Simplify the way default certs are used
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index ba65131..2d81e75 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -224,7 +224,7 @@
     pk_context pkey;
     x509_crt srvcert2;
     pk_context pkey2;
-    int key_cert_provided = 0;
+    int key_cert_init = 0, key_cert_init2 = 0;
 #endif
 #if defined(POLARSSL_SSL_CACHE_C)
     ssl_cache_context cache;
@@ -574,7 +574,7 @@
 #if defined(POLARSSL_FS_IO)
     if( strlen( opt.crt_file ) )
     {
-        key_cert_provided = 1;
+        key_cert_init++;
         if( ( ret = x509_crt_parse_file( &srvcert, opt.crt_file ) ) != 0 )
         {
             printf( " failed\n  !  x509_crt_parse_file returned -0x%x\n\n",
@@ -584,16 +584,22 @@
     }
     if( strlen( opt.key_file ) )
     {
-        key_cert_provided = 1;
+        key_cert_init++;
         if( ( ret = pk_parse_keyfile( &pkey, opt.key_file, "" ) ) != 0 )
         {
             printf( " failed\n  !  pk_parse_keyfile returned -0x%x\n\n", -ret );
             goto exit;
         }
     }
+    if( key_cert_init == 1 )
+    {
+        printf( " failed\n  !  crt_file without key_file or vice-versa\n\n" );
+        goto exit;
+    }
+
     if( strlen( opt.crt_file2 ) )
     {
-        key_cert_provided = 1;
+        key_cert_init2++;
         if( ( ret = x509_crt_parse_file( &srvcert2, opt.crt_file2 ) ) != 0 )
         {
             printf( " failed\n  !  x509_crt_parse_file(2) returned -0x%x\n\n",
@@ -603,7 +609,7 @@
     }
     if( strlen( opt.key_file2 ) )
     {
-        key_cert_provided = 1;
+        key_cert_init2++;
         if( ( ret = pk_parse_keyfile( &pkey2, opt.key_file2, "" ) ) != 0 )
         {
             printf( " failed\n  !  pk_parse_keyfile(2) returned -0x%x\n\n",
@@ -611,42 +617,53 @@
             goto exit;
         }
     }
+    if( key_cert_init2 == 1 )
+    {
+        printf( " failed\n  !  crt_file2 without key_file2 or vice-versa\n\n" );
+        goto exit;
+    }
 #endif
-    if( key_cert_provided == 0 )
+    if( key_cert_init == 0 && key_cert_init2 == 0 )
     {
 #if !defined(POLARSSL_CERTS_C)
         printf( "Not certificated or key provided, and \n"
                 "POLARSSL_CERTS_C not defined!\n" );
         goto exit;
 #else
+#if defined(POLARSSL_RSA_C)
         if( ( ret = x509_crt_parse( &srvcert,
-                                    (const unsigned char *) test_srv_crt,
-                                    strlen( test_srv_crt ) ) ) != 0 )
+                                    (const unsigned char *) test_srv_crt_rsa,
+                                    strlen( test_srv_crt_rsa ) ) ) != 0 )
         {
             printf( " failed\n  !  x509_crt_parse returned -0x%x\n\n", -ret );
             goto exit;
         }
-        if( ( ret = pk_parse_key( &pkey, (const unsigned char *) test_srv_key,
-                                  strlen( test_srv_key ), NULL, 0 ) ) != 0 )
+        if( ( ret = pk_parse_key( &pkey,
+                                  (const unsigned char *) test_srv_key_rsa,
+                                  strlen( test_srv_key_rsa ), NULL, 0 ) ) != 0 )
         {
             printf( " failed\n  !  pk_parse_key returned -0x%x\n\n", -ret );
             goto exit;
         }
-#if defined(POLARSSL_RSA_C) && defined(POLARSSL_ECDSA_C)
+        key_cert_init = 2;
+#endif /* POLARSSL_RSA_C */
+#if defined(POLARSSL_ECDSA_C)
         if( ( ret = x509_crt_parse( &srvcert2,
-                                    (const unsigned char *) test_srv_crt2,
-                                    strlen( test_srv_crt2 ) ) ) != 0 )
+                                    (const unsigned char *) test_srv_crt_ec,
+                                    strlen( test_srv_crt_ec ) ) ) != 0 )
         {
             printf( " failed\n  !  x509_crt_parse2 returned -0x%x\n\n", -ret );
             goto exit;
         }
-        if( ( ret = pk_parse_key( &pkey2, (const unsigned char *) test_srv_key2,
-                                  strlen( test_srv_key2 ), NULL, 0 ) ) != 0 )
+        if( ( ret = pk_parse_key( &pkey2,
+                                  (const unsigned char *) test_srv_key_ec,
+                                  strlen( test_srv_key_ec ), NULL, 0 ) ) != 0 )
         {
             printf( " failed\n  !  pk_parse_key2 returned -0x%x\n\n", -ret );
             goto exit;
         }
-#endif /* POLARSSL_RSA_C && POLARSSL_ECDSA_C */
+        key_cert_init2 = 2;
+#endif /* POLARSSL_ECDSA_C */
 #endif /* POLARSSL_CERTS_C */
     }
 
@@ -706,10 +723,10 @@
 
 #if defined(POLARSSL_X509_CRT_PARSE_C)
     ssl_set_ca_chain( &ssl, &cacert, NULL, NULL );
-    ssl_set_own_cert( &ssl, &srvcert, &pkey );
-#if defined(POLARSSL_RSA_C) && defined(POLARSSL_ECDSA_C)
-    ssl_set_own_cert( &ssl, &srvcert2, &pkey2 );
-#endif
+    if( key_cert_init )
+        ssl_set_own_cert( &ssl, &srvcert, &pkey );
+    if( key_cert_init2 )
+        ssl_set_own_cert( &ssl, &srvcert2, &pkey2 );
 #endif
 
 #if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED)