[Fix] Add obs_fws state support to eoh state machine

Issue: #2584

diff --git a/src/libutil/str_util.c b/src/libutil/str_util.c
index 09817a34417d3b5f882b4f6966bf015925f10fdd..4f7aa1c972b6d7a33dfbb456fcbd8ceaad5ee2c4 100644 (file)
--- a/src/libutil/str_util.c
+++ b/src/libutil/str_util.c
@@ -1428,7 +1428,8 @@ rspamd_string_find_eoh (GString *input, goffset *body_start)
                got_lf,
                got_linebreak,
                got_linebreak_cr,
-               got_linebreak_lf
+               got_linebreak_lf,
+               obs_fws
        } state = skip_char;
 
        g_assert (input != NULL);
@@ -1478,7 +1479,9 @@ rspamd_string_find_eoh (GString *input, goffset *body_start)
                        }
                        else if (g_ascii_isspace (*p)) {
                                /* We have \r<space>*, allow to stay in this state */
+                               c = p;
                                p ++;
+                               state = obs_fws;
                        }
                        else {
                                p++;
@@ -1498,7 +1501,9 @@ rspamd_string_find_eoh (GString *input, goffset *body_start)
                        }
                        else if (g_ascii_isspace (*p)) {
                                /* We have \n<space>*, allow to stay in this state */
+                               c = p;
                                p ++;
+                               state = obs_fws;
                        }
                        else {
                                p++;
@@ -1518,7 +1523,9 @@ rspamd_string_find_eoh (GString *input, goffset *body_start)
                        }
                        else if (g_ascii_isspace (*p)) {
                                /* We have <linebreak><space>*, allow to stay in this state */
+                               c = p;
                                p ++;
+                               state = obs_fws;
                        }
                        else {
                                p++;
@@ -1537,6 +1544,8 @@ rspamd_string_find_eoh (GString *input, goffset *body_start)
                        }
                        else if (g_ascii_isspace (*p)) {
                                /* We have \r\n<space>*, allow to keep in this state */
+                               c = p;
+                               state = obs_fws;
                                p ++;
                        }
                        else {
@@ -1552,7 +1561,95 @@ rspamd_string_find_eoh (GString *input, goffset *body_start)
                        }
 
                        return c - input->str;
+               case obs_fws:
+                       if (*p == ' ' || *p == '\t') {
+                               p ++;
+                       }
+                       else if (*p == '\r') {
+                               /* Perform lookahead due to #2349 */
+                               if (end - p > 2) {
+                                       if (p[1] == '\n' && g_ascii_isspace (p[2])) {
+                                               /* Real obs_fws state, switch */
+                                               c = p;
+                                               p ++;
+                                               state = got_cr;
+                                       }
+                                       else if (g_ascii_isspace (p[1])) {
+                                               p ++;
+                                               state = obs_fws;
+                                       }
+                                       else {
+                                               /*
+                                                * newline wsp+ \r <nwsp>, hence:
+                                                * c -> eoh
+                                                * p + 1 -> body start
+                                                */
+                                               if (body_start) {
+                                                       /* \r\n\r\n */
+                                                       *body_start = p - input->str + 1;
+                                               }
+
+                                               return c - input->str;
+                                       }
+                               }
+                               else {
+                                       /* shortage */
+                                       if (body_start) {
+                                               *body_start = p - input->str + 1;
+                                       }
+
+                                       return p - input->str;
+                               }
+                       }
+                       else if (*p == '\n') {
+                               /* Perform lookahead due to #2349 */
+                               if (end - p > 1) {
+                                       if (p[1] == ' ' || p[1] == '\t') {
+                                               c = p;
+                                               p ++;
+                                               state = obs_fws;
+                                       }
+                                       else if (p[1] == '\r') {
+                                               c = p;
+                                               p ++;
+                                               state = got_lf;
+                                       }
+                                       else if (p[1] == '\n') {
+                                               c = p;
+                                               p ++;
+                                               state = got_lf;
+                                       }
+                                       else {
+                                               /*
+                                                * newline wsp+ \n <nwsp>, hence:
+                                                * c -> eoh
+                                                * p + 1 -> body start
+                                                */
+                                               if (body_start) {
+                                                       /* \r\n\r\n */
+                                                       *body_start = p - input->str + 1;
+                                               }
+
+                                               return c - input->str;
+                                       }
+
+                               }
+                               else {
+                                       /* shortage */
+                                       if (body_start) {
+                                               *body_start = p - input->str + 1;
+                                       }
+
+                                       return p - input->str;
+                               }
+                       }
+                       else {
+                               p++;
+                               state = skip_char;
+                       }
+                       break;
                }
+
        }
 
        if (state == got_linebreak_lf) {