random: replace non-blocking pool with a Chacha20-based CRNG (e192be9d) · Commits · 方亚芬 / raspberrypi_linux

crypto/chacha20_generic.c

+0 −61

Original line number	Diff line number	Diff line
		@@ -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

+276 −102

Original line number	Diff line number	Diff line
		@@ -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 +414,31 @@ 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(__u8 out[CHACHA20_BLOCK_SIZE]);
		static void process_random_ready_list(void);

		/**********************************************************************
		*
		* OS independent entropy store. Here are the functions which handle
		@@ -442,10 +468,15 @@ 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 +497,6 @@ 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 +699,6 @@ retry:
		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,
		@@ -693,30 +708,27 @@ retry:
		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;
		}
		}
		@@ -734,6 +746,152 @@ static void credit_entropy_bits_safe(struct entropy_store *r, int nbits)
		credit_entropy_bits(r, nbits);
		}

		/*********************************************************************
		*
		* CRNG using CHACHA20
		*
		*********************************************************************/

		#define CRNG_RESEED_INTERVAL (300*HZ)

		static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);

		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(buf.block);
		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 crng_wait_ready(void)
		{
		wait_event_interruptible(crng_init_wait, crng_ready());
		}

		static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE])
		{
		unsigned long v, flags;
		struct crng_state *crng = &primary_crng;

		if (crng_init > 1 &&
		time_after(jiffies, crng->init_time + CRNG_RESEED_INTERVAL))
		crng_reseed(crng, &input_pool);
		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 ssize_t extract_crng_user(void __user *buf, size_t nbytes)
		{
		ssize_t ret = 0, i;
		__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;
		}

		/* Wipe data just written to memory */
		memzero_explicit(tmp, sizeof(tmp));

		return ret;
		}


		/*********************************************************************
		*
		* Entropy input management
		@@ -750,12 +908,12 @@ 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 +925,6 @@ 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 +955,7 @@ 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 +1071,21 @@ 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;

		@@ -966,9 +1129,6 @@ 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
		@@ -1143,6 +1303,36 @@ 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.
		@@ -1155,7 +1345,6 @@ 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;

		@@ -1179,27 +1368,7 @@ 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);
		}

		/*
		@@ -1254,15 +1423,26 @@ 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);
		memzero_explicit(tmp, nbytes);
		}
		}
		EXPORT_SYMBOL(get_random_bytes);

		@@ -1280,7 +1460,7 @@ 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;
		@@ -1288,7 +1468,7 @@ 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;
		@@ -1352,7 +1532,7 @@ 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);

		@@ -1397,7 +1577,7 @@ static int rand_initialize(void)
		{
		init_std_data(&input_pool);
		init_std_data(&blocking_pool);
		init_std_data(&nonblocking_pool);
		crng_initialize(&primary_crng);
		return 0;
		}
		early_initcall(rand_initialize);
		@@ -1459,22 +1639,22 @@ 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) &&
		maxwarn > 0) {
		if (!crng_ready() && maxwarn > 0) {
		maxwarn--;
		printk(KERN_NOTICE "random: %s: uninitialized urandom read "
		"(%zd bytes read, %d bits of entropy available)\n",
		current->comm, nbytes, nonblocking_pool.entropy_total);
		"(%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;
		}

		@@ -1520,10 +1700,7 @@ 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;

		@@ -1574,7 +1751,6 @@ 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:
		@@ -1616,11 +1792,10 @@ 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;
		}
		@@ -1856,18 +2031,17 @@ void add_hwgenerator_randomness(const char *buffer, size_t count,
		{
		struct entropy_store *poolp = &input_pool;

		if (unlikely(nonblocking_pool.initialized == 0))
		poolp = &nonblocking_pool;
		else {
		/* 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.
		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.
		*/
		wait_event_interruptible(random_write_wait,
		kthread_should_stop() \|\|
		wait_event_interruptible(random_write_wait, kthread_should_stop() \|\|
		ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits);
		}
		mix_pool_bytes(poolp, buffer, count);
		credit_entropy_bits(poolp, entropy);
		}

include/crypto/chacha20.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

+1 −1

Original line number	Diff line number	Diff line
		@@ -22,7 +22,7 @@ KCOV_INSTRUMENT_hweight.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

+79 −0

Original line number	Diff line number	Diff line
		/*
		* 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);