lib/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-07-29 11:41:15 +03:00
Code Activity

Catch failures of AES or DES operations

Browse Source 
Declare all AES and DES functions that return int as needing to have
their result checked, and do check the result in our code.

A DES or AES block operation can fail in alternative implementations of
mbedtls_internal_aes_encrypt() (under MBEDTLS_AES_ENCRYPT_ALT),
mbedtls_internal_aes_decrypt() (under MBEDTLS_AES_DECRYPT_ALT),
mbedtls_des_crypt_ecb() (under MBEDTLS_DES_CRYPT_ECB_ALT),
mbedtls_des3_crypt_ecb() (under MBEDTLS_DES3_CRYPT_ECB_ALT).
A failure can happen if the accelerator peripheral is in a bad state.
Several block modes were not catching the error.

This commit does the following code changes, grouped together to avoid
having an intermediate commit where the build fails:

* Add MBEDTLS_CHECK_RETURN to all functions returning int in aes.h and des.h.
* Fix all places where this causes a GCC warning, indicating that our code
  was not properly checking the result of an AES operation:
    * In library code: on failure, goto exit and return ret.
    * In pkey programs: goto exit.
    * In the benchmark program: exit (not ideal since there's no error
      message, but it's what the code currently does for failures).
    * In test code: TEST_ASSERT.
* Changelog entry.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine
2021-07-07 21:08:28 +02:00
parent 7b8571fcb5
commit 377a310da4
10 changed files with 164 additions and 60 deletions
Download Patch File Download Diff File Expand all files Collapse all files

75
library/des.c
View File

@ -28,6 +28,7 @@
#if defined(MBEDTLS_DES_C)
#include "mbedtls/des.h"
#include "mbedtls/error.h"
#include "mbedtls/platform_util.h"
#include <string.h>
@ -665,6 +666,7 @@ int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
unsigned char *output )
{
int i;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char temp[8];
if( length % 8 )
@ -677,7 +679,9 @@ int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( input[i] ^ iv[i] );
mbedtls_des_crypt_ecb( ctx, output, output );
ret = mbedtls_des_crypt_ecb( ctx, output, output );
if( ret != 0 )
goto exit;
memcpy( iv, output, 8 );
input += 8;
@ -690,7 +694,9 @@ int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
while( length > 0 )
{
memcpy( temp, input, 8 );
mbedtls_des_crypt_ecb( ctx, input, output );
ret = mbedtls_des_crypt_ecb( ctx, input, output );
if( ret != 0 )
goto exit;
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( output[i] ^ iv[i] );
@ -702,8 +708,10 @@ int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
length -= 8;
}
}
ret = 0;
return( 0 );
exit:
return( ret );
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
@ -764,6 +772,7 @@ int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
unsigned char *output )
{
int i;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char temp[8];
if( length % 8 )
@ -776,7 +785,9 @@ int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( input[i] ^ iv[i] );
mbedtls_des3_crypt_ecb( ctx, output, output );
ret = mbedtls_des3_crypt_ecb( ctx, output, output );
if( ret != 0 )
goto exit;
memcpy( iv, output, 8 );
input += 8;
@ -789,7 +800,9 @@ int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
while( length > 0 )
{
memcpy( temp, input, 8 );
mbedtls_des3_crypt_ecb( ctx, input, output );
ret = mbedtls_des3_crypt_ecb( ctx, input, output );
if( ret != 0 )
goto exit;
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( output[i] ^ iv[i] );
@ -801,8 +814,10 @@ int mbedtls_des3_crypt_cbc( mbedtls_des3_context *ctx,
length -= 8;
}
}
ret = 0;
return( 0 );
exit:
return( ret );
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
@ -895,39 +910,43 @@ int mbedtls_des_self_test( int verbose )
switch( i )
{
case 0:
mbedtls_des_setkey_dec( &ctx, des3_test_keys );
ret = mbedtls_des_setkey_dec( &ctx, des3_test_keys );
break;
case 1:
mbedtls_des_setkey_enc( &ctx, des3_test_keys );
ret = mbedtls_des_setkey_enc( &ctx, des3_test_keys );
break;
case 2:
mbedtls_des3_set2key_dec( &ctx3, des3_test_keys );
ret = mbedtls_des3_set2key_dec( &ctx3, des3_test_keys );
break;
case 3:
mbedtls_des3_set2key_enc( &ctx3, des3_test_keys );
ret = mbedtls_des3_set2key_enc( &ctx3, des3_test_keys );
break;
case 4:
mbedtls_des3_set3key_dec( &ctx3, des3_test_keys );
ret = mbedtls_des3_set3key_dec( &ctx3, des3_test_keys );
break;
case 5:
mbedtls_des3_set3key_enc( &ctx3, des3_test_keys );
ret = mbedtls_des3_set3key_enc( &ctx3, des3_test_keys );
break;
default:
return( 1 );
}
if( ret != 0 )
goto exit;
for( j = 0; j < 100; j++ )
{
if( u == 0 )
mbedtls_des_crypt_ecb( &ctx, buf, buf );
ret = mbedtls_des_crypt_ecb( &ctx, buf, buf );
else
mbedtls_des3_crypt_ecb( &ctx3, buf, buf );
ret = mbedtls_des3_crypt_ecb( &ctx3, buf, buf );
if( ret != 0 )
goto exit;
}
if( ( v == MBEDTLS_DES_DECRYPT &&
@ -970,41 +989,45 @@ int mbedtls_des_self_test( int verbose )
switch( i )
{
case 0:
mbedtls_des_setkey_dec( &ctx, des3_test_keys );
ret = mbedtls_des_setkey_dec( &ctx, des3_test_keys );
break;
case 1:
mbedtls_des_setkey_enc( &ctx, des3_test_keys );
ret = mbedtls_des_setkey_enc( &ctx, des3_test_keys );
break;
case 2:
mbedtls_des3_set2key_dec( &ctx3, des3_test_keys );
ret = mbedtls_des3_set2key_dec( &ctx3, des3_test_keys );
break;
case 3:
mbedtls_des3_set2key_enc( &ctx3, des3_test_keys );
ret = mbedtls_des3_set2key_enc( &ctx3, des3_test_keys );
break;
case 4:
mbedtls_des3_set3key_dec( &ctx3, des3_test_keys );
ret = mbedtls_des3_set3key_dec( &ctx3, des3_test_keys );
break;
case 5:
mbedtls_des3_set3key_enc( &ctx3, des3_test_keys );
ret = mbedtls_des3_set3key_enc( &ctx3, des3_test_keys );
break;
default:
return( 1 );
}
if( ret != 0 )
goto exit;
if( v == MBEDTLS_DES_DECRYPT )
{
for( j = 0; j < 100; j++ )
{
if( u == 0 )
mbedtls_des_crypt_cbc( &ctx, v, 8, iv, buf, buf );
ret = mbedtls_des_crypt_cbc( &ctx, v, 8, iv, buf, buf );
else
mbedtls_des3_crypt_cbc( &ctx3, v, 8, iv, buf, buf );
ret = mbedtls_des3_crypt_cbc( &ctx3, v, 8, iv, buf, buf );
if( ret != 0 )
goto exit;
}
}
else
@ -1014,9 +1037,11 @@ int mbedtls_des_self_test( int verbose )
unsigned char tmp[8];
if( u == 0 )
mbedtls_des_crypt_cbc( &ctx, v, 8, iv, buf, buf );
ret = mbedtls_des_crypt_cbc( &ctx, v, 8, iv, buf, buf );
else
mbedtls_des3_crypt_cbc( &ctx3, v, 8, iv, buf, buf );
ret = mbedtls_des3_crypt_cbc( &ctx3, v, 8, iv, buf, buf );
if( ret != 0 )
goto exit;
memcpy( tmp, prv, 8 );
memcpy( prv, buf, 8 );
@ -1050,6 +1075,8 @@ exit:
mbedtls_des_free( &ctx );
mbedtls_des3_free( &ctx3 );
if( ret != 0 )
ret = 1;
return( ret );
}