Add user pointer and data size duplication to ssl context.
Signed-off-by: Shelly Liberman <shelly.liberman@arm.com>
diff --git a/configs/baremetal.h b/configs/baremetal.h
index 5294351..6ed4b84 100644
--- a/configs/baremetal.h
+++ b/configs/baremetal.h
@@ -146,6 +146,9 @@
#define MBEDTLS_DEPRECATED_REMOVED
+/* Fault Injection Countermesures */
+#define MBEDTLS_FI_COUNTERMEASURES
+
#if defined(MBEDTLS_USER_CONFIG_FILE)
#include MBEDTLS_USER_CONFIG_FILE
#endif
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 4ee5920..4ac141e 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -655,6 +655,16 @@
//#define MBEDTLS_AES_SCA_COUNTERMEASURES
/**
+ * \def MBEDTLS_FI_COUNTERMEASURES
+ *
+ * Add countermeasures against possible FI attack.
+ *
+ * Uncommenting this macro inrease sode size and slow performence,
+ * it peforms double calls and double result checks of some crypto functions
+ */
+//#define MBEDTLS_FI_COUNTERMEASURES
+
+/**
* \def MBEDTLS_CAMELLIA_SMALL_MEMORY
*
* Use less ROM for the Camellia implementation (saves about 768 bytes).
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index e14f58f..ee231a5 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1460,6 +1460,10 @@
* after an initial handshake. */
unsigned char own_cid[ MBEDTLS_SSL_CID_IN_LEN_MAX ];
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
+#if defined(MBEDTLS_FI_COUNTERMEASURES)
+ unsigned char *out_msg_dup; /*!< out msg ptr duplication */
+ size_t out_msglen_dup; /*!< out msg size duplication */
+#endif
};
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index bbe94cb..a450819 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2562,7 +2562,6 @@
/* Not using more secure mbedtls_platform_memcpy as cid is public */
memcpy( rec->cid, transform->out_cid, transform->out_cid_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "CID", rec->cid, rec->cid_len );
-
if( rec->cid_len != 0 )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
@@ -11221,8 +11220,6 @@
{
int ret = mbedtls_ssl_get_max_out_record_payload( ssl );
const size_t max_len = (size_t) ret;
- volatile const unsigned char *buf_dup = buf;
- volatile size_t len_dup = len;
if( ret < 0 )
{
@@ -11245,7 +11242,6 @@
#if defined(MBEDTLS_SSL_PROTO_TLS)
{
len = max_len;
- len_dup = len;
}
#endif
}
@@ -11271,22 +11267,40 @@
* copy the data into the internal buffers and setup the data structure
* to keep track of partial writes
*/
- ssl->out_msglen = len;
+ ssl->out_msglen = len;
ssl->out_msgtype = MBEDTLS_SSL_MSG_APPLICATION_DATA;
- mbedtls_platform_memcpy( ssl->out_msg, buf, len );
+ mbedtls_platform_memcpy(ssl->out_msg, buf, len);
- if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
- {
- MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
- return( ret );
+#if defined(MBEDTLS_FI_COUNTERMEASURES) && !defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
+ /* Secure against buffer substitution */
+ if (buf == ssl->out_msg_dup &&
+ ssl->out_msglen == ssl->out_msglen_dup &&
+ ssl->out_msg_dup[0] == ssl->out_msg[0])
+ {/*write record only if data was copied from correct user pointer */
+#endif
+ if ((ret = mbedtls_ssl_write_record(ssl, SSL_FORCE_FLUSH)) != 0)
+ {
+ MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_write_record", ret);
+ return(ret);
+ }
+
+#if defined(MBEDTLS_FI_COUNTERMEASURES) && !defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
}
+ else
+ {
+ return(MBEDTLS_ERR_PLATFORM_FAULT_DETECTED);
+ }
+#endif
}
- /* Secure against buffer substitution */
- if( buf_dup == buf && len_dup == len )
+ if (ret == 0)
{
- return( (int) len );
+ return((int)len);
}
- return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
+ else
+ {
+ return(MBEDTLS_ERR_PLATFORM_FAULT_DETECTED);
+ }
+
}
/*
@@ -11334,10 +11348,11 @@
*/
int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len )
{
- int ret;
+ int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
+#if defined(MBEDTLS_FI_COUNTERMEASURES) && !defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
volatile const unsigned char *buf_dup = buf;
volatile size_t len_dup = len;
-
+#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write" ) );
if( ssl == NULL || ssl->conf == NULL )
@@ -11363,17 +11378,19 @@
#if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
ret = ssl_write_split( ssl, buf, len );
#else
+#if defined(MBEDTLS_FI_COUNTERMEASURES)
+ /*Add const user pointers to context. We will be able to check its validity before copy to context*/
+ ssl->out_msg_dup = (unsigned char*)buf_dup;
+ ssl->out_msglen_dup = len_dup;
+#endif //MBEDTLS_FI_COUNTERMEASURES
ret = ssl_write_real( ssl, buf, len );
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write" ) );
- /* Secure against buffer substitution */
- if( buf_dup == buf && len_dup == len )
- {
- return( ret );
- }
- return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
+
+ return( ret );
+
}
/*
diff --git a/library/version_features.c b/library/version_features.c
index d60758c..38a7cee 100644
--- a/library/version_features.c
+++ b/library/version_features.c
@@ -273,6 +273,9 @@
#if defined(MBEDTLS_AES_SCA_COUNTERMEASURES)
"MBEDTLS_AES_SCA_COUNTERMEASURES",
#endif /* MBEDTLS_AES_SCA_COUNTERMEASURES */
+#if defined(MBEDTLS_FI_COUNTERMEASURES)
+ "MBEDTLS_FI_COUNTERMEASURES",
+#endif /* MBEDTLS_FI_COUNTERMEASURES */
#if defined(MBEDTLS_CAMELLIA_SMALL_MEMORY)
"MBEDTLS_CAMELLIA_SMALL_MEMORY",
#endif /* MBEDTLS_CAMELLIA_SMALL_MEMORY */
diff --git a/programs/ssl/query_config.c b/programs/ssl/query_config.c
index 8093c0d..8db6d22 100644
--- a/programs/ssl/query_config.c
+++ b/programs/ssl/query_config.c
@@ -770,6 +770,14 @@
}
#endif /* MBEDTLS_AES_SCA_COUNTERMEASURES */
+#if defined(MBEDTLS_FI_COUNTERMEASURES)
+ if( strcmp( "MBEDTLS_FI_COUNTERMEASURES", config ) == 0 )
+ {
+ MACRO_EXPANSION_TO_STR( MBEDTLS_FI_COUNTERMEASURES );
+ return( 0 );
+ }
+#endif /* MBEDTLS_FI_COUNTERMEASURES */
+
#if defined(MBEDTLS_CAMELLIA_SMALL_MEMORY)
if( strcmp( "MBEDTLS_CAMELLIA_SMALL_MEMORY", config ) == 0 )
{