From 0b44d5cc79f7ef5ed876106c1a847e26d1e89559 Mon Sep 17 00:00:00 2001 From: Hanno Becker Date: Fri, 12 Oct 2018 16:46:37 +0100 Subject: [PATCH] Zeroize sensitive data in aescrypt2 and crypt_and_hash examples This commit replaces multiple `memset()` calls in the example programs aes/aescrypt2.c and aes/crypt_and_hash.c by calls to the reliable zeroization function `mbedtls_zeroize()`. While not a security issue because the code is in the example programs, it's bad practice and should be fixed. --- programs/aes/aescrypt2.c | 13 +++++++------ programs/aes/crypt_and_hash.c | 13 +++++++------ 2 files changed, 14 insertions(+), 12 deletions(-) diff --git a/programs/aes/aescrypt2.c b/programs/aes/aescrypt2.c index 69c406000..5725eb0f3 100644 --- a/programs/aes/aescrypt2.c +++ b/programs/aes/aescrypt2.c @@ -43,6 +43,7 @@ #include "mbedtls/aes.h" #include "mbedtls/md.h" +#include "mbedtls/platform_util.h" #include #include @@ -450,13 +451,13 @@ exit: 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 < (unsigned int) argc; i++ ) - memset( argv[i], 0, strlen( argv[i] ) ); + mbedtls_platform_zeroize( argv[i], 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 ) ); + mbedtls_platform_zeroize( IV, sizeof( IV ) ); + mbedtls_platform_zeroize( key, sizeof( key ) ); + mbedtls_platform_zeroize( tmp, sizeof( tmp ) ); + mbedtls_platform_zeroize( buffer, sizeof( buffer ) ); + mbedtls_platform_zeroize( digest, sizeof( digest ) ); mbedtls_aes_free( &aes_ctx ); mbedtls_md_free( &sha_ctx ); diff --git a/programs/aes/crypt_and_hash.c b/programs/aes/crypt_and_hash.c index bc95eb9be..88b852b4b 100644 --- a/programs/aes/crypt_and_hash.c +++ b/programs/aes/crypt_and_hash.c @@ -46,6 +46,7 @@ defined(MBEDTLS_FS_IO) #include "mbedtls/cipher.h" #include "mbedtls/md.h" +#include "mbedtls/platform_util.h" #include #include @@ -547,13 +548,13 @@ exit: the case when the user has missed or reordered some, in which case the key might not be in argv[6]. */ for( i = 0; i < argc; i++ ) - memset( argv[i], 0, strlen( argv[i] ) ); + mbedtls_platform_zeroize( argv[i], strlen( argv[i] ) ); - memset( IV, 0, sizeof( IV ) ); - memset( key, 0, sizeof( key ) ); - memset( buffer, 0, sizeof( buffer ) ); - memset( output, 0, sizeof( output ) ); - memset( digest, 0, sizeof( digest ) ); + mbedtls_platform_zeroize( IV, sizeof( IV ) ); + mbedtls_platform_zeroize( key, sizeof( key ) ); + mbedtls_platform_zeroize( buffer, sizeof( buffer ) ); + mbedtls_platform_zeroize( output, sizeof( output ) ); + mbedtls_platform_zeroize( digest, sizeof( digest ) ); mbedtls_cipher_free( &cipher_ctx ); mbedtls_md_free( &md_ctx );