Feat: Implement V2

Implementierung/lib/io.h

@@ -10,6 +10,17 @@
 #include <stdlib.h>
 #include <sys/stat.h>
 
+/**
+ * @brief Open a file and load its stats
+ *
+ * @param path the filepath
+ * @param file where the pointer of the file handle should be stored
+ * @param file_stat pointer to a stat struct
+ * @return true it worked
+ * @return false there was an error
+ */
+bool open_file(const char* path, FILE** file, struct stat* file_stat);
+
 /**
  * @brief reads a file at a path
  *

Implementierung/lib/md2_impls/md2_2.h

@@ -8,6 +8,8 @@
 #include <string.h>
 #include <sys/types.h>
 
+#include "../io.h"
+
 /**
  * @brief This implementation loads the file in bits and not at once
  *

Implementierung/src/io.c

@@ -1,26 +1,35 @@
 #include "../lib/io.h"
 
+bool open_file(const char* path, FILE** file, struct stat* file_stat) {
+  (*file) = fopen(path, "r");
+  if ((*file) == NULL) {
+    printf("Fopen error: %d\n", errno);
+    fclose((*file));
+    return false;
+  }
+
+  int status = fstat(fileno((*file)), file_stat);
+  if (status == -1) {
+    printf("Fstat error: %d\n", errno);
+    fclose((*file));
+    return false;
+  };
+
+  if ((file_stat->st_mode & S_IFMT) != S_IFREG) {
+    printf("File is not a regular file!\n");
+    fclose((*file));
+    return false;
+  }
+
+  return true;
+}
+
 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");
-  if (f == NULL) {
-    printf("Fopen error: %d\n", errno);
-    fclose(f);
-    return NULL;
-  }
-
+  FILE* f;
   struct stat statOfFile;
-  int status = fstat(fileno(f), &statOfFile);
-  if (status == -1) {
-    printf("Fstat error: %d\n", errno);
-    fclose(f);
-    return NULL;
-  };
-
-  if ((statOfFile.st_mode & S_IFMT) != S_IFREG) {
-    printf("File is not a regular file!\n");
-    fclose(f);
+  if (!open_file(path, &f, &statOfFile)) {
     return NULL;
   }
 

Implementierung/src/main.c

@@ -62,6 +62,38 @@ unsigned runTests(struct configuration* c) {
   return failed;
 }
 
+bool calculate_hash(struct configuration c, char* hash) {
+  size_t len;
+  uint8_t* data;
+
+  if (c.implementationToUse != 2) {
+    data = read_file(c.filename, &len);
+  } else {
+    data = (uint8_t*)c.filename;
+    len = 0;
+  }
+
+  if (data == NULL) {
+    printf("Error reading file %s!", c.filename);
+    return false;
+  }
+
+  uint8_t out[16];
+  if (c.doBenchmark) {
+    double duration =
+        run_benchmark(c.benchmarkingCycles, md2_hash, len, data, out);
+    printf("Running %d cycles took %f seconds\n", c.benchmarkingCycles,
+           duration);
+  } else {
+    md2_hash(len, data, out);
+  }
+
+  md2_encode_hash(out, hash);
+
+  if (c.implementationToUse != 2) free(data);
+  return true;
+}
+
 int main(int argc, char** argv) {
   struct configuration c;
   enum argumentParseResult result = parseArguments(argc, argv, &c);
@@ -87,33 +119,21 @@ int main(int argc, char** argv) {
       "benchmark cycles: %d\n",
       c.implementationToUse, c.doBenchmark, c.benchmarkingCycles);
 
+  if (c.runTests && c.implementationToUse == 2) {
+    fprintf(stderr, "Cannot run tests on implementation 2!");
+    return EXIT_FAILURE;
+  }
+
   if (c.runTests) {
     printf("Running tests...\n\n");
     return runTests(&c);
   }
 
   printf("Hashing file %s...\n\n", c.filename);
-  size_t len;
-  uint8_t* data = read_file(c.filename, &len);
-  if (data == NULL) {
-    printf("Error reading file %s!", c.filename);
-    return EXIT_FAILURE;
-  }
 
-  uint8_t out[16];
   char hash[32];
-  if (c.doBenchmark) {
-    double duration =
-        run_benchmark(c.benchmarkingCycles, md2_hash, len, data, out);
-    printf("Running %d cycles took %f seconds\n", c.benchmarkingCycles,
-           duration);
-  } else {
-    md2_hash(len, data, out);
-  }
-  md2_encode_hash(out, hash);
+  calculate_hash(c, hash);
   printf("Hash: %s\n", hash);
 
-  free(data);
-
   return 0;
 }

Implementierung/src/md2_impls/md2_2.c

@@ -27,30 +27,26 @@ void process_block_checksum(uint8_t block[16], uint8_t checksum[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]) {
-  // === step 1 ===
+void apply_padding(size_t len, uint8_t buf[16]) {
   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, sizeof(uint8_t));
-  // TODO: null check
-  memcpy(newBuf, buf, len - paddingNeeded);
-
-  // printBuf(len + 16, newBuf);
-
   while (paddingNeeded > 0) {
-    newBuf[len - paddingNeeded] = originalPadding;
+    buf[len - paddingNeeded] = originalPadding;
     paddingNeeded--;
   }
-  // printf("buf with padding: ");
-  // printBuf(len + 16, newBuf);
+  printf("buf with padding: ");
+  md2_print_buf(len, buf);
+}
+
+// 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;
+  open_file((char*)buf, &file, &file_stat);
 
   // === step 3 ===
   uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
@@ -59,16 +55,33 @@ void md2_hash_2(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   uint8_t l = 0;
   uint8_t* checksum = calloc(16, sizeof(uint8_t));
 
-  for (size_t i = 0; i < len / 16; i++) {
-    process_block_checksum(newBuf + (i * 16), checksum, &l);
-    process_block_hash(newBuf + (i * 16), messageDigestBuf);
-  }
+  uint8_t* data = malloc(16);
+  size_t bytes_left_to_read = file_stat.st_size;
+  size_t bytes_left_to_process = 0;
+
+  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);
+    if (ferror(file) || feof(file)) {
+      fprintf(stderr, "Error reading the file!");
+      return;
+    }
+
+    process_block_checksum(data, checksum, &l);
+    process_block_hash(data, messageDigestBuf);
+
+    bytes_left_to_read -= bytes_left_to_process;
+  };
+
+  apply_padding(bytes_left_to_process % 16, data);
+  process_block_checksum(data, checksum, &l);
+  process_block_hash(data, messageDigestBuf);
 
   process_block_hash(checksum, messageDigestBuf);
-
   memcpy(out, messageDigestBuf, 16);
 
-  free(newBuf);
+  free(data);
   free(messageDigestBuf);
   free(checksum);
 }