Adds KDF based on SP 800-56A. Currently it is revision 1 (alternative 1). It should be extended to revision 2.

1 files changed, 58 insertions, 0 deletions

diff --git a/src/lib/kdf/sp800_56a/sp800_56a.h b/src/lib/kdf/sp800_56a/sp800_56a.h
new file mode 100644
index 000000000..822f5ca1a
--- /dev/null
+++ b/src/lib/kdf/sp800_56a/sp800_56a.h
@@ -0,0 +1,58 @@
+/*
+* KDF defined in NIST SP 800-56a (Approved Alternative 1)
+* (C) 2016 Krzysztof Kwiatkowski
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_SP800_56A_H__
+#define BOTAN_SP800_56A_H__
+
+#include <botan/kdf.h>
+#include <botan/hash.h>
+
+namespace Botan {
+
+/**
+ * NIST SP 800-56A KDF
+ */
+class BOTAN_DLL SP800_56A final : public KDF
+   {
+   public:
+      std::string name() const override { return "SP800-56A(" + m_hash->name() + ")"; }
+
+      KDF* clone() const override { return new SP800_56A(m_hash->clone()); }
+
+      /**
+      * Derive a key using the SP800-56A KDF.
+      *
+      * The implementation hard codes the context value for the
+      * expansion step to the empty string.
+      *
+      * @param key derived keying material K_M
+      * @param key_len the desired output length in bytes
+      * @param secret shared secret Z
+      * @param secret_len size of Z in bytes
+      * @param salt salt not used by an algorithm
+      * @param salt_len not used by an algorithm
+      * @param label label for the expansion step
+      * @param label_len size of label in bytes
+      *
+      * @throws Invalid_Argument key_len > 2^32
+      */
+      size_t kdf(uint8_t key[], size_t key_len,
+                 const uint8_t secret[], size_t secret_len,
+                 const uint8_t salt[], size_t salt_len,
+                 const uint8_t label[], size_t label_len) const override;
+
+      /**
+      * @param hash HASH algorithm used
+      */
+      explicit SP800_56A(HashFunction* hash) : m_hash(hash) {}
+   private:
+      std::unique_ptr<HashFunction> m_hash;
+   };
+}
+
+#endif
+