avoid buffer overflow
[openssl.git] / apps / s_server.c
index 2fa35f4d101fb60e6600f4daf7f9a389c17050b4..cd1aa17b26ac5b90d8e95ec9cdc6211dcb397039 100644 (file)
@@ -62,6 +62,7 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <openssl/e_os2.h>
 #ifdef OPENSSL_NO_STDIO
 #define APPS_WIN16
 #endif
@@ -104,6 +105,8 @@ static void close_accept_socket(void );
 static void sv_usage(void);
 static int init_ssl_connection(SSL *s);
 static void print_stats(BIO *bp,SSL_CTX *ctx);
+static int generate_session_id(const SSL *ssl, unsigned char *id,
+                               unsigned int *id_len);
 #ifndef OPENSSL_NO_DH
 static DH *load_dh_param(char *dhfile);
 static DH *get_dh512(void);
@@ -178,6 +181,7 @@ static int s_quiet=0;
 
 static int hack=0;
 static char *engine_id=NULL;
+static const char *session_id_prefix=NULL;
 
 #ifdef MONOLITH
 static void s_server_init(void)
@@ -246,7 +250,10 @@ static void sv_usage(void)
        BIO_printf(bio_err," -bugs         - Turn on SSL bug compatibility\n");
        BIO_printf(bio_err," -www          - Respond to a 'GET /' with a status page\n");
        BIO_printf(bio_err," -WWW          - Respond to a 'GET /<path> HTTP/1.0' with file ./<path>\n");
+       BIO_printf(bio_err," -HTTP         - Respond to a 'GET /<path> HTTP/1.0' with file ./<path>\n");
+        BIO_printf(bio_err,"                 with the assumption it contains a complete HTTP response.\n");
        BIO_printf(bio_err," -engine id    - Initialise and use the specified engine\n");
+       BIO_printf(bio_err," -id_prefix arg - Generate SSL/TLS session IDs prefixed by 'arg'\n");
        BIO_printf(bio_err," -rand file%cfile%c...\n", LIST_SEPARATOR_CHAR, LIST_SEPARATOR_CHAR);
        }
 
@@ -554,6 +561,8 @@ int MAIN(int argc, char *argv[])
                        { www=1; }
                else if (strcmp(*argv,"-WWW") == 0)
                        { www=2; }
+               else if (strcmp(*argv,"-HTTP") == 0)
+                       { www=3; }
                else if (strcmp(*argv,"-no_ssl2") == 0)
                        { off|=SSL_OP_NO_SSLv2; }
                else if (strcmp(*argv,"-no_ssl3") == 0)
@@ -572,6 +581,11 @@ int MAIN(int argc, char *argv[])
                else if (strcmp(*argv,"-tls1") == 0)
                        { meth=TLSv1_server_method(); }
 #endif
+               else if (strcmp(*argv, "-id_prefix") == 0)
+                       {
+                       if (--argc < 1) goto bad;
+                       session_id_prefix = *(++argv);
+                       }
                else if (strcmp(*argv,"-engine") == 0)
                        {
                        if (--argc < 1) goto bad;
@@ -662,7 +676,22 @@ bad:
                ERR_print_errors(bio_err);
                goto end;
                }
-
+       if (session_id_prefix)
+               {
+               if(strlen(session_id_prefix) >= 32)
+                       BIO_printf(bio_err,
+"warning: id_prefix is too long, only one new session will be possible\n");
+               else if(strlen(session_id_prefix) >= 16)
+                       BIO_printf(bio_err,
+"warning: id_prefix is too long if you use SSLv2\n");
+               if(!SSL_CTX_set_generate_session_id(ctx, generate_session_id))
+                       {
+                       BIO_printf(bio_err,"error setting 'id_prefix'\n");
+                       ERR_print_errors(bio_err);
+                       goto end;
+                       }
+               BIO_printf(bio_err,"id_prefix '%s' set.\n", session_id_prefix);
+               }
        SSL_CTX_set_quiet_shutdown(ctx,1);
        if (bugs) SSL_CTX_set_options(ctx,SSL_OP_ALL);
        if (hack) SSL_CTX_set_options(ctx,SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG);
@@ -1389,7 +1418,8 @@ static int www_body(char *hostname, int s, unsigned char *context)
                        BIO_puts(io,"</BODY></HTML>\r\n\r\n");
                        break;
                        }
-               else if ((www == 2) && (strncmp("GET /",buf,5) == 0))
+               else if ((www == 2 || www == 3)
+                         && (strncmp("GET /",buf,5) == 0))
                        {
                        BIO *file;
                        char *p,*e;
@@ -1397,15 +1427,29 @@ static int www_body(char *hostname, int s, unsigned char *context)
 
                        /* skip the '/' */
                        p= &(buf[5]);
-                       dot=0;
+
+                       dot = 1;
                        for (e=p; *e != '\0'; e++)
                                {
-                               if (e[0] == ' ') break;
-                               if (    (e[0] == '.') &&
-                                       (strncmp(&(e[-1]),"/../",4) == 0))
-                                       dot=1;
+                               if (e[0] == ' ')
+                                       break;
+
+                               switch (dot)
+                                       {
+                               case 1:
+                                       dot = (e[0] == '.') ? 2 : 0;
+                                       break;
+                               case 2:
+                                       dot = (e[0] == '.') ? 3 : 0;
+                                       break;
+                               case 3:
+                                       dot = (e[0] == '/') ? -1 : 0;
+                                       break;
+                                       }
+                               if (dot == 0)
+                                       dot = (e[0] == '/') ? 1 : 0;
                                }
-                       
+                       dot = (dot == 3) || (dot == -1); /* filename contains ".." component */
 
                        if (*e == '\0')
                                {
@@ -1429,9 +1473,11 @@ static int www_body(char *hostname, int s, unsigned char *context)
                                break;
                                }
 
+#if 0
                        /* append if a directory lookup */
                        if (e[-1] == '/')
                                strcat(p,"index.html");
+#endif
 
                        /* if a directory, do the index thang */
                        if (stat(p,&st_buf) < 0)
@@ -1443,7 +1489,13 @@ static int www_body(char *hostname, int s, unsigned char *context)
                                }
                        if (S_ISDIR(st_buf.st_mode))
                                {
+#if 0 /* must check buffer size */
                                strcat(p,"/index.html");
+#else
+                               BIO_puts(io,text);
+                               BIO_printf(io,"'%s' is a directory\r\n",p);
+                               break;
+#endif
                                }
 
                        if ((file=BIO_new_file(p,"r")) == NULL)
@@ -1457,13 +1509,16 @@ static int www_body(char *hostname, int s, unsigned char *context)
                        if (!s_quiet)
                                BIO_printf(bio_err,"FILE:%s\n",p);
 
-                       i=strlen(p);
-                       if (    ((i > 5) && (strcmp(&(p[i-5]),".html") == 0)) ||
-                               ((i > 4) && (strcmp(&(p[i-4]),".php") == 0)) ||
-                               ((i > 4) && (strcmp(&(p[i-4]),".htm") == 0)))
-                               BIO_puts(io,"HTTP/1.0 200 ok\r\nContent-type: text/html\r\n\r\n");
-                       else
-                               BIO_puts(io,"HTTP/1.0 200 ok\r\nContent-type: text/plain\r\n\r\n");
+                        if (www == 2)
+                                {
+                                i=strlen(p);
+                                if (   ((i > 5) && (strcmp(&(p[i-5]),".html") == 0)) ||
+                                        ((i > 4) && (strcmp(&(p[i-4]),".php") == 0)) ||
+                                        ((i > 4) && (strcmp(&(p[i-4]),".htm") == 0)))
+                                        BIO_puts(io,"HTTP/1.0 200 ok\r\nContent-type: text/html\r\n\r\n");
+                                else
+                                        BIO_puts(io,"HTTP/1.0 200 ok\r\nContent-type: text/plain\r\n\r\n");
+                                }
                        /* send the file */
                        total_bytes=0;
                        for (;;)
@@ -1563,3 +1618,26 @@ static RSA MS_CALLBACK *tmp_rsa_cb(SSL *s, int is_export, int keylength)
        return(rsa_tmp);
        }
 #endif
+
+#define MAX_SESSION_ID_ATTEMPTS 10
+static int generate_session_id(const SSL *ssl, unsigned char *id,
+                               unsigned int *id_len)
+       {
+       unsigned int count = 0;
+       do      {
+               RAND_pseudo_bytes(id, *id_len);
+               /* Prefix the session_id with the required prefix. NB: If our
+                * prefix is too long, clip it - but there will be worse effects
+                * anyway, eg. the server could only possibly create 1 session
+                * ID (ie. the prefix!) so all future session negotiations will
+                * fail due to conflicts. */
+               memcpy(id, session_id_prefix,
+                       (strlen(session_id_prefix) < *id_len) ?
+                       strlen(session_id_prefix) : *id_len);
+               }
+       while(SSL_has_matching_session_id(ssl, id, *id_len) &&
+               (++count < MAX_SESSION_ID_ATTEMPTS));
+       if(count >= MAX_SESSION_ID_ATTEMPTS)
+               return 0;
+       return 1;
+       }