Tools to compute UnixFS IPFS hash.

Author: chriseth

libdevcore/CMakeLists.txt

@@ -12,10 +12,13 @@ set(sources
 	FixedHash.h
 	IndentedWriter.cpp
 	IndentedWriter.h
+	IpfsHash.cpp
+	IpfsHash.h
 	JSON.cpp
 	JSON.h
 	Keccak256.cpp
 	Keccak256.h
+	picosha2.h
 	Result.h
 	StringUtils.cpp
 	StringUtils.h

libdevcore/picosha2.h

@@ -0,0 +1,288 @@
+/*
+The MIT License (MIT)
+
+Copyright (C) 2014 okdshin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+#pragma once
+
+//picosha2:20140213
+#include <cstdint>
+#include <iostream>
+#include <vector>
+#include <iterator>
+#include <cassert>
+#include <sstream>
+#include <algorithm>
+
+namespace picosha2
+{
+
+namespace detail
+{
+
+inline uint8_t mask_8bit(uint8_t x)
+{
+	return x&0xff;
+}
+
+inline uint32_t mask_32bit(uint32_t x)
+{
+	return x&0xffffffff;
+}
+
+static const uint32_t add_constant[64] = {
+	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
+};
+
+static const uint32_t initial_message_digest[8] = {
+	0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+	0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
+};
+
+inline uint32_t ch(uint32_t x, uint32_t y, uint32_t z)
+{
+	return (x&y)^((~x)&z);
+}
+
+inline uint32_t maj(uint32_t x, uint32_t y, uint32_t z)
+{
+	return (x&y)^(x&z)^(y&z);
+}
+
+inline uint32_t rotr(uint32_t x, std::size_t n)
+{
+	assert(n < 32);
+	return mask_32bit((x>>n)|(x<<(32-n)));
+}
+
+inline uint32_t bsig0(uint32_t x)
+{
+	return rotr(x, 2)^rotr(x, 13)^rotr(x, 22);
+}
+
+inline uint32_t bsig1(uint32_t x)
+{
+	return rotr(x, 6)^rotr(x, 11)^rotr(x, 25);
+}
+
+inline uint32_t shr(uint32_t x, std::size_t n)
+{
+	assert(n < 32);
+	return x >> n;
+}
+
+inline uint32_t ssig0(uint32_t x)
+{
+	return rotr(x, 7)^rotr(x, 18)^shr(x, 3);
+}
+
+inline uint32_t ssig1(uint32_t x)
+{
+	return rotr(x, 17)^rotr(x, 19)^shr(x, 10);
+}
+
+template<typename RaIter1, typename RaIter2>
+void hash256_block(RaIter1 message_digest, RaIter2 first, RaIter2 last)
+{
+	(void)last; // FIXME: check this is valid
+	uint32_t w[64];
+	std::fill(w, w+64, 0);
+	for (std::size_t i = 0; i < 16; ++i)
+		w[i] = (static_cast<uint32_t>(mask_8bit(*(first+i*4)))<<24)
+			|(static_cast<uint32_t>(mask_8bit(*(first+i*4+1)))<<16)
+			|(static_cast<uint32_t>(mask_8bit(*(first+i*4+2)))<<8)
+			|(static_cast<uint32_t>(mask_8bit(*(first+i*4+3))));
+	for (std::size_t i = 16; i < 64; ++i)
+		w[i] = mask_32bit(ssig1(w[i-2])+w[i-7]+ssig0(w[i-15])+w[i-16]);
+	
+	uint32_t a = *message_digest;
+	uint32_t b = *(message_digest+1);
+	uint32_t c = *(message_digest+2);
+	uint32_t d = *(message_digest+3);
+	uint32_t e = *(message_digest+4);
+	uint32_t f = *(message_digest+5);
+	uint32_t g = *(message_digest+6);
+	uint32_t h = *(message_digest+7);
+	
+	for (std::size_t i = 0; i < 64; ++i)
+	{
+		uint32_t temp1 = h+bsig1(e)+ch(e,f,g)+add_constant[i]+w[i];
+		uint32_t temp2 = bsig0(a)+maj(a,b,c);
+		h = g;
+		g = f;
+		f = e;
+		e = mask_32bit(d+temp1);
+		d = c;
+		c = b;
+		b = a;
+		a = mask_32bit(temp1+temp2);
+	}
+	*message_digest += a;
+	*(message_digest+1) += b;
+	*(message_digest+2) += c;
+	*(message_digest+3) += d;
+	*(message_digest+4) += e;
+	*(message_digest+5) += f;
+	*(message_digest+6) += g;
+	*(message_digest+7) += h;
+	for (std::size_t i = 0; i < 8; ++i)
+		*(message_digest+i) = mask_32bit(*(message_digest+i));
+}
+
+}//namespace detail
+
+class hash256_one_by_one
+{
+public:
+	hash256_one_by_one()
+	{
+		init();
+	}
+
+	void init()
+	{
+		buffer_.clear();
+		std::fill(data_length_digits_, data_length_digits_+4, 0);
+		std::copy(detail::initial_message_digest, detail::initial_message_digest+8, h_);
+	}
+
+	template<typename RaIter>
+	void process(RaIter first, RaIter last)
+	{
+		add_to_data_length(std::distance(first, last));
+		std::copy(first, last, std::back_inserter(buffer_));
+		std::size_t i = 0;
+		for (;i+64 <= buffer_.size(); i+=64)
+			detail::hash256_block(h_, buffer_.begin()+i, buffer_.begin()+i+64);	
+		buffer_.erase(buffer_.begin(), buffer_.begin()+i);
+	}
+
+	void finish()
+	{
+		uint8_t temp[64];
+		std::fill(temp, temp+64, 0);
+		std::size_t remains = buffer_.size();
+		std::copy(buffer_.begin(), buffer_.end(), temp);
+		temp[remains] = 0x80;
+
+		if(remains > 55)
+		{
+			std::fill(temp+remains+1, temp+64, 0);
+			detail::hash256_block(h_, temp, temp+64);
+			std::fill(temp, temp+64-4, 0);
+		}
+		else
+			std::fill(temp+remains+1, temp+64-4, 0);
+
+		write_data_bit_length(&(temp[56]));
+		detail::hash256_block(h_, temp, temp+64);
+	}
+
+	template<typename OutIter>
+	void get_hash_bytes(OutIter first, OutIter last) const
+	{
+		for (const uint32_t* iter = h_; iter != h_+8; ++iter)
+			for (std::size_t i = 0; i < 4 && first != last; ++i)
+				*(first++) = detail::mask_8bit(static_cast<uint8_t>((*iter >> (24-8*i))));
+	}
+
+private:
+	void add_to_data_length(uint32_t n)
+	{
+		uint32_t carry = 0;
+		data_length_digits_[0] += n;
+		for (std::size_t i = 0; i < 4; ++i)
+		{
+			data_length_digits_[i] += carry;
+			if(data_length_digits_[i] >= 65536u)
+			{
+				data_length_digits_[i] -= 65536u;
+				carry = 1;
+			}
+			else
+				break;
+		}
+	}
+	void write_data_bit_length(uint8_t* begin)
+	{
+		uint32_t data_bit_length_digits[4];
+		std::copy(
+			data_length_digits_, data_length_digits_+4,
+			data_bit_length_digits
+		);
+
+		// convert byte length to bit length (multiply 8 or shift 3 times left)
+		uint32_t carry = 0;
+		for (std::size_t i = 0; i < 4; ++i)
+		{
+			uint32_t before_val = data_bit_length_digits[i];
+			data_bit_length_digits[i] <<= 3;
+			data_bit_length_digits[i] |= carry;
+			data_bit_length_digits[i] &= 65535u;
+			carry = (before_val >> (16-3)) & 65535u;
+		}
+
+		// write data_bit_length
+		for (int i = 3; i >= 0; --i)
+		{
+			(*begin++) = static_cast<uint8_t>(data_bit_length_digits[i] >> 8);
+			(*begin++) = static_cast<uint8_t>(data_bit_length_digits[i]);
+		}
+	}
+	std::vector<uint8_t> buffer_;
+	uint32_t data_length_digits_[4]; //as 64bit integer (16bit x 4 integer)
+	uint32_t h_[8];
+};
+
+template<typename RaIter, typename OutIter>
+void hash256(RaIter first, RaIter last, OutIter first2, OutIter last2)
+{
+	hash256_one_by_one hasher;
+	//hasher.init();
+	hasher.process(first, last);
+	hasher.finish();
+	hasher.get_hash_bytes(first2, last2);
+}
+
+template <typename RaContainer>
+std::vector<uint8_t> hash256(RaContainer const& _src)
+{
+	std::vector<uint8_t> ret(32);
+	hash256(_src.begin(), _src.end(), ret.begin(), ret.end());
+	return ret;
+}
+
+}//namespace picosha2