Move constant-time HMAC testing to its own suite

These are very CPU-intensive, so make it easy to skip them. And conversely,
make it easy to run them without the growing body of SSL tests.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2022-11-29 15:42:36 +01:00
parent 3917028ab7
commit 3daa98ed95
4 changed files with 117 additions and 110 deletions

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@ -0,0 +1,15 @@
Constant-flow HMAC: MD5
depends_on:MBEDTLS_MD5_C
ssl_cf_hmac:MBEDTLS_MD_MD5
Constant-flow HMAC: SHA1
depends_on:MBEDTLS_SHA1_C
ssl_cf_hmac:MBEDTLS_MD_SHA1
Constant-flow HMAC: SHA256
depends_on:MBEDTLS_SHA256_C
ssl_cf_hmac:MBEDTLS_MD_SHA256
Constant-flow HMAC: SHA384
depends_on:MBEDTLS_SHA512_C:!MBEDTLS_SHA512_NO_SHA384
ssl_cf_hmac:MBEDTLS_MD_SHA384

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@ -0,0 +1,102 @@
/* BEGIN_HEADER */
#include <mbedtls/constant_time.h>
#include <mbedtls/md.h>
#include <constant_time_internal.h>
#include <test/constant_flow.h>
/* END_HEADER */
/* BEGIN_CASE depends_on:MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC:MBEDTLS_TEST_HOOKS */
void ssl_cf_hmac( int hash )
{
/*
* Test the function mbedtls_ct_hmac() against a reference
* implementation.
*/
mbedtls_md_context_t ctx, ref_ctx;
const mbedtls_md_info_t *md_info;
size_t out_len, block_size;
size_t min_in_len, in_len, max_in_len, i;
/* TLS additional data is 13 bytes (hence the "lucky 13" name) */
unsigned char add_data[13];
unsigned char ref_out[MBEDTLS_MD_MAX_SIZE];
unsigned char *data = NULL;
unsigned char *out = NULL;
unsigned char rec_num = 0;
mbedtls_md_init( &ctx );
mbedtls_md_init( &ref_ctx );
md_info = mbedtls_md_info_from_type( hash );
TEST_ASSERT( md_info != NULL );
out_len = mbedtls_md_get_size( md_info );
TEST_ASSERT( out_len != 0 );
block_size = hash == MBEDTLS_MD_SHA384 ? 128 : 64;
/* Use allocated out buffer to catch overwrites */
ASSERT_ALLOC( out, out_len );
/* Set up contexts with the given hash and a dummy key */
TEST_EQUAL( 0, mbedtls_md_setup( &ctx, md_info, 1 ) );
TEST_EQUAL( 0, mbedtls_md_setup( &ref_ctx, md_info, 1 ) );
memset( ref_out, 42, sizeof( ref_out ) );
TEST_EQUAL( 0, mbedtls_md_hmac_starts( &ctx, ref_out, out_len ) );
TEST_EQUAL( 0, mbedtls_md_hmac_starts( &ref_ctx, ref_out, out_len ) );
memset( ref_out, 0, sizeof( ref_out ) );
/*
* Test all possible lengths up to a point. The difference between
* max_in_len and min_in_len is at most 255, and make sure they both vary
* by at least one block size.
*/
for( max_in_len = 0; max_in_len <= 255 + block_size; max_in_len++ )
{
mbedtls_test_set_step( max_in_len * 10000 );
/* Use allocated in buffer to catch overreads */
ASSERT_ALLOC( data, max_in_len );
min_in_len = max_in_len > 255 ? max_in_len - 255 : 0;
for( in_len = min_in_len; in_len <= max_in_len; in_len++ )
{
mbedtls_test_set_step( max_in_len * 10000 + in_len );
/* Set up dummy data and add_data */
rec_num++;
memset( add_data, rec_num, sizeof( add_data ) );
for( i = 0; i < in_len; i++ )
data[i] = ( i & 0xff ) ^ rec_num;
/* Get the function's result */
TEST_CF_SECRET( &in_len, sizeof( in_len ) );
TEST_EQUAL( 0, mbedtls_ct_hmac( &ctx, add_data, sizeof( add_data ),
data, in_len,
min_in_len, max_in_len,
out ) );
TEST_CF_PUBLIC( &in_len, sizeof( in_len ) );
TEST_CF_PUBLIC( out, out_len );
/* Compute the reference result */
TEST_EQUAL( 0, mbedtls_md_hmac_update( &ref_ctx, add_data,
sizeof( add_data ) ) );
TEST_EQUAL( 0, mbedtls_md_hmac_update( &ref_ctx, data, in_len ) );
TEST_EQUAL( 0, mbedtls_md_hmac_finish( &ref_ctx, ref_out ) );
TEST_EQUAL( 0, mbedtls_md_hmac_reset( &ref_ctx ) );
/* Compare */
ASSERT_COMPARE( out, out_len, ref_out, out_len );
}
mbedtls_free( data );
data = NULL;
}
exit:
mbedtls_md_free( &ref_ctx );
mbedtls_md_free( &ctx );
mbedtls_free( data );
mbedtls_free( out );
}
/* END_CASE */

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@ -10002,22 +10002,6 @@ Session serialization, load buffer size: large ticket, cert
depends_on:MBEDTLS_SSL_SESSION_TICKETS:MBEDTLS_SSL_CLI_C:MBEDTLS_X509_USE_C:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_SHA256_C:MBEDTLS_FS_IO
ssl_serialize_session_load_buf_size:1023:"data_files/server5.crt"
Constant-flow HMAC: MD5
depends_on:MBEDTLS_MD5_C
ssl_cf_hmac:MBEDTLS_MD_MD5
Constant-flow HMAC: SHA1
depends_on:MBEDTLS_SHA1_C
ssl_cf_hmac:MBEDTLS_MD_SHA1
Constant-flow HMAC: SHA256
depends_on:MBEDTLS_SHA256_C
ssl_cf_hmac:MBEDTLS_MD_SHA256
Constant-flow HMAC: SHA384
depends_on:MBEDTLS_SHA512_C:!MBEDTLS_SHA512_NO_SHA384
ssl_cf_hmac:MBEDTLS_MD_SHA384
# these are the numbers we'd get with an empty plaintext and truncated HMAC
Constant-flow memcpy from offset: small
ssl_cf_memcpy_offset:0:5:10

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@ -4467,100 +4467,6 @@ void resize_buffers_renegotiate_mfl( int mfl, int legacy_renegotiation,
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC:MBEDTLS_TEST_HOOKS */
void ssl_cf_hmac( int hash )
{
/*
* Test the function mbedtls_ct_hmac() against a reference
* implementation.
*/
mbedtls_md_context_t ctx, ref_ctx;
const mbedtls_md_info_t *md_info;
size_t out_len, block_size;
size_t min_in_len, in_len, max_in_len, i;
/* TLS additional data is 13 bytes (hence the "lucky 13" name) */
unsigned char add_data[13];
unsigned char ref_out[MBEDTLS_MD_MAX_SIZE];
unsigned char *data = NULL;
unsigned char *out = NULL;
unsigned char rec_num = 0;
mbedtls_md_init( &ctx );
mbedtls_md_init( &ref_ctx );
md_info = mbedtls_md_info_from_type( hash );
TEST_ASSERT( md_info != NULL );
out_len = mbedtls_md_get_size( md_info );
TEST_ASSERT( out_len != 0 );
block_size = hash == MBEDTLS_MD_SHA384 ? 128 : 64;
/* Use allocated out buffer to catch overwrites */
ASSERT_ALLOC( out, out_len );
/* Set up contexts with the given hash and a dummy key */
TEST_EQUAL( 0, mbedtls_md_setup( &ctx, md_info, 1 ) );
TEST_EQUAL( 0, mbedtls_md_setup( &ref_ctx, md_info, 1 ) );
memset( ref_out, 42, sizeof( ref_out ) );
TEST_EQUAL( 0, mbedtls_md_hmac_starts( &ctx, ref_out, out_len ) );
TEST_EQUAL( 0, mbedtls_md_hmac_starts( &ref_ctx, ref_out, out_len ) );
memset( ref_out, 0, sizeof( ref_out ) );
/*
* Test all possible lengths up to a point. The difference between
* max_in_len and min_in_len is at most 255, and make sure they both vary
* by at least one block size.
*/
for( max_in_len = 0; max_in_len <= 255 + block_size; max_in_len++ )
{
mbedtls_test_set_step( max_in_len * 10000 );
/* Use allocated in buffer to catch overreads */
ASSERT_ALLOC( data, max_in_len );
min_in_len = max_in_len > 255 ? max_in_len - 255 : 0;
for( in_len = min_in_len; in_len <= max_in_len; in_len++ )
{
mbedtls_test_set_step( max_in_len * 10000 + in_len );
/* Set up dummy data and add_data */
rec_num++;
memset( add_data, rec_num, sizeof( add_data ) );
for( i = 0; i < in_len; i++ )
data[i] = ( i & 0xff ) ^ rec_num;
/* Get the function's result */
TEST_CF_SECRET( &in_len, sizeof( in_len ) );
TEST_EQUAL( 0, mbedtls_ct_hmac( &ctx, add_data, sizeof( add_data ),
data, in_len,
min_in_len, max_in_len,
out ) );
TEST_CF_PUBLIC( &in_len, sizeof( in_len ) );
TEST_CF_PUBLIC( out, out_len );
/* Compute the reference result */
TEST_EQUAL( 0, mbedtls_md_hmac_update( &ref_ctx, add_data,
sizeof( add_data ) ) );
TEST_EQUAL( 0, mbedtls_md_hmac_update( &ref_ctx, data, in_len ) );
TEST_EQUAL( 0, mbedtls_md_hmac_finish( &ref_ctx, ref_out ) );
TEST_EQUAL( 0, mbedtls_md_hmac_reset( &ref_ctx ) );
/* Compare */
ASSERT_COMPARE( out, out_len, ref_out, out_len );
}
mbedtls_free( data );
data = NULL;
}
exit:
mbedtls_md_free( &ref_ctx );
mbedtls_md_free( &ctx );
mbedtls_free( data );
mbedtls_free( out );
}
/* END_CASE */
/* BEGIN_CASE depends_on:MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC:MBEDTLS_TEST_HOOKS */
void ssl_cf_memcpy_offset( int offset_min, int offset_max, int len )
{