From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Wed, 4 Sep 2019 10:33:08 +0000 (+0200)
Subject: lib: base64 - Fix dest buffer assertion in base64_decode_more().
X-Git-Tag: 2.3.8~101
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=692d678a029278a23d2cecbc5205f381661bae79;p=thirdparty%2Fdovecot%2Fcore.git

lib: base64 - Fix dest buffer assertion in base64_decode_more().

The assertion is supposed to trigger when the encoder hits the buffer size limit
unexpectedly (src_pos_r==NULL means that all should be encoded at once). It
triggered erroneously when the destination buffer had the exact size needed
for the encoded data.
---

diff --git a/src/lib/base64.c b/src/lib/base64.c
index 60ceb132f9..fb6cd635e6 100644
--- a/src/lib/base64.c
+++ b/src/lib/base64.c
@@ -591,8 +591,10 @@ int base64_decode_more(struct base64_decoder *dec,
 			i_unreached();
 		}
 		if (dst_avail == 0) {
-			i_assert(src_pos_r != NULL);
-			*src_pos_r = src_pos + 1;
+			if (src_pos_r != NULL)
+				*src_pos_r = src_pos + 1;
+			else
+				i_assert(src_pos + 1 == src_size);
 			return 1;
 		}
 	}