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authormarkm <markm@FreeBSD.org>2002-07-15 13:58:35 +0000
committermarkm <markm@FreeBSD.org>2002-07-15 13:58:35 +0000
commit2370535caa1ffd00e4480c7894e5e9381e52520d (patch)
treefb7e9c3d811aeb44859d7b6f68ad78e9fda5e601
parenta22b6ae7fb60a1cfcb9cbdfc8e6146d714f11589 (diff)
downloadFreeBSD-src-2370535caa1ffd00e4480c7894e5e9381e52520d.zip
FreeBSD-src-2370535caa1ffd00e4480c7894e5e9381e52520d.tar.gz
Upgrade the random device to use a "real" hash instead of building
one out of a block cipher. This has 2 advantages: 1) The code is _much_ simpler 2) We aren't committing our security to one algorithm (much as we may think we trust AES). While I'm here, make an explicit reseed do a slow reseed instead of a fast; this is in line with what the original paper suggested.
Diffstat
-rw-r--r--sys/conf/files1
-rw-r--r--sys/dev/random/hash.c50
-rw-r--r--sys/dev/random/hash.h8
-rw-r--r--sys/dev/random/yarrow.c7
-rw-r--r--sys/modules/random/Makefile3
5 files changed, 14 insertions, 55 deletions
diff --git a/sys/conf/files b/sys/conf/files
index 5d25d3e..e27d638 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -507,6 +507,7 @@ dev/random/yarrow.c optional random
dev/random/hash.c optional random
crypto/rijndael/rijndael-alg-fst.c optional random
crypto/rijndael/rijndael-api-fst.c optional random
+crypto/sha2/sha2.c optional random
dev/ray/if_ray.c optional ray card
dev/ray/if_ray.c optional ray pccard
dev/rp/rp.c optional rp
diff --git a/sys/dev/random/hash.c b/sys/dev/random/hash.c
index a9246c3..98bd253 100644
--- a/sys/dev/random/hash.c
+++ b/sys/dev/random/hash.c
@@ -30,47 +30,22 @@
#include <sys/systm.h>
#include <crypto/rijndael/rijndael.h>
+#include <crypto/sha2/sha2.h>
#include <dev/random/hash.h>
-/* initialise the hash by zeroing it */
+/* initialise the hash */
void
yarrow_hash_init(struct yarrowhash *context)
{
- rijndael_cipherInit(&context->cipher, MODE_CBC, NULL);
- bzero(context->hash, KEYSIZE);
- context->partial = 0;
+ SHA256_Init(&context->sha);
}
-/* Do a Davies-Meyer hash using a block cipher.
- * H_0 = I
- * H_i = E_M_i(H_i-1) ^ H_i-1
- */
+/* iterate the hash */
void
yarrow_hash_iterate(struct yarrowhash *context, void *data, size_t size)
{
- u_char temp[KEYSIZE];
- u_int i, j;
- union {
- void *pv;
- char *pc;
- } trans;
-
- trans.pv = data;
- for (i = 0; i < size; i++) {
- context->accum[context->partial++] = trans.pc[i];
- if (context->partial == (KEYSIZE - 1)) {
- rijndael_makeKey(&context->hashkey, DIR_ENCRYPT,
- KEYSIZE*8, context->accum);
- rijndael_blockEncrypt(&context->cipher,
- &context->hashkey, context->hash,
- KEYSIZE*8, temp);
- for (j = 0; j < KEYSIZE; j++)
- context->hash[j] ^= temp[j];
- bzero(context->accum, KEYSIZE);
- context->partial = 0;
- }
- }
+ SHA256_Update(&context->sha, data, size);
}
/* Conclude by returning the hash in the supplied /buf/ which must be
@@ -80,20 +55,7 @@ yarrow_hash_iterate(struct yarrowhash *context, void *data, size_t size)
void
yarrow_hash_finish(struct yarrowhash *context, void *buf)
{
- u_char temp[KEYSIZE];
- int i;
-
- if (context->partial) {
- rijndael_makeKey(&context->hashkey, DIR_ENCRYPT,
- KEYSIZE*8, context->accum);
- rijndael_blockEncrypt(&context->cipher,
- &context->hashkey, context->hash,
- KEYSIZE*8, temp);
- for (i = 0; i < KEYSIZE; i++)
- context->hash[i] ^= temp[i];
- }
- memcpy(buf, context->hash, KEYSIZE);
- bzero(context->hash, KEYSIZE);
+ SHA256_Final(buf, &context->sha);
}
/* Initialise the encryption routine by setting up the key schedule
diff --git a/sys/dev/random/hash.h b/sys/dev/random/hash.h
index 5a30821..b307bfc 100644
--- a/sys/dev/random/hash.h
+++ b/sys/dev/random/hash.h
@@ -26,14 +26,10 @@
* $FreeBSD$
*/
-#define KEYSIZE 32 /* in bytes - 32 bytes == 256 bits */
+#define KEYSIZE 32 /* (in bytes) 32 bytes == 256 bits */
struct yarrowhash { /* Big! Make static! */
- keyInstance hashkey; /* Data cycles through here */
- cipherInstance cipher; /* Rijndael internal */
- u_char hash[KEYSIZE]; /* Repeatedly encrypted */
- char accum[KEYSIZE]; /* Accumulate partial chunks */
- u_int partial; /* Keep track of < KEYSIZE chunks */
+ SHA256_CTX sha;
};
struct yarrowkey { /* Big! Make static! */
diff --git a/sys/dev/random/yarrow.c b/sys/dev/random/yarrow.c
index dd79c34..9407892 100644
--- a/sys/dev/random/yarrow.c
+++ b/sys/dev/random/yarrow.c
@@ -35,6 +35,7 @@
#include <sys/sysctl.h>
#include <crypto/rijndael/rijndael.h>
+#include <crypto/sha2/sha2.h>
#include <dev/random/hash.h>
#include <dev/random/randomdev.h>
@@ -249,9 +250,7 @@ reseed(u_int fastslow)
random_unblock();
}
-/* Internal function to do return processed entropy from the
- * Yarrow PRNG
- */
+/* Internal function to return processed entropy from the PRNG */
int
read_random_real(void *buf, int count)
{
@@ -343,5 +342,5 @@ generator_gate(void)
void
random_reseed(void)
{
- reseed(FAST);
+ reseed(SLOW);
}
diff --git a/sys/modules/random/Makefile b/sys/modules/random/Makefile
index d88a19b..1e72868 100644
--- a/sys/modules/random/Makefile
+++ b/sys/modules/random/Makefile
@@ -2,10 +2,11 @@
.PATH: ${.CURDIR}/../../dev/random
.PATH: ${.CURDIR}/../../crypto/rijndael
+.PATH: ${.CURDIR}/../../crypto/sha2
KMOD= random
SRCS= randomdev.c yarrow.c hash.c
-SRCS+= rijndael-alg-fst.c rijndael-api-fst.c
+SRCS+= rijndael-alg-fst.c rijndael-api-fst.c sha2.c
SRCS+= bus_if.h device_if.h vnode_if.h
CFLAGS+= -I${.CURDIR}/../..
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