random: Blocking API for accessing nonblocking_pool

The added API calls provide a synchronous function call
get_blocking_random_bytes where the caller is blocked until
the nonblocking_pool is initialized.

CC: Andreas Steffen <andreas.steffen@strongswan.org>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Sandy Harris <sandyinchina@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Stephan Mueller 2015-05-25 15:08:47 +02:00 committed by Herbert Xu
parent 1d9de44e26
commit 16b369a91d
2 changed files with 13 additions and 0 deletions

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@ -1244,6 +1244,18 @@ void get_random_bytes(void *buf, int nbytes)
}
EXPORT_SYMBOL(get_random_bytes);
/*
* Equivalent function to get_random_bytes with the difference that this
* function blocks the request until the nonblocking_pool is initialized.
*/
void get_blocking_random_bytes(void *buf, int nbytes)
{
if (unlikely(nonblocking_pool.initialized == 0))
wait_event(urandom_init_wait, nonblocking_pool.initialized);
extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0);
}
EXPORT_SYMBOL(get_blocking_random_bytes);
/*
* This function will use the architecture-specific hardware random
* number generator if it is available. The arch-specific hw RNG will

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@ -14,6 +14,7 @@ extern void add_input_randomness(unsigned int type, unsigned int code,
extern void add_interrupt_randomness(int irq, int irq_flags);
extern void get_random_bytes(void *buf, int nbytes);
extern void get_blocking_random_bytes(void *buf, int nbytes);
extern void get_random_bytes_arch(void *buf, int nbytes);
void generate_random_uuid(unsigned char uuid_out[16]);
extern int random_int_secret_init(void);