Refactor the variable I/O buffer size feature

Reduce code duplication to simplify the feature and reduce code size.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
This commit is contained in:
Andrzej Kurek 2020-10-21 15:08:44 +02:00
parent a51e1dbe76
commit 4a0637981b

View File

@ -260,6 +260,70 @@ static int resize_buffer( unsigned char **buffer, size_t len_new, size_t *len_ol
return 0;
}
static void handle_buffer_resizing( mbedtls_ssl_context *ssl, int downsizing,
uint32_t in_buf_new_len,
uint32_t out_buf_new_len )
{
int modified = 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( downsizing ?
ssl->in_buf_len > in_buf_new_len && ssl->in_left < in_buf_new_len :
ssl->in_buf_len < in_buf_new_len )
{
if( resize_buffer( &ssl->in_buf, in_buf_new_len, &ssl->in_buf_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %d", in_buf_new_len ) );
modified = 1;
}
}
}
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( downsizing ?
ssl->out_buf_len > out_buf_new_len && ssl->out_left < out_buf_new_len :
ssl->out_buf_len < out_buf_new_len )
{
if( resize_buffer( &ssl->out_buf, out_buf_new_len, &ssl->out_buf_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %d", out_buf_new_len ) );
modified = 1;
}
}
}
if( modified )
{
/* 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 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 /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
/*
@ -3686,64 +3750,9 @@ static int ssl_handshake_init( mbedtls_ssl_context *ssl )
}
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
/* If the buffers are too small - reallocate */
{
int modified = 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,
&ssl->in_buf_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %d", MBEDTLS_SSL_IN_BUFFER_LEN ) );
modified = 1;
}
}
}
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,
&ssl->out_buf_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %d", MBEDTLS_SSL_OUT_BUFFER_LEN ) );
modified = 1;
}
}
}
if( modified )
{
/* 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 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;
}
}
handle_buffer_resizing( ssl, 0, MBEDTLS_SSL_IN_BUFFER_LEN,
MBEDTLS_SSL_OUT_BUFFER_LEN );
#endif
/* All pointers should exist and can be directly freed without issue */
@ -6068,66 +6077,8 @@ void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl )
* processes datagrams and the fact that a datagram is allowed to have
* several records in it, it is possible that the I/O buffers are not
* empty at this stage */
{
int modified = 0;
uint32_t buf_len = mbedtls_ssl_get_input_buflen( ssl );
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 )
{
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" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating in_buf to %d", buf_len ) );
modified = 1;
}
}
}
buf_len = mbedtls_ssl_get_output_buflen( ssl );
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 )
{
if( resize_buffer( &ssl->out_buf, buf_len, &ssl->out_buf_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "output buffer resizing failed - out of memory" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Reallocating out_buf to %d", buf_len ) );
modified = 1;
}
}
}
if( modified )
{
/* 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 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;
}
}
handle_buffer_resizing( ssl, 1, mbedtls_ssl_get_input_buflen( ssl ),
mbedtls_ssl_get_output_buflen( ssl ) );
#endif
}