Merge pull request 'feat/impl-threading' (#6) from feat/impl-threading into master

Reviewed-on: https://gitlab-gepasp.in.tum.de/gra22s/team199/pulls/6
Reviewed-by: Dorian Zedler <dorian.zedler@tum.de>

Implementierung/Makefile

@@ -1,10 +1,10 @@
 
 
-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 
-LDFLAGS = 
+LDFLAGS = -pthread
 
 all: md2
 

Implementierung/lib/md2_impls/md2_2.h

@@ -18,6 +18,5 @@
  * @param out
  */
 void md2_hash_2(size_t len, const uint8_t buf[len], uint8_t out[16]);
-void md2_checksum_2(size_t len, uint8_t* buf);
 
 #endif  // MD2_2_H

Implementierung/lib/md2_impls/md2_3.h

@@ -0,0 +1,22 @@
+#ifndef MD2_3_H
+#define MD2_3_H
+
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+/**
+ * @brief Diese Implementierung benutzt Threads zum Berechnen des Hashs
+ *
+ * @param len
+ * @param buf
+ * @param out
+ */
+void md2_hash_3(size_t len, const uint8_t buf[len], uint8_t out[16]);
+
+#endif  // MD2_3_H

Implementierung/lib/md2_impls/md2_common.h

@@ -1,6 +1,7 @@
 #ifndef MD2_COMMON_H
 #define MD2_COMMON_H
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>

Implementierung/src/main.c

@@ -4,7 +4,6 @@
 #include "../lib/io.h"
 #include "../lib/md2.h"
 
-// Returns true when val is approx. equal to exp.
 static bool runTest(struct configuration* c, const char* message,
                     const char* expectedHash) {
   uint8_t out[16];

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;
@@ -25,7 +26,12 @@ bool md2_choose_implementation(int i) {
 
     case 2:
       md2_hash = md2_hash_2;
-      md2_checksum = md2_checksum_2;
+      md2_checksum = NULL;
+      return true;
+
+    case 3:
+      md2_hash = md2_hash_3;
+      md2_checksum = NULL;
       return true;
 
     default:

Implementierung/src/md2_impls/md2_2.c

@@ -38,9 +38,6 @@ void apply_padding(size_t len, uint8_t buf[16]) {
   }
 }
 
-// unused!
-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;
   struct stat file_stat;
@@ -62,8 +59,8 @@ void md2_hash_2(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   while (bytes_left_to_read != 0) {
     bytes_left_to_process = bytes_left_to_read >= 16 ? 16 : bytes_left_to_read;
 
-    fread(data, 1, bytes_left_to_process, file);
+    size_t size = fread(data, 1, bytes_left_to_process, file);
-    if (ferror(file) || feof(file)) {
+    if (size == 0 || ferror(file) || feof(file)) {
       if (errno == 0) errno = EIO;
       return;
     }

Implementierung/src/md2_impls/md2_3.c

@@ -0,0 +1,114 @@
+#include "../../lib/md2_impls/md2_3.h"
+
+#include "../../lib/md2_impls/md2_common.h"
+
+struct thread_args {
+  size_t len;
+  const uint8_t* buf;
+};
+
+void process_nothread_hash(size_t len, const 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_hash(void* threadArgs) {
+  struct thread_args* args = (struct thread_args*)threadArgs;
+
+  uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
+  if (messageDigestBuf == NULL) {
+    return NULL;
+  }
+
+  process_nothread_hash(args->len, args->buf, messageDigestBuf);
+  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 NULL;
+  }
+
+  uint8_t l = 0;
+
+  for (size_t i = 0; i < args->len / 16; i++) {
+    for (int j = 0; j < 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);
+}
+
+void md2_hash_3(size_t len, const uint8_t buf[len], uint8_t out[16]) {
+  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--;
+  }
+
+  pthread_t thread_1, thread_2;
+
+  struct thread_args thread_args = {len, newBuf};
+
+  if (pthread_create(&thread_1, NULL, process_hash, (void*)&thread_args) != 0) {
+    printf("Error creating thread 1\n");
+    if (errno == 0) errno = EAGAIN;
+    return;
+  }
+  if (pthread_create(&thread_2, NULL, process_checksum, (void*)&thread_args) !=
+      0) {
+    printf("Error creating thread 2\n");
+    if (errno == 0) errno = EAGAIN;
+    return;
+  }
+
+  u_int8_t* messageDigestBuf;
+  u_int8_t* checksum;
+
+  if (pthread_join(thread_1, (void**)&messageDigestBuf) != 0) {
+    printf("Error joining thread 1\n");
+    if (errno == 0) errno = EINVAL;
+    return;
+  }
+  if (pthread_join(thread_2, (void**)&checksum) != 0) {
+    printf("Error joining thread 2\n");
+    if (errno == 0) errno = EINVAL;
+    return;
+  }
+
+  process_nothread_hash(16, checksum, messageDigestBuf);
+  memcpy(out, messageDigestBuf, 16);
+
+  free(messageDigestBuf);
+  free(checksum);
+}