From 4da1b8723c1f6fa80345f75135437741cee5f889 Mon Sep 17 00:00:00 2001
From: GabrielTofvesson <gabriel.tofvesson@gmail.com>
Date: Tue, 6 Mar 2018 04:13:31 +0100
Subject: [PATCH] Implemented SHA1

---
 SHA1/SHA1.cpp             | 107 ++++++++++++++++++++++++++++++++++++++
 SHA1/SHA1.h               |  30 +++++++++++
 SHA1/SHA1.vcxproj         |   4 ++
 SHA1/SHA1.vcxproj.filters |  10 ++++
 4 files changed, 151 insertions(+)
 create mode 100644 SHA1/SHA1.cpp
 create mode 100644 SHA1/SHA1.h

diff --git a/SHA1/SHA1.cpp b/SHA1/SHA1.cpp
new file mode 100644
index 0000000..78d5dee
--- /dev/null
+++ b/SHA1/SHA1.cpp
@@ -0,0 +1,107 @@
+#define SHA1_API
+#include "SHA1.h"
+#include <string>
+
+namespace CryptoCPP {
+	namespace SHA1 {
+		SHA1_API char * digest(char * data, size_t data_size)
+		{
+			// Initialize buffers
+			unsigned int h0 = 0x67452301;
+			unsigned int h1 = 0xEFCDAB89;
+			unsigned int h2 = 0x98BADCFE;
+			unsigned int h3 = 0x10325476;
+			unsigned int h4 = 0xC3D2E1F0;
+
+			// Pad message
+			size_t ml = data_size + 1;
+			size_t full_size = ml + ((960 - (ml * 8 % 512)) % 512) / 8 + 8;
+			char * msg = new char[full_size];
+			memcpy(msg, data, data_size);
+			memset(msg + data_size, 0, full_size - data_size);
+			msg[data_size] = 0x80;
+			size_t len = data_size * 8;
+			for (int i = 0; i < 8; ++i) msg[full_size - 1 - i] = (len >> (i * 8)) & 255;
+
+			unsigned int chunks = full_size / 64;
+
+			// Perform hashing for each 512-bit block
+			for (size_t i = 0; i<chunks; ++i)
+			{
+
+				// Split block into words
+				unsigned int * w = new unsigned int[80];
+				for (unsigned int j = 0; j<16; ++j)
+					w[j] |= ((msg[i * 64 + j * 4] << 24) | (msg[i * 64 + j * 4 + 1] << 16) | (msg[i * 64 + j * 4 + 2] << 8) | (msg[i * 64 + j * 4 + 3] << 0));
+
+				// Expand words
+				for (size_t j = 16; j<80; ++j)
+					w[j] = rot(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
+
+				// Initialize chunk-hash
+				unsigned int
+					a = h0,
+					b = h1,
+					c = h2,
+					d = h3,
+					e = h4;
+
+				// Do hash rounds
+				for (size_t t = 0; t<80; ++t)
+				{
+					unsigned int tmp = rot(a, 5) + func(t, b, c, d) + e + K(t) + w[t];
+					e = d;
+					d = c;
+					c = rot(b, 30);
+					b = a;
+					a = tmp;
+				}
+				h0 += a;
+				h1 += b;
+				h2 += c;
+				h3 += d;
+				h4 += e;
+				delete[] w;
+			}
+
+			delete[] msg;
+
+			char * result = new char[20];
+			write_reverse_endian(result, h0, 0);
+			write_reverse_endian(result, h1, 4);
+			write_reverse_endian(result, h2, 8);
+			write_reverse_endian(result, h3, 12);
+			write_reverse_endian(result, h4, 16);
+
+			return result;
+		}
+
+
+		SHA1_API unsigned int func(unsigned int t, unsigned int b, unsigned int c, unsigned int d)
+		{
+			return
+				t < 20 ? (b & c) | ((~b) & d) :
+				t < 40 ? b ^ c ^ d :
+				t < 60 ? (b & c) | (b & d) | (c & d) :
+				/*t<80*/ b ^ c ^ d;
+		}
+
+		SHA1_API unsigned int K(unsigned int t)
+		{
+			return
+				t < 20 ? 0x5A827999 :
+				t < 40 ? 0x6ED9EBA1 :
+				t < 60 ? 0x8F1BBCDC :
+				/*t<80*/ 0xCA62C1D6;
+		}
+
+		SHA1_API unsigned int rot(unsigned int value, size_t by)
+		{
+			return (value << by) | (value >> (32 - by));
+		}
+		SHA1_API void write_reverse_endian(char* to, unsigned int value, size_t offset)
+		{
+			for (size_t t = 0; t < 4; ++t) to[offset + 4 - t] = (value >> (t * 8)) & 255;
+		}
+	}
+}
\ No newline at end of file
diff --git a/SHA1/SHA1.h b/SHA1/SHA1.h
new file mode 100644
index 0000000..61ccf34
--- /dev/null
+++ b/SHA1/SHA1.h
@@ -0,0 +1,30 @@
+#pragma once
+
+#if defined(__MINGW32__) || defined(_WIN32)
+
+#if defined(SHA1_API)
+#undef SHA1_API
+#define SHA1_API __declspec(dllexport)
+#else
+#define SHA1_API __declspec(dllimport)
+#endif
+
+#endif
+
+#ifndef SHA1_API
+#if __GNUC__ >= 4
+#define SHA1_API __attribute__ ((visibility ("default")))
+#else
+#define SHA1_API
+#endif
+#endif
+
+namespace CryptoCPP {
+	namespace SHA {
+		SHA1_API char * digest(char * data, size_t data_size);
+		SHA1_API unsigned int rot(unsigned int val, size_t by);
+		SHA1_API unsigned int func(unsigned int t, unsigned int b, unsigned int c, unsigned int d);
+		SHA1_API unsigned int K(unsigned int t);
+		SHA1_API void write_reverse_endian(char* to, unsigned int value, size_t offset);
+	}
+}
\ No newline at end of file
diff --git a/SHA1/SHA1.vcxproj b/SHA1/SHA1.vcxproj
index e7e53dc..051156e 100644
--- a/SHA1/SHA1.vcxproj
+++ b/SHA1/SHA1.vcxproj
@@ -116,6 +116,10 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClInclude Include="SHA1.h" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="SHA1.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
diff --git a/SHA1/SHA1.vcxproj.filters b/SHA1/SHA1.vcxproj.filters
index 6a1782f..f7cac3d 100644
--- a/SHA1/SHA1.vcxproj.filters
+++ b/SHA1/SHA1.vcxproj.filters
@@ -14,4 +14,14 @@
       <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
     </Filter>
   </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="SHA1.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="SHA1.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+  </ItemGroup>
 </Project>
\ No newline at end of file