X-Git-Url: http://git.tdb.fi/?p=libs%2Fcrypto.git;a=blobdiff_plain;f=source%2Fblockhash.h;fp=source%2Fblockhash.h;h=309fbfac86593c01a0a321c66a1762f42c7b0dfd;hp=0000000000000000000000000000000000000000;hb=6511a62c3cec0a64bbdd7ac8e3588d39c164af09;hpb=cb6ee39a05f6903a0ef521c81e6f42d05289b1a1

diff --git a/source/blockhash.h b/source/blockhash.h
new file mode 100644
index 0000000..309fbfa
--- /dev/null
+++ b/source/blockhash.h
@@ -0,0 +1,68 @@
+#ifndef MSP_CRYPTO_BLOCKHASH_H_
+#define MSP_CRYPTO_BLOCKHASH_H_
+
+#include <algorithm>
+#include "hash.h"
+
+namespace Msp {
+namespace Crypto {
+
+template<unsigned B>
+class BlockHash: public Hash
+{
+protected:
+	enum
+	{
+		BLOCK_SIZE = B
+	};
+
+	char unprocessed[BLOCK_SIZE];
+	unsigned unprocessed_bytes;
+
+	BlockHash();
+
+public:
+	using Hash::update;
+	virtual void update(const char *, unsigned);
+
+protected:
+	virtual void process_block(const char *) = 0;
+};
+
+
+template<unsigned B>
+inline BlockHash<B>::BlockHash():
+	unprocessed_bytes(0)
+{ }
+
+template<unsigned B>
+void BlockHash<B>::update(const char *data, unsigned len)
+{
+	if(unprocessed_bytes && unprocessed_bytes+len>=BLOCK_SIZE)
+	{
+		unsigned needed = BLOCK_SIZE-unprocessed_bytes;
+		std::copy(data, data+needed, unprocessed+unprocessed_bytes);
+		process_block(unprocessed);
+		data += needed;
+		len -= needed;
+		unprocessed_bytes = 0;
+	}
+
+	while(len>=BLOCK_SIZE)
+	{
+		process_block(data);
+		data += BLOCK_SIZE;
+		len -= BLOCK_SIZE;
+	}
+
+	if(len>0)
+	{
+		std::copy(data, data+len, unprocessed+unprocessed_bytes);
+		unprocessed_bytes += len;
+	}
+}
+
+} // namespace Crypto
+} // namespace Msp
+
+#endif