From e2513bfe8db91055e443e1804e3abb90c9998d86 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dani=C3=ABl=20van=20de=20Giessen?= Date: Thu, 27 Aug 2020 14:16:48 +0200 Subject: [PATCH] extmod/moduzlib: Fix parsing zlib header dict size. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From RFC 1950 section 2.2: "CINFO is the base-2 logarithm of the LZ77 window size, minus eight (CINFO=7 indicates a 32K window size)" Signed-off-by: Daniël van de Giessen --- extmod/moduzlib.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/extmod/moduzlib.c b/extmod/moduzlib.c index f78c34908..a6874fb4e 100644 --- a/extmod/moduzlib.c +++ b/extmod/moduzlib.c @@ -77,7 +77,7 @@ STATIC mp_obj_t decompio_make_new(const mp_obj_type_t *type, size_t n_args, size o->eof = false; mp_int_t dict_opt = 0; - int dict_sz; + uint dict_sz; if (n_args > 1) { dict_opt = mp_obj_get_int(args[1]); } @@ -94,7 +94,10 @@ STATIC mp_obj_t decompio_make_new(const mp_obj_type_t *type, size_t n_args, size header_error: mp_raise_ValueError(MP_ERROR_TEXT("compression header")); } - dict_sz = 1 << dict_opt; + // RFC 1950 section 2.2: + // CINFO is the base-2 logarithm of the LZ77 window size, + // minus eight (CINFO=7 indicates a 32K window size) + dict_sz = 1 << (dict_opt + 8); } else { dict_sz = 1 << -dict_opt; } @@ -116,6 +119,7 @@ STATIC mp_uint_t decompio_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *er o->eof = true; } if (st < 0) { + DEBUG_printf("uncompress error=" INT_FMT "\n", st); *errcode = MP_EINVAL; return MP_STREAM_ERROR; }