From f11f86f6ec7fb31bde1da2810ac975c032205321 Mon Sep 17 00:00:00 2001 From: Shane Lontis Date: Thu, 6 Feb 2020 22:28:36 +1000 Subject: Add FFC param/key generation Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/10909) --- crypto/ffc/ffc_key_generate.c | 61 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 crypto/ffc/ffc_key_generate.c (limited to 'crypto/ffc/ffc_key_generate.c') diff --git a/crypto/ffc/ffc_key_generate.c b/crypto/ffc/ffc_key_generate.c new file mode 100644 index 0000000000..186245cc87 --- /dev/null +++ b/crypto/ffc/ffc_key_generate.c @@ -0,0 +1,61 @@ +/* + * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the Apache License 2.0 (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 + */ + +#include "internal/ffc.h" + +/* + * SP800-56Ar3 5.6.1.1.4 Key pair generation by testing candidates. + * Generates a private key in the interval [1, min(2 ^ N - 1, q - 1)]. + * + * ctx must be set up with a libctx (for fips mode). + * params contains the FFC domain parameters p, q and g (for DH or DSA). + * N is the maximum bit length of the generated private key, + * s is the security strength. + * priv_key is the returned private key, + */ +int ffc_generate_private_key(BN_CTX *ctx, const FFC_PARAMS *params, + int N, int s, BIGNUM *priv) +{ +#ifdef FIPS_MODE + int ret = 0; + BIGNUM *m, *two_powN = NULL; + + /* Step (2) : check range of N */ + if (N < 2 * s || N > BN_num_bits(params->q)) + return 0; + + two_powN = BN_new(); + /* 2^N */ + if (two_powN == NULL || !BN_lshift(two_powN, BN_value_one(), N)) + goto err; + + /* Step (5) : M = min(2 ^ N, q) */ + m = (BN_cmp(two_powN, params->q) > 0) ? params->q : two_powN; + do { + /* Steps (3, 4 & 7) : c + 1 = 1 + random[0..2^N - 1] */ + if (!BN_priv_rand_range_ex(priv, two_powN, ctx) + || !BN_add_word(priv, 1)) + goto err; + /* Step (6) : loop if c > M - 2 (i.e. c + 1 >= M) */ + if (BN_cmp(priv, m) < 0) + break; + } while (1); + + ret = 1; +err: + BN_free(two_powN); + return ret; +#else + do { + if (!BN_priv_rand_range_ex(priv, params->q, ctx)) + return 0; + } while (BN_is_zero(priv) || BN_is_one(priv)); + return 1; +#endif /* FIPS_MODE */ +} -- cgit v1.2.3