diff options
Diffstat (limited to 'target/linux/generic-2.4/files/crypto/ocf/random.c')
| -rw-r--r-- | target/linux/generic-2.4/files/crypto/ocf/random.c | 322 | 
1 files changed, 322 insertions, 0 deletions
diff --git a/target/linux/generic-2.4/files/crypto/ocf/random.c b/target/linux/generic-2.4/files/crypto/ocf/random.c new file mode 100644 index 000000000..38dad13d7 --- /dev/null +++ b/target/linux/generic-2.4/files/crypto/ocf/random.c @@ -0,0 +1,322 @@ +/* + * A system independant way of adding entropy to the kernels pool + * this way the drivers can focus on the real work and we can take + * care of pushing it to the appropriate place in the kernel. + * + * This should be fast and callable from timers/interrupts + * + * Written by David McCullough <david_mccullough@mcafee.com> + * Copyright (C) 2006-2010 David McCullough + * Copyright (C) 2004-2005 Intel Corporation. + * + * LICENSE TERMS + * + * The free distribution and use of this software in both source and binary + * form is allowed (with or without changes) provided that: + * + *   1. distributions of this source code include the above copyright + *      notice, this list of conditions and the following disclaimer; + * + *   2. distributions in binary form include the above copyright + *      notice, this list of conditions and the following disclaimer + *      in the documentation and/or other associated materials; + * + *   3. the copyright holder's name is not used to endorse products + *      built using this software without specific written permission. + * + * ALTERNATIVELY, provided that this notice is retained in full, this product + * may be distributed under the terms of the GNU General Public License (GPL), + * in which case the provisions of the GPL apply INSTEAD OF those given above. + * + * DISCLAIMER + * + * This software is provided 'as is' with no explicit or implied warranties + * in respect of its properties, including, but not limited to, correctness + * and/or fitness for purpose. + */ + +#ifndef AUTOCONF_INCLUDED +#include <linux/config.h> +#endif +#include <linux/module.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/version.h> +#include <linux/unistd.h> +#include <linux/poll.h> +#include <linux/random.h> +#include <cryptodev.h> + +#ifdef CONFIG_OCF_FIPS +#include "rndtest.h" +#endif + +#ifndef HAS_RANDOM_INPUT_WAIT +#error "Please do not enable OCF_RANDOMHARVEST unless you have applied patches" +#endif + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27) +#include <linux/sched.h> +#define	kill_proc(p,s,v)	send_sig(s,find_task_by_vpid(p),0) +#endif + +/* + * a hack to access the debug levels from the crypto driver + */ +extern int crypto_debug; +#define debug crypto_debug + +/* + * a list of all registered random providers + */ +static LIST_HEAD(random_ops); +static int started = 0; +static int initted = 0; + +struct random_op { +	struct list_head random_list; +	u_int32_t driverid; +	int (*read_random)(void *arg, u_int32_t *buf, int len); +	void *arg; +}; + +static int random_proc(void *arg); + +static pid_t		randomproc = (pid_t) -1; +static spinlock_t	random_lock; + +/* + * just init the spin locks + */ +static int +crypto_random_init(void) +{ +	spin_lock_init(&random_lock); +	initted = 1; +	return(0); +} + +/* + * Add the given random reader to our list (if not present) + * and start the thread (if not already started) + * + * we have to assume that driver id is ok for now + */ +int +crypto_rregister( +	u_int32_t driverid, +	int (*read_random)(void *arg, u_int32_t *buf, int len), +	void *arg) +{ +	unsigned long flags; +	int ret = 0; +	struct random_op	*rops, *tmp; + +	dprintk("%s,%d: %s(0x%x, %p, %p)\n", __FILE__, __LINE__, +			__FUNCTION__, driverid, read_random, arg); + +	if (!initted) +		crypto_random_init(); + +#if 0 +	struct cryptocap	*cap; + +	cap = crypto_checkdriver(driverid); +	if (!cap) +		return EINVAL; +#endif + +	list_for_each_entry_safe(rops, tmp, &random_ops, random_list) { +		if (rops->driverid == driverid && rops->read_random == read_random) +			return EEXIST; +	} + +	rops = (struct random_op *) kmalloc(sizeof(*rops), GFP_KERNEL); +	if (!rops) +		return ENOMEM; + +	rops->driverid    = driverid; +	rops->read_random = read_random; +	rops->arg = arg; + +	spin_lock_irqsave(&random_lock, flags); +	list_add_tail(&rops->random_list, &random_ops); +	if (!started) { +		randomproc = kernel_thread(random_proc, NULL, CLONE_FS|CLONE_FILES); +		if (randomproc < 0) { +			ret = randomproc; +			printk("crypto: crypto_rregister cannot start random thread; " +					"error %d", ret); +		} else +			started = 1; +	} +	spin_unlock_irqrestore(&random_lock, flags); + +	return ret; +} +EXPORT_SYMBOL(crypto_rregister); + +int +crypto_runregister_all(u_int32_t driverid) +{ +	struct random_op *rops, *tmp; +	unsigned long flags; + +	dprintk("%s,%d: %s(0x%x)\n", __FILE__, __LINE__, __FUNCTION__, driverid); + +	list_for_each_entry_safe(rops, tmp, &random_ops, random_list) { +		if (rops->driverid == driverid) { +			list_del(&rops->random_list); +			kfree(rops); +		} +	} + +	spin_lock_irqsave(&random_lock, flags); +	if (list_empty(&random_ops) && started) +		kill_proc(randomproc, SIGKILL, 1); +	spin_unlock_irqrestore(&random_lock, flags); +	return(0); +} +EXPORT_SYMBOL(crypto_runregister_all); + +/* + * while we can add entropy to random.c continue to read random data from + * the drivers and push it to random. + */ +static int +random_proc(void *arg) +{ +	int n; +	int wantcnt; +	int bufcnt = 0; +	int retval = 0; +	int *buf = NULL; + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) +	daemonize(); +	spin_lock_irq(¤t->sigmask_lock); +	sigemptyset(¤t->blocked); +	recalc_sigpending(current); +	spin_unlock_irq(¤t->sigmask_lock); +	sprintf(current->comm, "ocf-random"); +#else +	daemonize("ocf-random"); +	allow_signal(SIGKILL); +#endif + +	(void) get_fs(); +	set_fs(get_ds()); + +#ifdef CONFIG_OCF_FIPS +#define NUM_INT (RNDTEST_NBYTES/sizeof(int)) +#else +#define NUM_INT 32 +#endif + +	/* +	 * some devices can transferr their RNG data direct into memory, +	 * so make sure it is device friendly +	 */ +	buf = kmalloc(NUM_INT * sizeof(int), GFP_DMA); +	if (NULL == buf) { +		printk("crypto: RNG could not allocate memory\n"); +		retval = -ENOMEM; +		goto bad_alloc; +	} + +	wantcnt = NUM_INT;   /* start by adding some entropy */ + +	/* +	 * its possible due to errors or driver removal that we no longer +	 * have anything to do,  if so exit or we will consume all the CPU +	 * doing nothing +	 */ +	while (!list_empty(&random_ops)) { +		struct random_op	*rops, *tmp; + +#ifdef CONFIG_OCF_FIPS +		if (wantcnt) +			wantcnt = NUM_INT; /* FIPs mode can do 20000 bits or none */ +#endif + +		/* see if we can get enough entropy to make the world +		 * a better place. +		 */ +		while (bufcnt < wantcnt && bufcnt < NUM_INT) { +			list_for_each_entry_safe(rops, tmp, &random_ops, random_list) { + +				n = (*rops->read_random)(rops->arg, &buf[bufcnt], +							 NUM_INT - bufcnt); + +				/* on failure remove the random number generator */ +				if (n == -1) { +					list_del(&rops->random_list); +					printk("crypto: RNG (driverid=0x%x) failed, disabling\n", +							rops->driverid); +					kfree(rops); +				} else if (n > 0) +					bufcnt += n; +			} +			/* give up CPU for a bit, just in case as this is a loop */ +			schedule(); +		} + + +#ifdef CONFIG_OCF_FIPS +		if (bufcnt > 0 && rndtest_buf((unsigned char *) &buf[0])) { +			dprintk("crypto: buffer had fips errors, discarding\n"); +			bufcnt = 0; +		} +#endif + +		/* +		 * if we have a certified buffer,  we can send some data +		 * to /dev/random and move along +		 */ +		if (bufcnt > 0) { +			/* add what we have */ +			random_input_words(buf, bufcnt, bufcnt*sizeof(int)*8); +			bufcnt = 0; +		} + +		/* give up CPU for a bit so we don't hog while filling */ +		schedule(); + +		/* wait for needing more */ +		wantcnt = random_input_wait(); + +		if (wantcnt <= 0) +			wantcnt = 0; /* try to get some info again */ +		else +		 	/* round up to one word or we can loop forever */ +			wantcnt = (wantcnt + (sizeof(int)*8)) / (sizeof(int)*8); +		if (wantcnt > NUM_INT) { +			wantcnt = NUM_INT; +		} + +		if (signal_pending(current)) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) +			spin_lock_irq(¤t->sigmask_lock); +#endif +			flush_signals(current); +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) +			spin_unlock_irq(¤t->sigmask_lock); +#endif +		} +	} +	 +	kfree(buf); + +bad_alloc: +	spin_lock_irq(&random_lock); +	randomproc = (pid_t) -1; +	started = 0; +	spin_unlock_irq(&random_lock); + +	return retval; +} +  | 
