diff options
Diffstat (limited to 'openssl-1.1.0h/crypto/dh/dh_check.c')
| -rw-r--r-- | openssl-1.1.0h/crypto/dh/dh_check.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/openssl-1.1.0h/crypto/dh/dh_check.c b/openssl-1.1.0h/crypto/dh/dh_check.c new file mode 100644 index 0000000..3b0fa59 --- /dev/null +++ b/openssl-1.1.0h/crypto/dh/dh_check.c @@ -0,0 +1,183 @@ +/* + * Copyright 1995-2016 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 + */ + +#include <stdio.h> +#include "internal/cryptlib.h" +#include <openssl/bn.h> +#include "dh_locl.h" + +/*- + * Check that p and g are suitable enough + * + * p is odd + * 1 < g < p - 1 + */ + +int DH_check_params(const DH *dh, int *ret) +{ + int ok = 0; + BIGNUM *tmp = NULL; + BN_CTX *ctx = NULL; + + *ret = 0; + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + tmp = BN_CTX_get(ctx); + if (tmp == NULL) + goto err; + + if (!BN_is_odd(dh->p)) + *ret |= DH_CHECK_P_NOT_PRIME; + if (BN_is_negative(dh->g) || BN_is_zero(dh->g) || BN_is_one(dh->g)) + *ret |= DH_NOT_SUITABLE_GENERATOR; + if (BN_copy(tmp, dh->p) == NULL || !BN_sub_word(tmp, 1)) + goto err; + if (BN_cmp(dh->g, tmp) >= 0) + *ret |= DH_NOT_SUITABLE_GENERATOR; + + ok = 1; + err: + if (ctx != NULL) { + BN_CTX_end(ctx); + BN_CTX_free(ctx); + } + return (ok); +} + +/*- + * Check that p is a safe prime and + * if g is 2, 3 or 5, check that it is a suitable generator + * where + * for 2, p mod 24 == 11 + * for 3, p mod 12 == 5 + * for 5, p mod 10 == 3 or 7 + * should hold. + */ + +int DH_check(const DH *dh, int *ret) +{ + int ok = 0, r; + BN_CTX *ctx = NULL; + BN_ULONG l; + BIGNUM *t1 = NULL, *t2 = NULL; + + *ret = 0; + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + t1 = BN_CTX_get(ctx); + if (t1 == NULL) + goto err; + t2 = BN_CTX_get(ctx); + if (t2 == NULL) + goto err; + + if (dh->q) { + if (BN_cmp(dh->g, BN_value_one()) <= 0) + *ret |= DH_NOT_SUITABLE_GENERATOR; + else if (BN_cmp(dh->g, dh->p) >= 0) + *ret |= DH_NOT_SUITABLE_GENERATOR; + else { + /* Check g^q == 1 mod p */ + if (!BN_mod_exp(t1, dh->g, dh->q, dh->p, ctx)) + goto err; + if (!BN_is_one(t1)) + *ret |= DH_NOT_SUITABLE_GENERATOR; + } + r = BN_is_prime_ex(dh->q, BN_prime_checks, ctx, NULL); + if (r < 0) + goto err; + if (!r) + *ret |= DH_CHECK_Q_NOT_PRIME; + /* Check p == 1 mod q i.e. q divides p - 1 */ + if (!BN_div(t1, t2, dh->p, dh->q, ctx)) + goto err; + if (!BN_is_one(t2)) + *ret |= DH_CHECK_INVALID_Q_VALUE; + if (dh->j && BN_cmp(dh->j, t1)) + *ret |= DH_CHECK_INVALID_J_VALUE; + + } else if (BN_is_word(dh->g, DH_GENERATOR_2)) { + l = BN_mod_word(dh->p, 24); + if (l == (BN_ULONG)-1) + goto err; + if (l != 11) + *ret |= DH_NOT_SUITABLE_GENERATOR; + } else if (BN_is_word(dh->g, DH_GENERATOR_5)) { + l = BN_mod_word(dh->p, 10); + if (l == (BN_ULONG)-1) + goto err; + if ((l != 3) && (l != 7)) + *ret |= DH_NOT_SUITABLE_GENERATOR; + } else + *ret |= DH_UNABLE_TO_CHECK_GENERATOR; + + r = BN_is_prime_ex(dh->p, BN_prime_checks, ctx, NULL); + if (r < 0) + goto err; + if (!r) + *ret |= DH_CHECK_P_NOT_PRIME; + else if (!dh->q) { + if (!BN_rshift1(t1, dh->p)) + goto err; + r = BN_is_prime_ex(t1, BN_prime_checks, ctx, NULL); + if (r < 0) + goto err; + if (!r) + *ret |= DH_CHECK_P_NOT_SAFE_PRIME; + } + ok = 1; + err: + if (ctx != NULL) { + BN_CTX_end(ctx); + BN_CTX_free(ctx); + } + return (ok); +} + +int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret) +{ + int ok = 0; + BIGNUM *tmp = NULL; + BN_CTX *ctx = NULL; + + *ret = 0; + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + tmp = BN_CTX_get(ctx); + if (tmp == NULL || !BN_set_word(tmp, 1)) + goto err; + if (BN_cmp(pub_key, tmp) <= 0) + *ret |= DH_CHECK_PUBKEY_TOO_SMALL; + if (BN_copy(tmp, dh->p) == NULL || !BN_sub_word(tmp, 1)) + goto err; + if (BN_cmp(pub_key, tmp) >= 0) + *ret |= DH_CHECK_PUBKEY_TOO_LARGE; + + if (dh->q != NULL) { + /* Check pub_key^q == 1 mod p */ + if (!BN_mod_exp(tmp, pub_key, dh->q, dh->p, ctx)) + goto err; + if (!BN_is_one(tmp)) + *ret |= DH_CHECK_PUBKEY_INVALID; + } + + ok = 1; + err: + if (ctx != NULL) { + BN_CTX_end(ctx); + BN_CTX_free(ctx); + } + return (ok); +} |