linux/lib/random32.c

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/*
This is a maximally equidistributed combined Tausworthe generator
based on code from GNU Scientific Library 1.5 (30 Jun 2004)
x_n = (s1_n ^ s2_n ^ s3_n)
s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
The period of this generator is about 2^88.
From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
This is available on the net from L'Ecuyer's home page,
http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps
There is an erratum in the paper "Tables of Maximally
Equidistributed Combined LFSR Generators", Mathematics of
Computation, 68, 225 (1999), 261--269:
http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
... the k_j most significant bits of z_j must be non-
zero, for each j. (Note: this restriction also applies to the
computer code given in [4], but was mistakenly not mentioned in
that paper.)
This affects the seeding procedure by imposing the requirement
s1 > 1, s2 > 7, s3 > 15.
*/
#include <linux/types.h>
#include <linux/percpu.h>
#include <linux/export.h>
#include <linux/jiffies.h>
#include <linux/random.h>
static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
/**
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
* prandom_u32_state - seeded pseudo-random number generator.
* @state: pointer to state structure holding seeded state.
*
* This is used for pseudo-randomness with no outside seeding.
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
* For more random results, use prandom_u32().
*/
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
u32 prandom_u32_state(struct rnd_state *state)
{
#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
return (state->s1 ^ state->s2 ^ state->s3);
}
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
EXPORT_SYMBOL(prandom_u32_state);
/**
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
* prandom_u32 - pseudo random number generator
*
* A 32 bit pseudo-random number is generated using a fast
* algorithm suitable for simulation. This algorithm is NOT
* considered safe for cryptographic use.
*/
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
u32 prandom_u32(void)
{
unsigned long r;
struct rnd_state *state = &get_cpu_var(net_rand_state);
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
r = prandom_u32_state(state);
put_cpu_var(state);
return r;
}
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
EXPORT_SYMBOL(prandom_u32);
/*
* prandom_bytes_state - get the requested number of pseudo-random bytes
*
* @state: pointer to state structure holding seeded state.
* @buf: where to copy the pseudo-random bytes to
* @bytes: the requested number of bytes
*
* This is used for pseudo-randomness with no outside seeding.
* For more random results, use prandom_bytes().
*/
void prandom_bytes_state(struct rnd_state *state, void *buf, int bytes)
{
unsigned char *p = buf;
int i;
for (i = 0; i < round_down(bytes, sizeof(u32)); i += sizeof(u32)) {
u32 random = prandom_u32_state(state);
int j;
for (j = 0; j < sizeof(u32); j++) {
p[i + j] = random;
random >>= BITS_PER_BYTE;
}
}
if (i < bytes) {
u32 random = prandom_u32_state(state);
for (; i < bytes; i++) {
p[i] = random;
random >>= BITS_PER_BYTE;
}
}
}
EXPORT_SYMBOL(prandom_bytes_state);
/**
* prandom_bytes - get the requested number of pseudo-random bytes
* @buf: where to copy the pseudo-random bytes to
* @bytes: the requested number of bytes
*/
void prandom_bytes(void *buf, int bytes)
{
struct rnd_state *state = &get_cpu_var(net_rand_state);
prandom_bytes_state(state, buf, bytes);
put_cpu_var(state);
}
EXPORT_SYMBOL(prandom_bytes);
/**
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
* prandom_seed - add entropy to pseudo random number generator
* @seed: seed value
*
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
* Add some additional seeding to the prandom pool.
*/
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
void prandom_seed(u32 entropy)
{
int i;
/*
* No locking on the CPUs, but then somewhat random results are, well,
* expected.
*/
for_each_possible_cpu (i) {
struct rnd_state *state = &per_cpu(net_rand_state, i);
state->s1 = __seed(state->s1 ^ entropy, 1);
}
}
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
EXPORT_SYMBOL(prandom_seed);
/*
* Generate some initially weak seeding values to allow
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
* to start the prandom_u32() engine.
*/
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
static int __init prandom_init(void)
{
int i;
for_each_possible_cpu(i) {
struct rnd_state *state = &per_cpu(net_rand_state,i);
#define LCG(x) ((x) * 69069) /* super-duper LCG */
state->s1 = __seed(LCG(i + jiffies), 1);
state->s2 = __seed(LCG(state->s1), 7);
state->s3 = __seed(LCG(state->s2), 15);
/* "warm it up" */
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
prandom_u32_state(state);
prandom_u32_state(state);
prandom_u32_state(state);
prandom_u32_state(state);
prandom_u32_state(state);
prandom_u32_state(state);
}
return 0;
}
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
core_initcall(prandom_init);
/*
* Generate better values after random number generator
* is fully initialized.
*/
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
static int __init prandom_reseed(void)
{
int i;
for_each_possible_cpu(i) {
struct rnd_state *state = &per_cpu(net_rand_state,i);
u32 seeds[3];
get_random_bytes(&seeds, sizeof(seeds));
state->s1 = __seed(seeds[0], 1);
state->s2 = __seed(seeds[1], 7);
state->s3 = __seed(seeds[2], 15);
/* mix it in */
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
prandom_u32_state(state);
}
return 0;
}
random32: rename random32 to prandom This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 00:04:23 +00:00
late_initcall(prandom_reseed);