Re: [PROPOSAL/PATCH] Fortuna PRNG in /dev/random

Jean-Luc Cooke
2004-09-24T13:50:21Z

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On Fri, Sep 24, 2004 at 12:38:51AM -0400, Theodore Ts'o wrote:
> I'm also a bit concerned about how much time AES takes over the
> cut-down MD4, as this may affect networking benchmarks. (And we don't
> need super-strength crypto here.)

Oh,

openssl speed md4 aes shows:

type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
md4 10708.72k 38240.96k 111170.47k 215872.85k 296828.93k
aes-128 cbc 32121.81k 32678.31k 33119.49k 33221.29k 33210.59k
aes-192 cbc 27915.92k 27868.52k 28418.08k 28677.12k 28721.15k
aes-256 cbc 24599.57k 25142.38k 25381.80k 25474.88k 25392.46k

Since we're using small blocks.

Attached is the patch with the problems Ted pointed out.

JLC

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diff -uNr linux-2.6.8.1-orig/include/linux/sysctl.h linux-2.6.8.1-fortuna/include/linux/sysctl.h
--- linux-2.6.8.1-orig/include/linux/sysctl.h 2004-08-14 12:55:33.000000000 +0200
+++ linux-2.6.8.1-fortuna/include/linux/sysctl.h 2004-09-13 18:55:43.000000000 +0200
@@ -198,7 +198,8 @@
RANDOM_READ_THRESH=3,
RANDOM_WRITE_THRESH=4,
RANDOM_BOOT_ID=5,
- RANDOM_UUID=6
+ RANDOM_UUID=6,
+ RANDOM_DERIVE_SEED=7
};

/* /proc/sys/kernel/pty */
--- linux-2.6.8.1/drivers/char/random.c 2004-09-24 08:32:30.222610504 -0400
+++ linux-2.6.8.1-rand2/drivers/char/random.c 2004-09-24 09:31:30.251444320 -0400
@@ -2,9 +2,11 @@
* random.c -- A strong random number generator
*
* Version 1.89, last modified 19-Sep-99
+ * Version 2.01, last modified 24-Sep-2004
*
* Copyright Theodore Ts'o, 1994, 1995, 1996, 1997, 1998, 1999. All
* rights reserved.
+ * Copyright Jean-Luc Cooke, 2004. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -40,61 +42,157 @@
*/

/*
- * (now, with legal B.S. out of the way.....)
- *
- * This routine gathers environmental noise from device drivers, etc.,
- * and returns good random numbers, suitable for cryptographic use.
- * Besides the obvious cryptographic uses, these numbers are also good
- * for seeding TCP sequence numbers, and other places where it is
- * desirable to have numbers which are not only random, but hard to
- * predict by an attacker.
- *
- * Theory of operation
- * ===================
- *
- * Computers are very predictable devices. Hence it is extremely hard
- * to produce truly random numbers on a computer --- as opposed to
- * pseudo-random numbers, which can easily generated by using a
- * algorithm. Unfortunately, it is very easy for attackers to guess
- * the sequence of pseudo-random number generators, and for some
- * applications this is not acceptable. So instead, we must try to
- * gather "environmental noise" from the computer's environment, which
- * must be hard for outside attackers to observe, and use that to
- * generate random numbers. In a Unix environment, this is best done
- * from inside the kernel.
- *
- * Sources of randomness from the environment include inter-keyboard
- * timings, inter-interrupt timings from some interrupts, and other
- * events which are both (a) non-deterministic and (b) hard for an
- * outside observer to measure. Randomness from these sources are
- * added to an "entropy pool", which is mixed using a CRC-like function.
- * This is not cryptographically strong, but it is adequate assuming
- * the randomness is not chosen maliciously, and it is fast enough that
- * the overhead of doing it on every interrupt is very reasonable.
- * As random bytes are mixed into the entropy pool, the routines keep
- * an *estimate* of how many bits of randomness have been stored into
- * the random number generator's internal state.
- *
- * When random bytes are desired, they are obtained by taking the SHA
- * hash of the contents of the "entropy pool". The SHA hash avoids
- * exposing the internal state of the entropy pool. It is believed to
- * be computationally infeasible to derive any useful information
- * about the input of SHA from its output. Even if it is possible to
- * analyze SHA in some clever way, as long as the amount of data
- * returned from the generator is less than the inherent entropy in
- * the pool, the output data is totally unpredictable. For this
- * reason, the routine decreases its internal estimate of how many
- * bits of "true randomness" are contained in the entropy pool as it
- * outputs random numbers.
- *
- * If this estimate goes to zero, the routine can still generate
- * random numbers; however, an attacker may (at least in theory) be
- * able to infer the future output of the generator from prior
- * outputs. This requires successful cryptanalysis of SHA, which is
- * not believed to be feasible, but there is a remote possibility.
- * Nonetheless, these numbers should be useful for the vast majority
- * of purposes.
- *
+ * The entire PRNG used in this file was replaced using a variant of the Fortuna
+ * PRNG described in Practical Cryptography by Ferguson and Schnier.
+ *
+ * The changes to their design include:
+ * - feeding the output of each pool back into their input to carry entropy
+ * forward (avoids pool overflow attacks like
+ * "dd if=/dev/zero of=/dev/random"
+ *
+ * Also, the entropy estimator was removed since it is not needed for
+ * cryptographically secure random data and such constructions are
+ * historically prone to attack
+ * [read Practical Cryptography].
+ *
+ * The Fortuna PRNG as described in Practical Cryptography is implemented here.
+ *
+ * Pseudo-code follows.
+ *
+create_entropy_pool(r)
+ - create an entropy pool in "r"
+
+ r.pool0_len = 0;
+ r.reseed_count = 0;
+ r.derive_count = 0;
+ r.digestsize = // digest size for our hash
+ r.blocksize = // block size for our cipher
+ r.keysize = // key size for our cipher
+ for (i=0; i&lt;32; i++) {
+ crypto_digest_init(r.pool[i]);
+ }
+ memset(r.key, 0, r.keysize);
+ crypto_cipher_setkey(r.cipher, r.key, r.keysize);
+
+add_entropy_words(r, in, nwords)
+ - mix 32bit word array "in" which is "nwords" long into pool "r"
+
+ crypto_digest_update(r.pool[i], in, nwords*sizeof(in[0]));
+ if (r.pool_index == 0)
+ r.pool0_len += nwords*sizeof(in[0]);
+ r.pool_index = r.pool_index + 1 mod (2number of pools - 1)
+
+random_reseed(r)
+ - reseed the key from the pooling system
+
+ r.reseed_count++;
+
+ crypto_digest_init(hash);
+ crypto_digest_update(hash, r.key, r.keysize);
+
+ for (i=0; i&lt;32; i++) {
+ if (2i is a factor of r.reseed_count) {
+ crypto_digest_final(r.pool[i], tmp);
+ crypto_digest_init(r.poo[i]);
+ crypto_digest_update(hash, tmp, r.digestsize);
+
+ // jlcooke: small change from Ferguson
+ crypto_digest_update(r.pool[i], tmp, r.digestsize);
+ }
+ }
+
+ crypto_digest_final(hash, tmp);
+ crypto_cipher_setkey(r.cipher, tmp, r.keysize);
+ r.ctrValue = r.ctrValue + 1 mod (2number of pools - 1)
+
+extract_entropy(r, buf, nbytes, flags)
+ - fill byte array "buf" with "nbytes" of random data from entropy pool "r"
+
+ random_reseed(r);
+ r.pool0_len = 0;
+
+ while (nbytes &gt; 0) {
+ crypto_cipher_encrypt(r.cipher, tmp, r.ctrValue, r.blocksize);
+ r.ctrValue++; // modulo 2r.blocksize/8
+
+ //
+ // Copy r.blocksize of tmp to the user
+ // Unless nbytes is less than r.blocksize, in which case only copy nbytes
+ //
+
+ nbytes -= r.blocksize;
+ }
+
+ // generate a new key
+ crypto_cipher_encrypt(r.cipher, r.key, r.ctrValue, r.blocksize);
+ crypto_cipher_setkey(r.cipher, r.key, r.keysize);
+
+derive_pool(r, buf)
+ - Fill "buf" with the output from a 1-way transformation of all 32-pools
+
+ memset(tmp, 0, r.digestsize);
+ r.pool0_len = 0;
+
+ for (i=0; i&lt;32; i++) {
+ crypto_digest_init(hash);
+
+ crypto_digest_update(hash, tmp, r.digestsize);
+
+ crypto_digest_final(r.pool[i], tmp);
+ crypto_digest_init(r.pool[i]);
+ crypto_digest_update(hash, tmp, r.digestsize);
+
+ crypto_digest_update(hash, r.derive_count, sizeof(r.derive_count));
+
+ crypto_digest_final(hash, tmp);
+
+ // Replace all 0x00 in "tmp" with "0x01" because the API to return a byte
+ // array does not exist. Only a "return string" API is provided. This
+ // reduces the effective entropy of the output by 0.39%.
+ //
+
+ memcpy(&amp;buf[i*r.digestsize], tmp, r.digestsize);
+ r.derive_count++;
+ }
+ *
+ * Draft Security Statement/Analysis (Jean-Luc Cooke <jlcooke@certainkey.com>)
+ *
+ * The Fortuna PRNG is resilliant to all known and preventable PRNG attacks.
+ * Proof of strength to these attacks can be done by reduction to the security
+ * of the underlying cryptographic primitives.
+ * * H = HASH(M)
+ * + M={0,1}^Mlen 0 <= Mlen < infinity
+ * + H={0,1}^Hlen 256 <= Hlen
+ * * C = ENCRYPT(K,M)
+ * + K={0,1}^Klen 256 <= Klen
+ * + M={0,1}^Mlen Mlen = 128
+ * + C={0,1}^Clen Clen = 128
+ *
+ * - Invertability of the output function
+ * The state of the output function Output[i] = ENCRYPT(KEY, CTR++) is
+ * {KEY,CTR} To recover the state {KEY,CTR} the attacker must be able to
+ * mount a known-plaintext or a known-ciphertext attack on the block cipher
+ * C=ENCRYPT(K,M) with N blocks.
+ * N = ReseedIntervalInSeconds * OutputRateInBytesPerSecond / BytesPerBlock
+ * AES256 in CTR is secure from known-plaintext/ciphertext key recovery
+ * attacks with N < 2^128
+ * However, After 2^64 blocks (2^71 bits) an attacker would have a 0.5 chance
+ * to guessing the next 128bit output. N <<< 2^64
+ *
+ * - Invertability of the pool mixing function
+ * The pool mixing function H' = HASH(H' || M) is said to be non-inveretable
+ * if H=HASH(MSG) is invertable.
+ * There have been no invertability discoveries in SHA-256.
+ *
+ * - Manipulating pool mixing
+ * An attack who has access to one or all of the entropy event sources may
+ * be able to input mallicious event data to alter any one of the pool states
+ * into a degenerate state. This requires that the underlying H=HASH(MSG)
+ * function is suseptible to a 1st pre-image attack. SHA-256 has no such
+ * known attacks.
+ */
+
+/*
* Exported interfaces ---- output
* ===============================
*
@@ -107,17 +205,13 @@
* and place it in the requested buffer.
*
* The two other interfaces are two character devices /dev/random and
- * /dev/urandom. /dev/random is suitable for use when very high
- * quality randomness is desired (for example, for key generation or
- * one-time pads), as it will only return a maximum of the number of
- * bits of randomness (as estimated by the random number generator)
- * contained in the entropy pool.
- *
- * The /dev/urandom device does not have this limit, and will return
- * as many bytes as are requested. As more and more random bytes are
- * requested without giving time for the entropy pool to recharge,
- * this will result in random numbers that are merely cryptographically
- * strong. For many applications, however, this is acceptable.
+ * /dev/urandom. They are synonymous with eachother for legacy reasons
+ *
+ * Both the devices will return as many bytes as are requested. As more
+ * and more random bytes are requested without giving time for the entropy
+ * pool to recharge, this will result in random numbers that are merely
+ * cryptographically strong. For many applications, however, this is
+ * acceptable.
*
* Exported interfaces ---- input
* ==============================
@@ -160,32 +254,28 @@
* following lines an appropriate script which is run during the boot
* sequence:
*
- * echo "Initializing random number generator..."
- * random_seed=/var/run/random-seed
- * # Carry a random seed from start-up to start-up
- * # Load and then save the whole entropy pool
- * if [ -f $random_seed ]; then
- * cat $random_seed >/dev/urandom
- * else
- * touch $random_seed
- * fi
- * chmod 600 $random_seed
- * poolfile=/proc/sys/kernel/random/poolsize
- * [ -r $poolfile ] && bytes=`cat $poolfile` || bytes=512
- * dd if=/dev/urandom of=$random_seed count=1 bs=$bytes
+ * echo "Initializing random number generator..."
+ * random_seed=/var/run/random-seed
+ * # Carry a random seed from start-up to start-up
+ * # Load and then save the whole entropy pool
+ * if [ -f $random_seed ]; then
+ * cat $random_seed >/dev/urandom
+ * else
+ * touch $random_seed
+ * fi
+ * chmod 600 $random_seed
+ * dd if=/proc/sys/kernel/random/derive_seed of=$random_seed
*
* and the following lines in an appropriate script which is run as
* the system is shutdown:
*
- * # Carry a random seed from shut-down to start-up
- * # Save the whole entropy pool
- * echo "Saving random seed..."
- * random_seed=/var/run/random-seed
- * touch $random_seed
- * chmod 600 $random_seed
- * poolfile=/proc/sys/kernel/random/poolsize
- * [ -r $poolfile ] && bytes=`cat $poolfile` || bytes=512
- * dd if=/dev/urandom of=$random_seed count=1 bs=$bytes
+ * # Carry a random seed from shut-down to start-up
+ * # Save the whole entropy pool
+ * echo "Saving random seed..."
+ * random_seed=/var/run/random-seed
+ * touch $random_seed
+ * chmod 600 $random_seed
+ * dd if=/proc/sys/kernel/random/derive_seed of=$random_seed
*
* For example, on most modern systems using the System V init
* scripts, such code fragments would be found in
@@ -215,22 +305,11 @@
* Acknowledgements:
* =================
*
- * Ideas for constructing this random number generator were derived
- * from Pretty Good Privacy's random number generator, and from private
- * discussions with Phil Karn. Colin Plumb provided a faster random
- * number generator, which speed up the mixing function of the entropy
- * pool, taken from PGPfone. Dale Worley has also contributed many
- * useful ideas and suggestions to improve this driver.
+ * The design for this RNG come from Fortuna as explined above.
+ * Cryptographic implementations are used from the CryptoAPI.
*
* Any flaws in the design are solely my responsibility, and should
- * not be attributed to the Phil, Colin, or any of authors of PGP.
- *
- * The code for SHA transform was taken from Peter Gutmann's
- * implementation, which has been placed in the public domain.
- * The code for MD5 transform was taken from Colin Plumb's
- * implementation, which has been placed in the public domain.
- * The MD5 cryptographic checksum was devised by Ronald Rivest, and is
- * documented in RFC 1321, "The MD5 Message Digest Algorithm".
+ * not be attributed to the Ted, Phil, Colin, or any of authors of PGP.
*
* Further background information on this topic may be obtained from
* RFC 1750, "Randomness Recommendations for Security", by Donald
@@ -254,137 +333,43 @@
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/percpu.h>
+#include <linux/crypto.h>
+#include <../crypto/internal.h>

+#include <asm/scatterlist.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>

-/*
- * Configuration information
- */
-#define DEFAULT_POOL_SIZE 512
-#define SECONDARY_POOL_SIZE 128
-#define BATCH_ENTROPY_SIZE 256
-#define USE_SHA
-
-/*
- * The minimum number of bits of entropy before we wake up a read on
- * /dev/random. Should be enough to do a significant reseed.
- */
-static int random_read_wakeup_thresh = 64;
-
-/*
- * If the entropy count falls under this number of bits, then we
- * should wake up processes which are selecting or polling on write
- * access to /dev/random.
- */
-static int random_write_wakeup_thresh = 128;
-
-/*
- * When the input pool goes over trickle_thresh, start dropping most
- * samples to avoid wasting CPU time and reduce lock contention.
- */
-
-static int trickle_thresh = DEFAULT_POOL_SIZE * 7;
-
-static DEFINE_PER_CPU(int, trickle_count) = 0;
+#if 0
+ #define DEBUG_PRINTK printk
+#else
+ #define DEBUG_PRINTK debug_printk
+static inline void debug_printk(const char *a, ...) {}
+#endif

/*
- * A pool of size .poolwords is stirred with a primitive polynomial
- * of degree .poolwords over GF(2). The taps for various sizes are
- * defined below. They are chosen to be evenly spaced (minimum RMS
- * distance from evenly spaced; the numbers in the comments are a
- * scaled squared error sum) except for the last tap, which is 1 to
- * get the twisting happening as fast as possible.
+ * Configuration information
*/
-static struct poolinfo {
- int poolwords;
- int tap1, tap2, tap3, tap4, tap5;
-} poolinfo_table[] = {
- /* x^2048 + x^1638 + x^1231 + x^819 + x^411 + x + 1 -- 115 */
- { 2048, 1638, 1231, 819, 411, 1 },
-
- /* x^1024 + x^817 + x^615 + x^412 + x^204 + x + 1 -- 290 */
- { 1024, 817, 615, 412, 204, 1 },
-#if 0 /* Alternate polynomial */
- /* x^1024 + x^819 + x^616 + x^410 + x^207 + x^2 + 1 -- 115 */
- { 1024, 819, 616, 410, 207, 2 },
-#endif
-
- /* x^512 + x^411 + x^308 + x^208 + x^104 + x + 1 -- 225 */
- { 512, 411, 308, 208, 104, 1 },
-#if 0 /* Alternates */
- /* x^512 + x^409 + x^307 + x^206 + x^102 + x^2 + 1 -- 95 */
- { 512, 409, 307, 206, 102, 2 },
- /* x^512 + x^409 + x^309 + x^205 + x^103 + x^2 + 1 -- 95 */
- { 512, 409, 309, 205, 103, 2 },
-#endif
-
- /* x^256 + x^205 + x^155 + x^101 + x^52 + x + 1 -- 125 */
- { 256, 205, 155, 101, 52, 1 },
-
- /* x^128 + x^103 + x^76 + x^51 +x^25 + x + 1 -- 105 */
- { 128, 103, 76, 51, 25, 1 },
-#if 0 /* Alternate polynomial */
- /* x^128 + x^103 + x^78 + x^51 + x^27 + x^2 + 1 -- 70 */
- { 128, 103, 78, 51, 27, 2 },
-#endif
-
- /* x^64 + x^52 + x^39 + x^26 + x^14 + x + 1 -- 15 */
- { 64, 52, 39, 26, 14, 1 },
-
- /* x^32 + x^26 + x^20 + x^14 + x^7 + x + 1 -- 15 */
- { 32, 26, 20, 14, 7, 1 },
-
- { 0, 0, 0, 0, 0, 0 },
-};
-
-#define POOLBITS poolwords*32
-#define POOLBYTES poolwords*4
+#define BATCH_ENTROPY_SIZE 512 /* how many events do we buffer? BATCH_ENTROPY_SIZE/2 == how many we need before batch-submitting them */
+#define RANDOM_RESEED_INTERVAL 600 /* reseed the PRNG output state every 5mins */
+#define RANDOM_DEFAULT_CIPHER_ALGO "aes"
+#define RANDOM_DEFAULT_DIGEST_ALGO "sha256"
+
+#define DEFAULT_POOL_NUMBER 5 /* 2^{5} = 32 pools */
+#define MAXIMUM_POOL_NUMBER DEFAULT_POOL_NUMBER
+#define MINIMUM_POOL_NUMBER 2 /* 2^{2} = 4 pools */
+#define USE_SHA256
+#define RANDOM_MAX_DIGEST_SIZE 64 /* SHA512/WHIRLPOOL have 64bytes == 512 bits */
+#define RANDOM_MAX_BLOCK_SIZE 16 /* AES256 has 16byte blocks == 128 bits */
+#define RANDOM_MAX_KEY_SIZE 32 /* AES256 has 32byte keys == 256 bits */
+#define USE_AES256

/*
- * For the purposes of better mixing, we use the CRC-32 polynomial as
- * well to make a twisted Generalized Feedback Shift Reigster
- *
- * (See M. Matsumoto & Y. Kurita, 1992. Twisted GFSR generators. ACM
- * Transactions on Modeling and Computer Simulation 2(3):179-194.
- * Also see M. Matsumoto & Y. Kurita, 1994. Twisted GFSR generators
- * II. ACM Transactions on Mdeling and Computer Simulation 4:254-266)
- *
- * Thanks to Colin Plumb for suggesting this.
- *
- * We have not analyzed the resultant polynomial to prove it primitive;
- * in fact it almost certainly isn't. Nonetheless, the irreducible factors
- * of a random large-degree polynomial over GF(2) are more than large enough
- * that periodicity is not a concern.
- *
- * The input hash is much less sensitive than the output hash. All
- * that we want of it is that it be a good non-cryptographic hash;
- * i.e. it not produce collisions when fed "random" data of the sort
- * we expect to see. As long as the pool state differs for different
- * inputs, we have preserved the input entropy and done a good job.
- * The fact that an intelligent attacker can construct inputs that
- * will produce controlled alterations to the pool's state is not
- * important because we don't consider such inputs to contribute any
- * randomness. The only property we need with respect to them is that
- * the attacker can't increase his/her knowledge of the pool's state.
- * Since all additions are reversible (knowing the final state and the
- * input, you can reconstruct the initial state), if an attacker has
- * any uncertainty about the initial state, he/she can only shuffle
- * that uncertainty about, but never cause any collisions (which would
- * decrease the uncertainty).
- *
- * The chosen system lets the state of the pool be (essentially) the input
- * modulo the generator polymnomial. Now, for random primitive polynomials,
- * this is a universal class of hash functions, meaning that the chance
- * of a collision is limited by the attacker's knowledge of the generator
- * polynomail, so if it is chosen at random, an attacker can never force
- * a collision. Here, we use a fixed polynomial, but we *can* assume that
- * ###--> it is unknown to the processes generating the input entropy. <-###
- * Because of this important property, this is a good, collision-resistant
- * hash; hash collisions will occur no more often than chance.
+ * Throttle mouse/keyboard/disk/interrupt entropy input to only add after this many jiffies/rdtsc counts
*/
+#define RANDOM_INPUT_THROTTLE 1000

/*
* Linux 2.2 compatibility
@@ -399,8 +384,10 @@
/*
* Static global variables
*/
+static int random_entropy_count; // jlc & cam have been together for 5 and 2/3 years as of the time this was written;
+static int random_read_wakeup_thresh = 0; // ignored now.
+static int random_write_wakeup_thresh = 0; // ignored now.
static struct entropy_store *random_state; /* The default global store */
-static struct entropy_store *sec_random_state; /* secondary store */
static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);

@@ -411,71 +398,6 @@
static void sysctl_init_random(struct entropy_store *random_state);
#endif

-/*****************************************************************
- *
- * Utility functions, with some ASM defined functions for speed
- * purposes
- *
- *****************************************************************/
-
-/*
- * Unfortunately, while the GCC optimizer for the i386 understands how
- * to optimize a static rotate left of x bits, it doesn't know how to
- * deal with a variable rotate of x bits. So we use a bit of asm magic.
- */
-#if (!defined (__i386__))
-static inline __u32 rotate_left(int i, __u32 word)
-{
- return (word << i) | (word >> (32 - i));
-
-}
-#else
-static inline __u32 rotate_left(int i, __u32 word)
-{
- __asm__("roll %%cl,%0"
- :"=r" (word)
- :"0" (word),"c" (i));
- return word;
-}
-#endif
-
-/*
- * More asm magic....
- *
- * For entropy estimation, we need to do an integral base 2
- * logarithm.
- *
- * Note the "12bits" suffix - this is used for numbers between
- * 0 and 4095 only. This allows a few shortcuts.
- */
-#if 0 /* Slow but clear version */
-static inline __u32 int_ln_12bits(__u32 word)
-{
- __u32 nbits = 0;
-
- while (word >>= 1)
- nbits++;
- return nbits;
-}
-#else /* Faster (more clever) version, courtesy Colin Plumb */
-static inline __u32 int_ln_12bits(__u32 word)
-{
- /* Smear msbit right to make an n-bit mask */
- word |= word >> 8;
- word |= word >> 4;
- word |= word >> 2;
- word |= word >> 1;
- /* Remove one bit to make this a logarithm */
- word >>= 1;
- /* Count the bits set in the word */
- word -= (word >> 1) & 0x555;
- word = (word & 0x333) + ((word >> 2) & 0x333);
- word += (word >> 4);
- word += (word >> 8);
- return word & 15;
-}
-#endif
-
#if 0
#define DEBUG_ENT(fmt, arg...) printk(KERN_DEBUG "random: " fmt, ## arg)
#else
@@ -490,15 +412,28 @@
**********************************************************************/

struct entropy_store {
- /* mostly-read data: */
- struct poolinfo poolinfo;
- __u32 *pool;
+ const char *digestAlgo;
+ unsigned int digestsize;
+ struct crypto_tfm *pools[1<<MAXIMUM_POOL_NUMBER];
+ /* optional, handy for statistics */
+ unsigned int pools_bytes[1<<MAXIMUM_POOL_NUMBER];
+
+ const char *cipherAlgo;
+ unsigned char key[RANDOM_MAX_DIGEST_SIZE]; /* the key */
+ unsigned int keysize;
+ unsigned char iv[16]; /* the CTR value */
+ unsigned int blocksize;
+ struct crypto_tfm *cipher;
+
+ unsigned int pool_number; /* 2^pool_number # of pools */
+ unsigned int pool_index; /* current pool to add into */
+ unsigned int pool0_len; /* size of the first pool */
+ unsigned int reseed_count; /* number of time we have reset */
+ struct crypto_tfm *reseedHash; /* digest used during random_reseed() */
+ struct crypto_tfm *networkCipher; /* cipher used for network randomness */
+ char networkCipher_ready; /* flag indicating if networkCipher has been seeded */

- /* read-write data: */
spinlock_t lock ____cacheline_aligned_in_smp;
- unsigned add_ptr;
- int entropy_count;
- int input_rotate;
};

/*
@@ -507,151 +442,107 @@
*
* Returns an negative error if there is a problem.
*/
-static int create_entropy_store(int size, struct entropy_store **ret_bucket)
+static int create_entropy_store(int pool_number_arg, struct entropy_store **ret_bucket)
{
struct entropy_store *r;
- struct poolinfo *p;
- int poolwords;
+ unsigned long pool_number;
+ int keysize, i, j;

- poolwords = (size + 3) / 4; /* Convert bytes->words */
- /* The pool size must be a multiple of 16 32-bit words */
- poolwords = ((poolwords + 15) / 16) * 16;
-
- for (p = poolinfo_table; p->poolwords; p++) {
- if (poolwords == p->poolwords)
- break;
- }
- if (p->poolwords == 0)
- return -EINVAL;
+ pool_number = pool_number_arg;
+ if (pool_number < MINIMUM_POOL_NUMBER)
+ pool_number = MINIMUM_POOL_NUMBER;

r = kmalloc(sizeof(struct entropy_store), GFP_KERNEL);
- if (!r)
+ if (!r) {
return -ENOMEM;
+ }

memset (r, 0, sizeof(struct entropy_store));
- r->poolinfo = *p;
+ r->pool_number = pool_number;
+ r->digestAlgo = RANDOM_DEFAULT_DIGEST_ALGO;

- r->pool = kmalloc(POOLBYTES, GFP_KERNEL);
- if (!r->pool) {
- kfree(r);
- return -ENOMEM;
+DEBUG_PRINTK("create_entropy_store() pools=%u index=%u\n", 1<<pool_number, r->pool_index);
+ for (i=0; i<(1<<pool_number); i++) {
+DEBUG_PRINTK("create_entropy_store() i=%i index=%u\n", i, r->pool_index);
+ r->pools[i] = crypto_alloc_tfm(r->digestAlgo, 0);
+ if (r->pools[i] == NULL) {
+ for (j=0; j<i; j++) {
+ if (r->pools[j] != NULL) {
+ kfree(r->pools[j]);
+ }
+ }
+ kfree(r);
+ return -ENOMEM;
+ }
+ crypto_digest_init( r->pools[i] );
}
- memset(r->pool, 0, POOLBYTES);
r->lock = SPIN_LOCK_UNLOCKED;
*ret_bucket = r;
- return 0;
-}

-/* Clear the entropy pool and associated counters. */
-static void clear_entropy_store(struct entropy_store *r)
-{
- r->add_ptr = 0;
- r->entropy_count = 0;
- r->input_rotate = 0;
- memset(r->pool, 0, r->poolinfo.POOLBYTES);
-}
-#ifdef CONFIG_SYSCTL
-static void free_entropy_store(struct entropy_store *r)
-{
- if (r->pool)
- kfree(r->pool);
- kfree(r);
-}
-#endif
-/*
- * This function adds a byte into the entropy "pool". It does not
- * update the entropy estimate. The caller should call
- * credit_entropy_store if this is appropriate.
- *
- * The pool is stirred with a primitive polynomial of the appropriate
- * degree, and then twisted. We twist by three bits at a time because
- * it's cheap to do so and helps slightly in the expected case where
- * the entropy is concentrated in the low-order bits.
- */
-static void add_entropy_words(struct entropy_store *r, const __u32 *in,
- int nwords)
-{
- static __u32 const twist_table[8] = {
- 0, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
- 0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
- unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
- int new_rotate, input_rotate;
- int wordmask = r->poolinfo.poolwords - 1;
- __u32 w, next_w;
- unsigned long flags;
+ r->cipherAlgo = RANDOM_DEFAULT_CIPHER_ALGO;
+ if ((r->cipher=crypto_alloc_tfm(r->cipherAlgo, 0)) == NULL) {
+ return -ENOMEM;
+ }

- /* Taps are constant, so we can load them without holding r->lock. */
- tap1 = r->poolinfo.tap1;
- tap2 = r->poolinfo.tap2;
- tap3 = r->poolinfo.tap3;
- tap4 = r->poolinfo.tap4;
- tap5 = r->poolinfo.tap5;
- next_w = *in++;
+ /* If the HASH's output is greater then the cipher's keysize, truncate
+ * to the cipher's keysize */
+ keysize = crypto_tfm_alg_max_keysize(r->cipher);
+ r->digestsize = crypto_tfm_alg_digestsize(r->pools[0]);
+ r->blocksize = crypto_tfm_alg_blocksize(r->cipher);

- spin_lock_irqsave(&r->lock, flags);
- prefetch_range(r->pool, wordmask);
- input_rotate = r->input_rotate;
- add_ptr = r->add_ptr;
-
- while (nwords--) {
- w = rotate_left(input_rotate, next_w);
- if (nwords > 0)
- next_w = *in++;
- i = add_ptr = (add_ptr - 1) & wordmask;
- /*
- * Normally, we add 7 bits of rotation to the pool.
- * At the beginning of the pool, add an extra 7 bits
- * rotation, so that successive passes spread the
- * input bits across the pool evenly.
- */
- new_rotate = input_rotate + 14;
- if (i)
- new_rotate = input_rotate + 7;
- input_rotate = new_rotate & 31;
-
- /* XOR in the various taps */
- w ^= r->pool[(i + tap1) & wordmask];
- w ^= r->pool[(i + tap2) & wordmask];
- w ^= r->pool[(i + tap3) & wordmask];
- w ^= r->pool[(i + tap4) & wordmask];
- w ^= r->pool[(i + tap5) & wordmask];
- w ^= r->pool[i];
- r->pool[i] = (w >> 3) ^ twist_table[w & 7];
+ r->keysize = (keysize < r->digestsize) ? keysize : r->digestsize;
+
+ if (crypto_cipher_setkey(r->cipher, r->key, r->keysize)) {
+ return -EINVAL;
}

- r->input_rotate = input_rotate;
- r->add_ptr = add_ptr;
+ /* digest used duing random-reseed() */
+ if ((r->reseedHash=crypto_alloc_tfm(r->digestAlgo, 0)) == NULL) {
+ return -ENOMEM;
+ }
+ /* cipher used for network randomness, init to key={zerovector}
+ * for now */
+ if ((r->networkCipher=crypto_alloc_tfm(r->cipherAlgo, 0)) == NULL) {
+ return -ENOMEM;
+ }

- spin_unlock_irqrestore(&r->lock, flags);
+ return 0;
}

/*
- * Credit (or debit) the entropy store with n bits of entropy
+ * This function adds a byte into the entropy "pool".
*/
-static void credit_entropy_store(struct entropy_store *r, int nbits)
+static void add_entropy_words(struct entropy_store *r, const __u32 *in,
+ int nwords)
{
unsigned long flags;
+ struct scatterlist sg[1];
+ static unsigned int totalBytes=0;
+
+ if (r == NULL) {
+ return;
+ }

spin_lock_irqsave(&r->lock, flags);

- if (r->entropy_count + nbits < 0) {
- DEBUG_ENT("negative entropy/overflow (%d+%d)\n",
- r->entropy_count, nbits);
- r->entropy_count = 0;
- } else if (r->entropy_count + nbits > r->poolinfo.POOLBITS) {
- r->entropy_count = r->poolinfo.POOLBITS;
- } else {
- r->entropy_count += nbits;
- if (nbits)
- DEBUG_ENT("%04d %04d : added %d bits to %s\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- nbits,
- r == sec_random_state ? "secondary" :
- r == random_state ? "primary" : "unknown");
+ totalBytes += nwords * sizeof(__u32);
+ r->pools_bytes[r->pool_index] += nwords * sizeof(__u32);
+
+ sg[0].page = virt_to_page(in);
+ sg[0].offset = offset_in_page(in);
+ sg[0].length = nwords*sizeof(__u32);
+ crypto_digest_update(r->pools[r->pool_index], sg, 1);
+
+ if (r->pool_index == 0) {
+ r->pool0_len += nwords*sizeof(__u32);
}

+ /* idx = (idx + 1) mod ( (2^N)-1 ) */
+ r->pool_index = (r->pool_index + 1) & ((1<<r->pool_number)-1);
+
spin_unlock_irqrestore(&r->lock, flags);
+DEBUG_PRINTK("0 add_entropy_words() nwords=%u pool[i].bytes=%u total=%u\n",
+ nwords, r->pools_bytes[r->pool_index], totalBytes);
}

/**********************************************************************
@@ -668,10 +559,10 @@
};

static struct sample *batch_entropy_pool, *batch_entropy_copy;
-static int batch_head, batch_tail;
+static int batch_head, batch_tail;
static spinlock_t batch_lock = SPIN_LOCK_UNLOCKED;

-static int batch_max;
+static int batch_max;
static void batch_entropy_process(void *private_);
static DECLARE_WORK(batch_work, batch_entropy_process, NULL);

@@ -703,19 +594,20 @@
int new;
unsigned long flags;

- if (!batch_max)
+ if (!batch_max) {
return;
+ }

spin_lock_irqsave(&batch_lock, flags);

batch_entropy_pool[batch_head].data[0] = a;
batch_entropy_pool[batch_head].data[1] = b;
- batch_entropy_pool[batch_head].credit = num;
+ batch_entropy_pool[batch_head].credit = 0;

if (((batch_head - batch_tail) & (batch_max-1)) >= (batch_max / 2)) {
/*
- * Schedule it for the next timer tick:
- */
+ * Schedule it for the next timer tick:
+ */
schedule_delayed_work(&batch_work, 1);
}

@@ -733,13 +625,11 @@

/*
* Flush out the accumulated entropy operations, adding entropy to the passed
- * store (normally random_state). If that store has enough entropy, alternate
- * between randomizing the data of the primary and secondary stores.
+ * store (normally random_state).
*/
static void batch_entropy_process(void *private_)
{
- struct entropy_store *r = (struct entropy_store *) private_, *p;
- int max_entropy = r->poolinfo.POOLBITS;
+ struct entropy_store *r = (struct entropy_store *) private_;
unsigned head, tail;

/* Mixing into the pool is expensive, so copy over the batch
@@ -750,7 +640,7 @@
spin_lock_irq(&batch_lock);

memcpy(batch_entropy_copy, batch_entropy_pool,
- batch_max*sizeof(struct sample));
+ batch_max*sizeof(struct sample));

head = batch_head;
tail = batch_tail;
@@ -758,61 +648,30 @@

spin_unlock_irq(&batch_lock);

- p = r;
while (head != tail) {
- if (r->entropy_count >= max_entropy) {
- r = (r == sec_random_state) ? random_state :
- sec_random_state;
- max_entropy = r->poolinfo.POOLBITS;
- }
add_entropy_words(r, batch_entropy_copy[tail].data, 2);
- credit_entropy_store(r, batch_entropy_copy[tail].credit);
tail = (tail+1) & (batch_max-1);
}
- if (p->entropy_count >= random_read_wakeup_thresh)
- wake_up_interruptible(&random_read_wait);
}

+
/*********************************************************************
*
* Entropy input management
*
*********************************************************************/

-/* There is one of these per entropy source */
-struct timer_rand_state {
- __u32 last_time;
- __s32 last_delta,last_delta2;
- int dont_count_entropy:1;
-};
-
-static struct timer_rand_state keyboard_timer_state;
-static struct timer_rand_state mouse_timer_state;
-static struct timer_rand_state extract_timer_state;
-static struct timer_rand_state *irq_timer_state[NR_IRQS];
-
/*
* This function adds entropy to the entropy "pool" by using timing
- * delays. It uses the timer_rand_state structure to make an estimate
- * of how many bits of entropy this call has added to the pool.
+ * delays.
*
* The number "num" is also added to the pool - it should somehow describe
- * the type of event which just happened. This is currently 0-255 for
- * keyboard scan codes, and 256 upwards for interrupts.
- * On the i386, this is assumed to be at most 16 bits, and the high bits
- * are used for a high-resolution timer.
- *
+ * the type of event which just happened.
*/
-static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
+static void add_timer_randomness(unsigned num)
{
- __u32 time;
- __s32 delta, delta2, delta3;
- int entropy = 0;
-
- /* if over the trickle threshold, use only 1 in 4096 samples */
- if ( random_state->entropy_count > trickle_thresh &&
- (__get_cpu_var(trickle_count)++ & 0xfff))
- return;
+ static __u32 lasttime=0;
+ __u32 time;

#if defined (__i386__) || defined (__x86_64__)
if (cpu_has_tsc) {
@@ -822,480 +681,57 @@
} else {
time = jiffies;
}
-#elif defined (__sparc_v9__)
- unsigned long tick = tick_ops->get_tick();
-
- time = (unsigned int) tick;
- num ^= (tick >> 32UL);
#else
time = jiffies;
#endif

- /*
- * Calculate number of bits of randomness we probably added.
- * We take into account the first, second and third-order deltas
- * in order to make our estimate.
- */
- if (!state->dont_count_entropy) {
- delta = time - state->last_time;
- state->last_time = time;
-
- delta2 = delta - state->last_delta;
- state->last_delta = delta;
-
- delta3 = delta2 - state->last_delta2;
- state->last_delta2 = delta2;
-
- if (delta < 0)
- delta = -delta;
- if (delta2 < 0)
- delta2 = -delta2;
- if (delta3 < 0)
- delta3 = -delta3;
- if (delta > delta2)
- delta = delta2;
- if (delta > delta3)
- delta = delta3;
-
- /*
- * delta is now minimum absolute delta.
- * Round down by 1 bit on general principles,
- * and limit entropy entimate to 12 bits.
- */
- delta >>= 1;
- delta &= (1 << 12) - 1;
-
- entropy = int_ln_12bits(delta);
+ /* Throttle our input to add_entropy_words() */
+ if ((time-lasttime) < RANDOM_INPUT_THROTTLE) {
+ return;
}
- batch_entropy_store(num, time, entropy);
+ lasttime = time;
+
+ batch_entropy_store(num, time, 0);
}

void add_keyboard_randomness(unsigned char scancode)
{
- static unsigned char last_scancode;
- /* ignore autorepeat (multiple key down w/o key up) */
- if (scancode != last_scancode) {
- last_scancode = scancode;
- add_timer_randomness(&keyboard_timer_state, scancode);
- }
+ /* jlcooke: we don't care about auto-repeats,
+ * they can't hurt us anymore */
+ add_timer_randomness(scancode);
}

EXPORT_SYMBOL(add_keyboard_randomness);

void add_mouse_randomness(__u32 mouse_data)
{
- add_timer_randomness(&mouse_timer_state, mouse_data);
+ add_timer_randomness(mouse_data);
}

EXPORT_SYMBOL(add_mouse_randomness);

void add_interrupt_randomness(int irq)
{
- if (irq >= NR_IRQS || irq_timer_state[irq] == 0)
+ if (irq >= NR_IRQS)
return;

- add_timer_randomness(irq_timer_state[irq], 0x100+irq);
+ /* jlcooke: no need to add 0x100 ... not random! :P */
+ add_timer_randomness(irq);
}

EXPORT_SYMBOL(add_interrupt_randomness);

void add_disk_randomness(struct gendisk *disk)
{
- if (!disk || !disk->random)
+ if (!disk)
return;
- /* first major is 1, so we get >= 0x200 here */
- add_timer_randomness(disk->random, 0x100+MKDEV(disk->major, disk->first_minor));
+
+ /* jlcooke: no need to add 0x100 ... not random! :P */
+ add_timer_randomness(MKDEV(disk->major, disk->first_minor));
}

EXPORT_SYMBOL(add_disk_randomness);

-/******************************************************************
- *
- * Hash function definition
- *
- *******************************************************************/
-
-/*
- * This chunk of code defines a function
- * void HASH_TRANSFORM(__u32 digest[HASH_BUFFER_SIZE + HASH_EXTRA_SIZE],
- * __u32 const data[16])
- *
- * The function hashes the input data to produce a digest in the first
- * HASH_BUFFER_SIZE words of the digest[] array, and uses HASH_EXTRA_SIZE
- * more words for internal purposes. (This buffer is exported so the
- * caller can wipe it once rather than this code doing it each call,
- * and tacking it onto the end of the digest[] array is the quick and
- * dirty way of doing it.)
- *
- * It so happens that MD5 and SHA share most of the initial vector
- * used to initialize the digest[] array before the first call:
- * 1) 0x67452301
- * 2) 0xefcdab89
- * 3) 0x98badcfe
- * 4) 0x10325476
- * 5) 0xc3d2e1f0 (SHA only)
- *
- * For /dev/random purposes, the length of the data being hashed is
- * fixed in length, so appending a bit count in the usual way is not
- * cryptographically necessary.
- */
-
-#ifdef USE_SHA
-
-#define HASH_BUFFER_SIZE 5
-#define HASH_EXTRA_SIZE 80
-#define HASH_TRANSFORM SHATransform
-
-/* Various size/speed tradeoffs are available. Choose 0..3. */
-#define SHA_CODE_SIZE 0
-
-/*
- * SHA transform algorithm, taken from code written by Peter Gutmann,
- * and placed in the public domain.
- */
-
-/* The SHA f()-functions. */
-
-#define f1(x,y,z) ( z ^ (x & (y^z)) ) /* Rounds 0-19: x ? y : z */
-#define f2(x,y,z) (x ^ y ^ z) /* Rounds 20-39: XOR */
-#define f3(x,y,z) ( (x & y) + (z & (x ^ y)) ) /* Rounds 40-59: majority */
-#define f4(x,y,z) (x ^ y ^ z) /* Rounds 60-79: XOR */
-
-/* The SHA Mysterious Constants */
-
-#define K1 0x5A827999L /* Rounds 0-19: sqrt(2) * 2^30 */
-#define K2 0x6ED9EBA1L /* Rounds 20-39: sqrt(3) * 2^30 */
-#define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */
-#define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */
-
-#define ROTL(n,X) ( ( ( X ) << n ) | ( ( X ) >> ( 32 - n ) ) )
-
-#define subRound(a, b, c, d, e, f, k, data) \
- ( e += ROTL( 5, a ) + f( b, c, d ) + k + data, b = ROTL( 30, b ) )
-
-
-static void SHATransform(__u32 digest[85], __u32 const data[16])
-{
- __u32 A, B, C, D, E; /* Local vars */
- __u32 TEMP;
- int i;
-#define W (digest + HASH_BUFFER_SIZE) /* Expanded data array */
-
- /*
- * Do the preliminary expansion of 16 to 80 words. Doing it
- * out-of-line line this is faster than doing it in-line on
- * register-starved machines like the x86, and not really any
- * slower on real processors.
- */
- memcpy(W, data, 16*sizeof(__u32));
- for (i = 0; i < 64; i++) {
- TEMP = W[i] ^ W[i+2] ^ W[i+8] ^ W[i+13];
- W[i+16] = ROTL(1, TEMP);
- }
-
- /* Set up first buffer and local data buffer */
- A = digest[ 0 ];
- B = digest[ 1 ];
- C = digest[ 2 ];
- D = digest[ 3 ];
- E = digest[ 4 ];
-
- /* Heavy mangling, in 4 sub-rounds of 20 iterations each. */
-#if SHA_CODE_SIZE == 0
- /*
- * Approximately 50% of the speed of the largest version, but
- * takes up 1/16 the space. Saves about 6k on an i386 kernel.
- */
- for (i = 0; i < 80; i++) {
- if (i < 40) {
- if (i < 20)
- TEMP = f1(B, C, D) + K1;
- else
- TEMP = f2(B, C, D) + K2;
- } else {
- if (i < 60)
- TEMP = f3(B, C, D) + K3;
- else
- TEMP = f4(B, C, D) + K4;
- }
- TEMP += ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
-#elif SHA_CODE_SIZE == 1
- for (i = 0; i < 20; i++) {
- TEMP = f1(B, C, D) + K1 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
- for (; i < 40; i++) {
- TEMP = f2(B, C, D) + K2 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
- for (; i < 60; i++) {
- TEMP = f3(B, C, D) + K3 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
- for (; i < 80; i++) {
- TEMP = f4(B, C, D) + K4 + ROTL(5, A) + E + W[i];
- E = D; D = C; C = ROTL(30, B); B = A; A = TEMP;
- }
-#elif SHA_CODE_SIZE == 2
- for (i = 0; i < 20; i += 5) {
- subRound( A, B, C, D, E, f1, K1, W[ i ] );
- subRound( E, A, B, C, D, f1, K1, W[ i+1 ] );
- subRound( D, E, A, B, C, f1, K1, W[ i+2 ] );
- subRound( C, D, E, A, B, f1, K1, W[ i+3 ] );
- subRound( B, C, D, E, A, f1, K1, W[ i+4 ] );
- }
- for (; i < 40; i += 5) {
- subRound( A, B, C, D, E, f2, K2, W[ i ] );
- subRound( E, A, B, C, D, f2, K2, W[ i+1 ] );
- subRound( D, E, A, B, C, f2, K2, W[ i+2 ] );
- subRound( C, D, E, A, B, f2, K2, W[ i+3 ] );
- subRound( B, C, D, E, A, f2, K2, W[ i+4 ] );
- }
- for (; i < 60; i += 5) {
- subRound( A, B, C, D, E, f3, K3, W[ i ] );
- subRound( E, A, B, C, D, f3, K3, W[ i+1 ] );
- subRound( D, E, A, B, C, f3, K3, W[ i+2 ] );
- subRound( C, D, E, A, B, f3, K3, W[ i+3 ] );
- subRound( B, C, D, E, A, f3, K3, W[ i+4 ] );
- }
- for (; i < 80; i += 5) {
- subRound( A, B, C, D, E, f4, K4, W[ i ] );
- subRound( E, A, B, C, D, f4, K4, W[ i+1 ] );
- subRound( D, E, A, B, C, f4, K4, W[ i+2 ] );
- subRound( C, D, E, A, B, f4, K4, W[ i+3 ] );
- subRound( B, C, D, E, A, f4, K4, W[ i+4 ] );
- }
-#elif SHA_CODE_SIZE == 3 /* Really large version */
- subRound( A, B, C, D, E, f1, K1, W[ 0 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 1 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 2 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 3 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 4 ] );
- subRound( A, B, C, D, E, f1, K1, W[ 5 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 6 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 7 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 8 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 9 ] );
- subRound( A, B, C, D, E, f1, K1, W[ 10 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 11 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 12 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 13 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 14 ] );
- subRound( A, B, C, D, E, f1, K1, W[ 15 ] );
- subRound( E, A, B, C, D, f1, K1, W[ 16 ] );
- subRound( D, E, A, B, C, f1, K1, W[ 17 ] );
- subRound( C, D, E, A, B, f1, K1, W[ 18 ] );
- subRound( B, C, D, E, A, f1, K1, W[ 19 ] );
-
- subRound( A, B, C, D, E, f2, K2, W[ 20 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 21 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 22 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 23 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 24 ] );
- subRound( A, B, C, D, E, f2, K2, W[ 25 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 26 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 27 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 28 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 29 ] );
- subRound( A, B, C, D, E, f2, K2, W[ 30 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 31 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 32 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 33 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 34 ] );
- subRound( A, B, C, D, E, f2, K2, W[ 35 ] );
- subRound( E, A, B, C, D, f2, K2, W[ 36 ] );
- subRound( D, E, A, B, C, f2, K2, W[ 37 ] );
- subRound( C, D, E, A, B, f2, K2, W[ 38 ] );
- subRound( B, C, D, E, A, f2, K2, W[ 39 ] );
-
- subRound( A, B, C, D, E, f3, K3, W[ 40 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 41 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 42 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 43 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 44 ] );
- subRound( A, B, C, D, E, f3, K3, W[ 45 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 46 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 47 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 48 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 49 ] );
- subRound( A, B, C, D, E, f3, K3, W[ 50 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 51 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 52 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 53 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 54 ] );
- subRound( A, B, C, D, E, f3, K3, W[ 55 ] );
- subRound( E, A, B, C, D, f3, K3, W[ 56 ] );
- subRound( D, E, A, B, C, f3, K3, W[ 57 ] );
- subRound( C, D, E, A, B, f3, K3, W[ 58 ] );
- subRound( B, C, D, E, A, f3, K3, W[ 59 ] );
-
- subRound( A, B, C, D, E, f4, K4, W[ 60 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 61 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 62 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 63 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 64 ] );
- subRound( A, B, C, D, E, f4, K4, W[ 65 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 66 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 67 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 68 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 69 ] );
- subRound( A, B, C, D, E, f4, K4, W[ 70 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 71 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 72 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 73 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 74 ] );
- subRound( A, B, C, D, E, f4, K4, W[ 75 ] );
- subRound( E, A, B, C, D, f4, K4, W[ 76 ] );
- subRound( D, E, A, B, C, f4, K4, W[ 77 ] );
- subRound( C, D, E, A, B, f4, K4, W[ 78 ] );
- subRound( B, C, D, E, A, f4, K4, W[ 79 ] );
-#else
-#error Illegal SHA_CODE_SIZE
-#endif
-
- /* Build message digest */
- digest[ 0 ] += A;
- digest[ 1 ] += B;
- digest[ 2 ] += C;
- digest[ 3 ] += D;
- digest[ 4 ] += E;
-
- /* W is wiped by the caller */
-#undef W
-}
-
-#undef ROTL
-#undef f1
-#undef f2
-#undef f3
-#undef f4
-#undef K1
-#undef K2
-#undef K3
-#undef K4
-#undef subRound
-
-#else /* !USE_SHA - Use MD5 */
-
-#define HASH_BUFFER_SIZE 4
-#define HASH_EXTRA_SIZE 0
-#define HASH_TRANSFORM MD5Transform
-
-/*
- * MD5 transform algorithm, taken from code written by Colin Plumb,
- * and put into the public domain
- */
-
-/* The four core functions - F1 is optimized somewhat */
-
-/* #define F1(x, y, z) (x & y | ~x & z) */
-#define F1(x, y, z) (z ^ (x & (y ^ z)))
-#define F2(x, y, z) F1(z, x, y)
-#define F3(x, y, z) (x ^ y ^ z)
-#define F4(x, y, z) (y ^ (x | ~z))
-
-/* This is the central step in the MD5 algorithm. */
-#define MD5STEP(f, w, x, y, z, data, s) \
- ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
-
-/*
- * The core of the MD5 algorithm, this alters an existing MD5 hash to
- * reflect the addition of 16 longwords of new data. MD5Update blocks
- * the data and converts bytes into longwords for this routine.
- */
-static void MD5Transform(__u32 buf[HASH_BUFFER_SIZE], __u32 const in[16])
-{
- __u32 a, b, c, d;
-
- a = buf[0];
- b = buf[1];
- c = buf[2];
- d = buf[3];
-
- MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478, 7);
- MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
- MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
- MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
- MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf, 7);
- MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
- MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
- MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
- MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8, 7);
- MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
- MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
- MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
- MD5STEP(F1, a, b, c, d, in[12]+0x6b901122, 7);
- MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
- MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
- MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
-
- MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562, 5);
- MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340, 9);
- MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
- MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
- MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d, 5);
- MD5STEP(F2, d, a, b, c, in[10]+0x02441453, 9);
- MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
- MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
- MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6, 5);
- MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6, 9);
- MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
- MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
- MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905, 5);
- MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8, 9);
- MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
- MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
-
- MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942, 4);
- MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
- MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
- MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
- MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44, 4);
- MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
- MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
- MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
- MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6, 4);
- MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
- MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
- MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
- MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039, 4);
- MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
- MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
- MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
-
- MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244, 6);
- MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
- MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
- MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
- MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3, 6);
- MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
- MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
- MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
- MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f, 6);
- MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
- MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
- MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
- MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82, 6);
- MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
- MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
- MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
-
- buf[0] += a;
- buf[1] += b;
- buf[2] += c;
- buf[3] += d;
-}
-
-#undef F1
-#undef F2
-#undef F3
-#undef F4
-#undef MD5STEP
-
-#endif /* !USE_SHA */
-
/*********************************************************************
*
* Entropy extraction routines
@@ -1305,169 +741,145 @@
#define EXTRACT_ENTROPY_USER 1
#define EXTRACT_ENTROPY_SECONDARY 2
#define EXTRACT_ENTROPY_LIMIT 4
-#define TMP_BUF_SIZE (HASH_BUFFER_SIZE + HASH_EXTRA_SIZE)
-#define SEC_XFER_SIZE (TMP_BUF_SIZE*4)
+#define CRYPTO_MAX_BLOCK_SIZE 32

static ssize_t extract_entropy(struct entropy_store *r, void * buf,
size_t nbytes, int flags);

+static inline void increment_iv(unsigned char *IV, const unsigned int IVsize) {
+ unsigned int i;
+ for (i=0; i<IVsize; i++) {
+ if ( ++(IV[i]) ) {
+ break;
+ }
+ }
+}
+
/*
- * This utility inline function is responsible for transfering entropy
- * from the primary pool to the secondary extraction pool. We make
- * sure we pull enough for a 'catastrophic reseed'.
- */
-static inline void xfer_secondary_pool(struct entropy_store *r,
- size_t nbytes, __u32 *tmp)
-{
- if (r->entropy_count < nbytes * 8 &&
- r->entropy_count < r->poolinfo.POOLBITS) {
- int bytes = max_t(int, random_read_wakeup_thresh / 8,
- min_t(int, nbytes, TMP_BUF_SIZE));
-
- DEBUG_ENT("%04d %04d : going to reseed %s with %d bits "
- "(%d of %d requested)\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- r == sec_random_state ? "secondary" : "unknown",
- bytes * 8, nbytes * 8, r->entropy_count);
-
- bytes=extract_entropy(random_state, tmp, bytes,
- EXTRACT_ENTROPY_LIMIT);
- add_entropy_words(r, tmp, bytes);
- credit_entropy_store(r, bytes*8);
+ * Fortuna's Reseed is ...
+ */
+static void random_reseed(struct entropy_store *r) {
+ struct scatterlist sg[1];
+ int i;
+ unsigned char tmp[RANDOM_MAX_DIGEST_SIZE];
+
+ r->reseed_count++;
+
+ crypto_digest_init(r->reseedHash);
+
+ sg[0].page = virt_to_page(r->key);
+ sg[0].offset = offset_in_page(r->key);
+ sg[0].length = r->keysize;
+ crypto_digest_update(r->reseedHash, sg, 1);
+
+#define TESTBIT(VAL, N)\
+ ( ((VAL) >> (N)) & 1 )
+ for (i=0; i<(1<<r->pool_number); i++) {
+ /* using pool[i] if r->reseed_count is divisible by 2^i
+ * since 2^0 == 1, we always use pool[0]
+ */
+ if ( (i==0) || TESTBIT(r->reseed_count,i)==0 ) {
+ crypto_digest_final(r->pools[i], tmp);
+
+ sg[0].page = virt_to_page(tmp);
+ sg[0].offset = offset_in_page(tmp);
+ sg[0].length = r->keysize;
+ crypto_digest_update(r->reseedHash, sg, 1);
+
+ crypto_digest_init(r->pools[i]);
+ /* should each pool carry it's past state forward? */
+ crypto_digest_update(r->pools[i], sg, 1);
+ } else {
+ /* pool N can only be used once every 2^N times */
+ break;
+ }
}
+#undef TESTBIT
+
+ crypto_digest_final(r->reseedHash, r->key);
+ crypto_cipher_setkey(r->cipher, r->key, r->keysize);
+ increment_iv(r->iv, r->blocksize);
}

/*
* This function extracts randomness from the "entropy pool", and
- * returns it in a buffer. This function computes how many remaining
- * bits of entropy are left in the pool, but it does not restrict the
- * number of bytes that are actually obtained. If the EXTRACT_ENTROPY_USER
+ * returns it in a buffer. If the EXTRACT_ENTROPY_USER
* flag is given, then the buf pointer is assumed to be in user space.
- *
- * If the EXTRACT_ENTROPY_SECONDARY flag is given, then we are actually
- * extracting entropy from the secondary pool, and can refill from the
- * primary pool if needed.
- *
- * Note: extract_entropy() assumes that .poolwords is a multiple of 16 words.
*/
static ssize_t extract_entropy(struct entropy_store *r, void * buf,
size_t nbytes, int flags)
{
ssize_t ret, i;
- __u32 tmp[TMP_BUF_SIZE];
- __u32 x;
+ __u32 tmp[CRYPTO_MAX_BLOCK_SIZE];
unsigned long cpuflags;
+ struct scatterlist sgiv[1],
+ sgtmp[1];

-
- /* Redundant, but just in case... */
- if (r->entropy_count > r->poolinfo.POOLBITS)
- r->entropy_count = r->poolinfo.POOLBITS;
-
- if (flags & EXTRACT_ENTROPY_SECONDARY)
- xfer_secondary_pool(r, nbytes, tmp);
-
- /* Hold lock while accounting */
+ /* lock while we're reseeding */
spin_lock_irqsave(&r->lock, cpuflags);

- DEBUG_ENT("%04d %04d : trying to extract %d bits from %s\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- nbytes * 8,
- r == sec_random_state ? "secondary" :
- r == random_state ? "primary" : "unknown");
-
- if (flags & EXTRACT_ENTROPY_LIMIT && nbytes >= r->entropy_count / 8)
- nbytes = r->entropy_count / 8;
-
- if (r->entropy_count / 8 >= nbytes)
- r->entropy_count -= nbytes*8;
- else
- r->entropy_count = 0;
+ random_reseed(r);
+ r->pool0_len = 0;

- if (r->entropy_count < random_write_wakeup_thresh)
- wake_up_interruptible(&random_write_wait);
+ spin_unlock_irqrestore(&r->lock, cpuflags);

- DEBUG_ENT("%04d %04d : debiting %d bits from %s%s\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- nbytes * 8,
- r == sec_random_state ? "secondary" :
- r == random_state ? "primary" : "unknown",
- flags & EXTRACT_ENTROPY_LIMIT ? "" : " (unlimited)");
+ /*
+ * don't output any data until we reseed at least once
+ * But this causes problems at boot-time. So weĺl assume since they
+ * don't wait to the PRNG to setup, they don't really new strong random
+ * data
+ */
+ /*
+ if (r->reseed_count == 0)
+ return 0;
+ */

- spin_unlock_irqrestore(&r->lock, cpuflags);
+ sgiv[0].page = virt_to_page(r->iv);
+ sgiv[0].offset = offset_in_page(r->iv);
+ sgiv[0].length = r->blocksize;
+ sgtmp[0].page = virt_to_page(tmp);
+ sgtmp[0].offset = offset_in_page(tmp);
+ sgtmp[0].length = r->blocksize;

ret = 0;
while (nbytes) {
- /*
- * Check if we need to break out or reschedule....
- */
- if ((flags & EXTRACT_ENTROPY_USER) && need_resched()) {
- if (signal_pending(current)) {
- if (ret == 0)
- ret = -ERESTARTSYS;
- break;
- }
+ crypto_cipher_encrypt(r->cipher, sgtmp, sgiv, r->blocksize);
+ increment_iv(r->iv, r->blocksize);

- DEBUG_ENT("%04d %04d : extract feeling sleepy (%d bytes left)\n",
- random_state->entropy_count,
- sec_random_state->entropy_count, nbytes);
-
- schedule();
-
- DEBUG_ENT("%04d %04d : extract woke up\n",
- random_state->entropy_count,
- sec_random_state->entropy_count);
- }
-
- /* Hash the pool to get the output */
- tmp[0] = 0x67452301;
- tmp[1] = 0xefcdab89;
- tmp[2] = 0x98badcfe;
- tmp[3] = 0x10325476;
-#ifdef USE_SHA
- tmp[4] = 0xc3d2e1f0;
-#endif
- /*
- * As we hash the pool, we mix intermediate values of
- * the hash back into the pool. This eliminates
- * backtracking attacks (where the attacker knows
- * the state of the pool plus the current outputs, and
- * attempts to find previous ouputs), unless the hash
- * function can be inverted.
- */
- for (i = 0, x = 0; i < r->poolinfo.poolwords; i += 16, x+=2) {
- HASH_TRANSFORM(tmp, r->pool+i);
- add_entropy_words(r, &tmp[x%HASH_BUFFER_SIZE], 1);
- }
-
- /*
- * In case the hash function has some recognizable
- * output pattern, we fold it in half.
- */
- for (i = 0; i < HASH_BUFFER_SIZE/2; i++)
- tmp[i] ^= tmp[i + (HASH_BUFFER_SIZE+1)/2];
-#if HASH_BUFFER_SIZE & 1 /* There's a middle word to deal with */
- x = tmp[HASH_BUFFER_SIZE/2];
- x ^= (x >> 16); /* Fold it in half */
- ((__u16 *)tmp)[HASH_BUFFER_SIZE-1] = (__u16)x;
-#endif
-
/* Copy data to destination buffer */
- i = min(nbytes, HASH_BUFFER_SIZE*sizeof(__u32)/2);
+ i = (nbytes < 16) ? nbytes : 16;
if (flags & EXTRACT_ENTROPY_USER) {
i -= copy_to_user(buf, (__u8 const *)tmp, i);
if (!i) {
ret = -EFAULT;
break;
}
- } else
+ } else {
memcpy(buf, (__u8 const *)tmp, i);
+ }
nbytes -= i;
buf += i;
ret += i;
}
+
+ /* generate a new key */
+ /* take into account the possibility that keysize >= blocksize */
+ for (i=0; i+r->blocksize<=r->keysize; i+=r->blocksize) {
+ sgtmp[0].page = virt_to_page( r->key+i );
+ sgtmp[0].offset = offset_in_page( r->key+i );
+ sgtmp[0].length = r->blocksize;
+ crypto_cipher_encrypt(r->cipher, sgtmp, sgiv, 1);
+ increment_iv(r->iv, r->blocksize);
+ }
+ sgtmp[0].page = virt_to_page( r->key+i );
+ sgtmp[0].offset = offset_in_page( r->key+i );
+ sgtmp[0].length = r->blocksize-i;
+ crypto_cipher_encrypt(r->cipher, sgtmp, sgiv, 1);
+ increment_iv(r->iv, r->blocksize);
+
+ if (crypto_cipher_setkey(r->cipher, r->key, r->keysize)) {
+ return -EINVAL;
+ }

/* Wipe data just returned from memory */
memset(tmp, 0, sizeof(tmp));
@@ -1482,10 +894,7 @@
*/
void get_random_bytes(void *buf, int nbytes)
{
- if (sec_random_state)
- extract_entropy(sec_random_state, (char *) buf, nbytes,
- EXTRACT_ENTROPY_SECONDARY);
- else if (random_state)
+ if (random_state)
extract_entropy(random_state, (char *) buf, nbytes, 0);
else
printk(KERN_NOTICE "get_random_bytes called before "
@@ -1500,57 +909,16 @@
*
*********************************************************************/

-/*
- * Initialize the random pool with standard stuff.
- *
- * NOTE: This is an OS-dependent function.
- */
-static void init_std_data(struct entropy_store *r)
-{
- struct timeval tv;
- __u32 words[2];
- char *p;
- int i;
-
- do_gettimeofday(&tv);
- words[0] = tv.tv_sec;
- words[1] = tv.tv_usec;
- add_entropy_words(r, words, 2);
-
- /*
- * This doesn't lock system.utsname. However, we are generating
- * entropy so a race with a name set here is fine.
- */
- p = (char *) &system_utsname;
- for (i = sizeof(system_utsname) / sizeof(words); i; i--) {
- memcpy(words, p, sizeof(words));
- add_entropy_words(r, words, sizeof(words)/4);
- p += sizeof(words);
- }
-}
-
static int __init rand_initialize(void)
{
- int i;
-
- if (create_entropy_store(DEFAULT_POOL_SIZE, &random_state))
- goto err;
- if (batch_entropy_init(BATCH_ENTROPY_SIZE, random_state))
- goto err;
- if (create_entropy_store(SECONDARY_POOL_SIZE, &sec_random_state))
+ if (create_entropy_store(DEFAULT_POOL_NUMBER, &random_state))
goto err;
- clear_entropy_store(random_state);
- clear_entropy_store(sec_random_state);
- init_std_data(random_state);
+ if (batch_entropy_init(BATCH_ENTROPY_SIZE, random_state))
+ goto err;
+
#ifdef CONFIG_SYSCTL
sysctl_init_random(random_state);
#endif
- for (i = 0; i < NR_IRQS; i++)
- irq_timer_state[i] = NULL;
- memset(&keyboard_timer_state, 0, sizeof(struct timer_rand_state));
- memset(&mouse_timer_state, 0, sizeof(struct timer_rand_state));
- memset(&extract_timer_state, 0, sizeof(struct timer_rand_state));
- extract_timer_state.dont_count_entropy = 1;
return 0;
err:
return -1;
@@ -1559,139 +927,33 @@

void rand_initialize_irq(int irq)
{
- struct timer_rand_state *state;
-
- if (irq >= NR_IRQS || irq_timer_state[irq])
- return;
-
- /*
- * If kmalloc returns null, we just won't use that entropy
- * source.
- */
- state = kmalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
- if (state) {
- memset(state, 0, sizeof(struct timer_rand_state));
- irq_timer_state[irq] = state;
- }
+ /* we don't use timers anymore, we just use the current time */
}

void rand_initialize_disk(struct gendisk *disk)
{
- struct timer_rand_state *state;
-
- /*
- * If kmalloc returns null, we just won't use that entropy
- * source.
- */
- state = kmalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
- if (state) {
- memset(state, 0, sizeof(struct timer_rand_state));
- disk->random = state;
- }
-}
-
-static ssize_t
-random_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)
-{
- DECLARE_WAITQUEUE(wait, current);
- ssize_t n, retval = 0, count = 0;
-
- if (nbytes == 0)
- return 0;
-
- while (nbytes > 0) {
- n = nbytes;
- if (n > SEC_XFER_SIZE)
- n = SEC_XFER_SIZE;
-
- DEBUG_ENT("%04d %04d : reading %d bits, p: %d s: %d\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- n*8, random_state->entropy_count,
- sec_random_state->entropy_count);
-
- n = extract_entropy(sec_random_state, buf, n,
- EXTRACT_ENTROPY_USER |
- EXTRACT_ENTROPY_LIMIT |
- EXTRACT_ENTROPY_SECONDARY);
-
- DEBUG_ENT("%04d %04d : read got %d bits (%d still needed)\n",
- random_state->entropy_count,
- sec_random_state->entropy_count,
- n*8, (nbytes-n)*8);
-
- if (n == 0) {
- if (file->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- break;
- }
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
-
- DEBUG_ENT("%04d %04d : sleeping?\n",
- random_state->entropy_count,
- sec_random_state->entropy_count);
-
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&random_read_wait, &wait);
-
- if (sec_random_state->entropy_count / 8 == 0)
- schedule();
-
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&random_read_wait, &wait);
-
- DEBUG_ENT("%04d %04d : waking up\n",
- random_state->entropy_count,
- sec_random_state->entropy_count);
-
- continue;
- }
-
- if (n < 0) {
- retval = n;
- break;
- }
- count += n;
- buf += n;
- nbytes -= n;
- break; /* This break makes the device work */
- /* like a named pipe */
- }
-
- /*
- * If we gave the user some bytes, update the access time.
- */
- if (count)
- file_accessed(file);
-
- return (count ? count : retval);
+ /* we don't use timers anymore, we just use the current time */
}

static ssize_t
urandom_read(struct file * file, char __user * buf,
size_t nbytes, loff_t *ppos)
{
- return extract_entropy(sec_random_state, buf, nbytes,
+ return extract_entropy(random_state, buf, nbytes,
EXTRACT_ENTROPY_USER |
EXTRACT_ENTROPY_SECONDARY);
}

+static ssize_t
+random_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)
+{
+ return urandom_read(file, buf, nbytes, ppos);
+}
+
static unsigned int
random_poll(struct file *file, poll_table * wait)
{
- unsigned int mask;
-
- poll_wait(file, &random_read_wait, wait);
- poll_wait(file, &random_write_wait, wait);
- mask = 0;
- if (random_state->entropy_count >= random_read_wakeup_thresh)
- mask |= POLLIN | POLLRDNORM;
- if (random_state->entropy_count < random_write_wakeup_thresh)
- mask |= POLLOUT | POLLWRNORM;
- return mask;
+ return POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
}

static ssize_t
@@ -1701,12 +963,13 @@
int ret = 0;
size_t bytes;
__u32 buf[16];
- const char __user *p = buffer;
+ const char __user *p = buffer;
size_t c = count;

while (c > 0) {
bytes = min(c, sizeof(buf));

+DEBUG_PRINTK("random_write() %p, %p, %u\n", &buf, p, bytes);
bytes -= copy_from_user(&buf, p, bytes);
if (!bytes) {
ret = -EFAULT;
@@ -1730,67 +993,25 @@
random_ioctl(struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg)
{
- int *tmp, size, ent_count;
- int __user *p = (int __user *)arg;
+ int size, ent_count;
+ int __user *p = (int __user *) arg;
int retval;
- unsigned long flags;

switch (cmd) {
case RNDGETENTCNT:
- ent_count = random_state->entropy_count;
- if (put_user(ent_count, p))
+ if (put_user(random_entropy_count, p))
return -EFAULT;
return 0;
case RNDADDTOENTCNT:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (get_user(ent_count, p))
- return -EFAULT;
- credit_entropy_store(random_state, ent_count);
- /*
- * Wake up waiting processes if we have enough
- * entropy.
- */
- if (random_state->entropy_count >= random_read_wakeup_thresh)
- wake_up_interruptible(&random_read_wait);
+ /* entropy accounting removed. */
return 0;
case RNDGETPOOL:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (get_user(size, p) ||
- put_user(random_state->poolinfo.poolwords, p++))
- return -EFAULT;
- if (size < 0)
- return -EFAULT;
- if (size > random_state->poolinfo.poolwords)
- size = random_state->poolinfo.poolwords;
-
- /* prepare to atomically snapshot pool */
-
- tmp = kmalloc(size * sizeof(__u32), GFP_KERNEL);
-
- if (!tmp)
- return -ENOMEM;
-
- spin_lock_irqsave(&random_state->lock, flags);
- ent_count = random_state->entropy_count;
- memcpy(tmp, random_state->pool, size * sizeof(__u32));
- spin_unlock_irqrestore(&random_state->lock, flags);
-
- if (!copy_to_user(p, tmp, size * sizeof(__u32))) {
- kfree(tmp);
- return -EFAULT;
- }
-
- kfree(tmp);
-
- if(put_user(ent_count, p++))
- return -EFAULT;
-
+ /* jlcooke: never get the raw pool!!! */
return 0;
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
+ p = (int *) arg;
if (get_user(ent_count, p++))
return -EFAULT;
if (ent_count < 0)
@@ -1801,25 +1022,12 @@
size, &file->f_pos);
if (retval < 0)
return retval;
- credit_entropy_store(random_state, ent_count);
- /*
- * Wake up waiting processes if we have enough
- * entropy.
- */
- if (random_state->entropy_count >= random_read_wakeup_thresh)
- wake_up_interruptible(&random_read_wait);
return 0;
case RNDZAPENTCNT:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- random_state->entropy_count = 0;
+ /* entropy accounting removed. */
return 0;
case RNDCLEARPOOL:
- /* Clear the entropy pool and associated counters. */
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- clear_entropy_store(random_state);
- init_std_data(random_state);
+ /* jlcooke: this is maddness! Never clear the entropy pool */
return 0;
default:
return -EINVAL;
@@ -1875,71 +1083,111 @@
static int min_write_thresh, max_write_thresh;
static char sysctl_bootid[16];

-/*
- * This function handles a request from the user to change the pool size
- * of the primary entropy store.
- */
-static int change_poolsize(int poolsize)
-{
- struct entropy_store *new_store, *old_store;
- int ret;
-
- if ((ret = create_entropy_store(poolsize, &new_store)))
- return ret;
-
- add_entropy_words(new_store, random_state->pool,
- random_state->poolinfo.poolwords);
- credit_entropy_store(new_store, random_state->entropy_count);
-
- sysctl_init_random(new_store);
- old_store = random_state;
- random_state = batch_work.data = new_store;
- free_entropy_store(old_store);
- return 0;
-}
-
static int proc_do_poolsize(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
- int ret;
+ int ret;

- sysctl_poolsize = random_state->poolinfo.POOLBYTES;
+ if (write) {
+ /* you can't change the poolsize, but we'll let you think
+ * you can for legacy reasons.
+ */
+ return 0;
+ }

+ sysctl_poolsize = (1<<random_state->pool_number) *
+ random_state->pools[0]->__crt_alg->cra_ctxsize;
ret = proc_dointvec(table, write, filp, buffer, lenp, ppos);
- if (ret || !write ||
- (sysctl_poolsize == random_state->poolinfo.POOLBYTES))
- return ret;

- return change_poolsize(sysctl_poolsize);
+ return ret;
}

-static int poolsize_strategy(ctl_table *table, int __user *name, int nlen,
+static int poolsize_strategy(ctl_table *table, int *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen, void **context)
{
- int len;
-
- sysctl_poolsize = random_state->poolinfo.POOLBYTES;
-
- /*
- * We only handle the write case, since the read case gets
- * handled by the default handler (and we don't care if the
- * write case happens twice; it's harmless).
+ /* you can't set a poolsize strtegy because it doesn't change in
+ * size anymore
*/
- if (newval && newlen) {
- len = newlen;
- if (len > table->maxlen)
- len = table->maxlen;
- if (copy_from_user(table->data, newval, len))
- return -EFAULT;
+ return 0;
+}
+
+static int proc_derive_seed(ctl_table *table, int write, struct file *filp,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ static unsigned char *hextab = "0123456789abcdef";
+ static unsigned int derive_count=0;
+ /* hex length of derived seed */
+ static unsigned char buf[(1<<MAXIMUM_POOL_NUMBER) *
+ RANDOM_MAX_DIGEST_SIZE *8/4];
+ unsigned long flags;
+ ctl_table fake_table;
+ unsigned char tmp[RANDOM_MAX_DIGEST_SIZE];
+ unsigned int i,j;
+ struct scatterlist sg[3];
+ int ret;
+ void *p;
+
+DEBUG_PRINTK("proc_derive_seed() 0\n");
+
+ spin_lock_irqsave(&random_state->lock, flags);
+ random_state->pool0_len = 0;
+
+ memset(buf, 0, random_state->pool_number * 2*random_state->digestsize);
+
+ /* the carry-state from pool to pool */
+ memset(tmp, 0, random_state->digestsize);
+
+ for (i=0; i<(1<<random_state->pool_number); i++) {
+ crypto_digest_init(random_state->reseedHash);
+
+ /*
+ * carry the digest from the previous output so a derive seed
+ * from a lightly seeded state is indistinguishavble from a
+ * heavily seeded one
+ */
+ p = &tmp;
+ sg[0].page = virt_to_page(p);
+ sg[0].offset = offset_in_page(p);
+ sg[0].length = sizeof(tmp);
+
+ /* finalize and digest the i-th pool */
+ crypto_digest_final(random_state->pools[i], tmp);
+ crypto_digest_init(random_state->pools[i]);
+ p = &tmp;
+ sg[1].page = virt_to_page(p);
+ sg[1].offset = offset_in_page(p);
+ sg[1].length = sizeof(tmp);
+
+ /*
+ * digest in a counter to ensure the final hash can change even if the
+ * message does not
+ */
+ p = &derive_count;
+ sg[2].page = virt_to_page(p);
+ sg[2].offset = offset_in_page(p);
+ sg[2].length = sizeof(derive_count);
+
+ crypto_digest_digest(random_state->reseedHash, sg, 3, tmp);
+ for (j=0; j<random_state->digestsize; j++) {
+ buf[2*(i*random_state->digestsize +j) ] = hextab[ (tmp[j] >> 4) & 0xf ];
+ buf[2*(i*random_state->digestsize +j)+1] = hextab[ (tmp[j] ) & 0xf ];
+ }
+ derive_count++;
}

- if (sysctl_poolsize != random_state->poolinfo.POOLBYTES)
- return change_poolsize(sysctl_poolsize);
+ spin_unlock_irqrestore(&random_state->lock, flags);

- return 0;
+ fake_table.data = buf;
+ fake_table.maxlen = (1<<random_state->pool_number) *
+ 2*random_state->digestsize;
+
+ ret = proc_dostring(&fake_table, write, filp, buffer, lenp, ppos);
+
+ return ret;
}

+
/*
* These functions is used to return both the bootid UUID, and random
* UUID. The difference is in whether table->data is NULL; if it is,
@@ -1975,7 +1223,7 @@
return proc_dostring(&fake_table, write, filp, buffer, lenp, ppos);
}

-static int uuid_strategy(ctl_table *table, int __user *name, int nlen,
+static int uuid_strategy(ctl_table *table, int *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen, void **context)
{
@@ -2011,38 +1259,41 @@
.procname = "poolsize",
.data = &sysctl_poolsize,
.maxlen = sizeof(int),
+ /* you can't change the poolsize, but we'll let you think you
+ * can for legacy reasons.
+ */
.mode = 0644,
.proc_handler = &proc_do_poolsize,
.strategy = &poolsize_strategy,
},
{
- .ctl_name = RANDOM_ENTROPY_COUNT,
- .procname = "entropy_avail",
- .maxlen = sizeof(int),
- .mode = 0444,
- .proc_handler = &proc_dointvec,
- },
+ .ctl_name = RANDOM_ENTROPY_COUNT,
+ .procname = "entropy_avail",
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
{
- .ctl_name = RANDOM_READ_THRESH,
- .procname = "read_wakeup_threshold",
- .data = &random_read_wakeup_thresh,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
- .strategy = &sysctl_intvec,
- .extra1 = &min_read_thresh,
- .extra2 = &max_read_thresh,
+ .ctl_name = RANDOM_READ_THRESH,
+ .procname = "read_wakeup_threshold",
+ .data = &random_read_wakeup_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &min_read_thresh,
+ .extra2 = &max_read_thresh,
},
{
- .ctl_name = RANDOM_WRITE_THRESH,
- .procname = "write_wakeup_threshold",
- .data = &random_write_wakeup_thresh,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
- .strategy = &sysctl_intvec,
- .extra1 = &min_write_thresh,
- .extra2 = &max_write_thresh,
+ .ctl_name = RANDOM_WRITE_THRESH,
+ .procname = "write_wakeup_threshold",
+ .data = &random_write_wakeup_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &min_write_thresh,
+ .extra2 = &max_write_thresh,
},
{
.ctl_name = RANDOM_BOOT_ID,
@@ -2061,15 +1312,25 @@
.proc_handler = &proc_do_uuid,
.strategy = &uuid_strategy,
},
+ {
+ .ctl_name = RANDOM_DERIVE_SEED,
+ .procname = "derive_seed",
+ .maxlen = MAXIMUM_POOL_NUMBER * RANDOM_MAX_DIGEST_SIZE,
+ .mode = 0400,
+ .proc_handler = &proc_derive_seed,
+ },
{ .ctl_name = 0 }
};

-static void sysctl_init_random(struct entropy_store *random_state)
+static void sysctl_init_random(struct entropy_store *r)
{
min_read_thresh = 8;
min_write_thresh = 0;
- max_read_thresh = max_write_thresh = random_state->poolinfo.POOLBITS;
- random_table[1].data = &random_state->entropy_count;
+ random_entropy_count =
+ max_read_thresh =
+ max_write_thresh = (1<<r->pool_number) *
+ r->pools[0]->__crt_alg->cra_ctxsize;
+ random_table[1].data = &random_entropy_count;
}
#endif /* CONFIG_SYSCTL */

@@ -2081,135 +1342,23 @@

/*
* TCP initial sequence number picking. This uses the random number
- * generator to pick an initial secret value. This value is hashed
- * along with the TCP endpoint information to provide a unique
- * starting point for each pair of TCP endpoints. This defeats
- * attacks which rely on guessing the initial TCP sequence number.
- * This algorithm was suggested by Steve Bellovin.
+ * generator to pick an initial secret value. This value is encrypted
+ * with the TCP endpoint information to provide a unique starting point
+ * for each pair of TCP endpoints. This defeats attacks which rely on
+ * guessing the initial TCP sequence number.
*
* Using a very strong hash was taking an appreciable amount of the total
- * TCP connection establishment time, so this is a weaker hash,
- * compensated for by changing the secret periodically.
+ * TCP connection establishment time, so this now uses AES256
+ *
+ * openssl spped md4 aes shows aes256 is 2.5 times faster then basic md4 for
+ * the block sizes we're dealing with.
+ * type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes
+ * md4 10708.72k 38240.96k 111170.47k 215872.85k 296828.93k
+ * aes-128 cbc 32121.81k 32678.31k 33119.49k 33221.29k 33210.59k
+ * aes-192 cbc 27915.92k 27868.52k 28418.08k 28677.12k 28721.15k
+ * aes-256 cbc 24599.57k 25142.38k 25381.80k 25474.88k 25392.46k
*/

-/* F, G and H are basic MD4 functions: selection, majority, parity */
-#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
-#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z)))
-#define H(x, y, z) ((x) ^ (y) ^ (z))
-
-/*
- * The generic round function. The application is so specific that
- * we don't bother protecting all the arguments with parens, as is generally
- * good macro practice, in favor of extra legibility.
- * Rotation is separate from addition to prevent recomputation
- */
-#define ROUND(f, a, b, c, d, x, s) \
- (a += f(b, c, d) + x, a = (a << s) | (a >> (32-s)))
-#define K1 0
-#define K2 013240474631UL
-#define K3 015666365641UL
-
-/*
- * Basic cut-down MD4 transform. Returns only 32 bits of result.
- */
-static __u32 halfMD4Transform (__u32 const buf[4], __u32 const in[8])
-{
- __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
-
- /* Round 1 */
- ROUND(F, a, b, c, d, in[0] + K1, 3);
- ROUND(F, d, a, b, c, in[1] + K1, 7);
- ROUND(F, c, d, a, b, in[2] + K1, 11);
- ROUND(F, b, c, d, a, in[3] + K1, 19);
- ROUND(F, a, b, c, d, in[4] + K1, 3);
- ROUND(F, d, a, b, c, in[5] + K1, 7);
- ROUND(F, c, d, a, b, in[6] + K1, 11);
- ROUND(F, b, c, d, a, in[7] + K1, 19);
-
- /* Round 2 */
- ROUND(G, a, b, c, d, in[1] + K2, 3);
- ROUND(G, d, a, b, c, in[3] + K2, 5);
- ROUND(G, c, d, a, b, in[5] + K2, 9);
- ROUND(G, b, c, d, a, in[7] + K2, 13);
- ROUND(G, a, b, c, d, in[0] + K2, 3);
- ROUND(G, d, a, b, c, in[2] + K2, 5);
- ROUND(G, c, d, a, b, in[4] + K2, 9);
- ROUND(G, b, c, d, a, in[6] + K2, 13);
-
- /* Round 3 */
- ROUND(H, a, b, c, d, in[3] + K3, 3);
- ROUND(H, d, a, b, c, in[7] + K3, 9);
- ROUND(H, c, d, a, b, in[2] + K3, 11);
- ROUND(H, b, c, d, a, in[6] + K3, 15);
- ROUND(H, a, b, c, d, in[1] + K3, 3);
- ROUND(H, d, a, b, c, in[5] + K3, 9);
- ROUND(H, c, d, a, b, in[0] + K3, 11);
- ROUND(H, b, c, d, a, in[4] + K3, 15);
-
- return buf[1] + b; /* "most hashed" word */
- /* Alternative: return sum of all words? */
-}
-
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-
-static __u32 twothirdsMD4Transform (__u32 const buf[4], __u32 const in[12])
-{
- __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
-
- /* Round 1 */
- ROUND(F, a, b, c, d, in[ 0] + K1, 3);
- ROUND(F, d, a, b, c, in[ 1] + K1, 7);
- ROUND(F, c, d, a, b, in[ 2] + K1, 11);
- ROUND(F, b, c, d, a, in[ 3] + K1, 19);
- ROUND(F, a, b, c, d, in[ 4] + K1, 3);
- ROUND(F, d, a, b, c, in[ 5] + K1, 7);
- ROUND(F, c, d, a, b, in[ 6] + K1, 11);
- ROUND(F, b, c, d, a, in[ 7] + K1, 19);
- ROUND(F, a, b, c, d, in[ 8] + K1, 3);
- ROUND(F, d, a, b, c, in[ 9] + K1, 7);
- ROUND(F, c, d, a, b, in[10] + K1, 11);
- ROUND(F, b, c, d, a, in[11] + K1, 19);
-
- /* Round 2 */
- ROUND(G, a, b, c, d, in[ 1] + K2, 3);
- ROUND(G, d, a, b, c, in[ 3] + K2, 5);
- ROUND(G, c, d, a, b, in[ 5] + K2, 9);
- ROUND(G, b, c, d, a, in[ 7] + K2, 13);
- ROUND(G, a, b, c, d, in[ 9] + K2, 3);
- ROUND(G, d, a, b, c, in[11] + K2, 5);
- ROUND(G, c, d, a, b, in[ 0] + K2, 9);
- ROUND(G, b, c, d, a, in[ 2] + K2, 13);
- ROUND(G, a, b, c, d, in[ 4] + K2, 3);
- ROUND(G, d, a, b, c, in[ 6] + K2, 5);
- ROUND(G, c, d, a, b, in[ 8] + K2, 9);
- ROUND(G, b, c, d, a, in[10] + K2, 13);
-
- /* Round 3 */
- ROUND(H, a, b, c, d, in[ 3] + K3, 3);
- ROUND(H, d, a, b, c, in[ 7] + K3, 9);
- ROUND(H, c, d, a, b, in[11] + K3, 11);
- ROUND(H, b, c, d, a, in[ 2] + K3, 15);
- ROUND(H, a, b, c, d, in[ 6] + K3, 3);
- ROUND(H, d, a, b, c, in[10] + K3, 9);
- ROUND(H, c, d, a, b, in[ 1] + K3, 11);
- ROUND(H, b, c, d, a, in[ 5] + K3, 15);
- ROUND(H, a, b, c, d, in[ 9] + K3, 3);
- ROUND(H, d, a, b, c, in[ 0] + K3, 9);
- ROUND(H, c, d, a, b, in[ 4] + K3, 11);
- ROUND(H, b, c, d, a, in[ 8] + K3, 15);
-
- return buf[1] + b; /* "most hashed" word */
- /* Alternative: return sum of all words? */
-}
-#endif
-
-#undef ROUND
-#undef F
-#undef G
-#undef H
-#undef K1
-#undef K2
-#undef K3

/* This should not be decreased so low that ISNs wrap too fast. */
#define REKEY_INTERVAL 300
@@ -2237,79 +1386,70 @@
#define HASH_BITS 24
#define HASH_MASK ( (1<<HASH_BITS)-1 )

-static struct keydata {
- time_t rekey_time;
- __u32 count; // already shifted to the final position
- __u32 secret[12];
-} ____cacheline_aligned ip_keydata[2];
-
static spinlock_t ip_lock = SPIN_LOCK_UNLOCKED;
-static unsigned int ip_cnt;

-static struct keydata *__check_and_rekey(time_t time)
+static __u32 network_random_read32(void)
{
- struct keydata *keyptr;
+ static u8 ctr[16]; /* max block size? */
+ static struct scatterlist sgctr[1];
+ static unsigned int master_count=0;
+ static time_t lastRekey=0;
+
+ struct scatterlist sgtmp[1];
+ unsigned int count;
+ unsigned char tmp[16];
+ struct timeval tv;
+
+ rmb();
spin_lock_bh(&ip_lock);
- keyptr = &ip_keydata[ip_cnt&1];
- if (!keyptr->rekey_time || (time - keyptr->rekey_time) > REKEY_INTERVAL) {
- keyptr = &ip_keydata[1^(ip_cnt&1)];
- keyptr->rekey_time = time;
- get_random_bytes(keyptr->secret, sizeof(keyptr->secret));
- keyptr->count = (ip_cnt&COUNT_MASK)<<HASH_BITS;
+
+ count = ++master_count;
+ increment_iv(ctr, random_state->blocksize);
+
+ do_gettimeofday(&tv);
+ if (lastRekey==0 || (tv.tv_sec - lastRekey) < REKEY_INTERVAL) {
+ lastRekey = tv.tv_sec;
+
+ sgctr[0].page = virt_to_page(ctr);
+ sgctr[0].offset = offset_in_page(ctr);
+ sgctr[0].length = 16;
+
+ if (!random_state->networkCipher_ready) {
+ u8 secret[32]; /* max key size? */
+ get_random_bytes(secret, random_state->keysize);
+ crypto_cipher_setkey(random_state->networkCipher,
+ (const u8*)secret,
+ random_state->keysize);
+ random_state->networkCipher_ready = 1;
+ }
+
mb();
- ip_cnt++;
- }
- spin_unlock_bh(&ip_lock);
- return keyptr;
-}
+ }

-static inline struct keydata *check_and_rekey(time_t time)
-{
- struct keydata *keyptr = &ip_keydata[ip_cnt&1];
+ spin_unlock_bh(&ip_lock);

- rmb();
- if (!keyptr->rekey_time || (time - keyptr->rekey_time) > REKEY_INTERVAL) {
- keyptr = __check_and_rekey(time);
- }
+ sgtmp[0].page = virt_to_page(tmp);
+ sgtmp[0].offset = offset_in_page(tmp);
+ sgtmp[0].length = random_state->blocksize;
+ /* tmp[]/sg[0] = Enc(Sec, CTR++) */
+ crypto_cipher_encrypt(random_state->networkCipher, sgtmp, sgctr, 1);
+ increment_iv(ctr, random_state->blocksize);

- return keyptr;
+ /* seq# needs to be random-ish, but incresing */
+ return (tmp[0] & COUNT_MASK) + (count << (32-COUNT_BITS));
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
__u32 secure_tcpv6_sequence_number(__u32 *saddr, __u32 *daddr,
__u16 sport, __u16 dport)
{
- struct timeval tv;
- __u32 seq;
- __u32 hash[12];
- struct keydata *keyptr;
-
- /* The procedure is the same as for IPv4, but addresses are longer.
- * Thus we must use twothirdsMD4Transform.
- */
-
- do_gettimeofday(&tv); /* We need the usecs below... */
- keyptr = check_and_rekey(tv.tv_sec);
-
- memcpy(hash, saddr, 16);
- hash[4]=(sport << 16) + dport;
- memcpy(&hash[5],keyptr->secret,sizeof(__u32)*7);
-
- seq = twothirdsMD4Transform(daddr, hash) & HASH_MASK;
- seq += keyptr->count;
- seq += tv.tv_usec + tv.tv_sec*1000000;
-
- return seq;
+ return network_random_read32();
}
EXPORT_SYMBOL(secure_tcpv6_sequence_number);

__u32 secure_ipv6_id(__u32 *daddr)
{
- struct keydata *keyptr;
-
- keyptr = check_and_rekey(get_seconds());
-
- return halfMD4Transform(daddr, keyptr->secret);
+ return network_random_read32();
}

EXPORT_SYMBOL(secure_ipv6_id);
@@ -2319,75 +1459,20 @@
__u32 secure_tcp_sequence_number(__u32 saddr, __u32 daddr,
__u16 sport, __u16 dport)
{
- struct timeval tv;
- __u32 seq;
- __u32 hash[4];
- struct keydata *keyptr;
-
- /*
- * Pick a random secret every REKEY_INTERVAL seconds.
- */
- do_gettimeofday(&tv); /* We need the usecs below... */
- keyptr = check_and_rekey(tv.tv_sec);
-
- /*
- * Pick a unique starting offset for each TCP connection endpoints
- * (saddr, daddr, sport, dport).
- * Note that the words are placed into the starting vector, which is
- * then mixed with a partial MD4 over random data.
- */
- hash[0]=saddr;
- hash[1]=daddr;
- hash[2]=(sport << 16) + dport;
- hash[3]=keyptr->secret[11];
-
- seq = halfMD4Transform(hash, keyptr->secret) & HASH_MASK;
- seq += keyptr->count;
- /*
- * As close as possible to RFC 793, which
- * suggests using a 250 kHz clock.
- * Further reading shows this assumes 2 Mb/s networks.
- * For 10 Mb/s Ethernet, a 1 MHz clock is appropriate.
- * That's funny, Linux has one built in! Use it!
- * (Networks are faster now - should this be increased?)
- */
- seq += tv.tv_usec + tv.tv_sec*1000000;
-#if 0
- printk("init_seq(%lx, %lx, %d, %d) = %d\n",
- saddr, daddr, sport, dport, seq);
-#endif
- return seq;
+ return network_random_read32();
}

EXPORT_SYMBOL(secure_tcp_sequence_number);

-/* The code below is shamelessly stolen from secure_tcp_sequence_number().
- * All blames to Andrey V. Savochkin <saw@msu.ru>.
- */
__u32 secure_ip_id(__u32 daddr)
{
- struct keydata *keyptr;
- __u32 hash[4];
-
- keyptr = check_and_rekey(get_seconds());
-
- /*
- * Pick a unique starting offset for each IP destination.
- * The dest ip address is placed in the starting vector,
- * which is then hashed with random data.
- */
- hash[0] = daddr;
- hash[1] = keyptr->secret[9];
- hash[2] = keyptr->secret[10];
- hash[3] = keyptr->secret[11];
-
- return halfMD4Transform(hash, keyptr->secret);
+ return network_random_read32();
}

#ifdef CONFIG_SYN_COOKIES
/*
* Secure SYN cookie computation. This is the algorithm worked out by
- * Dan Bernstein and Eric Schenk.
+ * Jean-Luc Cooke
*
* For linux I implement the 1 minute counter by looking at the jiffies clock.
* The count is passed in as a parameter, so this code doesn't much care.
@@ -2396,50 +1481,54 @@
#define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)

-static int syncookie_init;
-static __u32 syncookie_secret[2][16-3+HASH_BUFFER_SIZE];
-
__u32 secure_tcp_syn_cookie(__u32 saddr, __u32 daddr, __u16 sport,
__u16 dport, __u32 sseq, __u32 count, __u32 data)
{
- __u32 tmp[16 + HASH_BUFFER_SIZE + HASH_EXTRA_SIZE];
- __u32 seq;
-
- /*
- * Pick two random secrets the first time we need a cookie.
- */
- if (syncookie_init == 0) {
- get_random_bytes(syncookie_secret, sizeof(syncookie_secret));
- syncookie_init = 1;
- }
+ struct scatterlist sg[1];
+ __u32 tmp[4];

/*
* Compute the secure sequence number.
- * The output should be:
- * HASH(sec1,saddr,sport,daddr,dport,sec1) + sseq + (count * 2^24)
- * + (HASH(sec2,saddr,sport,daddr,dport,count,sec2) % 2^24).
- * Where sseq is their sequence number and count increases every
- * minute by 1.
- * As an extra hack, we add a small "data" value that encodes the
- * MSS into the second hash value.
+ *
+ * Output is the 32bit tag of a CBC-MAC of PT={count,0,0,0} with IV={addr,daddr,sport|dport,sseq}
+ * cookie = <8bit count> || truncate_24bit( Encrypt(Sec, {saddr,daddr,sport|dport,sseq}) )
+ *
+ * DJB wrote (http://cr.yp.to/syncookies/archive) about how to do this with hash algorithms
+ * - we can replace two SHA1s used in the previous kernel with two AESs and make things 3x faster
+ * - I'd like to propose we remove the use of two whittenings with a single operation since we
+ * were only using addition modulo 2^32 of all these values anyways. Not to mention the hashs
+ * differ only in that the second processes more data... why drop the first hash? We did learn
+ * that addition is commutative and associative long ago.
+ * - by replacing two SHA1s and addition modulo 2^32 with encryption of a 32bit value using AES-CTR
+ * we've made it 1,000,000,000 times easier to understand what is going on.
+ * - Todo: we should rekey the cipher peridoically... if we do this, some packets will now fail
+ * our checking system... is this ok? How can we get around this? Rekey's would ideally happen
+ * once per minute (6 million TCP connections per minute is a unrealistic enough security margin)
*/

- memcpy(tmp+3, syncookie_secret[0], sizeof(syncookie_secret[0]));
- tmp[0]=saddr;
- tmp[1]=daddr;
- tmp[2]=(sport << 16) + dport;
- HASH_TRANSFORM(tmp+16, tmp);
- seq = tmp[17] + sseq + (count << COOKIEBITS);
-
- memcpy(tmp+3, syncookie_secret[1], sizeof(syncookie_secret[1]));
- tmp[0]=saddr;
- tmp[1]=daddr;
- tmp[2]=(sport << 16) + dport;
- tmp[3] = count; /* minute counter */
- HASH_TRANSFORM(tmp+16, tmp);
+ tmp[0] = saddr;
+ tmp[1] = daddr;
+ tmp[2] = (sport << 16) + dport;
+ tmp[3] = sseq;
+
+ sg[0].page = virt_to_page(tmp);
+ sg[0].offset = offset_in_page(tmp);
+ sg[0].length = 16;
+ if (!random_state->networkCipher_ready) {
+ u8 secret[32];
+ get_random_bytes(secret, sizeof(secret));
+ if (crypto_cipher_setkey(random_state->networkCipher,
+ secret, random_state->keysize)) {
+ return 0;
+ }
+ random_state->networkCipher_ready = 1;
+ }
+ /* tmp[]/sg[0] = Enc(Sec, {saddr,daddr,sport|dport,sseq}) */
+ crypto_cipher_encrypt(random_state->networkCipher, sg, sg, 1);

- /* Add in the second hash and the data */
- return seq + ((tmp[17] + data) & COOKIEMASK);
+ /* cookie = CTR encrypt of 8-bit-count and 24-bit-data */
+ return tmp[0] ^ ( (count << COOKIEBITS) |
+ (data >> (sizeof(__u32)*8-COOKIEBITS)) );
}

/*
@@ -2454,32 +1543,32 @@
__u32 check_tcp_syn_cookie(__u32 cookie, __u32 saddr, __u32 daddr, __u16 sport,
__u16 dport, __u32 sseq, __u32 count, __u32 maxdiff)
{
- __u32 tmp[16 + HASH_BUFFER_SIZE + HASH_EXTRA_SIZE];
- __u32 diff;
+ struct scatterlist sg[1];
+ __u32 tmp[4], thiscount, diff;

- if (syncookie_init == 0)
+ if (random_state == NULL || !random_state->networkCipher_ready)
return (__u32)-1; /* Well, duh! */

- /* Strip away the layers from the cookie */
- memcpy(tmp+3, syncookie_secret[0], sizeof(syncookie_secret[0]));
- tmp[0]=saddr;
- tmp[1]=daddr;
- tmp[2]=(sport << 16) + dport;
- HASH_TRANSFORM(tmp+16, tmp);
- cookie -= tmp[17] + sseq;
- /* Cookie is now reduced to (count * 2^24) ^ (hash % 2^24) */
-
- diff = (count - (cookie >> COOKIEBITS)) & ((__u32)-1 >> COOKIEBITS);
- if (diff >= maxdiff)
- return (__u32)-1;
-
- memcpy(tmp+3, syncookie_secret[1], sizeof(syncookie_secret[1]));
tmp[0] = saddr;
tmp[1] = daddr;
tmp[2] = (sport << 16) + dport;
- tmp[3] = count - diff; /* minute counter */
- HASH_TRANSFORM(tmp+16, tmp);
+ tmp[3] = sseq;
+ sg[0].page = virt_to_page(tmp);
+ sg[0].offset = offset_in_page(tmp);
+ sg[0].length = 16;
+ crypto_cipher_encrypt(random_state->networkCipher, sg, sg, 1);
+
+ /* CTR decrypt the cookie */
+ cookie ^= tmp[0];
+
+ /* top 8 bits are 'count' */
+ thiscount = cookie >> COOKIEBITS;
+
+ diff = count - thiscount;
+ if (diff >= maxdiff)
+ return (__u32)-1;

- return (cookie - tmp[17]) & COOKIEMASK; /* Leaving the data behind */
+ /* bottom 24 bits are 'data' */
+ return cookie >> (sizeof(__u32)*8-COOKIEBITS);
}
#endif