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我想创建下使用OpenSSL的这么一个加密聊天服务器上创建聊天服务器,已经采取了代码:http://simplestcodings.blogspot.in/2010/08/secure-server-client-using-openssl-in-c.html如何使用OpenSSL的在C
我想这个代码转换为并行聊天服务器,但如何能我那样做?
当我尝试客户端与服务器的连接,它只是显示:
在服务器端:
Connection: 127.0.0.1:34902
No certificates.
Client msg: "Hello???"
在客户端:
Connected with AES256-GCM-SHA384 encryption
Server certificates:
Subject: /C=IN/ST=UK/L=DDN/O=UPES/OU=IT/CN=KAVIN/[email protected]
Issuer: /C=IN/ST=UK/L=DDN/O=UPES/OU=IT/CN=KAVIN/[email protected]
Received: "<html><body><pre>Hello???</pre></body></html>
"
我希望做一个客户端和服务器之间的加密聊天
server.c
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <malloc.h>
#include <string.h>
#include <sys/socket.h>
#include <resolv.h>
#include <netdb.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#define FAIL -1
int OpenConnection(const char *hostname, int port)
{ int sd;
struct hostent *host;
struct sockaddr_in addr;
if ((host = gethostbyname(hostname)) == NULL)
{
perror(hostname);
abort();
}
sd = socket(PF_INET, SOCK_STREAM, 0);
bzero(&addr, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = *(long*)(host->h_addr);
if (connect(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0)
{
close(sd);
perror(hostname);
abort();
}
return sd;
}
SSL_CTX* InitCTX(void)
{ SSL_METHOD *method;
SSL_CTX *ctx;
OpenSSL_add_all_algorithms(); /* Load cryptos, et.al. */
SSL_load_error_strings(); /* Bring in and register error messages */
method = TLSv1_2_client_method(); /* Create new client-method instance */
ctx = SSL_CTX_new(method); /* Create new context */
if (ctx == NULL)
{
ERR_print_errors_fp(stderr);
abort();
}
return ctx;
}
void ShowCerts(SSL* ssl)
{ X509 *cert;
char *line;
cert = SSL_get_peer_certificate(ssl); /* get the server's certificate */
if (cert != NULL)
{
printf("Server certificates:\n");
line = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
printf("Subject: %s\n", line);
free(line); /* free the malloc'ed string */
line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
printf("Issuer: %s\n", line);
free(line); /* free the malloc'ed string */
X509_free(cert); /* free the malloc'ed certificate copy */
}
else
printf("Info: No client certificates configured.\n");
}
int main(int count, char *strings[])
{ SSL_CTX *ctx;
int server;
SSL *ssl;
char buf[1024];
int bytes;
char *hostname, *portnum;
if (count != 3)
{
printf("usage: %s <hostname> <portnum>\n", strings[0]);
exit(0);
}
SSL_library_init();
hostname=strings[1];
portnum=strings[2];
ctx = InitCTX();
server = OpenConnection(hostname, atoi(portnum));
ssl = SSL_new(ctx); /* create new SSL connection state */
SSL_set_fd(ssl, server); /* attach the socket descriptor */
if (SSL_connect(ssl) == FAIL) /* perform the connection */
ERR_print_errors_fp(stderr);
else
{ char *msg = "Hello???";
printf("Connected with %s encryption\n", SSL_get_cipher(ssl));
ShowCerts(ssl);
/* get any certs */
while(1){
SSL_write(ssl, msg, strlen(msg)); /* encrypt & send message */
bytes = SSL_read(ssl, buf, sizeof(buf)); /* get reply & decrypt */
buf[bytes] = 0;
printf("Received: \"%s\"\n", buf);
SSL_free(ssl); /* release connection state */
}
close(server); /* close socket */
SSL_CTX_free(ctx); /* release context */
return 0;
}
Client.c
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <malloc.h>
#include <string.h>
#include <sys/socket.h>
#include <resolv.h>
#include <netdb.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#define FAIL -1
int OpenConnection(const char *hostname, int port)
{ int sd;
struct hostent *host;
struct sockaddr_in addr;
if ((host = gethostbyname(hostname)) == NULL)
{
perror(hostname);
abort();
}
sd = socket(PF_INET, SOCK_STREAM, 0);
bzero(&addr, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = *(long*)(host->h_addr);
if (connect(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0)
{
close(sd);
perror(hostname);
abort();
}
return sd;
}
SSL_CTX* InitCTX(void)
{ SSL_METHOD *method;
SSL_CTX *ctx;
OpenSSL_add_all_algorithms(); /* Load cryptos, et.al. */
SSL_load_error_strings(); /* Bring in and register error messages */
method = TLSv1_2_client_method(); /* Create new client-method instance */
ctx = SSL_CTX_new(method); /* Create new context */
if (ctx == NULL)
{
ERR_print_errors_fp(stderr);
abort();
}
return ctx;
}
void ShowCerts(SSL* ssl)
{ X509 *cert;
char *line;
cert = SSL_get_peer_certificate(ssl); /* get the server's certificate */
if (cert != NULL)
{
printf("Server certificates:\n");
line = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
printf("Subject: %s\n", line);
free(line); /* free the malloc'ed string */
line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
printf("Issuer: %s\n", line);
free(line); /* free the malloc'ed string */
X509_free(cert); /* free the malloc'ed certificate copy */
}
else
printf("Info: No client certificates configured.\n");
}
int main(int count, char *strings[])
{ SSL_CTX *ctx;
int server;
SSL *ssl;
char buf[1024];
int bytes;
char *hostname, *portnum;
if (count != 3)
{
printf("usage: %s <hostname> <portnum>\n", strings[0]);
exit(0);
}
SSL_library_init();
hostname=strings[1];
portnum=strings[2];
ctx = InitCTX();
server = OpenConnection(hostname, atoi(portnum));
ssl = SSL_new(ctx); /* create new SSL connection state */
SSL_set_fd(ssl, server); /* attach the socket descriptor */
if (SSL_connect(ssl) == FAIL) /* perform the connection */
ERR_print_errors_fp(stderr);
else
{ char *msg = "Hello???";
printf("Connected with %s encryption\n", SSL_get_cipher(ssl));
ShowCerts(ssl);
/* get any certs */
while(1){
SSL_write(ssl, msg, strlen(msg)); /* encrypt & send message */
bytes = SSL_read(ssl, buf, sizeof(buf)); /* get reply & decrypt */
buf[bytes] = 0;
printf("Received: \"%s\"\n", buf);
SSL_free(ssl); /* release connection state */
}
close(server); /* close socket */
SSL_CTX_free(ctx); /* release context */
return 0;
}
请评论中的代码为改变正如您已经使用了SSL功能的代码转换为加密的聊天服务器
其实我想发送和接收静音和服务器之间的消息,以便它可以像加密聊天应用程序一样工作。因为在上面的代码中我无法发送和接收消息它只是说(“你好”) – kavin
逻辑是加密“hello”消息,然后发送加密的消息。现在在使用公共密钥的另一侧,解密消息。如果任何欺诈/中间人攻击进入,那么加密的消息将被传送。没有公共密钥就无法解密信息。这些是加密和解密的功能。你可以在你的代码中使用它。 –
这引出了一个问题:如何在两个设备之间共享密钥,以及如何对设备/人员进行身份验证。 – zaph