[PATCH 06/15] Implement SHA2-224 submode of SHA2-256

[Sebastian Huber]

From: Conrad Meyer <cem at FreeBSD.org>

Like SHA2-384:SHA2-512, SHA2-224 is simply a truncated SHA2-256 with a
different initial vector.  Add to round out the complete basic SHA2 family.
---
 cpukit/include/sha224.h | 62 +++++++++++++++++++++++++++++++++++++++++
 cpukit/libmd/sha256c.c  | 51 +++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)
 create mode 100644 cpukit/include/sha224.h

diff --git a/cpukit/include/sha224.h b/cpukit/include/sha224.h
new file mode 100644
index 0000000000..3085c7fcb2
--- /dev/null
+++ b/cpukit/include/sha224.h
@@ -0,0 +1,62 @@
+/*-
+ * Copyright 2005 Colin Percival
+ * 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 AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SHA224_H_
+#define _SHA224_H_
+
+#ifndef _KERNEL
+#include <sys/types.h>
+#endif
+
+#define SHA224_BLOCK_LENGTH		64
+#define SHA224_DIGEST_LENGTH		28
+#define SHA224_DIGEST_STRING_LENGTH	(SHA224_DIGEST_LENGTH * 2 + 1)
+
+typedef struct SHA224Context {
+	uint32_t state[8];
+	uint64_t count;
+	uint8_t buf[SHA224_BLOCK_LENGTH];
+} SHA224_CTX;
+
+__BEGIN_DECLS
+
+void	SHA224_Init(SHA224_CTX *);
+void	SHA224_Update(SHA224_CTX *, const void *, size_t);
+void	SHA224_Final(unsigned char [__min_size(SHA224_DIGEST_LENGTH)],
+    SHA224_CTX *);
+#ifndef _KERNEL
+char   *SHA224_End(SHA224_CTX *, char *);
+char   *SHA224_Data(const void *, unsigned int, char *);
+char   *SHA224_Fd(int, char *);
+char   *SHA224_FdChunk(int, char *, off_t, off_t);
+char   *SHA224_File(const char *, char *);
+char   *SHA224_FileChunk(const char *, char *, off_t, off_t);
+#endif
+__END_DECLS
+
+#endif /* !_SHA224_H_ */
diff --git a/cpukit/libmd/sha256c.c b/cpukit/libmd/sha256c.c
index 197de94586..7fd568a2ab 100644
--- a/cpukit/libmd/sha256c.c
+++ b/cpukit/libmd/sha256c.c
@@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
 
 #include <string.h>
 
+#include "sha224.h"
 #include "sha256.h"
 
 #if BYTE_ORDER == BIG_ENDIAN
@@ -296,3 +297,53 @@ SHA256_Final(unsigned char digest[static SHA256_DIGEST_LENGTH], SHA256_CTX *ctx)
 	/* Clear the context state */
 	memset(ctx, 0, sizeof(*ctx));
 }
+
+/*** SHA-224: *********************************************************/
+/*
+ * the SHA224 and SHA256 transforms are identical
+ */
+
+/* SHA-224 initialization.  Begins a SHA-224 operation. */
+void
+SHA224_Init(SHA224_CTX * ctx)
+{
+
+	/* Zero bits processed so far */
+	ctx->count = 0;
+
+	/* Magic initialization constants */
+	ctx->state[0] = 0xC1059ED8;
+	ctx->state[1] = 0x367CD507;
+	ctx->state[2] = 0x3070DD17;
+	ctx->state[3] = 0xF70E5939;
+	ctx->state[4] = 0xFFC00B31;
+	ctx->state[5] = 0x68581511;
+	ctx->state[6] = 0x64f98FA7;
+	ctx->state[7] = 0xBEFA4FA4;
+}
+
+/* Add bytes into the SHA-224 hash */
+void
+SHA224_Update(SHA224_CTX * ctx, const void *in, size_t len)
+{
+
+	SHA256_Update((SHA256_CTX *)ctx, in, len);
+}
+
+/*
+ * SHA-224 finalization.  Pads the input data, exports the hash value,
+ * and clears the context state.
+ */
+void
+SHA224_Final(unsigned char digest[static SHA224_DIGEST_LENGTH], SHA224_CTX *ctx)
+{
+
+	/* Add padding */
+	SHA256_Pad((SHA256_CTX *)ctx);
+
+	/* Write the hash */
+	be32enc_vect(digest, ctx->state, SHA224_DIGEST_LENGTH);
+
+	/* Clear the context state */
+	explicit_bzero(ctx, sizeof(*ctx));
+}
-- 
2.35.3