我在c ++项目中使用openssl。通过我的代码握手完成没有Serverkey Exchange，我需要这样做。如何在握手中将serverkey交换添加到我的代码中？
服务器代码：
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <memory.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <openssl/rsa.h>
#include <openssl/crypto.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
/* define HOME to be dir for key and cert files... */
#define HOME "./"
/* Make these what you want for cert & key files */
#define CERTF "/home/a.seifpour/Desktop/SSL Tutorial/cert.pem"
#define KEYF "/home/a.seifpour/Desktop/SSL Tutorial/key.pem"
#define CHK_NULL(x) if ((x)==NULL) exit (1)
#define CHK_ERR(err,s) if ((err)==-1) { perror(s); exit(1); }
#define CHK_SSL(err) if ((err)==-1) { ERR_print_errors_fp(stderr); exit(2); }
int main() {
int err;
int listen_sd;
int sd;
struct sockaddr_in sa_serv;
struct sockaddr_in sa_cli;
unsigned int client_len;
SSL_CTX* ctx;
SSL* ssl;
X509* client_cert;
char* str;
char buf [4096];
const SSL_METHOD *meth;
/* SSL preliminaries. We keep the certificate and key with the context. */
SSL_load_error_strings();
OpenSSL_add_ssl_algorithms();
meth = TLSv1_2_server_method();
ctx = SSL_CTX_new(meth);
if (!ctx) {
ERR_print_errors_fp(stderr);
exit(2);
}
if (SSL_CTX_load_verify_locations(ctx, CERTF, KEYF) != 1){
ERR_print_errors_fp(stderr);
}
if (SSL_CTX_set_default_verify_paths(ctx) != 1){
ERR_print_errors_fp(stderr);
}
if (SSL_CTX_use_certificate_file(ctx, CERTF, SSL_FILETYPE_PEM) <= 0) {
ERR_print_errors_fp(stderr);
exit(3);
}
if (SSL_CTX_use_PrivateKey_file(ctx, KEYF, SSL_FILETYPE_PEM) <= 0) {
ERR_print_errors_fp(stderr);
exit(4);
}
if (!SSL_CTX_check_private_key(ctx)) {
fprintf(stderr, "Private key does not match the certificate public key\n");
exit(5);
}
// SSL_CTX_set_verify(ctx,SSL_VERIFY_CLIENT_ONCE, 0);
/* ----------------------------------------------- */
/* Prepare TCP socket for receiving connections */
listen_sd = socket(AF_INET, SOCK_STREAM, 0);
CHK_ERR(listen_sd, "socket");
memset(&sa_serv, 0, sizeof (sa_serv));
sa_serv.sin_family = AF_INET;
sa_serv.sin_addr.s_addr = INADDR_ANY;
sa_serv.sin_port = htons(9999); /* Server Port number */
err = bind(listen_sd, (struct sockaddr*) &sa_serv,
sizeof (sa_serv));
CHK_ERR(err, "bind");
/* Receive a TCP connection. */
err = listen(listen_sd, 5);
CHK_ERR(err, "listen");
client_len = sizeof (sa_cli);
sd = accept(listen_sd, (struct sockaddr*) &sa_cli, &client_len);
CHK_ERR(sd, "accept");
close(listen_sd);
printf("Connection from %lx, port %x\n",
sa_cli.sin_addr.s_addr, sa_cli.sin_port);
/* ----------------------------------------------- */
/* TCP connection is ready. Do server side SSL. */
ssl = SSL_new(ctx);
CHK_NULL(ssl);
SSL_set_fd(ssl, sd);
err = SSL_accept(ssl);
CHK_SSL(err);
/* Get the cipher - opt */
printf("SSL connection using %s\n", SSL_get_cipher(ssl));
/* Get client's certificate (note: beware of dynamic allocation) - opt */
client_cert = SSL_get_peer_certificate(ssl);
if (client_cert != NULL) {
printf("Client certificate:\n");
str = X509_NAME_oneline(X509_get_subject_name(client_cert), 0, 0);
CHK_NULL(str);
printf("\t subject: %s\n", str);
OPENSSL_free(str);
str = X509_NAME_oneline(X509_get_issuer_name(client_cert), 0, 0);
CHK_NULL(str);
printf("\t issuer: %s\n", str);
OPENSSL_free(str);
/* We could do all sorts of certificate verification stuff here before
deallocating the certificate. */
X509_free(client_cert);
} else
printf("Client does not have certificate.\n");
/* DATA EXCHANGE - Receive message and send reply. */
err = SSL_read(ssl, buf, sizeof (buf) - 1);
CHK_SSL(err);
buf[err] = '\0';
printf("Got %d chars:'%s'\n", err, buf);
err = SSL_write(ssl, "I hear you.", strlen("I hear you."));
CHK_SSL(err);
/* Clean up. */
close(sd);
SSL_free(ssl);
SSL_CTX_free(ctx);
}
/* EOF - serv.cpp */
客户代码：
#include <stdio.h>
#include <memory.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <openssl/crypto.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
/* define HOME to be dir for key and cert files... */
#define HOME "./"
/* Make these what you want for cert & key files */
#define CERTF "/home/a.seifpour/Desktop/SSL Tutorial/cert.pem"
#define KEYF "/home/a.seifpour/Desktop/SSL Tutorial/key.pem"
#define CHK_NULL(x) if ((x)==NULL) exit (1)
#define CHK_ERR(err,s) if ((err)==-1) { perror(s); exit(1); }
#define CHK_SSL(err) if ((err)==-1) { ERR_print_errors_fp(stderr); exit(2); }
int main() {
int err;
int sd;
struct sockaddr_in sa;
SSL_CTX* ctx;
SSL* ssl;
X509* server_cert;
char* str;
char buf [4096];
const SSL_METHOD *meth;
OpenSSL_add_ssl_algorithms();
meth = TLSv1_2_client_method();
SSL_load_error_strings();
ctx = SSL_CTX_new(meth);
CHK_NULL(ctx);
// if (SSL_CTX_set_cipher_list(ctx, "ECDHE-ECDSA-AES256-GCM- SHA384") != 1)
// ERR_print_errors_fp(stderr);
/* ----------------------------------------------- */
/* Create a socket and connect to server using normal socket calls. */
sd = socket(AF_INET, SOCK_STREAM, 0);
CHK_ERR(sd, "socket");
memset(&sa, 0, sizeof (sa));
sa.sin_family = AF_INET;
sa.sin_addr.s_addr = inet_addr("127.0.0.1"); /* Server IP */
sa.sin_port = htons(9999); /* Server Port number */
err = connect(sd, (struct sockaddr*) &sa, sizeof (sa));
CHK_ERR(err, "connect");
/* ----------------------------------------------- */
/* Now we have TCP conncetion. Start SSL negotiation. */
ssl = SSL_new(ctx);
CHK_NULL(ssl);
SSL_set_fd(ssl, sd);
err = SSL_connect(ssl);
CHK_SSL(err);
/* Following two steps are optional and not required for
data exchange to be successful. */
/* Get the cipher - opt */
printf("SSL connection using %s\n", SSL_get_cipher(ssl));
/* Get server's certificate (note: beware of dynamic allocation) - opt */
server_cert = SSL_get_peer_certificate(ssl);
CHK_NULL(server_cert);
printf("Server certificate:\n");
str = X509_NAME_oneline(X509_get_subject_name(server_cert), 0, 0);
CHK_NULL(str);
printf("\t subject: %s\n", str);
OPENSSL_free(str);
str = X509_NAME_oneline(X509_get_issuer_name(server_cert), 0, 0);
CHK_NULL(str);
printf("\t issuer: %s\n", str);
OPENSSL_free(str);
/* We could do all sorts of certificate verification stuff here before
deallocating the certificate. */
X509_free(server_cert);
/* --------------------------------------------------- */
/* DATA EXCHANGE - Send a message and receive a reply. */
err = SSL_write(ssl, "Hello World!", strlen("Hello World!"));
CHK_SSL(err);
err = SSL_read(ssl, buf, sizeof (buf) - 1);
// err = recv(sd, buf, sizeof(buf), 0);
CHK_SSL(err);
buf[err] = '\0';
printf("Got %d chars:'%s'\n", err, buf);
SSL_shutdown(ssl); /* send SSL/TLS close_notify */
/* Clean up. */
// close(sd);
SSL_free(ssl);
SSL_CTX_free(ctx);
}
/* EOF - cli.cpp */
答案 0 :(得分：0)
ServerKeyExchange是为短暂的Diffie-Hellman协议发送的消息。您不需要更改代码，只需启用（仅限？）DHE和ECDHE密码套件即可。您的密码套件选择似乎超出了您提供的代码。
在您打开这些密码套件之前，请确保您了解对这些协议的攻击，例如： Logjam并且至少只允许安全的密钥大小。