ssl - SSL连接读取中的垃圾值

我使用SSL编写了我的第一个服务器客户端程序。我正在尝试在局域网中的两个桌面之间发送和接收一些数据。但是我在终端接收到垃圾值。请帮我。如果出错，SSL_write（）和SSL_read（）都将返回负值，这正是我的情况，而我显然不知道原因。在wireshark中，我可以看到TCP正在用于我们的通信中应该是SSL / TSLv1。下面是代码。

客户端

#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();
    }
    else
        puts("connection successful\n");
    return sd;
}

SSL_CTX* InitCTX(void)
{   SSL_METHOD *method;
    SSL_CTX *ctx;

    OpenSSL_add_all_algorithms();
    SSL_load_error_strings();
    method = SSLv3_client_method();
    ctx = SSL_CTX_new(method);
    if ( ctx == NULL )
    {
        ERR_print_errors_fp(stderr);
        abort();
    }
    return ctx;
}



int main(int count, char *strings[])
{   SSL_CTX *ctx;
    int server;
    SSL *ssl;
    char rcvbuf[1024];
    int byteswritten, bytesread;
    char *hostname, *portnum;
    char msgtobesent[100];
    if ( count != 3 )
    {
        printf("usage: %s <hostname> <portnum>\n", strings[0]);
        exit(0);
    }
    printf ("Message to be sent to the SSL server: ");
    fgets (msgtobesent, 100, stdin);
    SSL_library_init();
    hostname=strings[1];
    portnum=strings[2];
    ctx = InitCTX();
    server = OpenConnection(hostname, atoi(portnum));
    ssl = SSL_new(ctx);
    SSL_set_fd(ssl, server);
    if ( SSL_connect(ssl) == FAIL )
        ERR_print_errors_fp(stderr);
    else
    {
        printf("Connected with %s encryption\n", SSL_get_cipher(ssl));
        byteswritten = SSL_write(ssl, msgtobesent, strlen(msgtobesent));
        printf ("Written %d chars\n",byteswritten);
        bytesread = SSL_read(ssl, rcvbuf, sizeof(rcvbuf)-1);
        rcvbuf[bytesread] = '\0';
        printf ("Received %d chars: %s\n", bytesread, rcvbuf);
    }
SSL_free(ssl);
close(server);         /* close socket */
SSL_CTX_free(ctx);        /* release context */
return 0;
}

服务器

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

#define FAIL    -1

int OpenListener(int port)
{
    int sd;
    struct sockaddr_in addr;
    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 = INADDR_ANY;
    if ( bind(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0 )
    {
        perror("can't bind port");
        abort();
    }
    else
        puts("bind successful\n");
    if ( listen(sd, 10) != 0 )
    {
        perror("Can't configure listening port");
        abort();
    }
    else
        puts("listening successfully\n");
    return sd;
}

int isRoot()
{
    if (getuid() != 0)
    {
        return 0;
    }
    else
    {
        return 1;
    }

}

SSL_CTX* InitServerCTX(void)
{
    const SSL_METHOD *method;
    SSL_CTX *ctx;
    OpenSSL_add_all_algorithms();
    SSL_load_error_strings();   /
    method = SSLv3_server_method();
    ctx = SSL_CTX_new(method);
    if ( ctx == NULL )
    {
        ERR_print_errors_fp(stderr);
        abort();
    }
    return ctx;
}

int main(int count, char *strings[])
{
    SSL_CTX *ctx;
    int server, byteswritten, bytesread;
    char *portnum;
    char rcvbuf[1024];
    SSL *ssl;
    char *msgtobesent;
    if(!isRoot())
    {
        printf("This program must be run as root/sudo user!!");
        exit(0);
    }
    if ( count != 2 )
    {
        printf("Usage: %s <portnum>\n", strings[0]);
        exit(0);
    }
    SSL_library_init();
    portnum = strings[1];
    ctx = InitServerCTX();
    server = OpenListener(atoi(portnum));
    while (1)
    {   struct sockaddr_in addr;
        socklen_t len = sizeof(addr);
        int client = accept(server, (struct sockaddr*)&addr, &len);
        printf("Connection: %s:%d\n",inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
        ssl = SSL_new(ctx);
        SSL_set_fd(ssl, client);
        bytesread=   SSL_read(ssl, (void *)rcvbuf, sizeof(rcvbuf)-1);
        rcvbuf[bytesread]='\0';
        printf ("Received %d chars: %s\n", bytesread, (char *)rcvbuf);
        byteswritten = SSL_write(ssl, "this is from server", strlen("this is from server"));
       printf ("Written %d chars\n",byteswritten);

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

终端输出：

最佳答案

好的，朋友们，经过一些痛苦的浏览时间，现在我知道如何使用SSL。以下程序对我有用。

客户：

#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 = SSLv3_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("No certificates.\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 */
        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;
}

服务器：

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

#define FAIL    -1

int OpenListener(int port)
{   int sd;
    struct sockaddr_in addr;

    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 = INADDR_ANY;
    if ( bind(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0 )
    {
        perror("can't bind port");
        abort();
    }
    if ( listen(sd, 10) != 0 )
    {
        perror("Can't configure listening port");
        abort();
    }
    return sd;
}

int isRoot()
{
    if (getuid() != 0)
    {
        return 0;
    }
    else
    {
        return 1;
    }

}
SSL_CTX* InitServerCTX(void)
{   SSL_METHOD *method;
    SSL_CTX *ctx;

    OpenSSL_add_all_algorithms();  /* load & register all cryptos, etc. */
    SSL_load_error_strings();   /* load all error messages */
    method = SSLv3_server_method();  /* create new server-method instance */
    ctx = SSL_CTX_new(method);   /* create new context from method */
    if ( ctx == NULL )
    {
        ERR_print_errors_fp(stderr);
        abort();
    }
    return ctx;
}

void LoadCertificates(SSL_CTX* ctx, char* CertFile, char* KeyFile)
{
    /* set the local certificate from CertFile */
    if ( SSL_CTX_use_certificate_file(ctx, CertFile, SSL_FILETYPE_PEM) <= 0 )
    {
        ERR_print_errors_fp(stderr);
        abort();
    }
    /* set the private key from KeyFile (may be the same as CertFile) */
    if ( SSL_CTX_use_PrivateKey_file(ctx, KeyFile, SSL_FILETYPE_PEM) <= 0 )
    {
        ERR_print_errors_fp(stderr);
        abort();
    }
    /* verify private key */
    if ( !SSL_CTX_check_private_key(ctx) )
    {
        fprintf(stderr, "Private key does not match the public certificate\n");
        abort();
    }
}

void ShowCerts(SSL* ssl)
{   X509 *cert;
    char *line;

    cert = SSL_get_peer_certificate(ssl); /* Get certificates (if available) */
    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);
        line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
        printf("Issuer: %s\n", line);
        free(line);
        X509_free(cert);
    }
    else
        printf("No certificates.\n");
}

void Servlet(SSL* ssl) /* Serve the connection -- threadable */
{   char buf[1024];
    char reply[1024];
    int sd, bytes;
    const char* HTMLecho="<html><body><pre>%s</pre></body></html>\n\n";

    if ( SSL_accept(ssl) == FAIL )     /* do SSL-protocol accept */
        ERR_print_errors_fp(stderr);
    else
    {
        ShowCerts(ssl);        /* get any certificates */
        bytes = SSL_read(ssl, buf, sizeof(buf)); /* get request */
        if ( bytes > 0 )
        {
            buf[bytes] = 0;
            printf("Client msg: \"%s\"\n", buf);
            sprintf(reply, HTMLecho, buf);   /* construct reply */
            SSL_write(ssl, reply, strlen(reply)); /* send reply */
        }
        else
            ERR_print_errors_fp(stderr);
    }
    sd = SSL_get_fd(ssl);       /* get socket connection */
    SSL_free(ssl);         /* release SSL state */
    close(sd);          /* close connection */
}

int main(int count, char *strings[])
{   SSL_CTX *ctx;
    int server;
    char *portnum;

    if(!isRoot())
    {
        printf("This program must be run as root/sudo user!!");
        exit(0);
    }
    if ( count != 2 )
    {
        printf("Usage: %s <portnum>\n", strings[0]);
        exit(0);
    }
    SSL_library_init();

    portnum = strings[1];
    ctx = InitServerCTX();        /* initialize SSL */
    LoadCertificates(ctx, "mycert.pem", "mycert.pem"); /* load certs */
    server = OpenListener(atoi(portnum));    /* create server socket */
    while (1)
    {   struct sockaddr_in addr;
        socklen_t len = sizeof(addr);
        SSL *ssl;

        int client = accept(server, (struct sockaddr*)&addr, &len);  /* accept connection as usual */
        printf("Connection: %s:%d\n",inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
        ssl = SSL_new(ctx);              /* get new SSL state with context */
        SSL_set_fd(ssl, client);      /* set connection socket to SSL state */
        Servlet(ssl);         /* service connection */
    }
    close(server);          /* close server socket */
    SSL_CTX_free(ctx);         /* release context */
}

使用以下命令为您的项目生成.pem文件：

openssl req -x509 -nodes -days 365 -newkey rsa：1024 -keyout mycert.pem -out mycert.pem

关于ssl - SSL连接读取中的垃圾值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/27295256/