Update iv and len context pointers manually when reallocating buffers
These fields might be shifted accordingly in `ssl_parse_record_header()`
when receiving a connection with CID, so they require a manual update
after calling the generic `mbedtls_ssl_reset_in_out_pointers()`.
This commit also adds a regression test which is run by all.sh.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/ChangeLog.d/bugfix_PR3405 b/ChangeLog.d/bugfix_PR3405
new file mode 100644
index 0000000..73c57c0
--- /dev/null
+++ b/ChangeLog.d/bugfix_PR3405
@@ -0,0 +1,5 @@
+Bugfix
+ * Update iv and len context pointers manually when reallocating buffers
+ using the MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH feature. This caused issues
+ when receiving a connection with CID, when these fields were shifted
+ in ssl_parse_record_header().
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 30c917b..a202bd8 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3686,11 +3686,13 @@
/* If the buffers are too small - reallocate */
{
int modified = 0;
- size_t written_in = 0;
- size_t written_out = 0;
+ size_t written_in = 0, iv_offset_in = 0, len_offset_in = 0;
+ size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
if( ssl->in_buf != NULL )
{
written_in = ssl->in_msg - ssl->in_buf;
+ iv_offset_in = ssl->in_iv - ssl->in_buf;
+ len_offset_in = ssl->in_len - ssl->in_buf;
if( ssl->in_buf_len < MBEDTLS_SSL_IN_BUFFER_LEN )
{
if( resize_buffer( &ssl->in_buf, MBEDTLS_SSL_IN_BUFFER_LEN,
@@ -3709,6 +3711,8 @@
if( ssl->out_buf != NULL )
{
written_out = ssl->out_msg - ssl->out_buf;
+ iv_offset_out = ssl->out_iv - ssl->out_buf;
+ len_offset_out = ssl->out_len - ssl->out_buf;
if( ssl->out_buf_len < MBEDTLS_SSL_OUT_BUFFER_LEN )
{
if( resize_buffer( &ssl->out_buf, MBEDTLS_SSL_OUT_BUFFER_LEN,
@@ -3728,9 +3732,14 @@
/* Update pointers here to avoid doing it twice. */
mbedtls_ssl_reset_in_out_pointers( ssl );
/* Fields below might not be properly updated with record
- * splitting, so they are manually updated here. */
+ * splitting or with CID, so they are manually updated here. */
ssl->out_msg = ssl->out_buf + written_out;
+ ssl->out_len = ssl->out_buf + len_offset_out;
+ ssl->out_iv = ssl->out_buf + iv_offset_out;
+
ssl->in_msg = ssl->in_buf + written_in;
+ ssl->in_len = ssl->in_buf + len_offset_in;
+ ssl->in_iv = ssl->in_buf + iv_offset_in;
}
}
#endif
@@ -5960,14 +5969,15 @@
{
int modified = 0;
uint32_t buf_len = mbedtls_ssl_get_input_buflen( ssl );
- size_t written_in = 0;
- size_t written_out = 0;
+ size_t written_in = 0, iv_offset_in = 0, len_offset_in = 0;
+ size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
if( ssl->in_buf != NULL )
{
written_in = ssl->in_msg - ssl->in_buf;
+ iv_offset_in = ssl->in_iv - ssl->in_buf;
+ len_offset_in = ssl->in_len - ssl->in_buf;
if( ssl->in_buf_len > buf_len && ssl->in_left < buf_len )
{
- written_in = ssl->in_msg - ssl->in_buf;
if( resize_buffer( &ssl->in_buf, buf_len, &ssl->in_buf_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
@@ -5985,6 +5995,8 @@
if(ssl->out_buf != NULL )
{
written_out = ssl->out_msg - ssl->out_buf;
+ iv_offset_out = ssl->out_iv - ssl->out_buf;
+ len_offset_out = ssl->out_len - ssl->out_buf;
if( ssl->out_buf_len > mbedtls_ssl_get_output_buflen( ssl ) &&
ssl->out_left < buf_len )
{
@@ -6004,9 +6016,14 @@
/* Update pointers here to avoid doing it twice. */
mbedtls_ssl_reset_in_out_pointers( ssl );
/* Fields below might not be properly updated with record
- * splitting, so they are manually updated here. */
+ * splitting or with CID, so they are manually updated here. */
ssl->out_msg = ssl->out_buf + written_out;
+ ssl->out_len = ssl->out_buf + len_offset_out;
+ ssl->out_iv = ssl->out_buf + iv_offset_out;
+
ssl->in_msg = ssl->in_buf + written_in;
+ ssl->in_len = ssl->in_buf + len_offset_in;
+ ssl->in_iv = ssl->in_buf + iv_offset_in;
}
}
#endif
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index df3f53b..2c95549 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -2201,6 +2201,32 @@
-c "ignoring unexpected CID" \
-s "ignoring unexpected CID"
+requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
+requires_config_enabled MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
+run_test "Connection ID: Cli+Srv enabled, variable buffer lengths, MFL=512" \
+ "$P_SRV dtls=1 cid=1 cid_val=dead debug_level=2" \
+ "$P_CLI force_ciphersuite="TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" max_frag_len=512 dtls=1 cid=1 cid_val=beef" \
+ 0 \
+ -c "(initial handshake) Peer CID (length 2 Bytes): de ad" \
+ -s "(initial handshake) Peer CID (length 2 Bytes): be ef" \
+ -s "(initial handshake) Use of Connection ID has been negotiated" \
+ -c "(initial handshake) Use of Connection ID has been negotiated" \
+ -s "Reallocating in_buf" \
+ -s "Reallocating out_buf"
+
+requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
+requires_config_enabled MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
+run_test "Connection ID: Cli+Srv enabled, variable buffer lengths, MFL=1024" \
+ "$P_SRV dtls=1 cid=1 cid_val=dead debug_level=2" \
+ "$P_CLI force_ciphersuite="TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" max_frag_len=1024 dtls=1 cid=1 cid_val=beef" \
+ 0 \
+ -c "(initial handshake) Peer CID (length 2 Bytes): de ad" \
+ -s "(initial handshake) Peer CID (length 2 Bytes): be ef" \
+ -s "(initial handshake) Use of Connection ID has been negotiated" \
+ -c "(initial handshake) Use of Connection ID has been negotiated" \
+ -s "Reallocating in_buf" \
+ -s "Reallocating out_buf"
+
# Tests for Encrypt-then-MAC extension
run_test "Encrypt then MAC: default" \