| # This file is dual licensed under the terms of the Apache License, Version |
| # 2.0, and the BSD License. See the LICENSE file in the root of this repository |
| # for complete details. |
| |
| from __future__ import absolute_import, division, print_function |
| |
| INCLUDES = """ |
| #include <openssl/dh.h> |
| """ |
| |
| TYPES = """ |
| typedef ... DH; |
| |
| const long DH_NOT_SUITABLE_GENERATOR; |
| """ |
| |
| FUNCTIONS = """ |
| DH *DH_new(void); |
| void DH_free(DH *); |
| int DH_size(const DH *); |
| int DH_generate_key(DH *); |
| int DH_compute_key(unsigned char *, const BIGNUM *, DH *); |
| DH *DHparams_dup(DH *); |
| |
| /* added in 1.1.0 when the DH struct was opaqued */ |
| void DH_get0_pqg(const DH *, const BIGNUM **, const BIGNUM **, |
| const BIGNUM **); |
| int DH_set0_pqg(DH *, BIGNUM *, BIGNUM *, BIGNUM *); |
| void DH_get0_key(const DH *, const BIGNUM **, const BIGNUM **); |
| int DH_set0_key(DH *, BIGNUM *, BIGNUM *); |
| |
| int Cryptography_DH_check(const DH *, int *); |
| int DH_generate_parameters_ex(DH *, int, int, BN_GENCB *); |
| DH *d2i_DHparams_bio(BIO *, DH **); |
| int i2d_DHparams_bio(BIO *, DH *); |
| DH *Cryptography_d2i_DHxparams_bio(BIO *bp, DH **x); |
| int Cryptography_i2d_DHxparams_bio(BIO *bp, DH *x); |
| """ |
| |
| CUSTOMIZATIONS = """ |
| #if CRYPTOGRAPHY_IS_LIBRESSL |
| #ifndef DH_CHECK_Q_NOT_PRIME |
| #define DH_CHECK_Q_NOT_PRIME 0x10 |
| #endif |
| |
| #ifndef DH_CHECK_INVALID_Q_VALUE |
| #define DH_CHECK_INVALID_Q_VALUE 0x20 |
| #endif |
| |
| #ifndef DH_CHECK_INVALID_J_VALUE |
| #define DH_CHECK_INVALID_J_VALUE 0x40 |
| #endif |
| |
| /* DH_check implementation taken from OpenSSL 1.1.0pre6 */ |
| |
| /*- |
| * 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 Cryptography_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); |
| } |
| #else |
| int Cryptography_DH_check(const DH *dh, int *ret) { |
| return DH_check(dh, ret); |
| } |
| #endif |
| |
| /* These functions were added in OpenSSL 1.1.0f commit d0c50e80a8 */ |
| /* Define our own to simplify support across all versions. */ |
| #if defined(EVP_PKEY_DHX) && EVP_PKEY_DHX != -1 |
| DH *Cryptography_d2i_DHxparams_bio(BIO *bp, DH **x) { |
| return ASN1_d2i_bio_of(DH, DH_new, d2i_DHxparams, bp, x); |
| } |
| int Cryptography_i2d_DHxparams_bio(BIO *bp, DH *x) { |
| return ASN1_i2d_bio_of_const(DH, i2d_DHxparams, bp, x); |
| } |
| #else |
| DH *(*Cryptography_d2i_DHxparams_bio)(BIO *bp, DH **x) = NULL; |
| int (*Cryptography_i2d_DHxparams_bio)(BIO *bp, DH *x) = NULL; |
| #endif |
| """ |