diff options
author | Andy Polyakov <appro@openssl.org> | 2016-06-09 21:56:09 +0200 |
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committer | Andy Polyakov <appro@openssl.org> | 2016-06-12 13:47:57 +0200 |
commit | 5bbdc26cadc01cab811040e861f1f98e0f3af348 (patch) | |
tree | b96cdd0c906b00f40c3f0f0f0d42574b12f07733 | |
parent | 4f0b6e6775e4bd08cb2fc89a2f32c84c441f290d (diff) |
crypto/mem_clr.c: switch to OPENSSL_cleanse implementation from master.
It's probably worth reminding that this is a fall-back implementation
for platforms that don't have assembly OPENSSL_cleanse.
Reviewed-by: Rich Salz <rsalz@openssl.org>
-rw-r--r-- | crypto/mem_clr.c | 24 |
1 files changed, 9 insertions, 15 deletions
diff --git a/crypto/mem_clr.c b/crypto/mem_clr.c index ab85344eef..579e9d1825 100644 --- a/crypto/mem_clr.c +++ b/crypto/mem_clr.c @@ -60,22 +60,16 @@ #include <string.h> #include <openssl/crypto.h> -unsigned char cleanse_ctr = 0; +/* + * Pointer to memset is volatile so that compiler must de-reference + * the pointer and can't assume that it points to any function in + * particular (such as memset, which it then might further "optimize") + */ +typedef void *(*memset_t)(void *,int,size_t); + +static volatile memset_t memset_func = memset; void OPENSSL_cleanse(void *ptr, size_t len) { - unsigned char *p = ptr; - size_t loop = len, ctr = cleanse_ctr; - - if (ptr == NULL) - return; - - while (loop--) { - *(p++) = (unsigned char)ctr; - ctr += (17 + ((size_t)p & 0xF)); - } - p = memchr(ptr, (unsigned char)ctr, len); - if (p) - ctr += (63 + (size_t)p); - cleanse_ctr = (unsigned char)ctr; + memset_func(ptr, 0, len); } |