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rand: Refactoring finished

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now there are only 4 static functions left:
static mp_digit read_int_dev_random();
static mp_digit read_int_dev_urandom();
static mp_digit make_small_int(mp_digit random_int, int* sign);
static mp_digit make_big_int(mp_digit random_int, int* sign);
Every function is used twice.
the next goal to copy free code is to make a single function
with function pointer out of these 4:
pb_poly *ntru_get_urnd_poly_small(ntru_context *ctx);
pb_poly *ntru_get_rnd_poly_small(ntru_context *ctx);
pb_poly *ntru_get_urnd_poly_big(ntru_context *ctx);
pb_poly *ntru_get_rnd_poly_big(ntru_context *ctx);
But this need to be checkt by a other group member
This commit is contained in:
Malte 2014-04-20 20:27:16 +02:00 committed by malte
parent 21022c9ff8
commit 0bdddc12e7
1 changed files with 81 additions and 151 deletions
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232
src/rand.c
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@ -37,11 +37,9 @@
/*
* static declarations
*/
static mp_digit get_urnd_int_small(int *sign);
static mp_digit get_rnd_int_small(int *sign);
static mp_digit get_urnd_int_big(int *sign);
static mp_digit get_rnd_int_big(int *sign);
static mp_digit read_int_dev_random();
static mp_digit read_int_dev_urandom();
static mp_digit make_small_int(mp_digit random_int, int* sign);
static mp_digit make_big_int(mp_digit random_int, int* sign);
@ -70,9 +68,28 @@ static mp_digit read_int_dev_random()
return random_int;
}
/**
* Reads a single mp_digit out of /dev/urandom and returns this mp_digit
*
* @return the randomly chosen integer
*/
static mp_digit read_int_dev_urandom()
{
int random_data;
mp_digit random_int;
ssize_t result;
random_data = open("/dev/urandom", O_RDONLY);
if ((result = read(random_data, &random_int, sizeof(random_int))) < 0)
NTRU_ABORT("Unable to read /dev/urandom.\n");
close(random_data);
return random_int;
}
/**
* Makes a small integer from the set {-1, 0, 1}
* out of a randomly chosen integer.
* A zero is signed positiv.
*
* @param random_int a randomly chosen mp_digit
* @param sign a integer to store the sign (1==positiv)
@ -90,127 +107,16 @@ static mp_digit make_small_int(mp_digit random_int, int* sign)
} else {
*sign = 0;
}
return random_int;
}
/**
* Gets a random small integer
* from the set {-1, 0, 1} using /dev/random.
* A zero is signed positiv.
* *sig == 1 means positiv integer.
*
* @param sign stores the signness [out]
* @return random small integer
*/
static mp_digit get_rnd_int_small(int *sign)
{
mp_digit random_int = read_int_dev_random();
random_int = make_small_int(random_int, sign);
return random_int;
}
/**
* Gets a random polynomial with coefficients
* from the set {-1 ,0 ,1} using /dev/random.
*
* @param ctx the NTRU context
* @return newly allocated polynomial, must be freed with delete_polynom()
*/
pb_poly *ntru_get_rnd_poly_small(ntru_context *ctx)
{
mp_int chara;
init_integer(&chara);
pb_poly *poly = malloc(sizeof(pb_poly));
init_polynom_size(poly, &chara, ctx->N);
mp_clear(&chara);
for (unsigned int i = 0; i < ctx->N; i++) {
int sign;
int c = get_rnd_int_small(&sign);
mp_set(&(poly->terms[i]), (mp_digit) c);
if (sign == 1)
poly->terms[i].sign = 1;
}
poly->used = ctx->N;
pb_clamp(poly);
return poly;
}
/**
* Reads a single mp_digit out of /dev/urandom and returns this mp_digit
*
* @return the randomly chosen integer
*/
static mp_digit read_int_dev_urandom()
{
int random_data;
mp_digit random_int;
ssize_t result;
random_data = open("/dev/urandom", O_RDONLY);
if ((result = read(random_data, &random_int, sizeof(random_int))) < 0)
NTRU_ABORT("Unable to read /dev/urandom.\n");
close(random_data);
return random_int;
}
/**
* Gets a random small integer
* from the set {-1, 0, 1} using /dev/urandom.
* A zero is signed positiv.
* *sig == 1 means positiv integer.
*
* @param sign stores the signness [out]
* @return random small integer
*/
static mp_digit get_urnd_int_small(int *sign)
{
mp_digit random_int = read_int_dev_urandom();
random_int = make_small_int(random_int, sign);
return random_int;
}
/**
* Gets a random polynomial with coefficients
* from the set {-1 ,0 ,1} using /dev/urandom.
*
* @param ctx the NTRU context
* @return newly allocated polynomial, must be freed with delete_polynom()
*/
pb_poly *ntru_get_urnd_poly_small(ntru_context *ctx)
{
mp_int chara;
init_integer(&chara);
pb_poly *poly = malloc(sizeof(pb_poly));
init_polynom_size(poly, &chara, ctx->N);
mp_clear(&chara);
for (unsigned int i = 0; i < ctx->N; i++) {
int sign;
int c = get_urnd_int_small(&sign);
mp_set(&(poly->terms[i]), (mp_digit) c);
if (sign == 1)
poly->terms[i].sign = 1;
}
poly->used = ctx->N;
pb_clamp(poly);
return poly;
}
/**
* Makes a big integer from the borders of BIG_RAND_MAX
* and BIG_RAND_MIN out of a randomly chosen integer.
*
* @param random_int a randomly chosen mp_digit
* @param sign a integer to store the sign (1==positiv)
* @return random small integer from the set {-1, 0, 1}
* @return random big integer from the borders of BIG_RAND_MAX and BIG_RAND_MIN
*/
static mp_digit make_big_int(mp_digit random_int, int* sign)
{
@ -232,20 +138,62 @@ static mp_digit make_big_int(mp_digit random_int, int* sign)
}
/**
* Gets a random big integer
* from the borders of BIG_RAND_MAX and
* BIG_RAND_MIN using /dev/random.
* A zero is signed positiv.
* *sig == 1 means positiv integer.
* Gets a random polynomial with coefficients
* from the set {-1 ,0 ,1} using /dev/random.
*
* @param sign stores the signness [out]
* @return random small integer
* @param ctx the NTRU context
* @return newly allocated polynomial, must be freed with delete_polynom()
*/
static mp_digit get_rnd_int_big(int *sign)
pb_poly *ntru_get_rnd_poly_small(ntru_context *ctx)
{
mp_digit random_int = read_int_dev_random();
random_int = make_big_int(random_int, sign);
return random_int;
mp_int chara;
init_integer(&chara);
pb_poly *poly = malloc(sizeof(pb_poly));
init_polynom_size(poly, &chara, ctx->N);
mp_clear(&chara);
for (unsigned int i = 0; i < ctx->N; i++) {
int sign;
mp_digit c = read_int_dev_random();
c = make_small_int(c, &sign);
mp_set(&(poly->terms[i]), c);
if (sign == 1)
poly->terms[i].sign = 1;
}
poly->used = ctx->N;
pb_clamp(poly);
return poly;
}
/**
* Gets a random polynomial with coefficients
* from the set {-1 ,0 ,1} using /dev/urandom.
*
* @param ctx the NTRU context
* @return newly allocated polynomial, must be freed with delete_polynom()
*/
pb_poly *ntru_get_urnd_poly_small(ntru_context *ctx)
{
mp_int chara;
init_integer(&chara);
pb_poly *poly = malloc(sizeof(pb_poly));
init_polynom_size(poly, &chara, ctx->N);
mp_clear(&chara);
for (unsigned int i = 0; i < ctx->N; i++) {
int sign;
mp_digit c = read_int_dev_urandom();
c = make_small_int(c, &sign);
mp_set(&(poly->terms[i]), c);
if (sign == 1)
poly->terms[i].sign = 1;
}
poly->used = ctx->N;
pb_clamp(poly);
return poly;
}
/**
@ -266,9 +214,9 @@ pb_poly *ntru_get_rnd_poly_big(ntru_context *ctx)
for (unsigned int i = 0; i < ctx->N; i++) {
int sign;
int c = get_rnd_int_big(&sign);
mp_set(&(poly->terms[i]), (mp_digit) c);
mp_digit c = read_int_dev_random();
c = make_big_int(c, &sign);
mp_set(&(poly->terms[i]), c);
if (sign == 1)
poly->terms[i].sign = 1;
@ -279,24 +227,6 @@ pb_poly *ntru_get_rnd_poly_big(ntru_context *ctx)
return poly;
}
/**
* Gets a random big integer
* from the borders of BIG_RAND_MAX and
* BIG_RAND_MIN using /dev/urandom.
* A zero is signed positiv.
* *sig == 1 means positiv integer.
*
* @param sign stores the signness [out]
* @return random small integer
*/
static mp_digit get_urnd_int_big(int *sign)
{
mp_digit random_int = read_int_dev_urandom();
random_int = random_int % abs(BIG_RAND_MAX - BIG_RAND_MIN);
random_int = make_big_int(random_int, sign);
return random_int;
}
/**
* Gets a random polynomial with coefficients
* from the borders of BIG_RAND_MAX and
@ -315,9 +245,9 @@ pb_poly *ntru_get_urnd_poly_big(ntru_context *ctx)
for (unsigned int i = 0; i < ctx->N; i++) {
int sign;
int c = get_urnd_int_big(&sign);
mp_set(&(poly->terms[i]), (mp_digit) c);
mp_digit c = read_int_dev_urandom();
c = make_big_int(c, &sign);
mp_set(&(poly->terms[i]), c);
if (sign == 1)
poly->terms[i].sign = 1;