kdf: add key derivation functions
generic sha code from git://w1.fi/hostap.git commit
5ea93947ca67ba83529798b806a15b247cdb2e93 which also happens
to be the source of our milenage code.
Related: SYS#5324
Change-Id: Ibf2e49edada944d91ceba62bd0d6b6ce69261fcd
diff --git a/src/gsm/kdf/sha256.h b/src/gsm/kdf/sha256.h
new file mode 100644
index 0000000..b1ce6af
--- /dev/null
+++ b/src/gsm/kdf/sha256.h
@@ -0,0 +1,30 @@
+/*
+ * SHA256 hash implementation and interface functions
+ * Copyright (c) 2003-2011, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#ifndef SHA256_H
+#define SHA256_H
+
+#define SHA256_MAC_LEN 32
+
+void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
+ const u8 *addr[], const size_t *len, u8 *mac);
+void hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
+ size_t data_len, u8 *mac);
+void sha256_prf(const u8 *key, size_t key_len, const char *label,
+ const u8 *data, size_t data_len, u8 *buf, size_t buf_len);
+void tls_prf_sha256(const u8 *secret, size_t secret_len,
+ const char *label, const u8 *seed, size_t seed_len,
+ u8 *out, size_t outlen);
+
+#endif /* SHA256_H */