From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Tue, 3 Sep 2019 16:15:57 +0000 (+0200)
Subject: lib: base64 - Allow encoding line endings one octet at a time.
X-Git-Tag: 2.3.8~106
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ec9e358b04fd681d92a1a6cd504d067ba65590d0;p=thirdparty%2Fdovecot%2Fcore.git

lib: base64 - Allow encoding line endings one octet at a time.
---

diff --git a/src/lib/base64.c b/src/lib/base64.c
index 9aec963b58..9518254e80 100644
--- a/src/lib/base64.c
+++ b/src/lib/base64.c
@@ -327,14 +327,20 @@ bool base64_encode_more(struct base64_encoder *enc,
 			dst_avail -= written;
 		}
 
+		if (dst_avail == 0)
+			break;
+
+		i_assert(enc->w_buf_len < sizeof(enc->w_buf));
 		if (src_size > 0 && enc->cur_line_len == enc->max_line_len) {
 			if (HAS_ALL_BITS(enc->flags, BASE64_ENCODE_FLAG_CRLF)) {
-				if (dst_avail < 2)
-					break;
-				buffer_append(dest, "\r\n", 2);
+				if (dst_avail >= 2)
+					buffer_append(dest, "\r\n", 2);
+				else {
+					buffer_append_c(dest, '\r');
+					enc->w_buf[enc->w_buf_len] = '\n';
+					enc->w_buf_len++;
+				}
 			} else {
-				if (dst_avail < 1)
-					break;
 				buffer_append_c(dest, '\n');
 			}
 			enc->cur_line_len = 0;
diff --git a/src/lib/base64.h b/src/lib/base64.h
index 3e4e110b0e..f777619d8b 100644
--- a/src/lib/base64.h
+++ b/src/lib/base64.h
@@ -38,7 +38,7 @@ struct base64_encoder {
 	unsigned char buf;
 	size_t cur_line_len;
 
-	unsigned char w_buf[4];
+	unsigned char w_buf[5];
 	unsigned int w_buf_len;
 
 	bool finished:1;