Implement HKDF

1 files changed, 39 insertions, 0 deletions

diff --git a/src/hkdf_sha256.h b/src/hkdf_sha256.h
new file mode 100644
index 0000000..830d0aa
--- /dev/null
+++ b/src/hkdf_sha256.h
@@ -0,0 +1,39 @@
+/*
+  Copyright (c) 2012-2013, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#ifndef _FASTD_HKDF_SHA256_H_
+#define _FASTD_HKDF_SHA256_H_
+
+#include "sha256.h"
+
+
+static inline void fastd_hkdf_sha256_extract(fastd_sha256_t *out, const uint32_t salt[FASTD_HMACSHA256_KEY_WORDS], const uint32_t *in, size_t len) {
+	fastd_hmacsha256(out, salt, in, len);
+}
+
+void fastd_hkdf_sha256_expand(fastd_sha256_t *out, size_t blocks, fastd_sha256_t *prk, const uint8_t *info, size_t infolen);
+
+#endif /* _FASTD_HKDF_SHA256_H_ */