From 91e064d0fdbc45f75f3e2e181ee84d8e879ac91c Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Tue, 25 Aug 2015 15:48:37 +0100
Subject: [PATCH] Add folded version of base64 encoding

---
 src/libutil/str_util.c | 25 ++++++++++++++++++++++---
 src/libutil/str_util.h | 10 ++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/src/libutil/str_util.c b/src/libutil/str_util.c
index 00ef4e4ed..75a200db5 100644
--- a/src/libutil/str_util.c
+++ b/src/libutil/str_util.c
@@ -565,13 +565,15 @@ rspamd_decode_base32 (const gchar *in, gsize inlen, gsize *outlen)
 }
 
 
-gchar *
-rspamd_encode_base64 (const guchar *in, gsize inlen, gint str_len, gsize *outlen)
+static gchar *
+rspamd_encode_base64_common (const guchar *in, gsize inlen, gint str_len,
+		gsize *outlen, gboolean fold)
 {
 #define CHECK_SPLIT \
 	do { if (str_len > 0 && cols >= str_len) { \
 				*o++ = '\r'; \
 				*o++ = '\n'; \
+				if (fold) *o++ = '\t'; \
 				cols = 0; \
 	} } \
 while (0)
@@ -588,7 +590,7 @@ while (0)
 
 	if (str_len > 0) {
 		g_assert (str_len > 8);
-		allocated_len += (allocated_len / str_len + 1) * 2 + 1;
+		allocated_len += (allocated_len / str_len + 1) * (fold ? 3 : 2) + 1;
 	}
 
 	out = g_malloc (allocated_len);
@@ -621,6 +623,9 @@ while (0)
 
 			*o++ = '\r';
 			*o++ = '\n';
+			if (fold) {
+				*o ++ = '\t';
+			}
 
 			/* Remaining bytes */
 			while (shift >= 16) {
@@ -708,6 +713,20 @@ end:
 	return out;
 }
 
+gchar *
+rspamd_encode_base64 (const guchar *in, gsize inlen, gint str_len,
+		gsize *outlen)
+{
+	return rspamd_encode_base64_common (in, inlen, str_len, outlen, FALSE);
+}
+
+gchar *
+rspamd_encode_base64_fold (const guchar *in, gsize inlen, gint str_len,
+		gsize *outlen)
+{
+	return rspamd_encode_base64_common (in, inlen, str_len, outlen, TRUE);
+}
+
 gsize
 rspamd_decode_url (gchar *dst, const gchar *src, gsize size)
 {
diff --git a/src/libutil/str_util.h b/src/libutil/str_util.h
index e07c51701..f8d9dd4dc 100644
--- a/src/libutil/str_util.h
+++ b/src/libutil/str_util.h
@@ -128,6 +128,16 @@ guchar* rspamd_decode_base32 (const gchar *in, gsize inlen, gsize *outlen);
 gchar * rspamd_encode_base64 (const guchar *in, gsize inlen, gint str_len,
 		gsize *outlen);
 
+/**
+ * Encode and fold string using base64 encoding
+ * @param in input
+ * @param inlen input length
+ * @param str_len maximum string length (if <= 0 then no lines are split)
+ * @return freshly allocated base64 encoded value or NULL if input is invalid
+ */
+gchar * rspamd_encode_base64_fold (const guchar *in, gsize inlen, gint str_len,
+		gsize *outlen);
+
 /**
  * Decode URL encoded string in-place and return new length of a string, src and dst are NULL terminated
  * @param dst
-- 
2.39.5