Merge pull request 'Hauptimplementierung' (#4) from feat/main-implementation into master

Reviewed-on: https://gitlab-gepasp.in.tum.de/gra22s/team199/pulls/4
Reviewed-by: Thomas Florian <thomas.florian@tum.de>

.gitignore

@@ -1 +0,0 @@
-build

.vscode/extensions.json

@@ -1,6 +1,5 @@
 {
     "recommendations": [
-        "ms-vscode.cpptools",
+        "ms-vscode.cpptools"
-        "twxs.cmake"
     ]
 }

.vscode/launch.json

@@ -0,0 +1,29 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "cppdbg",
+            "request": "launch",
+            "name": "C/C++: gcc debug active file",
+            "program": "${workspaceFolder}/Implementierung/md2",
+            "args": [
+                "${workspaceFolder}/Implementierung/testfile"
+            ],
+            "cwd": "${workspaceFolder}",
+            "externalConsole": false,
+            "MIMode": "gdb",
+            "setupCommands": [
+                {
+                    "description": "Enable pretty-printing for gdb",
+                    "text": "-enable-pretty-printing",
+                    "ignoreFailures": true
+                }
+            ],
+            "preLaunchTask": "C/C++: gcc build active file",
+            "miDebuggerPath": "/usr/bin/gdb"
+        }
+    ]
+}

.vscode/settings.json

@@ -2,8 +2,22 @@
   "C_Cpp.clang_format_fallbackStyle": "Google",
   "files.associations": {
     "functional": "c",
-    "helper.h": "c"
+    "helper.h": "c",
+    "string": "c",
+    "vector": "c",
+    "memory": "c",
+    "optional": "c",
+    "string_view": "c",
+    "system_error": "c",
+    "variant": "c",
+    "array": "c",
+    "md2.h": "c",
+    "io.h": "c"
   },
   "editor.formatOnSave": true,
-  "cmake.sourceDirectory": "${workspaceFolder}/Implementierung"
+  "C_Cpp.default.includePath": [
-}
+    "./lib",
+    "./Implementierung/lib",
+    "../lib"
+  ]
+}

.vscode/tasks.json

@@ -7,9 +7,9 @@
             "args": [
                 "-fdiagnostics-color=always",
                 "-g",
-                "${file}",
+                "${fileDirname}/*.c",
                 "-o",
-                "${fileDirname}/${fileBasenameNoExtension}"
+                "${fileDirname}/../md2"
             ],
             "options": {
                 "cwd": "${fileDirname}"

Ausarbeitung/Ausarbeitung.tex

@@ -4,10 +4,10 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% TODO: Ersetzen Sie in den folgenden Zeilen die entsprechenden -Texte-
 %% mit den richtigen Werten.
-\newcommand{\theGroup}{IhreGruppennummer} % Beispiel: 42
+\newcommand{\theGroup}{199} % Beispiel: 42
-\newcommand{\theNumber}{IhreProjektnummer} % Beispiel: A123
+\newcommand{\theNumber}{A505} % Beispiel: A123
-\author{Vorname1 Nachname1 \and Vorname2 Nachname2 \and Vorname3 Nachname3}
+\author{Dorian Zedler \and Finn Dröge \and Thomas Florian}
-\date{AktuellesSemester} % Beispiel: Wintersemester 2019/20
+\date{Sommersemester 2022} % Beispiel: Wintersemester 2019/20
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 % Diese Zeile bitte -nicht- aendern.

Implementierung/.gitignore

@@ -1,5 +1,2 @@
-Makefile
+build
-cmake_install.cmake
+md2
-CMakeCache.txt
-md2
-CMakeFiles

Implementierung/CMakeLists.txt

@@ -1,19 +0,0 @@
-cmake_minimum_required(VERSION 3.0.0)
-
-# here we specify that the project is C language only, so the default
-# C compiler on the system will be used
-project(md2 C)
-add_executable(md2 "")
-
-set(SOURCE_FILES
-    src/main.c
-    src/helper.c
-    src/io.c
-    src/md2.c
-)
-
-target_sources(md2 PRIVATE ${SOURCE_FILES})
-
-target_include_directories(md2 PUBLIC
-    lib
-)

Implementierung/Makefile

@@ -0,0 +1,32 @@
+
+
+SRC = src/main.c src/helper.c src/io.c src/md2.c
+OBJ = ${subst src,build,${SRC:.c=.o}}
+CC = gcc
+CFLAGS = -Ilib -ggdb
+LDFLAGS = 
+
+all: md2
+
+clean:
+	rm -rf md2 build
+
+help:
+	@echo === Project Build Help ===
+	@echo
+	@echo Available targets:
+	@echo - all: build everything
+	@echo - clean: clean distfiles
+	@echo - help: show this help
+
+build:
+	mkdir build
+
+build/%.o: src/%.c
+	@mkdir -p build
+	${CC} -c ${CFLAGS} -o $@ $<
+
+md2: ${OBJ} 
+	${CC} -o $@ $(OBJ) ${LDFLAGS}
+
+.PHONY: all clean help

Implementierung/lib/io.h

@@ -1,7 +1,10 @@
 #ifndef IO_H
 #define IO_H
 
+#define _XOPEN_SOURCE
+
 #include <errno.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -12,8 +15,8 @@
  *
  * @param path the filepath
  * @param size a pointer where the size of the result should be stored
- * @return the raw data
+ * @return pointer to the raw data or NULL on errors
  */
-static uint8_t* read_file(const char* path, size_t* size);
+uint8_t* read_file(const char* path, size_t* size);
 
 #endif  // IO_H

Implementierung/lib/md2.h

@@ -2,6 +2,9 @@
 #define MD2_H
 
 #include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/types.h>
 
 /**
@@ -22,4 +25,12 @@ void md2_hash(size_t len, const uint8_t buf[], uint8_t out[16]);
  */
 void md2_checksum(size_t len, uint8_t* buf);
 
+/**
+ * @brief Takes a uint8_t array and converts it into a string
+ *
+ * @param hash the array containing the hash
+ * @param stringHash pointer to store the string, has to have 32 bytes space
+ */
+void encodeHash(uint8_t hash[16], char* stringHash);
+
 #endif  // MD2_H

Implementierung/src/helper.c

@@ -1,4 +1,4 @@
-#include "helper.h"
+#include "../lib/helper.h"
 
 int stringToInt(char *string) {
   char *leftover = "";

Implementierung/src/io.c

@@ -1,6 +1,6 @@
-#include "io.h"
+#include "../lib/io.h"
 
-static uint8_t* read_file(const char* path, size_t* size) {
+uint8_t* read_file(const char* path, size_t* size) {
   // Read the contents of the file specified by path into a heap-allocated
   // buffer and return a pointer to that buffer.
   FILE* f = fopen(path, "r");
@@ -28,7 +28,7 @@ static uint8_t* read_file(const char* path, size_t* size) {
 
   size_t bytesRead =
       fread(data, statOfFile.st_blksize, statOfFile.st_blocks, f);
-  // Or: size_t bytesRead = fread(data, sizeof(char), statOfFile.st_size, f);
+  // size_t bytesRead = fread(data, sizeof(uint8_t), statOfFile.st_size, f);
   if (bytesRead != 0 && !feof(f)) {
     printf("Error reading file!\n");
     fclose(f);
@@ -37,6 +37,6 @@ static uint8_t* read_file(const char* path, size_t* size) {
 
   fclose(f);
 
-  (*size) = bytesRead;
+  (*size) = statOfFile.st_size;
   return data;
 }

Implementierung/src/main.c

@@ -1,6 +1,51 @@
-#include "helper.h"
+#include <stdbool.h>
-#include "io.h"
+
-#include "md2.h"
+#include "../lib/helper.h"
+#include "../lib/io.h"
+#include "../lib/md2.h"
+
+// Returns true when val is approx. equal to exp.
+static bool runTest(const char* message, const char* expectedHash) {
+  uint8_t out[16];
+  md2_hash(strlen(message), message, out);
+
+  char hash[32];
+  encodeHash(out, hash);
+
+  bool ok = !strcmp(hash, expectedHash);
+  printf("%s: md2(%s) %s == %s\n", "not ok" + (4 * ok), message, hash,
+         expectedHash);
+  return ok;
+}
+
+unsigned runTests(void) {
+  unsigned failed = 0;
+  // Note: cases with n<2 are not tested here.
+  failed += !runTest("", "8350e5a3e24c153df2275c9f80692773");
+  failed += !runTest("a", "32ec01ec4a6dac72c0ab96fb34c0b5d1");
+  failed += !runTest("abc", "da853b0d3f88d99b30283a69e6ded6bb");
+  failed += !runTest("message digest", "ab4f496bfb2a530b219ff33031fe06b0");
+  failed += !runTest("jebdjcslfhwfdig", "e1b69085c6f6e36cb8fe8d98ed3f2c35");
+  failed += !runTest("0123456789abcde", "d95629645108a20ab4d70e8545e0723b");
+  failed += !runTest("0123456789abcdef", "12c8dfa285f14e1af8c5254e7092d0d3");
+  failed += !runTest("0123456789abcdefg", "e4d0efded5ef7b6843a5ba47e1171347");
+  failed += !runTest("abcdefghijklmnopqrstuvwxyz",
+                     "4e8ddff3650292ab5a4108c3aa47940b");
+  failed +=
+      !runTest("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
+               "da33def2a42df13975352846c30338cd");
+  failed += !runTest(
+      "123456789012345678901234567890123456789012345678901234567890123456789012"
+      "34567890",
+      "d5976f79d83d3a0dc9806c3c66f3efd8");
+
+  if (failed)
+    printf("%u tests FAILED\n", failed);
+  else
+    printf("All tests PASSED\n");
+
+  return failed;
+}
 
 int main(int argc, char** argv) {
   struct configuration c;
@@ -20,5 +65,26 @@ int main(int argc, char** argv) {
       "benchmark cycles: %d\n",
       c.filename, c.implementationToUse, c.doBenchmark, c.benchmarkingCycles);
 
+  // runTests();
+  size_t len;
+  uint8_t* data = read_file(c.filename, &len);
+  if (data == NULL) {
+    printf("Error reading file %s!", c.filename);
+    return EXIT_FAILURE;
+  }
+
+  printf("File read with size: %zu\n", len);
+  printf("\n");
+
+  uint8_t out[16];
+  md2_hash(len, data, out);
+
+  printf("Hash: ");
+  char hash[32];
+  encodeHash(out, hash);
+  printf("%s\n", hash);
+
+  free(data);
+
   return 0;
 }

Implementierung/src/md2.c

@@ -1,8 +1,107 @@
-#include "io.h"
+#include "../lib/md2.h"
 
 // The file "testfile" should lead to this hash:
 // fc982e558db259f298b43cd4c1241c66
 
-void md2_checksum(size_t len, uint8_t* buf) {}
+// Source: https://datatracker.ietf.org/doc/html/rfc1319
+static unsigned char PI_SUBST[256] = {
+    41,  46,  67,  201, 162, 216, 124, 1,   61,  54,  84,  161, 236, 240, 6,
+    19,  98,  167, 5,   243, 192, 199, 115, 140, 152, 147, 43,  217, 188, 76,
+    130, 202, 30,  155, 87,  60,  253, 212, 224, 22,  103, 66,  111, 24,  138,
+    23,  229, 18,  190, 78,  196, 214, 218, 158, 222, 73,  160, 251, 245, 142,
+    187, 47,  238, 122, 169, 104, 121, 145, 21,  178, 7,   63,  148, 194, 16,
+    137, 11,  34,  95,  33,  128, 127, 93,  154, 90,  144, 50,  39,  53,  62,
+    204, 231, 191, 247, 151, 3,   255, 25,  48,  179, 72,  165, 181, 209, 215,
+    94,  146, 42,  172, 86,  170, 198, 79,  184, 56,  210, 150, 164, 125, 182,
+    118, 252, 107, 226, 156, 116, 4,   241, 69,  157, 112, 89,  100, 113, 135,
+    32,  134, 91,  207, 101, 230, 45,  168, 2,   27,  96,  37,  173, 174, 176,
+    185, 246, 28,  70,  97,  105, 52,  64,  126, 15,  85,  71,  163, 35,  221,
+    81,  175, 58,  195, 92,  249, 206, 186, 197, 234, 38,  44,  83,  13,  110,
+    133, 40,  132, 9,   211, 223, 205, 244, 65,  129, 77,  82,  106, 220, 55,
+    200, 108, 193, 171, 250, 36,  225, 123, 8,   12,  189, 177, 74,  120, 136,
+    149, 139, 227, 99,  232, 109, 233, 203, 213, 254, 59,  0,   29,  57,  242,
+    239, 183, 14,  102, 88,  208, 228, 166, 119, 114, 248, 235, 117, 75,  10,
+    49,  68,  80,  180, 143, 237, 31,  26,  219, 153, 141, 51,  159, 17,  131,
+    20};
 
-void md2_hash(size_t len, const uint8_t buf[len], uint8_t out[16]) {}
+void printBuf(size_t len, uint8_t buf[len]) {
+  for (int i = 0; i < len; i++) {
+    printf("'%02x',", buf[i]);
+  }
+  printf("\n");
+}
+
+void md2_checksum(size_t len, uint8_t* buf) {
+  uint8_t l = 0;
+
+  for (int i = 0; i < len / 16; i++) {
+    for (int j = 0; j < 16; j++) {
+      u_int8_t c = buf[i * 16 + j];
+      // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
+      l = buf[len + j] ^= PI_SUBST[c ^ l];
+    }
+  }
+}
+
+void md2_hash(size_t len, const uint8_t buf[len], uint8_t out[16]) {
+  // === step 1 ===
+  int paddingNeeded = 16 - (len % 16);
+  uint8_t originalPadding = paddingNeeded;
+  len += paddingNeeded;
+
+  // printf("len: %d\n", len);
+
+  // +16 for the checksum
+  uint8_t* newBuf = calloc(len + 16, sizeof(uint8_t));
+  memcpy(newBuf, buf, len - paddingNeeded);
+
+  // printBuf(len + 16, newBuf);
+
+  while (paddingNeeded > 0) {
+    newBuf[len - paddingNeeded] = originalPadding;
+    paddingNeeded--;
+  }
+  // printf("buf with padding: ");
+  // printBuf(len + 16, newBuf);
+
+  // === step 2 ===
+  md2_checksum(len, newBuf);
+
+  // printf("buf with cecksum: ");
+  // printBuf(len + 16, newBuf);
+
+  // === step 3 ===
+  uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
+
+  // === step 4 ===
+  // <= because we need to hash the last block too
+  for (int i = 0; i <= (len + 16) / 16 - 1; i++) {
+    for (int j = 0; j < 16; j++) {
+      messageDigestBuf[16 + j] = newBuf[i * 16 + j];
+      messageDigestBuf[32 + j] =
+          (messageDigestBuf[16 + j] ^ messageDigestBuf[j]);
+    }
+
+    u_int8_t t = 0;
+
+    for (int j = 0; j < 18; j++) {
+      for (int k = 0; k < 48; k++) {
+        t = messageDigestBuf[k] = messageDigestBuf[k] ^ PI_SUBST[t];
+      }
+      t = (t + j) % 256;
+    }
+  }
+  // printf("messageDigestBuf: \n");
+  // printBuf(16, messageDigestBuf);
+
+  memcpy(out, messageDigestBuf, 16);
+
+  free(messageDigestBuf);
+  free(newBuf);
+}
+
+void encodeHash(uint8_t hash[16], char* stringHash) {
+  for (int i = 0; i < 16; i++) {
+    sprintf(stringHash + (2 * i), "%02x", hash[i]);
+  }
+}