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diff -up libgcrypt-1.5.3/random/random-csprng.c.rng-predictable libgcrypt-1.5.3/random/random-csprng.c
--- libgcrypt-1.5.3/random/random-csprng.c.rng-predictable 2015-08-11 14:31:35.904275580 +0200
+++ libgcrypt-1.5.3/random/random-csprng.c 2016-08-17 23:35:15.691980751 +0200
@@ -561,41 +561,46 @@ _gcry_rngcsprng_randomize (void *buffer,
/*
- Mix the pool:
-
- |........blocks*20byte........|20byte|..44byte..|
- <..44byte..> <20byte>
- | |
- | +------+
- +---------------------------|----------+
- v v
- |........blocks*20byte........|20byte|..44byte..|
- <.....64bytes.....>
- |
- +----------------------------------+
- Hash
- v
- |.............................|20byte|..44byte..|
- <20byte><20byte><..44byte..>
- | |
- | +---------------------+
- +-----------------------------+ |
- v v
- |.............................|20byte|..44byte..|
- <.....64byte......>
- |
- +-------------------------+
- Hash
- v
- |.............................|20byte|..44byte..|
- <20byte><20byte><..44byte..>
-
- and so on until we did this for all blocks.
-
- To better protect against implementation errors in this code, we
- xor a digest of the entire pool into the pool before mixing.
-
- Note: this function must only be called with a locked pool.
+ * Mix the 600 byte pool. Note that the 64 byte scratch area directly
+ * follows the pool. The numbers in the diagram give the number of
+ * bytes.
+ * <................600...............> <.64.>
+ * pool |------------------------------------| |------|
+ * <20><.24.> <20>
+ * | | +-----+
+ * +-----|-------------------------------|-+
+ * +-------------------------------|-|-+
+ * v v v
+ * |------|
+ * <hash>
+ * +---------------------------------------+
+ * v
+ * <20>
+ * pool' |------------------------------------|
+ * <20><20><.24.>
+ * +---|-----|---------------------------+
+ * +-----|---------------------------|-+
+ * +---------------------------|-|-+
+ * v v v
+ * |------|
+ * <hash>
+ * |
+ * +-----------------------------------+
+ * v
+ * <20>
+ * pool'' |------------------------------------|
+ * <20><20><20><.24.>
+ * +---|-----|-----------------------+
+ * +-----|-----------------------|-+
+ * +-----------------------|-|-+
+ * v v v
+ *
+ * and so on until we did this for all 30 blocks.
+ *
+ * To better protect against implementation errors in this code, we
+ * xor a digest of the entire pool into the pool before mixing.
+ *
+ * Note: this function must only be called with a locked pool.
*/
static void
mix_pool(unsigned char *pool)
@@ -615,32 +620,30 @@ mix_pool(unsigned char *pool)
gcry_assert (pool_is_locked);
_gcry_rmd160_init( &md );
- /* Loop over the pool. */
+ /* pool_0 -> pool'. */
pend = pool + POOLSIZE;
- memcpy(hashbuf, pend - DIGESTLEN, DIGESTLEN );
- memcpy(hashbuf+DIGESTLEN, pool, BLOCKLEN-DIGESTLEN);
- _gcry_rmd160_mixblock( &md, hashbuf);
- memcpy(pool, hashbuf, 20 );
+ memcpy (hashbuf, pend - DIGESTLEN, DIGESTLEN);
+ memcpy (hashbuf+DIGESTLEN, pool, BLOCKLEN-DIGESTLEN);
+ _gcry_rmd160_mixblock (&md, hashbuf);
+ memcpy (pool, hashbuf, DIGESTLEN);
if (failsafe_digest_valid && pool == rndpool)
{
- for (i=0; i < 20; i++)
+ for (i=0; i < DIGESTLEN; i++)
pool[i] ^= failsafe_digest[i];
}
+ /* Loop for the remaining iterations. */
p = pool;
for (n=1; n < POOLBLOCKS; n++)
{
- memcpy (hashbuf, p, DIGESTLEN);
-
- p += DIGESTLEN;
- if (p+DIGESTLEN+BLOCKLEN < pend)
- memcpy (hashbuf+DIGESTLEN, p+DIGESTLEN, BLOCKLEN-DIGESTLEN);
+ if (p + BLOCKLEN < pend)
+ memcpy (hashbuf, p, BLOCKLEN);
else
{
- unsigned char *pp = p + DIGESTLEN;
+ unsigned char *pp = p;
- for (i=DIGESTLEN; i < BLOCKLEN; i++ )
+ for (i=0; i < BLOCKLEN; i++ )
{
if ( pp >= pend )
pp = pool;
@@ -648,8 +651,9 @@ mix_pool(unsigned char *pool)
}
}
- _gcry_rmd160_mixblock ( &md, hashbuf);
- memcpy(p, hashbuf, 20 );
+ _gcry_rmd160_mixblock (&md, hashbuf);
+ p += DIGESTLEN;
+ memcpy (p, hashbuf, DIGESTLEN);
}
/* Our hash implementation does only leave small parts (64 bytes)