qmail/netqmail-1.06-tls-20190517-remote.patch

Frederik Vermeulen <qmail-tls akrul inoa.net> 20190517
http://inoa.net/qmail-tls/

This patch implements RFC 3207 in qmail. 
This means you can get SSL or TLS encrypted and 
authenticated SMTP between the MTAs and from MUA to MTA. 
The code is considered experimental (but has worked for
many since its first release on 1999-03-21).

Usage: - install OpenSSL-1.1.0 http://www.openssl.org/ or later
         (any version since 0.9.8 is presumed to work)
       - apply patch to netqmail-1.06 http://qmail.org/netqmail
         The patches to qmail-remote.c and qmail-smtpd.c can be applied 
         separately.
       - provide a server certificate in /var/qmail/control/servercert.pem.
         "make cert" makes a self-signed certificate.
         "make cert-req" makes a certificate request.
         Note: you can add the CA certificate and intermediate
         certs to the end of servercert.pem.
       - replace qmail-smtpd and/or qmail-remote binary
       - verify operation (header information should show
         something like
         "Received [..] with (DHE-RSA-AES256-SHA encrypted) SMTP;")

Optional: - when DEBUG is defined, some extra TLS info will be logged
          - qmail-remote will authenticate with the certificate in
            /var/qmail/control/clientcert.pem. By preference this is
            the same as servercert.pem, where nsCertType should be 
            == server,client or be a generic certificate (no usage specified). 
          - when a 2048 bit RSA key is provided in /var/qmail/control/rsa2048.pem,
            this key will be used instead of (slow) on-the-fly generation by
            qmail-smtpd. Idem for 2048 DH param in control/dh2048.pem.
            `make tmprsadh` does this.
            Periodical replacement can be done by crontab:
            01 01 * * * /var/qmail/bin/update_tmprsadh > /dev/null 2>&1
          - server authentication:
            qmail-remote requires authentication from servers for which
            /var/qmail/control/tlshosts/host.dom.ain.pem exists.
            The .pem file contains the validating CA certificates.
            One of the dNSName or the CommonName attributes have to match.
            WARNING: this option may cause mail to be delayed, bounced,
            doublebounced, and lost.
            If /var/qmail/control/tlshosts/exhaustivelist is present,
            the lists of hosts in /var/qmail/control/tlshosts is
            an exhaustive list of hosts TLS is tried on.
            If /var/qmail/control/notlshosts/host.dom.ain is present,
            no TLS is tried on this host.
          - client authentication:
            when relay rules would reject an incoming mail, 
            qmail-smtpd can allow the mail based on a presented cert.
            Certs are verified against a CA list in 
            /var/qmail/control/clientca.pem (eg. from
            http://curl.haxx.se/ca/cacert.pem)
            and the cert email-address has to match a line in
            /var/qmail/control/tlsclients. This email-address is logged
            in the headers. CRLs can be provided through 
            /var/qmail/control/clientcrl.pem.
          - cipher selection:
            qmail-remote: 
              openssl cipher string (`man ciphers`) read from 
              /var/qmail/control/tlsclientciphers
            qmail-smtpd: 
              openssl cipher string read from TLSCIPHERS environment variable
              (can vary based on client IP address e.g.)
              or if that is not available /var/qmail/control/tlsserverciphers
          - smtps (deprecated SMTP over TLS via port 465):
            qmail-remote: when connecting to port 465 
            qmail-smtpd: when SMTPS environment variable is not empty

Caveats: - do a `make clean` after patching
         - binaries dynamically linked with current openssl versions need
           recompilation when the shared openssl libs are upgraded.
         - this patch could conflict with other patches (notably those
           replacing \n with \r\n, which is a bad idea on encrypted links).
         - needs working /dev/urandom (or EGD for openssl versions >0.9.7)
           for seeding random number generator.
         - packagers should make sure that installing without a valid 
           servercert is impossible
         - when applied in combination with AUTH patch, AUTH patch
           should be applied first and first part of this patch
           will fail. This error can be ignored. Packagers should
           cut the first 12 lines of this patch to make a happy
           patch
         - `make tmprsadh` is recommended (or should I say required), 
           otherwise DH generation can be unpredictably slow
         - some need "-I/usr/kerberos/include" to be added in conf-cc

Copyright: GPL
           Links with OpenSSL
           Inspiration and code from examples in SSLeay (E. Young
           <eay@cryptsoft.com> and T. Hudson <tjh@cryptsoft.com>),
           stunnel (M. Trojnara <mtrojnar@ddc.daewoo.com.pl>),
           Postfix/TLS (L. Jaenicke <Lutz.Jaenicke@aet.tu-cottbus.de>),
           modssl (R. Engelschall <rse@engelschall.com>),
           openssl examples of E. Rescorla <ekr@rtfm.com>.

Bug reports: mailto:<qmail-tls akrul inoa.net>


>----< Cut the next 12 lines if applying over AUTH server patch >---<
--- qmail-1.03/qmail-smtpd.c	Mon Jun 15 03:53:16 1998
+++ qmail-1.03-tls/qmail-smtpd.c	Tue Jun 18 09:49:38 2002
@@ -229,7 +229,8 @@
 }
 void smtp_ehlo(arg) char *arg;
 {
-  smtp_greet("250-"); out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");
+  smtp_greet("250-");
+  out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");
   seenmail = 0; dohelo(arg);
 }
 void smtp_rset()
>----< Cut previous 12 lines if applying over AUTH server patch >---<



>----< The next 89 lines are the qmail-remote EHLO patch >---<
--- qmail-1.03/qmail-remote.c	Mon Jun 15 03:53:16 1998
+++ qmail-1.03-tls/qmail-remote.c	Sun Nov 24 13:05:20 2002
@@ -163,6 +163,59 @@ unsigned long smtpcode()
   return code;
 }
 
+#ifdef EHLO
+saa ehlokw = {0}; /* list of EHLO keywords and parameters */
+int maxehlokwlen = 0;
+
+unsigned long ehlo()
+{
+  stralloc *sa;
+  char *s, *e, *p;
+  unsigned long code;
+
+  if (ehlokw.len > maxehlokwlen) maxehlokwlen = ehlokw.len;
+  ehlokw.len = 0;
+
+# ifdef MXPS
+  if (type == 's') return 0;
+# endif
+
+  substdio_puts(&smtpto, "EHLO ");
+  substdio_put(&smtpto, helohost.s, helohost.len);
+  substdio_puts(&smtpto, "\r\n");
+  substdio_flush(&smtpto);
+
+  code = smtpcode();
+  if (code != 250) return code;
+
+  s = smtptext.s;
+  while (*s++ != '\n') ; /* skip the first line: contains the domain */
+
+  e = smtptext.s + smtptext.len - 6; /* 250-?\n */
+  while (s <= e)
+  {
+    if (!saa_readyplus(&ehlokw, 1)) temp_nomem();
+    sa = ehlokw.sa + ehlokw.len++;
+    if (ehlokw.len > maxehlokwlen) *sa = sauninit; else sa->len = 0;
+
+    /* smtptext is known to end in a '\n' */
+    for (p = (s += 4); ; ++p)
+      if (*p == '\n' || *p == ' ' || *p == '\t') {
+        if (!stralloc_catb(sa, s, p - s) || !stralloc_0(sa)) temp_nomem();
+        if (*p++ == '\n') break;
+        while (*p == ' ' || *p == '\t') ;
+        s = p;
+      }
+    s = p;
+    /* keyword should consist of alpha-num and '-'
+     * broken AUTH might use '=' instead of space */
+    for (p = sa->s; *p; ++p) if (*p == '=') { *p = 0; break; }
+  }
+
+  return 250;
+}
+#endif
+
 void outsmtptext()
 {
   int i; 
@@ -224,12 +277,26 @@ void smtp()
  
   if (smtpcode() != 220) quit("ZConnected to "," but greeting failed");
  
+#ifdef EHLO
+  code = ehlo();
+
+  if (code == 250) {
+    /* add EHLO response checks here */
+
+    /* and if EHLO failed, use HELO */
+  } else {
+#endif
+ 
   substdio_puts(&smtpto,"HELO ");
   substdio_put(&smtpto,helohost.s,helohost.len);
   substdio_puts(&smtpto,"\r\n");
   substdio_flush(&smtpto);
   if (smtpcode() != 250) quit("ZConnected to "," but my name was rejected");
  
+#ifdef EHLO
+  }
+#endif
+ 
   substdio_puts(&smtpto,"MAIL FROM:<");
   substdio_put(&smtpto,sender.s,sender.len);
   substdio_puts(&smtpto,">\r\n");
>----< Previous 89 lines are the qmail-remote EHLO patch >---<




--- netqmail-1.06-orig/qmail-remote.c	2019-04-08 15:26:13.100123364 +0000
+++ netqmail-1.06/qmail-remote.c	2019-04-02 08:01:50.176790637 +0000
@@ -48,6 +48,17 @@ saa reciplist = {0};
 
 struct ip_address partner;
 
+#ifdef TLS
+# include <sys/stat.h>
+# include "tls.h"
+# include "ssl_timeoutio.h"
+# include <openssl/x509v3.h>
+# define EHLO 1
+
+int tls_init();
+const char *ssl_err_str = 0;
+#endif 
+
 void out(s) char *s; { if (substdio_puts(subfdoutsmall,s) == -1) _exit(0); }
 void zero() { if (substdio_put(subfdoutsmall,"\0",1) == -1) _exit(0); }
 void zerodie() { zero(); substdio_flush(subfdoutsmall); _exit(0); }
@@ -99,6 +110,9 @@ void dropped() {
   outhost();
   out(" but connection died. ");
   if (flagcritical) out("Possible duplicate! ");
+#ifdef TLS
+  if (ssl_err_str) { out((char *)ssl_err_str); out(" "); }
+#endif
   out("(#4.4.2)\n");
   zerodie();
 }
@@ -110,6 +124,12 @@ int timeout = 1200;
 int saferead(fd,buf,len) int fd; char *buf; int len;
 {
   int r;
+#ifdef TLS
+  if (ssl) {
+    r = ssl_timeoutread(timeout, smtpfd, smtpfd, ssl, buf, len);
+    if (r < 0) ssl_err_str = ssl_error_str();
+  } else
+#endif
   r = timeoutread(timeout,smtpfd,buf,len);
   if (r <= 0) dropped();
   return r;
@@ -117,6 +137,12 @@ int saferead(fd,buf,len) int fd; char *b
 int safewrite(fd,buf,len) int fd; char *buf; int len;
 {
   int r;
+#ifdef TLS
+  if (ssl) {
+    r = ssl_timeoutwrite(timeout, smtpfd, smtpfd, ssl, buf, len);
+    if (r < 0) ssl_err_str = ssl_error_str();
+  } else
+#endif 
   r = timeoutwrite(timeout,smtpfd,buf,len);
   if (r <= 0) dropped();
   return r;
@@ -194,19 +220,25 @@ unsigned long ehlo()
   e = smtptext.s + smtptext.len - 6; /* 250-?\n */
   while (s <= e)
   {
+    int wasspace = 0;
+
     if (!saa_readyplus(&ehlokw, 1)) temp_nomem();
     sa = ehlokw.sa + ehlokw.len++;
     if (ehlokw.len > maxehlokwlen) *sa = sauninit; else sa->len = 0;
 
-    /* smtptext is known to end in a '\n' */
-    for (p = (s += 4); ; ++p)
-      if (*p == '\n' || *p == ' ' || *p == '\t') {
-        if (!stralloc_catb(sa, s, p - s) || !stralloc_0(sa)) temp_nomem();
-        if (*p++ == '\n') break;
-        while (*p == ' ' || *p == '\t') ;
-        s = p;
-      }
-    s = p;
+     /* smtptext is known to end in a '\n' */
+     for (p = (s += 4); ; ++p)
+       if (*p == '\n' || *p == ' ' || *p == '\t') {
+         if (!wasspace)
+           if (!stralloc_catb(sa, s, p - s) || !stralloc_0(sa)) temp_nomem();
+         if (*p == '\n') break;
+         wasspace = 1;
+       } else if (wasspace == 1) {
+         wasspace = 0;
+         s = p;
+       }
+    s = ++p;
+
     /* keyword should consist of alpha-num and '-'
      * broken AUTH might use '=' instead of space */
     for (p = sa->s; *p; ++p) if (*p == '=') { *p = 0; break; }
@@ -232,6 +264,17 @@ void quit(prepend,append)
 char *prepend;
 char *append;
 {
+#ifdef TLS
+  /* shouldn't talk to the client unless in an appropriate state */
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+  OSSL_HANDSHAKE_STATE state = ssl ? SSL_get_state(ssl) : TLS_ST_BEFORE;
+  if (state & TLS_ST_OK || (!smtps && state & TLS_ST_BEFORE))
+  
+#else
+  int state = ssl ? ssl->state : SSL_ST_BEFORE;
+  if (state & SSL_ST_OK || (!smtps && state & SSL_ST_BEFORE))
+#endif
+#endif
   substdio_putsflush(&smtpto,"QUIT\r\n");
   /* waiting for remote side is just too ridiculous */
   out(prepend);
@@ -239,6 +282,30 @@ char *append;
   out(append);
   out(".\n");
   outsmtptext();
+
+#if defined(TLS) && defined(DEBUG)
+  if (ssl) {
+    X509 *peercert;
+
+    out("STARTTLS proto="); out(SSL_get_version(ssl));
+    out("; cipher="); out(SSL_get_cipher(ssl));
+
+    /* we want certificate details */
+    if (peercert = SSL_get_peer_certificate(ssl)) {
+      char *str;
+
+      str = X509_NAME_oneline(X509_get_subject_name(peercert), NULL, 0);
+      out("; subject="); out(str); OPENSSL_free(str);
+
+      str = X509_NAME_oneline(X509_get_issuer_name(peercert), NULL, 0);
+      out("; issuer="); out(str); OPENSSL_free(str);
+
+      X509_free(peercert);
+    }
+    out(";\n");
+  }
+#endif
+
   zerodie();
 }
 
@@ -267,6 +334,206 @@ void blast()
   substdio_flush(&smtpto);
 }
 
+#ifdef TLS
+char *partner_fqdn = 0;
+
+# define TLS_QUIT quit(ssl ? "; connected to " : "; connecting to ", "")
+void tls_quit(const char *s1, const char *s2)
+{
+  out((char *)s1); if (s2) { out(": "); out((char *)s2); } TLS_QUIT;
+}
+# define tls_quit_error(s) tls_quit(s, ssl_error())
+
+int match_partner(const char *s, int len)
+{
+  if (!case_diffb(partner_fqdn, len, s) && !partner_fqdn[len]) return 1;
+  /* we also match if the name is *.domainname */
+  if (*s == '*') {
+    const char *domain = partner_fqdn + str_chr(partner_fqdn, '.');
+    if (!case_diffb(domain, --len, ++s) && !domain[len]) return 1;
+  }
+  return 0;
+}
+
+/* don't want to fail handshake if certificate can't be verified */
+int verify_cb(int preverify_ok, X509_STORE_CTX *ctx) { return 1; }
+
+int tls_init()
+{
+  int i;
+  SSL *myssl;
+  SSL_CTX *ctx;
+  stralloc saciphers = {0};
+  const char *ciphers, *servercert = 0;
+
+  if (partner_fqdn) {
+    struct stat st;
+    stralloc tmp = {0};
+    if (!stralloc_copys(&tmp, "control/tlshosts/")
+      || !stralloc_catb(&tmp, partner_fqdn, str_len(partner_fqdn))
+      || !stralloc_catb(&tmp, ".pem", 5)) temp_nomem();
+    if (stat(tmp.s, &st) == 0) 
+      servercert = tmp.s;
+    else {
+      if (!stralloc_copys(&tmp, "control/notlshosts/")
+        || !stralloc_catb(&tmp, partner_fqdn, str_len(partner_fqdn)+1))
+        temp_nomem();
+      if ((stat("control/tlshosts/exhaustivelist", &st) == 0) ||
+	  (stat(tmp.s, &st) == 0)) {
+         alloc_free(tmp.s);
+         return 0;
+      }
+      alloc_free(tmp.s);
+    }
+  }
+ 
+  if (!smtps) {
+    stralloc *sa = ehlokw.sa;
+    unsigned int len = ehlokw.len;
+    /* look for STARTTLS among EHLO keywords */
+    for ( ; len && case_diffs(sa->s, "STARTTLS"); ++sa, --len) ;
+    if (!len) {
+      if (!servercert) return 0;
+      out("ZNo TLS achieved while "); out((char *)servercert);
+      out(" exists"); smtptext.len = 0; TLS_QUIT;
+    }
+  }
+
+  SSL_library_init();
+  ctx = SSL_CTX_new(SSLv23_client_method());
+  if (!ctx) {
+    if (!smtps && !servercert) return 0;
+    smtptext.len = 0;
+    tls_quit_error("ZTLS error initializing ctx");
+  }
+
+  /* POODLE vulnerability */
+  SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
+
+  if (servercert) {
+    if (!SSL_CTX_load_verify_locations(ctx, servercert, NULL)) {
+      SSL_CTX_free(ctx);
+      smtptext.len = 0;
+      out("ZTLS unable to load "); tls_quit_error(servercert);
+    }
+    /* set the callback here; SSL_set_verify didn't work before 0.9.6c */
+    SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, verify_cb);
+  }
+
+  /* let the other side complain if it needs a cert and we don't have one */
+# define CLIENTCERT "control/clientcert.pem"
+  if (SSL_CTX_use_certificate_chain_file(ctx, CLIENTCERT))
+    SSL_CTX_use_RSAPrivateKey_file(ctx, CLIENTCERT, SSL_FILETYPE_PEM);
+# undef CLIENTCERT
+
+  myssl = SSL_new(ctx);
+  SSL_CTX_free(ctx);
+  if (!myssl) {
+    if (!smtps && !servercert) return 0;
+    smtptext.len = 0;
+    tls_quit_error("ZTLS error initializing ssl");
+  }
+
+  if (!smtps) substdio_putsflush(&smtpto, "STARTTLS\r\n");
+
+  /* while the server is preparing a response, do something else */
+  if (control_readfile(&saciphers, "control/tlsclientciphers", 0) == -1)
+    { SSL_free(myssl); temp_control(); }
+  if (saciphers.len) {
+    for (i = 0; i < saciphers.len - 1; ++i)
+      if (!saciphers.s[i]) saciphers.s[i] = ':';
+    ciphers = saciphers.s;
+  }
+  else ciphers = "DEFAULT";
+  SSL_set_cipher_list(myssl, ciphers);
+  alloc_free(saciphers.s);
+
+  SSL_set_fd(myssl, smtpfd);
+
+  /* read the response to STARTTLS */
+  if (!smtps) {
+    if (smtpcode() != 220) {
+      SSL_free(myssl);
+      if (!servercert) return 0;
+      out("ZSTARTTLS rejected while ");
+      out((char *)servercert); out(" exists"); TLS_QUIT;
+    }
+    smtptext.len = 0;
+  }
+
+  ssl = myssl;
+  if (ssl_timeoutconn(timeout, smtpfd, smtpfd, ssl) <= 0)
+    tls_quit("ZTLS connect failed", ssl_error_str());
+
+  if (servercert) {
+    X509 *peercert;
+    STACK_OF(GENERAL_NAME) *gens;
+    int found_gen_dns = 0;
+    int matched_gen_dns = 0;
+
+    int r = SSL_get_verify_result(ssl);
+    if (r != X509_V_OK) {
+      out("ZTLS unable to verify server with ");
+      tls_quit(servercert, X509_verify_cert_error_string(r));
+    }
+    alloc_free(servercert);
+
+    peercert = SSL_get_peer_certificate(ssl);
+    if (!peercert) {
+      out("ZTLS unable to verify server ");
+      tls_quit(partner_fqdn, "no certificate provided");
+    }
+
+    /* RFC 2595 section 2.4: find a matching name
+     * first find a match among alternative names */
+    gens = X509_get_ext_d2i(peercert, NID_subject_alt_name, 0, 0);
+    if (gens) {
+      for (i = 0, r = sk_GENERAL_NAME_num(gens); i < r; ++i)
+      {
+        const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, i);
+        if (gn->type == GEN_DNS){
+          found_gen_dns = 1;
+          if (match_partner(gn->d.ia5->data, gn->d.ia5->length)){
+            matched_gen_dns = 1;
+            break;
+          }
+        }
+      }
+      sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
+    }
+
+    /* no SubjectAltName of type DNS found, look up commonName */
+    if (!found_gen_dns) {
+      stralloc peer = {0};
+      X509_NAME *subj = X509_get_subject_name(peercert);
+      i = X509_NAME_get_index_by_NID(subj, NID_commonName, -1);
+      if (i >= 0) {
+        const ASN1_STRING *s = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(subj, i));
+        if (s) { peer.len = s->length; peer.s = s->data; }
+      }
+      if (peer.len <= 0) {
+        out("ZTLS unable to verify server ");
+        tls_quit(partner_fqdn, "certificate contains no valid commonName");
+      }
+      if (!match_partner(peer.s, peer.len)) {
+        out("ZTLS unable to verify server "); out(partner_fqdn);
+        out(": received certificate for "); outsafe(&peer); TLS_QUIT;
+      }
+    } else if (!matched_gen_dns) {
+      out("ZTLS unable to verify server ");
+      tls_quit(partner_fqdn, "certificate contains no matching dNSNnames");
+    }
+
+    X509_free(peercert);
+  }
+
+  if (smtps) if (smtpcode() != 220)
+    quit("ZTLS Connected to "," but greeting failed");
+
+  return 1;
+}
+#endif
+
 stralloc recip = {0};
 
 void smtp()
@@ -274,12 +541,37 @@ void smtp()
   unsigned long code;
   int flagbother;
   int i;
+
+#ifndef PORT_SMTP
+  /* the qmtpc patch uses smtp_port and undefines PORT_SMTP */
+# define port smtp_port
+#endif
+
+#ifdef TLS
+# ifdef MXPS
+  if (type == 'S') smtps = 1;
+  else if (type != 's')
+# endif
+    if (port == 465) smtps = 1;
+  if (!smtps)
+#endif
  
   if (smtpcode() != 220) quit("ZConnected to "," but greeting failed");
  
 #ifdef EHLO
+# ifdef TLS
+  if (!smtps)
+# endif
   code = ehlo();
 
+# ifdef TLS
+  if (tls_init())
+    /* RFC2487 says we should issue EHLO (even if we might not need
+     * extensions); at the same time, it does not prohibit a server
+     * to reject the EHLO and make us fallback to HELO */
+    code = ehlo();
+# endif
+
   if (code == 250) {
     /* add EHLO response checks here */
 
@@ -484,6 +776,9 @@ char **argv;
     if (timeoutconn(smtpfd,&ip.ix[i].ip,(unsigned int) port,timeoutconnect) == 0) {
       tcpto_err(&ip.ix[i].ip,0);
       partner = ip.ix[i].ip;
+#ifdef TLS
+      partner_fqdn = ip.ix[i].fqdn;
+#endif
       smtp(); /* does not return */
     }
     tcpto_err(&ip.ix[i].ip,errno == error_timeout);
--- netqmail-1.06-orig/qmail-remote.8	1998-06-15 10:53:16.000000000 +0000
+++ netqmail-1.06/qmail-remote.8	2015-12-01 15:54:59.029940779 +0000
@@ -114,6 +114,10 @@ arguments.
 always exits zero.
 .SH "CONTROL FILES"
 .TP 5
+.I clientcert.pem
+SSL certificate that is used to authenticate with the remote server
+during a TLS session.
+.TP 5
 .I helohost
 Current host name,
 for use solely in saying hello to the remote SMTP server.
@@ -123,6 +127,16 @@ if that is supplied;
 otherwise
 .B qmail-remote
 refuses to run.
+
+.TP 5
+.I notlshosts/<FQDN>
+.B qmail-remote
+will not try TLS on servers for which this file exists
+.RB ( <FQDN>
+is the fully-qualified domain name of the server). 
+.IR (tlshosts/<FQDN>.pem 
+takes precedence over this file however).
+
 .TP 5
 .I smtproutes
 Artificial SMTP routes.
@@ -156,6 +170,8 @@ may be empty;
 this tells
 .B qmail-remote
 to look up MX records as usual.
+.I port 
+value of 465 (deprecated smtps port) causes TLS session to be started.
 .I smtproutes
 may include wildcards:
 
@@ -195,6 +211,33 @@ Number of seconds
 .B qmail-remote
 will wait for each response from the remote SMTP server.
 Default: 1200.
+
+.TP 5
+.I tlsclientciphers
+A set of OpenSSL client cipher strings. Multiple ciphers
+contained in a string should be separated by a colon.
+
+.TP 5
+.I tlshosts/<FQDN>.pem
+.B qmail-remote
+requires TLS authentication from servers for which this file exists
+.RB ( <FQDN>
+is the fully-qualified domain name of the server). One of the
+.I dNSName
+or the
+.I CommonName
+attributes have to match. The file contains the trusted CA certificates.
+
+.B WARNING:
+this option may cause mail to be delayed, bounced, doublebounced, or lost.
+
+.TP 5
+.I tlshosts/exhaustivelist
+if this file exists
+no TLS will be tried on hosts other than those for which a file
+.B tlshosts/<FQDN>.pem
+exists.
+
 .SH "SEE ALSO"
 addresses(5),
 envelopes(5),
--- netqmail-1.06-orig/qmail-control.9	1998-06-15 10:53:16.000000000 +0000
+++ netqmail-1.06/qmail-control.9	2015-12-08 00:33:06.248714330 +0000
@@ -43,11 +43,14 @@ control	default	used by
 .I badmailfrom	\fR(none)	\fRqmail-smtpd
 .I bouncefrom	\fRMAILER-DAEMON	\fRqmail-send
 .I bouncehost	\fIme	\fRqmail-send
+.I clientca.pem	\fR(none)	\fRqmail-smtpd
+.I clientcert.pem	\fR(none)	\fRqmail-remote
 .I concurrencylocal	\fR10	\fRqmail-send
 .I concurrencyremote	\fR20	\fRqmail-send
 .I defaultdomain	\fIme	\fRqmail-inject
 .I defaulthost	\fIme	\fRqmail-inject
 .I databytes	\fR0	\fRqmail-smtpd
+.I dh2048.pem	\fR(none)	\fRqmail-smtpd
 .I doublebouncehost	\fIme	\fRqmail-send
 .I doublebounceto	\fRpostmaster	\fRqmail-send
 .I envnoathost	\fIme	\fRqmail-send
@@ -61,11 +64,17 @@ control	default	used by
 .I qmqpservers	\fR(none)	\fRqmail-qmqpc
 .I queuelifetime	\fR604800	\fRqmail-send
 .I rcpthosts	\fR(none)	\fRqmail-smtpd
+.I rsa2048.pem	\fR(none)	\fRqmail-smtpd
+.I servercert.pem	\fR(none)	\fRqmail-smtpd
 .I smtpgreeting	\fIme	\fRqmail-smtpd
 .I smtproutes	\fR(none)	\fRqmail-remote
 .I timeoutconnect	\fR60	\fRqmail-remote
 .I timeoutremote	\fR1200	\fRqmail-remote
 .I timeoutsmtpd	\fR1200	\fRqmail-smtpd
+.I tlsclients	\fR(none)	\fRqmail-smtpd
+.I tlsclientciphers	\fR(none)	\fRqmail-remote
+.I tlshosts/FQDN.pem	\fR(none)	\fRqmail-remote
+.I tlsserverciphers	\fR(none)	\fRqmail-smtpd
 .I virtualdomains	\fR(none)	\fRqmail-send
 .fi
 .RE
--- netqmail-1.06-orig/dns.c	2007-11-30 20:22:54.000000000 +0000
+++ netqmail-1.06/dns.c	2019-04-08 15:22:04.390598941 +0000
@@ -267,12 +267,14 @@ stralloc *sa;
 int pref;
 {
  int r;
- struct ip_mx ix;
+ struct ip_mx ix = {0};
 
  if (!stralloc_copy(&glue,sa)) return DNS_MEM;
  if (!stralloc_0(&glue)) return DNS_MEM;
  if (glue.s[0]) {
+#ifndef IX_FQDN
    ix.pref = 0;
+#endif
    if (!glue.s[ip_scan(glue.s,&ix.ip)] || !glue.s[ip_scanbracket(glue.s,&ix.ip)])
     {
      if (!ipalloc_append(ia,&ix)) return DNS_MEM;
@@ -291,9 +293,16 @@ int pref;
    ix.ip = ip;
    ix.pref = pref;
    if (r == DNS_SOFT) return DNS_SOFT;
-   if (r == 1)
+   if (r == 1) {
+#ifdef IX_FQDN
+     ix.fqdn = glue.s;
+#endif
      if (!ipalloc_append(ia,&ix)) return DNS_MEM;
   }
+  }
+#ifdef IX_FQDN
+ glue.s = 0;
+#endif
  return 0;
 }
 
@@ -313,7 +322,7 @@ unsigned long random;
 {
  int r;
  struct mx { stralloc sa; unsigned short p; } *mx;
- struct ip_mx ix;
+ struct ip_mx ix = {0};
  int nummx;
  int i;
  int j;
@@ -325,7 +334,9 @@ unsigned long random;
  if (!stralloc_copy(&glue,sa)) return DNS_MEM;
  if (!stralloc_0(&glue)) return DNS_MEM;
  if (glue.s[0]) {
+#ifndef IX_FQDN
    ix.pref = 0;
+#endif
    if (!glue.s[ip_scan(glue.s,&ix.ip)] || !glue.s[ip_scanbracket(glue.s,&ix.ip)])
     {
      if (!ipalloc_append(ia,&ix)) return DNS_MEM;
--- netqmail-1.06-orig/hier.c	1998-06-15 10:53:16.000000000 +0000
+++ netqmail-1.06/hier.c	2015-12-01 15:54:59.033940812 +0000
@@ -143,6 +143,9 @@ void hier()
   c(auto_qmail,"bin","qail",auto_uido,auto_gidq,0755);
   c(auto_qmail,"bin","elq",auto_uido,auto_gidq,0755);
   c(auto_qmail,"bin","pinq",auto_uido,auto_gidq,0755);
+#ifdef TLS
+  c(auto_qmail,"bin","update_tmprsadh",auto_uido,auto_gidq,0755);
+#endif
 
   c(auto_qmail,"man/man5","addresses.5",auto_uido,auto_gidq,0644);
   c(auto_qmail,"man/cat5","addresses.0",auto_uido,auto_gidq,0644);
--- netqmail-1.06-orig/ipalloc.h	1998-06-15 10:53:16.000000000 +0000
+++ netqmail-1.06/ipalloc.h	2015-12-01 15:54:59.033940812 +0000
@@ -3,7 +3,15 @@
 
 #include "ip.h"
 
+#ifdef TLS
+# define IX_FQDN 1
+#endif
+
+#ifdef IX_FQDN
+struct ip_mx { struct ip_address ip; int pref; char *fqdn; } ;
+#else
 struct ip_mx { struct ip_address ip; int pref; } ;
+#endif
 
 #include "gen_alloc.h"
 
--- netqmail-1.06-orig/tls.c	2019-04-08 15:26:13.112123436 +0000
+++ netqmail-1.06/tls.c	2019-04-08 15:17:31.924930725 +0000
@@ -0,0 +1,27 @@
+#ifdef TLS
+#include "exit.h"
+#include "error.h"
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+
+int smtps = 0;
+SSL *ssl = NULL;
+
+void ssl_free(SSL *myssl) { SSL_shutdown(myssl); SSL_free(myssl); }
+void ssl_exit(int status) { if (ssl) ssl_free(ssl); _exit(status); }
+
+const char *ssl_error()
+{
+  int r = ERR_get_error();
+  if (!r) return NULL;
+  SSL_load_error_strings();
+  return ERR_error_string(r, NULL);
+}
+const char *ssl_error_str()
+{
+  const char *err = ssl_error();
+  if (err) return err;
+  if (!errno) return 0;
+  return (errno == error_timeout) ? "timed out" : error_str(errno);
+}
+#endif
--- netqmail-1.06-orig/tls.h	2019-04-08 15:26:13.112123436 +0000
+++ netqmail-1.06/tls.h	2015-12-01 15:54:59.033940812 +0000
@@ -0,0 +1,16 @@
+#ifndef TLS_H
+#define TLS_H
+
+#include <openssl/ssl.h>
+
+extern int smtps;
+extern SSL *ssl;
+
+void ssl_free(SSL *myssl);
+void ssl_exit(int status);
+# define _exit ssl_exit
+
+const char *ssl_error();
+const char *ssl_error_str();
+
+#endif
--- netqmail-1.06-orig/ssl_timeoutio.c	2019-04-08 15:26:13.112123436 +0000
+++ netqmail-1.06/ssl_timeoutio.c	2019-04-08 15:17:14.324823036 +0000
@@ -0,0 +1,114 @@
+#ifdef TLS
+#include "select.h"
+#include "error.h"
+#include "ndelay.h"
+#include "now.h"
+#include "ssl_timeoutio.h"
+
+int ssl_timeoutio(int (*fun)(),
+  int t, int rfd, int wfd, SSL *ssl, char *buf, int len)
+{
+  int n;
+  const datetime_sec end = (datetime_sec)t + now();
+
+  do {
+    fd_set fds;
+    struct timeval tv;
+
+    const int r = buf ? fun(ssl, buf, len) : fun(ssl);
+    if (r > 0) return r;
+
+    t = end - now();
+    if (t < 0) break;
+    tv.tv_sec = (time_t)t; tv.tv_usec = 0;
+
+    FD_ZERO(&fds);
+    switch (SSL_get_error(ssl, r))
+    {
+    default: return r; /* some other error */
+    case SSL_ERROR_WANT_READ:
+      FD_SET(rfd, &fds); n = select(rfd + 1, &fds, NULL, NULL, &tv);
+      break;
+    case SSL_ERROR_WANT_WRITE:
+      FD_SET(wfd, &fds); n = select(wfd + 1, NULL, &fds, NULL, &tv);
+      break;
+    }
+
+    /* n is the number of descriptors that changed status */
+  } while (n > 0);
+
+  if (n != -1) errno = error_timeout;
+  return -1;
+}
+
+int ssl_timeoutaccept(int t, int rfd, int wfd, SSL *ssl)
+{
+  int r;
+
+  /* if connection is established, keep NDELAY */
+  if (ndelay_on(rfd) == -1 || ndelay_on(wfd) == -1) return -1;
+  r = ssl_timeoutio(SSL_accept, t, rfd, wfd, ssl, NULL, 0);
+
+  if (r <= 0) { ndelay_off(rfd); ndelay_off(wfd); }
+  else SSL_set_mode(ssl, SSL_MODE_ENABLE_PARTIAL_WRITE);
+
+  return r;
+}
+
+int ssl_timeoutconn(int t, int rfd, int wfd, SSL *ssl)
+{
+  int r;
+
+  /* if connection is established, keep NDELAY */
+  if (ndelay_on(rfd) == -1 || ndelay_on(wfd) == -1) return -1;
+  r = ssl_timeoutio(SSL_connect, t, rfd, wfd, ssl, NULL, 0);
+
+  if (r <= 0) { ndelay_off(rfd); ndelay_off(wfd); }
+  else SSL_set_mode(ssl, SSL_MODE_ENABLE_PARTIAL_WRITE);
+
+  return r;
+}
+
+int ssl_timeoutrehandshake(int t, int rfd, int wfd, SSL *ssl)
+{
+  int r=0;
+
+  SSL_renegotiate(ssl);
+
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+  char buf[1]; /* dummy read buffer */
+  struct timeval tv;
+  fd_set fds;
+  r = ssl_timeoutio(SSL_do_handshake, t, rfd, wfd, ssl, NULL, 0);
+  if (r <=0) return r;
+
+  tv.tv_sec = (time_t)t; tv.tv_usec = 0;
+  FD_ZERO(&fds);  FD_SET(rfd, &fds);
+  if ((r = select(rfd + 1, &fds, NULL, NULL, &tv)>0) && FD_ISSET(rfd, &fds)){
+    r = SSL_read(ssl, buf, 1);
+    if (SSL_get_error(ssl, r) == SSL_ERROR_WANT_READ) r = 1; /*ignore */
+  }
+  if (r <=0) return r;
+#else
+  r = ssl_timeoutio(SSL_do_handshake, t, rfd, wfd, ssl, NULL, 0);
+  if (r <= 0 || ssl->type == SSL_ST_CONNECT) return r;
+
+  /* this is for the server only */
+  ssl->state = SSL_ST_ACCEPT;
+#endif
+  return ssl_timeoutio(SSL_do_handshake, t, rfd, wfd, ssl, NULL, 0);
+}
+
+int ssl_timeoutread(int t, int rfd, int wfd, SSL *ssl, char *buf, int len)
+{
+  if (!buf) return 0;
+  if (SSL_pending(ssl)) return SSL_read(ssl, buf, len);
+  return ssl_timeoutio(SSL_read, t, rfd, wfd, ssl, buf, len);
+}
+
+int ssl_timeoutwrite(int t, int rfd, int wfd, SSL *ssl, char *buf, int len)
+{
+  if (!buf) return 0;
+  return ssl_timeoutio(SSL_write, t, rfd, wfd, ssl, buf, len);
+}
+#endif
--- netqmail-1.06-orig/ssl_timeoutio.h	2019-04-08 15:26:13.112123436 +0000
+++ netqmail-1.06/ssl_timeoutio.h	2019-03-22 21:11:16.610440636 +0000
@@ -0,0 +1,21 @@
+#ifndef SSL_TIMEOUTIO_H
+#define SSL_TIMEOUTIO_H
+
+#include <openssl/ssl.h>
+
+/* the version is like this: 0xMNNFFPPS: major minor fix patch status */
+#if OPENSSL_VERSION_NUMBER < 0x00908000L
+# error "Need OpenSSL version at least 0.9.8"
+#endif
+
+int ssl_timeoutconn(int t, int rfd, int wfd, SSL *ssl);
+int ssl_timeoutaccept(int t, int rfd, int wfd, SSL *ssl);
+int ssl_timeoutrehandshake(int t, int rfd, int wfd, SSL *ssl);
+
+int ssl_timeoutread(int t, int rfd, int wfd, SSL *ssl, char *buf, int len);
+int ssl_timeoutwrite(int t, int rfd, int wfd, SSL *ssl, char *buf, int len);
+
+int ssl_timeoutio(
+  int (*fun)(), int t, int rfd, int wfd, SSL *ssl, char *buf, int len);
+
+#endif
--- netqmail-1.06-orig/TARGETS	1998-06-15 10:53:16.000000000 +0000
+++ netqmail-1.06/TARGETS	2015-12-01 15:54:59.033940812 +0000
@@ -168,6 +168,8 @@ control.o
 constmap.o
 timeoutread.o
 timeoutwrite.o
+tls.o
+ssl_timeoutio.o
 timeoutconn.o
 tcpto.o
 dns.o
@@ -320,6 +322,7 @@ binm2
 binm2+df
 binm3
 binm3+df
+Makefile-cert
 it
 qmail-local.0
 qmail-lspawn.0
@@ -385,3 +388,4 @@ forgeries.0
 man
 setup
 check
+update_tmprsadh
--- netqmail-1.06-orig/Makefile-cert.mk	2019-04-08 15:26:13.112123436 +0000
+++ netqmail-1.06/Makefile-cert.mk	2015-12-01 15:54:59.033940812 +0000
@@ -0,0 +1,21 @@
+cert-req: req.pem
+cert cert-req: QMAIL/control/clientcert.pem
+	@:
+
+QMAIL/control/clientcert.pem: QMAIL/control/servercert.pem
+	ln -s $< $@
+
+QMAIL/control/servercert.pem:
+	PATH=$$PATH:/usr/local/ssl/bin \
+		openssl req -new -x509 -nodes -days 366 -out $@ -keyout $@
+	chmod 640 $@
+	chown `head -2 conf-users | tail -1`:`head -1 conf-groups` $@
+
+req.pem:
+	PATH=$$PATH:/usr/local/ssl/bin openssl req \
+		-new -nodes -out $@ -keyout QMAIL/control/servercert.pem
+	chmod 640 QMAIL/control/servercert.pem
+	chown `head -2 conf-users | tail -1`:`head -1 conf-groups` QMAIL/control/servercert.pem
+	@echo
+	@echo "Send req.pem to your CA to obtain signed_req.pem, and do:"
+	@echo "cat signed_req.pem >> QMAIL/control/servercert.pem"
--- netqmail-1.06-orig/conf-cc	1998-06-15 10:53:16.000000000 +0000
+++ netqmail-1.06/conf-cc	2019-04-08 15:25:56.312020413 +0000
@@ -1,3 +1,3 @@
-cc -O2
+cc -O2 -DTLS=20190517 -I/usr/local/ssl/include
 
 This will be used to compile .c files.
--- netqmail-1.06-orig/Makefile	2007-11-30 20:22:54.000000000 +0000
+++ netqmail-1.06/Makefile	2015-12-01 15:54:59.033940812 +0000
@@ -808,7 +808,7 @@ dnsptr dnsip dnsmxip dnsfq hostname ipme
 forward preline condredirect bouncesaying except maildirmake \
 maildir2mbox maildirwatch qail elq pinq idedit install-big install \
 instcheck home home+df proc proc+df binm1 binm1+df binm2 binm2+df \
-binm3 binm3+df
+binm3 binm3+df update_tmprsadh
 
 load: \
 make-load warn-auto.sh systype
@@ -1444,6 +1444,7 @@ ndelay.a case.a sig.a open.a lock.a seek
 substdio.a error.a str.a fs.a auto_qmail.o dns.lib socket.lib
 	./load qmail-remote control.o constmap.o timeoutread.o \
 	timeoutwrite.o timeoutconn.o tcpto.o now.o dns.o ip.o \
+	tls.o ssl_timeoutio.o -L/usr/local/ssl/lib -lssl -lcrypto \
 	ipalloc.o ipme.o quote.o ndelay.a case.a sig.a open.a \
 	lock.a seek.a getln.a stralloc.a alloc.a substdio.a error.a \
 	str.a fs.a auto_qmail.o  `cat dns.lib` `cat socket.lib`
@@ -1539,6 +1540,7 @@ open.a sig.a case.a env.a stralloc.a all
 fs.a auto_qmail.o socket.lib
 	./load qmail-smtpd rcpthosts.o commands.o timeoutread.o \
 	timeoutwrite.o ip.o ipme.o ipalloc.o control.o constmap.o \
+	tls.o ssl_timeoutio.o ndelay.a -L/usr/local/ssl/lib -lssl -lcrypto \
 	received.o date822fmt.o now.o qmail.o cdb.a fd.a wait.a \
 	datetime.a getln.a open.a sig.a case.a env.a stralloc.a \
 	alloc.a substdio.a error.a str.a fs.a auto_qmail.o  `cat \
@@ -1827,7 +1829,8 @@ date822fmt.h date822fmt.c dns.h dns.c tr
 ipalloc.h ipalloc.c select.h1 select.h2 trysysel.c ndelay.h ndelay.c \
 ndelay_off.c direntry.3 direntry.h1 direntry.h2 trydrent.c prot.h \
 prot.c chkshsgr.c warn-shsgr tryshsgr.c ipme.h ipme.c trysalen.c \
-maildir.5 maildir.h maildir.c tcp-environ.5 constmap.h constmap.c
+maildir.5 maildir.h maildir.c tcp-environ.5 constmap.h constmap.c \
+update_tmprsadh
 	shar -m `cat FILES` > shar
 	chmod 400 shar
 
@@ -2108,6 +2111,19 @@ timeoutwrite.o: \
 compile timeoutwrite.c timeoutwrite.h select.h error.h readwrite.h
 	./compile timeoutwrite.c
 
+qmail-smtpd: tls.o ssl_timeoutio.o ndelay.a
+qmail-remote: tls.o ssl_timeoutio.o
+qmail-smtpd.o: tls.h ssl_timeoutio.h
+qmail-remote.o: tls.h ssl_timeoutio.h
+
+tls.o: \
+compile tls.c exit.h error.h
+	./compile tls.c
+
+ssl_timeoutio.o: \
+compile ssl_timeoutio.c ssl_timeoutio.h select.h error.h ndelay.h
+	./compile ssl_timeoutio.c
+
 token822.o: \
 compile token822.c stralloc.h gen_alloc.h alloc.h str.h token822.h \
 gen_alloc.h gen_allocdefs.h
@@ -2139,3 +2155,26 @@ compile wait_nohang.c haswaitp.h
 wait_pid.o: \
 compile wait_pid.c error.h haswaitp.h
 	./compile wait_pid.c
+
+cert cert-req: \
+Makefile-cert
+	@$(MAKE) -sf $< $@
+
+Makefile-cert: \
+conf-qmail conf-users conf-groups Makefile-cert.mk
+	@cat Makefile-cert.mk \
+	| sed s}QMAIL}"`head -1 conf-qmail`"}g \
+	> $@
+
+update_tmprsadh: \
+conf-qmail conf-users conf-groups update_tmprsadh.sh
+	@cat update_tmprsadh.sh\
+	| sed s}UGQMAILD}"`head -2 conf-users|tail -1`:`head -1 conf-groups`"}g \
+	| sed s}QMAIL}"`head -1 conf-qmail`"}g \
+	> $@
+	chmod 755 update_tmprsadh 
+
+tmprsadh: \
+update_tmprsadh
+	echo "Creating new temporary RSA and DH parameters"
+	./update_tmprsadh
--- netqmail-1.06-orig/update_tmprsadh.sh	2019-04-08 15:26:13.112123436 +0000
+++ netqmail-1.06/update_tmprsadh.sh	2015-12-08 00:32:33.936474103 +0000
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# Update temporary RSA and DH keys
+# Frederik Vermeulen 2004-05-31 GPL
+
+umask 0077 || exit 0
+
+export PATH="$PATH:/usr/local/bin/ssl:/usr/sbin"
+
+openssl genrsa -out QMAIL/control/rsa2048.new 2048 &&
+chmod 600 QMAIL/control/rsa2048.new &&
+chown UGQMAILD QMAIL/control/rsa2048.new &&
+mv -f QMAIL/control/rsa2048.new QMAIL/control/rsa2048.pem
+echo
+
+openssl dhparam -2 -out QMAIL/control/dh2048.new 2048 &&
+chmod 600 QMAIL/control/dh2048.new &&
+chown UGQMAILD QMAIL/control/dh2048.new &&
+mv -f QMAIL/control/dh2048.new QMAIL/control/dh2048.pem