postgres.git / summary / log / commit / refs
commit bba2e66aec4c8af4ad8b3be0d7cde1a97c974a00
Author: Michael Paquier <michael@paquier.xyz>
Date: Wed Jul 22 05:52:46 2020 +0000
First released in: master (reverted before release), REL9_5_STABLE (reverted before release), REL9_6_STABLE (reverted before release), REL_10_STABLE (reverted before release), REL_11_STABLE (reverted before release), REL_12_STABLE (reverted before release), REL_13_STABLE (reverted before release)
Reverted by: 43e21fd8f6e8 (in 9.5.23), 11c320dcebc0 (in 9.6.19), 9a3c895084c6 (in 10.14), 6ae2d925b131 (in 11.9), e30a63f258f5 (in 12.4), 9f5162ef43c5 (in 13.0), 38f60f174e32 (in 14.0)
Fix corner case with PGP decompression in pgcrypto
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
contrib/pgcrypto/expected/pgp-compression.out | 30 +++++++++++++++++++++++++++
contrib/pgcrypto/pgp-compress.c | 22 ++++++++++----------
contrib/pgcrypto/sql/pgp-compression.sql | 21 +++++++++++++++++++
3 files changed, 62 insertions(+), 11 deletions(-)
diff --git a/contrib/pgcrypto/expected/pgp-compression.out b/contrib/pgcrypto/expected/pgp-compression.out
index 32b350b8fe0..d4c57feba30 100644
--- a/contrib/pgcrypto/expected/pgp-compression.out
+++ b/contrib/pgcrypto/expected/pgp-compression.out
@@ -48,3 +48,33 @@ select pgp_sym_decrypt(
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)
+
diff --git a/contrib/pgcrypto/pgp-compress.c b/contrib/pgcrypto/pgp-compress.c
index eaeb221877f..141067708c5 100644
--- a/contrib/pgcrypto/pgp-compress.c
+++ b/contrib/pgcrypto/pgp-compress.c
@@ -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)
@@ -257,17 +268,6 @@ restart:
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;
diff --git a/contrib/pgcrypto/sql/pgp-compression.sql b/contrib/pgcrypto/sql/pgp-compression.sql
index ca9ee1fc008..87c59c6cabc 100644
--- a/contrib/pgcrypto/sql/pgp-compression.sql
+++ b/contrib/pgcrypto/sql/pgp-compression.sql
@@ -28,3 +28,24 @@ select pgp_sym_decrypt(
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;
[parent: 171633ff5d8e]