Add SHA-224/256 and HMAC-SHA-224/256 crypto hash

lib/sha256.h

@@ -0,0 +1,71 @@
+/*
+ *	BIRD Library -- SHA-256 and SHA-224 Hash Functions,
+ *			HMAC-SHA-256 and HMAC-SHA-224 Functions
+ *
+ *	(c) 2015 CZ.NIC z.s.p.o.
+ *
+ *	Based on the code from libgcrypt-1.6.0, which is
+ *	(c) 2003, 2006, 2008, 2009 Free Software Foundation, Inc.
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_SHA256_H_
+#define _BIRD_SHA256_H_
+
+#include "nest/bird.h"
+
+#define SHA224_SIZE 		28
+#define SHA224_HEX_SIZE		57
+#define SHA224_BLOCK_SIZE 	64
+
+#define SHA256_SIZE 		32
+#define SHA256_HEX_SIZE		65
+#define SHA256_BLOCK_SIZE 	64
+
+struct sha256_context {
+  u32  h0,h1,h2,h3,h4,h5,h6,h7;
+  byte buf[128];			/* 128 is for SHA384 and SHA512 support, otherwise for SHA224 and SHA256 is 64 enough */
+  u32 nblocks;
+  u32 nblocks_high;
+  int count;
+  u32 blocksize;
+  uint (*transform)(void *c, const byte *blks, size_t nblks);
+};
+#define sha224_context sha256_context	/* aliasing 'struct sha224_context' to 'struct sha256_context' */
+
+void sha256_init(struct sha256_context *ctx);
+void sha224_init(struct sha224_context *ctx);
+
+void sha256_update(struct sha256_context *ctx, const byte *in_buf, size_t in_len);
+static inline void sha224_update(struct sha224_context *ctx, const byte *in_buf, size_t in_len)
+{
+  sha256_update(ctx, in_buf, in_len);
+}
+
+byte* sha256_final(struct sha256_context *ctx);
+static inline byte* sha224_final(struct sha224_context *ctx)
+{
+  return sha256_final(ctx);
+}
+
+/*
+ *	HMAC-SHA256, HMAC-SHA224
+ */
+struct sha256_hmac_context
+{
+  struct sha256_context ictx;
+  struct sha256_context octx;
+};
+#define sha224_hmac_context sha256_hmac_context	/* aliasing 'struct sha224_hmac_context' to 'struct sha256_hmac_context' */
+
+void sha256_hmac_init(struct sha256_hmac_context *ctx, const byte *key, size_t keylen);
+void sha224_hmac_init(struct sha224_hmac_context *ctx, const byte *key,  size_t keylen);
+
+void sha256_hmac_update(struct sha256_hmac_context *ctx, const byte *buf, size_t buflen);
+void sha224_hmac_update(struct sha224_hmac_context *ctx, const byte *buf, size_t buflen);
+
+byte *sha256_hmac_final(struct sha256_hmac_context *ctx);
+byte *sha224_hmac_final(struct sha224_hmac_context *ctx);
+
+#endif /* _BIRD_SHA256_H_ */