From 275cdcc8d92f7cd9ca77ac25282b52c3d2dbaaf7 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Tue, 3 Apr 2018 15:36:41 +0100
Subject: [PATCH] [Fix] Another fix in folding algorithm

---
 src/libserver/dkim.c   | 25 ++++++++++++-------
 src/libutil/str_util.c | 54 ++++++++++++++++++++++++++++++------------
 2 files changed, 55 insertions(+), 24 deletions(-)

diff --git a/src/libserver/dkim.c b/src/libserver/dkim.c
index 8e264a99a..f2914535f 100644
--- a/src/libserver/dkim.c
+++ b/src/libserver/dkim.c
@@ -2760,7 +2760,7 @@ rspamd_dkim_sign (struct rspamd_task *task, const gchar *selector,
 	gchar *b64_data;
 	guchar *rsa_buf;
 	guint rsa_len;
-	guint headers_len = 0;
+	guint headers_len = 0, cur_len = 0;
 	union rspamd_dkim_header_stat hstat;
 
 	g_assert (ctx != NULL);
@@ -2856,7 +2856,13 @@ rspamd_dkim_sign (struct rspamd_task *task, const gchar *selector,
 			}
 
 			/* Now add one more entry to oversign */
-			headers_len += (strlen (dh->name) + 1) * (count + 1);
+			cur_len = (strlen (dh->name) + 1) * (count + 1);
+			headers_len += cur_len;
+			if (headers_len > 70 && i > 0 && i < ctx->common.hlist->len - 1) {
+				rspamd_printf_gstring (hdr, "  ");
+				headers_len = cur_len;
+			}
+
 			for (j = 0; j < count + 1; j++) {
 				rspamd_printf_gstring (hdr, "%s:", dh->name);
 			}
@@ -2864,11 +2870,16 @@ rspamd_dkim_sign (struct rspamd_task *task, const gchar *selector,
 		else {
 			if (hstat.s.count > 0) {
 
+				cur_len = (strlen (dh->name) + 1) * (hstat.s.count);
+				headers_len += cur_len;
+				if (headers_len > 70 && i > 0 && i < ctx->common.hlist->len - 1) {
+					rspamd_printf_gstring (hdr, "  ");
+					headers_len = cur_len;
+				}
+
 				for (j = 0; j < hstat.s.count; j++) {
 					rspamd_printf_gstring (hdr, "%s:", dh->name);
 				}
-
-				headers_len += (strlen (dh->name) + 1) * (hstat.s.count);
 			}
 
 			if (g_hash_table_lookup (task->raw_headers, dh->name)) {
@@ -2877,16 +2888,12 @@ rspamd_dkim_sign (struct rspamd_task *task, const gchar *selector,
 			}
 		}
 
-		if (headers_len > 60 && i < ctx->common.hlist->len - 1) {
-			rspamd_printf_gstring (hdr, "  ");
-			headers_len = 0;
-		}
-
 		g_hash_table_remove (ctx->common.htable, dh->name);
 	}
 
 	/* Replace the last ':' with ';' */
 	hdr->str[hdr->len - 1] = ';';
+	msg_err ("%v", hdr);
 
 	if (ctx->common.type != RSPAMD_DKIM_ARC_SEAL) {
 		if (!cached_bh->digest_normal) {
diff --git a/src/libutil/str_util.c b/src/libutil/str_util.c
index 4d1b22076..d571efabb 100644
--- a/src/libutil/str_util.c
+++ b/src/libutil/str_util.c
@@ -925,6 +925,8 @@ rspamd_header_value_fold (const gchar *name,
 	const guint default_fold_max = 76;
 	guint cur_len;
 	const gchar *p, *c;
+	guint nspaces = 0;
+	const gchar *last;
 	gboolean first_token = TRUE;
 	enum {
 		fold_before = 0,
@@ -954,6 +956,7 @@ rspamd_header_value_fold (const gchar *name,
 
 	while (*p) {
 		switch (state) {
+
 		case read_token:
 			if (fold_on_chars && strchr (fold_on_chars, *p) != NULL) {
 				fold_type = fold_after;
@@ -1028,9 +1031,7 @@ rspamd_header_value_fold (const gchar *name,
 		case fold_token:
 			/* Here, we have token start at 'c' and token end at 'p' */
 			if (fold_type == fold_after) {
-				guint nspaces = 0;
-				const gchar *last;
-
+				nspaces = 0;
 				if (p > c) {
 					g_string_append_len (res, c, p - c);
 
@@ -1074,27 +1075,50 @@ rspamd_header_value_fold (const gchar *name,
 				cur_len = 0;
 			}
 			else {
+				const gchar *last;
+
 				/* Skip space if needed */
 				if (g_ascii_isspace (*c) && p > c) {
 					c ++;
 				}
 
-				switch (how) {
-				case RSPAMD_TASK_NEWLINES_LF:
-					g_string_append_len (res, "\n\t", 2);
-					break;
-				case RSPAMD_TASK_NEWLINES_CR:
-					g_string_append_len (res, "\r\t", 2);
-					break;
-				case RSPAMD_TASK_NEWLINES_CRLF:
-				default:
-					g_string_append_len (res, "\r\n\t", 3);
-					break;
+				/* Avoid double folding */
+				last = &res->str[res->len - 1];
+				last --;
+
+				if (*last != '\r' && *last != '\n') {
+					last ++;
+					while (g_ascii_isspace (*last)) {
+						last --;
+						nspaces ++;
+						res->len --;
+					}
+
+					switch (how) {
+					case RSPAMD_TASK_NEWLINES_LF:
+						g_string_append_len (res, "\n\t", 2);
+						break;
+					case RSPAMD_TASK_NEWLINES_CR:
+						g_string_append_len (res, "\r\t", 2);
+						break;
+					case RSPAMD_TASK_NEWLINES_CRLF:
+					default:
+						g_string_append_len (res, "\r\n\t", 3);
+						break;
+					}
+				}
+
+				/* Move leftover spaces */
+				cur_len = nspaces;
+
+				while (nspaces) {
+					g_string_append_c (res, ' ');
+					nspaces --;
 				}
 
 				if (p > c) {
 					g_string_append_len (res, c, p - c);
-					cur_len = p - c;
+					cur_len += p - c;
 				}
 				else {
 					cur_len = 0;
-- 
2.39.5