Make qmail openssl 3.0 compatible

- remove support for loading custom DH params from pem.
  use opensslconf if really required
- remove support for loading custom ec group from params
- reimplement DANE support using openssl DANE functions

3 files changed, 130 insertions, 282 deletions

diff --git a/Makefile b/Makefile
index 5f0c0f6..5bd3765 100644
--- a/Makefile
+++ b/Makefile
@@ -1533,7 +1533,7 @@ dns.lib socket.lib
         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 \
         env.a str.a fs.a auto_qmail.o base64.o \
-        `cat dns.lib` `cat socket.lib` -lval -lsres -lidn2
+        `cat dns.lib` `cat socket.lib` -lidn2
 
 qmail-remote.0: \
 qmail-remote.8
diff --git a/qmail-remote.c b/qmail-remote.c
index 0e2377e..1a09df9 100644
--- a/qmail-remote.c
+++ b/qmail-remote.c
@@ -63,8 +63,6 @@ struct ip_address partner;
 # include "tls.h"
 # include "ssl_timeoutio.h"
 # include <openssl/x509v3.h>
-# include <validator/validator.h>
-# include <validator/val_dane.h>
 
 # define EHLO 1
 # define CLIENTCERT "control/clientcert.pem"
@@ -72,10 +70,6 @@ struct ip_address partner;
 int tls_init();
 const char *ssl_err_str = 0;
 char **myargv;
-val_context_t *dane_context = NULL;
-int dane_context_failed = 0;
-struct val_danestatus *dane_status = NULL;
-struct val_ssl_data *dane_ssl_data = NULL;
 #endif
 
 #ifdef SMTPUTF8
@@ -241,10 +235,6 @@ unsigned long ehlo()
   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");
@@ -437,34 +427,28 @@ int tls_init()
     }
   }
 
-  /* DANE: starts here */
-  int dane_retval = VAL_DANE_INTERNAL_ERROR;
+  /* DANE: lookup TLSA records */
   int tls_required = (smtps || servercert != NULL);
-
-  if (partner_fqdn && !servercert && !dane_context_failed) {
-    if (dane_context == NULL && val_create_context(NULL, &dane_context)
-        != VAL_NO_ERROR) {
-      dane_context_failed = 1;
-      out("lUnable to initialize libval context\n");
-      zeroflush();
+  stralloc tlsa_rr = { 0 };
+
+  if (partner_fqdn && !servercert) {
+    stralloc tlsa_label = { 0 };
+    char port[FMT_ULONG];
+
+    if (!stralloc_copyb(&tlsa_label, "_", 1)) temp_nomem();
+    port[fmt_ulong(port, smtp_port)] = 0;
+    if (!stralloc_cats(&tlsa_label, port)) temp_nomem();
+    if (!stralloc_cats(&tlsa_label, "._tcp.")) temp_nomem();
+    if (!stralloc_cats(&tlsa_label, partner_fqdn)) temp_nomem();
+
+    switch (dns_tlsa(&tlsa_rr, &tlsa_label)) {
+      case DNS_MEM: temp_nomem();
+      case DNS_SOFT: temp_dns();
+      case DNS_HARD: tlsa_rr.len = 0; // no record found
     }
 
-    if (dane_context) {
-      val_free_dane(dane_status);
-      val_free_dane_ssl(dane_ssl_data);
-
-      /* DANE: lookup TLSA records */
-      struct val_daneparams dane_params = {
-        .port  = smtp_port,
-        .proto = DANE_PARAM_PROTO_TCP
-      };
-      dane_retval = val_getdaneinfo(dane_context, partner_fqdn, &dane_params, &dane_status);
-      /* work around a bug if no error but no also no records */
-      if (dane_retval == VAL_DANE_NOERROR && dane_status == NULL)
-        dane_retval = VAL_DANE_IGNORE_TLSA;
-      if (dane_retval == VAL_DANE_NOERROR)
-        tls_required = 1;
-    }
+    if (tlsa_rr.len)
+      tls_required = 1;
   }
 
   if (!smtps) {
@@ -480,13 +464,20 @@ int tls_init()
   }
 
   SSL_library_init();
-  ctx = SSL_CTX_new(SSLv23_client_method());
+  ctx = SSL_CTX_new(TLS_client_method());
   if (!ctx) {
-    if (!tls_required) return 0;
     smtptext.len = 0;
     tls_quit_error("ZTLS error initializing ctx");
   }
-  SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3);
+  SSL_CTX_set_min_proto_version(ctx, TLS1_VERSION);
+
+  /* we verify ourself below. see SSL_get_verify_result */
+  SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+
+  if (SSL_CTX_dane_enable(ctx) <= 0) {
+    smtptext.len = 0;
+    tls_quit_error("ZTLS error initializing dane ctx");
+  }
 
   if (servercert) {
     if (!SSL_CTX_load_verify_locations(ctx, servercert, NULL)) {
@@ -497,19 +488,6 @@ int tls_init()
     /* set the callback here; SSL_set_verify didn't work before 0.9.6c */
     SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER, verify_cb);
   }
-  else if (dane_retval == VAL_DANE_NOERROR) {
-    /* DANE: treat PKIX-EE as it were DANE-EE */
-    struct val_danestatus *dane_cur;
-    for (dane_cur = dane_status; dane_cur; dane_cur = dane_cur->next) {
-      if (dane_cur->usage == DANE_USE_SVC_CONSTRAINT)
-        dane_cur->usage = DANE_USE_DOMAIN_ISSUED;
-    }
-    /* DANE: set verify callback */
-    int err = val_enable_dane_ssl(dane_context, ctx, partner_fqdn, dane_status,
-        &dane_ssl_data);
-    if (err != VAL_NO_ERROR)
-      tls_quit("ZCould not enable dane verification", p_val_error(err));
-  }
 
   /* let the other side complain if it needs a cert and we don't have one */
   if (SSL_CTX_use_certificate_chain_file(ctx, CLIENTCERT))
@@ -518,14 +496,10 @@ int tls_init()
   myssl = SSL_new(ctx);
   SSL_CTX_free(ctx);
   if (!myssl) {
-    if (!tls_required) 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 responce, do something else */
   if (control_readfile(&saciphers, "control/tlsclientciphers", 0) == -1)
     { SSL_free(myssl); temp_control(); }
@@ -539,14 +513,15 @@ int tls_init()
   SSL_set_cipher_list(myssl, ciphers);
   alloc_free(saciphers.s);
 
-#if OPENSSL_VERSION_NUMBER >= 0x10100005L
   stralloc opensslconf = {0};
   if (control_readfile(&opensslconf, "control/opensslconf", 0) == -1)
     { SSL_free(myssl); temp_control(); }
   if (opensslconf.len) {
     SSL_CONF_CTX *cctx = SSL_CONF_CTX_new();
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_FILE);
+    /* client + server so we can share one single file */
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CLIENT);
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SHOW_ERRORS);
     SSL_CONF_CTX_set_ssl(cctx, myssl);
@@ -572,13 +547,68 @@ int tls_init()
 
     (void)SSL_CONF_CTX_finish(cctx);
   }
-#endif
 
   /* set SNI hostname */
   if (partner_fqdn)
     SSL_set_tlsext_host_name(myssl, partner_fqdn);
 
-  /* SSL_set_options(myssl, SSL_OP_NO_TLSv1); */
+  /* DANE: enable + add records */
+  if (tlsa_rr.len) {
+    if (SSL_dane_enable(myssl, partner_fqdn) <= 0) {
+      smtptext.len = 0;
+      tls_quit_error("ZTLS error enabling dane");
+    }
+    SSL_dane_set_flags(myssl, DANE_FLAG_NO_DANE_EE_NAMECHECKS);
+
+    // loop through TLSA rr
+    int pos = 0, num_usable = 0;
+    unsigned char *rr_data = (unsigned char *)tlsa_rr.s;
+    while (pos < tlsa_rr.len && tlsa_rr.len - pos > 2 + 4) // sizeof(rrlen) + min(rrdata)
+    {
+      unsigned short rrlen = (rr_data[pos] << 8) + rr_data[pos + 1];
+      pos += 2;
+      uint8_t usage    = rr_data[pos];
+      uint8_t selector = rr_data[pos + 1];
+      uint8_t mtype    = rr_data[pos + 2];
+
+      /*
+       * Opportunistic DANE TLS clients support only DANE-TA(2) or DANE-EE(3).
+       * They treat all other certificate usages, and in particular PKIX-TA(0)
+       * and PKIX-EE(1), as unusable.
+       */
+      switch (usage) {
+        default:
+        case 0: /* PKIX-TA(0) */
+        case 1: /* PKIX-EE(1) */
+          pos += rrlen;
+          continue;
+        case 2: /* DANE-TA(2) */
+        case 3: /* DANE-EE(3) */
+          break;
+      }
+
+      // rrlen includes usage+selector+mtype (3) byte. remove
+      unsigned const char *cdata = rr_data + pos + 3;
+      size_t cdlen = rrlen - 3;
+      int tlsa_added = SSL_dane_tlsa_add(myssl, usage, selector, mtype, cdata, cdlen);
+      if (tlsa_added < 0) {
+        smtptext.len = 0;
+        tls_quit_error("ZTLS error adding DANE TLSA record");
+      }
+      else if (tlsa_added > 0)
+        ++num_usable;
+
+      pos += rrlen;
+    }
+
+    // no records usable. fallback to unauthenticated TLS
+    if (num_usable == 0)
+      tlsa_rr.len = 0;
+  }
+
+  if (!smtps)
+    substdio_putsflush(&smtpto, "STARTTLS\r\n");
+
   SSL_set_fd(myssl, smtpfd);
 
   /* read the responce to STARTTLS */
@@ -593,7 +623,7 @@ int tls_init()
   }
 
   ssl = myssl;
-  if (ssl_timeoutconn(timeout, smtpfd, smtpfd, ssl) <= 0) {
+  if (ssl_timeoutconn(timeout, smtpfd, smtpfd, myssl) <= 0) {
     if (tls_required)
       tls_quit("ZTLS connect failed", ssl_error_str());
     else {
@@ -617,14 +647,14 @@ int tls_init()
     X509 *peercert;
     STACK_OF(GENERAL_NAME) *gens;
 
-    int r = SSL_get_verify_result(ssl);
+    int r = SSL_get_verify_result(myssl);
     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);
+    peercert = SSL_get_peer_certificate(myssl);
     if (!peercert) {
       out("ZTLS unable to verify server ");
       tls_quit(partner_fqdn, "no certificate provided");
@@ -651,10 +681,7 @@ int tls_init()
       if (i >= 0) {
         X509_NAME_ENTRY *entry = X509_NAME_get_entry(subj, i);
         ASN1_STRING *s = X509_NAME_ENTRY_get_data(entry);
-#if OPENSSL_VERSION_NUMBER < 0x10100005L
-#define ASN1_STRING_get0_data ASN1_STRING_data
-#endif
-        if (s) { peer.len = ASN1_STRING_length(s); peer.s = (unsigned char *)ASN1_STRING_get0_data(s); }
+        if (s) { peer.len = ASN1_STRING_length(s); peer.s = (char *)ASN1_STRING_get0_data(s); }
       }
       if (peer.len <= 0) {
         out("ZTLS unable to verify server ");
@@ -669,8 +696,8 @@ int tls_init()
     X509_free(peercert);
   }
   /* DANE: verify result */
-  else if (dane_retval == VAL_DANE_NOERROR) {
-    if (!SSL_get_peer_certificate(ssl) || SSL_get_verify_result(ssl) != X509_V_OK) {
+  else if (tlsa_rr.len) {
+    if (!SSL_get_peer_certificate(myssl) || SSL_get_verify_result(myssl) != X509_V_OK) {
       out("lNo TLSA record matched: ");
       out(partner_fqdn);
       quit2("/", NULL, 0);
@@ -746,33 +773,22 @@ void mail_without_auth()
 
 void smtp()
 {
-  unsigned long code;
+  unsigned long code = 0;
   int flagbother;
-  int i, j;
-
-#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)
+  if (smtp_port == 465) smtps = 1;
+  if (!smtps) {
 #endif
-
   code = smtpcode();
   if (code >= 500 && code < 600) quit("DConnected to "," but greeting failed");
   if (code >= 400 && code < 500) return; /* try next MX, see RFC-2821 */
   if (code != 220) quit("ZConnected to "," but greeting failed");
 
+  code = ehlo();
 #ifdef TLS
-  if (!smtps)
+  }
 #endif
-  code = ehlo();
 
 #ifdef TLS
   int tls = tls_init();
@@ -782,7 +798,7 @@ void smtp()
     ssl = NULL;
     return; /* try next MX */
   }
-  else if (tls)
+  else if (tls > 0)
     /* 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 */
@@ -803,7 +819,7 @@ void smtp()
     if (code != 250) quit("ZConnected to "," but my name was rejected");
   }
 
-  i = 0;
+  int i = 0;
   if (auth_smtp_user.len && auth_smtp_pass.len)  {
     while((i += str_chr(smtptext.s+i,'\n') + 1) &&
          (i+8 < smtptext.len) &&
@@ -854,7 +870,7 @@ void smtp()
   if (code >= 400) quit("ZConnected to "," but sender was rejected");
  
   flagbother = 0;
-  for (i = 0;i < reciplist.len;++i) {
+  for (int i = 0;i < reciplist.len;++i) {
     substdio_puts(&smtpto,"RCPT TO:<");
     substdio_put(&smtpto,reciplist.sa[i].s,reciplist.sa[i].len);
     substdio_puts(&smtpto,">\r\n");
@@ -907,7 +923,6 @@ void qmtp()
 {
   struct stat st;
   unsigned long len;
-  int len2;
   char *x;
   int i;
   int n;
@@ -1039,9 +1054,11 @@ void getcontrols()
     case -1:
       temp_control();
     case 0:
-      if (!constmap_init(&maproutes,"",0,1)) temp_nomem(); break;
+      if (!constmap_init(&maproutes,"",0,1)) temp_nomem();
+      break;
     case 1:
-      if (!constmap_init(&maproutes,routes.s,routes.len,1)) temp_nomem(); break;
+      if (!constmap_init(&maproutes,routes.s,routes.len,1)) temp_nomem();
+      break;
   }
 }
 
@@ -1074,7 +1091,7 @@ char **argv;
   relayhost = 0;
   for (i = 0;i <= host.len;++i)
     if ((i == 0) || (i == host.len) || (host.s[i] == '.'))
-      if (relayhost = constmap(&maproutes,host.s + i,host.len - i))
+      if ((relayhost = constmap(&maproutes,host.s + i,host.len - i)))
         break;
   if (relayhost && !*relayhost) relayhost = 0;
  
diff --git a/qmail-smtpd.c b/qmail-smtpd.c
index 5ea23dc..0d3b16d 100644
--- a/qmail-smtpd.c
+++ b/qmail-smtpd.c
@@ -67,8 +67,6 @@ static const stralloc *client_get_session_id();
 
 #ifdef TLS
 # include <sys/stat.h>
-# include <openssl/bn.h>
-# include <openssl/dh.h>
 # include "tls.h"
 # include "ssl_timeoutio.h"
 
@@ -208,7 +206,7 @@ int err_write() { out("454 oops, unable to write pipe and I can't auth (#4.3.0)\
 void err_authd() { out("503 you're already authenticated (#5.5.0)\r\n"); }
 void err_authmail() { out("503 no auth during mail transaction (#5.5.0)\r\n"); do_hard_errors(); }
 int err_noauth() { out("504 auth type unimplemented (#5.5.1)\r\n"); do_hard_errors(); return -1; }
-int err_noauth2() { out("503 auth not available (#5.3.3)\r\n"); do_hard_errors(); }
+int err_noauth2() { out("503 auth not available (#5.3.3)\r\n"); do_hard_errors(); return -1; }
 int err_authabrt() { out("501 auth exchange canceled (#5.0.0)\r\n"); return -1; }
 int err_input() { out("501 malformed auth input (#5.5.4)\r\n"); return -1; }
 int err_wantstarttls() { out("530 Must issue a STARTTLS command first (#5.7.0)\r\n"); return -1; };
@@ -386,7 +384,7 @@ char *arg;
   if (!stralloc_copys(&addr,"")) die_nomem();
   flagesc = 0;
   flagquoted = 0;
-  for (i = 0;ch = arg[i];++i) { /* copy arg to addr, stripping quotes */
+  for (i = 0; (ch = arg[i]); ++i) { /* copy arg to addr, stripping quotes */
     if (flagesc) {
       if (!stralloc_append(&addr,&ch)) die_nomem();
       flagesc = 0;
@@ -485,7 +483,7 @@ int bmcheck(which) int which;
     }
     if ((negate) && (x == 0)) {
       if (!stralloc_copyb(&matchedregex,bmb.s + j - 1,(i - j + 1))) die_nomem();
-      if (!stralloc_0(&matchedregex)) die_nomem();      
+      if (!stralloc_0(&matchedregex)) die_nomem();
       return 1;
     }
     if (!(negate) && (x > 0)) {
@@ -582,8 +580,6 @@ void mailfrom_auth(arg,len)
 char *arg; 
 int len;
 {
-  int j;
-
   if (!stralloc_copys(&fuser,"")) die_nomem();
   if (case_starts(arg,"<>")) { if (!stralloc_cats(&fuser,"unknown")) die_nomem(); }
   else 
@@ -610,7 +606,7 @@ void mailfrom_parms(arg) char *arg;
   int len;
 
     len = str_len(arg);
-    if (!stralloc_copys(&mfparms,"")) die_nomem;
+    if (!stralloc_copys(&mfparms,"")) die_nomem();
     i = byte_chr(arg,len,'>');
     if (i > 4 && i < len) {
       while (len) {
@@ -622,10 +618,10 @@ void mailfrom_parms(arg) char *arg;
            if (case_starts(mfparms.s,"SIZE=")) if (mailfrom_size(mfparms.s+5)) { flagsize = 1; return; }
            /* we do not support this */
            //if (case_starts(mfparms.s,"AUTH=")) mailfrom_auth(mfparms.s+5,mfparms.len-5);
-           if (!stralloc_copys(&mfparms,"")) die_nomem;
+           if (!stralloc_copys(&mfparms,"")) die_nomem();
         }
         else
-          if (!stralloc_catb(&mfparms,arg,1)) die_nomem; 
+          if (!stralloc_catb(&mfparms,arg,1)) die_nomem();
       }
     }
 }
@@ -1094,17 +1090,17 @@ int authenticate(void)
   if (authout.len > 0) {
     len = authout.len;
     arg = authout.s;
-    if (!stralloc_copys(&authparams, "")) die_nomem;
+    if (!stralloc_copys(&authparams, "")) die_nomem();
     while (len) {
       if (*arg == '\0') {
         if (case_starts(authparams.s, "USER=") && (authparams.len - 5) > 0) {
           if (!stralloc_copyb(&user, authparams.s + 5, authparams.len - 5)) die_nomem();
           if (!stralloc_0(&user)) die_nomem();
         }
-        if (!stralloc_copys(&authparams, "")) die_nomem;
+        if (!stralloc_copys(&authparams, "")) die_nomem();
       }
       else
-        if (!stralloc_catb(&authparams, arg, 1)) die_nomem;
+        if (!stralloc_catb(&authparams, arg, 1)) die_nomem();
       arg++;
       len--;
     }
@@ -1130,19 +1126,19 @@ int auth_login(arg) char *arg;
   if (tls_before_auth && !ssl) return err_wantstarttls();
 #endif
   if (*arg) {
-    if (r = b64decode(arg,str_len(arg),&user) == 1) return err_input();
+    if ((r = b64decode(arg,str_len(arg),&user)) == 1) return err_input();
   }
   else {
     out("334 VXNlcm5hbWU6\r\n"); flush();       /* Username: */
     if (authgetl() < 0) return -1;
-    if (r = b64decode(authin.s,authin.len,&user) == 1) return err_input();
+    if ((r = b64decode(authin.s,authin.len,&user)) == 1) return err_input();
   }
   if (r == -1) die_nomem();
 
   out("334 UGFzc3dvcmQ6\r\n"); flush();         /* Password: */
 
   if (authgetl() < 0) return -1;
-  if (r = b64decode(authin.s,authin.len,&pass) == 1) return err_input();
+  if ((r = b64decode(authin.s,authin.len,&pass)) == 1) return err_input();
   if (r == -1) die_nomem();
 
   if (!user.len || !pass.len) return err_input();
@@ -1157,12 +1153,12 @@ int auth_plain(arg) char *arg;
   if (tls_before_auth && !ssl) return err_wantstarttls();
 #endif
   if (*arg) {
-    if (r = b64decode(arg,str_len(arg),&resp) == 1) return err_input();
+    if ((r = b64decode(arg,str_len(arg),&resp)) == 1) return err_input();
   }
   else {
     out("334 \r\n"); flush();
     if (authgetl() < 0) return -1;
-    if (r = b64decode(authin.s,authin.len,&resp) == 1) return err_input();
+    if ((r = b64decode(authin.s,authin.len,&resp)) == 1) return err_input();
   }
   if (r == -1 || !stralloc_0(&resp)) die_nomem();
   while (resp.s[id]) id++;                       /* "authorize-id\0userid\0passwd\0" */
@@ -1297,140 +1293,6 @@ void smtp_tls(char *arg)
   else tls_init();
 }
 
-/*
- * Grab well-defined DH parameters from OpenSSL, see the get_rfc*
- * functions in <openssl/bn.h> for all available primes.
- */
-#if OPENSSL_VERSION_NUMBER < 0x10100005L
-static int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
-{
-  /* q is optional */
-  if (p == NULL || g == NULL)
-    return 0;
-  BN_free(dh->p);
-  BN_free(dh->q);
-  BN_free(dh->g);
-  dh->p = p;
-  dh->q = q;
-  dh->g = g;
-
-  if (q != NULL)
-    dh->length = BN_num_bits(q);
-
-  return 1;
-}
-#endif
-
-static DH *make_dh_params(BIGNUM *(*prime)(BIGNUM *))
-{
-  BIGNUM *p, *g;
-  DH *dh = DH_new();
-  if (!dh)
-    return NULL;
-
-  p = prime(NULL);
-  g = BN_new();
-  if (g != NULL)
-    BN_set_word(g, 2);
-  if (!p || !g || !DH_set0_pqg(dh, p, NULL, g)) {
-    DH_free(dh);
-    BN_free(p);
-    BN_free(g);
-    return NULL;
-  }
-  return dh;
-}
-
-/* Storage and initialization for DH parameters. */
-static struct dhparam {
-  BIGNUM *(*const prime)(BIGNUM *); /* function to generate... */
-  DH *dh;                           /* ...this, used for keys.... */
-  const unsigned int min;           /* ...of length >= this. */
-} dhparams[] = {
-  { get_rfc3526_prime_8192, NULL, 6145 },
-  { get_rfc3526_prime_6144, NULL, 4097 },
-  { get_rfc3526_prime_4096, NULL, 3073 },
-  { get_rfc3526_prime_3072, NULL, 2049 },
-  { get_rfc3526_prime_2048, NULL, 1025 },
-  { get_rfc2409_prime_1024, NULL, 0 }
-};
-
-/* Hand out the same DH structure though once generated as we leak
- * memory otherwise and freeing the structure up after use would be
- * hard to track and in fact is not needed at all as it is safe to
- * use the same parameters over and over again security wise (in
- * contrast to the keys itself) and code safe as the returned structure
- * is duplicated by OpenSSL anyway. Hence no modification happens
- * to our copy. */
-static DH *tmp_dh_cb(SSL *ssl, int export, int keylen)
-{
-  EVP_PKEY *pkey = SSL_get_privatekey(ssl);
-  int type = pkey ? EVP_PKEY_base_id(pkey) : EVP_PKEY_NONE;
-  unsigned n;
-
-  /*
-   * OpenSSL will call us with either keylen == 512 or keylen == 1024
-   * (see the definition of SSL_EXPORT_PKEYLENGTH in ssl_locl.h).
-   * Adjust the DH parameter length according to the size of the
-   * RSA/DSA private key used for the current connection, and always
-   * use at least 1024-bit parameters.
-   * Note: This may cause interoperability issues with implementations
-   * which limit their DH support to 1024 bit - e.g. Java 7 and earlier.
-   * In this case, SSLCertificateFile can be used to specify fixed
-   * 1024-bit DH parameters (with the effect that OpenSSL skips this
-   * callback).
-   */
-  if (type == EVP_PKEY_RSA || type == EVP_PKEY_DSA)
-    keylen = EVP_PKEY_bits(pkey);
-
-  for (n = 0; n < sizeof(dhparams)/sizeof(dhparams[0]); n++) {
-    if (keylen >= dhparams[n].min) {
-      if (dhparams[n].dh == NULL)
-        dhparams[n].dh = make_dh_params(dhparams[n].prime);
-      return dhparams[n].dh;
-    }
-  }
-
-  return NULL; /* impossible to reach. */
-}
-
-static DH *ssl_dh_GetParamFromFile(const char *file)
-{
-  DH *dh = NULL;
-  BIO *bio;
-
-  if ((bio = BIO_new_file(file, "r")) == NULL)
-    return NULL;
-  dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
-  BIO_free(bio);
-  if (!dh)
-    (void)ERR_get_error();
-  return dh;
-}
-
-#ifdef HAVE_ECC
-static EC_GROUP *ssl_ec_GetParamFromFile(const char *file)
-{
-  EC_GROUP *group = NULL;
-  BIO *bio;
-
-  if ((bio = BIO_new_file(file, "r")) == NULL)
-    return NULL;
-  group = PEM_read_bio_ECPKParameters(bio, NULL, NULL, NULL);
-  BIO_free(bio);
-  if (!group)
-    (void)ERR_get_error();
-  return group;
-}
-
-#if !defined(SSL_set_ecdh_auto)
-static EC_KEY *tmp_ecdh_cb(SSL *ssl, int export, int keylen)
-{
-  return EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
-}
-#endif
-#endif
-
 /* don't want to fail handshake if cert isn't verifiable */
 int verify_cb(int preverify_ok, X509_STORE_CTX *ctx) { return 1; }
 
@@ -1455,15 +1317,7 @@ void tls_init()
   SSL_CTX *ctx;
   const char *ciphers;
   stralloc saciphers = {0};
-  X509_STORE *store;
-  X509_LOOKUP *lookup;
   const char *servercert, *servercert2;
-  DH *dhparams;
-#ifdef HAVE_ECC
-  EC_GROUP *ecparams;
-  int nid;
-  EC_KEY *eckey = NULL;
-#endif
   struct stat st;
 
   /* if set, use servercert selected through SMTP_SERVERCERT env var */
@@ -1475,7 +1329,7 @@ void tls_init()
   SSL_library_init();
 
   /* a new SSL context with the bare minimum of options */
-  ctx = SSL_CTX_new(SSLv23_server_method());
+  ctx = SSL_CTX_new(TLS_server_method());
   if (!ctx) { tls_err("unable to initialize ctx"); return; }
   int min_ssl_version = (*childargs) ? TLS1_2_VERSION : TLS1_VERSION;
   SSL_CTX_set_min_proto_version(ctx, min_ssl_version);
@@ -1490,13 +1344,13 @@ void tls_init()
 
   /* this will also check whether public and private keys match */
   if (!SSL_CTX_use_PrivateKey_file(ctx, servercert, SSL_FILETYPE_PEM))
-    { SSL_free(myssl); tls_err("no valid private key"); return; }
+    { SSL_CTX_free(ctx); tls_err("no valid private key"); return; }
 
   if (stat(servercert2, &st) == 0) {
     if (!SSL_CTX_use_certificate_chain_file(ctx, servercert2))
-      { SSL_CTX_free(ctx); tls_err("missing alternate certificate"); return; }
+      { SSL_CTX_free(ctx); tls_err("invalid alternate certificate"); return; }
     if (!SSL_CTX_use_PrivateKey_file(ctx, servercert2, SSL_FILETYPE_PEM))
-      { SSL_free(myssl); tls_err("no valid alternate private key"); return; }
+      { SSL_CTX_free(ctx); tls_err("no valid alternate private key"); return; }
   }
 
   /* a new SSL object, with the rest added to it directly to avoid copying */
@@ -1519,39 +1373,17 @@ void tls_init()
   SSL_set_cipher_list(myssl, ciphers);
   alloc_free(saciphers.s);
 
-  //TODO: we shouldn't use hardcoded DH: see https://weakdh.org/
-  SSL_set_tmp_dh_callback(myssl, tmp_dh_cb);
-
-  /* try to read DH parameters from certificate */
-  if ((dhparams = ssl_dh_GetParamFromFile(servercert)))
-    SSL_set_tmp_dh(myssl, dhparams);
-
-#ifdef HAVE_ECC
-  /* similarly, try to read the ECDH curve name from certificate... */
-  if ((ecparams = ssl_ec_GetParamFromFile(servercert)) &&
-      (nid = EC_GROUP_get_curve_name(ecparams)) &&
-      (eckey = EC_KEY_new_by_curve_name(nid))) {
-    SSL_set_tmp_ecdh(myssl, eckey);
-  }
-  else {
-#if defined(SSL_set_ecdh_auto)
-    /* ...otherwise, enable auto curve selection (OpenSSL 1.0.2 and later) */
-    SSL_set_ecdh_auto(myssl, 1);
-#else
-    /* or set callback, which will configure NIST P-256 */
-    SSL_set_tmp_ecdh_callback(myssl, tmp_ecdh_cb);
-#endif
-  }
-  EC_KEY_free(eckey);
-#endif
+  SSL_set_dh_auto(myssl, 1);
+  SSL_set_ecdh_auto(myssl, 1);
 
-#if OPENSSL_VERSION_NUMBER >= 0x10100005L
   stralloc opensslconf = {0};
   if (control_readfile(&opensslconf, "control/opensslconf", 0) == -1)
     { SSL_free(myssl); die_control(); }
   if (opensslconf.len) {
     SSL_CONF_CTX *cctx = SSL_CONF_CTX_new();
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_FILE);
+    /* client + server so we can share one single file */
+    SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CLIENT);
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SERVER);
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CERTIFICATE);
     SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_SHOW_ERRORS);
@@ -1579,7 +1411,6 @@ void tls_init()
 
     (void)SSL_CONF_CTX_finish(cctx);
   }
-#endif
 
   SSL_set_rfd(myssl, ssl_rfd = substdio_fileno(&ssin));
   SSL_set_wfd(myssl, ssl_wfd = substdio_fileno(&ssout));