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Imported OpenSSL 1.1.1d

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This commit is contained in:
Steve Dower
2019-09-16 11:16:33 +01:00
parent ea3c37b9ec
commit 6f2f71e7ea
325 changed files with 5375 additions and 11047 deletions
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54
crypto/dh/dh_gen.c
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@@ -30,30 +30,33 @@ int DH_generate_parameters_ex(DH *ret, int prime_len, int generator,
/*-
* We generate DH parameters as follows
* find a prime q which is prime_len/2 bits long.
* p=(2*q)+1 or (p-1)/2 = q
* For this case, g is a generator if
* g^((p-1)/q) mod p != 1 for values of q which are the factors of p-1.
* Since the factors of p-1 are q and 2, we just need to check
* g^2 mod p != 1 and g^q mod p != 1.
* find a prime p which is prime_len bits long,
* where q=(p-1)/2 is also prime.
* In the following we assume that g is not 0, 1 or p-1, since it
* would generate only trivial subgroups.
* For this case, g is a generator of the order-q subgroup if
* g^q mod p == 1.
* Or in terms of the Legendre symbol: (g/p) == 1.
*
* Having said all that,
* there is another special case method for the generators 2, 3 and 5.
* Using the quadratic reciprocity law it is possible to solve
* (g/p) == 1 for the special values 2, 3, 5:
* (2/p) == 1 if p mod 8 == 1 or 7.
* (3/p) == 1 if p mod 12 == 1 or 11.
* (5/p) == 1 if p mod 5 == 1 or 4.
* See for instance: https://en.wikipedia.org/wiki/Legendre_symbol
*
* Since all safe primes > 7 must satisfy p mod 12 == 11
* and all safe primes > 11 must satisfy p mod 5 != 1
* we can further improve the condition for g = 2, 3 and 5:
* for 2, p mod 24 == 23
* for 3, p mod 12 == 11
* for 5, p mod 60 == 59
*
* However for compatibilty with previous versions we use:
* for 2, p mod 24 == 11
* for 3, p mod 12 == 5 <<<<< does not work for safe primes.
* for 5, p mod 10 == 3 or 7
*
* Thanks to Phil Karn for the pointers about the
* special generators and for answering some of my questions.
*
* I've implemented the second simple method :-).
* Since DH should be using a safe prime (both p and q are prime),
* this generator function can take a very very long time to run.
*/
/*
* Actually there is no reason to insist that 'generator' be a generator.
* It's just as OK (and in some sense better) to use a generator of the
* order-q subgroup.
* for 5, p mod 60 == 23
*/
static int dh_builtin_genparams(DH *ret, int prime_len, int generator,
BN_GENCB *cb)
@@ -88,13 +91,10 @@ static int dh_builtin_genparams(DH *ret, int prime_len, int generator,
goto err;
g = 2;
} else if (generator == DH_GENERATOR_5) {
if (!BN_set_word(t1, 10))
if (!BN_set_word(t1, 60))
goto err;
if (!BN_set_word(t2, 3))
if (!BN_set_word(t2, 23))
goto err;
/*
* BN_set_word(t3,7); just have to miss out on these ones :-(
*/
g = 5;
} else {
/*
@@ -102,9 +102,9 @@ static int dh_builtin_genparams(DH *ret, int prime_len, int generator,
* not: since we are using safe primes, it will generate either an
* order-q or an order-2q group, which both is OK
*/
if (!BN_set_word(t1, 2))
if (!BN_set_word(t1, 12))
goto err;
if (!BN_set_word(t2, 1))
if (!BN_set_word(t2, 11))
goto err;
g = generator;
}