From 9cbe1283f70699b82ca4225705d40fcc73633dfb Mon Sep 17 00:00:00 2001 From: "Christoph M. Becker" Date: Sat, 22 Sep 2018 15:20:20 +0200 Subject: [PATCH] Fix #66828: iconv_mime_encode Q-encoding longer than it should be Before the fix for bug 48289 has been applied, the algorithm to construct a Q-encoded-word has been optimistic, i.e. try to encode as many bytes that *may* fit in the remaining space, calculate the actual length of the Q-encoded word, and if it's too long, try again with a reduced size. However, the fix for the mentioned bug replaced this by a pessimistic algorithm, which always terminates[1] the for loop[2] during the first iteration (which renders the following 3 lines as dead code), and as such easily produces unnecessarily short encoded-words. Instead the proper fix for the bug would have been to make sure that `out_size` is always decremented, if the space isn't sufficient for the encoded-word. [1] [2] --- NEWS | 4 ++++ ext/iconv/iconv.c | 4 ++-- ext/iconv/tests/bug66828.phpt | 21 +++++++++++++++++++++ 3 files changed, 27 insertions(+), 2 deletions(-) create mode 100644 ext/iconv/tests/bug66828.phpt diff --git a/NEWS b/NEWS index 1add82df49..00ee93ea43 100644 --- a/NEWS +++ b/NEWS @@ -10,6 +10,10 @@ PHP NEWS . Fixed bug #76480 (Use curl_multi_wait() so that timeouts are respected). (Pierrick) +- iconv: + . Fixed bug #66828 (iconv_mime_encode Q-encoding longer than it should be). + (cmb) + - Opcache: . Fixed bug #76832 (ZendOPcache.MemoryBase periodically deleted by the OS). (Anatol) diff --git a/ext/iconv/iconv.c b/ext/iconv/iconv.c index de5bccbb97..ef27b20645 100644 --- a/ext/iconv/iconv.c +++ b/ext/iconv/iconv.c @@ -1367,7 +1367,7 @@ static php_iconv_err_t _php_iconv_mime_encode(smart_str *pretval, const char *fn prev_in_left = ini_in_left = in_left; ini_in_p = in_p; - for (out_size = (char_cnt - 2) / 3; out_size > 0;) { + for (out_size = (char_cnt - 2); out_size > 0;) { #if !ICONV_SUPPORTS_ERRNO size_t prev_out_left; #endif @@ -1431,7 +1431,7 @@ static php_iconv_err_t _php_iconv_mime_encode(smart_str *pretval, const char *fn break; } - out_size -= ((nbytes_required - (char_cnt - 2)) + 1) / 3; + out_size -= ((nbytes_required - (char_cnt - 2)) + 2) / 3; in_left = ini_in_left; in_p = ini_in_p; } diff --git a/ext/iconv/tests/bug66828.phpt b/ext/iconv/tests/bug66828.phpt new file mode 100644 index 0000000000..9914b41b14 --- /dev/null +++ b/ext/iconv/tests/bug66828.phpt @@ -0,0 +1,21 @@ +--TEST-- +Bug #66828 (iconv_mime_encode Q-encoding longer than it should be) +--SKIPIF-- + +--FILE-- + "ISO-8859-1", + "output-charset" => "UTF-8", + "line-length" => 76, + "line-break-chars" => "\n", + "scheme" => "Q" +); +var_dump(iconv_mime_encode("Subject", "Test Test Test Test Test Test Test Test", $preferences)); +?> +===DONE=== +--EXPECT-- +string(74) "Subject: =?UTF-8?Q?Test=20Test=20Test=20Test=20Test=20Test=20Test=20Test?=" +===DONE=== -- 2.49.0