如何在openssl

Question

我正在编写一个响应传入TLS心跳请求的TLS服务器。 我正在使用 OpenSSL 1.0.2g 。

以下是我的服务器代码（从openssl / demos / ssl修改）

#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>       /* SSLeay stuff */
#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 "/home/kbhatk/CLionProjects/tlsHeartbeat/"
/* Make these what you want for cert & key files */
#define CERTF  HOME "foo-cert.pem"
#define KEYF  HOME  "foo-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;
    socklen_t 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();
    SSLeay_add_ssl_algorithms();
    meth = SSLv23_server_method();
    ctx = SSL_CTX_new (meth);
    if (!ctx) {
        ERR_print_errors_fp(stderr);
        exit(2);
    }

    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);
    }

    /* ----------------------------------------------- */
    /* 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 (9393);          /* 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. */

    for(;;)
        ;
    close (sd);
    SSL_free (ssl);
    SSL_CTX_free (ctx);
}
/* EOF - serv.cpp */

我的客户代码

#include <stdio.h>
#include <memory.h>
#include <unistd.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 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;

    SSLeay_add_ssl_algorithms();
    meth = SSLv23_client_method();
    SSL_load_error_strings();
    ctx = SSL_CTX_new (meth);                        CHK_NULL(ctx);

    CHK_SSL(err);

    /* ----------------------------------------------- */
    /* 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     (9393);          /* 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);
    SSL_heartbeat(ssl);
    err = SSL_read (ssl, buf, sizeof(buf) - 1);                     CHK_SSL(err);
    buf[err] = '\0';
    printf ("Got %d chars:'%s'\n", err, buf);
    //wait
    for(;;) ;

    SSL_shutdown (ssl);  /* send SSL/TLS close_notify */

    /* Clean up. */

    close(sd);
    SSL_free (ssl);
    SSL_CTX_free (ctx);
}

我看到我的客户端正在发送TLS听力，但服务器没有通过wireshark捕获对它进行响应。

我看不到关于如何响应TLS心跳的示例（我天真地希望这是由openssl自动完成的，从这里读取的轻量代码t1_lib.c tls1_process_heartbeat，它甚至看起来如此）。

所以有人可以帮助我理解服务器应该如何响应TLS听力？

PS：是的，我知道使用TLS心跳可能不是一个好主意（甚至在更高版本的OpesSSL中删除），TCP保持活着可能是更好的选择，但我没有目前在这个问题上的选择。

谢谢， Keshava。