text: /*
   * Copyright 1995-2020 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
   */
  
  #ifndef OPENSSL_DH_H
  # define OPENSSL_DH_H
  # pragma once
  
  # include <openssl/macros.h>
  # ifndef OPENSSL_NO_DEPRECATED_3_0
  #  define HEADER_DH_H
  # endif
  
  # include <openssl/opensslconf.h>
  # include <openssl/types.h>
  
  # ifdef  __cplusplus
  extern "C" {
  # endif
  
  #include <stdlib.h>
  
  /* DH parameter generation types used by EVP_PKEY_CTX_set_dh_paramgen_type() */
  # define DH_PARAMGEN_TYPE_GENERATOR     0   /* Use a safe prime generator */
  # define DH_PARAMGEN_TYPE_FIPS_186_2    1   /* Use FIPS186-2 standard */
  # define DH_PARAMGEN_TYPE_FIPS_186_4    2   /* Use FIPS186-4 standard */
  # define DH_PARAMGEN_TYPE_GROUP         3   /* Use a named safe prime group */
  
  int EVP_PKEY_CTX_set_dh_paramgen_type(EVP_PKEY_CTX *ctx, int typ);
  int EVP_PKEY_CTX_set_dh_paramgen_gindex(EVP_PKEY_CTX *ctx, int gindex);
  int EVP_PKEY_CTX_set_dh_paramgen_seed(EVP_PKEY_CTX *ctx,
                                        const unsigned char *seed,
                                        size_t seedlen);
  int EVP_PKEY_CTX_set_dh_paramgen_prime_len(EVP_PKEY_CTX *ctx, int pbits);
  int EVP_PKEY_CTX_set_dh_paramgen_subprime_len(EVP_PKEY_CTX *ctx, int qlen);
  int EVP_PKEY_CTX_set_dh_paramgen_generator(EVP_PKEY_CTX *ctx, int gen);
  int EVP_PKEY_CTX_set_dh_nid(EVP_PKEY_CTX *ctx, int nid);
  int EVP_PKEY_CTX_set_dh_rfc5114(EVP_PKEY_CTX *ctx, int gen);
  int EVP_PKEY_CTX_set_dhx_rfc5114(EVP_PKEY_CTX *ctx, int gen);
  int EVP_PKEY_CTX_set_dh_pad(EVP_PKEY_CTX *ctx, int pad);
  
  int EVP_PKEY_CTX_set_dh_kdf_type(EVP_PKEY_CTX *ctx, int kdf);
  int EVP_PKEY_CTX_get_dh_kdf_type(EVP_PKEY_CTX *ctx);
  int EVP_PKEY_CTX_set0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT *oid);
  int EVP_PKEY_CTX_get0_dh_kdf_oid(EVP_PKEY_CTX *ctx, ASN1_OBJECT **oid);
  int EVP_PKEY_CTX_set_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD *md);
  int EVP_PKEY_CTX_get_dh_kdf_md(EVP_PKEY_CTX *ctx, const EVP_MD **md);
  int EVP_PKEY_CTX_set_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int len);
  int EVP_PKEY_CTX_get_dh_kdf_outlen(EVP_PKEY_CTX *ctx, int *len);
  int EVP_PKEY_CTX_set0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len);
  # ifndef OPENSSL_NO_DEPRECATED_3_0
  OSSL_DEPRECATEDIN_3_0
  int EVP_PKEY_CTX_get0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char **ukm);
  #endif
  
  # define EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN     (EVP_PKEY_ALG_CTRL + 1)
  # define EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR     (EVP_PKEY_ALG_CTRL + 2)
  # define EVP_PKEY_CTRL_DH_RFC5114                (EVP_PKEY_ALG_CTRL + 3)
  # define EVP_PKEY_CTRL_DH_PARAMGEN_SUBPRIME_LEN  (EVP_PKEY_ALG_CTRL + 4)
  # define EVP_PKEY_CTRL_DH_PARAMGEN_TYPE          (EVP_PKEY_ALG_CTRL + 5)
  # define EVP_PKEY_CTRL_DH_KDF_TYPE               (EVP_PKEY_ALG_CTRL + 6)
  # define EVP_PKEY_CTRL_DH_KDF_MD                 (EVP_PKEY_ALG_CTRL + 7)
  # define EVP_PKEY_CTRL_GET_DH_KDF_MD             (EVP_PKEY_ALG_CTRL + 8)
  # define EVP_PKEY_CTRL_DH_KDF_OUTLEN             (EVP_PKEY_ALG_CTRL + 9)
  # define EVP_PKEY_CTRL_GET_DH_KDF_OUTLEN         (EVP_PKEY_ALG_CTRL + 10)
  # define EVP_PKEY_CTRL_DH_KDF_UKM                (EVP_PKEY_ALG_CTRL + 11)
  # define EVP_PKEY_CTRL_GET_DH_KDF_UKM            (EVP_PKEY_ALG_CTRL + 12)
  # define EVP_PKEY_CTRL_DH_KDF_OID                (EVP_PKEY_ALG_CTRL + 13)
  # define EVP_PKEY_CTRL_GET_DH_KDF_OID            (EVP_PKEY_ALG_CTRL + 14)
  # define EVP_PKEY_CTRL_DH_NID                    (EVP_PKEY_ALG_CTRL + 15)
  # define EVP_PKEY_CTRL_DH_PAD                    (EVP_PKEY_ALG_CTRL + 16)
  
  /* KDF types */
  # define EVP_PKEY_DH_KDF_NONE                            1
  # define EVP_PKEY_DH_KDF_X9_42                           2
  
  # ifndef OPENSSL_NO_DH
  #  include <openssl/e_os2.h>
  #  include <openssl/bio.h>
  #  include <openssl/asn1.h>
  #  ifndef OPENSSL_NO_DEPRECATED_1_1_0
  #   include <openssl/bn.h>
  #  endif
  #  include <openssl/dherr.h>
  
  #  ifndef OPENSSL_DH_MAX_MODULUS_BITS
  #   define OPENSSL_DH_MAX_MODULUS_BITS    10000
  #  endif
  
  #  define OPENSSL_DH_FIPS_MIN_MODULUS_BITS 1024
  
  #  define DH_FLAG_CACHE_MONT_P     0x01
  
  #  define DH_FLAG_TYPE_MASK             0xF000
  #  define DH_FLAG_TYPE_DH               0x0000
  #  define DH_FLAG_TYPE_DHX              0x1000
  
  #  ifndef OPENSSL_NO_DEPRECATED_1_1_0
  /*
   * Does nothing. Previously this switched off constant time behaviour.
   */
  #   define DH_FLAG_NO_EXP_CONSTTIME 0x00
  #  endif
  
  #  ifndef OPENSSL_NO_DEPRECATED_3_0
  /*
   * If this flag is set the DH method is FIPS compliant and can be used in
   * FIPS mode. This is set in the validated module method. If an application
   * sets this flag in its own methods it is its responsibility to ensure the
   * result is compliant.
   */
  
  #   define DH_FLAG_FIPS_METHOD                     0x0400
  
  /*
   * If this flag is set the operations normally disabled in FIPS mode are
   * permitted it is then the applications responsibility to ensure that the
   * usage is compliant.
   */
  
  #   define DH_FLAG_NON_FIPS_ALLOW                  0x0400
  #  endif
  
  /* Already defined in ossl_typ.h */
  /* typedef struct dh_st DH; */
  /* typedef struct dh_method DH_METHOD; */
  
  DECLARE_ASN1_ITEM(DHparams)
  
  #  ifndef OPENSSL_NO_DEPRECATED_3_0
  #   define DH_GENERATOR_2          2
  #   define DH_GENERATOR_3          3
  #   define DH_GENERATOR_5          5
  
  /* DH_check error codes */
  /*
   * NB: These values must align with the equivalently named macros in
   * internal/ffc.h.
   */
  #   define DH_CHECK_P_NOT_PRIME            0x01
  #   define DH_CHECK_P_NOT_SAFE_PRIME       0x02
  #   define DH_UNABLE_TO_CHECK_GENERATOR    0x04
  #   define DH_NOT_SUITABLE_GENERATOR       0x08
  #   define DH_CHECK_Q_NOT_PRIME            0x10
  #   define DH_CHECK_INVALID_Q_VALUE        0x20
  #   define DH_CHECK_INVALID_J_VALUE        0x40
  #   define DH_MODULUS_TOO_SMALL            0x80
  #   define DH_MODULUS_TOO_LARGE            0x100
  
  /* DH_check_pub_key error codes */
  #   define DH_CHECK_PUBKEY_TOO_SMALL       0x01
  #   define DH_CHECK_PUBKEY_TOO_LARGE       0x02
  #   define DH_CHECK_PUBKEY_INVALID         0x04
  
  /*
   * primes p where (p-1)/2 is prime too are called "safe"; we define this for
   * backward compatibility:
   */
  #   define DH_CHECK_P_NOT_STRONG_PRIME     DH_CHECK_P_NOT_SAFE_PRIME
  
  #   define d2i_DHparams_fp(fp, x) \
          (DH *)ASN1_d2i_fp((char *(*)())DH_new, \
                            (char *(*)())d2i_DHparams, \
                            (fp), \
                            (unsigned char **)(x))
  #   define i2d_DHparams_fp(fp, x) \
          ASN1_i2d_fp(i2d_DHparams,(fp), (unsigned char *)(x))
  #   define d2i_DHparams_bio(bp, x) \
          ASN1_d2i_bio_of(DH, DH_new, d2i_DHparams, bp, x)
  #   define i2d_DHparams_bio(bp, x) \
          ASN1_i2d_bio_of(DH, i2d_DHparams, bp, x)
  
  #   define d2i_DHxparams_fp(fp,x) \
          (DH *)ASN1_d2i_fp((char *(*)())DH_new, \
                            (char *(*)())d2i_DHxparams, \
                            (fp), \
                            (unsigned char **)(x))
  #   define i2d_DHxparams_fp(fp, x) \
          ASN1_i2d_fp(i2d_DHxparams,(fp), (unsigned char *)(x))
  #   define d2i_DHxparams_bio(bp, x) \
          ASN1_d2i_bio_of(DH, DH_new, d2i_DHxparams, bp, x)
  #   define i2d_DHxparams_bio(bp, x) \
          ASN1_i2d_bio_of(DH, i2d_DHxparams, bp, x)
  
  DECLARE_ASN1_DUP_FUNCTION_name_attr(OSSL_DEPRECATEDIN_3_0, DH, DHparams)
  
  OSSL_DEPRECATEDIN_3_0 const DH_METHOD *DH_OpenSSL(void);
  
  OSSL_DEPRECATEDIN_3_0 void DH_set_default_method(const DH_METHOD *meth);
  OSSL_DEPRECATEDIN_3_0 const DH_METHOD *DH_get_default_method(void);
  OSSL_DEPRECATEDIN_3_0 int DH_set_method(DH *dh, const DH_METHOD *meth);
  OSSL_DEPRECATEDIN_3_0 DH *DH_new_method(ENGINE *engine);
  
  OSSL_DEPRECATEDIN_3_0 DH *DH_new(void);
  OSSL_DEPRECATEDIN_3_0 void DH_free(DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_up_ref(DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_bits(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_size(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_security_bits(const DH *dh);
  
  #   define DH_get_ex_new_index(l, p, newf, dupf, freef) \
          CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, l, p, newf, dupf, freef)
  
  OSSL_DEPRECATEDIN_3_0 int DH_set_ex_data(DH *d, int idx, void *arg);
  OSSL_DEPRECATEDIN_3_0 void *DH_get_ex_data(const DH *d, int idx);
  
  OSSL_DEPRECATEDIN_3_0 int DH_generate_parameters_ex(DH *dh, int prime_len,
                                                      int generator,
                                                      BN_GENCB *cb);
  
  OSSL_DEPRECATEDIN_3_0 int DH_check_params_ex(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_check_ex(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_check_pub_key_ex(const DH *dh, const BIGNUM *pub_key);
  OSSL_DEPRECATEDIN_3_0 int DH_check_params(const DH *dh, int *ret);
  OSSL_DEPRECATEDIN_3_0 int DH_check(const DH *dh, int *codes);
  OSSL_DEPRECATEDIN_3_0 int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key,
                                             int *codes);
  OSSL_DEPRECATEDIN_3_0 int DH_generate_key(DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_compute_key(unsigned char *key,
                                           const BIGNUM *pub_key, DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_compute_key_padded(unsigned char *key,
                                                  const BIGNUM *pub_key, DH *dh);
  
  DECLARE_ASN1_ENCODE_FUNCTIONS_only_attr(OSSL_DEPRECATEDIN_3_0, DH, DHparams)
  DECLARE_ASN1_ENCODE_FUNCTIONS_only_attr(OSSL_DEPRECATEDIN_3_0, DH, DHxparams)
  
  #   ifndef OPENSSL_NO_STDIO
  OSSL_DEPRECATEDIN_3_0 int DHparams_print_fp(FILE *fp, const DH *x);
  #   endif
  OSSL_DEPRECATEDIN_3_0 int DHparams_print(BIO *bp, const DH *x);
  
  /* RFC 5114 parameters */
  OSSL_DEPRECATEDIN_3_0 DH *DH_get_1024_160(void);
  OSSL_DEPRECATEDIN_3_0 DH *DH_get_2048_224(void);
  OSSL_DEPRECATEDIN_3_0 DH *DH_get_2048_256(void);
  
  /* Named parameters, currently RFC7919 and RFC3526 */
  OSSL_DEPRECATEDIN_3_0 DH *DH_new_by_nid(int nid);
  OSSL_DEPRECATEDIN_3_0 int DH_get_nid(const DH *dh);
  
  /* RFC2631 KDF */
  OSSL_DEPRECATEDIN_3_0 int DH_KDF_X9_42(unsigned char *out, size_t outlen,
                                         const unsigned char *Z, size_t Zlen,
                                         ASN1_OBJECT *key_oid,
                                         const unsigned char *ukm,
                                         size_t ukmlen, const EVP_MD *md);
  
  OSSL_DEPRECATEDIN_3_0 void DH_get0_pqg(const DH *dh, const BIGNUM **p,
                                         const BIGNUM **q, const BIGNUM **g);
  OSSL_DEPRECATEDIN_3_0 int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g);
  OSSL_DEPRECATEDIN_3_0 void DH_get0_key(const DH *dh, const BIGNUM **pub_key,
                                         const BIGNUM **priv_key);
  OSSL_DEPRECATEDIN_3_0 int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key);
  OSSL_DEPRECATEDIN_3_0 const BIGNUM *DH_get0_p(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 const BIGNUM *DH_get0_q(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 const BIGNUM *DH_get0_g(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 const BIGNUM *DH_get0_priv_key(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 const BIGNUM *DH_get0_pub_key(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 void DH_clear_flags(DH *dh, int flags);
  OSSL_DEPRECATEDIN_3_0 int DH_test_flags(const DH *dh, int flags);
  OSSL_DEPRECATEDIN_3_0 void DH_set_flags(DH *dh, int flags);
  OSSL_DEPRECATEDIN_3_0 ENGINE *DH_get0_engine(DH *d);
  OSSL_DEPRECATEDIN_3_0 long DH_get_length(const DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_set_length(DH *dh, long length);
  
  OSSL_DEPRECATEDIN_3_0 DH_METHOD *DH_meth_new(const char *name, int flags);
  OSSL_DEPRECATEDIN_3_0 void DH_meth_free(DH_METHOD *dhm);
  OSSL_DEPRECATEDIN_3_0 DH_METHOD *DH_meth_dup(const DH_METHOD *dhm);
  OSSL_DEPRECATEDIN_3_0 const char *DH_meth_get0_name(const DH_METHOD *dhm);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set1_name(DH_METHOD *dhm, const char *name);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_get_flags(const DH_METHOD *dhm);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_flags(DH_METHOD *dhm, int flags);
  OSSL_DEPRECATEDIN_3_0 void *DH_meth_get0_app_data(const DH_METHOD *dhm);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set0_app_data(DH_METHOD *dhm, void *app_data);
  OSSL_DEPRECATEDIN_3_0 int (*DH_meth_get_generate_key(const DH_METHOD *dhm)) (DH *);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_generate_key(DH_METHOD *dhm,
                                                     int (*generate_key) (DH *));
  OSSL_DEPRECATEDIN_3_0 int (*DH_meth_get_compute_key(const DH_METHOD *dhm))
                                                     (unsigned char *key,
                                                      const BIGNUM *pub_key,
                                                      DH *dh);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_compute_key(DH_METHOD *dhm,
                                                    int (*compute_key)
                                                    (unsigned char *key,
                                                     const BIGNUM *pub_key,
                                                     DH *dh));
  OSSL_DEPRECATEDIN_3_0 int (*DH_meth_get_bn_mod_exp(const DH_METHOD *dhm))
                                                     (const DH *, BIGNUM *,
                                                      const BIGNUM *,
                                                      const BIGNUM *,
                                                      const BIGNUM *, BN_CTX *,
                                                      BN_MONT_CTX *);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_bn_mod_exp(DH_METHOD *dhm,
                                                   int (*bn_mod_exp)
                                                   (const DH *, BIGNUM *,
                                                    const BIGNUM *, const BIGNUM *,
                                                    const BIGNUM *, BN_CTX *,
                                                    BN_MONT_CTX *));
  OSSL_DEPRECATEDIN_3_0 int (*DH_meth_get_init(const DH_METHOD *dhm))(DH *);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_init(DH_METHOD *dhm, int (*init)(DH *));
  OSSL_DEPRECATEDIN_3_0 int (*DH_meth_get_finish(const DH_METHOD *dhm)) (DH *);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_finish(DH_METHOD *dhm, int (*finish) (DH *));
  OSSL_DEPRECATEDIN_3_0 int (*DH_meth_get_generate_params(const DH_METHOD *dhm))
                                                          (DH *, int, int,
                                                           BN_GENCB *);
  OSSL_DEPRECATEDIN_3_0 int DH_meth_set_generate_params(DH_METHOD *dhm,
                                                        int (*generate_params)
                                                        (DH *, int, int,
                                                         BN_GENCB *));
  #  endif /* OPENSSL_NO_DEPRECATED_3_0 */
  
  #  ifndef OPENSSL_NO_DEPRECATED_0_9_8
  OSSL_DEPRECATEDIN_0_9_8 DH *DH_generate_parameters(int prime_len, int generator,
                                                     void (*callback) (int, int,
                                                                  void *),
                                                     void *cb_arg);
  #  endif
  
  # endif
  # ifdef  __cplusplus
  }
  # endif
  #endif
  