[gmime-devel] Wrong results of g_mime_encoding_outlen

[Damian Pietras <daper daper net>]

I've hit a bug in gmime 2.4.15 while composing a message. Gmime is
segfaulting if I use GMIME_CONTENT_ENCODING_QUOTEDPRINTABLE. Valgrind
says it's a buffer overflow while encoding to quoted printable.

It's right, in a simple test case that encodes mostly binary data
using GMIME_CONTENT_ENCODING_QUOTEDPRINTABLE a buffer overrun occurs in
g_mime_encoding_quoted_encode_step.

I think the reason is that GMIME_QP_ENCODE_LEN looks like:

#define GMIME_QP_ENCODE_LEN(x)     ((size_t) ((((x) + 1) * 3) + 1))

is wrong because g_mime_encoding_quoted_encode_step inserts an EOL
char after every 74th output character which the macro doesn't take
into account. The bug doesn't occur if using base64 encoding.

-- 
Damian Pietras

http://www.linuxprogrammingblog.com