A compressed stream may end with an empty packet, and PGP decompression
finished before reading this empty packet in the remaining stream. This
caused a failure in pgcrypto, handling this case as corrupted data.
This commit makes sure to consume such extra data, avoiding a failure
when decompression the entire stream. This corner case was reproducible
with a data length of 16kB, and existed since its introduction in
e94dd6a. A cheap regression test is added to cover this case.
Thanks to Jeff Janes for the extra investigation.
Reported-by: Frank Gagnepain
Author: Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/16476-
692ef7b84e5fb893@postgresql.org
Backpatch-through: 9.5
index 32b350b8fe05b118b2271181f890cfbfabef23ea..d4c57feba30b84dc86c6a8287dbfef4c69fbf71e 100644 (file)
Secret message
(1 row)
+-- check corner case involving an input string of 16kB, as per bug #16476.
+SELECT setseed(0);
+ setseed
+---------
+
+(1 row)
+
+WITH random_string AS
+(
+ -- This generates a random string of 16366 bytes. This is chosen
+ -- as random so that it does not get compressed, and the decompression
+ -- would work on a string with the same length as the origin, making the
+ -- test behavior more predictible. lpad() ensures that the generated
+ -- hexadecimal value is completed by extra zero characters if random()
+ -- has generated a value strictly lower than 16.
+ SELECT string_agg(decode(lpad(to_hex((random()*256)::int), 2, '0'), 'hex'), '') as bytes
+ FROM generate_series(0, 16365)
+)
+SELECT bytes =
+ pgp_sym_decrypt_bytea(
+ pgp_sym_encrypt_bytea(bytes, 'key',
+ 'compress-algo=1,compress-level=1'),
+ 'key', 'expect-compress-algo=1')
+ AS is_same
+ FROM random_string;
+ is_same
+---------
+ t
+(1 row)
+
index eaeb221877f9119ffdbd5029bfb3883e46d7a4cb..141067708c5d50e2a1af8475660ed311a641dc03 100644 (file)
@@ -244,6 +244,17 @@ decompress_read(void *priv, PullFilter *src, int len,
struct DecomprData *dec = priv;
restart:
+ if (dec->stream.avail_in == 0)
+ {
+ uint8 *tmp;
+
+ res = pullf_read(src, 8192, &tmp);
+ if (res < 0)
+ return res;
+ dec->stream.next_in = tmp;
+ dec->stream.avail_in = res;
+ }
+
if (dec->buf_data > 0)
{
if (len > dec->buf_data)
if (dec->eof)
return 0;
- if (dec->stream.avail_in == 0)
- {
- uint8 *tmp;
-
- res = pullf_read(src, 8192, &tmp);
- if (res < 0)
- return res;
- dec->stream.next_in = tmp;
- dec->stream.avail_in = res;
- }
-
dec->stream.next_out = dec->buf;
dec->stream.avail_out = dec->buf_len;
dec->pos = dec->buf;
index ca9ee1fc0088a3416ff557853c8c26fda524f3c0..87c59c6cabc4e7f380992c28625b12e662e1722b 100644 (file)
pgp_sym_encrypt('Secret message', 'key',
'compress-algo=2, compress-level=0'),
'key', 'expect-compress-algo=0');
+
+-- check corner case involving an input string of 16kB, as per bug #16476.
+SELECT setseed(0);
+WITH random_string AS
+(
+ -- This generates a random string of 16366 bytes. This is chosen
+ -- as random so that it does not get compressed, and the decompression
+ -- would work on a string with the same length as the origin, making the
+ -- test behavior more predictible. lpad() ensures that the generated
+ -- hexadecimal value is completed by extra zero characters if random()
+ -- has generated a value strictly lower than 16.
+ SELECT string_agg(decode(lpad(to_hex((random()*256)::int), 2, '0'), 'hex'), '') as bytes
+ FROM generate_series(0, 16365)
+)
+SELECT bytes =
+ pgp_sym_decrypt_bytea(
+ pgp_sym_encrypt_bytea(bytes, 'key',
+ 'compress-algo=1,compress-level=1'),
+ 'key', 'expect-compress-algo=1')
+ AS is_same
+ FROM random_string;