key_file ($smtp_tls_key_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) client RSA private key in PEM
+/* format.
+/* .IP "\fBtlsproxy_client_dcert_file ($smtp_tls_dcert_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) client DSA certificate in PEM
+/* format.
+/* .IP "\fBtlsproxy_client_dkey_file ($smtp_tls_dkey_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) client DSA private key in PEM
+/* format.
+/* .IP "\fBtlsproxy_client_eccert_file ($smtp_tls_eccert_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) client ECDSA certificate in PEM
+/* format.
+/* .IP "\fBtlsproxy_client_eckey_file ($smtp_tls_eckey_file)\fR"
+/* File with the Postfix \fBtlsproxy\fR(8) client ECDSA private key in PEM
+/* format.
+/* .IP "\fBtlsproxy_client_fingerprint_digest ($smtp_tls_fingerprint_digest)\fR"
+/* The message digest algorithm used to construct remote TLS server
+/* certificate fingerprints.
+/* .IP "\fBtlsproxy_client_loglevel ($smtp_tls_loglevel)\fR"
+/* Enable additional Postfix \fBtlsproxy\fR(8) client logging of TLS
+/* activity.
+/* .IP "\fBtlsproxy_client_loglevel_parameter (smtp_tls_loglevel)\fR"
+/* The name of the parameter that provides the tlsproxy_client_loglevel
+/* value.
+/* .IP "\fBtlsproxy_client_scert_verifydepth ($smtp_tls_scert_verifydepth)\fR"
+/* The verification depth for remote TLS server certificates.
+/* .IP "\fBtlsproxy_client_use_tls ($smtp_use_tls)\fR"
+/* Opportunistic mode: use TLS when a remote server announces TLS
+/* support.
+/* .IP "\fBtlsproxy_client_enforce_tls ($smtp_enforce_tls)\fR"
+/* Enforcement mode: require that SMTP servers use TLS encryption.
+/* .IP "\fBtlsproxy_client_per_site ($smtp_tls_per_site)\fR"
+/* Optional lookup tables with the Postfix \fBtlsproxy\fR(8) client TLS
+/* usage policy by next-hop destination and by remote TLS server
+/* hostname.
+/* .PP
+/* Available in Postfix version 3.4-3.6:
+/* .IP "\fBtlsproxy_client_level ($smtp_tls_security_level)\fR"
+/* The default TLS security level for the Postfix \fBtlsproxy\fR(8)
+/* client.
+/* .IP "\fBtlsproxy_client_policy ($smtp_tls_policy_maps)\fR"
+/* Optional lookup tables with the Postfix \fBtlsproxy\fR(8) client TLS
+/* security policy by next-hop destination.
+/* .PP
+/* Available in Postfix version 3.7 and later:
+/* .IP "\fBtlsproxy_client_security_level ($smtp_tls_security_level)\fR"
+/* The default TLS security level for the Postfix \fBtlsproxy\fR(8)
+/* client.
+/* .IP "\fBtlsproxy_client_policy_maps ($smtp_tls_policy_maps)\fR"
+/* Optional lookup tables with the Postfix \fBtlsproxy\fR(8) client TLS
+/* security policy by next-hop destination.
+/* OBSOLETE STARTTLS SUPPORT CONTROLS
+/* .ad
+/* .fi
+/* These parameters are supported for compatibility with
+/* \fBsmtpd\fR(8) legacy parameters.
+/* .IP "\fBtlsproxy_use_tls ($smtpd_use_tls)\fR"
+/* Opportunistic TLS: announce STARTTLS support to remote SMTP clients,
+/* but do not require that clients use TLS encryption.
+/* .IP "\fBtlsproxy_enforce_tls ($smtpd_enforce_tls)\fR"
+/* Mandatory TLS: announce STARTTLS support to remote SMTP clients, and
+/* require that clients use TLS encryption.
+/* .IP "\fBtlsproxy_client_use_tls ($smtp_use_tls)\fR"
+/* Opportunistic mode: use TLS when a remote server announces TLS
+/* support.
+/* .IP "\fBtlsproxy_client_enforce_tls ($smtp_enforce_tls)\fR"
+/* Enforcement mode: require that SMTP servers use TLS encryption.
+/* RESOURCE CONTROLS
+/* .ad
+/* .fi
+/* .IP "\fBtlsproxy_watchdog_timeout (10s)\fR"
+/* How much time a \fBtlsproxy\fR(8) process may take to process local
+/* or remote I/O before it is terminated by a built-in watchdog timer.
+/* MISCELLANEOUS CONTROLS
+/* .ad
+/* .fi
+/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
+/* The default location of the Postfix main.cf and master.cf
+/* configuration files.
+/* .IP "\fBprocess_id (read-only)\fR"
+/* The process ID of a Postfix command or daemon process.
+/* .IP "\fBprocess_name (read-only)\fR"
+/* The process name of a Postfix command or daemon process.
+/* .IP "\fBsyslog_facility (mail)\fR"
+/* The syslog facility of Postfix logging.
+/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
+/* A prefix that is prepended to the process name in syslog
+/* records, so that, for example, "smtpd" becomes "prefix/smtpd".
+/* .PP
+/* Available in Postfix 3.3 and later:
+/* .IP "\fBservice_name (read-only)\fR"
+/* The master.cf service name of a Postfix daemon process.
+/* SEE ALSO
+/* postscreen(8), Postfix zombie blocker
+/* smtpd(8), Postfix SMTP server
+/* postconf(5), configuration parameters
+/* postlogd(8), Postfix logging
+/* syslogd(8), system logging
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* HISTORY
+/* .ad
+/* .fi
+/* This service was introduced with Postfix version 2.8.
+/* 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 <errno.h>
+
+#ifdef STRCASECMP_IN_STRINGS_H
+#include <strings.h>
+#endif
+
+ /*
+ * Utility library.
+ */
+#include <msg.h>
+#include <vstream.h>
+#include <iostuff.h>
+#include <nbbio.h>
+#include <mymalloc.h>
+#include <split_at.h>
+
+ /*
+ * Global library.
+ */
+#include <been_here.h>
+#include <mail_proto.h>
+#include <mail_params.h>
+#include <mail_conf.h>
+#include <mail_version.h>
+
+ /*
+ * Master library.
+ */
+#include <mail_server.h>
+
+ /*
+ * TLS library.
+ */
+#ifdef USE_TLS
+#define TLS_INTERNAL /* XXX */
+#include <tls.h>
+#include <tls_proxy.h>
+
+ /*
+ * Application-specific.
+ */
+#include <tlsproxy.h>
+
+ /*
+ * Tunable parameters. We define our clones of the smtpd(8) parameters to
+ * avoid any confusion about which parameters are used by this program.
+ */
+int var_smtpd_tls_ccert_vd;
+char *var_smtpd_tls_loglevel;
+bool var_smtpd_use_tls;
+bool var_smtpd_enforce_tls;
+bool var_smtpd_tls_ask_ccert;
+bool var_smtpd_tls_req_ccert;
+bool var_smtpd_tls_set_sessid;
+char *var_smtpd_relay_ccerts;
+char *var_smtpd_tls_chain_files;
+char *var_smtpd_tls_cert_file;
+char *var_smtpd_tls_key_file;
+char *var_smtpd_tls_dcert_file;
+char *var_smtpd_tls_dkey_file;
+char *var_smtpd_tls_eccert_file;
+char *var_smtpd_tls_eckey_file;
+char *var_smtpd_tls_CAfile;
+char *var_smtpd_tls_CApath;
+char *var_smtpd_tls_ciph;
+char *var_smtpd_tls_mand_ciph;
+char *var_smtpd_tls_excl_ciph;
+char *var_smtpd_tls_mand_excl;
+char *var_smtpd_tls_proto;
+char *var_smtpd_tls_mand_proto;
+char *var_smtpd_tls_dh512_param_file;
+char *var_smtpd_tls_dh1024_param_file;
+char *var_smtpd_tls_eecdh;
+char *var_smtpd_tls_fpt_dgst;
+char *var_smtpd_tls_level;
+
+int var_tlsp_tls_ccert_vd;
+char *var_tlsp_tls_loglevel;
+bool var_tlsp_use_tls;
+bool var_tlsp_enforce_tls;
+bool var_tlsp_tls_ask_ccert;
+bool var_tlsp_tls_req_ccert;
+bool var_tlsp_tls_set_sessid;
+char *var_tlsp_tls_chain_files;
+char *var_tlsp_tls_cert_file;
+char *var_tlsp_tls_key_file;
+char *var_tlsp_tls_dcert_file;
+char *var_tlsp_tls_dkey_file;
+char *var_tlsp_tls_eccert_file;
+char *var_tlsp_tls_eckey_file;
+char *var_tlsp_tls_CAfile;
+char *var_tlsp_tls_CApath;
+char *var_tlsp_tls_ciph;
+char *var_tlsp_tls_mand_ciph;
+char *var_tlsp_tls_excl_ciph;
+char *var_tlsp_tls_mand_excl;
+char *var_tlsp_tls_proto;
+char *var_tlsp_tls_mand_proto;
+char *var_tlsp_tls_dh512_param_file;
+char *var_tlsp_tls_dh1024_param_file;
+char *var_tlsp_tls_eecdh;
+char *var_tlsp_tls_fpt_dgst;
+char *var_tlsp_tls_level;
+
+int var_tlsp_watchdog;
+
+ /*
+ * Defaults for tlsp_clnt_*.
+ */
+char *var_smtp_tls_loglevel;
+int var_smtp_tls_scert_vd;
+char *var_smtp_tls_chain_files;
+char *var_smtp_tls_cert_file;
+char *var_smtp_tls_key_file;
+char *var_smtp_tls_dcert_file;
+char *var_smtp_tls_dkey_file;
+char *var_smtp_tls_eccert_file;
+char *var_smtp_tls_eckey_file;
+char *var_smtp_tls_CAfile;
+char *var_smtp_tls_CApath;
+char *var_smtp_tls_fpt_dgst;
+char *var_smtp_tls_level;
+bool var_smtp_use_tls;
+bool var_smtp_enforce_tls;
+char *var_smtp_tls_per_site;
+char *var_smtp_tls_policy;
+
+char *var_tlsp_clnt_loglevel;
+char *var_tlsp_clnt_logparam;
+int var_tlsp_clnt_scert_vd;
+char *var_tlsp_clnt_chain_files;
+char *var_tlsp_clnt_cert_file;
+char *var_tlsp_clnt_key_file;
+char *var_tlsp_clnt_dcert_file;
+char *var_tlsp_clnt_dkey_file;
+char *var_tlsp_clnt_eccert_file;
+char *var_tlsp_clnt_eckey_file;
+char *var_tlsp_clnt_CAfile;
+char *var_tlsp_clnt_CApath;
+char *var_tlsp_clnt_fpt_dgst;
+char *var_tlsp_clnt_level;
+bool var_tlsp_clnt_use_tls;
+bool var_tlsp_clnt_enforce_tls;
+char *var_tlsp_clnt_per_site;
+char *var_tlsp_clnt_policy;
+
+ /*
+ * TLS per-process status.
+ */
+static TLS_APPL_STATE *tlsp_server_ctx;
+static bool tlsp_pre_jail_done;
+static int ask_client_cert;
+static char *tlsp_pre_jail_client_param_key; /* pre-jail global params */
+static char *tlsp_pre_jail_client_init_key; /* pre-jail init props */
+
+ /*
+ * TLS per-client status.
+ */
+static HTABLE *tlsp_client_app_cache; /* per-client init props */
+static BH_TABLE *tlsp_params_mismatch_filter; /* per-client nag filter */
+
+ /*
+ * Error handling: if a function detects an error, then that function is
+ * responsible for destroying TLSP_STATE. Exceptions to this principle are
+ * indicated in the code.
+ */
+
+ /*
+ * Internal status API.
+ */
+#define TLSP_STAT_OK 0
+#define TLSP_STAT_ERR (-1)
+
+ /*
+ * SLMs.
+ */
+#define STR(x) vstring_str(x)
+#define LEN(x) VSTRING_LEN(x)
+
+ /*
+ * The code that implements the TLS engine looks simpler than expected. That
+ * is the result of a great deal of effort, mainly in design and analysis.
+ *
+ * The initial use case was to provide TLS support for postscreen(8).
+ *
+ * By design, postscreen(8) is an event-driven server that must scale up to a
+ * large number of clients. This means that postscreen(8) must avoid doing
+ * CPU-intensive operations such as those in OpenSSL.
+ *
+ * tlsproxy(8) runs the OpenSSL code on behalf of postscreen(8), translating
+ * plaintext SMTP messages from postscreen(8) into SMTP-over-TLS messages to
+ * the remote SMTP client, and vice versa. As long as postscreen(8) does not
+ * receive email messages, the cost of doing TLS operations will be modest.
+ *
+ * Like postscreen(8), one tlsproxy(8) process services multiple remote SMTP
+ * clients. Unlike postscreen(8), there can be more than one tlsproxy(8)
+ * process, although their number is meant to be much smaller than the
+ * number of remote SMTP clients that talk TLS.
+ *
+ * As with postscreen(8), all I/O must be event-driven: encrypted traffic
+ * between tlsproxy(8) and remote SMTP clients, and plaintext traffic
+ * between tlsproxy(8) and postscreen(8). Event-driven plaintext I/O is
+ * straightforward enough that it could be abstracted away with the nbbio(3)
+ * module.
+ *
+ * The event-driven TLS I/O implementation is founded on on-line OpenSSL
+ * documentation, supplemented by statements from OpenSSL developers on
+ * public mailing lists. After some field experience with this code, we may
+ * be able to factor it out as a library module, like nbbio(3), that can
+ * become part of the TLS library.
+ *
+ * Later in the life cycle, tlsproxy(8) has also become an enabler for TLS
+ * connection reuse across different SMTP client processes.
+ */
+
+static void tlsp_ciphertext_event(int, void *);
+
+#define TLSP_INIT_TIMEOUT 100
+
+static void tlsp_plaintext_event(int event, void *context);
+
+/* tlsp_drain - delayed exit after "postfix reload" */
+
+static void tlsp_drain(char *unused_service, char **unused_argv)
+{
+ int count;
+
+ /*
+ * After "postfix reload", complete work-in-progress in the background,
+ * instead of dropping already-accepted connections on the floor.
+ *
+ * All error retry counts shall be limited. Instead of blocking here, we
+ * could retry failed fork() operations in the event call-back routines,
+ * but we don't need perfection. The host system is severely overloaded
+ * and service levels are already way down.
+ */
+ for (count = 0; /* see below */ ; count++) {
+ if (count >= 5) {
+ msg_fatal("fork: %m");
+ } else if (event_server_drain() != 0) {
+ msg_warn("fork: %m");
+ sleep(1);
+ continue;
+ } else {
+ return;
+ }
+ }
+}
+
+/* tlsp_eval_tls_error - translate TLS "error" result into action */
+
+static int tlsp_eval_tls_error(TLSP_STATE *state, int err)
+{
+ int ciphertext_fd = state->ciphertext_fd;
+
+ /*
+ * The ciphertext file descriptor is in non-blocking mode, meaning that
+ * each SSL_accept/connect/read/write/shutdown request may return an
+ * "error" indication that it needs to read or write more ciphertext. The
+ * purpose of this routine is to translate those "error" indications into
+ * the appropriate read/write/timeout event requests.
+ */
+ switch (err) {
+
+ /*
+ * No error means a successful SSL_accept/connect/shutdown request or
+ * sequence of SSL_read/write requests. Disable read/write events on
+ * the ciphertext stream. Keep the ciphertext stream timer alive as a
+ * safety mechanism for the case that the plaintext pseudothreads get
+ * stuck.
+ */
+ case SSL_ERROR_NONE:
+ if (state->ssl_last_err != SSL_ERROR_NONE) {
+ event_disable_readwrite(ciphertext_fd);
+ event_request_timer(tlsp_ciphertext_event, (void *) state,
+ state->timeout);
+ state->ssl_last_err = SSL_ERROR_NONE;
+ }
+ return (TLSP_STAT_OK);
+
+ /*
+ * The TLS engine wants to write to the network. Turn on
+ * write/timeout events on the ciphertext stream.
+ */
+ case SSL_ERROR_WANT_WRITE:
+ if (state->ssl_last_err == SSL_ERROR_WANT_READ)
+ event_disable_readwrite(ciphertext_fd);
+ if (state->ssl_last_err != SSL_ERROR_WANT_WRITE) {
+ event_enable_write(ciphertext_fd, tlsp_ciphertext_event,
+ (void *) state);
+ state->ssl_last_err = SSL_ERROR_WANT_WRITE;
+ }
+ event_request_timer(tlsp_ciphertext_event, (void *) state,
+ state->timeout);
+ return (TLSP_STAT_OK);
+
+ /*
+ * The TLS engine wants to read from the network. Turn on
+ * read/timeout events on the ciphertext stream.
+ */
+ case SSL_ERROR_WANT_READ:
+ if (state->ssl_last_err == SSL_ERROR_WANT_WRITE)
+ event_disable_readwrite(ciphertext_fd);
+ if (state->ssl_last_err != SSL_ERROR_WANT_READ) {
+ event_enable_read(ciphertext_fd, tlsp_ciphertext_event,
+ (void *) state);
+ state->ssl_last_err = SSL_ERROR_WANT_READ;
+ }
+ event_request_timer(tlsp_ciphertext_event, (void *) state,
+ state->timeout);
+ return (TLSP_STAT_OK);
+
+ /*
+ * Some error. Self-destruct. This automagically cleans up all
+ * pending read/write and timeout event requests, making state a
+ * dangling pointer.
+ */
+ case SSL_ERROR_SSL:
+ tls_print_errors();
+ /* FALLTHROUGH */
+ default:
+
+ /*
+ * Allow buffered-up plaintext output to trickle out. Permanently
+ * disable read/write activity on the ciphertext stream, so that this
+ * function will no longer be called. Keep the ciphertext stream
+ * timer alive as a safety mechanism for the case that the plaintext
+ * pseudothreads get stuck. Return into tlsp_strategy(), which will
+ * enable plaintext write events.
+ */
+#define TLSP_CAN_TRICKLE_OUT_PLAINTEXT(buf) \
+ ((buf) && !NBBIO_ERROR_FLAGS(buf) && NBBIO_WRITE_PEND(buf))
+
+ if (TLSP_CAN_TRICKLE_OUT_PLAINTEXT(state->plaintext_buf)) {
+ event_disable_readwrite(ciphertext_fd);
+ event_request_timer(tlsp_ciphertext_event, (void *) state,
+ state->timeout);
+ state->flags |= TLSP_FLAG_NO_MORE_CIPHERTEXT_IO;
+ return (TLSP_STAT_OK);
+ }
+ tlsp_state_free(state);
+ return (TLSP_STAT_ERR);
+ }
+}
+
+/* tlsp_post_handshake - post-handshake processing */
+
+static int tlsp_post_handshake(TLSP_STATE *state)
+{
+
+ /*
+ * Do not assume that tls_server_post_accept() and
+ * tls_client_post_connect() will always succeed.
+ */
+ if (state->is_server_role)
+ state->tls_context = tls_server_post_accept(state->tls_context);
+ else
+ state->tls_context = tls_client_post_connect(state->tls_context,
+ state->client_start_props);
+ if (state->tls_context == 0) {
+ tlsp_state_free(state);
+ return (TLSP_STAT_ERR);
+ }
+
+ /*
+ * Report TLS handshake results to the tlsproxy client.
+ *
+ * Security: this sends internal data over the same local plaintext stream
+ * that will also be used for sending decrypted remote content from an
+ * arbitrary remote peer. For this reason we enable decrypted I/O only
+ * after reporting the TLS handshake results. The Postfix attribute
+ * protocol is robust enough that an attacker cannot append content.
+ */
+ if ((state->req_flags & TLS_PROXY_FLAG_SEND_CONTEXT) != 0
+ && (attr_print(state->plaintext_stream, ATTR_FLAG_NONE,
+ SEND_ATTR_FUNC(tls_proxy_context_print,
+ (void *) state->tls_context),
+ ATTR_TYPE_END) != 0
+ || vstream_fflush(state->plaintext_stream) != 0)) {
+ msg_warn("cannot send TLS context: %m");
+ tlsp_state_free(state);
+ return (TLSP_STAT_ERR);
+ }
+
+ /*
+ * Initialize plaintext-related session state. Once we have this behind
+ * us, the TLSP_STATE destructor will automagically clean up requests for
+ * plaintext read/write/timeout events, which makes error recovery
+ * easier.
+ */
+ state->plaintext_buf =
+ nbbio_create(vstream_fileno(state->plaintext_stream),
+ VSTREAM_BUFSIZE, state->server_id,
+ tlsp_plaintext_event,
+ (void *) state);
+ return (TLSP_STAT_OK);
+}
+
+/* tlsp_strategy - decide what to read or write next. */
+
+static void tlsp_strategy(TLSP_STATE *state)
+{
+ TLS_SESS_STATE *tls_context = state->tls_context;
+ NBBIO *plaintext_buf;
+ int ssl_stat;
+ int ssl_read_err;
+ int ssl_write_err;
+ int handshake_err;
+
+ /*
+ * This function is called after every ciphertext or plaintext event, to
+ * schedule new ciphertext or plaintext I/O.
+ */
+
+ /*
+ * Try to make an SSL I/O request. If this fails with SSL_ERROR_WANT_READ
+ * or SSL_ERROR_WANT_WRITE, enable ciphertext read or write events, and
+ * retry the SSL I/O request in a later tlsp_strategy() call.
+ */
+ if ((state->flags & TLSP_FLAG_NO_MORE_CIPHERTEXT_IO) == 0) {
+
+ /*
+ * Do not enable plain-text I/O before completing the TLS handshake.
+ * Otherwise the remote peer can prepend plaintext to the optional
+ * TLS_SESS_STATE object.
+ */
+ if (state->flags & TLSP_FLAG_DO_HANDSHAKE) {
+ state->timeout = state->handshake_timeout;
+ ERR_clear_error();
+ if (state->is_server_role)
+ ssl_stat = SSL_accept(tls_context->con);
+ else
+ ssl_stat = SSL_connect(tls_context->con);
+ if (ssl_stat != 1) {
+ handshake_err = SSL_get_error(tls_context->con, ssl_stat);
+ tlsp_eval_tls_error(state, handshake_err);
+ /* At this point, state could be a dangling pointer. */
+ return;
+ }
+ state->flags &= ~TLSP_FLAG_DO_HANDSHAKE;
+ state->timeout = state->session_timeout;
+ if (tlsp_post_handshake(state) != TLSP_STAT_OK) {
+ /* At this point, state is a dangling pointer. */
+ return;
+ }
+ }
+
+ /*
+ * Shutdown and self-destruct after NBBIO error. This automagically
+ * cleans up all pending read/write and timeout event requests.
+ * Before shutting down TLS, we stop all plain-text I/O events but
+ * keep the NBBIO error flags.
+ */
+ plaintext_buf = state->plaintext_buf;
+ if (NBBIO_ERROR_FLAGS(plaintext_buf)) {
+ if (NBBIO_ACTIVE_FLAGS(plaintext_buf))
+ nbbio_disable_readwrite(state->plaintext_buf);
+ ERR_clear_error();
+ if (!SSL_in_init(tls_context->con)
+ && (ssl_stat = SSL_shutdown(tls_context->con)) < 0) {
+ handshake_err = SSL_get_error(tls_context->con, ssl_stat);
+ tlsp_eval_tls_error(state, handshake_err);
+ /* At this point, state could be a dangling pointer. */
+ return;
+ }
+ tlsp_state_free(state);
+ return;
+ }
+
+ /*
+ * Try to move data from the plaintext input buffer to the TLS
+ * engine.
+ *
+ * XXX We're supposed to repeat the exact same SSL_write() call
+ * arguments after an SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE
+ * result. Rumor has it that this is because each SSL_write() call
+ * reads from the buffer incrementally, and returns > 0 only after
+ * the final byte is processed. Rumor also has it that setting
+ * SSL_MODE_ENABLE_PARTIAL_WRITE and
+ * SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER voids this requirement, and
+ * that repeating the request with an increased request size is OK.
+ * Unfortunately all this is not or poorly documented, and one has to
+ * rely on statements from OpenSSL developers in public mailing
+ * archives.
+ */
+ ssl_write_err = SSL_ERROR_NONE;
+ while (NBBIO_READ_PEND(plaintext_buf) > 0) {
+ ERR_clear_error();
+ ssl_stat = SSL_write(tls_context->con, NBBIO_READ_BUF(plaintext_buf),
+ NBBIO_READ_PEND(plaintext_buf));
+ ssl_write_err = SSL_get_error(tls_context->con, ssl_stat);
+ if (ssl_write_err != SSL_ERROR_NONE)
+ break;
+ /* Allow the plaintext pseudothread to read more data. */
+ NBBIO_READ_PEND(plaintext_buf) -= ssl_stat;
+ if (NBBIO_READ_PEND(plaintext_buf) > 0)
+ memmove(NBBIO_READ_BUF(plaintext_buf),
+ NBBIO_READ_BUF(plaintext_buf) + ssl_stat,
+ NBBIO_READ_PEND(plaintext_buf));
+ }
+
+ /*
+ * Try to move data from the TLS engine to the plaintext output
+ * buffer. Note: data may arrive as a side effect of calling
+ * SSL_write(), therefore we call SSL_read() after calling
+ * SSL_write().
+ *
+ * XXX We're supposed to repeat the exact same SSL_read() call arguments
+ * after an SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE result. This
+ * supposedly means that our plaintext writer must not memmove() the
+ * plaintext output buffer until after the SSL_read() call succeeds.
+ * For now I'll ignore this, because 1) SSL_read() is documented to
+ * return the bytes available, instead of returning > 0 only after
+ * the entire buffer is processed like SSL_write() does; and 2) there
+ * is no "read" equivalent of the SSL_R_BAD_WRITE_RETRY,
+ * SSL_MODE_ENABLE_PARTIAL_WRITE or
+ * SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER features.
+ */
+ ssl_read_err = SSL_ERROR_NONE;
+ while (NBBIO_WRITE_PEND(state->plaintext_buf) < NBBIO_BUFSIZE(plaintext_buf)) {
+ ERR_clear_error();
+ ssl_stat = SSL_read(tls_context->con,
+ NBBIO_WRITE_BUF(plaintext_buf)
+ + NBBIO_WRITE_PEND(state->plaintext_buf),
+ NBBIO_BUFSIZE(plaintext_buf)
+ - NBBIO_WRITE_PEND(state->plaintext_buf));
+ ssl_read_err = SSL_get_error(tls_context->con, ssl_stat);
+ if (ssl_read_err != SSL_ERROR_NONE)
+ break;
+ NBBIO_WRITE_PEND(plaintext_buf) += ssl_stat;
+ }
+
+ /*
+ * Try to enable/disable ciphertext read/write events. If SSL_write()
+ * was satisfied, see if SSL_read() wants to do some work. In case of
+ * an unrecoverable error, this automagically destroys the session
+ * state after cleaning up all pending read/write and timeout event
+ * requests.
+ */
+ if (tlsp_eval_tls_error(state, ssl_write_err != SSL_ERROR_NONE ?
+ ssl_write_err : ssl_read_err) < 0)
+ /* At this point, state is a dangling pointer. */
+ return;
+ }
+
+ /*
+ * Destroy state when the ciphertext I/O was permanently disabled and we
+ * can no longer trickle out plaintext.
+ */
+ else {
+ plaintext_buf = state->plaintext_buf;
+ if (!TLSP_CAN_TRICKLE_OUT_PLAINTEXT(plaintext_buf)) {
+ tlsp_state_free(state);
+ return;
+ }
+ }
+
+ /*
+ * Try to enable/disable plaintext read/write events. Basically, if we
+ * have nothing to write to the plaintext stream, see if there is
+ * something to read. If the write buffer is empty and the read buffer is
+ * full, suspend plaintext I/O until conditions change (but keep the
+ * timer active, as a safety mechanism in case ciphertext I/O gets
+ * stuck).
+ *
+ * XXX In theory, if the ciphertext peer keeps writing fast enough then we
+ * would never read from the plaintext stream and cause the latter to
+ * block. In practice, postscreen(8) limits the number of client
+ * commands, and thus postscreen(8)'s output will fit in a kernel buffer.
+ * A remote SMTP server is not supposed to flood the local SMTP client
+ * with massive replies; if it does, then the local SMTP client should
+ * deal with it.
+ */
+ if (NBBIO_WRITE_PEND(plaintext_buf) > 0) {
+ if (NBBIO_ACTIVE_FLAGS(plaintext_buf) & NBBIO_FLAG_READ)
+ nbbio_disable_readwrite(plaintext_buf);
+ nbbio_enable_write(plaintext_buf, state->timeout);
+ } else if (NBBIO_READ_PEND(plaintext_buf) < NBBIO_BUFSIZE(plaintext_buf)) {
+ if (NBBIO_ACTIVE_FLAGS(plaintext_buf) & NBBIO_FLAG_WRITE)
+ nbbio_disable_readwrite(plaintext_buf);
+ nbbio_enable_read(plaintext_buf, state->timeout);
+ } else {
+ if (NBBIO_ACTIVE_FLAGS(plaintext_buf))
+ nbbio_slumber(plaintext_buf, state->timeout);
+ }
+}
+
+/* tlsp_plaintext_event - plaintext was read/written */
+
+static void tlsp_plaintext_event(int event, void *context)
+{
+ TLSP_STATE *state = (TLSP_STATE *) context;
+
+ /*
+ * Safety alert: the plaintext pseudothreads have "slumbered" for too
+ * long (see code above). This means that the ciphertext pseudothreads
+ * are stuck.
+ */
+ if ((NBBIO_ERROR_FLAGS(state->plaintext_buf) & NBBIO_FLAG_TIMEOUT) != 0
+ && NBBIO_ACTIVE_FLAGS(state->plaintext_buf) == 0)
+ msg_warn("deadlock on ciphertext stream for %s", state->remote_endpt);
+
+ /*
+ * This is easy, because the NBBIO layer has already done the event
+ * decoding and plaintext I/O for us. All we need to do is decide if we
+ * want to read or write more plaintext.
+ */
+ tlsp_strategy(state);
+ /* At this point, state could be a dangling pointer. */
+}
+
+/* tlsp_ciphertext_event - ciphertext is ready to read/write */
+
+static void tlsp_ciphertext_event(int event, void *context)
+{
+ TLSP_STATE *state = (TLSP_STATE *) context;
+
+ /*
+ * Without a TLS equivalent of the NBBIO layer, we must decode the events
+ * ourselves and do the ciphertext I/O. Then, we can decide if we want to
+ * read or write more ciphertext.
+ */
+ if (event == EVENT_READ || event == EVENT_WRITE) {
+ tlsp_strategy(state);
+ /* At this point, state could be a dangling pointer. */
+ } else {
+ if (event == EVENT_TIME && state->ssl_last_err == SSL_ERROR_NONE)
+ msg_warn("deadlock on plaintext stream for %s",
+ state->remote_endpt);
+ else
+ msg_warn("ciphertext read/write %s for %s",
+ event == EVENT_TIME ? "timeout" : "error",
+ state->remote_endpt);
+ tlsp_state_free(state);
+ }
+}
+
+/* tlsp_client_start_pre_handshake - turn on TLS or force disconnect */
+
+static int tlsp_client_start_pre_handshake(TLSP_STATE *state)
+{
+ state->client_start_props->ctx = state->appl_state;
+ state->client_start_props->fd = state->ciphertext_fd;
+ state->tls_context = tls_client_start(state->client_start_props);
+ if (state->tls_context != 0)
+ return (TLSP_STAT_OK);
+
+ tlsp_state_free(state);
+ return (TLSP_STAT_ERR);
+}
+
+/* tlsp_server_start_pre_handshake - turn on TLS or force disconnect */
+
+static int tlsp_server_start_pre_handshake(TLSP_STATE *state)
+{
+ TLS_SERVER_START_PROPS props;
+ static char *cipher_grade;
+ static VSTRING *cipher_exclusions;
+
+ /*
+ * The code in this routine is pasted literally from smtpd(8). I am not
+ * going to sanitize this because doing so surely will break things in
+ * unexpected ways.
+ */
+
+ /*
+ * Perform the before-handshake portion of per-session initialization.
+ * Pass a null VSTREAM to indicate that this program will do the
+ * ciphertext I/O, not libtls.
+ *
+ * The cipher grade and exclusions don't change between sessions. Compute
+ * just once and cache.
+ */
+#define ADD_EXCLUDE(vstr, str) \
+ do { \
+ if (*(str)) \
+ vstring_sprintf_append((vstr), "%s%s", \
+ VSTRING_LEN(vstr) ? " " : "", (str)); \
+ } while (0)
+
+ if (cipher_grade == 0) {
+ cipher_grade =
+ var_tlsp_enforce_tls ? var_tlsp_tls_mand_ciph : var_tlsp_tls_ciph;
+ cipher_exclusions = vstring_alloc(10);
+ ADD_EXCLUDE(cipher_exclusions, var_tlsp_tls_excl_ciph);
+ if (var_tlsp_enforce_tls)
+ ADD_EXCLUDE(cipher_exclusions, var_tlsp_tls_mand_excl);
+ if (ask_client_cert)
+ ADD_EXCLUDE(cipher_exclusions, "aNULL");
+ }
+ state->tls_context =
+ TLS_SERVER_START(&props,
+ ctx = tlsp_server_ctx,
+ stream = (VSTREAM *) 0,/* unused */
+ fd = state->ciphertext_fd,
+ timeout = 0, /* unused */
+ requirecert = (var_tlsp_tls_req_ccert
+ && var_tlsp_enforce_tls),
+ serverid = state->server_id,
+ namaddr = state->remote_endpt,
+ cipher_grade = cipher_grade,
+ cipher_exclusions = STR(cipher_exclusions),
+ mdalg = var_tlsp_tls_fpt_dgst);
+
+ if (state->tls_context == 0) {
+ tlsp_state_free(state);
+ return (TLSP_STAT_ERR);
+ }
+
+ /*
+ * XXX Do we care about TLS session rate limits? Good postscreen(8)
+ * clients will occasionally require the tlsproxy to renew their
+ * allowlist status, but bad clients hammering the server can suck up
+ * lots of CPU cycles. Per-client concurrency limits in postscreen(8)
+ * will divert only naive security "researchers".
+ */
+ return (TLSP_STAT_OK);
+}
+
+ /*
+ * From here on down is low-level code that sets up the plumbing before
+ * passing control to the TLS engine above.
+ */
+
+/* tlsp_request_read_event - pre-handshake event boiler plate */
+
+static void tlsp_request_read_event(int fd, EVENT_NOTIFY_FN handler,
+ int timeout, void *context)
+{
+ event_enable_read(fd, handler, context);
+ event_request_timer(handler, context, timeout);
+}
+
+/* tlsp_accept_event - pre-handshake event boiler plate */
+
+static void tlsp_accept_event(int event, EVENT_NOTIFY_FN handler,
+ void *context)
+{
+ if (event != EVENT_TIME)
+ event_cancel_timer(handler, context);
+ else
+ errno = ETIMEDOUT;
+ /* tlsp_state_free() disables pre-handshake plaintext I/O events. */
+}
+
+/* tlsp_get_fd_event - receive final connection hand-off information */
+
+static void tlsp_get_fd_event(int event, void *context)
+{
+ const char *myname = "tlsp_get_fd_event";
+ TLSP_STATE *state = (TLSP_STATE *) context;
+ int plaintext_fd = vstream_fileno(state->plaintext_stream);
+ int status;
+
+ /*
+ * At this point we still manually manage plaintext read/write/timeout
+ * events. Disable I/O events on the plaintext stream until the TLS
+ * handshake is completed. Every code path must either destroy state, or
+ * request the next event, otherwise we have a file and memory leak.
+ */
+ tlsp_accept_event(event, tlsp_get_fd_event, (void *) state);
+ event_disable_readwrite(plaintext_fd);
+
+ if (event != EVENT_READ
+ || (state->ciphertext_fd = LOCAL_RECV_FD(plaintext_fd)) < 0) {
+ msg_warn("%s: receive remote SMTP peer file descriptor: %m", myname);
+ tlsp_state_free(state);
+ return;
+ }
+
+ /*
+ * This is a bit early, to ensure that timer events for this file handle
+ * are guaranteed to be turned off by the TLSP_STATE destructor.
+ */
+ state->ciphertext_timer = tlsp_ciphertext_event;
+ non_blocking(state->ciphertext_fd, NON_BLOCKING);
+
+ /*
+ * Perform the TLS layer before-handshake initialization. We perform the
+ * remainder after the actual TLS handshake completes.
+ */
+ if (state->is_server_role)
+ status = tlsp_server_start_pre_handshake(state);
+ else
+ status = tlsp_client_start_pre_handshake(state);
+ if (status != TLSP_STAT_OK)
+ /* At this point, state is a dangling pointer. */
+ return;
+
+ /*
+ * Trigger the initial proxy server I/Os.
+ */
+ tlsp_strategy(state);
+ /* At this point, state could be a dangling pointer. */
+}
+
+/* tlsp_config_diff - report server-client config differences */
+
+static void tlsp_log_config_diff(const char *server_cfg, const char *client_cfg)
+{
+ VSTRING *diff_summary = vstring_alloc(100);
+ char *saved_server = mystrdup(server_cfg);
+ char *saved_client = mystrdup(client_cfg);
+ char *server_field;
+ char *client_field;
+ char *server_next;
+ char *client_next;
+
+ /*
+ * Not using argv_split(), because it would treat multiple consecutive
+ * newline characters as one.
+ */
+ for (server_field = saved_server, client_field = saved_client;
+ server_field && client_field;
+ server_field = server_next, client_field = client_next) {
+ server_next = split_at(server_field, '\n');
+ client_next = split_at(client_field, '\n');
+ if (strcmp(server_field, client_field) != 0) {
+ if (LEN(diff_summary) > 0)
+ vstring_sprintf_append(diff_summary, "; ");
+ vstring_sprintf_append(diff_summary,
+ "(server) '%s' != (client) '%s'",
+ server_field, client_field);
+ }
+ }
+ msg_warn("%s", STR(diff_summary));
+
+ vstring_free(diff_summary);
+ myfree(saved_client);
+ myfree(saved_server);
+}
+
+/* tlsp_client_init - initialize a TLS client engine */
+
+static TLS_APPL_STATE *tlsp_client_init(TLS_CLIENT_PARAMS *tls_params,
+ TLS_CLIENT_INIT_PROPS *init_props)
+{
+ TLS_APPL_STATE *appl_state;
+ VSTRING *param_buf;
+ char *param_key;
+ VSTRING *init_buf;
+ char *init_key;
+ int log_hints = 0;
+
+ /*
+ * Use one TLS_APPL_STATE object for all requests that specify the same
+ * TLS_CLIENT_INIT_PROPS. Each TLS_APPL_STATE owns an SSL_CTX, which is
+ * expensive to create. Bug: TLS_CLIENT_PARAMS are not used when creating
+ * a TLS_APPL_STATE instance.
+ *
+ * First, compute the TLS_APPL_STATE cache lookup key. Save a copy of the
+ * pre-jail request TLS_CLIENT_PARAMS and TLSPROXY_CLIENT_INIT_PROPS
+ * settings, so that we can detect post-jail requests that do not match.
+ */
+ param_buf = vstring_alloc(100);
+ param_key = tls_proxy_client_param_serialize(attr_print_plain, param_buf,
+ tls_params);
+ init_buf = vstring_alloc(100);
+ init_key = tls_proxy_client_init_serialize(attr_print_plain, init_buf,
+ init_props);
+ if (tlsp_pre_jail_done == 0) {
+ if (tlsp_pre_jail_client_param_key == 0
+ || tlsp_pre_jail_client_init_key == 0) {
+ tlsp_pre_jail_client_param_key = mystrdup(param_key);
+ tlsp_pre_jail_client_init_key = mystrdup(init_key);
+ } else if (strcmp(tlsp_pre_jail_client_param_key, param_key) != 0
+ || strcmp(tlsp_pre_jail_client_init_key, init_key) != 0) {
+ msg_panic("tlsp_client_init: too many pre-jail calls");
+ }
+ }
+
+ /*
+ * Log a warning if a post-jail request uses unexpected TLS_CLIENT_PARAMS
+ * settings. Bug: TLS_CLIENT_PARAMS settings are not used when creating a
+ * TLS_APPL_STATE instance; this makes a mismatch of TLS_CLIENT_PARAMS
+ * settings problematic.
+ */
+ if (tlsp_pre_jail_done
+ && !been_here_fixed(tlsp_params_mismatch_filter, param_key)
+ && strcmp(tlsp_pre_jail_client_param_key, param_key) != 0) {
+ msg_warn("request from tlsproxy client with unexpected settings");
+ tlsp_log_config_diff(tlsp_pre_jail_client_param_key, param_key);
+ log_hints = 1;
+ }
+
+ /*
+ * Look up the cached TLS_APPL_STATE for this tls_client_init request.
+ */
+ if ((appl_state = (TLS_APPL_STATE *)
+ htable_find(tlsp_client_app_cache, init_key)) == 0) {
+
+ /*
+ * Before creating a TLS_APPL_STATE instance, log a warning if a
+ * post-jail request differs from the saved pre-jail request AND the
+ * post-jail request specifies file/directory pathname arguments.
+ * Unexpected requests containing pathnames are problematic after
+ * chroot (pathname resolution) and after dropping privileges (key
+ * files must be root read-only). Unexpected requests are not a
+ * problem as long as they contain no pathnames (for example a
+ * tls_loglevel change).
+ *
+ * We could eliminate some of this complication by adding code that
+ * opens a cert/key lookup table at pre-jail time, and by reading
+ * cert/key info on-the-fly from that table. But then all requests
+ * would still have to specify the same table.
+ */
+#define NOT_EMPTY(x) ((x) && *(x))
+
+ if (tlsp_pre_jail_done
+ && strcmp(tlsp_pre_jail_client_init_key, init_key) != 0
+ && (NOT_EMPTY(init_props->chain_files)
+ || NOT_EMPTY(init_props->cert_file)
+ || NOT_EMPTY(init_props->key_file)
+ || NOT_EMPTY(init_props->dcert_file)
+ || NOT_EMPTY(init_props->dkey_file)
+ || NOT_EMPTY(init_props->eccert_file)
+ || NOT_EMPTY(init_props->eckey_file)
+ || NOT_EMPTY(init_props->CAfile)
+ || NOT_EMPTY(init_props->CApath))) {
+ msg_warn("request from tlsproxy client with unexpected settings");
+ tlsp_log_config_diff(tlsp_pre_jail_client_init_key, init_key);
+ log_hints = 1;
+ }
+ }
+ if (log_hints)
+ msg_warn("to avoid this warning, 1) identify the tlsproxy "
+ "client that is making this request, 2) configure "
+ "a custom tlsproxy service with settings that "
+ "match that tlsproxy client, and 3) configure "
+ "that tlsproxy client with a tlsproxy_service_name "
+ "setting that resolves to that custom tlsproxy "
+ "service");
+
+ /*
+ * TLS_APPL_STATE creation may fail when a post-jail request specifies
+ * unexpected cert/key information, but that is OK because we already
+ * logged a warning with configuration suggestions.
+ */
+ if (appl_state == 0
+ && (appl_state = tls_client_init(init_props)) != 0) {
+ (void) htable_enter(tlsp_client_app_cache, init_key,
+ (void *) appl_state);
+
+ /*
+ * To maintain sanity, allow partial SSL_write() operations, and
+ * allow SSL_write() buffer pointers to change after a WANT_READ or
+ * WANT_WRITE result. This is based on OpenSSL developers talking on
+ * a mailing list, but is not supported by documentation. If this
+ * code stops working then no-one can be held responsible.
+ */
+ SSL_CTX_set_mode(appl_state->ssl_ctx,
+ SSL_MODE_ENABLE_PARTIAL_WRITE
+ | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
+ }
+ vstring_free(init_buf);
+ vstring_free(param_buf);
+ return (appl_state);
+}
+
+/* tlsp_close_event - pre-handshake plaintext-client close event */
+
+static void tlsp_close_event(int event, void *context)
+{
+ TLSP_STATE *state = (TLSP_STATE *) context;
+
+ tlsp_accept_event(event, tlsp_close_event, (void *) state);
+ tlsp_state_free(state);
+}
+
+/* tlsp_get_request_event - receive initial hand-off info */
+
+static void tlsp_get_request_event(int event, void *context)
+{
+ const char *myname = "tlsp_get_request_event";
+ TLSP_STATE *state = (TLSP_STATE *) context;
+ VSTREAM *plaintext_stream = state->plaintext_stream;
+ int plaintext_fd = vstream_fileno(plaintext_stream);
+ static VSTRING *remote_endpt;
+ static VSTRING *server_id;
+ int req_flags;
+ int handshake_timeout;
+ int session_timeout;
+ int ready = 0;
+
+ /*
+ * At this point we still manually manage plaintext read/write/timeout
+ * events. Every code path must either destroy state or request the next
+ * event, otherwise this pseudo-thread is idle until the client goes
+ * away.
+ */
+ tlsp_accept_event(event, tlsp_get_request_event, (void *) state);
+
+ /*
+ * One-time initialization.
+ */
+ if (remote_endpt == 0) {
+ remote_endpt = vstring_alloc(10);
+ server_id = vstring_alloc(10);
+ }
+
+ /*
+ * Receive the initial request attributes. Receive the remainder after we
+ * figure out what role we are expected to play.
+ *
+ * The tlsproxy server does not enforce per-request read/write deadlines or
+ * minimal data rates. Instead, the tlsproxy server relies on the
+ * tlsproxy client to enforce these context-dependent limits. When a
+ * tlsproxy client decides to time out, it will close its end of the
+ * tlsproxy stream, and the tlsproxy server will handle that immediately.
+ */
+ if (event != EVENT_READ
+ || attr_scan(plaintext_stream, ATTR_FLAG_STRICT,
+ RECV_ATTR_STR(TLS_ATTR_REMOTE_ENDPT, remote_endpt),
+ RECV_ATTR_INT(TLS_ATTR_FLAGS, &req_flags),
+ RECV_ATTR_INT(TLS_ATTR_TIMEOUT, &handshake_timeout),
+ RECV_ATTR_INT(TLS_ATTR_TIMEOUT, &session_timeout),
+ RECV_ATTR_STR(TLS_ATTR_SERVERID, server_id),
+ ATTR_TYPE_END) != 5) {
+ msg_warn("%s: receive request attributes: %m", myname);
+ tlsp_state_free(state);
+ return;
+ }
+
+ /*
+ * XXX We use the same fixed timeout throughout the entire session for
+ * both plaintext and ciphertext communication. This timeout is just a
+ * safety feature; the real timeout will be enforced by our plaintext
+ * peer (except during TLS the handshake, when we intentionally disable
+ * plaintext I/O).
+ */
+ state->remote_endpt = mystrdup(STR(remote_endpt));
+ state->server_id = mystrdup(STR(server_id));
+ msg_info("CONNECT %s %s",
+ (req_flags & TLS_PROXY_FLAG_ROLE_SERVER) ? "from" :
+ (req_flags & TLS_PROXY_FLAG_ROLE_CLIENT) ? "to" :
+ "(bogus_direction)", state->remote_endpt);
+ state->req_flags = req_flags;
+ /* state->is_server_role is set below. */
+ state->handshake_timeout = handshake_timeout;
+ state->session_timeout = session_timeout + 10; /* XXX */
+
+ /*
+ * Receive the TLS preferences now, to reduce the number of protocol
+ * roundtrips.
+ */
+ switch (req_flags & (TLS_PROXY_FLAG_ROLE_CLIENT | TLS_PROXY_FLAG_ROLE_SERVER)) {
+ case TLS_PROXY_FLAG_ROLE_CLIENT:
+ state->is_server_role = 0;
+ if (attr_scan(plaintext_stream, ATTR_FLAG_STRICT,
+ RECV_ATTR_FUNC(tls_proxy_client_param_scan,
+ (void *) &state->tls_params),
+ RECV_ATTR_FUNC(tls_proxy_client_init_scan,
+ (void *) &state->client_init_props),
+ RECV_ATTR_FUNC(tls_proxy_client_start_scan,
+ (void *) &state->client_start_props),
+ ATTR_TYPE_END) != 3) {
+ msg_warn("%s: receive client TLS settings: %m", myname);
+ tlsp_state_free(state);
+ return;
+ }
+ state->appl_state = tlsp_client_init(state->tls_params,
+ state->client_init_props);
+ ready = state->appl_state != 0;
+ break;
+ case TLS_PROXY_FLAG_ROLE_SERVER:
+ state->is_server_role = 1;
+ ready = (tlsp_server_ctx != 0);
+ break;
+ default:
+ state->is_server_role = 0;
+ msg_warn("%s: bad request flags: 0x%x", myname, req_flags);
+ ready = 0;
+ }
+
+ /*
+ * For portability we must send some data, after receiving the request
+ * attributes and before receiving the remote file descriptor.
+ *
+ * If the requested TLS engine is unavailable, hang up after making sure
+ * that the plaintext peer has received our "sorry" indication.
+ */
+ if (attr_print(plaintext_stream, ATTR_FLAG_NONE,
+ SEND_ATTR_INT(MAIL_ATTR_STATUS, ready),
+ ATTR_TYPE_END) != 0
+ || vstream_fflush(plaintext_stream) != 0
+ || ready == 0) {
+ tlsp_request_read_event(plaintext_fd, tlsp_close_event,
+ TLSP_INIT_TIMEOUT, (void *) state);
+ return;
+ } else {
+ tlsp_request_read_event(plaintext_fd, tlsp_get_fd_event,
+ TLSP_INIT_TIMEOUT, (void *) state);
+ return;
+ }
+}
+
+/* tlsp_service - handle new client connection */
+
+static void tlsp_service(VSTREAM *plaintext_stream,
+ char *service,
+ char **argv)
+{
+ TLSP_STATE *state;
+ int plaintext_fd = vstream_fileno(plaintext_stream);
+
+ /*
+ * Sanity check. This service takes no command-line arguments.
+ */
+ if (argv[0])
+ msg_fatal("unexpected command-line argument: %s", argv[0]);
+
+ /*
+ * This program handles multiple connections, so it must not block. We
+ * use event-driven code for all operations that introduce latency.
+ * Except that attribute lists are sent/received synchronously, once the
+ * socket is found to be ready for transmission.
+ */
+ non_blocking(plaintext_fd, NON_BLOCKING);
+ vstream_control(plaintext_stream,
+ CA_VSTREAM_CTL_PATH("plaintext"),
+ CA_VSTREAM_CTL_TIMEOUT(5),
+ CA_VSTREAM_CTL_END);
+
+ (void) attr_print(plaintext_stream, ATTR_FLAG_NONE,
+ SEND_ATTR_STR(MAIL_ATTR_PROTO, MAIL_ATTR_PROTO_TLSPROXY),
+ ATTR_TYPE_END);
+ if (vstream_fflush(plaintext_stream) != 0)
+ msg_warn("write %s attribute: %m", MAIL_ATTR_PROTO);
+
+ /*
+ * Receive postscreen's remote SMTP client address/port and socket.
+ */
+ state = tlsp_state_create(service, plaintext_stream);
+ tlsp_request_read_event(plaintext_fd, tlsp_get_request_event,
+ TLSP_INIT_TIMEOUT, (void *) state);
+}
+
+/* pre_jail_init_server - pre-jail initialization */
+
+static void pre_jail_init_server(void)
+{
+ TLS_SERVER_INIT_PROPS props;
+ const char *cert_file;
+ int have_server_cert;
+ int no_server_cert_ok;
+ int require_server_cert;
+
+ /*
+ * The code in this routine is pasted literally from smtpd(8). I am not
+ * going to sanitize this because doing so surely will break things in
+ * unexpected ways.
+ */
+ if (*var_tlsp_tls_level) {
+ switch (tls_level_lookup(var_tlsp_tls_level)) {
+ default:
+ msg_fatal("Invalid TLS level \"%s\"", var_tlsp_tls_level);
+ /* NOTREACHED */
+ break;
+ case TLS_LEV_SECURE:
+ case TLS_LEV_VERIFY:
+ case TLS_LEV_FPRINT:
+ msg_warn("%s: unsupported TLS level \"%s\", using \"encrypt\"",
+ VAR_TLSP_TLS_LEVEL, var_tlsp_tls_level);
+ /* FALLTHROUGH */
+ case TLS_LEV_ENCRYPT:
+ var_tlsp_enforce_tls = var_tlsp_use_tls = 1;
+ break;
+ case TLS_LEV_MAY:
+ var_tlsp_enforce_tls = 0;
+ var_tlsp_use_tls = 1;
+ break;
+ case TLS_LEV_NONE:
+ var_tlsp_enforce_tls = var_tlsp_use_tls = 0;
+ break;
+ }
+ }
+ var_tlsp_use_tls = var_tlsp_use_tls || var_tlsp_enforce_tls;
+ if (!var_tlsp_use_tls) {
+ msg_warn("TLS server role is disabled with %s or %s",
+ VAR_TLSP_TLS_LEVEL, VAR_TLSP_USE_TLS);
+ return;
+ }
+
+ /*
+ * Load TLS keys before dropping privileges.
+ *
+ * Can't use anonymous ciphers if we want client certificates. Must use
+ * anonymous ciphers if we have no certificates.
+ */
+ ask_client_cert = require_server_cert =
+ (var_tlsp_tls_ask_ccert
+ || (var_tlsp_enforce_tls && var_tlsp_tls_req_ccert));
+ if (strcasecmp(var_tlsp_tls_cert_file, "none") == 0) {
+ no_server_cert_ok = 1;
+ cert_file = "";
+ } else {
+ no_server_cert_ok = 0;
+ cert_file = var_tlsp_tls_cert_file;
+ }
+ have_server_cert =
+ (*cert_file || *var_tlsp_tls_dcert_file || *var_tlsp_tls_eccert_file);
+
+ if (*var_tlsp_tls_chain_files != 0) {
+ if (!have_server_cert)
+ have_server_cert = 1;
+ else
+ msg_warn("Both %s and one or more of the legacy "
+ " %s, %s or %s are non-empty; the legacy "
+ " parameters will be ignored",
+ VAR_TLSP_TLS_CHAIN_FILES,
+ VAR_TLSP_TLS_CERT_FILE,
+ VAR_TLSP_TLS_ECCERT_FILE,
+ VAR_TLSP_TLS_DCERT_FILE);
+ }
+ /* Some TLS configuration errors are not show stoppers. */
+ if (!have_server_cert && require_server_cert)
+ msg_warn("Need a server cert to request client certs");
+ if (!var_tlsp_enforce_tls && var_tlsp_tls_req_ccert)
+ msg_warn("Can't require client certs unless TLS is required");
+ /* After a show-stopper error, log a warning. */
+ if (have_server_cert || (no_server_cert_ok && !require_server_cert)) {
+
+ tls_pre_jail_init(TLS_ROLE_SERVER);
+
+ /*
+ * Large parameter lists are error-prone, so we emulate a language
+ * feature that C does not have natively: named parameter lists.
+ */
+ tlsp_server_ctx =
+ TLS_SERVER_INIT(&props,
+ log_param = VAR_TLSP_TLS_LOGLEVEL,
+ log_level = var_tlsp_tls_loglevel,
+ verifydepth = var_tlsp_tls_ccert_vd,
+ cache_type = TLS_MGR_SCACHE_SMTPD,
+ set_sessid = var_tlsp_tls_set_sessid,
+ chain_files = var_tlsp_tls_chain_files,
+ cert_file = cert_file,
+ key_file = var_tlsp_tls_key_file,
+ dcert_file = var_tlsp_tls_dcert_file,
+ dkey_file = var_tlsp_tls_dkey_file,
+ eccert_file = var_tlsp_tls_eccert_file,
+ eckey_file = var_tlsp_tls_eckey_file,
+ CAfile = var_tlsp_tls_CAfile,
+ CApath = var_tlsp_tls_CApath,
+ dh1024_param_file
+ = var_tlsp_tls_dh1024_param_file,
+ dh512_param_file
+ = var_tlsp_tls_dh512_param_file,
+ eecdh_grade = var_tlsp_tls_eecdh,
+ protocols = var_tlsp_enforce_tls ?
+ var_tlsp_tls_mand_proto :
+ var_tlsp_tls_proto,
+ ask_ccert = ask_client_cert,
+ mdalg = var_tlsp_tls_fpt_dgst);
+ } else {
+ msg_warn("No server certs available. TLS can't be enabled");
+ }
+
+ /*
+ * To maintain sanity, allow partial SSL_write() operations, and allow
+ * SSL_write() buffer pointers to change after a WANT_READ or WANT_WRITE
+ * result. This is based on OpenSSL developers talking on a mailing list,
+ * but is not supported by documentation. If this code stops working then
+ * no-one can be held responsible.
+ */
+ if (tlsp_server_ctx)
+ SSL_CTX_set_mode(tlsp_server_ctx->ssl_ctx,
+ SSL_MODE_ENABLE_PARTIAL_WRITE
+ | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
+}
+
+/* pre_jail_init_client - pre-jail initialization */
+
+static void pre_jail_init_client(void)
+{
+ int clnt_use_tls;
+
+ /*
+ * The cache with TLS_APPL_STATE instances for different TLS_CLIENT_INIT
+ * configurations.
+ */
+ tlsp_client_app_cache = htable_create(10);
+
+ /*
+ * Most sites don't use TLS client certs/keys. In that case, enabling
+ * tlsproxy-based connection caching is trivial.
+ *
+ * But some sites do use TLS client certs/keys, and that is challenging when
+ * tlsproxy runs in a post-jail environment: chroot breaks pathname
+ * resolution, and an unprivileged process should not be able to open
+ * files with secrets. The workaround: assume that most of those sites
+ * will use a fixed TLS client identity. In that case, tlsproxy can load
+ * the corresponding certs/keys at pre-jail time, so that secrets can
+ * remain read-only for root. As long as the tlsproxy pre-jail TLS client
+ * configuration with cert or key pathnames is the same as the one used
+ * in the Postfix SMTP client, sites can selectively or globally enable
+ * tlsproxy-based connection caching without additional TLS
+ * configuration.
+ *
+ * Loading one TLS client configuration at pre-jail time is not sufficient
+ * for the minority of sites that want to use TLS connection caching with
+ * multiple TLS client identities. To alert the operator, tlsproxy will
+ * log a warning when a TLS_CLIENT_INIT message specifies a different
+ * configuration than the tlsproxy pre-jail client configuration, and
+ * that different configuration specifies file/directory pathname
+ * arguments. The workaround is to have one tlsproxy process per TLS
+ * client identity.
+ *
+ * The general solution for single-identity or multi-identity clients is to
+ * stop loading certs and keys from individual files. Instead, have a
+ * cert/key map, indexed by client identity, read-only by root. After
+ * opening the map as root at pre-jail time, tlsproxy can read certs/keys
+ * on-the-fly as an unprivileged process at post-jail time. This is the
+ * approach that was already proposed for server-side SNI support, and it
+ * could be reused here. It would also end the proliferation of RSA
+ * cert/key parameters, DSA cert/key parameters, EC cert/key parameters,
+ * and so on.
+ *
+ * Horror: In order to create the same pre-jail TLS client context as the
+ * one used in the Postfix SMTP client, we have to duplicate intricate
+ * SMTP client code, including a handful configuration parameters that
+ * tlsproxy does not need. We must duplicate the logic, so that we only
+ * load certs and keys when the SMTP client would load them.
+ */
+ if (*var_tlsp_clnt_level != 0)
+ switch (tls_level_lookup(var_tlsp_clnt_level)) {
+ case TLS_LEV_SECURE:
+ case TLS_LEV_VERIFY:
+ case TLS_LEV_DANE_ONLY:
+ case TLS_LEV_FPRINT:
+ case TLS_LEV_ENCRYPT:
+ var_tlsp_clnt_use_tls = var_tlsp_clnt_enforce_tls = 1;
+ break;
+ case TLS_LEV_DANE:
+ case TLS_LEV_MAY:
+ var_tlsp_clnt_use_tls = 1;
+ var_tlsp_clnt_enforce_tls = 0;
+ break;
+ case TLS_LEV_NONE:
+ var_tlsp_clnt_use_tls = var_tlsp_clnt_enforce_tls = 0;
+ break;
+ default:
+ /* tls_level_lookup() logs no warning. */
+ /* session_tls_init() assumes that var_tlsp_clnt_level is sane. */
+ msg_fatal("Invalid TLS level \"%s\"", var_tlsp_clnt_level);
+ }
+ clnt_use_tls = (var_tlsp_clnt_use_tls || var_tlsp_clnt_enforce_tls);
+
+ /*
+ * Initialize the TLS data before entering the chroot jail.
+ */
+ if (clnt_use_tls || var_tlsp_clnt_per_site[0] || var_tlsp_clnt_policy[0]) {
+ TLS_CLIENT_PARAMS tls_params;
+ TLS_CLIENT_INIT_PROPS init_props;
+
+ tls_pre_jail_init(TLS_ROLE_CLIENT);
+
+ /*
+ * We get stronger type safety and a cleaner interface by combining
+ * the various parameters into a single tls_client_props structure.
+ *
+ * Large parameter lists are error-prone, so we emulate a language
+ * feature that C does not have natively: named parameter lists.
+ */
+ (void) tls_proxy_client_param_from_config(&tls_params);
+ (void) TLS_CLIENT_INIT_ARGS(&init_props,
+ log_param = var_tlsp_clnt_logparam,
+ log_level = var_tlsp_clnt_loglevel,
+ verifydepth = var_tlsp_clnt_scert_vd,
+ cache_type = TLS_MGR_SCACHE_SMTP,
+ chain_files = var_tlsp_clnt_chain_files,
+ cert_file = var_tlsp_clnt_cert_file,
+ key_file = var_tlsp_clnt_key_file,
+ dcert_file = var_tlsp_clnt_dcert_file,
+ dkey_file = var_tlsp_clnt_dkey_file,
+ eccert_file = var_tlsp_clnt_eccert_file,
+ eckey_file = var_tlsp_clnt_eckey_file,
+ CAfile = var_tlsp_clnt_CAfile,
+ CApath = var_tlsp_clnt_CApath,
+ mdalg = var_tlsp_clnt_fpt_dgst);
+ if (tlsp_client_init(&tls_params, &init_props) == 0)
+ msg_warn("TLS client initialization failed");
+ }
+}
+
+/* pre_jail_init - pre-jail initialization */
+
+static void pre_jail_init(char *unused_name, char **unused_argv)
+{
+
+ /*
+ * Initialize roles separately.
+ */
+ pre_jail_init_server();
+ pre_jail_init_client();
+
+ /*
+ * tlsp_client_init() needs to know if it is called pre-jail or
+ * post-jail.
+ */
+ tlsp_pre_jail_done = 1;
+
+ /*
+ * Bug: TLS_CLIENT_PARAMS attributes are not used when creating a
+ * TLS_APPL_STATE instance; we can only warn about attribute mismatches.
+ */
+ tlsp_params_mismatch_filter = been_here_init(BH_BOUND_NONE, BH_FLAG_NONE);
+}
+
+MAIL_VERSION_STAMP_DECLARE;
+
+/* main - the main program */
+
+int main(int argc, char **argv)
+{
+
+ /*
+ * Each table below initializes the named variables to their implicit
+ * default value, or to the explicit value in main.cf or master.cf. Here,
+ * "compat" means that a table initializes a variable "smtpd_blah" or
+ * "smtp_blah" that provides the implicit default value for variable
+ * "tlsproxy_blah" which is initialized by a different table. To make
+ * this work, the variables in a "compat" table must be initialized
+ * before the variables in the corresponding non-compat table.
+ */
+ static const CONFIG_INT_TABLE compat_int_table[] = {
+ VAR_SMTPD_TLS_CCERT_VD, DEF_SMTPD_TLS_CCERT_VD, &var_smtpd_tls_ccert_vd, 0, 0,
+ VAR_SMTP_TLS_SCERT_VD, DEF_SMTP_TLS_SCERT_VD, &var_smtp_tls_scert_vd, 0, 0,
+ 0,
+ };
+ static const CONFIG_NINT_TABLE nint_table[] = {
+ VAR_TLSP_TLS_CCERT_VD, DEF_TLSP_TLS_CCERT_VD, &var_tlsp_tls_ccert_vd, 0, 0,
+ VAR_TLSP_CLNT_SCERT_VD, DEF_TLSP_CLNT_SCERT_VD, &var_tlsp_clnt_scert_vd, 0, 0,
+ 0,
+ };
+ static const CONFIG_TIME_TABLE time_table[] = {
+ VAR_TLSP_WATCHDOG, DEF_TLSP_WATCHDOG, &var_tlsp_watchdog, 10, 0,
+ 0,
+ };
+ static const CONFIG_BOOL_TABLE compat_bool_table[] = {
+ VAR_SMTPD_USE_TLS, DEF_SMTPD_USE_TLS, &var_smtpd_use_tls,
+ VAR_SMTPD_ENFORCE_TLS, DEF_SMTPD_ENFORCE_TLS, &var_smtpd_enforce_tls,
+ VAR_SMTPD_TLS_ACERT, DEF_SMTPD_TLS_ACERT, &var_smtpd_tls_ask_ccert,
+ VAR_SMTPD_TLS_RCERT, DEF_SMTPD_TLS_RCERT, &var_smtpd_tls_req_ccert,
+ VAR_SMTPD_TLS_SET_SESSID, DEF_SMTPD_TLS_SET_SESSID, &var_smtpd_tls_set_sessid,
+ VAR_SMTP_USE_TLS, DEF_SMTP_USE_TLS, &var_smtp_use_tls,
+ VAR_SMTP_ENFORCE_TLS, DEF_SMTP_ENFORCE_TLS, &var_smtp_enforce_tls,
+ 0,
+ };
+ static const CONFIG_NBOOL_TABLE nbool_table[] = {
+ VAR_TLSP_USE_TLS, DEF_TLSP_USE_TLS, &var_tlsp_use_tls,
+ VAR_TLSP_ENFORCE_TLS, DEF_TLSP_ENFORCE_TLS, &var_tlsp_enforce_tls,
+ VAR_TLSP_TLS_ACERT, DEF_TLSP_TLS_ACERT, &var_tlsp_tls_ask_ccert,
+ VAR_TLSP_TLS_RCERT, DEF_TLSP_TLS_RCERT, &var_tlsp_tls_req_ccert,
+ VAR_TLSP_TLS_SET_SESSID, DEF_TLSP_TLS_SET_SESSID, &var_tlsp_tls_set_sessid,
+ VAR_TLSP_CLNT_USE_TLS, DEF_TLSP_CLNT_USE_TLS, &var_tlsp_clnt_use_tls,
+ VAR_TLSP_CLNT_ENFORCE_TLS, DEF_TLSP_CLNT_ENFORCE_TLS, &var_tlsp_clnt_enforce_tls,
+ 0,
+ };
+ static const CONFIG_STR_TABLE compat_str_table[] = {
+ VAR_SMTPD_TLS_CHAIN_FILES, DEF_SMTPD_TLS_CHAIN_FILES, &var_smtpd_tls_chain_files, 0, 0,
+ VAR_SMTPD_TLS_CERT_FILE, DEF_SMTPD_TLS_CERT_FILE, &var_smtpd_tls_cert_file, 0, 0,
+ VAR_SMTPD_TLS_KEY_FILE, DEF_SMTPD_TLS_KEY_FILE, &var_smtpd_tls_key_file, 0, 0,
+ VAR_SMTPD_TLS_DCERT_FILE, DEF_SMTPD_TLS_DCERT_FILE, &var_smtpd_tls_dcert_file, 0, 0,
+ VAR_SMTPD_TLS_DKEY_FILE, DEF_SMTPD_TLS_DKEY_FILE, &var_smtpd_tls_dkey_file, 0, 0,
+ VAR_SMTPD_TLS_ECCERT_FILE, DEF_SMTPD_TLS_ECCERT_FILE, &var_smtpd_tls_eccert_file, 0, 0,
+ VAR_SMTPD_TLS_ECKEY_FILE, DEF_SMTPD_TLS_ECKEY_FILE, &var_smtpd_tls_eckey_file, 0, 0,
+ VAR_SMTPD_TLS_CA_FILE, DEF_SMTPD_TLS_CA_FILE, &var_smtpd_tls_CAfile, 0, 0,
+ VAR_SMTPD_TLS_CA_PATH, DEF_SMTPD_TLS_CA_PATH, &var_smtpd_tls_CApath, 0, 0,
+ VAR_SMTPD_TLS_CIPH, DEF_SMTPD_TLS_CIPH, &var_smtpd_tls_ciph, 1, 0,
+ VAR_SMTPD_TLS_MAND_CIPH, DEF_SMTPD_TLS_MAND_CIPH, &var_smtpd_tls_mand_ciph, 1, 0,
+ VAR_SMTPD_TLS_EXCL_CIPH, DEF_SMTPD_TLS_EXCL_CIPH, &var_smtpd_tls_excl_ciph, 0, 0,
+ VAR_SMTPD_TLS_MAND_EXCL, DEF_SMTPD_TLS_MAND_EXCL, &var_smtpd_tls_mand_excl, 0, 0,
+ VAR_SMTPD_TLS_PROTO, DEF_SMTPD_TLS_PROTO, &var_smtpd_tls_proto, 0, 0,
+ VAR_SMTPD_TLS_MAND_PROTO, DEF_SMTPD_TLS_MAND_PROTO, &var_smtpd_tls_mand_proto, 0, 0,
+ VAR_SMTPD_TLS_512_FILE, DEF_SMTPD_TLS_512_FILE, &var_smtpd_tls_dh512_param_file, 0, 0,
+ VAR_SMTPD_TLS_1024_FILE, DEF_SMTPD_TLS_1024_FILE, &var_smtpd_tls_dh1024_param_file, 0, 0,
+ VAR_SMTPD_TLS_EECDH, DEF_SMTPD_TLS_EECDH, &var_smtpd_tls_eecdh, 1, 0,
+ VAR_SMTPD_TLS_FPT_DGST, DEF_SMTPD_TLS_FPT_DGST, &var_smtpd_tls_fpt_dgst, 1, 0,
+ VAR_SMTPD_TLS_LOGLEVEL, DEF_SMTPD_TLS_LOGLEVEL, &var_smtpd_tls_loglevel, 0, 0,
+ VAR_SMTPD_TLS_LEVEL, DEF_SMTPD_TLS_LEVEL, &var_smtpd_tls_level, 0, 0,
+ VAR_SMTP_TLS_CHAIN_FILES, DEF_SMTP_TLS_CHAIN_FILES, &var_smtp_tls_chain_files, 0, 0,
+ VAR_SMTP_TLS_CERT_FILE, DEF_SMTP_TLS_CERT_FILE, &var_smtp_tls_cert_file, 0, 0,
+ VAR_SMTP_TLS_KEY_FILE, DEF_SMTP_TLS_KEY_FILE, &var_smtp_tls_key_file, 0, 0,
+ VAR_SMTP_TLS_DCERT_FILE, DEF_SMTP_TLS_DCERT_FILE, &var_smtp_tls_dcert_file, 0, 0,
+ VAR_SMTP_TLS_DKEY_FILE, DEF_SMTP_TLS_DKEY_FILE, &var_smtp_tls_dkey_file, 0, 0,
+ VAR_SMTP_TLS_CA_FILE, DEF_SMTP_TLS_CA_FILE, &var_smtp_tls_CAfile, 0, 0,
+ VAR_SMTP_TLS_CA_PATH, DEF_SMTP_TLS_CA_PATH, &var_smtp_tls_CApath, 0, 0,
+ VAR_SMTP_TLS_FPT_DGST, DEF_SMTP_TLS_FPT_DGST, &var_smtp_tls_fpt_dgst, 1, 0,
+ VAR_SMTP_TLS_ECCERT_FILE, DEF_SMTP_TLS_ECCERT_FILE, &var_smtp_tls_eccert_file, 0, 0,
+ VAR_SMTP_TLS_ECKEY_FILE, DEF_SMTP_TLS_ECKEY_FILE, &var_smtp_tls_eckey_file, 0, 0,
+ VAR_SMTP_TLS_LOGLEVEL, DEF_SMTP_TLS_LOGLEVEL, &var_smtp_tls_loglevel, 0, 0,
+ VAR_SMTP_TLS_PER_SITE, DEF_SMTP_TLS_PER_SITE, &var_smtp_tls_per_site, 0, 0,
+ VAR_SMTP_TLS_LEVEL, DEF_SMTP_TLS_LEVEL, &var_smtp_tls_level, 0, 0,
+ VAR_SMTP_TLS_POLICY, DEF_SMTP_TLS_POLICY, &var_smtp_tls_policy, 0, 0,
+ 0,
+ };
+ static const CONFIG_STR_TABLE str_table[] = {
+ VAR_TLSP_TLS_CHAIN_FILES, DEF_TLSP_TLS_CHAIN_FILES, &var_tlsp_tls_chain_files, 0, 0,
+ VAR_TLSP_TLS_CERT_FILE, DEF_TLSP_TLS_CERT_FILE, &var_tlsp_tls_cert_file, 0, 0,
+ VAR_TLSP_TLS_KEY_FILE, DEF_TLSP_TLS_KEY_FILE, &var_tlsp_tls_key_file, 0, 0,
+ VAR_TLSP_TLS_DCERT_FILE, DEF_TLSP_TLS_DCERT_FILE, &var_tlsp_tls_dcert_file, 0, 0,
+ VAR_TLSP_TLS_DKEY_FILE, DEF_TLSP_TLS_DKEY_FILE, &var_tlsp_tls_dkey_file, 0, 0,
+ VAR_TLSP_TLS_ECCERT_FILE, DEF_TLSP_TLS_ECCERT_FILE, &var_tlsp_tls_eccert_file, 0, 0,
+ VAR_TLSP_TLS_ECKEY_FILE, DEF_TLSP_TLS_ECKEY_FILE, &var_tlsp_tls_eckey_file, 0, 0,
+ VAR_TLSP_TLS_CA_FILE, DEF_TLSP_TLS_CA_FILE, &var_tlsp_tls_CAfile, 0, 0,
+ VAR_TLSP_TLS_CA_PATH, DEF_TLSP_TLS_CA_PATH, &var_tlsp_tls_CApath, 0, 0,
+ VAR_TLSP_TLS_CIPH, DEF_TLSP_TLS_CIPH, &var_tlsp_tls_ciph, 1, 0,
+ VAR_TLSP_TLS_MAND_CIPH, DEF_TLSP_TLS_MAND_CIPH, &var_tlsp_tls_mand_ciph, 1, 0,
+ VAR_TLSP_TLS_EXCL_CIPH, DEF_TLSP_TLS_EXCL_CIPH, &var_tlsp_tls_excl_ciph, 0, 0,
+ VAR_TLSP_TLS_MAND_EXCL, DEF_TLSP_TLS_MAND_EXCL, &var_tlsp_tls_mand_excl, 0, 0,
+ VAR_TLSP_TLS_PROTO, DEF_TLSP_TLS_PROTO, &var_tlsp_tls_proto, 0, 0,
+ VAR_TLSP_TLS_MAND_PROTO, DEF_TLSP_TLS_MAND_PROTO, &var_tlsp_tls_mand_proto, 0, 0,
+ VAR_TLSP_TLS_512_FILE, DEF_TLSP_TLS_512_FILE, &var_tlsp_tls_dh512_param_file, 0, 0,
+ VAR_TLSP_TLS_1024_FILE, DEF_TLSP_TLS_1024_FILE, &var_tlsp_tls_dh1024_param_file, 0, 0,
+ VAR_TLSP_TLS_EECDH, DEF_TLSP_TLS_EECDH, &var_tlsp_tls_eecdh, 1, 0,
+ VAR_TLSP_TLS_FPT_DGST, DEF_TLSP_TLS_FPT_DGST, &var_tlsp_tls_fpt_dgst, 1, 0,
+ VAR_TLSP_TLS_LOGLEVEL, DEF_TLSP_TLS_LOGLEVEL, &var_tlsp_tls_loglevel, 0, 0,
+ VAR_TLSP_TLS_LEVEL, DEF_TLSP_TLS_LEVEL, &var_tlsp_tls_level, 0, 0,
+ VAR_TLSP_CLNT_LOGLEVEL, DEF_TLSP_CLNT_LOGLEVEL, &var_tlsp_clnt_loglevel, 0, 0,
+ VAR_TLSP_CLNT_LOGPARAM, DEF_TLSP_CLNT_LOGPARAM, &var_tlsp_clnt_logparam, 0, 0,
+ VAR_TLSP_CLNT_CHAIN_FILES, DEF_TLSP_CLNT_CHAIN_FILES, &var_tlsp_clnt_chain_files, 0, 0,
+ VAR_TLSP_CLNT_CERT_FILE, DEF_TLSP_CLNT_CERT_FILE, &var_tlsp_clnt_cert_file, 0, 0,
+ VAR_TLSP_CLNT_KEY_FILE, DEF_TLSP_CLNT_KEY_FILE, &var_tlsp_clnt_key_file, 0, 0,
+ VAR_TLSP_CLNT_DCERT_FILE, DEF_TLSP_CLNT_DCERT_FILE, &var_tlsp_clnt_dcert_file, 0, 0,
+ VAR_TLSP_CLNT_DKEY_FILE, DEF_TLSP_CLNT_DKEY_FILE, &var_tlsp_clnt_dkey_file, 0, 0,
+ VAR_TLSP_CLNT_ECCERT_FILE, DEF_TLSP_CLNT_ECCERT_FILE, &var_tlsp_clnt_eccert_file, 0, 0,
+ VAR_TLSP_CLNT_ECKEY_FILE, DEF_TLSP_CLNT_ECKEY_FILE, &var_tlsp_clnt_eckey_file, 0, 0,
+ VAR_TLSP_CLNT_CAFILE, DEF_TLSP_CLNT_CAFILE, &var_tlsp_clnt_CAfile, 0, 0,
+ VAR_TLSP_CLNT_CAPATH, DEF_TLSP_CLNT_CAPATH, &var_tlsp_clnt_CApath, 0, 0,
+ VAR_TLSP_CLNT_FPT_DGST, DEF_TLSP_CLNT_FPT_DGST, &var_tlsp_clnt_fpt_dgst, 1, 0,
+ VAR_TLSP_CLNT_LEVEL, DEF_TLSP_CLNT_LEVEL, &var_tlsp_clnt_level, 0, 0,
+ VAR_TLSP_CLNT_PER_SITE, DEF_TLSP_CLNT_PER_SITE, &var_tlsp_clnt_per_site, 0, 0,
+ VAR_TLSP_CLNT_POLICY, DEF_TLSP_CLNT_POLICY, &var_tlsp_clnt_policy, 0, 0,
+ 0,
+ };
+
+ /*
+ * Fingerprint executables and core dumps.
+ */
+ MAIL_VERSION_STAMP_ALLOCATE;
+
+ /*
+ * Pass control to the event-driven service skeleton.
+ */
+ event_server_main(argc, argv, tlsp_service,
+ CA_MAIL_SERVER_INT_TABLE(compat_int_table),
+ CA_MAIL_SERVER_NINT_TABLE(nint_table),
+ CA_MAIL_SERVER_STR_TABLE(compat_str_table),
+ CA_MAIL_SERVER_STR_TABLE(str_table),
+ CA_MAIL_SERVER_BOOL_TABLE(compat_bool_table),
+ CA_MAIL_SERVER_NBOOL_TABLE(nbool_table),
+ CA_MAIL_SERVER_TIME_TABLE(time_table),
+ CA_MAIL_SERVER_PRE_INIT(pre_jail_init),
+ CA_MAIL_SERVER_SLOW_EXIT(tlsp_drain),
+ CA_MAIL_SERVER_RETIRE_ME,
+ CA_MAIL_SERVER_WATCHDOG(&var_tlsp_watchdog),
+ CA_MAIL_SERVER_UNLIMITED,
+ 0);
+}
+
+#else
+
+/* tlsp_service - respond to external trigger(s), non-TLS version */
+
+static void tlsp_service(VSTREAM *stream, char *unused_service,
+ char **unused_argv)
+{
+ msg_info("TLS support is not compiled in -- exiting");
+ event_server_disconnect(stream);
+}
+
+/* main - the main program */
+
+int main(int argc, char **argv)
+{
+
+ /*
+ * We can't simply use msg_fatal() here, because the logging hasn't been
+ * initialized. The text would disappear because stderr is redirected to
+ * /dev/null.
+ *
+ * We invoke event_server_main() to complete program initialization
+ * (including logging) and then invoke the tlsp_service() routine to log
+ * the message that says why this program will not run.
+ */
+ event_server_main(argc, argv, tlsp_service,
+ 0);
+}
+
+#endif
diff --git a/src/tlsproxy/tlsproxy.h b/src/tlsproxy/tlsproxy.h
new file mode 100644
index 0000000..eacbb1f
--- /dev/null
+++ b/src/tlsproxy/tlsproxy.h
@@ -0,0 +1,69 @@
+/*++
+/* NAME
+/* tlsproxy 3h
+/* SUMMARY
+/* tlsproxy internal interfaces
+/* SYNOPSIS
+/* #include <tlsproxy.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+ * Utility library.
+ */
+#include <vstream.h>
+#include <nbbio.h>
+
+ /*
+ * TLS library.
+ */
+#include <tls.h>
+
+ /*
+ * Internal interface.
+ */
+typedef struct {
+ int flags; /* see below */
+ int req_flags; /* request flags, see tls_proxy.h */
+ int is_server_role; /* avoid clumsy handler code */
+ char *service; /* argv[0] */
+ VSTREAM *plaintext_stream; /* local peer: postscreen(8), etc. */
+ NBBIO *plaintext_buf; /* plaintext buffer */
+ int ciphertext_fd; /* remote peer */
+ EVENT_NOTIFY_FN ciphertext_timer; /* kludge */
+ int timeout; /* read/write time limit */
+ int handshake_timeout; /* in-handshake time limit */
+ int session_timeout; /* post-handshake time limit */
+ char *remote_endpt; /* printable remote endpoint */
+ char *server_id; /* cache management */
+ TLS_APPL_STATE *appl_state; /* libtls state */
+ TLS_SESS_STATE *tls_context; /* libtls state */
+ int ssl_last_err; /* TLS I/O state */
+ TLS_CLIENT_PARAMS *tls_params; /* globals not part of init_props */
+ TLS_SERVER_INIT_PROPS *server_init_props;
+ TLS_SERVER_START_PROPS *server_start_props;
+ TLS_CLIENT_INIT_PROPS *client_init_props;
+ TLS_CLIENT_START_PROPS *client_start_props;
+} TLSP_STATE;
+
+#define TLSP_FLAG_DO_HANDSHAKE (1<<0)
+#define TLSP_FLAG_NO_MORE_CIPHERTEXT_IO (1<<1) /* overrides DO_HANDSHAKE */
+
+extern TLSP_STATE *tlsp_state_create(const char *, VSTREAM *);
+extern void tlsp_state_free(TLSP_STATE *);
+
+/* 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
+/*--*/
diff --git a/src/tlsproxy/tlsproxy_state.c b/src/tlsproxy/tlsproxy_state.c
new file mode 100644
index 0000000..df6cbda
--- /dev/null
+++ b/src/tlsproxy/tlsproxy_state.c
@@ -0,0 +1,169 @@
+/*++
+/* NAME
+/* tlsproxy_state 3
+/* SUMMARY
+/* Postfix SMTP server
+/* SYNOPSIS
+/* #include <tlsproxy.h>
+/*
+/* TLSP_STATE *tlsp_state_create(service, plaintext_stream)
+/* const char *service;
+/* VSTREAM *plaintext_stream;
+/*
+/* void tlsp_state_free(state)
+/* TLSP_STATE *state;
+/* DESCRIPTION
+/* This module provides TLSP_STATE constructor and destructor
+/* routines.
+/*
+/* tlsp_state_create() initializes session context.
+/*
+/* tlsp_state_free() destroys session context. If the handshake
+/* was in progress, it logs a 'handshake failed' message.
+/*
+/* Arguments:
+/* .IP service
+/* The service name for the TLS library. This argument is copied.
+/* The destructor will automatically destroy the string.
+/* .IP plaintext_stream
+/* The VSTREAM between postscreen(8) and tlsproxy(8).
+/* The destructor will automatically close the stream.
+/* .PP
+/* Other structure members are set by the application. The
+/* text below describes how the TLSP_STATE destructor
+/* disposes of them.
+/* .IP plaintext_buf
+/* NBBIO for plaintext I/O.
+/* The destructor will automatically turn off read/write/timeout
+/* events and destroy the NBBIO.
+/* .IP ciphertext_fd
+/* The file handle for the remote SMTP client socket.
+/* The destructor will automatically turn off read/write events
+/* and close the file handle.
+/* .IP ciphertext_timer
+/* The destructor will automatically turn off this time event.
+/* .IP timeout
+/* Time limit for plaintext and ciphertext I/O.
+/* .IP remote_endpt
+/* Printable remote endpoint name.
+/* The destructor will automatically destroy the string.
+/* .IP server_id
+/* TLS session cache identifier.
+/* The destructor will automatically destroy the string.
+/* DIAGNOSTICS
+/* All errors are fatal.
+/* 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>
+
+ /*
+ * Utility library.
+ */
+#include <msg.h>
+#include <mymalloc.h>
+#include <nbbio.h>
+
+ /*
+ * Master library.
+ */
+#include <mail_server.h>
+
+ /*
+ * TLS library.
+ */
+#ifdef USE_TLS
+#define TLS_INTERNAL /* XXX */
+#include <tls.h>
+#include <tls_proxy.h>
+
+ /*
+ * Application-specific.
+ */
+#include <tlsproxy.h>
+
+/* tlsp_state_create - create TLS proxy state object */
+
+TLSP_STATE *tlsp_state_create(const char *service,
+ VSTREAM *plaintext_stream)
+{
+ TLSP_STATE *state = (TLSP_STATE *) mymalloc(sizeof(*state));
+
+ state->flags = TLSP_FLAG_DO_HANDSHAKE;
+ state->service = mystrdup(service);
+ state->plaintext_stream = plaintext_stream;
+ state->plaintext_buf = 0;
+ state->ciphertext_fd = -1;
+ state->ciphertext_timer = 0;
+ state->timeout = -1;
+ state->remote_endpt = 0;
+ state->server_id = 0;
+ state->tls_context = 0;
+ state->tls_params = 0;
+ state->server_init_props = 0;
+ state->server_start_props = 0;
+ state->client_init_props = 0;
+ state->client_start_props = 0;
+
+ return (state);
+}
+
+/* tlsp_state_free - destroy state objects, connection and events */
+
+void tlsp_state_free(TLSP_STATE *state)
+{
+ /* Don't log failure after plaintext EOF. */
+ if (state->remote_endpt && state->server_id
+ && (state->flags & TLSP_FLAG_DO_HANDSHAKE))
+ msg_info("TLS handshake failed for service=%s peer=%s",
+ state->server_id, state->remote_endpt);
+ myfree(state->service);
+ if (state->plaintext_buf) /* turns off plaintext events */
+ nbbio_free(state->plaintext_buf);
+ else
+ event_disable_readwrite(vstream_fileno(state->plaintext_stream));
+ event_server_disconnect(state->plaintext_stream);
+ if (state->ciphertext_fd >= 0) {
+ event_disable_readwrite(state->ciphertext_fd);
+ (void) close(state->ciphertext_fd);
+ }
+ if (state->ciphertext_timer)
+ event_cancel_timer(state->ciphertext_timer, (void *) state);
+ if (state->remote_endpt) {
+ msg_info("DISCONNECT %s", state->remote_endpt);
+ myfree(state->remote_endpt);
+ }
+ if (state->server_id)
+ myfree(state->server_id);
+ if (state->tls_context)
+ tls_free_context(state->tls_context);
+ if (state->tls_params)
+ tls_proxy_client_param_free(state->tls_params);
+ if (state->server_init_props)
+ tls_proxy_server_init_free(state->server_init_props);
+ if (state->server_start_props)
+ tls_proxy_server_start_free(state->server_start_props);
+ if (state->client_init_props)
+ tls_proxy_client_init_free(state->client_init_props);
+ if (state->client_start_props)
+ tls_proxy_client_start_free(state->client_start_props);
+ myfree((void *) state);
+}
+
+#endif
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