diff -ruNH stunnel-4.06_orig/src/client.c stunnel-4.06/src/client.c
--- stunnel-4.06_orig/src/client.c	2004-12-26 00:42:08.000000000 +0100
+++ stunnel-4.06/src/client.c	2004-12-29 16:25:48.125017255 +0100
@@ -111,6 +111,7 @@
 #endif
     c->remote_fd.fd=-1;
     c->ssl=NULL;
+    c->header_length = 0;
     cleanup(c, do_client(c));
 #ifdef USE_FORK
     if(!c->opt->option.remote) /* 'exec' specified */
@@ -194,6 +195,13 @@
                 c->accepting_address);
             return -1;
         }
+
+        /* create X-Forwarded-For header if necessary */
+        if (c->opt->option.xforwardedfor) {
+         sprintf(c->header_buff, "X-Forwarded-For: %s\r\n", c->accepting_address);
+         c->header_length = strlen(c->header_buff);
+         s_log(LOG_DEBUG, "X-Forwarded-For header is '%s' [%d]", c->header_buff, c->header_length);
+       }
         s_log(LOG_NOTICE, "%s connected from %s",
             c->opt->servname, c->accepting_address);
     }
@@ -361,6 +369,7 @@
         /* 0=not closing SSL, 1=initiate SSL_shutdown,
          * 2=retry SSL_shutdown, 3=SSL_shutdown done */
     int watchdog=0; /* a counter to detect an infinite loop */
+    int header_sent = 0;
 
     c->sock_ptr=c->ssl_ptr=0;
     sock_rd=sock_wr=ssl_rd=ssl_wr=1;
@@ -456,6 +465,26 @@
                 s_log(LOG_DEBUG, "No data written to the socket: retrying");
                 break;
             default:
+
+                /* insert X-Forwarded-For header if desired and not yet included */
+                if (c->opt->option.xforwardedfor && ! header_sent) {
+                  char *eol = memchr(c->ssl_buff, '\n', num);
+ 
+                  if (eol) {
+ 
+                    /* make room for X-Forwarded-For header */
+                    memmove(eol+1+c->header_length, eol+1, (eol - c->ssl_buff) + 1);
+
+                    /* insert X-Forwarded-For header */
+                    memcpy(eol + 1, c->header_buff, c->header_length);
+                    c->ssl_ptr = num += c->header_length+1;
+                    s_log(LOG_DEBUG, "re-written buffer is '%.*s' [%d]\n\n", num, c->ssl_buff, num);
+                  }else{
+                    s_log(LOG_DEBUG, "can't add X-Forwarded-For header\n");
+                  }
+                  header_sent = 1;
+                }
+
                 memmove(c->ssl_buff, c->ssl_buff+num, c->ssl_ptr-num);
                 if(c->ssl_ptr==BUFFSIZE)
                     check_SSL_pending=1;
diff -ruNH stunnel-4.06_orig/src/options.c stunnel-4.06/src/options.c
--- stunnel-4.06_orig/src/options.c	2004-12-25 23:46:32.000000000 +0100
+++ stunnel-4.06/src/options.c	2004-12-29 13:20:23.000000000 +0100
@@ -978,6 +978,29 @@
     }
 #endif
 
+     /* xforwardedfor */
+     switch(cmd) {
+     case CMD_INIT:
+         section->option.xforwardedfor=0;
+         break;
+     case CMD_EXEC:
+         if(strcasecmp(opt, "xforwardedfor"))
+             break;
+         if(!strcasecmp(arg, "yes"))
+             section->option.xforwardedfor=1;
+         else if(!strcasecmp(arg, "no"))
+             section->option.xforwardedfor=0;
+         else
+             return "argument should be either 'yes' or 'no'";
+         return NULL; /* OK */
+     case CMD_DEFAULT:
+         break;
+     case CMD_HELP:
+         log_raw("%-15s = yes|no send X-Forwarded-For HTTP headers",
+             "xforwardedfor");
+         break;
+     }
+ 
     if(cmd==CMD_EXEC)
         return option_not_found;
     return NULL; /* OK */
diff -ruNH stunnel-4.06_orig/src/prototypes.h stunnel-4.06/src/prototypes.h
--- stunnel-4.06_orig/src/prototypes.h	2004-12-25 22:24:09.000000000 +0100
+++ stunnel-4.06/src/prototypes.h	2004-12-29 11:12:36.000000000 +0100
@@ -195,6 +195,7 @@
         unsigned int delayed_lookup:1;
         unsigned int accept:1;
         unsigned int remote:1;
+        unsigned int xforwardedfor:1;
 #ifndef USE_WIN32
         unsigned int program:1;
         unsigned int pty:1;
@@ -252,6 +253,8 @@
     FD *sock_rfd, *sock_wfd; /* Read and write socket descriptors */
     FD *ssl_rfd, *ssl_wfd; /* Read and write SSL descriptors */
     int sock_bytes, ssl_bytes; /* Bytes written to socket and ssl */
+    char header_buff[48]; /* Text of X-Forwarded-For header */
+    int header_length; /* Length of X-Forwarded-For header */
 } CLI;
 
 extern int max_clients;