HTTPS_Socket.c

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <openssl/ssl.h>
#include <openssl/err.h>

#define IP_ADDR "127.0.0.1"
#define PORT_NUM 8080
#define CERT_FILE "cert.pem"
#define KEY_FILE "key.pem"
#define MAX 1024
SSL_CTX *ctx;
void * serverThread(void *arg);
void setupServerCtx(void);
void bind_and_listen(int serv_sock, struct sockaddr_in* serv_adr, int backlog, int port);
void accept_connection(int serv_sock, struct sockaddr_in clnt_addr);
int serverLoop(SSL * ssl);
void * serverThread(void *arg);
void* handle_client_request(SSL* ssl);
void send_data_ssl(SSL* ssl, char* ct, char* file_name);
char* content_type(char* file);
void send_error(SSL* ssl);
void error_handling(char* message);

int main(int argc,char *argv[]) {
	int serv_sock;
	struct sockaddr_in serv_addr, clnt_addr;
	SSL *ssl;

	setupServerCtx();

	//socket
	serv_sock = socket(PF_INET, SOCK_STREAM, 0);
	bind_and_listen(serv_sock, &serv_addr, 20, PORT_NUM);

	while (1) {
		accept_connection(serv_sock, clnt_addr);
	}
	SSL_CTX_free(ctx);
}
void setupServerCtx(void){
    	//SSL library memset-> 0
	SSL_library_init();
	const SSL_METHOD *method;
	method = TLS_server_method();
	ctx = SSL_CTX_new(method);
	if(SSL_CTX_use_certificate_file(ctx, CERT_FILE, SSL_FILETYPE_PEM) != 1)
		error_handling("cert err");
	if(SSL_CTX_use_PrivateKey_file(ctx, KEY_FILE, SSL_FILETYPE_PEM)	!= 1)
		error_handling("private err");
}
void bind_and_listen(int serv_sock, struct sockaddr_in* serv_adr, int backlog, int port){
	memset(serv_adr, 0, sizeof(struct sockaddr_in));
	serv_adr->sin_family = AF_INET;
	serv_adr->sin_addr.s_addr = htonl(INADDR_ANY);
	serv_adr->sin_port = htons(port);

	if(	(bind(serv_sock, (struct sockaddr*)serv_adr, sizeof(struct sockaddr_in))) == -1)
		error_handling("bind err");
	if(	(listen(serv_sock, backlog)) == -1)
		error_handling("listen err");
}
void accept_connection(int serv_sock, struct sockaddr_in clnt_addr){
	SSL *ssl;
	int clnt_sock;
	pthread_t tid;
	socklen_t clnt_addr_size;
	clnt_addr_size = sizeof(clnt_addr);
	clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, (socklen_t*)&clnt_addr_size);

	ssl = SSL_new(ctx);
	SSL_set_fd(ssl,clnt_sock);
	pthread_create (&tid, NULL, serverThread, ssl);
	pthread_detach(tid);
}
void * serverThread(void *arg){
	SSL *ssl = (SSL *) arg;

	if (SSL_accept(ssl) <= 0){
		error_handling("hand-shake err");
		SSL_free(ssl);
		return 0;
	}
	fprintf(stderr, "SSL Connection opened\n");
	handle_client_request(ssl);
	fprintf(stderr, "SSL Connection closed\n");
}
void* handle_client_request(SSL *ssl) {
	char req_line[MAX];
	char method[MAX];
	char ct[MAX];
	char file_name[MAX];
	char buf[MAX];

	SSL_read(ssl, req_line, MAX);	
    /*HTTP 헤더가 아닌경우 종료*/
	if (strstr(req_line, "HTTP/")== NULL) {
		send_error(ssl);
		SSL_shutdown(ssl);
		SSL_free(ssl);
		return 0;
	}
	strcpy(method, strtok(req_line, " /"));

    /*GET 메소드가 아닌경우 종료*/
	if (strcmp(method, "GET") != 0) {
		send_error(ssl);
		SSL_shutdown(ssl);
		SSL_free(ssl);
		return 0;
	}

    /*파일 전송*/
	strcpy(file_name, strtok(NULL, " /"));
	strcpy(ct, content_type(file_name));
	send_data_ssl(ssl, ct, file_name); //입력받은 데이터에 해당하는 파일을 전송함

}

/*http 헤더를 받고 지정된 파일을 전송한다.*/
void send_data_ssl(SSL* ssl, char* ct, char* file_name) {
	char protocol[] = "HTTP/1.0 200 OK\r\n";
	char server[] = "Server:Linux Web Server\r\n";
	char cnt_len[] = "Content-lenght:2048\r\n";
	char cnt_type[MAX];
	char buf[MAX];
	FILE* send_file;

	sprintf(cnt_type, "Content-type :%s\r\n\r\n", ct);
	send_file = fopen(file_name, "r");
	if (send_file == NULL) {
		send_error(ssl);
		SSL_shutdown(ssl);
		SSL_free(ssl);
		return;
	}

	SSL_write(ssl, protocol, strlen(protocol));
	SSL_write(ssl, server, strlen(server));
	SSL_write(ssl, cnt_len, strlen(cnt_len));
	SSL_write(ssl, cnt_type, strlen(cnt_type));

	while (fgets(buf, MAX, send_file) != NULL) {
		SSL_write(ssl, buf, strlen(buf));
	}

	fclose(send_file);
	SSL_shutdown(ssl);
	SSL_free(ssl);
}

/*헤더를 읽어와서 헤더의 파일요청 방식이 html이면 html 반환하고 아니면 text 반환*/
char* content_type(char* file) {
	char extension[MAX];
	char file_name[MAX];

	strcpy(file_name, file);
	strtok(file_name, ".");
	strcpy(extension, strtok(NULL, "."));

	if (!strcmp(extension, "html") || !strcmp(extension, "htm"))
		return "text/html";
	else
		return "text/plain";
}

void send_error(SSL* ssl) {
	char protocol[] = "HTTP/1.0 400 Bad Request\r\n";
	char server[] = "Server:Linux Web Server\r\n";
	char cnt_len[] = "Content-length:2048\r\n";
	char cnt_type[] = "Content-type:text/html\r\n\r\n";
	char content[] = "<html><head><title>NETWORK</title><head>""<body><font size+=10><br>오류 발생 요청 파일명 및 요청 방식 확인""</font></body></html>";

	SSL_write(ssl, protocol, strlen(protocol));
	SSL_write(ssl, server, strlen(server));
	SSL_write(ssl, cnt_len, strlen(cnt_len));
	SSL_write(ssl, cnt_type, strlen(cnt_type));
	SSL_write(ssl, content, strlen(content));
}

void error_handling(char* message) {
	fputs(message, stderr);
	fputc('\n', stderr);
	return;
}