Add ssl_cipher_is_permitted(), an internal helper function that

will be used in a few places shortly, e.g. in
ssl_cipher_list_to_bytes().

ok jsing

1 files changed, 44 insertions, 0 deletions

diff --git a/src/lib/libssl/ssl_ciphers.c b/src/lib/libssl/ssl_ciphers.c
new file mode 100644
index 0000000000..081a35ddb2
--- /dev/null
+++ b/src/lib/libssl/ssl_ciphers.c
@@ -0,0 +1,44 @@
+/*      $OpenBSD: ssl_ciphers.c,v 1.1 2019/01/21 10:28:52 tb Exp $ */
+/*
+ * Copyright (c) 2019 Theo Buehler <tb@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ssl_locl.h"
+
+int
+ssl_cipher_is_permitted(const SSL_CIPHER *cipher, uint16_t min_ver,
+    uint16_t max_ver)
+{
+        /* XXX: We only support DTLSv1 which is effectively TLSv1.1 */
+        if (min_ver == DTLS1_VERSION || max_ver == DTLS1_VERSION)
+                min_ver = max_ver = TLS1_1_VERSION;
+
+        switch(cipher->algorithm_ssl) {
+        case SSL_SSLV3:
+                if (min_ver <= TLS1_2_VERSION)
+                        return 1;
+                break;
+        case SSL_TLSV1_2:
+                if (min_ver <= TLS1_2_VERSION && TLS1_2_VERSION <= max_ver)
+                        return 1;
+                break;
+        case SSL_TLSV1_3:
+                if (min_ver <= TLS1_3_VERSION && TLS1_3_VERSION <= max_ver)
+                        return 1;
+                break;
+        }
+
+        return 0;
+}