qcdm: fix CRC checking on some packets

Should be pointing to the CRC location in the *unescaped* packet
buffer since the CRC is subject to escaping/unescaping.  Previous
code pointed to the wrong location in the escaped packet buffer,
which was often pointing to the write place if there weren't many
escaped bytes in the input buffer, but was still wrong.

5 files changed, 92 insertions, 1 deletions

diff --git a/libqcdm/src/utils.c b/libqcdm/src/utils.c
index ab281557..9b9ac5f0 100644
--- a/libqcdm/src/utils.c
+++ b/libqcdm/src/utils.c
@@ -296,7 +296,7 @@ dm_decapsulate_buffer (const char *inbuf,
 
     /* Check the CRC of the packet's data */
     crc = crc16 (outbuf, unesc_len - 2);
-    pkt_crc = *((guint16 *) &outbuf[pkt_len - 2]);
+    pkt_crc = *((guint16 *) &outbuf[unesc_len - 2]);
     if (crc != GUINT_FROM_LE (pkt_crc)) {
         *out_used = pkt_len + 1; /* packet + CRC + 0x7E */
         return FALSE;
diff --git a/libqcdm/tests/Makefile.am b/libqcdm/tests/Makefile.am
index 3d1b7ba5..eb38fdbb 100644
--- a/libqcdm/tests/Makefile.am
+++ b/libqcdm/tests/Makefile.am
@@ -8,6 +8,8 @@ test_qcdm_SOURCES = \
 	test-qcdm-crc.h \
 	test-qcdm-escaping.c \
 	test-qcdm-escaping.h \
+	test-qcdm-utils.c \
+	test-qcdm-utils.h \
 	test-qcdm-com.c \
 	test-qcdm-com.h \
 	test-qcdm-result.c \
diff --git a/libqcdm/tests/test-qcdm-utils.c b/libqcdm/tests/test-qcdm-utils.c
new file mode 100644
index 00000000..34de8394
--- /dev/null
+++ b/libqcdm/tests/test-qcdm-utils.c
@@ -0,0 +1,63 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * Copyright (C) 2010 Red Hat, Inc.
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <glib.h>
+#include <string.h>
+
+#include "test-qcdm-utils.h"
+#include "utils.h"
+
+static const char inbuf[] = {
+    0x40, 0x03, 0x00, 0x01, 0x00, 0x19, 0xf0, 0x00, 0x16, 0x00, 0x21, 0x00,
+    0x1c, 0x00, 0xd8, 0x00, 0x3f, 0x00, 0x56, 0x01, 0x3f, 0x00, 0x15, 0x00,
+    0x1a, 0x00, 0x11, 0x01, 0x3f, 0x00, 0x92, 0x01, 0x3f, 0x00, 0x39, 0x00,
+    0x3f, 0x00, 0x95, 0x01, 0x3f, 0x00, 0x12, 0x00, 0x3f, 0x00, 0x23, 0x01,
+    0x3f, 0x00, 0x66, 0x00, 0x3f, 0x00, 0x0b, 0x01, 0x3f, 0x00, 0xae, 0x00,
+    0x3f, 0x00, 0x02, 0x01, 0x3f, 0x00, 0xa8, 0x00, 0x3f, 0x00, 0x50, 0x01,
+    0x3f, 0x00, 0xf8, 0x01, 0x3f, 0x00, 0x57, 0x00, 0x3f, 0x00, 0x7d, 0x5e,
+    0x00, 0x3f, 0x00, 0x93, 0x00, 0x3f, 0x00, 0xbd, 0x00, 0x3f, 0x00, 0x77,
+    0x01, 0x3f, 0x00, 0xb7, 0x00, 0x3f, 0x00, 0xab, 0x00, 0x3f, 0x00, 0x33,
+    0x00, 0x3f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0xad, 0xde, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x13,
+    0x13, 0x50, 0x1f, 0x00, 0x00, 0xff, 0xff, 0x00, 0xaa, 0x19, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb1, 0xc4, 0x7d, 0x5e,
+    0x7d, 0x5e, 0x7d, 0x5d, 0x5d, 0x04, 0x58, 0x1b, 0x5b, 0x1b, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x65, 0x69, 0x7e
+};
+
+void
+test_utils_decapsulate_buffer (void *f, void *data)
+{
+    gboolean success;
+    char outbuf[512];
+    gsize decap_len = 0;
+    gsize used = 0;
+    gboolean more = FALSE;
+
+    success = dm_decapsulate_buffer (inbuf, sizeof (inbuf),
+                                     outbuf, sizeof (outbuf),
+                                     &decap_len, &used, &more);
+    g_assert (success);
+    g_assert (decap_len == 214);
+    g_assert (used == 221);
+    g_assert (more == FALSE);
+}
+
diff --git a/libqcdm/tests/test-qcdm-utils.h b/libqcdm/tests/test-qcdm-utils.h
new file mode 100644
index 00000000..767a72ae
--- /dev/null
+++ b/libqcdm/tests/test-qcdm-utils.h
@@ -0,0 +1,24 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * Copyright (C) 2010 Red Hat, Inc.
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TEST_QCDM_UTILS_H
+#define TEST_QCDM_UTILS_H
+
+void test_utils_decapsulate_buffer (void *f, void *data);
+
+#endif  /* TEST_QCDM_UTILS_H */
+
diff --git a/libqcdm/tests/test-qcdm.c b/libqcdm/tests/test-qcdm.c
index 01535cac..d87a2e31 100644
--- a/libqcdm/tests/test-qcdm.c
+++ b/libqcdm/tests/test-qcdm.c
@@ -22,6 +22,7 @@
 #include "test-qcdm-escaping.h"
 #include "test-qcdm-com.h"
 #include "test-qcdm-result.h"
+#include "test-qcdm-utils.h"
 
 typedef struct {
     gpointer com_data;
@@ -82,6 +83,7 @@ int main (int argc, char **argv)
     g_test_suite_add (suite, TESTCASE (test_escape1, NULL));
     g_test_suite_add (suite, TESTCASE (test_escape2, NULL));
     g_test_suite_add (suite, TESTCASE (test_escape_unescape, NULL));
+    g_test_suite_add (suite, TESTCASE (test_utils_decapsulate_buffer, NULL));
     g_test_suite_add (suite, TESTCASE (test_result_string, NULL));
     g_test_suite_add (suite, TESTCASE (test_result_uint32, NULL));
     g_test_suite_add (suite, TESTCASE (test_result_uint8, NULL));