/* $NetBSD: tlsproxy.c,v 1.5 2022/10/08 16:12:50 christos Exp $ */
/*++
/* 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.
/* 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