+
+#ifdef TLS_SUPPORT
+/*
+ * Negotiate TLS at this point. Will call pop_done() on failure.
+ */
+
+static int
+tls_negotiate(void)
+{
+ BIO *ssl_bio;
+
+ if (! sslctx) {
+ SSL_METHOD *method;
+
+ SSL_library_init();
+ SSL_load_error_strings();
+
+ method = TLS_client_method();
+
+ sslctx = SSL_CTX_new(method);
+
+ if (! sslctx()) {
+ pop_done();
+ advise(NULL, "Unable to initialize OpenSSL context: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ return NOTOK;
+ }
+ }
+
+ ssl = SSL_new(sslctx);
+
+ if (! ssl) {
+ pop_done();
+ advise(NULL, "Unable to create SSL connection: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ return NOTOK;
+ }
+
+ sbior = BIO_new_socket(fileno(input), BIO_NOCLOSE);
+ sbiow = BIO_new_socket(fileno(output), BIO_NOCLOSE);
+
+ if (sbior == NULL || sbiow == NULL) {
+ pop_done();
+ advise(NULL, "Unable to create BIO endpoints: %s",
+ ERR_error_string(ERR_get_error(), NULL);
+ return NOTOK;
+ }
+
+ SSL_set_bio(ssl, sbior, sbiow);
+ SSL_set_connect_state(ssl);
+
+ /*
+ * Set up a BIO to do buffering for us
+ */
+
+ io = BIO_new(BIO_f_buffer());
+
+ if (! io) {
+ pop_done();
+ advise(NULL, "Unable to create a buffer BIO: %s",
+ ERR_error_string(ERR_get_error(), NULL);
+ return NOTOK;
+ }
+
+ ssl_bio = BIO_new(BIO_f_ssl());
+
+ if (! ssl_bio) {
+ pop_done();
+ advise(NULL, "Unable to create a SSL BIO: %s",
+ ERR_error_string(ERR_get_error(), NULL);
+ return NOTOK;
+ }
+
+ BIO_set_ssl(ssl_bio, ssl, BIO_CLOSE);
+ BIO_push(io, ssl_bio);
+
+ /*
+ * Try doing the handshake now
+ */
+
+ if (BIO_do_handshake(io) < 1) {
+ pop_done();
+ advise(NULL, "Unable to negotiate SSL connection: %s",
+ ERR_error_string(ERR_get_error(), NULL);
+ return NOTOK;
+ }
+
+ if (popprint) {
+ const SSL_CIPHER *cipher = SSL_get_current_cipher(ssl);
+ printf("SSL negotiation successful: %s(%d) %s\n",
+ SSL_CIPHER_get_name(cipher);
+ SSL_CIPHER_get_bits(cipher, NULL);
+ SSL_CIPHER_get_version(cipher);
+ }
+
+ tls_active = 1;
+
+ return OK;
+}
+#endif /* TLS_SUPPORT */