lib/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-07-28 00:21:48 +03:00
Code Activity

Use starts/finish around Lucky 13 dummy compressions

Browse Source 
Fixes #3246

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This commit is contained in:
Manuel Pégourié-Gonnard
2020-06-12 11:14:35 +02:00
parent 1fc09be3ea
commit f4e3fc9133
2 changed files with 16 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
library/ssl_msg.c
View File

@ -1578,6 +1578,8 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
* linking an extra division function in some builds).
*/
size_t j, extra_run = 0;
/* This size is enough to server either as input to
* md_process() or as output to md_finish() */
unsigned char tmp[MBEDTLS_MD_MAX_BLOCK_SIZE];
/*
@ -1633,10 +1635,15 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
ssl_read_memory( data + rec->data_len, padlen );
mbedtls_md_hmac_finish( &transform->md_ctx_dec, mac_expect );
/* Call mbedtls_md_process at least once due to cache attacks
* that observe whether md_process() was called of not */
/* Dummy calls to compression function.
* Call mbedtls_md_process at least once due to cache attacks
* that observe whether md_process() was called of not.
* Respect the usual start-(process|update)-finish sequence for
* the sake of hardware accelerators that might require it. */
mbedtls_md_starts( &transform->md_ctx_dec );
for( j = 0; j < extra_run + 1; j++ )
mbedtls_md_process( &transform->md_ctx_dec, tmp );
mbedtls_md_finish( &transform->md_ctx_dec, tmp );
mbedtls_md_hmac_reset( &transform->md_ctx_dec );