From 734dbdfa5510229b3acee29449c2938efccb6bd6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@lysator.liu.se>
Date: Wed, 26 May 2010 16:20:17 +0200
Subject: [PATCH] * bignum-random-prime.c (_nettle_generate_pocklington_prime):
Also return the used r. Updated caller.
Rev: nettle/bignum-random-prime.c:1.5
Rev: nettle/bignum.h:1.6
---
bignum-random-prime.c | 29 ++++++++++++++++++++---------
bignum.h | 2 +-
2 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/bignum-random-prime.c b/bignum-random-prime.c
index 1fa7ee4a..dd772bdd 100644
--- a/bignum-random-prime.c
+++ b/bignum-random-prime.c
@@ -257,18 +257,17 @@ miller_rabin_pocklington(mpz_t n, mpz_t nm1, mpz_t nm1dq, mpz_t a)
p0 must be of size >= ceil(bits/2) + 1. The extra factor q can be
omitted. */
void
-_nettle_generate_pocklington_prime (mpz_t p, unsigned bits,
+_nettle_generate_pocklington_prime (mpz_t p, unsigned bits, mpz_t r,
void *ctx, nettle_random_func random,
const mpz_t p0,
const mpz_t q,
const mpz_t p0q)
{
- mpz_t i, r, pm1,a;
+ mpz_t i, pm1,a;
assert (2*mpz_sizeinbase (p0, 2) > bits + 1);
mpz_init (i);
- mpz_init (r);
mpz_init (pm1);
mpz_init (a);
@@ -304,13 +303,23 @@ _nettle_generate_pocklington_prime (mpz_t p, unsigned bits,
mpz_set_ui (a, buf[0] + 2);
if (q)
- mpz_mul (r, r, q);
-
- if (miller_rabin_pocklington(p, pm1, r, a))
+ {
+ mpz_t e;
+ int is_prime;
+
+ mpz_init (e);
+
+ mpz_mul (e, r, q);
+ is_prime = miller_rabin_pocklington(p, pm1, e, a);
+ mpz_clear (e);
+
+ if (is_prime)
+ break;
+ }
+ else if (miller_rabin_pocklington(p, pm1, r, a))
break;
}
mpz_clear (i);
- mpz_clear (r);
mpz_clear (pm1);
mpz_clear (a);
}
@@ -362,18 +371,20 @@ nettle_random_prime(mpz_t p, unsigned bits,
}
else
{
- mpz_t q;
+ mpz_t q, r;
mpz_init (q);
+ mpz_init (r);
/* Bit size ceil(k/2) + 1, slightly larger than used in Alg. 4.62
in Handbook of Applied Cryptography (which seems to be
incorrect for odd k). */
nettle_random_prime (q, (bits+3)/2, ctx, random);
- _nettle_generate_pocklington_prime (p, bits, ctx, random,
+ _nettle_generate_pocklington_prime (p, bits, r, ctx, random,
q, NULL, q);
mpz_clear (q);
+ mpz_clear (r);
}
}
diff --git a/bignum.h b/bignum.h
index 9db38825..0c40815c 100644
--- a/bignum.h
+++ b/bignum.h
@@ -90,7 +90,7 @@ nettle_random_prime(mpz_t p, unsigned bits,
void *ctx, nettle_random_func random);
void
-_nettle_generate_pocklington_prime (mpz_t p, unsigned bits,
+_nettle_generate_pocklington_prime (mpz_t p, unsigned bits, mpz_t r,
void *ctx, nettle_random_func random,
const mpz_t p0,
const mpz_t q,
--
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