Add mbedtls_test_buffer to SSL unit tests

In a unit test we want to avoid accessing the network. To test the
handshake in the unit test suite we need to implement a connection
between the server and the client. This ring buffer implementation will
serve as the said connection.
This commit is contained in:
Janos Follath 2019-11-26 11:11:15 +00:00
parent 512fe9673f
commit 6264e66ba4
2 changed files with 337 additions and 0 deletions

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@ -1,3 +1,36 @@
Test calback buffer sanity
test_callback_buffer_sanity:
Callback buffer test: Exercise simple write/read
test_callback_buffer:50:25:25:25:25:0:0:0:0
Callback buffer test: Filling up the buffer
test_callback_buffer:50:50:50:50:50:0:0:0:0
Callback buffer test: Filling up the buffer in two steps
test_callback_buffer:50:20:20:0:0:30:30:50:50
Callback buffer test: Reading out the buffer in two steps
test_callback_buffer:50:50:50:30:30:0:0:20:20
Callback buffer test: Data wraps in buffer
test_callback_buffer:50:45:45:10:10:10:10:45:45
Callback buffer test: Data starts at the end
test_callback_buffer:50:50:50:49:49:10:10:11:11
Callback buffer test: Can write less than requested
test_callback_buffer:50:75:50:30:30:25:25:45:45
Callback buffer test: Can read less than requested
test_callback_buffer:50:25:25:30:25:5:5:5:5
Callback buffer test: Writing to full buffer
test_callback_buffer:50:50:50:0:0:10:0:60:50
Callback buffer test: Reading from empty buffer
test_callback_buffer:50:0:0:10:0:0:0:0:0
SSL DTLS replay: initial state, seqnum 0
ssl_dtls_replay:"":"000000000000":0

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@ -2,6 +2,141 @@
#include <mbedtls/ssl.h>
#include <mbedtls/ssl_internal.h>
/*
* Buffer structure for custom I/O callbacks.
*/
typedef struct mbedtls_test_buffer
{
size_t start;
size_t content_length;
size_t capacity;
unsigned char *buffer;
} mbedtls_test_buffer;
/*
* Initialises \p buf. After calling this function it is safe to call
* `mbedtls_test_buffer_free()` on \p buf.
*/
void mbedtls_test_buffer_init( mbedtls_test_buffer *buf )
{
memset( buf, 0, sizeof( *buf ) );
}
/*
* Sets up \p buf. After calling this function it is safe to call
* `mbedtls_test_buffer_put()` and `mbedtls_test_buffer_get()` on \p buf.
*/
int mbedtls_test_buffer_setup( mbedtls_test_buffer *buf, size_t capacity )
{
buf->buffer = (unsigned char*) mbedtls_calloc( capacity,
sizeof(unsigned char) );
if( NULL == buf->buffer )
return MBEDTLS_ERR_SSL_ALLOC_FAILED;
buf->capacity = capacity;
return 0;
}
void mbedtls_test_buffer_free( mbedtls_test_buffer *buf )
{
if( buf->buffer != NULL )
mbedtls_free( buf->buffer );
memset( buf, 0, sizeof( *buf ) );
}
/*
* Puts \p input_len bytes from the \p input buffer into the ring buffer \p buf.
*
* \p buf must have been initialized and set up by calling
* `mbedtls_test_buffer_init()` and `mbedtls_test_buffer_setup()`.
*
* \retval \p input_len, if the data fits.
* \retval 0 <= value < \p input_len, if the data does not fit.
* \retval -1, if \p buf is NULL, it hasn't been set up or \p input_len is not
* zero and \p input is NULL.
*/
int mbedtls_test_buffer_put( mbedtls_test_buffer *buf,
const unsigned char* input, size_t input_len )
{
size_t overflow = 0;
if( ( buf == NULL ) || ( buf->buffer == NULL ) )
return -1;
/* Reduce input_len to a number that fits in the buffer. */
if ( ( buf->content_length + input_len ) > buf->capacity )
{
input_len = buf->capacity - buf->content_length;
}
if( input == NULL )
{
return ( input_len == 0 ) ? 0 : -1;
}
/* Calculate the number of bytes that need to be placed at lower memory
* address */
if( buf->start + buf->content_length + input_len
> buf->capacity )
{
overflow = ( buf->start + buf->content_length + input_len )
% buf->capacity;
}
memcpy( buf->buffer + buf->start + buf->content_length, input,
input_len - overflow );
memcpy( buf->buffer, input + input_len - overflow, overflow );
buf->content_length += input_len;
return input_len;
}
/*
* Gets \p output_len bytes from the \p output buffer into the ring buffer
* \p buf.
*
* \p buf must have been initialized and set up by calling
* `mbedtls_test_buffer_init()` and `mbedtls_test_buffer_setup()`.
*
* \retval \p output_len, if the data is available.
* \retval 0 <= value < \p output_len, if the data is not available.
* \retval -1, if \buf is NULL, it hasn't been set up or \p output_len is not
* zero and \p output is NULL
*/
int mbedtls_test_buffer_get( mbedtls_test_buffer *buf,
unsigned char* output, size_t output_len )
{
size_t overflow = 0;
if( ( buf == NULL ) || ( buf->buffer == NULL ) )
return -1;
if( output == NULL )
{
return ( output_len == 0 ) ? 0 : -1;
}
if( buf->content_length < output_len )
output_len = buf->content_length;
/* Calculate the number of bytes that need to be drawn from lower memory
* address */
if( buf->start + output_len > buf->capacity )
{
overflow = ( buf->start + output_len ) % buf->capacity;
}
memcpy( output, buf->buffer + buf->start, output_len - overflow );
memcpy( output + output_len - overflow, buf->buffer, overflow );
buf->content_length -= output_len;
buf->start = ( buf->start + output_len ) % buf->capacity;
return output_len;
}
/*
* Helper function setting up inverse record transformations
* using given cipher, hash, EtM mode, authentication tag length,
@ -361,6 +496,175 @@ static int ssl_populate_session( mbedtls_ssl_session *session,
* END_DEPENDENCIES
*/
/* BEGIN_CASE */
void test_callback_buffer_sanity()
{
enum { MSGLEN = 10 };
mbedtls_test_buffer buf;
unsigned char input[MSGLEN];
unsigned char output[MSGLEN];
memset( input, 0, sizeof(input) );
/* Make sure calling put and get on NULL buffer results in error. */
TEST_ASSERT( mbedtls_test_buffer_put( NULL, input, sizeof( input ) )
== -1 );
TEST_ASSERT( mbedtls_test_buffer_get( NULL, output, sizeof( output ) )
== -1 );
TEST_ASSERT( mbedtls_test_buffer_put( NULL, NULL, sizeof( input ) ) == -1 );
TEST_ASSERT( mbedtls_test_buffer_get( NULL, NULL, sizeof( output ) )
== -1 );
TEST_ASSERT( mbedtls_test_buffer_put( NULL, NULL, 0 ) == -1 );
TEST_ASSERT( mbedtls_test_buffer_get( NULL, NULL, 0 ) == -1 );
/* Make sure calling put and get on a buffer that hasn't been set up results
* in eror. */
mbedtls_test_buffer_init( &buf );
TEST_ASSERT( mbedtls_test_buffer_put( &buf, input, sizeof( input ) ) == -1 );
TEST_ASSERT( mbedtls_test_buffer_get( &buf, output, sizeof( output ) )
== -1 );
TEST_ASSERT( mbedtls_test_buffer_put( &buf, NULL, sizeof( input ) ) == -1 );
TEST_ASSERT( mbedtls_test_buffer_get( &buf, NULL, sizeof( output ) )
== -1 );
TEST_ASSERT( mbedtls_test_buffer_put( &buf, NULL, 0 ) == -1 );
TEST_ASSERT( mbedtls_test_buffer_get( &buf, NULL, 0 ) == -1 );
/* Make sure calling put end get on NULL input and output only results in
* error if the length is not zero. */
TEST_ASSERT( mbedtls_test_buffer_setup( &buf, sizeof( input ) ) == 0 );
TEST_ASSERT( mbedtls_test_buffer_put( &buf, NULL, sizeof( input ) ) == -1 );
TEST_ASSERT( mbedtls_test_buffer_get( &buf, NULL, sizeof( output ) )
== -1 );
TEST_ASSERT( mbedtls_test_buffer_put( &buf, NULL, 0 ) == 0 );
TEST_ASSERT( mbedtls_test_buffer_get( &buf, NULL, 0 ) == 0 );
exit:
mbedtls_test_buffer_free( &buf );
}
/* END_CASE */
/*
* Test if the implementation of `mbedtls_test_buffer` related functions is
* correct and works as expected.
*
* That is
* - If we try to put in \p put1 bytes then we can put in \p put1_ret bytes.
* - Afterwards if we try to get \p get1 bytes then we can get \get1_ret bytes.
* - Next, if we try to put in \p put1 bytes then we can put in \p put1_ret
* bytes.
* - Afterwards if we try to get \p get1 bytes then we can get \get1_ret bytes.
* - All of the bytes we got match the bytes we put in in a FIFO manner.
*/
/* BEGIN_CASE */
void test_callback_buffer( int size, int put1, int put1_ret,
int get1, int get1_ret, int put2, int put2_ret,
int get2, int get2_ret )
{
enum { ROUNDS = 2 };
size_t put[ROUNDS];
int put_ret[ROUNDS];
size_t get[ROUNDS];
int get_ret[ROUNDS];
mbedtls_test_buffer buf;
unsigned char* input = NULL;
size_t input_len;
unsigned char* output = NULL;
size_t output_len;
size_t i, written, read;
int j;
mbedtls_test_buffer_init( &buf );
TEST_ASSERT( mbedtls_test_buffer_setup( &buf, size ) == 0 );
/* Check the sanity of input parameters and initialise local variables. That
* is, ensure that the amount of data is not negative and that we are not
* expecting more to put or get than we actually asked for. */
TEST_ASSERT( put1 >= 0 );
put[0] = put1;
put_ret[0] = put1_ret;
TEST_ASSERT( put1_ret <= put1 );
TEST_ASSERT( put2 >= 0 );
put[1] = put2;
put_ret[1] = put2_ret;
TEST_ASSERT( put2_ret <= put2 );
TEST_ASSERT( get1 >= 0 );
get[0] = get1;
get_ret[0] = get1_ret;
TEST_ASSERT( get1_ret <= get1 );
TEST_ASSERT( get2 >= 0 );
get[1] = get2;
get_ret[1] = get2_ret;
TEST_ASSERT( get2_ret <= get2 );
input_len = 0;
/* Calculate actual input and output lengths */
for( j = 0; j < ROUNDS; j++ )
{
if( put_ret[j] > 0 )
{
input_len += put_ret[j];
}
}
/* In order to always have a valid pointer we always allocate at least 1
* byte. */
if( input_len == 0 )
input_len = 1;
ASSERT_ALLOC( input, input_len );
output_len = 0;
for( j = 0; j < ROUNDS; j++ )
{
if( get_ret[j] > 0 )
{
output_len += get_ret[j];
}
}
TEST_ASSERT( output_len <= input_len );
/* In order to always have a valid pointer we always allocate at least 1
* byte. */
if( output_len == 0 )
output_len = 1;
ASSERT_ALLOC( output, output_len );
/* Fill up the buffer with structured data so that unwanted changes
* can be detected */
for( i = 0; i < input_len; i++ )
{
input[i] = i & 0xFF;
}
written = read = 0;
for( j = 0; j < ROUNDS; j++ )
{
TEST_ASSERT( put_ret[j] == mbedtls_test_buffer_put( &buf,
input + written, put[j] ) );
written += put_ret[j];
TEST_ASSERT( get_ret[j] == mbedtls_test_buffer_get( &buf,
output + read, get[j] ) );
read += get_ret[j];
TEST_ASSERT( read <= written );
if( get_ret[j] > 0 )
{
TEST_ASSERT( memcmp( output + read - get_ret[j],
input + read - get_ret[j], get_ret[j] )
== 0 );
}
}
exit:
mbedtls_free( input );
mbedtls_free( output );
mbedtls_test_buffer_free( &buf );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_SSL_DTLS_ANTI_REPLAY */
void ssl_dtls_replay( data_t * prevs, data_t * new, int ret )
{