#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/interrupt.h>
+#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/percpu.h>
#include <linux/cryptohash.h>
+#include <linux/fips.h>
+
+#ifdef CONFIG_GENERIC_HARDIRQS
+# include <linux/irq.h>
+#endif
#include <asm/processor.h>
#include <asm/uaccess.h>
#define INPUT_POOL_WORDS 128
#define OUTPUT_POOL_WORDS 32
#define SEC_XFER_SIZE 512
+#define EXTRACT_SIZE 10
/*
* The minimum number of bits of entropy before we wake up a read on
*/
static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
+static struct fasync_struct *fasync;
#if 0
static int debug;
struct poolinfo *poolinfo;
__u32 *pool;
const char *name;
- int limit;
struct entropy_store *pull;
+ int limit;
/* read-write data: */
spinlock_t lock;
unsigned add_ptr;
int entropy_count;
int input_rotate;
+ __u8 last_data[EXTRACT_SIZE];
};
static __u32 input_pool_data[INPUT_POOL_WORDS];
};
/*
- * This function adds a byte into the entropy "pool". It does not
+ * This function adds bytes into the entropy "pool". It does not
* update the entropy estimate. The caller should call
- * credit_entropy_store if this is appropriate.
+ * credit_entropy_bits 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, __u32 out[16])
+static void mix_pool_bytes_extract(struct entropy_store *r, const void *in,
+ int nbytes, __u8 out[64])
{
static __u32 const twist_table[8] = {
0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
- unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
+ unsigned long i, j, tap1, tap2, tap3, tap4, tap5;
int input_rotate;
int wordmask = r->poolinfo->poolwords - 1;
- __u32 w, next_w;
+ const char *bytes = in;
+ __u32 w;
unsigned long flags;
/* Taps are constant, so we can load them without holding r->lock. */
tap3 = r->poolinfo->tap3;
tap4 = r->poolinfo->tap4;
tap5 = r->poolinfo->tap5;
- next_w = *in++;
spin_lock_irqsave(&r->lock, flags);
- prefetch_range(r->pool, wordmask);
input_rotate = r->input_rotate;
- add_ptr = r->add_ptr;
+ i = r->add_ptr;
- while (nwords--) {
- w = rol32(next_w, input_rotate & 31);
- if (nwords > 0)
- next_w = *in++;
- i = add_ptr = (add_ptr - 1) & wordmask;
+ /* mix one byte at a time to simplify size handling and churn faster */
+ while (nbytes--) {
+ w = rol32(*bytes++, input_rotate & 31);
+ i = (i - 1) & wordmask;
/* XOR in the various taps */
+ w ^= r->pool[i];
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];
+
+ /* Mix the result back in with a twist */
r->pool[i] = (w >> 3) ^ twist_table[w & 7];
/*
}
r->input_rotate = input_rotate;
- r->add_ptr = add_ptr;
+ r->add_ptr = i;
- if (out) {
- for (i = 0; i < 16; i++) {
- out[i] = r->pool[add_ptr];
- add_ptr = (add_ptr - 1) & wordmask;
- }
- }
+ if (out)
+ for (j = 0; j < 16; j++)
+ ((__u32 *)out)[j] = r->pool[(i - j) & wordmask];
spin_unlock_irqrestore(&r->lock, flags);
}
-static inline void add_entropy_words(struct entropy_store *r, const __u32 *in,
- int nwords)
+static void mix_pool_bytes(struct entropy_store *r, const void *in, int bytes)
{
- __add_entropy_words(r, in, nwords, NULL);
+ mix_pool_bytes_extract(r, in, bytes, NULL);
}
/*
* Credit (or debit) the entropy store with n bits of entropy
*/
-static void credit_entropy_store(struct entropy_store *r, int nbits)
+static void credit_entropy_bits(struct entropy_store *r, int nbits)
{
unsigned long flags;
+ int entropy_count;
+
+ if (!nbits)
+ 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("added %d entropy credits to %s\n",
- nbits, r->name);
- }
+ DEBUG_ENT("added %d entropy credits to %s\n", nbits, r->name);
+ entropy_count = r->entropy_count;
+ entropy_count += nbits;
+ if (entropy_count < 0) {
+ DEBUG_ENT("negative entropy/overflow\n");
+ entropy_count = 0;
+ } else if (entropy_count > r->poolinfo->POOLBITS)
+ entropy_count = r->poolinfo->POOLBITS;
+ r->entropy_count = entropy_count;
/* should we wake readers? */
- if (r == &input_pool && r->entropy_count >= random_read_wakeup_thresh)
+ if (r == &input_pool && entropy_count >= random_read_wakeup_thresh) {
wake_up_interruptible(&random_read_wait);
-
+ kill_fasync(&fasync, SIGIO, POLL_IN);
+ }
spin_unlock_irqrestore(&r->lock, flags);
}
unsigned dont_count_entropy:1;
};
-static struct timer_rand_state input_timer_state;
+#ifndef CONFIG_GENERIC_HARDIRQS
+
static struct timer_rand_state *irq_timer_state[NR_IRQS];
+static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
+{
+ return irq_timer_state[irq];
+}
+
+static void set_timer_rand_state(unsigned int irq,
+ struct timer_rand_state *state)
+{
+ irq_timer_state[irq] = state;
+}
+
+#else
+
+static struct timer_rand_state *get_timer_rand_state(unsigned int irq)
+{
+ struct irq_desc *desc;
+
+ desc = irq_to_desc(irq);
+
+ return desc->timer_rand_state;
+}
+
+static void set_timer_rand_state(unsigned int irq,
+ struct timer_rand_state *state)
+{
+ struct irq_desc *desc;
+
+ desc = irq_to_desc(irq);
+
+ desc->timer_rand_state = state;
+}
+#endif
+
+static struct timer_rand_state input_timer_state;
+
/*
* This function adds entropy to the entropy "pool" by using timing
* delays. It uses the timer_rand_state structure to make an estimate
preempt_disable();
/* if over the trickle threshold, use only 1 in 4096 samples */
if (input_pool.entropy_count > trickle_thresh &&
- (__get_cpu_var(trickle_count)++ & 0xfff))
+ ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff))
goto out;
sample.jiffies = jiffies;
sample.cycles = get_cycles();
sample.num = num;
- add_entropy_words(&input_pool, (u32 *)&sample, sizeof(sample)/4);
+ mix_pool_bytes(&input_pool, &sample, sizeof(sample));
/*
* Calculate number of bits of randomness we probably added.
* Round down by 1 bit on general principles,
* and limit entropy entimate to 12 bits.
*/
- credit_entropy_store(&input_pool,
- min_t(int, fls(delta>>1), 11));
+ credit_entropy_bits(&input_pool,
+ min_t(int, fls(delta>>1), 11));
}
out:
preempt_enable();
void add_interrupt_randomness(int irq)
{
- if (irq >= NR_IRQS || irq_timer_state[irq] == NULL)
+ struct timer_rand_state *state;
+
+ state = get_timer_rand_state(irq);
+
+ if (state == NULL)
return;
DEBUG_ENT("irq event %d\n", irq);
- add_timer_randomness(irq_timer_state[irq], 0x100 + irq);
+ add_timer_randomness(state, 0x100 + irq);
}
#ifdef CONFIG_BLOCK
if (!disk || !disk->random)
return;
/* first major is 1, so we get >= 0x200 here */
- DEBUG_ENT("disk event %d:%d\n", disk->major, disk->first_minor);
+ DEBUG_ENT("disk event %d:%d\n",
+ MAJOR(disk_devt(disk)), MINOR(disk_devt(disk)));
- add_timer_randomness(disk->random,
- 0x100 + MKDEV(disk->major, disk->first_minor));
+ add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
}
#endif
-#define EXTRACT_SIZE 10
-
/*********************************************************************
*
* Entropy extraction routines
bytes = extract_entropy(r->pull, tmp, bytes,
random_read_wakeup_thresh / 8, rsvd);
- add_entropy_words(r, tmp, (bytes + 3) / 4);
- credit_entropy_store(r, bytes*8);
+ mix_pool_bytes(r, tmp, bytes);
+ credit_entropy_bits(r, bytes*8);
}
}
{
unsigned long flags;
- BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);
-
/* Hold lock while accounting */
spin_lock_irqsave(&r->lock, flags);
+ BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);
DEBUG_ENT("trying to extract %d bits from %s\n",
nbytes * 8, r->name);
else
r->entropy_count = reserved;
- if (r->entropy_count < random_write_wakeup_thresh)
+ if (r->entropy_count < random_write_wakeup_thresh) {
wake_up_interruptible(&random_write_wait);
+ kill_fasync(&fasync, SIGIO, POLL_OUT);
+ }
}
DEBUG_ENT("debiting %d entropy credits from %s%s\n",
static void extract_buf(struct entropy_store *r, __u8 *out)
{
int i;
- __u32 extract[16], hash[5], workspace[SHA_WORKSPACE_WORDS];
+ __u32 hash[5], workspace[SHA_WORKSPACE_WORDS];
+ __u8 extract[64];
/* Generate a hash across the pool, 16 words (512 bits) at a time */
sha_init(hash);
* brute-forcing the feedback as hard as brute-forcing the
* hash.
*/
- __add_entropy_words(r, hash, 5, extract);
+ mix_pool_bytes_extract(r, hash, sizeof(hash), extract);
/*
* To avoid duplicates, we atomically extract a portion of the
* pool while mixing, and hash one final time.
*/
- sha_transform(hash, (__u8 *)extract, workspace);
+ sha_transform(hash, extract, workspace);
memset(extract, 0, sizeof(extract));
memset(workspace, 0, sizeof(workspace));
{
ssize_t ret = 0, i;
__u8 tmp[EXTRACT_SIZE];
+ unsigned long flags;
xfer_secondary_pool(r, nbytes);
nbytes = account(r, nbytes, min, reserved);
while (nbytes) {
extract_buf(r, tmp);
+
+ if (fips_enabled) {
+ spin_lock_irqsave(&r->lock, flags);
+ if (!memcmp(tmp, r->last_data, EXTRACT_SIZE))
+ panic("Hardware RNG duplicated output!\n");
+ memcpy(r->last_data, tmp, EXTRACT_SIZE);
+ spin_unlock_irqrestore(&r->lock, flags);
+ }
i = min_t(int, nbytes, EXTRACT_SIZE);
memcpy(buf, tmp, i);
nbytes -= i;
spin_unlock_irqrestore(&r->lock, flags);
now = ktime_get_real();
- add_entropy_words(r, (__u32 *)&now, sizeof(now)/4);
- add_entropy_words(r, (__u32 *)utsname(),
- sizeof(*(utsname()))/4);
+ mix_pool_bytes(r, &now, sizeof(now));
+ mix_pool_bytes(r, utsname(), sizeof(*(utsname())));
}
static int rand_initialize(void)
{
struct timer_rand_state *state;
- if (irq >= NR_IRQS || irq_timer_state[irq])
+ state = get_timer_rand_state(irq);
+
+ if (state)
return;
/*
*/
state = kzalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
if (state)
- irq_timer_state[irq] = state;
+ set_timer_rand_state(irq, state);
}
#ifdef CONFIG_BLOCK
/* like a named pipe */
}
- /*
- * If we gave the user some bytes, update the access time.
- */
- if (count)
- file_accessed(file);
-
return (count ? count : retval);
}
count -= bytes;
p += bytes;
- add_entropy_words(r, buf, (bytes + 3) / 4);
+ mix_pool_bytes(r, buf, bytes);
cond_resched();
}
size_t count, loff_t *ppos)
{
size_t ret;
- struct inode *inode = file->f_path.dentry->d_inode;
ret = write_pool(&blocking_pool, buffer, count);
if (ret)
if (ret)
return ret;
- inode->i_mtime = current_fs_time(inode->i_sb);
- mark_inode_dirty(inode);
return (ssize_t)count;
}
return -EPERM;
if (get_user(ent_count, p))
return -EFAULT;
- credit_entropy_store(&input_pool, ent_count);
+ credit_entropy_bits(&input_pool, ent_count);
return 0;
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
size);
if (retval < 0)
return retval;
- credit_entropy_store(&input_pool, ent_count);
+ credit_entropy_bits(&input_pool, ent_count);
return 0;
case RNDZAPENTCNT:
case RNDCLEARPOOL:
}
}
+static int random_fasync(int fd, struct file *filp, int on)
+{
+ return fasync_helper(fd, filp, on, &fasync);
+}
+
const struct file_operations random_fops = {
.read = random_read,
.write = random_write,
.poll = random_poll,
.unlocked_ioctl = random_ioctl,
+ .fasync = random_fasync,
+ .llseek = noop_llseek,
};
const struct file_operations urandom_fops = {
.read = urandom_read,
.write = random_write,
.unlocked_ioctl = random_ioctl,
+ .fasync = random_fasync,
+ .llseek = noop_llseek,
};
/***************************************************************
void generate_random_uuid(unsigned char uuid_out[16])
{
get_random_bytes(uuid_out, 16);
- /* Set UUID version to 4 --- truely random generation */
+ /* Set UUID version to 4 --- truly random generation */
uuid_out[6] = (uuid_out[6] & 0x0F) | 0x40;
/* Set the UUID variant to DCE */
uuid_out[8] = (uuid_out[8] & 0x3F) | 0x80;
* as an ASCII string in the standard UUID format. If accesses via the
* sysctl system call, it is returned as 16 bytes of binary data.
*/
-static int proc_do_uuid(ctl_table *table, int write, struct file *filp,
+static int proc_do_uuid(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
ctl_table fake_table;
if (uuid[8] == 0)
generate_random_uuid(uuid);
- sprintf(buf, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-"
- "%02x%02x%02x%02x%02x%02x",
- uuid[0], uuid[1], uuid[2], uuid[3],
- uuid[4], uuid[5], uuid[6], uuid[7],
- uuid[8], uuid[9], uuid[10], uuid[11],
- uuid[12], uuid[13], uuid[14], uuid[15]);
+ sprintf(buf, "%pU", uuid);
+
fake_table.data = buf;
fake_table.maxlen = sizeof(buf);
- return proc_dostring(&fake_table, write, filp, buffer, lenp, ppos);
-}
-
-static int uuid_strategy(ctl_table *table, int __user *name, int nlen,
- void __user *oldval, size_t __user *oldlenp,
- void __user *newval, size_t newlen)
-{
- unsigned char tmp_uuid[16], *uuid;
- unsigned int len;
-
- if (!oldval || !oldlenp)
- return 1;
-
- uuid = table->data;
- if (!uuid) {
- uuid = tmp_uuid;
- uuid[8] = 0;
- }
- if (uuid[8] == 0)
- generate_random_uuid(uuid);
-
- if (get_user(len, oldlenp))
- return -EFAULT;
- if (len) {
- if (len > 16)
- len = 16;
- if (copy_to_user(oldval, uuid, len) ||
- put_user(len, oldlenp))
- return -EFAULT;
- }
- return 1;
+ return proc_dostring(&fake_table, write, buffer, lenp, ppos);
}
static int sysctl_poolsize = INPUT_POOL_WORDS * 32;
ctl_table random_table[] = {
{
- .ctl_name = RANDOM_POOLSIZE,
.procname = "poolsize",
.data = &sysctl_poolsize,
.maxlen = sizeof(int),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = proc_dointvec,
},
{
- .ctl_name = RANDOM_ENTROPY_COUNT,
.procname = "entropy_avail",
.maxlen = sizeof(int),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = proc_dointvec,
.data = &input_pool.entropy_count,
},
{
- .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,
+ .proc_handler = proc_dointvec_minmax,
.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,
+ .proc_handler = proc_dointvec_minmax,
.extra1 = &min_write_thresh,
.extra2 = &max_write_thresh,
},
{
- .ctl_name = RANDOM_BOOT_ID,
.procname = "boot_id",
.data = &sysctl_bootid,
.maxlen = 16,
.mode = 0444,
- .proc_handler = &proc_do_uuid,
- .strategy = &uuid_strategy,
+ .proc_handler = proc_do_uuid,
},
{
- .ctl_name = RANDOM_UUID,
.procname = "uuid",
.maxlen = 16,
.mode = 0444,
- .proc_handler = &proc_do_uuid,
- .strategy = &uuid_strategy,
+ .proc_handler = proc_do_uuid,
},
- { .ctl_name = 0 }
+ { }
};
#endif /* CONFIG_SYSCTL */
-/********************************************************************
- *
- * Random funtions for networking
- *
- ********************************************************************/
-
-/*
- * 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.
- *
- * 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.
- */
-
-/* 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
+static u32 random_int_secret[MD5_MESSAGE_BYTES / 4] ____cacheline_aligned;
-#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 * HZ)
-/*
- * Bit layout of the tcp sequence numbers (before adding current time):
- * bit 24-31: increased after every key exchange
- * bit 0-23: hash(source,dest)
- *
- * The implementation is similar to the algorithm described
- * in the Appendix of RFC 1185, except that
- * - it uses a 1 MHz clock instead of a 250 kHz clock
- * - it performs a rekey every 5 minutes, which is equivalent
- * to a (source,dest) tulple dependent forward jump of the
- * clock by 0..2^(HASH_BITS+1)
- *
- * Thus the average ISN wraparound time is 68 minutes instead of
- * 4.55 hours.
- *
- * SMP cleanup and lock avoidance with poor man's RCU.
- * Manfred Spraul <manfred@colorfullife.com>
- *
- */
-#define COUNT_BITS 8
-#define COUNT_MASK ((1 << COUNT_BITS) - 1)
-#define HASH_BITS 24
-#define HASH_MASK ((1 << HASH_BITS) - 1)
-
-static struct keydata {
- __u32 count; /* already shifted to the final position */
- __u32 secret[12];
-} ____cacheline_aligned ip_keydata[2];
-
-static unsigned int ip_cnt;
-
-static void rekey_seq_generator(struct work_struct *work);
-
-static DECLARE_DELAYED_WORK(rekey_work, rekey_seq_generator);
-
-/*
- * Lock avoidance:
- * The ISN generation runs lockless - it's just a hash over random data.
- * State changes happen every 5 minutes when the random key is replaced.
- * Synchronization is performed by having two copies of the hash function
- * state and rekey_seq_generator always updates the inactive copy.
- * The copy is then activated by updating ip_cnt.
- * The implementation breaks down if someone blocks the thread
- * that processes SYN requests for more than 5 minutes. Should never
- * happen, and even if that happens only a not perfectly compliant
- * ISN is generated, nothing fatal.
- */
-static void rekey_seq_generator(struct work_struct *work)
-{
- struct keydata *keyptr = &ip_keydata[1 ^ (ip_cnt & 1)];
-
- get_random_bytes(keyptr->secret, sizeof(keyptr->secret));
- keyptr->count = (ip_cnt & COUNT_MASK) << HASH_BITS;
- smp_wmb();
- ip_cnt++;
- schedule_delayed_work(&rekey_work, REKEY_INTERVAL);
-}
-
-static inline struct keydata *get_keyptr(void)
-{
- struct keydata *keyptr = &ip_keydata[ip_cnt & 1];
-
- smp_rmb();
-
- return keyptr;
-}
-
-static __init int seqgen_init(void)
+static int __init random_int_secret_init(void)
{
- rekey_seq_generator(NULL);
+ get_random_bytes(random_int_secret, sizeof(random_int_secret));
return 0;
}
-late_initcall(seqgen_init);
-
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-__u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr,
- __be16 sport, __be16 dport)
-{
- __u32 seq;
- __u32 hash[12];
- struct keydata *keyptr = get_keyptr();
-
- /* The procedure is the same as for IPv4, but addresses are longer.
- * Thus we must use twothirdsMD4Transform.
- */
-
- memcpy(hash, saddr, 16);
- hash[4] = ((__force u16)sport << 16) + (__force u16)dport;
- memcpy(&hash[5], keyptr->secret, sizeof(__u32) * 7);
-
- seq = twothirdsMD4Transform((const __u32 *)daddr, hash) & HASH_MASK;
- seq += keyptr->count;
-
- seq += ktime_to_ns(ktime_get_real());
-
- return seq;
-}
-EXPORT_SYMBOL(secure_tcpv6_sequence_number);
-#endif
-
-/* The code below is shamelessly stolen from secure_tcp_sequence_number().
- * All blames to Andrey V. Savochkin <saw@msu.ru>.
- */
-__u32 secure_ip_id(__be32 daddr)
-{
- struct keydata *keyptr;
- __u32 hash[4];
-
- keyptr = get_keyptr();
-
- /*
- * 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] = (__force __u32)daddr;
- hash[1] = keyptr->secret[9];
- hash[2] = keyptr->secret[10];
- hash[3] = keyptr->secret[11];
-
- return half_md4_transform(hash, keyptr->secret);
-}
-
-#ifdef CONFIG_INET
-
-__u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
- __be16 sport, __be16 dport)
-{
- __u32 seq;
- __u32 hash[4];
- struct keydata *keyptr = get_keyptr();
-
- /*
- * 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] = (__force u32)saddr;
- hash[1] = (__force u32)daddr;
- hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
- hash[3] = keyptr->secret[11];
-
- seq = half_md4_transform(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.
- * For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but
- * we also need to limit the resolution so that the u32 seq
- * overlaps less than one time per MSL (2 minutes).
- * Choosing a clock of 64 ns period is OK. (period of 274 s)
- */
- seq += ktime_to_ns(ktime_get_real()) >> 6;
-
- return seq;
-}
-
-/* Generate secure starting point for ephemeral IPV4 transport port search */
-u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
-{
- struct keydata *keyptr = get_keyptr();
- u32 hash[4];
-
- /*
- * Pick a unique starting offset for each ephemeral port search
- * (saddr, daddr, dport) and 48bits of random data.
- */
- hash[0] = (__force u32)saddr;
- hash[1] = (__force u32)daddr;
- hash[2] = (__force u32)dport ^ keyptr->secret[10];
- hash[3] = keyptr->secret[11];
-
- return half_md4_transform(hash, keyptr->secret);
-}
-
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
- __be16 dport)
-{
- struct keydata *keyptr = get_keyptr();
- u32 hash[12];
-
- memcpy(hash, saddr, 16);
- hash[4] = (__force u32)dport;
- memcpy(&hash[5], keyptr->secret, sizeof(__u32) * 7);
-
- return twothirdsMD4Transform((const __u32 *)daddr, hash);
-}
-#endif
-
-#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
-/* Similar to secure_tcp_sequence_number but generate a 48 bit value
- * bit's 32-47 increase every key exchange
- * 0-31 hash(source, dest)
- */
-u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
- __be16 sport, __be16 dport)
-{
- u64 seq;
- __u32 hash[4];
- struct keydata *keyptr = get_keyptr();
-
- hash[0] = (__force u32)saddr;
- hash[1] = (__force u32)daddr;
- hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
- hash[3] = keyptr->secret[11];
-
- seq = half_md4_transform(hash, keyptr->secret);
- seq |= ((u64)keyptr->count) << (32 - HASH_BITS);
-
- seq += ktime_to_ns(ktime_get_real());
- seq &= (1ull << 48) - 1;
-
- return seq;
-}
-EXPORT_SYMBOL(secure_dccp_sequence_number);
-#endif
-
-#endif /* CONFIG_INET */
-
+late_initcall(random_int_secret_init);
/*
* Get a random word for internal kernel use only. Similar to urandom but
* value is not cryptographically secure but for several uses the cost of
* depleting entropy is too high
*/
+DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash);
unsigned int get_random_int(void)
{
- /*
- * Use IP's RNG. It suits our purpose perfectly: it re-keys itself
- * every second, from the entropy pool (and thus creates a limited
- * drain on it), and uses halfMD4Transform within the second. We
- * also mix it with jiffies and the PID:
- */
- return secure_ip_id((__force __be32)(current->pid + jiffies));
+ __u32 *hash = get_cpu_var(get_random_int_hash);
+ unsigned int ret;
+
+ hash[0] += current->pid + jiffies + get_cycles();
+ md5_transform(hash, random_int_secret);
+ ret = hash[0];
+ put_cpu_var(get_random_int_hash);
+
+ return ret;
}
/*
projects / linux-flexiantxendom0-natty.git / blobdiff