From d2cd28b99efa65dbd39cb8db0f2ad992be1aab00 Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Sat, 1 Sep 2018 12:19:30 +0200 Subject: [PATCH] err/err.c: add err_clear_last_constant_time. Expected usage pattern is to unconditionally set error and then wipe it if there was no actual error. Reviewed-by: Richard Levitte Reviewed-by: Matt Caswell (cherry picked from commit f658a3b64d8750642f4975090740865f770c2a1b) --- crypto/err/err.c | 21 +++++++++++++++++++++ include/internal/constant_time_locl.h | 6 ++++++ 2 files changed, 27 insertions(+) diff --git a/crypto/err/err.c b/crypto/err/err.c index 34061bc662..66a60e907c 100644 --- a/crypto/err/err.c +++ b/crypto/err/err.c @@ -20,6 +20,7 @@ #include #include "internal/thread_once.h" #include "internal/ctype.h" +#include "internal/constant_time_locl.h" static int err_load_strings(const ERR_STRING_DATA *str); @@ -878,3 +879,23 @@ int ERR_clear_last_mark(void) es->err_flags[top] &= ~ERR_FLAG_MARK; return 1; } + +void err_clear_last_constant_time(int clear) +{ + ERR_STATE *es; + int top; + + es = ERR_get_state(); + if (es == NULL) + return; + + top = es->top; + + es->err_flags[top] &= ~(0 - clear); + es->err_buffer[top] &= ~(0UL - clear); + es->err_file[top] = (const char *)((uintptr_t)es->err_file[top] & + ~((uintptr_t)0 - clear)); + es->err_line[top] |= 0 - clear; + + es->top = (top + ERR_NUM_ERRORS - clear) % ERR_NUM_ERRORS; +} diff --git a/include/internal/constant_time_locl.h b/include/internal/constant_time_locl.h index 82ff74652e..cde30f4067 100644 --- a/include/internal/constant_time_locl.h +++ b/include/internal/constant_time_locl.h @@ -324,4 +324,10 @@ static ossl_inline void constant_time_lookup(void *out, } } +/* + * Expected usage pattern is to unconditionally set error and then + * wipe it if there was no actual error. |clear| is 1 or 0. + */ +void err_clear_last_constant_time(int clear); + #endif /* HEADER_CONSTANT_TIME_LOCL_H */ -- 2.25.1