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Sourcecode: fetchmail version File versions

socket.c

/*
 * socket.c -- socket library functions
 *
 * Copyright 1998 by Eric S. Raymond.
 * For license terms, see the file COPYING in this directory.
 */

#include "config.h"
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <ctype.h> /* isspace() */
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif /* HAVE_MEMORY_H */
#include <sys/types.h>
#include <sys/stat.h>
#ifndef HAVE_NET_SOCKET_H
#include <sys/socket.h>
#else
#include <net/socket.h>
#endif
#include <sys/un.h>
#include <netinet/in.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include <netdb.h>
#if defined(STDC_HEADERS)
#include <stdlib.h>
#endif
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#if defined(HAVE_STDARG_H)
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include "socket.h"
#include "fetchmail.h"
#include "i18n.h"

/* Defines to allow BeOS and Cygwin to play nice... */
#ifdef __BEOS__
static char peeked;
#define fm_close(a)  closesocket(a)
#define fm_write(a,b,c)  send(a,b,c,0)
#define fm_peek(a,b,c)   recv(a,b,c,0)
#define fm_read(a,b,c)   recv(a,b,c,0)
#else
#define fm_close(a)  close(a)
#define fm_write(a,b,c)  write(a,b,c)
#define fm_peek(a,b,c)   recv(a,b,c, MSG_PEEK)
#ifdef __CYGWIN__
#define fm_read(a,b,c)   cygwin_read(a,b,c)
static ssize_t cygwin_read(int sock, void *buf, size_t count);
#else /* ! __CYGWIN__ */
#define fm_read(a,b,c)   read(a,b,c)
#endif /* __CYGWIN__ */
#endif

/* We need to define h_errno only if it is not already */
#ifndef h_errno

#ifdef HAVE_RES_SEARCH
/* some versions of FreeBSD should declare this but don't */
extern int h_errno;
#else
/* pretend we have h_errno to avoid some #ifdef's later */
static int h_errno;
#endif

#endif /* ndef h_errno */

extern int mailserver_socket_temp;  /* Socket to close if connect timeout */

#if NET_SECURITY
#include <net/security.h>
#endif /* NET_SECURITY */

#ifdef HAVE_SOCKETPAIR
char *const *parse_plugin(const char *plugin, const char *host, const char *service)
{     const char **argvec;
      const char *c, *p;
      char *cp, *plugin_copy;
      unsigned int plugin_copy_len;
      unsigned int plugin_offset = 0, plugin_copy_offset = 0;
      unsigned int i, s = 2 * sizeof(char*), host_count = 0, service_count = 0;
      unsigned int plugin_len = strlen(plugin);
      unsigned int host_len = strlen(host);
      unsigned int service_len = strlen(service);

      for (c = p = plugin; *c; c++)
      {     if (isspace(*c) && !isspace(*p))
                  s += sizeof(char*);
            if (*p == '%' && *c == 'h')
                  host_count++;
            if (*p == '%' && *c == 'p')
                  service_count++;
            p = c;
      }

      plugin_copy_len = plugin_len + host_len * host_count + service_len * service_count;
      plugin_copy = malloc(plugin_copy_len + 1);
      if (!plugin_copy)
      {
            report(stderr, GT_("fetchmail: malloc failed\n"));
            return NULL;
      }

      while (plugin_copy_offset < plugin_copy_len)
      {     if ((plugin[plugin_offset] == '%') && (plugin[plugin_offset + 1] == 'h'))
            {     strcpy(plugin_copy + plugin_copy_offset, host);
                  plugin_offset += 2;
                  plugin_copy_offset += host_len;
            }
            else if ((plugin[plugin_offset] == '%') && (plugin[plugin_offset + 1] == 'p'))
            {     strcpy(plugin_copy + plugin_copy_offset, service);
                  plugin_offset += 2;
                  plugin_copy_offset += service_len;
            }
            else
            {     plugin_copy[plugin_copy_offset] = plugin[plugin_offset];
                  plugin_offset++;
                  plugin_copy_offset++;
            }
      }
      plugin_copy[plugin_copy_len] = 0;

      argvec = malloc(s);
      if (!argvec)
      {
            report(stderr, GT_("fetchmail: malloc failed\n"));
            return NULL;
      }
      memset(argvec, 0, s);
      for (c = p = plugin_copy, i = 0; *c; c++)
      {     if ((!isspace(*c)) && (c == p ? 1 : isspace(*p))) {
                  argvec[i] = c;
                  i++;
            }
            p = c;
      }
      for (cp = plugin_copy; *cp; cp++)
      {     if (isspace(*cp))
                  *cp = 0;
      }
      return (char *const*)argvec;
}

static int handle_plugin(const char *host,
                   const char *service, const char *plugin)
/* get a socket mediated through a given external command */
{
    int fds[2];
    char *const *argvec;

    /*
     * The author of this code, Felix von Leitner <felix@convergence.de>, says:
     * he chose socketpair() instead of pipe() because socketpair creates 
     * bidirectional sockets while allegedly some pipe() implementations don't.
     */
    if (socketpair(AF_UNIX,SOCK_STREAM,0,fds))
    {
      report(stderr, GT_("fetchmail: socketpair failed\n"));
      return -1;
    }
    switch (fork()) {
      case -1:
            /* error */
            report(stderr, GT_("fetchmail: fork failed\n"));
            return -1;
            break;
      case 0:     /* child */
            /* fds[1] is the parent's end; close it for proper EOF
            ** detection */
            (void) close(fds[1]);
            if ( (dup2(fds[0],0) == -1) || (dup2(fds[0],1) == -1) ) {
                  report(stderr, GT_("dup2 failed\n"));
                  exit(1);
            }
            /* fds[0] is now connected to 0 and 1; close it */
            (void) close(fds[0]);
            if (outlevel >= O_VERBOSE)
                report(stderr, GT_("running %s (host %s service %s)\n"), plugin, host, service);
            argvec = parse_plugin(plugin,host,service);
            execvp(*argvec, argvec);
            report(stderr, GT_("execvp(%s) failed\n"), *argvec);
            exit(0);
            break;
      default:    /* parent */
            /* NOP */
            break;
    }
    /* fds[0] is the child's end; close it for proper EOF detection */
    (void) close(fds[0]);
    return fds[1];
}
#endif /* HAVE_SOCKETPAIR */

#ifdef __UNUSED__
#include <sys/time.h>

int SockCheckOpen(int fd)
/* poll given socket; is it selectable? */
{
    fd_set r, w, e;
    int rt;
    struct timeval tv;
  
    for (;;) 
    {
      FD_ZERO(&r); FD_ZERO(&w); FD_ZERO(&e);
      FD_SET(fd, &e);
    
      tv.tv_sec = 0; tv.tv_usec = 0;
      rt = select(fd+1, &r, &w, &e, &tv);
      if (rt == -1 && (errno != EAGAIN && errno != EINTR))
          return 0;
      if (rt != -1)
          return 1;
    }
}
#endif /* __UNUSED__ */

int UnixOpen(const char *path)
{
    int sock = -1;
    struct sockaddr_un ad;
    memset(&ad, 0, sizeof(ad));
    ad.sun_family = AF_UNIX;
    strncpy(ad.sun_path, path, sizeof(ad.sun_path)-1);

    sock = socket( AF_UNIX, SOCK_STREAM, 0 );
    if (sock < 0)
    {
      h_errno = 0;
      return -1;
    }

      /* Socket opened saved. Usefull if connect timeout 
       * because it can be closed.
       */
      mailserver_socket_temp = sock;
    
      if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
    {
      int olderr = errno;
      fm_close(sock);   /* don't use SockClose, no traffic yet */
      h_errno = 0;
      errno = olderr;
      sock = -1;
    }
      
      /* No connect timeout, then no need to set mailserver_socket_temp */
      mailserver_socket_temp = -1;

    return sock;
}

#if INET6_ENABLE
int SockOpen(const char *host, const char *service, const char *options,
           const char *plugin)
{
    struct addrinfo *ai, *ai0, req;
    int i;
#if NET_SECURITY
    void *request = NULL;
    int requestlen;
#endif /* NET_SECURITY */

#ifdef HAVE_SOCKETPAIR
    if (plugin)
      return handle_plugin(host,service,plugin);
#endif /* HAVE_SOCKETPAIR */
    memset(&req, 0, sizeof(struct addrinfo));
    req.ai_socktype = SOCK_STREAM;

    if (getaddrinfo(host, service, &req, &ai0)) {
      report(stderr, GT_("fetchmail: getaddrinfo(%s.%s)\n"), host,service);
      return -1;
    }

#if NET_SECURITY
    if (!options)
      requestlen = 0;
    else
      if (net_security_strtorequest((char *)options, &request, &requestlen))
          goto ret;

    i = inner_connect(ai0, request, requestlen, NULL, NULL, "fetchmail", NULL);
    if (request)
      free(request);

 ret:
#else /* NET_SECURITY */
#ifdef HAVE_INNER_CONNECT
    i = inner_connect(ai0, NULL, 0, NULL, NULL, "fetchmail", NULL);
    if (i >= 0)
      break;
#else

    i = -1;
    for (ai = ai0; ai; ai = ai->ai_next) {
      i = socket(ai->ai_family, ai->ai_socktype, 0);
      if (i < 0)
          continue;

      /* Socket opened saved. Usefull if connect timeout 
       * because it can be closed.
       */
      mailserver_socket_temp = i;

      if (connect(i, (struct sockaddr *) ai->ai_addr, ai->ai_addrlen) < 0) {
          fm_close(i);
          i = -1;
          continue;
      }
      
      /* No connect timeout, then no need to set mailserver_socket_temp */
      mailserver_socket_temp = -1;
      
      break;
    }

#endif
#endif /* NET_SECURITY */

    freeaddrinfo(ai0);

    return i;
}
#else /* INET6_ENABLE */
#ifndef HAVE_INET_ATON
#ifndef  INADDR_NONE
#ifdef   INADDR_BROADCAST
#define  INADDR_NONE    INADDR_BROADCAST
#else
#define      INADDR_NONE      -1
#endif
#endif
#endif /* HAVE_INET_ATON */

int SockOpen(const char *host, int clientPort, const char *options,
           const char *plugin)
{
    int sock = -1;      /* pacify -Wall */
#ifndef HAVE_INET_ATON
    unsigned long inaddr;
#endif /* HAVE_INET_ATON */
    struct sockaddr_in ad, **pptr;
    struct hostent *hp;

#ifdef HAVE_SOCKETPAIR
    if (plugin) {
      char buf[10];
#ifdef HAVE_SNPRINTF
      snprintf(buf, sizeof(buf),  /* Yeah, paranoic. So what? :P */
#else
      sprintf(buf,
#endif /* HAVE_SNPRINTF */
            "%d",clientPort);
      return handle_plugin(host,buf,plugin);
    }
#endif /* HAVE_SOCKETPAIR */

    memset(&ad, 0, sizeof(ad));
    ad.sin_family = AF_INET;

    /* we'll accept a quad address */
#ifndef HAVE_INET_ATON
    inaddr = inet_addr((char*)host);
    if (inaddr != INADDR_NONE)
    {
        memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
#else
    if (inet_aton(host, &ad.sin_addr))
    {
#endif /* HAVE_INET_ATON */
        ad.sin_port = htons(clientPort);

        sock = socket(AF_INET, SOCK_STREAM, 0);
        if (sock < 0)
        {
            h_errno = 0;
            return -1;
        }

            /* Socket opened saved. Usefull if connect timeout because
             * it can be closed
             */
            mailserver_socket_temp = sock;
            
        if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
        {
            int olderr = errno;
            fm_close(sock);   /* don't use SockClose, no traffic yet */
            h_errno = 0;
            errno = olderr;
            return -1;
        }

            /* No connect timeout, then no need to set mailserver_socket_temp */
            mailserver_socket_temp = -1;
            
#ifndef HAVE_INET_ATON
    }
#else
    }
#endif /* HAVE_INET_ATON */
    else {
        hp = gethostbyname((char*)host);

        if (hp == NULL)
      {
          errno = 0;
          return -1;
      }
      /*
       * Add a check to make sure the address has a valid IPv4 or IPv6
       * length.  This prevents buffer spamming by a broken DNS.
       */
      if(hp->h_length != 4 && hp->h_length != 8)
      {
          h_errno = errno = 0;
          report(stderr, 
               GT_("fetchmail: illegal address length received for host %s\n"),host);
          return -1;
      }
      /*
       * Try all addresses of a possibly multihomed host until we get
       * a successful connect or until we run out of addresses.
       */
      pptr = (struct sockaddr_in **)hp->h_addr_list;
      for(; *pptr != NULL; pptr++)
      {
          sock = socket(AF_INET, SOCK_STREAM, 0);
          if (sock < 0)
          {
            h_errno = 0;
            return -1;
          }

            /* Socket opened saved. Usefull if connect timeout because
             * it can be closed
             */
            mailserver_socket_temp = sock;
            
          ad.sin_port = htons(clientPort);
          memcpy(&ad.sin_addr, *pptr, sizeof(struct in_addr));
          if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) == 0) {
                  /* No connect timeout, then no need to set mailserver_socket_temp */
                  mailserver_socket_temp = -1;
                  break; /* success */
            }     
          fm_close(sock);     /* don't use SockClose, no traffic yet */
          memset(&ad, 0, sizeof(ad));
          ad.sin_family = AF_INET;
      }
      if(*pptr == NULL)
      {
          int olderr = errno;
          fm_close(sock);     /* don't use SockClose, no traffic yet */
          h_errno = 0;
          errno = olderr;
          return -1;
      }
    }

    return(sock);
}
#endif /* INET6_ENABLE */


#if defined(HAVE_STDARG_H)
int SockPrintf(int sock, const char* format, ...)
{
#else
int SockPrintf(sock,format,va_alist)
int sock;
char *format;
va_dcl {
#endif

    va_list ap;
    char buf[8192];

#if defined(HAVE_STDARG_H)
    va_start(ap, format) ;
#else
    va_start(ap);
#endif
#ifdef HAVE_VSNPRINTF
    vsnprintf(buf, sizeof(buf), format, ap);
#else
    vsprintf(buf, format, ap);
#endif
    va_end(ap);
    return SockWrite(sock, buf, strlen(buf));

}

#ifdef SSL_ENABLE
#include "openssl/ssl.h"
#include "openssl/err.h"
#include "openssl/pem.h"
#include "openssl/x509.h"

static      SSL_CTX *_ctx = NULL;
static      SSL *_ssl_context[FD_SETSIZE];

SSL   *SSLGetContext( int );
#endif /* SSL_ENABLE */

int SockWrite(int sock, char *buf, int len)
{
    int n, wrlen = 0;
#ifdef      SSL_ENABLE
    SSL *ssl;
#endif

    while (len)
    {
#ifdef SSL_ENABLE
      if( NULL != ( ssl = SSLGetContext( sock ) ) )
            n = SSL_write(ssl, buf, len);
      else
#endif /* SSL_ENABLE */
          n = fm_write(sock, buf, len);
        if (n <= 0)
            return -1;
        len -= n;
      wrlen += n;
      buf += n;
    }
    return wrlen;
}

int SockRead(int sock, char *buf, int len)
{
    char *newline, *bp = buf;
    int n;
    int maxavailable = 0;
#ifdef      SSL_ENABLE
    SSL *ssl;
#endif

    if (--len < 1)
      return(-1);
#ifdef __BEOS__
    if (peeked != 0){
        (*bp) = peeked;
        bp++;
        len--;
        peeked = 0;
    }
#endif        
    do {
      /* 
       * The reason for these gymnastics is that we want two things:
       * (1) to read \n-terminated lines,
       * (2) to return the true length of data read, even if the
       *     data coming in has embedded NULS.
       */
#ifdef      SSL_ENABLE
      if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
            /* Hack alert! */
            /* OK...  SSL_peek works a little different from MSG_PEEK
                  Problem is that SSL_peek can return 0 if there
                  is no data currently available.  If, on the other
                  hand, we loose the socket, we also get a zero, but
                  the SSL_read then SEGFAULTS!  To deal with this,
                  we'll check the error code any time we get a return
                  of zero from SSL_peek.  If we have an error, we bail.
                  If we don't, we read one character in SSL_read and
                  loop.  This should continue to work even if they
                  later change the behavior of SSL_peek
                  to "fix" this problem...  :-( */
            if ((n = SSL_peek(ssl, bp, len)) < 0) {
                  (void)SSL_get_error(ssl, n);
                  return(-1);
            }
            maxavailable = n;
            if( 0 == n ) {
                  /* SSL_peek says no data...  Does he mean no data
                  or did the connection blow up?  If we got an error
                  then bail! */
                  if( 0 != ( n = SSL_get_error(ssl, n) ) ) {
                        return -1;
                  }
                  /* We didn't get an error so read at least one
                        character at this point and loop */
                  n = 1;
                  /* Make sure newline start out NULL!
                   * We don't have a string to pass through
                   * the strchr at this point yet */
                  newline = NULL;
            } else if ((newline = memchr(bp, '\n', n)) != NULL)
                  n = newline - bp + 1;
            /* Matthias Andree: SSL_read can return 0, in that case
             * we must cal SSL_get_error to figure if there was
             * an error or just a "no data" condition */
            if ((n = SSL_read(ssl, bp, n)) <= 0) {
                  if ((n = SSL_get_error(ssl, n))) {
                        return(-1);
                  }
            }
            /* Check for case where our single character turned out to
             * be a newline...  (It wasn't going to get caught by
             * the strchr above if it came from the hack...  ). */
            if( NULL == newline && 1 == n && '\n' == *bp ) {
                  /* Got our newline - this will break
                        out of the loop now */
                  newline = bp;
            }
      }
      else
#endif /* SSL_ENABLE */
      {

#ifdef __BEOS__
          if ((n = fm_read(sock, bp, 1)) <= 0)
#else
          if ((n = fm_peek(sock, bp, len)) <= 0)
#endif
            return (-1);
          maxavailable = n;
          if ((newline = memchr(bp, '\n', n)) != NULL)
            n = newline - bp + 1;
#ifndef __BEOS__
          if ((n = fm_read(sock, bp, n)) == -1)
            return(-1);
#endif /* __BEOS__ */
      }
      bp += n;
      len -= n;
    } while 
          (!newline && len);
    *bp = '\0';

#ifdef FORCE_STUFFING         /* too ugly to live -- besides, there's IMAP */
    /* OK, very weird hack coming up here:
     * When POP3 servers send us a message, they're supposed to
     * terminate the message with a line containing only a dot. To protect
     * against lines in the real message that might contain only a dot,
     * they're supposed to preface any line that starts with a dot with
     * an additional dot, which will be removed on the client side. That
     * process, called byte-stuffing (and unstuffing) is really not the
     * concern of this low-level routine, ordinarily, but there are some
     * POP servers (and maybe IMAP servers too, who knows) that fail to
     * do the byte-stuffing, and this routine is the best place to try to
     * identify and fix that fault.
     *
     * Since the DOT line is supposed to come only at the end of a
     * message, the implication is that right after we see it, the server
     * is supposed to go back to waiting for the next command. There
     * isn't supposed to be any more data to read after we see the dot.
     * THEREFORE, if we see more data to be read after something that
     * looks like the dot line, then probably the server is failing to
     * do byte-stuffing. In that case, we'll byte-pack it for them so
     * that the higher-level routines see things as hunky-dorey.
     * This is not a perfect test or fix by any means (it has an
     * obvious race condition, for one thing), but it should at least
     * reduce the nastiness that ensues when people don't know how
     * to write POP servers.
     */
    if ((maxavailable > (bp-buf)) &&
          ((((bp-buf) == 3) &&
            (buf[0] == '.') &&
            (buf[1] == '\r') &&
            (buf[2] == '\n')) ||
           (((bp-buf) == 2) &&
            (buf[0] == '.') &&
            (buf[1] == '\n')))) {

      memmove(buf+1, buf, (bp-buf)+1);
      buf[0] = '.';
      bp++;
    }
#endif /* FORCE_STUFFING */
    return bp - buf;
}

int SockPeek(int sock)
/* peek at the next socket character without actually reading it */
{
    int n;
    char ch;
#ifdef      SSL_ENABLE
    SSL *ssl;
#endif

#ifdef      SSL_ENABLE
      if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
            n = SSL_peek(ssl, &ch, 1);
            if (n < 0) {
                  (void)SSL_get_error(ssl, n);
                  return -1;
            }
            if( 0 == n ) {
                  /* This code really needs to implement a "hold back"
                   * to simulate a functioning SSL_peek()...  sigh...
                   * Has to be coordinated with the read code above.
                   * Next on the list todo...   */

                  /* SSL_peek says 0...  Does that mean no data
                  or did the connection blow up?  If we got an error
                  then bail! */
                  if( 0 != ( n = SSL_get_error(ssl, n) ) ) {
                        return -1;
                  }

                  /* Haven't seen this case actually occur, but...
                     if the problem in SockRead can occur, this should
                     be possible...  Just not sure what to do here.
                     This should be a safe "punt" the "peek" but don't
                     "punt" the "session"... */

                  return 0;   /* Give him a '\0' character */
            }
      }
      else
#endif /* SSL_ENABLE */
          n = fm_peek(sock, &ch, 1);
      if (n == -1)
            return -1;

#ifdef __BEOS__
    peeked = ch;
#endif
    return(ch);
}

#ifdef SSL_ENABLE

static      char *_ssl_server_cname = NULL;
static      int _check_fp;
static      char *_check_digest;
static      char *_server_label;
static      int _depth0ck;

SSL *SSLGetContext( int sock )
{
      /* If SSLOpen has never initialized - just return NULL */
      if( NULL == _ctx )
            return NULL;

      if( sock < 0 || sock > FD_SETSIZE )
            return NULL;
      return _ssl_context[sock];
}


int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
{
      char buf[257];
      X509 *x509_cert;
      int err, depth;
      unsigned char digest[EVP_MAX_MD_SIZE];
      char text[EVP_MAX_MD_SIZE * 3 + 1], *tp, *te;
      EVP_MD *digest_tp;
      unsigned int dsz, i, esz;
      X509_NAME *subj, *issuer;

      x509_cert = X509_STORE_CTX_get_current_cert(ctx);
      err = X509_STORE_CTX_get_error(ctx);
      depth = X509_STORE_CTX_get_error_depth(ctx);

      subj = X509_get_subject_name(x509_cert);
      issuer = X509_get_issuer_name(x509_cert);

      if (depth == 0) {
            _depth0ck = 1;
            
            if (outlevel == O_VERBOSE) {
                  if ((i = X509_NAME_get_text_by_NID(issuer, NID_organizationName, buf, sizeof(buf))) != -1) {
                        report(stdout, GT_("Issuer Organization: %s\n"), buf);
                        if (i >= sizeof(buf) - 1)
                              report(stdout, GT_("Warning: Issuer Organization Name too long (possibly truncated).\n"));
                  } else
                        report(stdout, GT_("Unknown Organization\n"));
                  if ((i = X509_NAME_get_text_by_NID(issuer, NID_commonName, buf, sizeof(buf))) != -1) {
                        report(stdout, GT_("Issuer CommonName: %s\n"), buf);
                        if (i >= sizeof(buf) - 1)
                              report(stdout, GT_("Warning: Issuer CommonName too long (possibly truncated).\n"));
                  } else
                        report(stdout, GT_("Unknown Issuer CommonName\n"));
            }
            if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) {
                  if (outlevel == O_VERBOSE)
                        report(stdout, GT_("Server CommonName: %s\n"), buf);
                  if (i >= sizeof(buf) - 1) {
                        /* Possible truncation. In this case, this is a DNS name, so this
                         * is really bad. We do not tolerate this even in the non-strict case. */
                        report(stderr, GT_("Bad certificate: Subject CommonName too long!\n"));
                        return (0);
                  }
                  if (_ssl_server_cname != NULL) {
                        char *p1 = buf;
                        char *p2 = _ssl_server_cname;
                        int n;
                        
                        if (*p1 == '*') {
                              ++p1;
                              n = strlen(p2) - strlen(p1);
                              if (n >= 0)
                                    p2 += n;
                        }     
                        if (0 != strcasecmp(p1, p2)) {
                              report(stderr,
                                  GT_("Server CommonName mismatch: %s != %s\n"),
                                  buf, _ssl_server_cname );
                              if (ok_return && strict)
                                    return (0);
                        }
                  } else if (ok_return && strict) {
                        report(stderr, GT_("Server name not set, could not verify certificate!\n"));
                        return (0);
                  }
            } else {
                  if (outlevel == O_VERBOSE)
                        report(stdout, GT_("Unknown Server CommonName\n"));
                  if (ok_return && strict) {
                        report(stderr, GT_("Server name not specified in certificate!\n"));
                        return (0);
                  }
            }
            /* Print the finger print. Note that on errors, we might print it more than once
             * normally; we kluge around that by using a global variable. */
            if (_check_fp) {
                  _check_fp = 0;
                  digest_tp = EVP_md5();
                  if (digest_tp == NULL) {
                        report(stderr, GT_("EVP_md5() failed!\n"));
                        return (0);
                  }
                  if (!X509_digest(x509_cert, digest_tp, digest, &dsz)) {
                        report(stderr, GT_("Out of memory!\n"));
                        return (0);
                  }
                  tp = text;
                  te = text + sizeof(text);
                  for (i = 0; i < dsz; i++) {
#ifdef HAVE_SNPRINTF
                        esz = snprintf(tp, te - tp, i > 0 ? ":%02X" : "%02X", digest[i]);
#else
                        esz = sprintf(tp, i > 0 ? ":%02X" : "%02X", digest[i]);
#endif
                        if (esz >= te - tp) {
                              report(stderr, GT_("Digest text buffer too small!\n"));
                              return (0);
                        }
                        tp += esz;
                  }
                  if (outlevel > O_NORMAL)
                      report(stdout, GT_("%s key fingerprint: %s\n"), _server_label, text);
                  if (_check_digest != NULL) {
                        if (strcmp(text, _check_digest) == 0) {
                            if (outlevel > O_NORMAL)
                              report(stdout, GT_("%s fingerprints match.\n"), _server_label);
                        } else {
                            if (outlevel > O_SILENT)
                              report(stderr, GT_("%s fingerprints do not match!\n"), _server_label);
                            return (0);
                        }
                  }
            }
      }

      if (err != X509_V_OK && (strict || outlevel == O_VERBOSE)) {
            report(strict ? stderr : stdout, GT_("Warning: server certificate verification: %s\n"), X509_verify_cert_error_string(err));
            /* We gave the error code, but maybe we can add some more details for debugging */
            switch (err) {
            case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
                  X509_NAME_oneline(issuer, buf, sizeof(buf));
                  buf[sizeof(buf) - 1] = '\0';
                  report(stdout, GT_("unknown issuer (first %d characters): %s\n"), sizeof(buf), buf);
                  break;
            }
      }
      if (!strict)
            ok_return = 1;
      return (ok_return);
}

int SSL_nock_verify_callback( int ok_return, X509_STORE_CTX *ctx )
{
      return SSL_verify_callback(ok_return, ctx, 0);
}

int SSL_ck_verify_callback( int ok_return, X509_STORE_CTX *ctx )
{
      return SSL_verify_callback(ok_return, ctx, 1);
}

/* performs initial SSL handshake over the connected socket
 * uses SSL *ssl global variable, which is currently defined
 * in this file
 */
int SSLOpen(int sock, char *mycert, char *mykey, char *myproto, int certck, char *certpath,
    char *fingerprint, char *servercname, char *label)
{
      SSL *ssl;
        struct stat randstat;
        int i;
      
      SSL_load_error_strings();
      SSLeay_add_ssl_algorithms();
      
#ifdef SSL_ENABLE
        if (stat("/dev/random", &randstat)  &&
            stat("/dev/urandom", &randstat)) {
          /* Neither /dev/random nor /dev/urandom are present, so add
             entropy to the SSL PRNG a hard way. */
          for (i = 0; i < 10000  &&  ! RAND_status (); ++i) {
            char buf[4];
            struct timeval tv;
            gettimeofday (&tv, 0);
            buf[0] = tv.tv_usec & 0xF;
            buf[2] = (tv.tv_usec & 0xF0) >> 4;
            buf[3] = (tv.tv_usec & 0xF00) >> 8;
            buf[1] = (tv.tv_usec & 0xF000) >> 12;
            RAND_add (buf, sizeof buf, 0.1);
          }
        }
#endif /* SSL_ENABLE */


      if( sock < 0 || sock > FD_SETSIZE ) {
            report(stderr, GT_("File descriptor out of range for SSL") );
            return( -1 );
      }

      if( ! _ctx ) {
            /* Be picky and make sure the memory is cleared */
            memset( _ssl_context, 0, sizeof( _ssl_context ) );
            if(myproto) {
                  if(!strcmp("ssl2",myproto)) {
                        _ctx = SSL_CTX_new(SSLv2_client_method());
                  } else if(!strcmp("ssl3",myproto)) {
                        _ctx = SSL_CTX_new(SSLv3_client_method());
                  } else if(!strcmp("tls1",myproto)) {
                        _ctx = SSL_CTX_new(TLSv1_client_method());
                  } else if (!strcmp("ssl23",myproto)) {
                        myproto = NULL;
                  } else {
                        fprintf(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
                        myproto = NULL;
                  }
            }
            if(!myproto) {
                  _ctx = SSL_CTX_new(SSLv23_client_method());
            }
            if(_ctx == NULL) {
                  ERR_print_errors_fp(stderr);
                  return(-1);
            }
      }

      if (certck) {
            SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER, SSL_ck_verify_callback);
            if (certpath)
                  SSL_CTX_load_verify_locations(_ctx, NULL, certpath);
      } else {
            /* In this case, we do not fail if verification fails. However,
             *  we provide the callback for output and possible fingerprint checks. */
            SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER, SSL_nock_verify_callback);
      }
      
      _ssl_context[sock] = SSL_new(_ctx);
      
      if(_ssl_context[sock] == NULL) {
            ERR_print_errors_fp(stderr);
            return(-1);
      }
      
      /* This static is for the verify callback */
      _ssl_server_cname = servercname;
      _server_label = label;
      _check_fp = 1;
      _check_digest = fingerprint;
      _depth0ck = 0;

      if( mycert || mykey ) {

      /* Ok...  He has a certificate file defined, so lets declare it.  If
       * he does NOT have a separate certificate and private key file then
       * assume that it's a combined key and certificate file.
       */
            if( !mykey )
                  mykey = mycert;
            if( !mycert )
                  mycert = mykey;
            SSL_use_certificate_file(_ssl_context[sock], mycert, SSL_FILETYPE_PEM);
            SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM);
      }

      SSL_set_fd(_ssl_context[sock], sock);
      
      if(SSL_connect(_ssl_context[sock]) < 1) {
            ERR_print_errors_fp(stderr);
            return(-1);
      }

      /* Paranoia: was the callback not called as we expected? */
      if ((fingerprint != NULL || certck) && !_depth0ck) {
            report(stderr, GT_("Certificate/fingerprint verification was somehow skipped!\n"));
            
            if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
                  /* Clean up the SSL stack */
                  SSL_free( _ssl_context[sock] );
                  _ssl_context[sock] = NULL;
            }
            return(-1);
      }

      return(0);
}
#endif

int SockClose(int sock)
/* close a socket gracefully */
{
#ifdef      SSL_ENABLE
    SSL *ssl;

    if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
        /* Clean up the SSL stack */
        SSL_free( _ssl_context[sock] );
        _ssl_context[sock] = NULL;
    }
#endif

#ifdef __UNUSED__
    /* 
     * This hangs in RedHat 6.2 after fetchmail runs for a while a
     * FIN_WAIT2 comes up in netstat and fetchmail never returns from
     * the recv system call. (Reported from jtnews
     * <jtnews@bellatlantic.net>, Wed, 24 May 2000 21:26:02.)
     *
     * Half-close the connection first so the other end gets notified.
     *
     * This stops sends but allows receives (effectively, it sends a
     * TCP <FIN>).  */
    if (shutdown(sock, 1) == 0) {
      char ch;
      /* If there is any data still waiting in the queue, discard it.
       * Call recv() until either it returns 0 (meaning we received a FIN)
       * or any error occurs.  This makes sure all data sent by the other
       * side is acknowledged at the TCP level.
       */
      if (fm_peek(sock, &ch, 1) > 0)
          while (fm_read(sock, &ch, 1) > 0)
            continue;
    }
#endif /* __UNUSED__ */

    /* if there's an error closing at this point, not much we can do */
    return(fm_close(sock));   /* this is guarded */
}

#ifdef __CYGWIN__
/*
 * Workaround Microsoft Winsock recv/WSARecv(..., MSG_PEEK) bug.
 * See http://sources.redhat.com/ml/cygwin/2001-08/msg00628.html
 * for more details.
 */
static ssize_t cygwin_read(int sock, void *buf, size_t count)
{
    char *bp = buf;
    int n = 0;

    if ((n = read(sock, bp, count)) == -1)
      return(-1);

    if (n != count) {
      int n2 = 0;
      if (outlevel >= O_VERBOSE)
          report(stdout, GT_("Cygwin socket read retry\n"));
      n2 = read(sock, bp + n, count - n);
      if (n2 == -1 || n + n2 != count) {
          report(stderr, GT_("Cygwin socket read retry failed!\n"));
          return(-1);
      }
    }

    return count;
}
#endif /* __CYGWIN__ */

#ifdef MAIN
/*
 * Use the chargen service to test input buffering directly.
 * You may have to uncomment the `chargen' service description in your
 * inetd.conf (and then SIGHUP inetd) for this to work.  */
main()
{
    int           sock = SockOpen("localhost", 19, NULL);
    char    buf[80];

    while (SockRead(sock, buf, sizeof(buf)-1))
      SockWrite(1, buf, strlen(buf));
    SockClose(sock);
}
#endif /* MAIN */

/* socket.c ends here */

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