yuzu-emu/mbedtls
1
0
Fork 0
mirror of https://github.com/yuzu-emu/mbedtls.git synced 2024-11-23 04:25:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

Reliably zeroize sensitive data in AES sample application

Browse Source 
The AES sample application programs/aes/aescrypt2 could miss zeroizing
the stack-based key buffer in case of an error during operation. This
commit fixes this and also clears another temporary buffer as well as
all command line arguments (one of which might be the key) before exit.
This commit is contained in:
Hanno Becker 2017-06-27 08:24:34 +01:00 committed by Simon Butcher
parent e0c35a6997
commit 66daa68c19
1 changed files with 15 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
programs/aes/aescrypt2.c
View File

@ -79,7 +79,9 @@ int main( int argc, char *argv[] )
FILE *fkey, *fin = NULL, *fout = NULL;
char *p;
unsigned char IV[16];
unsigned char tmp[16];
unsigned char key[512];
unsigned char digest[32];
unsigned char buffer[1024];
@ -123,10 +125,10 @@ int main( int argc, char *argv[] )
}
mode = atoi( argv[1] );
memset(IV, 0, sizeof(IV));
memset(key, 0, sizeof(key));
memset(digest, 0, sizeof(digest));
memset(buffer, 0, sizeof(buffer));
memset( IV, 0, sizeof( IV ) );
memset( key, 0, sizeof( key ) );
memset( digest, 0, sizeof( digest ) );
memset( buffer, 0, sizeof( buffer ) );
if( mode != MODE_ENCRYPT && mode != MODE_DECRYPT )
{
@ -185,8 +187,6 @@ int main( int argc, char *argv[] )
}
}
memset( argv[4], 0, strlen( argv[4] ) );
#if defined(_WIN32_WCE)
filesize = fseek( fin, 0L, SEEK_END );
#else
@ -272,7 +272,6 @@ int main( int argc, char *argv[] )
mbedtls_md_finish( &sha_ctx, digest );
}
memset( key, 0, sizeof( key ) );
mbedtls_aes_setkey_enc( &aes_ctx, digest, 256 );
mbedtls_md_hmac_starts( &sha_ctx, digest, 32 );
@ -319,7 +318,6 @@ int main( int argc, char *argv[] )
if( mode == MODE_DECRYPT )
{
unsigned char tmp[16];
/*
* The encrypted file must be structured as follows:
@ -374,7 +372,6 @@ int main( int argc, char *argv[] )
mbedtls_md_finish( &sha_ctx, digest );
}
memset( key, 0, sizeof( key ) );
mbedtls_aes_setkey_dec( &aes_ctx, digest, 256 );
mbedtls_md_hmac_starts( &sha_ctx, digest, 32 );
@ -441,6 +438,15 @@ exit:
if( fout )
fclose( fout );
/* Zeroize all command line arguments to also cover
the case when the user has missed or reordered some,
in which case the key might not be in argv[4]. */
for( i = 0; i < argc; i++ )
memset( argv[i], 0, strlen( argv[i] ) );
memset( IV, 0, sizeof( IV ) );
memset( key, 0, sizeof( key ) );
memset( tmp, 0, sizeof( tmp ) );
memset( buffer, 0, sizeof( buffer ) );
memset( digest, 0, sizeof( digest ) );