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Commit 818e607b authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random 

Pull random driver updates from Ted Ts'o:
 "A number of improvements for the /dev/random driver; the most
  important is the use of a ChaCha20-based CRNG for /dev/urandom, which
  is faster, more efficient, and easier to make scalable for
  silly/abusive userspace programs that want to read from /dev/urandom
  in a tight loop on NUMA systems.

  This set of patches also improves entropy gathering on VM's running on
  Microsoft Azure, and will take advantage of a hw random number
  generator (if present) to initialize the /dev/urandom pool"

(It turns out that the random tree hadn't been in linux-next this time
around, because it had been dropped earlier as being too quiet.  Oh
well).

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: strengthen input validation for RNDADDTOENTCNT
  random: add backtracking protection to the CRNG
  random: make /dev/urandom scalable for silly userspace programs
  random: replace non-blocking pool with a Chacha20-based CRNG
  random: properly align get_random_int_hash
  random: add interrupt callback to VMBus IRQ handler
  random: print a warning for the first ten uninitialized random users
  random: initialize the non-blocking pool via add_hwgenerator_randomness()
parents ff9a082f 86a574de
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crypto/chacha20_generic.c
View file @ 818e607b
......@@ -15,72 +15,11 @@
#include <linux/module.h>
#include <crypto/chacha20.h>
static inline u32 rotl32(u32 v, u8 n)
{
return (v << n) | (v >> (sizeof(v) * 8 - n));
}
static inline u32 le32_to_cpuvp(const void *p)
{
return le32_to_cpup(p);
}
static void chacha20_block(u32 *state, void *stream)
{
u32 x[16], *out = stream;
int i;
for (i = 0; i < ARRAY_SIZE(x); i++)
x[i] = state[i];
for (i = 0; i < 20; i += 2) {
x[0] += x[4]; x[12] = rotl32(x[12] ^ x[0], 16);
x[1] += x[5]; x[13] = rotl32(x[13] ^ x[1], 16);
x[2] += x[6]; x[14] = rotl32(x[14] ^ x[2], 16);
x[3] += x[7]; x[15] = rotl32(x[15] ^ x[3], 16);
x[8] += x[12]; x[4] = rotl32(x[4] ^ x[8], 12);
x[9] += x[13]; x[5] = rotl32(x[5] ^ x[9], 12);
x[10] += x[14]; x[6] = rotl32(x[6] ^ x[10], 12);
x[11] += x[15]; x[7] = rotl32(x[7] ^ x[11], 12);
x[0] += x[4]; x[12] = rotl32(x[12] ^ x[0], 8);
x[1] += x[5]; x[13] = rotl32(x[13] ^ x[1], 8);
x[2] += x[6]; x[14] = rotl32(x[14] ^ x[2], 8);
x[3] += x[7]; x[15] = rotl32(x[15] ^ x[3], 8);
x[8] += x[12]; x[4] = rotl32(x[4] ^ x[8], 7);
x[9] += x[13]; x[5] = rotl32(x[5] ^ x[9], 7);
x[10] += x[14]; x[6] = rotl32(x[6] ^ x[10], 7);
x[11] += x[15]; x[7] = rotl32(x[7] ^ x[11], 7);
x[0] += x[5]; x[15] = rotl32(x[15] ^ x[0], 16);
x[1] += x[6]; x[12] = rotl32(x[12] ^ x[1], 16);
x[2] += x[7]; x[13] = rotl32(x[13] ^ x[2], 16);
x[3] += x[4]; x[14] = rotl32(x[14] ^ x[3], 16);
x[10] += x[15]; x[5] = rotl32(x[5] ^ x[10], 12);
x[11] += x[12]; x[6] = rotl32(x[6] ^ x[11], 12);
x[8] += x[13]; x[7] = rotl32(x[7] ^ x[8], 12);
x[9] += x[14]; x[4] = rotl32(x[4] ^ x[9], 12);
x[0] += x[5]; x[15] = rotl32(x[15] ^ x[0], 8);
x[1] += x[6]; x[12] = rotl32(x[12] ^ x[1], 8);
x[2] += x[7]; x[13] = rotl32(x[13] ^ x[2], 8);
x[3] += x[4]; x[14] = rotl32(x[14] ^ x[3], 8);
x[10] += x[15]; x[5] = rotl32(x[5] ^ x[10], 7);
x[11] += x[12]; x[6] = rotl32(x[6] ^ x[11], 7);
x[8] += x[13]; x[7] = rotl32(x[7] ^ x[8], 7);
x[9] += x[14]; x[4] = rotl32(x[4] ^ x[9], 7);
}
for (i = 0; i < ARRAY_SIZE(x); i++)
out[i] = cpu_to_le32(x[i] + state[i]);
state[12]++;
}
static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes)
{
......
drivers/char/random.c
View file @ 818e607b
......@@ -261,6 +261,7 @@
#include <linux/syscalls.h>
#include <linux/completion.h>
#include <linux/uuid.h>
#include <crypto/chacha20.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
......@@ -413,6 +414,34 @@ static struct fasync_struct *fasync;
static DEFINE_SPINLOCK(random_ready_list_lock);
static LIST_HEAD(random_ready_list);
struct crng_state {
__u32 state[16];
unsigned long init_time;
spinlock_t lock;
};
struct crng_state primary_crng = {
.lock = __SPIN_LOCK_UNLOCKED(primary_crng.lock),
};
/*
* crng_init = 0 --> Uninitialized
* 1 --> Initialized
* 2 --> Initialized from input_pool
*
* crng_init is protected by primary_crng->lock, and only increases
* its value (from 0->1->2).
*/
static int crng_init = 0;
#define crng_ready() (likely(crng_init > 0))
static int crng_init_cnt = 0;
#define CRNG_INIT_CNT_THRESH (2*CHACHA20_KEY_SIZE)
static void _extract_crng(struct crng_state *crng,
__u8 out[CHACHA20_BLOCK_SIZE]);
static void _crng_backtrack_protect(struct crng_state *crng,
__u8 tmp[CHACHA20_BLOCK_SIZE], int used);
static void process_random_ready_list(void);
/**********************************************************************
*
* OS independent entropy store. Here are the functions which handle
......@@ -442,10 +471,15 @@ struct entropy_store {
__u8 last_data[EXTRACT_SIZE];
};
static ssize_t extract_entropy(struct entropy_store *r, void *buf,
size_t nbytes, int min, int rsvd);
static ssize_t _extract_entropy(struct entropy_store *r, void *buf,
size_t nbytes, int fips);
static void crng_reseed(struct crng_state *crng, struct entropy_store *r);
static void push_to_pool(struct work_struct *work);
static __u32 input_pool_data[INPUT_POOL_WORDS];
static __u32 blocking_pool_data[OUTPUT_POOL_WORDS];
static __u32 nonblocking_pool_data[OUTPUT_POOL_WORDS];
static struct entropy_store input_pool = {
.poolinfo = &poolinfo_table[0],
......@@ -466,16 +500,6 @@ static struct entropy_store blocking_pool = {
push_to_pool),
};
static struct entropy_store nonblocking_pool = {
.poolinfo = &poolinfo_table[1],
.name = "nonblocking",
.pull = &input_pool,
.lock = __SPIN_LOCK_UNLOCKED(nonblocking_pool.lock),
.pool = nonblocking_pool_data,
.push_work = __WORK_INITIALIZER(nonblocking_pool.push_work,
push_to_pool),
};
static __u32 const twist_table[8] = {
0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
......@@ -678,12 +702,6 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
if (!r->initialized && r->entropy_total > 128) {
r->initialized = 1;
r->entropy_total = 0;
if (r == &nonblocking_pool) {
prandom_reseed_late();
process_random_ready_list();
wake_up_all(&urandom_init_wait);
pr_notice("random: %s pool is initialized\n", r->name);
}
}
trace_credit_entropy_bits(r->name, nbits,
......@@ -693,47 +711,264 @@ static void credit_entropy_bits(struct entropy_store *r, int nbits)
if (r == &input_pool) {
int entropy_bits = entropy_count >> ENTROPY_SHIFT;
if (crng_init < 2 && entropy_bits >= 128) {
crng_reseed(&primary_crng, r);
entropy_bits = r->entropy_count >> ENTROPY_SHIFT;
}
/* should we wake readers? */
if (entropy_bits >= random_read_wakeup_bits) {
wake_up_interruptible(&random_read_wait);
kill_fasync(&fasync, SIGIO, POLL_IN);
}
/* If the input pool is getting full, send some
* entropy to the two output pools, flipping back and
* forth between them, until the output pools are 75%
* full.
* entropy to the blocking pool until it is 75% full.
*/
if (entropy_bits > random_write_wakeup_bits &&
r->initialized &&
r->entropy_total >= 2*random_read_wakeup_bits) {
static struct entropy_store *last = &blocking_pool;
struct entropy_store *other = &blocking_pool;
if (last == &blocking_pool)
other = &nonblocking_pool;
if (other->entropy_count <=
3 * other->poolinfo->poolfracbits / 4)
last = other;
if (last->entropy_count <=
3 * last->poolinfo->poolfracbits / 4) {
schedule_work(&last->push_work);
3 * other->poolinfo->poolfracbits / 4) {
schedule_work(&other->push_work);
r->entropy_total = 0;
}
}
}
}
static void credit_entropy_bits_safe(struct entropy_store *r, int nbits)
static int credit_entropy_bits_safe(struct entropy_store *r, int nbits)
{
const int nbits_max = (int)(~0U >> (ENTROPY_SHIFT + 1));
if (nbits < 0)
return -EINVAL;
/* Cap the value to avoid overflows */
nbits = min(nbits, nbits_max);
nbits = max(nbits, -nbits_max);
credit_entropy_bits(r, nbits);
return 0;
}
/*********************************************************************
*
* CRNG using CHACHA20
*
*********************************************************************/
#define CRNG_RESEED_INTERVAL (300*HZ)
static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
#ifdef CONFIG_NUMA
/*
* Hack to deal with crazy userspace progams when they are all trying
* to access /dev/urandom in parallel. The programs are almost
* certainly doing something terribly wrong, but we'll work around
* their brain damage.
*/
static struct crng_state **crng_node_pool __read_mostly;
#endif
static void crng_initialize(struct crng_state *crng)
{
int i;
unsigned long rv;
memcpy(&crng->state[0], "expand 32-byte k", 16);
if (crng == &primary_crng)
_extract_entropy(&input_pool, &crng->state[4],
sizeof(__u32) * 12, 0);
else
get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
for (i = 4; i < 16; i++) {
if (!arch_get_random_seed_long(&rv) &&
!arch_get_random_long(&rv))
rv = random_get_entropy();
crng->state[i] ^= rv;
}
crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
}
static int crng_fast_load(const char *cp, size_t len)
{
unsigned long flags;
char *p;
if (!spin_trylock_irqsave(&primary_crng.lock, flags))
return 0;
if (crng_ready()) {
spin_unlock_irqrestore(&primary_crng.lock, flags);
return 0;
}
p = (unsigned char *) &primary_crng.state[4];
while (len > 0 && crng_init_cnt < CRNG_INIT_CNT_THRESH) {
p[crng_init_cnt % CHACHA20_KEY_SIZE] ^= *cp;
cp++; crng_init_cnt++; len--;
}
if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) {
crng_init = 1;
wake_up_interruptible(&crng_init_wait);
pr_notice("random: fast init done\n");
}
spin_unlock_irqrestore(&primary_crng.lock, flags);
return 1;
}
static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
{
unsigned long flags;
int i, num;
union {
__u8 block[CHACHA20_BLOCK_SIZE];
__u32 key[8];
} buf;
if (r) {
num = extract_entropy(r, &buf, 32, 16, 0);
if (num == 0)
return;
} else {
_extract_crng(&primary_crng, buf.block);
_crng_backtrack_protect(&primary_crng, buf.block,
CHACHA20_KEY_SIZE);
}
spin_lock_irqsave(&primary_crng.lock, flags);
for (i = 0; i < 8; i++) {
unsigned long rv;
if (!arch_get_random_seed_long(&rv) &&
!arch_get_random_long(&rv))
rv = random_get_entropy();
crng->state[i+4] ^= buf.key[i] ^ rv;
}
memzero_explicit(&buf, sizeof(buf));
crng->init_time = jiffies;
if (crng == &primary_crng && crng_init < 2) {
crng_init = 2;
process_random_ready_list();
wake_up_interruptible(&crng_init_wait);
pr_notice("random: crng init done\n");
}
spin_unlock_irqrestore(&primary_crng.lock, flags);
}
static inline void maybe_reseed_primary_crng(void)
{
if (crng_init > 2 &&
time_after(jiffies, primary_crng.init_time + CRNG_RESEED_INTERVAL))
crng_reseed(&primary_crng, &input_pool);
}
static inline void crng_wait_ready(void)
{
wait_event_interruptible(crng_init_wait, crng_ready());
}
static void _extract_crng(struct crng_state *crng,
__u8 out[CHACHA20_BLOCK_SIZE])
{
unsigned long v, flags;
if (crng_init > 1 &&
time_after(jiffies, crng->init_time + CRNG_RESEED_INTERVAL))
crng_reseed(crng, crng == &primary_crng ? &input_pool : NULL);
spin_lock_irqsave(&crng->lock, flags);
if (arch_get_random_long(&v))
crng->state[14] ^= v;
chacha20_block(&crng->state[0], out);
if (crng->state[12] == 0)
crng->state[13]++;
spin_unlock_irqrestore(&crng->lock, flags);
}
static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE])
{
struct crng_state *crng = NULL;
#ifdef CONFIG_NUMA
if (crng_node_pool)
crng = crng_node_pool[numa_node_id()];
if (crng == NULL)
#endif
crng = &primary_crng;
_extract_crng(crng, out);
}
/*
* Use the leftover bytes from the CRNG block output (if there is
* enough) to mutate the CRNG key to provide backtracking protection.
*/
static void _crng_backtrack_protect(struct crng_state *crng,
__u8 tmp[CHACHA20_BLOCK_SIZE], int used)
{
unsigned long flags;
__u32 *s, *d;
int i;
used = round_up(used, sizeof(__u32));
if (used + CHACHA20_KEY_SIZE > CHACHA20_BLOCK_SIZE) {
extract_crng(tmp);
used = 0;
}
spin_lock_irqsave(&crng->lock, flags);
s = (__u32 *) &tmp[used];
d = &crng->state[4];
for (i=0; i < 8; i++)
*d++ ^= *s++;
spin_unlock_irqrestore(&crng->lock, flags);
}
static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used)
{
struct crng_state *crng = NULL;
#ifdef CONFIG_NUMA
if (crng_node_pool)
crng = crng_node_pool[numa_node_id()];
if (crng == NULL)
#endif
crng = &primary_crng;
_crng_backtrack_protect(crng, tmp, used);
}
static ssize_t extract_crng_user(void __user *buf, size_t nbytes)
{
ssize_t ret = 0, i = CHACHA20_BLOCK_SIZE;
__u8 tmp[CHACHA20_BLOCK_SIZE];
int large_request = (nbytes > 256);
while (nbytes) {
if (large_request && need_resched()) {
if (signal_pending(current)) {
if (ret == 0)
ret = -ERESTARTSYS;
break;
}
schedule();
}
extract_crng(tmp);
i = min_t(int, nbytes, CHACHA20_BLOCK_SIZE);
if (copy_to_user(buf, tmp, i)) {
ret = -EFAULT;
break;
}
nbytes -= i;
buf += i;
ret += i;
}
crng_backtrack_protect(tmp, i);
/* Wipe data just written to memory */
memzero_explicit(tmp, sizeof(tmp));
return ret;
}
/*********************************************************************
*
* Entropy input management
......@@ -750,12 +985,12 @@ struct timer_rand_state {
#define INIT_TIMER_RAND_STATE { INITIAL_JIFFIES, };
/*
* Add device- or boot-specific data to the input and nonblocking
* pools to help initialize them to unique values.
* Add device- or boot-specific data to the input pool to help
* initialize it.
*
* None of this adds any entropy, it is meant to avoid the
* problem of the nonblocking pool having similar initial state
* across largely identical devices.
* None of this adds any entropy; it is meant to avoid the problem of
* the entropy pool having similar initial state across largely
* identical devices.
*/
void add_device_randomness(const void *buf, unsigned int size)
{
......@@ -767,11 +1002,6 @@ void add_device_randomness(const void *buf, unsigned int size)
_mix_pool_bytes(&input_pool, buf, size);
_mix_pool_bytes(&input_pool, &time, sizeof(time));
spin_unlock_irqrestore(&input_pool.lock, flags);
spin_lock_irqsave(&nonblocking_pool.lock, flags);
_mix_pool_bytes(&nonblocking_pool, buf, size);
_mix_pool_bytes(&nonblocking_pool, &time, sizeof(time));
spin_unlock_irqrestore(&nonblocking_pool.lock, flags);
}
EXPORT_SYMBOL(add_device_randomness);
......@@ -802,7 +1032,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
sample.jiffies = jiffies;
sample.cycles = random_get_entropy();
sample.num = num;
r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool;
r = &input_pool;
mix_pool_bytes(r, &sample, sizeof(sample));
/*
......@@ -918,11 +1148,21 @@ void add_interrupt_randomness(int irq, int irq_flags)
fast_mix(fast_pool);
add_interrupt_bench(cycles);
if (!crng_ready()) {
if ((fast_pool->count >= 64) &&
crng_fast_load((char *) fast_pool->pool,
sizeof(fast_pool->pool))) {
fast_pool->count = 0;
fast_pool->last = now;
}
return;
}
if ((fast_pool->count < 64) &&
!time_after(now, fast_pool->last + HZ))
return;
r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool;
r = &input_pool;
if (!spin_trylock(&r->lock))
return;
......@@ -946,6 +1186,7 @@ void add_interrupt_randomness(int irq, int irq_flags)
/* award one bit for the contents of the fast pool */
credit_entropy_bits(r, credit + 1);
}
EXPORT_SYMBOL_GPL(add_interrupt_randomness);
#ifdef CONFIG_BLOCK
void add_disk_randomness(struct gendisk *disk)
......@@ -965,9 +1206,6 @@ EXPORT_SYMBOL_GPL(add_disk_randomness);
*
*********************************************************************/
static ssize_t extract_entropy(struct entropy_store *r, void *buf,
size_t nbytes, int min, int rsvd);
/*
* This utility inline function is responsible for transferring entropy
* from the primary pool to the secondary extraction pool. We make
......@@ -1142,6 +1380,36 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
memzero_explicit(&hash, sizeof(hash));
}
static ssize_t _extract_entropy(struct entropy_store *r, void *buf,
size_t nbytes, int fips)
{
ssize_t ret = 0, i;
__u8 tmp[EXTRACT_SIZE];
unsigned long flags;
while (nbytes) {
extract_buf(r, tmp);
if (fips) {
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;
buf += i;
ret += i;
}
/* Wipe data just returned from memory */
memzero_explicit(tmp, sizeof(tmp));
return ret;
}
/*
* This function extracts randomness from the "entropy pool", and
* returns it in a buffer.
......@@ -1154,7 +1422,6 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
static ssize_t extract_entropy(struct entropy_store *r, void *buf,
size_t nbytes, int min, int reserved)
{
ssize_t ret = 0, i;
__u8 tmp[EXTRACT_SIZE];
unsigned long flags;
......@@ -1178,27 +1445,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
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;
buf += i;
ret += i;
}
/* Wipe data just returned from memory */
memzero_explicit(tmp, sizeof(tmp));
return ret;
return _extract_entropy(r, buf, nbytes, fips_enabled);
}
/*
......@@ -1253,15 +1500,28 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
*/
void get_random_bytes(void *buf, int nbytes)
{
__u8 tmp[CHACHA20_BLOCK_SIZE];
#if DEBUG_RANDOM_BOOT > 0
if (unlikely(nonblocking_pool.initialized == 0))
if (!crng_ready())
printk(KERN_NOTICE "random: %pF get_random_bytes called "
"with %d bits of entropy available\n",
(void *) _RET_IP_,
nonblocking_pool.entropy_total);
"with crng_init = %d\n", (void *) _RET_IP_, crng_init);
#endif
trace_get_random_bytes(nbytes, _RET_IP_);
extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0);
while (nbytes >= CHACHA20_BLOCK_SIZE) {
extract_crng(buf);
buf += CHACHA20_BLOCK_SIZE;
nbytes -= CHACHA20_BLOCK_SIZE;
}
if (nbytes > 0) {
extract_crng(tmp);
memcpy(buf, tmp, nbytes);
crng_backtrack_protect(tmp, nbytes);
} else
crng_backtrack_protect(tmp, CHACHA20_BLOCK_SIZE);
memzero_explicit(tmp, sizeof(tmp));
}
EXPORT_SYMBOL(get_random_bytes);
......@@ -1279,7 +1539,7 @@ int add_random_ready_callback(struct random_ready_callback *rdy)
unsigned long flags;
int err = -EALREADY;
if (likely(nonblocking_pool.initialized))
if (crng_ready())
return err;
owner = rdy->owner;
......@@ -1287,7 +1547,7 @@ int add_random_ready_callback(struct random_ready_callback *rdy)
return -ENOENT;
spin_lock_irqsave(&random_ready_list_lock, flags);
if (nonblocking_pool.initialized)
if (crng_ready())
goto out;
owner = NULL;
......@@ -1351,7 +1611,7 @@ void get_random_bytes_arch(void *buf, int nbytes)
}
if (nbytes)
extract_entropy(&nonblocking_pool, p, nbytes, 0, 0);
get_random_bytes(p, nbytes);
}
EXPORT_SYMBOL(get_random_bytes_arch);
......@@ -1394,9 +1654,31 @@ static void init_std_data(struct entropy_store *r)
*/
static int rand_initialize(void)
{
#ifdef CONFIG_NUMA
int i;
int num_nodes = num_possible_nodes();
struct crng_state *crng;
struct crng_state **pool;
#endif
init_std_data(&input_pool);
init_std_data(&blocking_pool);
init_std_data(&nonblocking_pool);
crng_initialize(&primary_crng);
#ifdef CONFIG_NUMA
pool = kmalloc(num_nodes * sizeof(void *),
GFP_KERNEL|__GFP_NOFAIL|__GFP_ZERO);
for (i=0; i < num_nodes; i++) {
crng = kmalloc_node(sizeof(struct crng_state),
GFP_KERNEL | __GFP_NOFAIL, i);
spin_lock_init(&crng->lock);
crng_initialize(crng);
pool[i] = crng;
}
mb();
crng_node_pool = pool;
#endif
return 0;
}
early_initcall(rand_initialize);
......@@ -1458,18 +1740,22 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
static ssize_t
urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
unsigned long flags;
static int maxwarn = 10;
int ret;
if (unlikely(nonblocking_pool.initialized == 0))
printk_once(KERN_NOTICE "random: %s urandom read "
"with %d bits of entropy available\n",
current->comm, nonblocking_pool.entropy_total);
if (!crng_ready() && maxwarn > 0) {
maxwarn--;
printk(KERN_NOTICE "random: %s: uninitialized urandom read "
"(%zd bytes read)\n",
current->comm, nbytes);
spin_lock_irqsave(&primary_crng.lock, flags);
crng_init_cnt = 0;
spin_unlock_irqrestore(&primary_crng.lock, flags);
}
nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
ret = extract_entropy_user(&nonblocking_pool, buf, nbytes);
trace_urandom_read(8 * nbytes, ENTROPY_BITS(&nonblocking_pool),
ENTROPY_BITS(&input_pool));
ret = extract_crng_user(buf, nbytes);
trace_urandom_read(8 * nbytes, 0, ENTROPY_BITS(&input_pool));
return ret;
}
......@@ -1515,10 +1801,7 @@ static ssize_t random_write(struct file *file, const char __user *buffer,
{
size_t ret;
ret = write_pool(&blocking_pool, buffer, count);
if (ret)
return ret;
ret = write_pool(&nonblocking_pool, buffer, count);
ret = write_pool(&input_pool, buffer, count);
if (ret)
return ret;
......@@ -1543,8 +1826,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
return -EPERM;
if (get_user(ent_count, p))
return -EFAULT;
credit_entropy_bits_safe(&input_pool, ent_count);
return 0;
return credit_entropy_bits_safe(&input_pool, ent_count);
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
......@@ -1558,8 +1840,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
size);
if (retval < 0)
return retval;
credit_entropy_bits_safe(&input_pool, ent_count);
return 0;
return credit_entropy_bits_safe(&input_pool, ent_count);
case RNDZAPENTCNT:
case RNDCLEARPOOL:
/*
......@@ -1569,7 +1850,6 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
input_pool.entropy_count = 0;
nonblocking_pool.entropy_count = 0;
blocking_pool.entropy_count = 0;
return 0;
default:
......@@ -1611,11 +1891,10 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
if (flags & GRND_RANDOM)
return _random_read(flags & GRND_NONBLOCK, buf, count);
if (unlikely(nonblocking_pool.initialized == 0)) {
if (!crng_ready()) {
if (flags & GRND_NONBLOCK)
return -EAGAIN;
wait_event_interruptible(urandom_init_wait,
nonblocking_pool.initialized);
crng_wait_ready();
if (signal_pending(current))
return -ERESTARTSYS;
}
......@@ -1773,13 +2052,15 @@ int random_int_secret_init(void)
return 0;
}
static DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash)
__aligned(sizeof(unsigned long));
/*
* Get a random word for internal kernel use only. Similar to urandom but
* with the goal of minimal entropy pool depletion. As a result, the random
* value is not cryptographically secure but for several uses the cost of
* depleting entropy is too high
*/
static DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash);
unsigned int get_random_int(void)
{
__u32 *hash;
......@@ -1849,6 +2130,11 @@ void add_hwgenerator_randomness(const char *buffer, size_t count,
{
struct entropy_store *poolp = &input_pool;
if (!crng_ready()) {
crng_fast_load(buffer, count);
return;
}
/* Suspend writing if we're above the trickle threshold.
* We'll be woken up again once below random_write_wakeup_thresh,
* or when the calling thread is about to terminate.
......
drivers/hv/vmbus_drv.c
View file @ 818e607b
......@@ -42,6 +42,7 @@
#include <linux/screen_info.h>
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
#include "hyperv_vmbus.h"
static struct acpi_device *hv_acpi_dev;
......@@ -806,6 +807,8 @@ static void vmbus_isr(void)
else
tasklet_schedule(hv_context.msg_dpc[cpu]);
}
add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
}
......
include/crypto/chacha20.h
View file @ 818e607b
......@@ -16,6 +16,7 @@ struct chacha20_ctx {
u32 key[8];
};
void chacha20_block(u32 *state, void *stream);
void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv);
int crypto_chacha20_setkey(struct crypto_tfm *tfm, const u8 *key,
unsigned int keysize);
......
lib/Makefile
View file @ 818e607b
......@@ -19,7 +19,7 @@ KCOV_INSTRUMENT_dynamic_debug.o := n
lib-y := ctype.o string.o vsprintf.o cmdline.o \
rbtree.o radix-tree.o dump_stack.o timerqueue.o\
idr.o int_sqrt.o extable.o \
sha1.o md5.o irq_regs.o argv_split.o \
sha1.o chacha20.o md5.o irq_regs.o argv_split.o \
flex_proportions.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
earlycpio.o seq_buf.o nmi_backtrace.o nodemask.o
......
lib/chacha20.c 0 → 100644
View file @ 818e607b
/*
* ChaCha20 256-bit cipher algorithm, RFC7539
*
* Copyright (C) 2015 Martin Willi
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/bitops.h>
#include <linux/cryptohash.h>
#include <asm/unaligned.h>
#include <crypto/chacha20.h>
static inline u32 rotl32(u32 v, u8 n)
{
return (v << n) | (v >> (sizeof(v) * 8 - n));
}
extern void chacha20_block(u32 *state, void *stream)
{
u32 x[16], *out = stream;
int i;
for (i = 0; i < ARRAY_SIZE(x); i++)
x[i] = state[i];
for (i = 0; i < 20; i += 2) {
x[0] += x[4]; x[12] = rotl32(x[12] ^ x[0], 16);
x[1] += x[5]; x[13] = rotl32(x[13] ^ x[1], 16);
x[2] += x[6]; x[14] = rotl32(x[14] ^ x[2], 16);
x[3] += x[7]; x[15] = rotl32(x[15] ^ x[3], 16);
x[8] += x[12]; x[4] = rotl32(x[4] ^ x[8], 12);
x[9] += x[13]; x[5] = rotl32(x[5] ^ x[9], 12);
x[10] += x[14]; x[6] = rotl32(x[6] ^ x[10], 12);
x[11] += x[15]; x[7] = rotl32(x[7] ^ x[11], 12);
x[0] += x[4]; x[12] = rotl32(x[12] ^ x[0], 8);
x[1] += x[5]; x[13] = rotl32(x[13] ^ x[1], 8);
x[2] += x[6]; x[14] = rotl32(x[14] ^ x[2], 8);
x[3] += x[7]; x[15] = rotl32(x[15] ^ x[3], 8);
x[8] += x[12]; x[4] = rotl32(x[4] ^ x[8], 7);
x[9] += x[13]; x[5] = rotl32(x[5] ^ x[9], 7);
x[10] += x[14]; x[6] = rotl32(x[6] ^ x[10], 7);
x[11] += x[15]; x[7] = rotl32(x[7] ^ x[11], 7);
x[0] += x[5]; x[15] = rotl32(x[15] ^ x[0], 16);
x[1] += x[6]; x[12] = rotl32(x[12] ^ x[1], 16);
x[2] += x[7]; x[13] = rotl32(x[13] ^ x[2], 16);
x[3] += x[4]; x[14] = rotl32(x[14] ^ x[3], 16);
x[10] += x[15]; x[5] = rotl32(x[5] ^ x[10], 12);
x[11] += x[12]; x[6] = rotl32(x[6] ^ x[11], 12);
x[8] += x[13]; x[7] = rotl32(x[7] ^ x[8], 12);
x[9] += x[14]; x[4] = rotl32(x[4] ^ x[9], 12);
x[0] += x[5]; x[15] = rotl32(x[15] ^ x[0], 8);
x[1] += x[6]; x[12] = rotl32(x[12] ^ x[1], 8);
x[2] += x[7]; x[13] = rotl32(x[13] ^ x[2], 8);
x[3] += x[4]; x[14] = rotl32(x[14] ^ x[3], 8);
x[10] += x[15]; x[5] = rotl32(x[5] ^ x[10], 7);
x[11] += x[12]; x[6] = rotl32(x[6] ^ x[11], 7);
x[8] += x[13]; x[7] = rotl32(x[7] ^ x[8], 7);
x[9] += x[14]; x[4] = rotl32(x[4] ^ x[9], 7);
}
for (i = 0; i < ARRAY_SIZE(x); i++)
out[i] = cpu_to_le32(x[i] + state[i]);
state[12]++;
}
EXPORT_SYMBOL(chacha20_block);
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