X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fsrc%2Fparse.c;h=9bc76c3c6a4058ef1c4a15fbbee8841d63df7d99;hp=d3f382b9648468e9123df17ff79e926aff587f21;hb=dce58c04af4439fec7269f83886e22b503756a8f;hpb=bfe645c1570343d3adca657ab67998e122ca8792

diff --git a/src/src/parse.c b/src/src/parse.c
index d3f382b96..9bc76c3c6 100644
--- a/src/src/parse.c
+++ b/src/src/parse.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2015 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions for parsing addresses */
@@ -23,7 +23,7 @@ redundant apparatus. */
 
 address_item *deliver_make_addr(uschar *address, BOOL copy)
 {
-address_item *addr = store_get(sizeof(address_item));
+address_item *addr = store_get(sizeof(address_item), FALSE);
 addr->next = NULL;
 addr->parent = NULL;
 addr->address = address;
@@ -187,7 +187,7 @@ The start of the last potential comment position is remembered to
 make it possible to ignore comments at the end of compound items.
 
 Argument: current character pointer
-Regurns:  new character pointer
+Returns:  new character pointer
 */
 
 static uschar *
@@ -197,10 +197,10 @@ last_comment_position = s;
 while (*s)
   {
   int c, level;
-  while (isspace(*s)) s++;
-  if (*s != '(') break;
+
+  if (Uskip_whitespace(&s) != '(') break;
   level = 1;
-  while((c = *(++s)) != 0)
+  while((c = *(++s)))
     {
     if (c == '(') level++;
     else if (c == ')') { if (--level <= 0) { s++; break; } }
@@ -421,10 +421,10 @@ for (;;)
   if (*s == '\"')
     {
     *t++ = '\"';
-    while ((c = *(++s)) != 0 && c != '\"')
+    while ((c = *++s) && c != '\"')
       {
       *t++ = c;
-      if (c == '\\' && s[1] != 0) *t++ = *(++s);
+      if (c == '\\' && s[1]) *t++ = *++s;
       }
     if (c == '\"')
       {
@@ -443,7 +443,7 @@ for (;;)
   else while (!mac_iscntrl_or_special(*s) || *s == '\\')
     {
     c = *t++ = *s++;
-    if (c == '\\' && *s != 0) *t++ = *s++;
+    if (c == '\\' && *s) *t++ = *s++;
     }
 
   /* Terminate the word and skip subsequent comment */
@@ -618,10 +618,10 @@ uschar *
 parse_extract_address(uschar *mailbox, uschar **errorptr, int *start, int *end,
   int *domain, BOOL allow_null)
 {
-uschar *yield = store_get(Ustrlen(mailbox) + 1);
+uschar *yield = store_get(Ustrlen(mailbox) + 1, is_tainted(mailbox));
 uschar *startptr, *endptr;
-uschar *s = (uschar *)mailbox;
-uschar *t = (uschar *)yield;
+uschar *s = US mailbox;
+uschar *t = US yield;
 
 *domain = 0;
 
@@ -638,7 +638,7 @@ RESTART:   /* Come back here after passing a group name */
 s = skip_comment(s);
 startptr = s;                                 /* In case addr-spec */
 s = read_local_part(s, t, errorptr, TRUE);    /* Dot separated words */
-if (*errorptr != NULL) goto PARSE_FAILED;
+if (*errorptr) goto PARSE_FAILED;
 
 /* If the terminator is neither < nor @ then the format of the address
 must either be a bare local-part (we are now at the end), or a phrase
@@ -658,10 +658,10 @@ if (*s != '@' && *s != '<')
   end of string will produce a null local_part and therefore fail. We don't
   need to keep updating t, as the phrase isn't to be kept. */
 
-  while (*s != '<' && (!parse_allow_group || *s != ':'))
+  while (*s != '<' && (!f.parse_allow_group || *s != ':'))
     {
     s = read_local_part(s, t, errorptr, FALSE);
-    if (*errorptr != NULL)
+    if (*errorptr)
       {
       *errorptr = string_sprintf("%s (expected word or \"<\")", *errorptr);
       goto PARSE_FAILED;
@@ -670,8 +670,8 @@ if (*s != '@' && *s != '<')
 
   if (*s == ':')
     {
-    parse_found_group = TRUE;
-    parse_allow_group = FALSE;
+    f.parse_found_group = TRUE;
+    f.parse_allow_group = FALSE;
     s++;
     goto RESTART;
     }
@@ -686,8 +686,8 @@ processing it. Note that this is "if" rather than "else if" because it's also
 used after reading a preceding phrase.
 
 There are a lot of broken sendmails out there that put additional pairs of <>
-round <route-addr>s. If strip_excess_angle_brackets is set, allow any number of
-them, as long as they match. */
+round <route-addr>s.  If strip_excess_angle_brackets is set, allow a limited
+number of them, as long as they match. */
 
 if (*s == '<')
   {
@@ -696,8 +696,11 @@ if (*s == '<')
   int bracket_count = 1;
 
   s++;
-  if (strip_excess_angle_brackets)
-    while (*s == '<') { bracket_count++; s++; }
+  if (strip_excess_angle_brackets) while (*s == '<')
+   {
+   if(bracket_count++ > 5) FAILED(US"angle-brackets nested too deep");
+   s++;
+   }
 
   t = yield;
   startptr = s;
@@ -711,7 +714,7 @@ if (*s == '<')
   if (*s == '@')
     {
     s = read_route(s, t, errorptr);
-    if (*errorptr != NULL) goto PARSE_FAILED;
+    if (*errorptr) goto PARSE_FAILED;
     *t = 0;                  /* Ensure route is ignored - probably overkill */
     source_routed = TRUE;
     }
@@ -729,7 +732,7 @@ if (*s == '<')
   else
     {
     s = read_addr_spec(s, t, '>', errorptr, &domainptr);
-    if (*errorptr != NULL) goto PARSE_FAILED;
+    if (*errorptr) goto PARSE_FAILED;
     *domain = domainptr - yield;
     if (source_routed && *domain == 0)
       FAILED(US"domain missing in source-routed address");
@@ -739,9 +742,10 @@ if (*s == '<')
   if (*errorptr != NULL) goto PARSE_FAILED;
   while (bracket_count-- > 0) if (*s++ != '>')
     {
-    *errorptr = (s[-1] == 0)? US"'>' missing at end of address" :
-      string_sprintf("malformed address: %.32s may not follow %.*s",
-        s-1, s - (uschar *)mailbox - 1, mailbox);
+    *errorptr = s[-1] == 0
+      ? US"'>' missing at end of address"
+      : string_sprintf("malformed address: %.32s may not follow %.*s",
+	  s-1, (int)(s - US mailbox - 1), mailbox);
     goto PARSE_FAILED;
     }
 
@@ -786,21 +790,21 @@ move it back past white space if necessary. */
 PARSE_SUCCEEDED:
 if (*s != 0)
   {
-  if (parse_found_group && *s == ';')
+  if (f.parse_found_group && *s == ';')
     {
-    parse_found_group = FALSE;
-    parse_allow_group = TRUE;
+    f.parse_found_group = FALSE;
+    f.parse_allow_group = TRUE;
     }
   else
     {
     *errorptr = string_sprintf("malformed address: %.32s may not follow %.*s",
-      s, s - (uschar *)mailbox, mailbox);
+      s, (int)(s - US mailbox), mailbox);
     goto PARSE_FAILED;
     }
   }
-*start = startptr - (uschar *)mailbox;      /* Return offsets */
+*start = startptr - US mailbox;      /* Return offsets */
 while (isspace(endptr[-1])) endptr--;
-*end = endptr - (uschar *)mailbox;
+*end = endptr - US mailbox;
 
 /* Although this code has no limitation on the length of address extracted,
 other parts of Exim may have limits, and in any case, RFC 2821 limits local
@@ -820,10 +824,10 @@ We might have an empty address in a group - the caller can choose to ignore
 this. We must, however, keep the flags correct. */
 
 PARSE_FAILED:
-if (parse_found_group && *s == ';')
+if (f.parse_found_group && *s == ';')
   {
-  parse_found_group = FALSE;
-  parse_allow_group = TRUE;
+  f.parse_found_group = FALSE;
+  f.parse_allow_group = TRUE;
   }
 return NULL;
 }
@@ -872,7 +876,7 @@ int hlen;
 BOOL coded = FALSE;
 BOOL first_byte = FALSE;
 
-if (charset == NULL) charset = US"iso-8859-1";
+if (!charset) charset = US"iso-8859-1";
 
 /* We don't expect this to fail! */
 
@@ -909,8 +913,7 @@ for (; len > 0; len--)
       }
     else
       {
-      sprintf(CS t, "=%02X", ch);
-      while (*t != 0) t++;
+      t += sprintf(CS t, "=%02X", ch);
       coded = TRUE;
       first_byte = !first_byte;
       }
@@ -922,7 +925,7 @@ for (; len > 0; len--)
 *t++ = '=';
 *t = 0;
 
-return coded? buffer : string;
+return coded ? buffer : string;
 }
 
 
@@ -1274,10 +1277,10 @@ for (;;)
   However, if the list is empty only because syntax errors were skipped, we
   return FF_DELIVERED. */
 
-  if (*s == 0)
+  if (!*s)
     {
-    return (count > 0 || (syntax_errors != NULL && *syntax_errors != NULL))?
-      FF_DELIVERED : FF_NOTDELIVERED;
+    return (count > 0 || (syntax_errors && *syntax_errors))
+      ?  FF_DELIVERED : FF_NOTDELIVERED;
 
     /* This previous code returns FF_ERROR if nothing is generated but a
     syntax error has been skipped. I now think it is the wrong approach, but
@@ -1393,7 +1396,7 @@ for (;;)
 
     if (flen <= 0)
       {
-      *error = string_sprintf("file name missing after :include:");
+      *error = US"file name missing after :include:";
       return FF_ERROR;
       }
 
@@ -1408,7 +1411,7 @@ for (;;)
 
     /* Insist on absolute path */
 
-    if (filename[0]!= '/')
+    if (filename[0] != '/')
       {
       *error = string_sprintf("included file \"%s\" is not an absolute path",
         filename);
@@ -1417,15 +1420,22 @@ for (;;)
 
     /* Check if include is permitted */
 
-    if ((options & RDO_INCLUDE) != 0)
+    if (options & RDO_INCLUDE)
       {
       *error = US"included files not permitted";
       return FF_ERROR;
       }
 
+    if (is_tainted(filename))
+      {
+      *error = string_sprintf("Tainted name '%s' for included file  not permitted\n",
+       filename);
+      return FF_ERROR;
+      }
+
     /* Check file name if required */
 
-    if (directory != NULL)
+    if (directory)
       {
       int len = Ustrlen(directory);
       uschar *p = filename + len;
@@ -1437,16 +1447,53 @@ for (;;)
         return FF_ERROR;
         }
 
+#ifdef EXIM_HAVE_OPENAT
+      /* It is necessary to check that every component inside the directory
+      is NOT a symbolic link, in order to keep the file inside the directory.
+      This is mighty tedious. We open the directory and openat every component,
+      with a flag that fails symlinks. */
+
+      {
+      int fd = exim_open2(CS directory, O_RDONLY);
+      if (fd < 0)
+	{
+	*error = string_sprintf("failed to open directory %s", directory);
+	return FF_ERROR;
+	}
+      while (*p)
+	{
+	uschar temp;
+	int fd2;
+	uschar * q = p;
+
+	while (*++p && *p != '/') ;
+	temp = *p;
+	*p = '\0';
+
+	fd2 = exim_openat(fd, CS q, O_RDONLY|O_NOFOLLOW);
+	close(fd);
+	*p = temp;
+	if (fd2 < 0)
+	  {
+          *error = string_sprintf("failed to open %s (component of included "
+            "file); could be symbolic link", filename);
+	  return FF_ERROR;
+	  }
+	fd = fd2;
+	}
+      f = fdopen(fd, "rb");
+      }
+#else
       /* It is necessary to check that every component inside the directory
       is NOT a symbolic link, in order to keep the file inside the directory.
       This is mighty tedious. It is also not totally foolproof in that it
       leaves the possibility of a race attack, but I don't know how to do
       any better. */
 
-      while (*p != 0)
+      while (*p)
         {
         int temp;
-        while (*(++p) != 0 && *p != '/');
+        while (*++p && *p != '/');
         temp = *p;
         *p = 0;
         if (Ulstat(filename, &statbuf) != 0)
@@ -1466,11 +1513,16 @@ for (;;)
           return FF_ERROR;
           }
         }
+#endif
       }
 
-    /* Open and stat the file */
+#ifdef EXIM_HAVE_OPENAT
+    else
+#endif
+      /* Open and stat the file */
+      f = Ufopen(filename, "rb");
 
-    if ((f = Ufopen(filename, "rb")) == NULL)
+    if (!f)
       {
       *error = string_open_failed(errno, "included file %s", filename);
       return FF_INCLUDEFAIL;
@@ -1486,7 +1538,7 @@ for (;;)
 
     /* If directory was checked, double check that we opened a regular file */
 
-    if (directory != NULL && (statbuf.st_mode & S_IFMT) != S_IFREG)
+    if (directory && (statbuf.st_mode & S_IFMT) != S_IFREG)
       {
       *error = string_sprintf("included file %s is not a regular file in "
         "the %s directory", filename, directory);
@@ -1502,7 +1554,7 @@ for (;;)
       return FF_ERROR;
       }
 
-    filebuf = store_get(statbuf.st_size + 1);
+    filebuf = store_get(statbuf.st_size + 1, is_tainted(filename));
     if (fread(filebuf, 1, statbuf.st_size, f) != statbuf.st_size)
       {
       *error = string_sprintf("error while reading included file %s: %s",
@@ -1518,10 +1570,9 @@ for (;;)
       error, incoming_domain, directory, syntax_errors);
     if (frc != FF_DELIVERED && frc != FF_NOTDELIVERED) return frc;
 
-    if (addr != NULL)
+    if (addr)
       {
-      last = addr;
-      while (last->next != NULL) { count++; last = last->next; }
+      for (last = addr; last->next; last = last->next) count++;
       last->next = *anchor;
       *anchor = addr;
       count++;
@@ -1563,14 +1614,14 @@ for (;;)
       {
       recipient =
         parse_extract_address(s+1, error, &start, &end, &domain, FALSE);
-      if (recipient != NULL)
-        recipient = (domain != 0)? NULL :
+      if (recipient)
+        recipient = domain != 0 ? NULL :
           string_sprintf("%s@%s", recipient, incoming_domain);
       }
 
     /* Try parsing the item as an address. */
 
-    if (recipient == NULL) recipient =
+    if (!recipient) recipient =
       parse_extract_address(s, error, &start, &end, &domain, FALSE);
 
     /* If item starts with / or | and is not a valid address, or there
@@ -1579,7 +1630,7 @@ for (;;)
 
     if ((*s == '|' || *s == '/') && (recipient == NULL || domain == 0))
       {
-      uschar *t = store_get(Ustrlen(s) + 1);
+      uschar *t = store_get(Ustrlen(s) + 1, is_tainted(s));
       uschar *p = t;
       uschar *q = s;
       while (*q != 0)
@@ -1618,7 +1669,7 @@ for (;;)
 
         if (syntax_errors != NULL)
           {
-          error_block *e = store_get(sizeof(error_block));
+          error_block *e = store_get(sizeof(error_block), FALSE);
           error_block *last = *syntax_errors;
           if (last == NULL) *syntax_errors = e; else
             {
@@ -1686,6 +1737,7 @@ parse_message_id(uschar *str, uschar **yield, uschar **error)
 {
 uschar *domain = NULL;
 uschar *id;
+rmark reset_point;
 
 str = skip_comment(str);
 if (*str != '<')
@@ -1698,27 +1750,28 @@ if (*str != '<')
 for the answer, but it may also be very long if we are processing a header
 line. Therefore, take care to release unwanted store afterwards. */
 
-id = *yield = store_get(Ustrlen(str) + 1);
+reset_point = store_mark();
+id = *yield = store_get(Ustrlen(str) + 1, is_tainted(str));
 *id++ = *str++;
 
 str = read_addr_spec(str, id, '>', error, &domain);
 
-if (*error == NULL)
+if (!*error)
   {
   if (*str != '>') *error = US"Missing '>' after message-id";
     else if (domain == NULL) *error = US"domain missing in message-id";
   }
 
-if (*error != NULL)
+if (*error)
   {
-  store_reset(*yield);
+  store_reset(reset_point);
   return NULL;
   }
 
-while (*id != 0) id++;
+while (*id) id++;
 *id++ = *str++;
 *id++ = 0;
-store_reset(id);
+store_release_above(id);
 
 str = skip_comment(str);
 return str;
@@ -2074,7 +2127,9 @@ while (Ufgets(buffer, sizeof(buffer), stdin) != NULL)
   buffer[Ustrlen(buffer) - 1] = 0;
   if (buffer[0] == 0) break;
   out = parse_extract_address(buffer, &errmess, &start, &end, &domain, FALSE);
-  if (out == NULL) printf("*** bad address: %s\n", errmess); else
+  if (!out)
+    printf("*** bad address: %s\n", errmess);
+  else
     {
     uschar extract[1024];
     Ustrncpy(extract, buffer+start, end-start);
@@ -2093,7 +2148,9 @@ while (Ufgets(buffer, sizeof(buffer), stdin) != NULL)
   buffer[Ustrlen(buffer) - 1] = 0;
   if (buffer[0] == 0) break;
   out = parse_extract_address(buffer, &errmess, &start, &end, &domain, FALSE);
-  if (out == NULL) printf("*** bad address: %s\n", errmess); else
+  if (!out)
+    printf("*** bad address: %s\n", errmess);
+  else
     {
     uschar extract[1024];
     Ustrncpy(extract, buffer+start, end-start);
@@ -2105,7 +2162,7 @@ allow_utf8_domains = FALSE;
 
 printf("Testing parse_extract_address with group syntax\n");
 
-parse_allow_group = TRUE;
+f.parse_allow_group = TRUE;
 while (Ufgets(buffer, sizeof(buffer), stdin) != NULL)
   {
   uschar *out;
@@ -2114,7 +2171,7 @@ while (Ufgets(buffer, sizeof(buffer), stdin) != NULL)
   buffer[Ustrlen(buffer) - 1] = 0;
   if (buffer[0] == 0) break;
   s = buffer;
-  while (*s != 0)
+  while (*s)
     {
     uschar *ss = parse_find_address_end(s, FALSE);
     int terminator = *ss;
@@ -2122,7 +2179,9 @@ while (Ufgets(buffer, sizeof(buffer), stdin) != NULL)
     out = parse_extract_address(buffer, &errmess, &start, &end, &domain, FALSE);
     *ss = terminator;
 
-    if (out == NULL) printf("*** bad address: %s\n", errmess); else
+    if (!out)
+      printf("*** bad address: %s\n", errmess);
+    else
       {
       uschar extract[1024];
       Ustrncpy(extract, buffer+start, end-start);
@@ -2131,7 +2190,7 @@ while (Ufgets(buffer, sizeof(buffer), stdin) != NULL)
       }
 
     s = ss + (terminator? 1:0);
-    while (isspace(*s)) s++;
+    Uskip_whitespace(&s);
     }
   }