diff options
Diffstat (limited to 'roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/dh/dh_gen.c')
| -rw-r--r-- | roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/dh/dh_gen.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/dh/dh_gen.c b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/dh/dh_gen.c new file mode 100644 index 000000000..ab82ab58b --- /dev/null +++ b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/crypto/dh/dh_gen.c @@ -0,0 +1,128 @@ +/* + * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +/* + * NB: These functions have been upgraded - the previous prototypes are in + * dh_depr.c as wrappers to these ones. - Geoff + */ + +#include <stdio.h> +#include "internal/cryptlib.h" +#include <openssl/bn.h> +#include "dh_local.h" + +static int dh_builtin_genparams(DH *ret, int prime_len, int generator, + BN_GENCB *cb); + +int DH_generate_parameters_ex(DH *ret, int prime_len, int generator, + BN_GENCB *cb) +{ + if (ret->meth->generate_params) + return ret->meth->generate_params(ret, prime_len, generator, cb); + return dh_builtin_genparams(ret, prime_len, generator, cb); +} + +/*- + * We generate DH parameters as follows + * 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 compatibility with previous versions we use: + * for 2, p mod 24 == 11 + * for 5, p mod 60 == 23 + */ +static int dh_builtin_genparams(DH *ret, int prime_len, int generator, + BN_GENCB *cb) +{ + BIGNUM *t1, *t2; + int g, ok = -1; + BN_CTX *ctx = NULL; + + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + t1 = BN_CTX_get(ctx); + t2 = BN_CTX_get(ctx); + if (t2 == NULL) + goto err; + + /* Make sure 'ret' has the necessary elements */ + if (!ret->p && ((ret->p = BN_new()) == NULL)) + goto err; + if (!ret->g && ((ret->g = BN_new()) == NULL)) + goto err; + + if (generator <= 1) { + DHerr(DH_F_DH_BUILTIN_GENPARAMS, DH_R_BAD_GENERATOR); + goto err; + } + if (generator == DH_GENERATOR_2) { + if (!BN_set_word(t1, 24)) + goto err; + if (!BN_set_word(t2, 11)) + goto err; + g = 2; + } else if (generator == DH_GENERATOR_5) { + if (!BN_set_word(t1, 60)) + goto err; + if (!BN_set_word(t2, 23)) + goto err; + g = 5; + } else { + /* + * in the general case, don't worry if 'generator' is a generator or + * 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, 12)) + goto err; + if (!BN_set_word(t2, 11)) + goto err; + g = generator; + } + + if (!BN_generate_prime_ex(ret->p, prime_len, 1, t1, t2, cb)) + goto err; + if (!BN_GENCB_call(cb, 3, 0)) + goto err; + if (!BN_set_word(ret->g, g)) + goto err; + ok = 1; + err: + if (ok == -1) { + DHerr(DH_F_DH_BUILTIN_GENPARAMS, ERR_R_BN_LIB); + ok = 0; + } + + BN_CTX_end(ctx); + BN_CTX_free(ctx); + return ok; +} |