]> Pileus Git - ~andy/fetchmail/blobdiff - socket.c
Credit John Beck's fixes.
[~andy/fetchmail] / socket.c
index 94d3e56b0a8a99be3fc96bb3d357e92c79e883d6..58a8e15e807e4258a717933b5603da522c08473f 100644 (file)
--- a/socket.c
+++ b/socket.c
@@ -1,6 +1,7 @@
 /*
  * socket.c -- socket library functions
  *
+ * Copyright 1998 by Eric S. Raymond.
  * For license terms, see the file COPYING in this directory.
  */
 
@@ -8,13 +9,22 @@
 #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>
 #else
 #include <varargs.h>
 #endif
-#include "socket.h"
-#include "fetchmail.h"
-
-#ifdef HAVE_RES_SEARCH
-/* some versions of FreeBSD should declare this but don't */
-extern int h_errno;
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
 #else
-/* pretend we have h_errno to avoid some #ifdef's later */
-static int h_errno;
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
 #endif
 
-#if NET_SECURITY
-#include <net/security.h>
-#endif /* NET_SECURITY */
+#include "socket.h"
+#include "fetchmail.h"
+#include "getaddrinfo.h"
+#include "i18n.h"
+#include "sdump.h"
 
-#if INET6
-int SockOpen(const char *host, const char *service, const char *options)
-{
-  int i;
-  struct addrinfo *ai, req;
-#if NET_SECURITY
-  void *request = NULL;
-  int requestlen;
-#endif /* NET_SECURITY */
-
-  memset(&req, 0, sizeof(struct addrinfo));
-  req.ai_socktype = SOCK_STREAM;
-
-  if (i = getaddrinfo(host, service, &req, &ai)) {
-    error(0, 0, "fetchmail: getaddrinfo(%s.%s): %s(%d)", host, service, gai_strerror(i), i);
-    return -1;
-  };
-
-#if NET_SECURITY
-  if (!options)
-    requestlen = 0;
-  else
-    if (net_security_strtorequest((char *)options, &request, &requestlen))
-      goto ret;
-
-  i = inner_connect(ai, request, requestlen, NULL, NULL, "fetchmail", NULL);
-  if (request)
-    free(request);
-
-ret:
-#else /* NET_SECURITY */
-  i = inner_connect(ai, NULL, 0, NULL, NULL, "fetchmail", NULL);
-#endif /* NET_SECURITY */
-
-  freeaddrinfo(ai);
-
-  return i;
-};
-#else /* INET6 */
-#ifndef HAVE_INET_ATON
-#ifndef  INADDR_NONE
-#ifdef   INADDR_BROADCAST
-#define  INADDR_NONE   INADDR_BROADCAST
+/* 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         INADDR_NONE    -1
-#endif
+#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
-#endif /* HAVE_INET_ATON */
 
-int SockOpen(const char *host, int clientPort, const char *options)
+/* We need to define h_errno only if it is not already */
+#ifndef h_errno
+# if !HAVE_DECL_H_ERRNO
+extern int h_errno;
+# endif
+#endif /* ndef h_errno */
+
+#ifdef HAVE_SOCKETPAIR
+static char *const *parse_plugin(const char *plugin, const char *host, const char *service)
 {
-    int sock;
-#ifndef HAVE_INET_ATON
-    unsigned long inaddr;
-#endif /* HAVE_INET_ATON */
-    struct sockaddr_in ad;
-    struct hostent *hp;
+       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);
 
-    memset(&ad, 0, sizeof(ad));
-    ad.sin_family = AF_INET;
-
-    /* we'll accept a quad address */
-#ifndef HAVE_INET_ATON
-    inaddr = inet_addr(host);
-    if (inaddr != INADDR_NONE)
-        memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
-    else
-#else
-    if (!inet_aton(host, &ad.sin_addr))
-#endif /* HAVE_INET_ATON */
-    {
-        hp = gethostbyname(host);
+       for (c = p = plugin; *c; c++)
+       {       if (isspace((unsigned char)*c) && !isspace((unsigned char)*p))
+                       s += sizeof(char*);
+               if (*p == '%' && *c == 'h')
+                       host_count++;
+               if (*p == '%' && *c == 'p')
+                       service_count++;
+               p = c;
+       }
 
-        if (hp == NULL)
+       plugin_copy_len = plugin_len + host_len * host_count + service_len * service_count;
+       plugin_copy = (char *)malloc(plugin_copy_len + 1);
+       if (!plugin_copy)
        {
-           errno = 0;
-           return -1;
+               report(stderr, GT_("fetchmail: malloc failed\n"));
+               return NULL;
        }
-       /*
-        * 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)
+
+       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 = (char **)malloc(s);
+       if (!argvec)
        {
-           h_errno = errno = 0;
-           error(0, 0, "fetchmail: illegal address length received for host %s");
-           return -1;
+               free(plugin_copy);
+               report(stderr, GT_("fetchmail: malloc failed\n"));
+               return NULL;
        }
-       /*
-        * FIXME: make this work for multihomed hosts.
-        * We're toast if we get back multiple addresses and h_addrs[0]
-        * (aka h_addr) is not one we can actually connect to; this happens
-        * with multi-homed boxen.
-        */
-        memcpy(&ad.sin_addr, hp->h_addr, hp->h_length);
+       memset(argvec, 0, s);
+       for (p = cp = plugin_copy, i = 0; *cp; cp++)
+       {       if ((!isspace((unsigned char)*cp)) && (cp == p ? 1 : isspace((unsigned char)*p))) {
+                       argvec[i] = cp;
+                       i++;
+               }
+               p = cp;
+       }
+       for (cp = plugin_copy; *cp; cp++)
+       {       if (isspace((unsigned char)*cp))
+                       *cp = 0;
+       }
+       return 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;
+       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(EXIT_FAILURE);
+               }
+               /* 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);
+               if (argvec == NULL)
+                       _exit(EXIT_FAILURE);
+               execvp(*argvec, argvec);
+               report(stderr, GT_("execvp(%s) failed\n"), *argvec);
+               _exit(EXIT_FAILURE);
+               break;
+       default:        /* parent */
+               /* NOP */
+               break;
     }
-    ad.sin_port = htons(clientPort);
-    
-    sock = socket(AF_INET, SOCK_STREAM, 0);
+    /* fds[0] is the child's end; close it for proper EOF detection */
+    (void) close(fds[0]);
+    return fds[1];
+}
+#endif /* HAVE_SOCKETPAIR */
+
+/** Set socket to SO_KEEPALIVE. \return 0 for success. */
+int SockKeepalive(int sock) {
+    int keepalive = 1;
+    return setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, &keepalive, sizeof keepalive);
+}
+
+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;
+       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;
-       close(sock);
+       fm_close(sock); /* don't use SockClose, no traffic yet */
        h_errno = 0;
        errno = olderr;
-        return -1;
+       sock = -1;
     }
 
-    return(sock);
+    /* No connect timeout, then no need to set mailserver_socket_temp */
+    mailserver_socket_temp = -1;
+
+    return sock;
+}
+
+int SockOpen(const char *host, const char *service,
+            const char *plugin, struct addrinfo **ai0)
+{
+    struct addrinfo *ai, req;
+    int i, acterr = 0;
+    int ord;
+    char errbuf[8192] = "";
+
+#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;
+#ifdef AI_ADDRCONFIG
+    req.ai_flags = AI_ADDRCONFIG;
+#endif
+
+    i = fm_getaddrinfo(host, service, &req, ai0);
+    if (i) {
+       report(stderr, GT_("getaddrinfo(\"%s\",\"%s\") error: %s\n"),
+               host, service, gai_strerror(i));
+       if (i == EAI_SERVICE)
+           report(stderr, GT_("Try adding the --service option (see also FAQ item R12).\n"));
+       return -1;
+    }
+
+    /* NOTE a Linux bug here - getaddrinfo will happily return 127.0.0.1
+     * twice if no IPv6 is configured */
+    i = -1;
+    for (ord = 0, ai = *ai0; ai; ord++, ai = ai->ai_next) {
+       char buf[256]; /* hostname */
+       char pb[256];  /* service name */
+       int gnie;      /* getnameinfo result code */
+
+       gnie = getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof(buf), NULL, 0, NI_NUMERICHOST);
+       if (gnie)
+           snprintf(buf, sizeof(buf), GT_("unknown (%s)"), gai_strerror(gnie));
+       gnie = getnameinfo(ai->ai_addr, ai->ai_addrlen, NULL, 0, pb, sizeof(pb), NI_NUMERICSERV);
+       if (gnie)
+           snprintf(pb, sizeof(pb), GT_("unknown (%s)"), gai_strerror(gnie));
+
+       if (outlevel >= O_VERBOSE)
+           report_build(stdout, GT_("Trying to connect to %s/%s..."), buf, pb);
+       i = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+       if (i < 0) {
+           int e = errno;
+           /* mask EAFNOSUPPORT errors, they confuse users for
+            * multihomed hosts */
+           if (errno != EAFNOSUPPORT)
+               acterr = errno;
+           if (outlevel >= O_VERBOSE)
+               report_complete(stdout, GT_("cannot create socket: %s\n"), strerror(e));
+           snprintf(errbuf+strlen(errbuf), sizeof(errbuf)-strlen(errbuf),\
+                    GT_("name %d: cannot create socket family %d type %d: %s\n"), ord, ai->ai_family, ai->ai_socktype, strerror(e));
+           continue;
+       }
+
+       SockKeepalive(i);
+
+       /* Save socket descriptor.
+        * Used to close the socket after connect timeout. */
+       mailserver_socket_temp = i;
+
+       if (connect(i, (struct sockaddr *) ai->ai_addr, ai->ai_addrlen) < 0) {
+           int e = errno;
+
+           /* additionally, suppress IPv4 network unreach errors */
+           if (e != EAFNOSUPPORT)
+               acterr = errno;
+
+           if (outlevel >= O_VERBOSE)
+               report_complete(stdout, GT_("connection failed.\n"));
+           if (outlevel >= O_VERBOSE)
+               report(stderr, GT_("connection to %s:%s [%s/%s] failed: %s.\n"), host, service, buf, pb, strerror(e));
+           snprintf(errbuf+strlen(errbuf), sizeof(errbuf)-strlen(errbuf), GT_("name %d: connection to %s:%s [%s/%s] failed: %s.\n"), ord, host, service, buf, pb, strerror(e));
+           fm_close(i);
+           i = -1;
+           continue;
+       } else {
+           if (outlevel >= O_VERBOSE)
+               report_complete(stdout, GT_("connected.\n"));
+       }
+
+       /* No connect timeout, then no need to set mailserver_socket_temp */
+       mailserver_socket_temp = -1;
+
+       break;
+    }
+
+    fm_freeaddrinfo(*ai0);
+    *ai0 = NULL;
+
+    if (i == -1) {
+       report(stderr, GT_("Connection errors for this poll:\n%s"), errbuf);
+       errno = acterr;
+    }
+
+    return i;
 }
-#endif /* INET6 */
 
 
 #if defined(HAVE_STDARG_H)
@@ -178,23 +365,54 @@ va_dcl {
 #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));
 
 }
 
-int SockWrite(int sock, char *buf, int len)
+#ifdef SSL_ENABLE
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#include <openssl/x509v3.h>
+#include <openssl/rand.h>
+
+static void report_SSL_errors(FILE *stream)
+{
+    unsigned long err;
+
+    while (0ul != (err = ERR_get_error())) {
+       char *errstr = ERR_error_string(err, NULL);
+       report(stream, GT_("OpenSSL reported: %s\n"), errstr);
+    }
+}
+
+/* override ERR_print_errors_fp to our own implementation */
+#undef ERR_print_errors_fp
+#define ERR_print_errors_fp(stream) report_SSL_errors((stream))
+
+static SSL_CTX *_ctx[FD_SETSIZE];
+static SSL *_ssl_context[FD_SETSIZE];
+
+static SSL     *SSLGetContext( int );
+#endif /* SSL_ENABLE */
+
+int SockWrite(int sock, const char *buf, int len)
 {
     int n, wrlen = 0;
+#ifdef SSL_ENABLE
+    SSL *ssl;
+#endif
 
     while (len)
     {
-        n = write(sock, buf, 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;
@@ -208,9 +426,20 @@ int SockRead(int sock, char *buf, int len)
 {
     char *newline, *bp = buf;
     int n;
+#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:
@@ -218,17 +447,80 @@ int SockRead(int sock, char *buf, int len)
         * (2) to return the true length of data read, even if the
         *     data coming in has embedded NULS.
         */
-       if ((n = recv(sock, bp, len, MSG_PEEK)) <= 0)
-           return(-1);
-       if ((newline = memchr(bp, '\n', n)) != NULL)
-           n = newline - bp + 1;
-       if ((n = read(sock, bp, n)) == -1)
-           return(-1);
+#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 lose 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);
+               }
+               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 != 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 = (char *)memchr(bp, '\n', n)) != NULL)
+                       n = newline - bp + 1;
+               /* Matthias Andree: SSL_read can return 0, in that case
+                * we must call 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);
+           if ((newline = (char *)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';
+
     return bp - buf;
 }
 
@@ -237,34 +529,563 @@ int SockPeek(int sock)
 {
     int n;
     char ch;
+#ifdef SSL_ENABLE
+    SSL *ssl;
+#endif
 
-    if ((n = recv(sock, &ch, 1, MSG_PEEK)) == -1)
-       return -1;
-    else
-       return(ch);
+#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 != 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;
+static int _firstrun;
+static int _prev_err;
+static int _verify_ok;
+
+SSL *SSLGetContext( int sock )
+{
+       if( sock < 0 || (unsigned)sock > FD_SETSIZE )
+               return NULL;
+       if( _ctx[sock] == NULL )
+               return NULL;
+       return _ssl_context[sock];
+}
+
+/* ok_return (preverify_ok) is 1 if this stage of certificate verification
+   passed, or 0 if it failed. This callback lets us display informative
+   errors, and perform additional validation (e.g. CN matches) */
+static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict )
+{
+#define SSLverbose (((outlevel) >= O_DEBUG) || ((outlevel) >= O_VERBOSE && (depth) == 0)) 
+       char buf[257];
+       X509 *x509_cert;
+       int err, depth, i;
+       unsigned char digest[EVP_MAX_MD_SIZE];
+       char text[EVP_MAX_MD_SIZE * 3 + 1], *tp, *te;
+       const EVP_MD *digest_tp;
+       unsigned int dsz, esz;
+       X509_NAME *subj, *issuer;
+       char *tt;
+
+       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 (outlevel >= O_VERBOSE) {
+               if (depth == 0 && SSLverbose)
+                       report(stdout, GT_("Server certificate:\n"));
+               else {
+                       if (_firstrun) {
+                               _firstrun = 0;
+                               if (SSLverbose)
+                                       report(stdout, GT_("Certificate chain, from root to peer, starting at depth %d:\n"), depth);
+                       } else {
+                               if (SSLverbose)
+                                       report(stdout, GT_("Certificate at depth %d:\n"), depth);
+                       }
+               }
+
+               if (SSLverbose) {
+                       if ((i = X509_NAME_get_text_by_NID(issuer, NID_organizationName, buf, sizeof(buf))) != -1) {
+                               report(stdout, GT_("Issuer Organization: %s\n"), (tt = sdump(buf, i)));
+                               xfree(tt);
+                               if ((size_t)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"), (tt = sdump(buf, i)));
+                               xfree(tt);
+                               if ((size_t)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 (SSLverbose) {
+                       report(stdout, GT_("Subject CommonName: %s\n"), (tt = sdump(buf, i)));
+                       xfree(tt);
+               }
+               if ((size_t)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 ((size_t)i > strlen(buf)) {
+                       /* Name contains embedded NUL characters, so we complain. This is likely
+                        * a certificate spoofing attack. */
+                       report(stderr, GT_("Bad certificate: Subject CommonName contains NUL, aborting!\n"));
+                       return 0;
+               }
+       }
+
+       if (depth == 0) { /* peer certificate */
+               if (!_depth0ck) {
+                       _depth0ck = 1;
+               }
+
+               if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) {
+                       if (_ssl_server_cname != NULL) {
+                               char *p1 = buf;
+                               char *p2 = _ssl_server_cname;
+                               int matched = 0;
+                               STACK_OF(GENERAL_NAME) *gens;
+
+                               /* RFC 2595 section 2.4: find a matching name
+                                * first find a match among alternative names */
+                               gens = (STACK_OF(GENERAL_NAME) *)X509_get_ext_d2i(x509_cert, NID_subject_alt_name, NULL, NULL);
+                               if (gens) {
+                                       int j, r;
+                                       for (j = 0, r = sk_GENERAL_NAME_num(gens); j < r; ++j) {
+                                               const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, j);
+                                               if (gn->type == GEN_DNS) {
+                                                       char *pp1 = (char *)gn->d.ia5->data;
+                                                       char *pp2 = _ssl_server_cname;
+                                                       if (outlevel >= O_VERBOSE) {
+                                                               report(stdout, GT_("Subject Alternative Name: %s\n"), (tt = sdump(pp1, (size_t)gn->d.ia5->length)));
+                                                               xfree(tt);
+                                                       }
+                                                       /* Name contains embedded NUL characters, so we complain. This
+                                                        * is likely a certificate spoofing attack. */
+                                                       if ((size_t)gn->d.ia5->length != strlen(pp1)) {
+                                                               report(stderr, GT_("Bad certificate: Subject Alternative Name contains NUL, aborting!\n"));
+                                                               sk_GENERAL_NAME_free(gens);
+                                                               return 0;
+                                                       }
+                                                       if (name_match(pp1, pp2)) {
+                                                           matched = 1;
+                                                       }
+                                               }
+                                       }
+                                       GENERAL_NAMES_free(gens);
+                               }
+                               if (name_match(p1, p2)) {
+                                       matched = 1;
+                               }
+                               if (!matched) {
+                                       if (strict || SSLverbose) {
+                                               report(stderr,
+                                                               GT_("Server CommonName mismatch: %s != %s\n"),
+                                                               (tt = sdump(buf, i)), _ssl_server_cname );
+                                               xfree(tt);
+                                       }
+                                       ok_return = 0;
+                               }
+                       } else if (ok_return) {
+                               report(stderr, GT_("Server name not set, could not verify certificate!\n"));
+                               if (strict) 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 == 1) {
+                       unsigned dp;
+
+                       _check_fp = -1;
+                       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 (dp = 0; dp < dsz; dp++) {
+                               esz = snprintf(tp, te - tp, dp > 0 ? ":%02X" : "%02X", digest[dp]);
+                               if (esz >= (size_t)(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 (strcasecmp(text, _check_digest) == 0) {
+                                   if (outlevel > O_NORMAL)
+                                       report(stdout, GT_("%s fingerprints match.\n"), _server_label);
+                               } else {
+                                   report(stderr, GT_("%s fingerprints do not match!\n"), _server_label);
+                                   return (0);
+                               }
+                       } /* if (_check_digest != NULL) */
+               } /* if (_check_fp) */
+       } /* if (depth == 0 && !_depth0ck) */
+
+       if (err != X509_V_OK && err != _prev_err && !(_check_fp != 0 && _check_digest && !strict)) {
+               char *tmp;
+               int did_rep_err = 0;
+               _prev_err = err;
+
+                report(stderr, GT_("Server certificate verification error: %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) {
+               /* actually we do not want to lump these together, but
+                * since OpenSSL flipped the meaning of these error
+                * codes in the past, and they do hardly make a
+                * practical difference because servers need not provide
+                * the root signing certificate, we don't bother telling
+                * users the difference:
+                */
+               case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
+               case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
+                       X509_NAME_oneline(issuer, buf, sizeof(buf));
+                       buf[sizeof(buf) - 1] = '\0';
+                       report(stderr, GT_("Broken certification chain at: %s\n"), (tmp = sdump(buf, strlen(buf))));
+                       xfree(tmp);
+                       report(stderr, GT_(     "This could mean that the server did not provide the intermediate CA's certificate(s), "
+                                               "which is nothing fetchmail could do anything about.  For details, "
+                                               "please see the README.SSL-SERVER document that ships with fetchmail.\n"));
+                       did_rep_err = 1;
+                       /* FALLTHROUGH */
+               case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
+               case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
+                       if (!did_rep_err) {
+                           X509_NAME_oneline(issuer, buf, sizeof(buf));
+                           buf[sizeof(buf) - 1] = '\0';
+                           report(stderr, GT_("Missing trust anchor certificate: %s\n"), (tmp = sdump(buf, strlen(buf))));
+                           xfree(tmp);
+                       }
+                       report(stderr, GT_(     "This could mean that the root CA's signing certificate is not in the "
+                                               "trusted CA certificate location, or that c_rehash needs to be run "
+                                               "on the certificate directory. For details, please "
+                                               "see the documentation of --sslcertpath and --sslcertfile in the manual page.\n"));
+                       break;
+               default:
+                       break;
+               }
+       }
+       /*
+        * If not in strict checking mode (--sslcertck), override this
+        * and pretend that verification had succeeded.
+        */
+       _verify_ok &= ok_return;
+       if (!strict)
+               ok_return = 1;
+       return (ok_return);
+}
+
+static int SSL_nock_verify_callback( int ok_return, X509_STORE_CTX *ctx )
+{
+       return SSL_verify_callback(ok_return, ctx, 0);
+}
+
+static int SSL_ck_verify_callback( int ok_return, X509_STORE_CTX *ctx )
+{
+       return SSL_verify_callback(ok_return, ctx, 1);
+}
+
+
+/* get commonName from certificate set in file.
+ * commonName is stored in buffer namebuffer, limited with namebufferlen
+ */
+static const char *SSLCertGetCN(const char *mycert,
+                                char *namebuffer, size_t namebufferlen)
+{
+       const char *ret       = NULL;
+       BIO        *certBio   = NULL;
+       X509       *x509_cert = NULL;
+       X509_NAME  *certname  = NULL;
+
+       if (namebuffer && namebufferlen > 0) {
+               namebuffer[0] = 0x00;
+               certBio = BIO_new_file(mycert,"r");
+               if (certBio) {
+                       x509_cert = PEM_read_bio_X509(certBio,NULL,NULL,NULL);
+                       BIO_free(certBio);
+               }
+               if (x509_cert) {
+                       certname = X509_get_subject_name(x509_cert);
+                       if (certname &&
+                           X509_NAME_get_text_by_NID(certname, NID_commonName,
+                                                     namebuffer, namebufferlen) > 0)
+                               ret = namebuffer;
+                       X509_free(x509_cert);
+               }
+       }
+       return ret;
+}
+
+/* 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, const char *myproto, int certck,
+    char *cacertfile, char *certpath,
+    char *fingerprint, char *servercname, char *label, char **remotename)
+{
+        struct stat randstat;
+        int i;
+       long sslopts = SSL_OP_ALL;
+
+       SSL_load_error_strings();
+       SSL_library_init();
+       OpenSSL_add_all_algorithms(); /* see Debian Bug#576430 and manpage */
+
+        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);
+          }
+        }
+
+       if( sock < 0 || (unsigned)sock > FD_SETSIZE ) {
+               report(stderr, GT_("File descriptor out of range for SSL") );
+               return( -1 );
+       }
+
+       /* Make sure a connection referring to an older context is not left */
+       _ssl_context[sock] = NULL;
+       if(myproto) {
+               if(!strcasecmp("ssl2",myproto)) {
+#if HAVE_DECL_SSLV2_CLIENT_METHOD + 0 > 0
+                       _ctx[sock] = SSL_CTX_new(SSLv2_client_method());
+#else
+                       report(stderr, GT_("Your operating system does not support SSLv2.\n"));
+                       return -1;
+#endif
+               } else if(!strcasecmp("ssl3",myproto)) {
+                       _ctx[sock] = SSL_CTX_new(SSLv3_client_method());
+               } else if(!strcasecmp("tls1",myproto)) {
+                       _ctx[sock] = SSL_CTX_new(TLSv1_client_method());
+               } else if (!strcasecmp("ssl23",myproto)) {
+                       myproto = NULL;
+               } else {
+                       report(stderr,GT_("Invalid SSL protocol '%s' specified, using default (SSLv23).\n"), myproto);
+                       myproto = NULL;
+               }
+       }
+       if(!myproto) {
+               _ctx[sock] = SSL_CTX_new(SSLv23_client_method());
+       }
+       if(_ctx[sock] == NULL) {
+               ERR_print_errors_fp(stderr);
+               return(-1);
+       }
+
+       {
+           char *tmp = getenv("FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE");
+           if (tmp == NULL || *tmp == '\0' || strspn(tmp, " \t") == strlen(tmp))
+               sslopts &= ~ SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
+       }
+
+       SSL_CTX_set_options(_ctx[sock], sslopts);
+
+       if (certck) {
+               SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_ck_verify_callback);
+       } 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[sock], SSL_VERIFY_PEER, SSL_nock_verify_callback);
+       }
+
+       /* Check which trusted X.509 CA certificate store(s) to load */
+       {
+               char *tmp;
+               int want_default_cacerts = 0;
+
+               /* Load user locations if any is given */
+               if (certpath || cacertfile)
+                       SSL_CTX_load_verify_locations(_ctx[sock],
+                                               cacertfile, certpath);
+               else
+                       want_default_cacerts = 1;
+
+               tmp = getenv("FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS");
+               if (want_default_cacerts || (tmp && tmp[0])) {
+                       SSL_CTX_set_default_verify_paths(_ctx[sock]);
+               }
+       }
+       
+       _ssl_context[sock] = SSL_new(_ctx[sock]);
+       
+       if(_ssl_context[sock] == NULL) {
+               ERR_print_errors_fp(stderr);
+               SSL_CTX_free(_ctx[sock]);
+               _ctx[sock] = NULL;
+               return(-1);
+       }
+       
+       /* This static is for the verify callback */
+       _ssl_server_cname = servercname;
+       _server_label = label;
+       _check_fp = 1;
+       _check_digest = fingerprint;
+       _depth0ck = 0;
+       _firstrun = 1;
+       _verify_ok = 1;
+       _prev_err = -1;
+
+       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.
+        */
+               char buffer[256];
+               
+               if( !mykey )
+                       mykey = mycert;
+               if( !mycert )
+                       mycert = mykey;
+
+               if ((!*remotename || !**remotename) && SSLCertGetCN(mycert, buffer, sizeof(buffer))) {
+                       free(*remotename);
+                       *remotename = xstrdup(buffer);
+               }
+               SSL_use_certificate_file(_ssl_context[sock], mycert, SSL_FILETYPE_PEM);
+               SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM);
+       }
+
+       if (SSL_set_fd(_ssl_context[sock], sock) == 0 
+           || SSL_connect(_ssl_context[sock]) < 1) {
+               ERR_print_errors_fp(stderr);
+               SSL_free( _ssl_context[sock] );
+               _ssl_context[sock] = NULL;
+               SSL_CTX_free(_ctx[sock]);
+               _ctx[sock] = NULL;
+               return(-1);
+       }
+
+       /* Paranoia: was the callback not called as we expected? */
+       if (!_depth0ck) {
+               report(stderr, GT_("Certificate/fingerprint verification was somehow skipped!\n"));
+
+               if (fingerprint != NULL || certck) {
+                       if( NULL != SSLGetContext( sock ) ) {
+                               /* Clean up the SSL stack */
+                               SSL_shutdown( _ssl_context[sock] );
+                               SSL_free( _ssl_context[sock] );
+                               _ssl_context[sock] = NULL;
+                               SSL_CTX_free(_ctx[sock]);
+                               _ctx[sock] = NULL;
+                       }
+                       return(-1);
+               }
+       }
+
+       if (!certck && !fingerprint &&
+               (SSL_get_verify_result(_ssl_context[sock]) != X509_V_OK || !_verify_ok)) {
+               report(stderr, GT_("Warning: the connection is insecure, continuing anyways. (Better use --sslcertck!)\n"));
+       }
+
+       return(0);
 }
+#endif
 
 int SockClose(int sock)
-/* close a socket (someday we may do other cleanup here) */
+/* close a socket gracefully */
 {
-    return(close(sock));
+#ifdef SSL_ENABLE
+    if( NULL != SSLGetContext( sock ) ) {
+        /* Clean up the SSL stack */
+        SSL_shutdown( _ssl_context[sock] );
+        SSL_free( _ssl_context[sock] );
+        _ssl_context[sock] = NULL;
+       SSL_CTX_free(_ctx[sock]);
+       _ctx[sock] = NULL;
+    }
+#endif
+
+    /* if there's an error closing at this point, not much we can do */
+    return(fm_close(sock));    /* this is guarded */
 }
 
-#ifdef MAIN
+#ifdef __CYGWIN__
 /*
- * 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. 
+ * Workaround Microsoft Winsock recv/WSARecv(..., MSG_PEEK) bug.
+ * See http://sources.redhat.com/ml/cygwin/2001-08/msg00628.html
+ * for more details.
  */
-main()
+static ssize_t cygwin_read(int sock, void *buf, size_t count)
 {
-    int                sock = SockOpen("localhost", 19, NULL);
-    char       buf[80];
+    char *bp = (char *)buf;
+    size_t n = 0;
 
-    while (SockRead(sock, buf, sizeof(buf)-1))
-       SockWrite(1, buf, strlen(buf));
-    SockClose(sock);
-}
-#endif /* MAIN */
+    if ((n = read(sock, bp, count)) == (size_t)-1)
+       return(-1);
 
-/* socket.c ends here */
+    if (n != count) {
+       size_t n2 = 0;
+       if (outlevel >= O_VERBOSE)
+           report(stdout, GT_("Cygwin socket read retry\n"));
+       n2 = read(sock, bp + n, count - n);
+       if (n2 == (size_t)-1 || n + n2 != count) {
+           report(stderr, GT_("Cygwin socket read retry failed!\n"));
+           return(-1);
+       }
+    }
+
+    return count;
+}
+#endif /* __CYGWIN__ */