Move m_getfld's MS_* mbox-type macros to the only user.

[nmh] / sbr / netsec.c

diff --git a/sbr/netsec.c b/sbr/netsec.c
index 990b2318a70d389e8889973401f5f66eaddce9be..ab05cf8e85e9235c6f874169bc0b488b40a36ec0 100644 (file)
--- a/sbr/netsec.c
+++ b/sbr/netsec.c
@@ -1,6 +1,4 @@
-
-/*
- * netsec.c -- Network security routines for handling protocols that
+/* netsec.c -- Network security routines for handling protocols that

  *            require SASL and/or TLS.
  *
  * This code is Copyright (c) 2016, by the authors of nmh.  See the
  *            require SASL and/or TLS.
  *
  * This code is Copyright (c) 2016, by the authors of nmh.  See the


@@ -56,12 +54,14 @@ static SSL_CTX *sslctx = NULL;              /* SSL Context */
 struct _netsec_context {
     int ns_readfd;             /* Read descriptor for network connection */
     int ns_writefd;            /* Write descriptor for network connection */
 struct _netsec_context {
     int ns_readfd;             /* Read descriptor for network connection */
     int ns_writefd;            /* Write descriptor for network connection */

+    int ns_noclose;            /* Do not close file descriptors if set */

     int ns_snoop;              /* If true, display network data */
     int ns_snoop_noend;                /* If true, didn't get a CR/LF on last line */
     netsec_snoop_callback *ns_snoop_cb; /* Snoop output callback */
     void *ns_snoop_context;    /* Context data for snoop function */
     int ns_timeout;            /* Network read timeout, in seconds */
     char *ns_userid;           /* Userid for authentication */
     int ns_snoop;              /* If true, display network data */
     int ns_snoop_noend;                /* If true, didn't get a CR/LF on last line */
     netsec_snoop_callback *ns_snoop_cb; /* Snoop output callback */
     void *ns_snoop_context;    /* Context data for snoop function */
     int ns_timeout;            /* Network read timeout, in seconds */
     char *ns_userid;           /* Userid for authentication */

+    char *ns_hostname;         /* Hostname we've connected to */

     unsigned char *ns_inbuffer;        /* Our read input buffer */
     unsigned char *ns_inptr;   /* Our read buffer input pointer */
     unsigned int ns_inbuflen;  /* Length of data in input buffer */
     unsigned char *ns_inbuffer;        /* Our read input buffer */
     unsigned char *ns_inptr;   /* Our read buffer input pointer */
     unsigned int ns_inbuflen;  /* Length of data in input buffer */


@@ -77,7 +77,6 @@ struct _netsec_context {
     char *oauth_service;       /* OAuth2 service name */
 #endif /* OAUTH_SUPPORT */
 #ifdef CYRUS_SASL
     char *oauth_service;       /* OAuth2 service name */
 #endif /* OAUTH_SUPPORT */
 #ifdef CYRUS_SASL

-    char *sasl_hostname;       /* Hostname we've connected to */

     sasl_conn_t *sasl_conn;    /* SASL connection context */
     sasl_ssf_t sasl_ssf;       /* SASL Security Strength Factor */
     sasl_callback_t *sasl_cbs; /* Callbacks used by SASL */
     sasl_conn_t *sasl_conn;    /* SASL connection context */
     sasl_ssf_t sasl_ssf;       /* SASL Security Strength Factor */
     sasl_callback_t *sasl_cbs; /* Callbacks used by SASL */


@@ -142,11 +141,13 @@ netsec_init(void)
     NEW(nsc);
     nsc->ns_readfd = -1;
     nsc->ns_writefd = -1;
     NEW(nsc);
     nsc->ns_readfd = -1;
     nsc->ns_writefd = -1;

+    nsc->ns_noclose = 0;

     nsc->ns_snoop = 0;
     nsc->ns_snoop_noend = 0;
     nsc->ns_snoop_cb = NULL;
     nsc->ns_snoop_context = NULL;
     nsc->ns_userid = NULL;
     nsc->ns_snoop = 0;
     nsc->ns_snoop_noend = 0;
     nsc->ns_snoop_cb = NULL;
     nsc->ns_snoop_context = NULL;
     nsc->ns_userid = NULL;

+    nsc->ns_hostname = NULL;

     nsc->ns_timeout = 60;      /* Our default */
     nsc->ns_inbufsize = NETSEC_BUFSIZE;
     nsc->ns_inbuffer = mh_xmalloc(nsc->ns_inbufsize);
     nsc->ns_timeout = 60;      /* Our default */
     nsc->ns_inbufsize = NETSEC_BUFSIZE;
     nsc->ns_inbuffer = mh_xmalloc(nsc->ns_inbufsize);


@@ -164,7 +165,6 @@ netsec_init(void)
 #endif /* OAUTH_SUPPORT */
 #ifdef CYRUS_SASL
     nsc->sasl_conn = NULL;
 #endif /* OAUTH_SUPPORT */
 #ifdef CYRUS_SASL
     nsc->sasl_conn = NULL;

-    nsc->sasl_hostname = NULL;

     nsc->sasl_cbs = NULL;
     nsc->sasl_creds = NULL;
     nsc->sasl_secret = NULL;
     nsc->sasl_cbs = NULL;
     nsc->sasl_creds = NULL;
     nsc->sasl_secret = NULL;


@@ -182,33 +182,24 @@ netsec_init(void)
 
 /*
  * Shutdown the connection completely and free all resources.
 
 /*
  * Shutdown the connection completely and free all resources.

- * The connection is only closed if the flag is given.

  */
 
 void
  */
 
 void

-netsec_shutdown(netsec_context *nsc, int closeflag)
+netsec_shutdown(netsec_context *nsc)

 {
 {

-    if (nsc->ns_userid)
-       free(nsc->ns_userid);
-    if (nsc->ns_inbuffer)
-       free(nsc->ns_inbuffer);
-    if (nsc->ns_outbuffer)
-       free(nsc->ns_outbuffer);
-    if (nsc->sasl_mech)
-       free(nsc->sasl_mech);
-    if (nsc->sasl_chosen_mech)
-       free(nsc->sasl_chosen_mech);
+    mh_xfree(nsc->ns_userid);
+    mh_xfree(nsc->ns_hostname);
+    mh_xfree(nsc->ns_inbuffer);
+    mh_xfree(nsc->ns_outbuffer);
+    mh_xfree(nsc->sasl_mech);
+    mh_xfree(nsc->sasl_chosen_mech);

 #ifdef OAUTH_SERVICE
 #ifdef OAUTH_SERVICE

-    if (nsc->oauth_service)
-       free(nsc->oauth_service);
+    mh_xfree(nsc->oauth_service);

 #endif /* OAUTH_SERVICE */
 #ifdef CYRUS_SASL
     if (nsc->sasl_conn)
        sasl_dispose(&nsc->sasl_conn);
 #endif /* OAUTH_SERVICE */
 #ifdef CYRUS_SASL
     if (nsc->sasl_conn)
        sasl_dispose(&nsc->sasl_conn);

-    if (nsc->sasl_hostname)
-       free(nsc->sasl_hostname);
-    if (nsc->sasl_cbs)
-       free(nsc->sasl_cbs);
+    mh_xfree(nsc->sasl_cbs);

     if (nsc->sasl_creds)
        nmh_credentials_free(nsc->sasl_creds);
     if (nsc->sasl_secret) {
     if (nsc->sasl_creds)
        nmh_credentials_free(nsc->sasl_creds);
     if (nsc->sasl_secret) {


@@ -217,8 +208,7 @@ netsec_shutdown(netsec_context *nsc, int closeflag)
        }
        free(nsc->sasl_secret);
     }
        }
        free(nsc->sasl_secret);
     }

-    if (nsc->sasl_tmpbuf)
-       free(nsc->sasl_tmpbuf);
+    mh_xfree(nsc->sasl_tmpbuf);

 #endif /* CYRUS_SASL */
 #ifdef TLS_SUPPORT
     if (nsc->ssl_io)
 #endif /* CYRUS_SASL */
 #ifdef TLS_SUPPORT
     if (nsc->ssl_io)


@@ -229,7 +219,7 @@ netsec_shutdown(netsec_context *nsc, int closeflag)
        BIO_free_all(nsc->ssl_io);
 #endif /* TLS_SUPPORT */
 
        BIO_free_all(nsc->ssl_io);
 #endif /* TLS_SUPPORT */
 

-    if (closeflag) {
+    if (! nsc->ns_noclose) {

        if (nsc->ns_readfd != -1)
            close(nsc->ns_readfd);
        if (nsc->ns_writefd != -1 && nsc->ns_writefd != nsc->ns_readfd)
        if (nsc->ns_readfd != -1)
            close(nsc->ns_readfd);
        if (nsc->ns_writefd != -1 && nsc->ns_writefd != nsc->ns_readfd)


@@ -260,6 +250,16 @@ netsec_set_userid(netsec_context *nsc, const char *userid)
     nsc->ns_userid = getcpy(userid);
 }
 
     nsc->ns_userid = getcpy(userid);
 }
 

+/*
+ * Set the hostname of the remote host we're connecting to.
+ */
+
+void
+netsec_set_hostname(netsec_context *nsc, const char *hostname)
+{
+    nsc->ns_hostname = mh_xstrdup(hostname);
+}
+

 /*
  * Get the snoop flag for this connection
  */
 /*
  * Get the snoop flag for this connection
  */


@@ -392,7 +392,7 @@ netsec_read(netsec_context *nsc, void *buffer, size_t size, char **errstr)
      * assume here that this has something in it.
      */
 
      * assume here that this has something in it.
      */
 

-    retlen = size > nsc->ns_inbuflen ? nsc->ns_inbuflen : size;
+    retlen = min(size, nsc->ns_inbuflen);

 
     memcpy(buffer, nsc->ns_inptr, retlen);
 
 
     memcpy(buffer, nsc->ns_inptr, retlen);
 


@@ -627,7 +627,8 @@ retry:
            if (nsc->ns_snoop)
                ERR_print_errors_fp(stderr);
            return NOTOK;
            if (nsc->ns_snoop)
                ERR_print_errors_fp(stderr);
            return NOTOK;

-       } else if (rc < 0) {
+       }
+        if (rc < 0) {

            /* Definitely an error */
            netsec_err(errstr, "Read on TLS connection failed: %s",
                       ERR_error_string(ERR_get_error(), NULL));
            /* Definitely an error */
            netsec_err(errstr, "Read on TLS connection failed: %s",
                       ERR_error_string(ERR_get_error(), NULL));


@@ -826,19 +827,18 @@ retry:
                       "%d bytes, but our buffer size was only %d bytes",
                       rc, nsc->ns_outbufsize);
            return NOTOK;
                       "%d bytes, but our buffer size was only %d bytes",
                       rc, nsc->ns_outbufsize);
            return NOTOK;

-       } else {
-           /*
-            * Generate a flush (which may be inefficient, but hopefully
-            * it isn't) and then try again.
-            */
-           if (netsec_flush(nsc, errstr) != OK)
-               return NOTOK;
-           /*
-            * After this, outbuffer should == outptr, so we shouldn't
-            * hit this next time around.
-            */
-           goto retry;

        }
        }

+        /*
+         * Generate a flush (which may be inefficient, but hopefully
+         * it isn't) and then try again.
+         */
+        if (netsec_flush(nsc, errstr) != OK)
+            return NOTOK;
+        /*
+         * After this, outbuffer should == outptr, so we shouldn't
+         * hit this next time around.
+         */
+        goto retry;

     }
 
     if (nsc->ns_snoop) {
     }
 
     if (nsc->ns_snoop) {


@@ -946,14 +946,19 @@ netsec_flush(netsec_context *nsc, char **errstr)
  */
 
 int
  */
 
 int

-netsec_set_sasl_params(netsec_context *nsc, const char *hostname,
-                      const char *service, const char *mechanism,
-                      netsec_sasl_callback callback, char **errstr)
+netsec_set_sasl_params(netsec_context *nsc, const char *service,
+                      const char *mechanism, netsec_sasl_callback callback,
+                      char **errstr)

 {
 #ifdef CYRUS_SASL
     sasl_callback_t *sasl_cbs;
     int retval;
 
 {
 #ifdef CYRUS_SASL
     sasl_callback_t *sasl_cbs;
     int retval;
 

+    if (!nsc->ns_hostname) {
+       netsec_err(errstr, "Internal error: ns_hostname is NULL");
+       return NOTOK;
+    }
+

     if (! sasl_initialized) {
        retval = sasl_client_init(NULL);
        if (retval != SASL_OK) {
     if (! sasl_initialized) {
        retval = sasl_client_init(NULL);
        if (retval != SASL_OK) {


@@ -989,8 +994,8 @@ netsec_set_sasl_params(netsec_context *nsc, const char *hostname,
 
     nsc->sasl_cbs = sasl_cbs;
 
 
     nsc->sasl_cbs = sasl_cbs;
 

-    retval = sasl_client_new(service, hostname, NULL, NULL, nsc->sasl_cbs, 0,
-                            &nsc->sasl_conn);
+    retval = sasl_client_new(service, nsc->ns_hostname, NULL, NULL,
+                            nsc->sasl_cbs, 0, &nsc->sasl_conn);

 
     if (retval) {
        netsec_err(errstr, "SASL new client allocation failed: %s",
 
     if (retval) {
        netsec_err(errstr, "SASL new client allocation failed: %s",


@@ -998,23 +1003,20 @@ netsec_set_sasl_params(netsec_context *nsc, const char *hostname,
        return NOTOK;
     }
 
        return NOTOK;
     }
 

-    nsc->sasl_hostname = mh_xstrdup(hostname);
-

     /*
      * Set up our credentials
      */
 
     /*
      * Set up our credentials
      */
 

-    nsc->sasl_creds = nmh_get_credentials(nsc->sasl_hostname, nsc->ns_userid);
+    nsc->sasl_creds = nmh_get_credentials(nsc->ns_hostname, nsc->ns_userid);

 
 #else /* CYRUS_SASL */
 
 #else /* CYRUS_SASL */

-    NMH_UNUSED(hostname);

     NMH_UNUSED(service);
     NMH_UNUSED(errstr);
 #endif /* CYRUS_SASL */
 
     /*
      * According to the RFC, mechanisms can only be uppercase letter, numbers,
     NMH_UNUSED(service);
     NMH_UNUSED(errstr);
 #endif /* CYRUS_SASL */
 
     /*
      * According to the RFC, mechanisms can only be uppercase letter, numbers,

-     * and a hypen or underscore.  So make sure we uppercase any letters
+     * and a hyphen or underscore.  So make sure we uppercase any letters

      * in case the user passed in lowercase.
      */
 
      * in case the user passed in lowercase.
      */
 


@@ -1023,7 +1025,7 @@ netsec_set_sasl_params(netsec_context *nsc, const char *hostname,
        nsc->sasl_mech = mh_xstrdup(mechanism);
 
        for (p = nsc->sasl_mech; *p; p++)
        nsc->sasl_mech = mh_xstrdup(mechanism);
 
        for (p = nsc->sasl_mech; *p; p++)

-           if (isascii((unsigned char) *p))    /* Just in case */
+           if (isascii((unsigned char) *p)) /* Leave non-ASCII lower alone. */

                *p = toupper((unsigned char) *p);
     }
 
                *p = toupper((unsigned char) *p);
     }
 


@@ -1277,8 +1279,7 @@ netsec_negotiate_sasl(netsec_context *nsc, const char *mechlist, char **errstr)
        rc = sasl_client_step(nsc->sasl_conn, (char *) outbuf, outbuflen, NULL,
                              (const char **) &saslbuf, &saslbuflen);
 
        rc = sasl_client_step(nsc->sasl_conn, (char *) outbuf, outbuflen, NULL,
                              (const char **) &saslbuf, &saslbuflen);
 

-       if (outbuf)
-           free(outbuf);
+        mh_xfree(outbuf);

 
        if (rc != SASL_OK && rc != SASL_CONTINUE) {
            netsec_err(errstr, "SASL client negotiation failed: %s",
 
        if (rc != SASL_OK && rc != SASL_CONTINUE) {
            netsec_err(errstr, "SASL client negotiation failed: %s",


@@ -1430,12 +1431,12 @@ netsec_set_oauth_service(netsec_context *nsc, const char *service)
  */
 
 int
  */
 
 int

-netsec_set_tls(netsec_context *nsc, int tls, char **errstr)
+netsec_set_tls(netsec_context *nsc, int tls, int noverify, char **errstr)

 {
 {

-    if (tls) {

 #ifdef TLS_SUPPORT
 #ifdef TLS_SUPPORT

+    if (tls) {

        SSL *ssl;
        SSL *ssl;

-       BIO *rbio, *wbio, *ssl_bio;;
+        BIO *rbio, *wbio, *ssl_bio;

 
        if (! tls_initialized) {
            SSL_library_init();
 
        if (! tls_initialized) {
            SSL_library_init();


@@ -1458,6 +1459,13 @@ netsec_set_tls(netsec_context *nsc, int tls, char **errstr)
            SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
                                SSL_OP_NO_TLSv1);
 
            SSL_CTX_set_options(sslctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
                                SSL_OP_NO_TLSv1);
 

+           if (!SSL_CTX_set_default_verify_paths(sslctx)) {
+               netsec_err(errstr, "Unable to set default certificate "
+                          "verification paths: %s",
+                          ERR_error_string(ERR_get_error(), NULL));
+               return NOTOK;
+           }
+

            tls_initialized++;
        }
 
            tls_initialized++;
        }
 


@@ -1500,7 +1508,7 @@ netsec_set_tls(netsec_context *nsc, int tls, char **errstr)
         * SSL BIO -> socket BIO.
         */
 
         * SSL BIO -> socket BIO.
         */
 

-       rbio = BIO_new_socket(nsc->ns_readfd, BIO_NOCLOSE);
+       rbio = BIO_new_socket(nsc->ns_readfd, BIO_CLOSE);

 
        if (! rbio) {
            netsec_err(errstr, "Unable to create a read socket BIO: %s",
 
        if (! rbio) {
            netsec_err(errstr, "Unable to create a read socket BIO: %s",


@@ -1509,7 +1517,7 @@ netsec_set_tls(netsec_context *nsc, int tls, char **errstr)
            return NOTOK;
        }
 
            return NOTOK;
        }
 

-       wbio = BIO_new_socket(nsc->ns_writefd, BIO_NOCLOSE);
+       wbio = BIO_new_socket(nsc->ns_writefd, BIO_CLOSE);

 
        if (! wbio) {
            netsec_err(errstr, "Unable to create a write socket BIO: %s",
 
        if (! wbio) {
            netsec_err(errstr, "Unable to create a write socket BIO: %s",


@@ -1522,6 +1530,42 @@ netsec_set_tls(netsec_context *nsc, int tls, char **errstr)
        SSL_set_bio(ssl, rbio, wbio);
        SSL_set_connect_state(ssl);
 
        SSL_set_bio(ssl, rbio, wbio);
        SSL_set_connect_state(ssl);
 

+       /*
+        * If noverify is NOT set, then do certificate validation.
+        * Turning on SSL_VERIFY_PEER will verify the certificate chain
+        * against locally stored root certificates (the locations are
+        * set using SSL_CTX_set_default_verify_paths()), and we put
+        * the hostname in the X509 verification parameters so the OpenSSL
+        * code will verify that the hostname appears in the server
+        * certificate.
+        */
+
+       if (! noverify) {
+#ifdef HAVE_X509_VERIFY_PARAM_SET1_HOST
+           X509_VERIFY_PARAM *param;
+#endif /* HAVE_X509_VERIFY_PARAM_SET1_HOST */
+
+           SSL_set_verify(ssl, SSL_VERIFY_PEER, NULL);
+           if (! nsc->ns_hostname) {
+               netsec_err(errstr, "Internal error: hostname not set and "
+                          "certification verification enabled");
+               SSL_free(ssl);
+               return NOTOK;
+           }
+
+#ifdef HAVE_X509_VERIFY_PARAM_SET1_HOST
+           param = SSL_get0_param(ssl);
+
+           if (! X509_VERIFY_PARAM_set1_host(param, nsc->ns_hostname, 0)) {
+               netsec_err(errstr, "Unable to add hostname %s to cert "
+                          "verification parameters: %s", nsc->ns_hostname,
+                          ERR_error_string(ERR_get_error(), NULL));
+               SSL_free(ssl);
+               return NOTOK;
+           }
+#endif /* HAVE_X509_VERIFY_PARAM_SET1_HOST */
+       }
+

        ssl_bio = BIO_new(BIO_f_ssl());
 
        if (! ssl_bio) {
        ssl_bio = BIO_new(BIO_f_ssl());
 
        if (! ssl_bio) {


@@ -1534,19 +1578,29 @@ netsec_set_tls(netsec_context *nsc, int tls, char **errstr)
        BIO_set_ssl(ssl_bio, ssl, BIO_CLOSE);
        nsc->ssl_io = ssl_bio;
 
        BIO_set_ssl(ssl_bio, ssl, BIO_CLOSE);
        nsc->ssl_io = ssl_bio;
 

-       return OK;
-    } else {
-       BIO_free_all(nsc->ssl_io);
-       nsc->ssl_io = NULL;
+       /*
+        * Since SSL now owns these file descriptors, have it handle the
+        * closing of them instead of netsec_shutdown().
+        */
+
+       nsc->ns_noclose = 1;

 
        return OK;
     }
 
        return OK;
     }

+    BIO_free_all(nsc->ssl_io);
+    nsc->ssl_io = NULL;
+

 #else /* TLS_SUPPORT */
 #else /* TLS_SUPPORT */

-       netsec_err(errstr, "TLS is not supported");
+    NMH_UNUSED(nsc);
+    NMH_UNUSED(noverify);

 
 

+    if (tls) {
+       netsec_err(errstr, "TLS is not supported");

        return NOTOK;
     }
 #endif /* TLS_SUPPORT */
        return NOTOK;
     }
 #endif /* TLS_SUPPORT */

+
+    return OK;

 }
 
 /*
 }
 
 /*


@@ -1563,8 +1617,42 @@ netsec_negotiate_tls(netsec_context *nsc, char **errstr)
     }
 
     if (BIO_do_handshake(nsc->ssl_io) < 1) {
     }
 
     if (BIO_do_handshake(nsc->ssl_io) < 1) {

-       netsec_err(errstr, "TLS negotiation failed: %s",
-                  ERR_error_string(ERR_get_error(), NULL));
+       unsigned long errcode = ERR_get_error();
+
+       /*
+        * Print a more detailed message if it was certificate verification
+        * failure.
+        */
+
+       if (ERR_GET_LIB(errcode) == ERR_LIB_SSL &&
+               ERR_GET_REASON(errcode) == SSL_R_CERTIFICATE_VERIFY_FAILED) {
+           SSL *ssl;
+
+           if (BIO_get_ssl(nsc->ssl_io, &ssl) < 1) {
+               netsec_err(errstr, "Certificate verification failed, but "
+                          "cannot retrieve SSL handle: %s",
+                           ERR_error_string(errcode, NULL));
+           } else {
+               netsec_err(errstr, "Server certificate verification failed: %s",
+                          X509_verify_cert_error_string(
+                                               SSL_get_verify_result(ssl)));
+           }
+       } else {
+           netsec_err(errstr, "TLS negotiation failed: %s",
+                       ERR_error_string(errcode, NULL));
+       }
+
+       /*
+        * Because negotiation failed, shut down TLS so we don't get any
+        * garbage on the connection.  Because of weirdness with SSL_shutdown,
+        * we end up calling it twice: once explicitly, once as part of
+        * BIO_free_all().
+        */
+
+       BIO_ssl_shutdown(nsc->ssl_io);
+       BIO_free_all(nsc->ssl_io);
+       nsc->ssl_io = NULL;
+

        return NOTOK;
     }
 
        return NOTOK;
     }
 


@@ -1579,6 +1667,7 @@ netsec_negotiate_tls(netsec_context *nsc, char **errstr)
                    SSL_CIPHER_get_name(cipher),
                    SSL_CIPHER_get_bits(cipher, NULL),
                    SSL_CIPHER_get_version(cipher));
                    SSL_CIPHER_get_name(cipher),
                    SSL_CIPHER_get_bits(cipher, NULL),
                    SSL_CIPHER_get_version(cipher));

+           SSL_SESSION_print_fp(stderr, SSL_get_session(ssl));

        }
     }
 
        }
     }
 


@@ -1586,6 +1675,7 @@ netsec_negotiate_tls(netsec_context *nsc, char **errstr)
 
     return OK;
 #else /* TLS_SUPPORT */
 
     return OK;
 #else /* TLS_SUPPORT */

+    NMH_UNUSED(nsc);

     netsec_err(errstr, "TLS not supported");
 
     return NOTOK;
     netsec_err(errstr, "TLS not supported");
 
     return NOTOK;