Add tests for record encryption/decryption

This commit adds tests exercising mutually inverse pairs of
record encryption and decryption transformations for the various
transformation types allowed in TLS: Stream, CBC, and AEAD.
This commit is contained in:
Hanno Becker 2018-01-03 14:27:32 +00:00 committed by Manuel Pégourié-Gonnard
parent 92231325a7
commit 611a83b571
5 changed files with 2470 additions and 15 deletions

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@ -262,4 +262,3 @@ void mbedtls_debug_printf_ecdh( const mbedtls_ssl_context *ssl, int level,
#endif #endif
#endif /* debug.h */ #endif /* debug.h */

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@ -913,4 +913,14 @@ int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
} }
#endif #endif
void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform );
int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform,
mbedtls_record *rec,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform,
mbedtls_record *rec );
#endif /* ssl_internal.h */ #endif /* ssl_internal.h */

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@ -1466,11 +1466,11 @@ static void ssl_extract_add_data_from_record( unsigned char* add_data,
add_data[12] = rec->data_len & 0xFF; add_data[12] = rec->data_len & 0xFF;
} }
static int ssl_encrypt_buf( mbedtls_ssl_context *ssl, int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform, mbedtls_ssl_transform *transform,
mbedtls_record *rec, mbedtls_record *rec,
int (*f_rng)(void *, unsigned char *, size_t), int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng ) void *p_rng )
{ {
mbedtls_cipher_mode_t mode; mbedtls_cipher_mode_t mode;
int auth_done = 0; int auth_done = 0;
@ -1479,7 +1479,7 @@ static int ssl_encrypt_buf( mbedtls_ssl_context *ssl,
size_t post_avail; size_t post_avail;
/* The SSL context is only used for debugging purposes! */ /* The SSL context is only used for debugging purposes! */
#if !defined(MBEDTLS_SSL_DEBUG_C) #if !defined(MBEDTLS_DEBUG_C)
((void) ssl); ((void) ssl);
#endif #endif
@ -1858,9 +1858,9 @@ static int ssl_encrypt_buf( mbedtls_ssl_context *ssl,
return( 0 ); return( 0 );
} }
static int ssl_decrypt_buf( mbedtls_ssl_context *ssl, int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform, mbedtls_ssl_transform *transform,
mbedtls_record *rec ) mbedtls_record *rec )
{ {
size_t olen; size_t olen;
mbedtls_cipher_mode_t mode; mbedtls_cipher_mode_t mode;
@ -1871,7 +1871,7 @@ static int ssl_decrypt_buf( mbedtls_ssl_context *ssl,
unsigned char* data; unsigned char* data;
unsigned char add_data[13]; unsigned char add_data[13];
#if !defined(MBEDTLS_SSL_DEBUG_C) #if !defined(MBEDTLS_DEBUG_C)
((void) ssl); ((void) ssl);
#endif #endif
@ -3451,7 +3451,7 @@ int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush )
ssl->conf->transport, rec.ver ); ssl->conf->transport, rec.ver );
rec.type = ssl->out_msgtype; rec.type = ssl->out_msgtype;
if( ( ret = ssl_encrypt_buf( ssl, ssl->transform_out, &rec, if( ( ret = mbedtls_ssl_encrypt_buf( ssl, ssl->transform_out, &rec,
ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 ) ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
{ {
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret ); MBEDTLS_SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret );
@ -4333,7 +4333,8 @@ static int ssl_prepare_record_content( mbedtls_ssl_context *ssl )
mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver, mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
ssl->conf->transport, rec.ver ); ssl->conf->transport, rec.ver );
rec.type = ssl->in_msgtype; rec.type = ssl->in_msgtype;
if( ( ret = ssl_decrypt_buf( ssl, ssl->transform_in, &rec ) ) != 0 ) if( ( ret = mbedtls_ssl_decrypt_buf( ssl, ssl->transform_in,
&rec ) ) != 0 )
{ {
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret ); MBEDTLS_SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret );
return( ret ); return( ret );
@ -6783,7 +6784,7 @@ static void ssl_handshake_params_init( mbedtls_ssl_handshake_params *handshake )
#endif #endif
} }
static void ssl_transform_init( mbedtls_ssl_transform *transform ) void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform )
{ {
memset( transform, 0, sizeof(mbedtls_ssl_transform) ); memset( transform, 0, sizeof(mbedtls_ssl_transform) );
@ -6850,7 +6851,7 @@ static int ssl_handshake_init( mbedtls_ssl_context *ssl )
/* Initialize structures */ /* Initialize structures */
mbedtls_ssl_session_init( ssl->session_negotiate ); mbedtls_ssl_session_init( ssl->session_negotiate );
ssl_transform_init( ssl->transform_negotiate ); mbedtls_ssl_transform_init( ssl->transform_negotiate );
ssl_handshake_params_init( ssl->handshake ); ssl_handshake_params_init( ssl->handshake );
#if defined(MBEDTLS_SSL_PROTO_DTLS) #if defined(MBEDTLS_SSL_PROTO_DTLS)

File diff suppressed because it is too large Load diff

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@ -1,6 +1,231 @@
/* BEGIN_HEADER */ /* BEGIN_HEADER */
#include <mbedtls/ssl.h> #include <mbedtls/ssl.h>
#include <mbedtls/ssl_internal.h> #include <mbedtls/ssl_internal.h>
/*
* Helper function setting up inverse record transformations
* using given cipher, hash, EtM mode, authentication tag length,
* and version.
*/
#define CHK( x ) \
do \
{ \
if( !( x ) ) \
return( 1 ); \
} while( 0 )
static int build_transforms( mbedtls_ssl_transform *t_in,
mbedtls_ssl_transform *t_out,
int cipher_type, int hash_id,
int etm, int tag_mode, int ver )
{
mbedtls_cipher_info_t const *cipher_info;
size_t keylen, maclen, ivlen;
unsigned char *key0, *key1;
unsigned char iv_enc[16], iv_dec[16];
maclen = 0;
/* Pick cipher */
cipher_info = mbedtls_cipher_info_from_type( cipher_type );
CHK( cipher_info != NULL );
CHK( cipher_info->iv_size <= 16 );
CHK( cipher_info->key_bitlen % 8 == 0 );
/* Pick keys */
keylen = cipher_info->key_bitlen / 8;
CHK( ( key0 = malloc( keylen ) ) != NULL );
CHK( ( key1 = malloc( keylen ) ) != NULL );
memset( key0, 0x1, keylen );
memset( key1, 0x2, keylen );
/* Setup cipher contexts */
CHK( mbedtls_cipher_setup( &t_in->cipher_ctx_enc, cipher_info ) == 0 );
CHK( mbedtls_cipher_setup( &t_in->cipher_ctx_dec, cipher_info ) == 0 );
CHK( mbedtls_cipher_setup( &t_out->cipher_ctx_enc, cipher_info ) == 0 );
CHK( mbedtls_cipher_setup( &t_out->cipher_ctx_dec, cipher_info ) == 0 );
#if defined(MBEDTLS_CIPHER_MODE_CBC)
if( cipher_info->mode == MBEDTLS_MODE_CBC )
{
CHK( mbedtls_cipher_set_padding_mode( &t_in->cipher_ctx_enc,
MBEDTLS_PADDING_NONE ) == 0 );
CHK( mbedtls_cipher_set_padding_mode( &t_in->cipher_ctx_dec,
MBEDTLS_PADDING_NONE ) == 0 );
CHK( mbedtls_cipher_set_padding_mode( &t_out->cipher_ctx_enc,
MBEDTLS_PADDING_NONE ) == 0 );
CHK( mbedtls_cipher_set_padding_mode( &t_out->cipher_ctx_dec,
MBEDTLS_PADDING_NONE ) == 0 );
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
CHK( mbedtls_cipher_setkey( &t_in->cipher_ctx_enc, key0,
keylen << 3, MBEDTLS_ENCRYPT ) == 0 );
CHK( mbedtls_cipher_setkey( &t_in->cipher_ctx_dec, key1,
keylen << 3, MBEDTLS_DECRYPT ) == 0 );
CHK( mbedtls_cipher_setkey( &t_out->cipher_ctx_enc, key1,
keylen << 3, MBEDTLS_ENCRYPT ) == 0 );
CHK( mbedtls_cipher_setkey( &t_out->cipher_ctx_dec, key0,
keylen << 3, MBEDTLS_DECRYPT ) == 0 );
free( key0 );
free( key1 );
/* Setup MAC contexts */
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
if( cipher_info->mode == MBEDTLS_MODE_CBC ||
cipher_info->mode == MBEDTLS_MODE_STREAM )
{
mbedtls_md_info_t const *md_info;
unsigned char *md0, *md1;
/* Pick hash */
md_info = mbedtls_md_info_from_type( hash_id );
CHK( md_info != NULL );
/* Pick hash keys */
maclen = mbedtls_md_get_size( md_info );
CHK( ( md0 = malloc( maclen ) ) != NULL );
CHK( ( md1 = malloc( maclen ) ) != NULL );
memset( md0, 0x5, maclen );
memset( md1, 0x6, maclen );
CHK( mbedtls_md_setup( &t_out->md_ctx_enc, md_info, 1 ) == 0 );
CHK( mbedtls_md_setup( &t_out->md_ctx_dec, md_info, 1 ) == 0 );
CHK( mbedtls_md_setup( &t_in->md_ctx_enc, md_info, 1 ) == 0 );
CHK( mbedtls_md_setup( &t_in->md_ctx_dec, md_info, 1 ) == 0 );
if( ver > MBEDTLS_SSL_MINOR_VERSION_0 )
{
CHK( mbedtls_md_hmac_starts( &t_in->md_ctx_enc,
md0, maclen ) == 0 );
CHK( mbedtls_md_hmac_starts( &t_in->md_ctx_dec,
md1, maclen ) == 0 );
CHK( mbedtls_md_hmac_starts( &t_out->md_ctx_enc,
md1, maclen ) == 0 );
CHK( mbedtls_md_hmac_starts( &t_out->md_ctx_dec,
md0, maclen ) == 0 );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
else
{
memcpy( &t_in->mac_enc, md0, maclen );
memcpy( &t_in->mac_dec, md1, maclen );
memcpy( &t_out->mac_enc, md1, maclen );
memcpy( &t_out->mac_dec, md0, maclen );
}
#endif
free( md0 );
free( md1 );
}
#else
((void) hash_id);
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
/* Pick IV's (regardless of whether they
* are being used by the transform). */
ivlen = cipher_info->iv_size;
memset( iv_enc, 0x3, sizeof( iv_enc ) );
memset( iv_dec, 0x4, sizeof( iv_dec ) );
/*
* Setup transforms
*/
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
t_out->encrypt_then_mac = etm;
t_in->encrypt_then_mac = etm;
#else
((void) etm);
#endif
t_out->minor_ver = ver;
t_in->minor_ver = ver;
t_out->ivlen = ivlen;
t_in->ivlen = ivlen;
switch( cipher_info->mode )
{
case MBEDTLS_MODE_GCM:
case MBEDTLS_MODE_CCM:
t_out->fixed_ivlen = 4;
t_in->fixed_ivlen = 4;
t_out->maclen = 0;
t_in->maclen = 0;
switch( tag_mode )
{
case 0: /* Full tag */
t_out->taglen = 16;
t_in->taglen = 16;
break;
case 1: /* Partial tag */
t_out->taglen = 8;
t_in->taglen = 8;
break;
default:
return( 1 );
}
break;
case MBEDTLS_MODE_CHACHAPOLY:
t_out->fixed_ivlen = 12;
t_in->fixed_ivlen = 12;
t_out->maclen = 0;
t_in->maclen = 0;
switch( tag_mode )
{
case 0: /* Full tag */
t_out->taglen = 16;
t_in->taglen = 16;
break;
case 1: /* Partial tag */
t_out->taglen = 8;
t_in->taglen = 8;
break;
default:
return( 1 );
}
break;
case MBEDTLS_MODE_STREAM:
case MBEDTLS_MODE_CBC:
t_out->fixed_ivlen = 0; /* redundant, must be 0 */
t_in->fixed_ivlen = 0; /* redundant, must be 0 */
t_out->taglen = 0;
t_in->taglen = 0;
switch( tag_mode )
{
case 0: /* Full tag */
t_out->maclen = maclen;
t_in->maclen = maclen;
break;
case 1: /* Partial tag */
t_out->maclen = 10;
t_in->maclen = 10;
break;
default:
return( 1 );
}
break;
default:
return( 1 );
break;
}
/* Setup IV's */
memcpy( &t_in->iv_dec, iv_dec, sizeof( iv_dec ) );
memcpy( &t_in->iv_enc, iv_enc, sizeof( iv_enc ) );
memcpy( &t_out->iv_dec, iv_enc, sizeof( iv_enc ) );
memcpy( &t_out->iv_enc, iv_dec, sizeof( iv_dec ) );
return( 0 );
}
/* END_HEADER */ /* END_HEADER */
/* BEGIN_DEPENDENCIES /* BEGIN_DEPENDENCIES
@ -52,3 +277,107 @@ void ssl_set_hostname_twice( char *hostname0, char *hostname1 )
mbedtls_ssl_free( &ssl ); mbedtls_ssl_free( &ssl );
} }
/* END_CASE */ /* END_CASE */
/* BEGIN_CASE */
void ssl_crypt_record( int cipher_type, int hash_id,
int etm, int tag_mode, int ver )
{
/*
* Test several record encryptions and decryptions
* with plenty of space before and after the data
* within the record buffer.
*/
int ret;
int num_records = 16;
mbedtls_ssl_context ssl; /* ONLY for debugging */
mbedtls_ssl_transform t0, t1;
unsigned char *buf;
size_t const buflen = 512;
mbedtls_record rec, rec_backup;
mbedtls_ssl_init( &ssl );
mbedtls_ssl_transform_init( &t0 );
mbedtls_ssl_transform_init( &t1 );
TEST_ASSERT( build_transforms( &t0, &t1, cipher_type, hash_id,
etm, tag_mode, ver ) == 0 );
TEST_ASSERT( ( buf = malloc( buflen ) ) != NULL );
while( num_records-- > 0 )
{
mbedtls_ssl_transform *t_dec, *t_enc;
/* Take turns in who's sending and who's receiving. */
if( num_records % 3 == 0 )
{
t_dec = &t0;
t_enc = &t1;
}
else
{
t_dec = &t1;
t_enc = &t0;
}
/*
* The record header affects the transformation in two ways:
* 1) It determines the AEAD additional data
* 2) The record counter sometimes determines the IV.
*
* Apart from that, the fields don't have influence.
* In particular, it is currently not the responsibility
* of ssl_encrypt/decrypt_buf to check if the transform
* version matches the record version, or that the
* type is sensible.
*/
memset( rec.ctr, num_records, sizeof( rec.ctr ) );
rec.type = 42;
rec.ver[0] = num_records;
rec.ver[1] = num_records;
rec.buf = buf;
rec.buf_len = buflen;
rec.data_offset = 16;
/* Make sure to vary the length to exercise different
* paddings. */
rec.data_len = 1 + num_records;
memset( rec.buf + rec.data_offset, 42, rec.data_len );
/* Make a copy for later comparison */
rec_backup = rec;
/* Encrypt record */
ret = mbedtls_ssl_encrypt_buf( &ssl, t_enc, &rec,
rnd_std_rand, NULL );
TEST_ASSERT( ret == 0 || ret == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
if( ret != 0 )
{
continue;
}
/* Decrypt record with t_dec */
TEST_ASSERT( mbedtls_ssl_decrypt_buf( &ssl, t_dec, &rec ) == 0 );
/* Compare results */
TEST_ASSERT( rec.type == rec_backup.type );
TEST_ASSERT( memcmp( rec.ctr, rec_backup.ctr, 8 ) == 0 );
TEST_ASSERT( rec.ver[0] == rec_backup.ver[0] );
TEST_ASSERT( rec.ver[1] == rec_backup.ver[1] );
TEST_ASSERT( rec.data_len == rec_backup.data_len );
TEST_ASSERT( rec.data_offset == rec_backup.data_offset );
TEST_ASSERT( memcmp( rec.buf + rec.data_offset,
rec_backup.buf + rec_backup.data_offset,
rec.data_len ) == 0 );
}
/* Cleanup */
mbedtls_ssl_free( &ssl );
mbedtls_ssl_transform_free( &t0 );
mbedtls_ssl_transform_free( &t1 );
free( buf );
}
/* END_CASE */