#include "common.h"int tcp_connect(host,port)  char *host;  int port;  {    struct hostent *hp;    struct sockaddr_in addr;    int sock;        if(!(hp=gethostbyname(host)))      berr_exit("Couldn't resolve host");    memset(&addr,0,sizeof(addr));    addr.sin_addr=*(struct in_addr*)      hp->h_addr_list[0];    addr.sin_family=AF_INET;    addr.sin_port=htons(port);    if((sock=socket(AF_INET,SOCK_STREAM,      IPPROTO_TCP))<0)      err_exit("Couldn't create socket");    if(connect(sock,(struct sockaddr *)&addr,      sizeof(addr))<0)      err_exit("Couldn't connect socket");        return sock;  }/* Check that the common name matches the   host name*/void check_cert(ssl,host)  SSL *ssl;  char *host;  {    X509 *peer;    char peer_CN[256];        if(SSL_get_verify_result(ssl)!=X509_V_OK)      berr_exit("Certificate doesn't verify");    /*Check the cert chain. The chain length      is automatically checked by OpenSSL when      we set the verify depth in the ctx */    /*Check the common name*/    peer=SSL_get_peer_certificate(ssl);    X509_NAME_get_text_by_NID      (X509_get_subject_name(peer),      NID_commonName, peer_CN, 256);    if(strcasecmp(peer_CN,host))    err_exit      ("Common name doesn't match host name");  }