From 6511a62c3cec0a64bbdd7ac8e3588d39c164af09 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 16 Apr 2016 13:59:38 +0300
Subject: [PATCH] Implement the SHA2 hash family

---
 source/blockhash.h |  68 +++++++++++++++
 source/sha2.cpp    | 203 +++++++++++++++++++++++++++++++++++++++++++++
 source/sha2.h      |  77 +++++++++++++++++
 3 files changed, 348 insertions(+)
 create mode 100644 source/blockhash.h
 create mode 100644 source/sha2.cpp
 create mode 100644 source/sha2.h

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
diff --git a/source/sha2.cpp b/source/sha2.cpp
new file mode 100644
index 0000000..2451442
--- /dev/null
+++ b/source/sha2.cpp
@@ -0,0 +1,203 @@
+#include <stdexcept>
+#include "sha2.h"
+
+using namespace std;
+
+namespace {
+
+template<typename T>
+inline T read_word(const char *data)
+{
+	const Msp::UInt8 *u8data = reinterpret_cast<const Msp::UInt8 *>(data);
+	T result = 0;
+	for(unsigned i=0; i<sizeof(T); ++i)
+		result |= static_cast<T>(u8data[i])<<((sizeof(T)-1-i)*8);
+	return result;
+}
+
+template<typename T>
+inline void write_word(T w, char *buf)
+{
+	for(unsigned i=0; i<sizeof(T); ++i)
+		buf[i] = w>>((sizeof(T)-1-i)*8);
+}
+
+template<typename T>
+inline T rotate_right(T x, unsigned b)
+{
+	return (x>>b) | (x<<(sizeof(T)*8-b));
+}
+
+}
+
+
+namespace Msp {
+namespace Crypto {
+
+template<typename C>
+SHA2<C>::SHA2()
+{
+	init();
+}
+template SHA2<SHA2_256Constants>::SHA2();
+template SHA2<SHA2_512Constants>::SHA2();
+
+template<typename C>
+SHA2<C>::SHA2(const char *data, unsigned len)
+{
+	init();
+	BlockHash<Constants::BLOCK_SIZE>::update(data, len);
+}
+template SHA2<SHA2_256Constants>::SHA2(const char *, unsigned);
+template SHA2<SHA2_512Constants>::SHA2(const char *, unsigned);
+
+template<typename C>
+SHA2<C>::SHA2(const string &str)
+{
+	init();
+	BlockHash<Constants::BLOCK_SIZE>::update(str);
+}
+template SHA2<SHA2_256Constants>::SHA2(const string &);
+template SHA2<SHA2_512Constants>::SHA2(const string &);
+
+template<typename C>
+void SHA2<C>::init()
+{
+	copy(Constants::initial, Constants::initial+8, buffer);
+	processed_bytes = 0;
+}
+template void SHA2<SHA2_256Constants>::init();
+template void SHA2<SHA2_512Constants>::init();
+
+template<typename C>
+void SHA2<C>::process_block(const char *data)
+{
+	WordType message_blocks[Constants::N_ROUNDS];
+	for(unsigned i=0; i<Constants::BLOCK_SIZE/Constants::WORD_SIZE; ++i)
+		message_blocks[i] = read_word<WordType>(data+i*Constants::WORD_SIZE);
+	const unsigned *const sigma = Constants::sigma_constants;
+	for(unsigned i=16; i<Constants::N_ROUNDS; ++i)
+	{
+		WordType *block = message_blocks+i;
+		WordType s1 = (rotate_right(block[-2], sigma[9]) ^ rotate_right(block[-2], sigma[10]) ^ (block[-2]>>sigma[11]));
+		WordType s0 = (rotate_right(block[-15], sigma[6]) ^ rotate_right(block[-15], sigma[7]) ^ (block[-15]>>sigma[8]));
+		*block =  s1+block[-7]+s0+block[-16];
+	}
+
+	WordType values[8];
+	copy(buffer, buffer+8, values);
+
+	for(unsigned i=0; i<Constants::N_ROUNDS; ++i)
+	{
+		WordType s1 = (rotate_right(values[4], sigma[3]) ^ rotate_right(values[4], sigma[4]) ^ rotate_right(values[4], sigma[5]));
+		WordType ch = ((values[4]&values[5]) ^ (~values[4]&values[6]));
+		WordType temp1 = values[7]+s1+ch+Constants::round_constants[i]+message_blocks[i];
+		WordType s0 = (rotate_right(values[0], sigma[0]) ^ rotate_right(values[0], sigma[1]) ^ rotate_right(values[0], sigma[2]));
+		WordType maj = ((values[0]&values[1]) ^ (values[0]&values[2]) ^ (values[1]&values[2]));
+		WordType temp2 = s0+maj;
+		values[7] = values[6];
+		values[6] = values[5];
+		values[5] = values[4];
+		values[4] = values[3]+temp1;
+		values[3] = values[2];
+		values[2] = values[1];
+		values[1] = values[0];
+		values[0] = temp1+temp2;
+	}
+
+	for(unsigned i=0; i<8; ++i)
+		buffer[i] += values[i];
+
+	processed_bytes += Constants::BLOCK_SIZE;
+}
+template void SHA2<SHA2_256Constants>::process_block(const char *);
+template void SHA2<SHA2_512Constants>::process_block(const char *);
+
+template<typename C>
+unsigned SHA2<C>::get_digest(char *digest, unsigned len) const
+{
+	if(len<Constants::DIGEST_SIZE)
+		throw invalid_argument("SHA2::get_digest");
+
+	SHA2<Constants> padded = *this;
+
+	char padding[Constants::BLOCK_SIZE] = { static_cast<char>(0x80) };
+	padded.update(padding, Constants::BLOCK_SIZE-(this->unprocessed_bytes+8)%Constants::BLOCK_SIZE);
+
+	UInt64 message_length = (processed_bytes+this->unprocessed_bytes)*8;
+	write_word(message_length, padding);
+	padded.update(padding, 8);
+
+	for(unsigned i=0; i<8; ++i)
+		write_word(padded.buffer[i], digest+i*Constants::WORD_SIZE);
+
+	return Constants::DIGEST_SIZE;
+}
+template unsigned SHA2<SHA2_256Constants>::get_digest(char *, unsigned) const;
+template unsigned SHA2<SHA2_512Constants>::get_digest(char *, unsigned) const;
+
+
+const SHA2_256Constants::WordType SHA2_256Constants::initial[8] =
+{
+	0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
+};
+
+const SHA2_256Constants::WordType SHA2_256Constants::round_constants[SHA2_256Constants::N_ROUNDS] =
+{
+	0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5,
+	0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174,
+	0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
+	0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967,
+	0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85,
+	0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
+	0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3,
+	0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2
+};
+
+const unsigned SHA2_256Constants::sigma_constants[12] =
+{
+	2, 13, 22,  // For Σ₀
+	6, 11, 25,  // For Σ₁
+	7, 18, 3,   // For σ₀
+	17, 19, 10  // For σ₁
+};
+
+const SHA2_512Constants::WordType SHA2_512Constants::initial[8] =
+{
+	0x6A09E667F3BCC908, 0xBB67AE8584CAA73B, 0x3C6EF372FE94F82B, 0xA54FF53A5F1D36F1,
+	0x510E527FADE682D1, 0x9B05688C2B3E6C1F, 0x1F83D9ABFB41BD6B, 0x5BE0CD19137E2179,
+};
+
+const SHA2_512Constants::WordType SHA2_512Constants::round_constants[SHA2_512Constants::N_ROUNDS] =
+{
+	0x428A2F98D728AE22, 0x7137449123EF65CD, 0xB5C0FBCFEC4D3B2F, 0xE9B5DBA58189DBBC,
+	0x3956C25BF348B538, 0x59F111F1B605D019, 0x923F82A4AF194F9B, 0xAB1C5ED5DA6D8118,
+	0xD807AA98A3030242, 0x12835B0145706FBE, 0x243185BE4EE4B28C, 0x550C7DC3D5FFB4E2,
+	0x72BE5D74F27B896F, 0x80DEB1FE3B1696B1, 0x9BDC06A725C71235, 0xC19BF174CF692694,
+	0xE49B69C19EF14AD2, 0xEFBE4786384F25E3, 0x0FC19DC68B8CD5B5, 0x240CA1CC77AC9C65,
+	0x2DE92C6F592B0275, 0x4A7484AA6EA6E483, 0x5CB0A9DCBD41FBD4, 0x76F988DA831153B5,
+	0x983E5152EE66DFAB, 0xA831C66D2DB43210, 0xB00327C898FB213F, 0xBF597FC7BEEF0EE4,
+	0xC6E00BF33DA88FC2, 0xD5A79147930AA725, 0x06CA6351E003826F, 0x142929670A0E6E70,
+	0x27B70A8546D22FFC, 0x2E1B21385C26C926, 0x4D2C6DFC5AC42AED, 0x53380D139D95B3DF,
+	0x650A73548BAF63DE, 0x766A0ABB3C77B2A8, 0x81C2C92E47EDAEE6, 0x92722C851482353B,
+	0xA2BFE8A14CF10364, 0xA81A664BBC423001, 0xC24B8B70D0F89791, 0xC76C51A30654BE30,
+	0xD192E819D6EF5218, 0xD69906245565A910, 0xF40E35855771202A, 0x106AA07032BBD1B8,
+	0x19A4C116B8D2D0C8, 0x1E376C085141AB53, 0x2748774CDF8EEB99, 0x34B0BCB5E19B48A8,
+	0x391C0CB3C5C95A63, 0x4ED8AA4AE3418ACB, 0x5B9CCA4F7763E373, 0x682E6FF3D6B2B8A3,
+	0x748F82EE5DEFB2FC, 0x78A5636F43172F60, 0x84C87814A1F0AB72, 0x8CC702081A6439EC,
+	0x90BEFFFA23631E28, 0xA4506CEBDE82BDE9, 0xBEF9A3F7B2C67915, 0xC67178F2E372532B,
+	0xCA273ECEEA26619C, 0xD186B8C721C0C207, 0xEADA7DD6CDE0EB1E, 0xF57D4F7FEE6ED178,
+	0x06F067AA72176FBA, 0x0A637DC5A2C898A6, 0x113F9804BEF90DAE, 0x1B710B35131C471B,
+	0x28DB77F523047D84, 0x32CAAB7B40C72493, 0x3C9EBE0A15C9BEBC, 0x431D67C49C100D4C,
+	0x4CC5D4BECB3E42B6, 0x597F299CFC657E2A, 0x5FCB6FAB3AD6FAEC, 0x6C44198C4A475817
+};
+const unsigned SHA2_512Constants::sigma_constants[12] =
+{
+	28, 34, 39,  // For Σ₀
+	14, 18, 41,  // For Σ₁
+	1, 8, 7,     // For σ₀
+	19, 61, 6    // For σ₁
+};
+
+} // namespace Crypto
+} // namespace Msp
diff --git a/source/sha2.h b/source/sha2.h
new file mode 100644
index 0000000..ed5c4fe
--- /dev/null
+++ b/source/sha2.h
@@ -0,0 +1,77 @@
+#ifndef MSP_CRYPTO_SHA2_H_
+#define MSP_CRYPTO_SHA2_H_
+
+#include <msp/core/inttypes.h>
+#include "blockhash.h"
+
+namespace Msp {
+namespace Crypto {
+
+template<typename C>
+class SHA2: public BlockHash<C::BLOCK_SIZE>
+{
+private:
+	typedef C Constants;
+	typedef typename Constants::WordType WordType;
+
+	typename Constants::WordType buffer[8];
+	UInt64 processed_bytes;
+
+public:
+	SHA2();
+	SHA2(const char *, unsigned);
+	SHA2(const std::string &);
+private:
+	void init();
+
+public:
+	virtual unsigned get_digest_size() const { return Constants::DIGEST_SIZE; }
+
+	virtual unsigned get_digest(char *, unsigned) const;
+
+private:
+	virtual void process_block(const char *);
+};
+
+
+struct SHA2_256Constants
+{
+	typedef UInt32 WordType;
+
+	enum
+	{
+		WORD_SIZE = sizeof(WordType),
+		BLOCK_SIZE = 64,   // 512 bits
+		DIGEST_SIZE = 32,  // 256 bits
+		N_ROUNDS = 64
+	};
+
+	static const WordType initial[8];
+	static const WordType round_constants[N_ROUNDS];
+	static const unsigned sigma_constants[12];
+};
+
+struct SHA2_512Constants
+{
+	typedef UInt64 WordType;
+
+	enum
+	{
+		WORD_SIZE = sizeof(WordType),
+		BLOCK_SIZE = 128,  // 1024 bits
+		DIGEST_SIZE = 64,  // 512 bits
+		N_ROUNDS = 80
+	};
+
+	static const WordType initial[8];
+	static const WordType round_constants[N_ROUNDS];
+	static const unsigned sigma_constants[12];
+};
+
+typedef SHA2<SHA2_256Constants> SHA256;
+typedef SHA2<SHA2_512Constants> SHA512;
+
+} // namespace Crypto
+} // namespace Msp
+
+#endif
-- 
2.43.0