Multi thread

README.rst

@@ -5,19 +5,20 @@ C implementation of Data Encryption Standard algorithm.
 
 Overview
 ========
-The Data Encryption Standard (DES) is a block cipher (a form of shared secret encryption) that was selected by the National 
-Bureau of Standards as an official Federal Information Processing Standard (FIPS) for the United States in 1976 and which 
+The Data Encryption Standard (DES) is a block cipher (a form of shared secret encryption) that was selected by the National
+Bureau of Standards as an official Federal Information Processing Standard (FIPS) for the United States in 1976 and which
 has subsequently enjoyed widespread use internationally. It is based on a symmetric-key algorithm that uses a 56-bit key.
 
-This implementation of DES is not optimized in any way. The code has been written to provide readability and easy 
+This implementation of DES is not optimized in any way. The code has been written to provide readability and easy
 understanding of the algorithm. Padding scheme used in this implementation is `[PKCS5] <ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-5v2/pkcs5v2-0.pdf>`_
 
 Compilation & Installation
 ==========================
 This implementation has only been tested on Unix platform. But you may be able to compile/ run it on Windows.
 
-1. Make sure des.c, des.h and run_des.c are in the same directory 
-2. Compile using: gcc -O3 des.c run_des.c -o run_des.o   
+1. Make sure des.c, des.h and run_des.c are in the same directory
+2. Install pthread library
+3. Compile using: g++ -pthread des.cpp run_des.cpp -o run_des.o
 
 Usage
 =====
@@ -28,10 +29,10 @@ Say we want to encrypt/ decrypt a file named /home/user/sample.txt
     run_des.o -g /tmp/keyfile.key
 2. Encrypt sample.txt using::
 
-    run_des.o -e /tmp/keyfile.key /home/user/sample.txt /home/user/sample.enc
+    run_des.o -e /tmp/keyfile.key /home/user/sample.txt /home/user/sample.enc number_of_threads
 3. Decrypt sample.txt using::
 
-    run_des.o -d /tmp/keyfile.key /home/user/sample.enc /home/user/sample_decrypted.txt
+    run_des.o -d /tmp/keyfile.key /home/user/sample.enc /home/user/sample_decrypted.txt number_of_threads
 
 Don't lose the key file! you won't be able to decrypt an encrypted if you lose the keyfile.
 
@@ -50,15 +51,15 @@ It is possible to use this implementation to facilitate TripleDES encryption pro
 
 2. Encrypt using::
 
-    run_des.o -e /tmp/keyfile1.key /home/user/sample.txt /home/user/sample.enc1
-    run_des.o -e /tmp/keyfile2.key /home/user/sample.enc1 /home/user/sample.enc2
-    run_des.o -e /tmp/keyfile3.key /home/user/sample.enc2 /home/user/sample.enc3
+    run_des.o -e /tmp/keyfile1.key /home/user/sample.txt /home/user/sample.enc1 1
+    run_des.o -e /tmp/keyfile2.key /home/user/sample.enc1 /home/user/sample.enc2 2
+    run_des.o -e /tmp/keyfile3.key /home/user/sample.enc2 /home/user/sample.enc3 4
 
 3. Decrypt using::
 
-    run_des.o -d /tmp/keyfile3.key /home/user/sample.enc3 /home/user/sample.dec3
-    run_des.o -d /tmp/keyfile2.key /home/user/sample.dec3 /home/user/sample.dec2
-    run_des.o -d /tmp/keyfile1.key /home/user/sample.dec2 /home/user/sample_decrypted.txt
+    run_des.o -d /tmp/keyfile3.key /home/user/sample.enc3 /home/user/sample.dec3 1
+    run_des.o -d /tmp/keyfile2.key /home/user/sample.dec3 /home/user/sample.dec2 2
+    run_des.o -d /tmp/keyfile1.key /home/user/sample.dec2 /home/user/sample_decrypted.txt 4
 
 The primary repository for DES is located at: `http://github.com/tarequeh/DES/ <http://github.com/tarequeh/DES/>`_ The blog post
 discussing the implementation can be found at: `CodeXN <http://www.codexn.com>`_

run_des.c → run_des.cpp

@@ -2,6 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <vector>
+#include <pthread.h>
 
 /*
  * des.h provides the following functions and constants:
@@ -11,6 +13,7 @@
  */
 #include "des.h"
 
+using namespace std;
 // Declare file handlers
 static FILE *key_file, *input_file, *output_file;
 
@@ -22,11 +25,41 @@ static FILE *key_file, *input_file, *output_file;
 // DES key is 8 bytes long
 #define DES_KEY_SIZE 8
 
+#define ucharmalloc (unsigned char*) malloc(8*sizeof(char))
+
+#define MAX_POSIBLE_THREADS 16
+
+short int process_mode;
+vector<unsigned char*> output[MAX_POSIBLE_THREADS];
+vector<unsigned char*> input[MAX_POSIBLE_THREADS];
+unsigned long file_size;
+key_set* key_sets = (key_set*)malloc(17*sizeof(key_set));
+int nThread = 1;
+
+void *converter(void* index) {
+	clock_t start = clock();
+	long i = (long) index;
+	unsigned short int padding;
+	vector<unsigned char*>::iterator it;
+	for (it = input[i].begin(); it != input[i].end(); it++) {
+		if (it + 1 == input[i].end() && i == nThread - 1) {
+			padding = 8 - file_size%8;
+			if (padding < 8) { // Fill empty data block bytes with padding
+				memset((*it + 8 - padding), (unsigned char)padding, padding);
+			}
+		}
+		output[i].push_back(ucharmalloc);
+		process_message(*it, output[i].back(), key_sets, process_mode);
+	}
+	clock_t finish = clock();
+	double time_taken = (double)(finish - start)/(double)CLOCKS_PER_SEC/nThread;
+	printf("thread[%ld] : %lf seconds\n", i, time_taken);
+	pthread_exit(NULL);
+}
+
 int main(int argc, char* argv[]) {
 	clock_t start, finish;
 	double time_taken;
-	unsigned long file_size;
-	unsigned short int padding;
 
 	if (argc < 2) {
 		printf("You must provide at least 1 parameter, where you specify the action.");
@@ -62,10 +95,11 @@ int main(int argc, char* argv[]) {
 		free(des_key);
 		fclose(key_file);
 	} else if ((strcmp(argv[1], ACTION_ENCRYPT) == 0) || (strcmp(argv[1], ACTION_DECRYPT) == 0)) { // Encrypt or decrypt
-		if (argc != 5) {
-			printf("Invalid # of parameters (%d) specified. Usage: run_des [-e|-d] keyfile.key input.file output.file", argc);
+		if (argc != 6) {
+			printf("Invalid # of parameters (%d) specified. Usage: run_des [-e|-d] keyfile.key input.file output.file [number_of_threads]", argc);
 			return 1;
 		}
+		nThread = atoi(argv[5]);
 
 		// Read key file
 		key_file = fopen(argv[2], "rb");
@@ -99,11 +133,10 @@ int main(int argc, char* argv[]) {
 		}
 
 		// Generate DES key set
-		short int bytes_written, process_mode;
+		short int bytes_written;
 		unsigned long block_count = 0, number_of_blocks;
 		unsigned char* data_block = (unsigned char*) malloc(8*sizeof(char));
 		unsigned char* processed_block = (unsigned char*) malloc(8*sizeof(char));
-		key_set* key_sets = (key_set*)malloc(17*sizeof(key_set));
 
 		start = clock();
 		generate_sub_keys(des_key, key_sets);
@@ -129,55 +162,68 @@ int main(int argc, char* argv[]) {
 		start = clock();
 
 		// Start reading input file, process and write to output file
-		while(fread(data_block, 1, 8, input_file)) {
-			block_count++;
-			if (block_count == number_of_blocks) {
-				if (process_mode == ENCRYPTION_MODE) {
-					padding = 8 - file_size%8;
-					if (padding < 8) { // Fill empty data block bytes with padding
-						memset((data_block + 8 - padding), (unsigned char)padding, padding);
-					}
-
-					process_message(data_block, processed_block, key_sets, process_mode);
-					bytes_written = fwrite(processed_block, 1, 8, output_file);
-
-					if (padding == 8) { // Write an extra block for padding
-						memset(data_block, (unsigned char)padding, 8);
-						process_message(data_block, processed_block, key_sets, process_mode);
-						bytes_written = fwrite(processed_block, 1, 8, output_file);
-					}
-				} else {
-					process_message(data_block, processed_block, key_sets, process_mode);
-					padding = processed_block[7];
-
-					if (padding < 8) {
-						bytes_written = fwrite(processed_block, 1, 8 - padding, output_file);
-					}
-				}
-			} else {
-				process_message(data_block, processed_block, key_sets, process_mode);
-				bytes_written = fwrite(processed_block, 1, 8, output_file);
+		pthread_t thread[nThread];
+		unsigned long chunkSize = number_of_blocks / nThread;
+		for (int i = 0; i < nThread; i++) {
+			unsigned long start = chunkSize * i;
+			unsigned long end = start + chunkSize;
+			if (i == nThread - 1) {
+				end = number_of_blocks;
+			}
+			for (block_count = start; block_count < end; block_count++) {
+				input[i].push_back(ucharmalloc);
+				fread(input[i].back(), 1, 8, input_file);
 			}
-			memset(data_block, 0, 8);
+		}
+
+		clock_t start_convert = clock();
+		// pthread_attr_t attr;
+		// void *status;
+		// pthread_attr_init(&attr);
+		// pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+		for(int i = 0; i < nThread; i++) {
+			pthread_create(&thread[i], NULL, converter, (void*) i);
+		}
+		// pthread_attr_destroy(&attr);
+
+		for(int i = 0; i < nThread; i++) {
+			pthread_join(thread[i], NULL);
+		}
+		clock_t end_convert = clock();
+		double time_convert_taken = (double)(end_convert - start_convert)/(double)CLOCKS_PER_SEC/nThread;
+		printf("[%lf seconds]\n", time_convert_taken);
+
+		vector<unsigned char*>::iterator it;
+		for (int i = 0; i < nThread; i++) {
+			for (it = output[i].begin(); it != output[i].end(); ++it) {
+				bytes_written = fwrite(*it, 1, 8, output_file);
+				delete *it;
+			}
+		}
+		for (int i = 0; i < nThread; i++) {
+			for (it = input[i].begin(); it != input[i].end(); ++it) {
+				delete *it;
+			}
+			input[i].clear();
+			output[i].clear();
 		}
 
 		finish = clock();
+		time_taken = (double)(finish - start)/(double)CLOCKS_PER_SEC/nThread;
+		printf("Finished processing %s. Time taken: %lf seconds.\n", argv[3], time_taken);
 
 		// Free up memory
 		free(des_key);
 		free(data_block);
 		free(processed_block);
 		fclose(input_file);
 		fclose(output_file);
-
+		pthread_exit(NULL);
 		// Provide feedback
-		time_taken = (double)(finish - start)/(double)CLOCKS_PER_SEC;
-		printf("Finished processing %s. Time taken: %lf seconds.\n", argv[3], time_taken);
 		return 0;
 	} else {
 		printf("Invalid action: %s. First parameter must be [ -g | -e | -d ].", argv[1]);
 		return 1;
 	}
-
 	return 0;
 }