PERFORCE change 1199447 for review

[John-Mark Gurney]

http://p4web.freebsd.org/@@1199447?ac=10

Change 1199447 by jmg at jmg_carbon2 on 2014/08/27 22:48:16

	import OpenBSD's timingsafe_bcmp and use that for tag
	comparision...

Affected files ...

.. //depot/projects/opencrypto/sys/conf/files#6 edit
.. //depot/projects/opencrypto/sys/libkern/timingsafe_bcmp.c#1 add
.. //depot/projects/opencrypto/sys/opencrypto/cryptosoft.c#8 edit
.. //depot/projects/opencrypto/sys/sys/libkern.h#2 edit

Differences ...

==== //depot/projects/opencrypto/sys/conf/files#6 (text+ko) ====

@@ -3177,6 +3177,7 @@
 libkern/strtoul.c		standard
 libkern/strtouq.c		standard
 libkern/strvalid.c		standard
+libkern/timingsafe_bcmp.c	standard
 net/bpf.c			standard
 net/bpf_buffer.c		optional bpf
 net/bpf_jitter.c		optional bpf_jitter

==== //depot/projects/opencrypto/sys/opencrypto/cryptosoft.c#8 (text+ko) ====

@@ -481,10 +481,7 @@
 		crypto_copydata(crp->crp_flags, buf, crda->crd_inject,
 		    axf->hashsize, uaalg);
 
-		r = 0;
-		for (i = 0; i < axf->hashsize; i++)
-			r |= aalg[i] ^ uaalg[i];
-
+		r = timingsafe_bcmp(aalg, uaalg, axf->hashsize);
 		if (r == 0) {
 			/* tag matches, decrypt data */
 			for (i = 0; i < crde->crd_len; i += blksz) {

==== //depot/projects/opencrypto/sys/sys/libkern.h#2 (text+ko) ====

@@ -80,6 +80,8 @@
 uint32_t arc4random(void);
 void	 arc4rand(void *ptr, u_int len, int reseed);
 int	 bcmp(const void *, const void *, size_t);
+int	 timingsafe_bcmp(const void *, const void *, size_t);
+
 void	*bsearch(const void *, const void *, size_t,
 	    size_t, int (*)(const void *, const void *));
 #ifndef	HAVE_INLINE_FFS