feat: implement threading

Implementierung/Makefile

@@ -1,6 +1,6 @@
 
 
-SRC = src/main.c src/helper.c src/io.c src/md2.c src/md2_impls/md2_common.c src/md2_impls/md2_0.c src/md2_impls/md2_2.c
+SRC = src/main.c src/helper.c src/io.c src/md2.c src/md2_impls/md2_common.c src/md2_impls/md2_0.c src/md2_impls/md2_2.c src/md2_impls/md2_3.c
 OBJ = ${subst src,build,${SRC:.c=.o}}
 CC = gcc
 CFLAGS = -Ilib -ggdb -std=c11 -g -Wall -Wextra -no-pie -O3

Implementierung/lib/md2_impls/md2_3.h

@@ -0,0 +1,23 @@
+#ifndef MD2_3_H
+#define MD2_3_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/**
+ * @brief This implementation loads the file in bits and not at once
+ *
+ * @param _ unused
+ * @param filename name of the file to load
+ * @param out
+ */
+void md2_hash_3(size_t len, const uint8_t buf[len], uint8_t out[16]);
+void md2_checksum_3(size_t len, uint8_t* buf);
+
+#endif  // MD2_3_H

Implementierung/src/md2.c

@@ -3,6 +3,7 @@
 // include all implementations
 #include "../lib/md2_impls/md2_0.h"
 #include "../lib/md2_impls/md2_2.h"
+#include "../lib/md2_impls/md2_3.h"
 
 md2_hash_func md2_hash;
 md2_checksum_func md2_checksum;
@@ -28,6 +29,11 @@ bool md2_choose_implementation(int i) {
       md2_checksum = md2_checksum_2;
       return true;
 
+    case 3:
+      md2_hash = md2_hash_3;
+      md2_checksum = md2_checksum_3;
+      return true;
+
     default:
       return false;
   }

Implementierung/src/md2_impls/md2_2.c

@@ -39,7 +39,7 @@ void apply_padding(size_t len, uint8_t buf[16]) {
 }
 
 // unused!
-void md2_checksum_2(size_t, uint8_t*) {}
+void md2_checksum_2(size_t _, uint8_t* __) {}
 
 void md2_hash_2(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   FILE* file;

Implementierung/src/md2_impls/md2_3.c

@@ -0,0 +1,130 @@
+#include "../../lib/md2_impls/md2_3.h"
+
+#include "../../lib/md2_impls/md2_common.h"
+
+void process_hash(size_t len, uint8_t buf[len], uint8_t messageDigestBuf[48]) {
+  for (size_t i = 0; i < (len + 16) / 16 - 1; i++) {
+    for (int j = 0; j < 16; j++) {
+      messageDigestBuf[16 + j] = buf[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] ^ MD2_PI_SUBST[t];
+      }
+      t = (t + j) % 256;
+    }
+  }
+}
+
+void process_checksum(size_t len, uint8_t buf[len], uint8_t checksum[16]) {
+  uint8_t l = 0;
+
+  for (size_t 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 = checksum[j] ^= MD2_PI_SUBST[c ^ l];
+    }
+  }
+}
+
+// DUPLICATE CODE FROM md2_2.c
+// int apply_padding(size_t len, uint8_t buf[len]) {
+//   int paddingNeeded = 16 - (len % 16);
+//   uint8_t originalPadding = paddingNeeded;
+//   len += paddingNeeded;
+
+//   while (paddingNeeded > 0) {
+//     buf[len - paddingNeeded] = originalPadding;
+//     paddingNeeded--;
+//   }
+//   return len;
+// }
+
+// unused!
+void md2_checksum_3(size_t _, uint8_t* __) {}
+
+void md2_hash_3(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;
+
+  uint8_t* newBuf = calloc(len + 16, sizeof(uint8_t));
+  if (newBuf == NULL) {
+    return;
+  }
+
+  memcpy(newBuf, buf, len - paddingNeeded);
+
+  while (paddingNeeded > 0) {
+    newBuf[len - paddingNeeded] = originalPadding;
+    paddingNeeded--;
+  }
+
+  // === step 3 ===
+  uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
+  if (messageDigestBuf == NULL) {
+    return;
+  }
+
+  // === step 4 ===
+  uint8_t* checksum = calloc(16, sizeof(uint8_t));
+  if (checksum == NULL) {
+    return;
+  }
+
+  int hashPipe[2];
+  int checksumPipe[2];
+
+  if (pipe(hashPipe) == -1 || pipe(checksumPipe) == -1) {
+    return;
+  }
+
+  pid_t pid_1, pid_2;
+  (pid_1 = fork()) && (pid_2 = fork());
+
+  if (pid_1 == 0) {
+    // Child 1 process
+    close(hashPipe[0]);
+    process_hash(len, newBuf, messageDigestBuf);
+    write(hashPipe[1], messageDigestBuf, 48);
+    exit(0);
+
+  } else if (pid_2 == 0) {
+    // Child 2 process
+    close(checksumPipe[0]);
+    process_checksum(len, newBuf, checksum);
+    write(checksumPipe[1], checksum, 16);
+    exit(0);
+  } else {
+    // int status;
+    // Parent process
+    close(hashPipe[1]);
+    close(checksumPipe[1]);
+
+    waitpid(pid_1, NULL, 0);
+    waitpid(pid_2, NULL, 0);
+
+    read(hashPipe[0], messageDigestBuf, 48);
+    read(checksumPipe[0], checksum, 16);
+
+    process_hash(16, checksum, messageDigestBuf);
+    memcpy(out, messageDigestBuf, 16);
+
+    // free(data);
+    free(messageDigestBuf);
+    free(checksum);
+  }
+
+  // process_block_checksum(data, checksum, &l);
+  // process_block_hash(data, messageDigestBuf);
+
+  // process_block_checksum(data, checksum, &l);
+  // process_block_hash(data, messageDigestBuf);
+}