docs: update comment of V3

Implementierung/Makefile

@@ -4,7 +4,7 @@ SRC = src/main.c src/helper.c src/io.c src/md2.c src/md2_impls/md2_common.c src/
 OBJ = ${subst src,build,${SRC:.c=.o}}
 CC = gcc
 CFLAGS = -Ilib -ggdb -std=c11 -g -Wall -Wextra -no-pie -O3 
-LDFLAGS = 
+LDFLAGS = -pthread
 
 all: md2
 

Implementierung/lib/md2_impls/md2_3.h

@@ -1,6 +1,7 @@
 #ifndef MD2_3_H
 #define MD2_3_H
 
+#include <pthread.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -11,10 +12,10 @@
 #include <unistd.h>
 
 /**
- * @brief This implementation loads the file in bits and not at once
+ * @brief Diese Implementierung benutzt Threads zum Berechnen des Hashs
  *
- * @param _ unused
+ * @param len
- * @param filename name of the file to load
+ * @param buf
  * @param out
  */
 void md2_hash_3(size_t len, const uint8_t buf[len], uint8_t out[16]);

Implementierung/src/md2_impls/md2_3.c

@@ -2,7 +2,13 @@
 
 #include "../../lib/md2_impls/md2_common.h"
 
-void process_hash(size_t len, uint8_t buf[len], uint8_t messageDigestBuf[48]) {
+struct thread_args {
+  size_t len;
+  const uint8_t* buf;
+};
+
+void process_nothread_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];
@@ -21,36 +27,57 @@ void process_hash(size_t len, uint8_t buf[len], uint8_t messageDigestBuf[48]) {
   }
 }
 
-void process_checksum(size_t len, uint8_t buf[len], uint8_t checksum[16]) {
+void* process_hash(void* threadArgs) {
+  struct thread_args* args = (struct thread_args*)threadArgs;
+
+  uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
+  if (messageDigestBuf == NULL) {
+    return;
+  }
+
+  for (size_t i = 0; i < (args->len + 16) / 16 - 1; i++) {
+    for (int j = 0; j < 16; j++) {
+      messageDigestBuf[16 + j] = args->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;
+    }
+  }
+  pthread_exit(messageDigestBuf);
+}
+
+void* process_checksum(void* threasdArgs) {
+  struct thread_args* args = (struct thread_args*)threasdArgs;
+
+  uint8_t* checksum = calloc(16, sizeof(uint8_t));
+  if (checksum == NULL) {
+    return;
+  }
+
   uint8_t l = 0;
 
-  for (size_t i = 0; i < len / 16; i++) {
+  for (size_t i = 0; i < args->len / 16; i++) {
     for (int j = 0; j < 16; j++) {
-      u_int8_t c = buf[i * 16 + j];
+      u_int8_t c = args->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];
     }
   }
+  pthread_exit(checksum);
 }
 
-// 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;
@@ -67,64 +94,35 @@ void md2_hash_3(size_t len, const uint8_t buf[len], uint8_t out[16]) {
     paddingNeeded--;
   }
 
-  // === step 3 ===
+  pthread_t thread_1, thread_2;
-  uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
+
-  if (messageDigestBuf == NULL) {
+  struct thread_args thread_args = {len, newBuf};
-    return;
+
+  if (pthread_create(&thread_1, NULL, process_hash, (void*)&thread_args) != 0) {
+    printf("Error creating thread 1\n");
+    exit(EXIT_FAILURE);
+  }
+  if (pthread_create(&thread_2, NULL, process_checksum, (void*)&thread_args) !=
+      0) {
+    printf("Error creating thread 2\n");
+    exit(EXIT_FAILURE);
   }
 
-  // === step 4 ===
+  u_int8_t* messageDigestBuf;
-  uint8_t* checksum = calloc(16, sizeof(uint8_t));
+  u_int8_t* checksum;
-  if (checksum == NULL) {
+
-    return;
+  if (pthread_join(thread_1, (void**)&messageDigestBuf) != 0) {
+    printf("Error joining thread 1\n");
+    exit(EXIT_FAILURE);
+  }
+  if (pthread_join(thread_2, (void**)&checksum) != 0) {
+    printf("Error joining thread 2\n");
+    exit(EXIT_FAILURE);
   }
 
-  int hashPipe[2];
+  process_nothread_hash(16, checksum, messageDigestBuf);
-  int checksumPipe[2];
+  memcpy(out, messageDigestBuf, 16);
 
-  if (pipe(hashPipe) == -1 || pipe(checksumPipe) == -1) {
+  free(messageDigestBuf);
-    return;
+  free(checksum);
-  }
-
-  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);
 }