Add I/O buffer resizing in handshake init and free

Add a conditional buffer resizing feature. Introduce tests exercising
it in various setups (serialization, renegotiation, mfl manipulations).
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
This commit is contained in:
Andrzej Kurek 2020-03-03 10:39:58 -05:00
parent aad82f9bbb
commit 0afa2a1b65
No known key found for this signature in database
GPG key ID: 89A90840DC388527
4 changed files with 309 additions and 0 deletions

View file

@ -256,6 +256,32 @@
+ ( MBEDTLS_SSL_CID_OUT_LEN_MAX ) ) + ( MBEDTLS_SSL_CID_OUT_LEN_MAX ) )
#endif #endif
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
static inline uint32_t mbedtls_ssl_get_output_buflen( const mbedtls_ssl_context *ctx )
{
#if defined (MBEDTLS_SSL_DTLS_CONNECTION_ID)
return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+ MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD
+ MBEDTLS_SSL_CID_OUT_LEN_MAX;
#else
return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+ MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD;
#endif
}
static inline uint32_t mbedtls_ssl_get_input_buflen( const mbedtls_ssl_context *ctx )
{
#if defined (MBEDTLS_SSL_DTLS_CONNECTION_ID)
return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+ MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD
+ MBEDTLS_SSL_CID_IN_LEN_MAX;
#else
return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+ MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD;
#endif
}
#endif
#ifdef MBEDTLS_ZLIB_SUPPORT #ifdef MBEDTLS_ZLIB_SUPPORT
/* Compression buffer holds both IN and OUT buffers, so should be size of the larger */ /* Compression buffer holds both IN and OUT buffers, so should be size of the larger */
#define MBEDTLS_SSL_COMPRESS_BUFFER_LEN ( \ #define MBEDTLS_SSL_COMPRESS_BUFFER_LEN ( \

View file

@ -245,6 +245,29 @@ int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
return( 0 ); return( 0 );
} }
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
static int resize_buffer( unsigned char **buffer, size_t len_new, size_t *len_old )
{
unsigned char* resized_buffer = mbedtls_calloc( 1, len_new );
if( resized_buffer == NULL )
return -1;
/* We want to copy len_new bytes when downsizing the buffer, and
* len_old bytes when upsizing, so we choose the smaller of two sizes,
* to fit one buffer into another. Size checks, ensuring that no data is
* lost, are done outside of this function. */
memcpy( resized_buffer, *buffer,
( len_new < *len_old ) ? len_new : *len_old );
mbedtls_platform_zeroize( *buffer, *len_old );
mbedtls_free( *buffer );
*buffer = resized_buffer;
*len_old = len_new;
return 0;
}
#endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
/* /*
* Key material generation * Key material generation
*/ */
@ -3643,6 +3666,43 @@ static int ssl_handshake_init( mbedtls_ssl_context *ssl )
{ {
ssl->handshake = mbedtls_calloc( 1, sizeof(mbedtls_ssl_handshake_params) ); ssl->handshake = mbedtls_calloc( 1, sizeof(mbedtls_ssl_handshake_params) );
} }
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
/* If the buffers are too small - reallocate */
{
int modified = 0;
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_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 );
}
}
#endif
/* All pointers should exist and can be directly freed without issue */ /* All pointers should exist and can be directly freed without issue */
if( ssl->handshake == NULL || if( ssl->handshake == NULL ||
@ -5818,6 +5878,60 @@ void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl )
mbedtls_platform_zeroize( handshake, mbedtls_platform_zeroize( handshake,
sizeof( mbedtls_ssl_handshake_params ) ); sizeof( mbedtls_ssl_handshake_params ) );
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
/* If the buffers are too big - reallocate. Because of the way Mbed TLS
* 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;
size_t written_out = 0;
if( ssl->in_buf != NULL &&
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" ) );
}
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 &&
ssl->out_buf_len > mbedtls_ssl_get_output_buflen( ssl ) &&
ssl->out_left < buf_len )
{
written_out = ssl->out_msg - ssl->out_buf;
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, so they are manually updated here. */
ssl->out_msg = ssl->out_buf + written_out;
ssl->in_msg = ssl->in_buf + written_in;
}
}
#endif
} }
void mbedtls_ssl_session_free( mbedtls_ssl_session *session ) void mbedtls_ssl_session_free( mbedtls_ssl_session *session )
@ -6499,12 +6613,14 @@ void mbedtls_ssl_free( mbedtls_ssl_context *ssl )
{ {
mbedtls_platform_zeroize( ssl->out_buf, out_buf_len ); mbedtls_platform_zeroize( ssl->out_buf, out_buf_len );
mbedtls_free( ssl->out_buf ); mbedtls_free( ssl->out_buf );
ssl->out_buf = NULL;
} }
if( ssl->in_buf != NULL ) if( ssl->in_buf != NULL )
{ {
mbedtls_platform_zeroize( ssl->in_buf, in_buf_len ); mbedtls_platform_zeroize( ssl->in_buf, in_buf_len );
mbedtls_free( ssl->in_buf ); mbedtls_free( ssl->in_buf );
ssl->in_buf = NULL;
} }
#if defined(MBEDTLS_ZLIB_SUPPORT) #if defined(MBEDTLS_ZLIB_SUPPORT)

View file

@ -368,6 +368,54 @@ renegotiation:MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION
DTLS renegotiation: legacy break handshake DTLS renegotiation: legacy break handshake
renegotiation:MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE renegotiation:MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE
DTLS serialization with MFL=512
resize_buffers_serialize_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_512
DTLS serialization with MFL=1024
resize_buffers_serialize_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_1024
DTLS serialization with MFL=2048
resize_buffers_serialize_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_2048
DTLS serialization with MFL=4096
resize_buffers_serialize_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_4096
DTLS no legacy renegotiation with MFL=512
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_512:MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION
DTLS no legacy renegotiation with MFL=1024
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_1024:MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION
DTLS no legacy renegotiation with MFL=2048
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_2048:MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION
DTLS no legacy renegotiation with MFL=4096
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_4096:MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION
DTLS legacy allow renegotiation with MFL=512
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_512:MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION
DTLS legacy allow renegotiation with MFL=1024
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_1024:MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION
DTLS legacy allow renegotiation with MFL=2048
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_2048:MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION
DTLS legacy allow renegotiation with MFL=4096
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_4096:MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION
DTLS legacy break handshake renegotiation with MFL=512
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_512:MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE
DTLS legacy break handshake renegotiation with MFL=1024
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_1024:MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE
DTLS legacy break handshake renegotiation with MFL=2048
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_2048:MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE
DTLS legacy break handshake renegotiation with MFL=4096
resize_buffers_renegotiate_mfl:MBEDTLS_SSL_MAX_FRAG_LEN_4096:MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE
SSL DTLS replay: initial state, seqnum 0 SSL DTLS replay: initial state, seqnum 0
ssl_dtls_replay:"":"000000000000":0 ssl_dtls_replay:"":"000000000000":0

View file

@ -55,6 +55,7 @@ typedef struct handshake_test_options
void *cli_log_obj; void *cli_log_obj;
void (*srv_log_fun)(void *, int, const char *, int, const char *); void (*srv_log_fun)(void *, int, const char *, int, const char *);
void (*cli_log_fun)(void *, int, const char *, int, const char *); void (*cli_log_fun)(void *, int, const char *, int, const char *);
int resize_buffers;
} handshake_test_options; } handshake_test_options;
void init_handshake_options( handshake_test_options *opts ) void init_handshake_options( handshake_test_options *opts )
@ -77,6 +78,7 @@ void init_handshake_options( handshake_test_options *opts )
opts->srv_log_obj = NULL; opts->srv_log_obj = NULL;
opts->srv_log_fun = NULL; opts->srv_log_fun = NULL;
opts->cli_log_fun = NULL; opts->cli_log_fun = NULL;
opts->resize_buffers = 1;
} }
/* /*
* Buffer structure for custom I/O callbacks. * Buffer structure for custom I/O callbacks.
@ -1767,6 +1769,17 @@ void perform_handshake( handshake_test_options* options )
&(server.socket), &(server.socket),
BUFFSIZE ) == 0 ); BUFFSIZE ) == 0 );
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
if( options->resize_buffers != 0 )
{
/* Ensure that the buffer sizes are appropriate before resizes */
TEST_ASSERT( client.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN );
TEST_ASSERT( client.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN );
TEST_ASSERT( server.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN );
TEST_ASSERT( server.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN );
}
#endif
TEST_ASSERT( mbedtls_move_handshake_to_state( &(client.ssl), TEST_ASSERT( mbedtls_move_handshake_to_state( &(client.ssl),
&(server.ssl), &(server.ssl),
MBEDTLS_SSL_HANDSHAKE_OVER ) MBEDTLS_SSL_HANDSHAKE_OVER )
@ -1774,6 +1787,31 @@ void perform_handshake( handshake_test_options* options )
TEST_ASSERT( client.ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER ); TEST_ASSERT( client.ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER );
TEST_ASSERT( server.ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER ); TEST_ASSERT( server.ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER );
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
if( options->resize_buffers != 0 )
{
/* Note - the case below will have to updated, since due to a 1n-1
* split against BEAST the fragment count is different
* than expected when preparing the fragment counting code. */
if( options->version != MBEDTLS_SSL_MINOR_VERSION_0 &&
options->version != MBEDTLS_SSL_MINOR_VERSION_1 )
{
/* A server, when using DTLS, might delay a buffer resize to happen
* after it receives a message, so we force it. */
TEST_ASSERT( exchange_data( &(client.ssl), &(server.ssl) ) == 0 );
TEST_ASSERT( client.ssl.out_buf_len ==
mbedtls_ssl_get_output_buflen( &client.ssl ) );
TEST_ASSERT( client.ssl.in_buf_len ==
mbedtls_ssl_get_input_buflen( &client.ssl ) );
TEST_ASSERT( server.ssl.out_buf_len ==
mbedtls_ssl_get_output_buflen( &server.ssl ) );
TEST_ASSERT( server.ssl.in_buf_len ==
mbedtls_ssl_get_input_buflen( &server.ssl ) );
}
}
#endif
if( options->cli_msg_len != 0 || options->srv_msg_len != 0 ) if( options->cli_msg_len != 0 || options->srv_msg_len != 0 )
{ {
/* Start data exchanging test */ /* Start data exchanging test */
@ -1813,10 +1851,28 @@ void perform_handshake( handshake_test_options* options )
mbedtls_ssl_set_timer_cb( &server.ssl, &timer_server, mbedtls_ssl_set_timer_cb( &server.ssl, &timer_server,
mbedtls_timing_set_delay, mbedtls_timing_set_delay,
mbedtls_timing_get_delay ); mbedtls_timing_get_delay );
#endif
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
if( options->resize_buffers != 0 )
{
/* Ensure that the buffer sizes are appropriate before resizes */
TEST_ASSERT( server.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN );
TEST_ASSERT( server.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN );
}
#endif #endif
TEST_ASSERT( mbedtls_ssl_context_load( &( server.ssl ), context_buf, TEST_ASSERT( mbedtls_ssl_context_load( &( server.ssl ), context_buf,
context_buf_len ) == 0 ); context_buf_len ) == 0 );
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
/* Validate buffer sizes after context deserialization */
if( options->resize_buffers != 0 )
{
TEST_ASSERT( server.ssl.out_buf_len ==
mbedtls_ssl_get_output_buflen( &server.ssl ) );
TEST_ASSERT( server.ssl.in_buf_len ==
mbedtls_ssl_get_input_buflen( &server.ssl ) );
}
#endif
/* Retest writing/reading */ /* Retest writing/reading */
if( options->cli_msg_len != 0 || options->srv_msg_len != 0 ) if( options->cli_msg_len != 0 || options->srv_msg_len != 0 )
{ {
@ -1830,6 +1886,7 @@ void perform_handshake( handshake_test_options* options )
} }
} }
#endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */ #endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */
#if defined(MBEDTLS_SSL_RENEGOTIATION) #if defined(MBEDTLS_SSL_RENEGOTIATION)
if( options->renegotiate ) if( options->renegotiate )
{ {
@ -1859,6 +1916,14 @@ void perform_handshake( handshake_test_options* options )
* function will return waiting error on the socket. All rest of * function will return waiting error on the socket. All rest of
* renegotiation should happen during data exchanging */ * renegotiation should happen during data exchanging */
ret = mbedtls_ssl_renegotiate( &(client.ssl) ); ret = mbedtls_ssl_renegotiate( &(client.ssl) );
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
if( options->resize_buffers != 0 )
{
/* Ensure that the buffer sizes are appropriate before resizes */
TEST_ASSERT( client.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN );
TEST_ASSERT( client.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN );
}
#endif
TEST_ASSERT( ret == 0 || TEST_ASSERT( ret == 0 ||
ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_READ ||
ret == MBEDTLS_ERR_SSL_WANT_WRITE ); ret == MBEDTLS_ERR_SSL_WANT_WRITE );
@ -1872,6 +1937,20 @@ void perform_handshake( handshake_test_options* options )
MBEDTLS_SSL_RENEGOTIATION_DONE ); MBEDTLS_SSL_RENEGOTIATION_DONE );
TEST_ASSERT( client.ssl.renego_status == TEST_ASSERT( client.ssl.renego_status ==
MBEDTLS_SSL_RENEGOTIATION_DONE ); MBEDTLS_SSL_RENEGOTIATION_DONE );
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
/* Validate buffer sizes after renegotiation */
if( options->resize_buffers != 0 )
{
TEST_ASSERT( client.ssl.out_buf_len ==
mbedtls_ssl_get_output_buflen( &client.ssl ) );
TEST_ASSERT( client.ssl.in_buf_len ==
mbedtls_ssl_get_input_buflen( &client.ssl ) );
TEST_ASSERT( server.ssl.out_buf_len ==
mbedtls_ssl_get_output_buflen( &server.ssl ) );
TEST_ASSERT( server.ssl.in_buf_len ==
mbedtls_ssl_get_input_buflen( &server.ssl ) );
}
#endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
} }
#endif /* MBEDTLS_SSL_RENEGOTIATION */ #endif /* MBEDTLS_SSL_RENEGOTIATION */
@ -3797,3 +3876,43 @@ void renegotiation( int legacy_renegotiation )
goto exit; goto exit;
} }
/* END_CASE */ /* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_PARSE_C:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED */
void resize_buffers( int mfl, int renegotiation, int legacy_renegotiation,
int serialize, int dtls )
{
handshake_test_options options;
init_handshake_options( &options );
options.mfl = mfl;
options.renegotiate = renegotiation;
options.legacy_renegotiation = legacy_renegotiation;
options.serialize = serialize;
options.dtls = dtls;
options.resize_buffers = 1;
perform_handshake( &options );
/* The goto below is used to avoid an "unused label" warning.*/
goto exit;
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_PARSE_C:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH:MBEDTLS_SSL_CONTEXT_SERIALIZATION:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SSL_PROTO_DTLS */
void resize_buffers_serialize_mfl( int mfl )
{
test_resize_buffers( mfl, 0, MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION, 1, 1 );
/* The goto below is used to avoid an "unused label" warning.*/
goto exit;
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_PARSE_C:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH:MBEDTLS_SSL_RENEGOTIATION:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED */
void resize_buffers_renegotiate_mfl( int mfl, int legacy_renegotiation )
{
test_resize_buffers( mfl, 1, legacy_renegotiation, 0, 1 );
/* The goto below is used to avoid an "unused label" warning.*/
goto exit;
}
/* END_CASE */