dirmngr: Use sks-keyservers CA by default for the hkps pool.

* dirmngr/Makefile.am (dist_pkgdata_DATA): Add sks-keyservers.netCA.pem.
* dirmngr/http.c (http_session_new): Add optional arg
intended_hostname and set a default cert.
* dirmngr/ks-engine-hkp.c (send_request): Pass httphost to
http_session_new.
--

Ship the certificate for the sks-keyservers hkps pool.  If the user
has specified that they want to use
hkps://hkps.pool.sks-keyservers.net, and they have not specified any
hkp-cacert explicitly, then initialize the trust path with this
specific trust anchor.

Co-authored-by: wk@gnupg.org
Signed-off-by: Werner Koch <wk@gnupg.org>

dirmngr/Makefile.am

@@ -20,6 +20,7 @@
 ## Process this file with automake to produce Makefile.in
 
 EXTRA_DIST = OAUTHORS ONEWS ChangeLog-2011 tls-ca.pem
+dist_pkgdata_DATA = sks-keyservers.netCA.pem
 
 bin_PROGRAMS = dirmngr dirmngr-client
 

dirmngr/http.c

@@ -562,7 +562,8 @@ http_session_release (http_session_t sess)
 /* Create a new session object which is currently used to enable TLS
    support.  It may eventually allow reusing existing connections.  */
 gpg_error_t
-http_session_new (http_session_t *r_session, const char *tls_priority)
+http_session_new (http_session_t *r_session, const char *tls_priority,
+                  const char *intended_hostname)
 {
   gpg_error_t err;
   http_session_t sess;
@@ -600,6 +601,34 @@ http_session_new (http_session_t *r_session, const char *tls_priority)
         goto leave;
       }
 
+    /* If the user has not specified a CA list, and they are looking
+     * for the hkps pool from sks-keyservers.net, then default to
+     * Kristian's certificate authority:  */
+    if (!tls_ca_certlist
+        && intended_hostname
+        && !ascii_strcasecmp (intended_hostname,
+                              "hkps.pool.sks-keyservers.net"))
+      {
+        char *pemname = make_filename_try (gnupg_datadir (),
+                                           "sks-keyservers.netCA.pem", NULL);
+        if (!pemname)
+          {
+            err = gpg_error_from_syserror ();
+            log_error ("setting CA from file '%s' failed: %s\n",
+                       pemname, gpg_strerror (err));
+          }
+        else
+          {
+            rc = gnutls_certificate_set_x509_trust_file
+              (sess->certcred, pemname, GNUTLS_X509_FMT_PEM);
+            if (rc < 0)
+              log_info ("setting CA from file '%s' failed: %s\n",
+                        pemname, gnutls_strerror (rc));
+            xfree (pemname);
+          }
+      }
+
+    /* Add configured certificates to the session.  */
     for (sl = tls_ca_certlist; sl; sl = sl->next)
       {
         rc = gnutls_certificate_set_x509_trust_file

dirmngr/http.h

@@ -98,7 +98,8 @@ void http_register_tls_callback (gpg_error_t (*cb)(http_t,http_session_t,int));
 void http_register_tls_ca (const char *fname);
 
 gpg_error_t http_session_new (http_session_t *r_session,
-                              const char *tls_priority);
+                              const char *tls_priority,
+                              const char *intended_hostname);
 http_session_t http_session_ref (http_session_t sess);
 void http_session_release (http_session_t sess);
 

dirmngr/ks-engine-hkp.c

@@ -991,7 +991,7 @@ send_request (ctrl_t ctrl, const char *request, const char *hostportstr,
 
   *r_fp = NULL;
 
-  err = http_session_new (&session, NULL);
+  err = http_session_new (&session, NULL, httphost);
   if (err)
     goto leave;
   http_session_set_log_cb (session, cert_log_cb);

dirmngr/ks-engine-http.c

@@ -65,7 +65,7 @@ ks_http_fetch (ctrl_t ctrl, const char *url, estream_t *r_fp)
   estream_t fp = NULL;
   char *request_buffer = NULL;
 
-  err = http_session_new (&session, NULL);
+  err = http_session_new (&session, NULL, NULL);
   if (err)
     goto leave;
   http_session_set_log_cb (session, cert_log_cb);

dirmngr/t-http.c

@@ -262,7 +262,7 @@ main (int argc, char **argv)
   http_register_tls_callback (verify_callback);
   http_register_tls_ca (cafile);
 
-  err = http_session_new (&session, NULL);
+  err = http_session_new (&session, NULL, NULL);
   if (err)
     log_error ("http_session_new failed: %s\n", gpg_strerror (err));