text: /* crypto/dsa/dsa.h */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  /*
   * The DSS routines are based on patches supplied by
   * Steven Schoch <schoch@sheba.arc.nasa.gov>.  He basically did the
   * work and I have just tweaked them a little to fit into my
   * stylistic vision for SSLeay :-) */
  
  #ifndef HEADER_DSA_H
  # define HEADER_DSA_H
  
  # include <e_os2.h>
  
  # ifdef OPENSSL_NO_DSA
  #  error DSA is disabled.
  # endif
  
  # ifndef OPENSSL_NO_BIO
  #  include <bio.h>
  # endif
  # include <crypto.h>
  # include <ossl_typ.h>
  
  # ifndef OPENSSL_NO_DEPRECATED
  #  include <bn.h>
  #  ifndef OPENSSL_NO_DH
  #   include <dh.h>
  #  endif
  # endif
  
  # ifndef OPENSSL_DSA_MAX_MODULUS_BITS
  #  define OPENSSL_DSA_MAX_MODULUS_BITS   10000
  # endif
  
  # define DSA_FLAG_CACHE_MONT_P   0x01
  /*
   * new with 0.9.7h; the built-in DSA implementation now uses constant time
   * modular exponentiation for secret exponents by default. This flag causes
   * the faster variable sliding window method to be used for all exponents.
   */
  # define DSA_FLAG_NO_EXP_CONSTTIME       0x02
  
  /*
   * If this flag is set the DSA 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 reposibility to ensure the
   * result is compliant.
   */
  
  # define DSA_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 DSA_FLAG_NON_FIPS_ALLOW                 0x0400
  
  #ifdef  __cplusplus
  extern "C" {
  #endif
  
  /* Already defined in ossl_typ.h */
  /* typedef struct dsa_st DSA; */
  /* typedef struct dsa_method DSA_METHOD; */
  
  typedef struct DSA_SIG_st {
      BIGNUM *r;
      BIGNUM *s;
  } DSA_SIG;
  
  struct dsa_method {
      const char *name;
      DSA_SIG *(*dsa_do_sign) (const unsigned char *dgst, int dlen, DSA *dsa);
      int (*dsa_sign_setup) (DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
                             BIGNUM **rp);
      int (*dsa_do_verify) (const unsigned char *dgst, int dgst_len,
                            DSA_SIG *sig, DSA *dsa);
      int (*dsa_mod_exp) (DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
                          BIGNUM *a2, BIGNUM *p2, BIGNUM *m, BN_CTX *ctx,
                          BN_MONT_CTX *in_mont);
      /* Can be null */
      int (*bn_mod_exp) (DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
                         const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
      int (*init) (DSA *dsa);
      int (*finish) (DSA *dsa);
      int flags;
      char *app_data;
      /* If this is non-NULL, it is used to generate DSA parameters */
      int (*dsa_paramgen) (DSA *dsa, int bits,
                           const unsigned char *seed, int seed_len,
                           int *counter_ret, unsigned long *h_ret,
                           BN_GENCB *cb);
      /* If this is non-NULL, it is used to generate DSA keys */
      int (*dsa_keygen) (DSA *dsa);
  };
  
  struct dsa_st {
      /*
       * This first variable is used to pick up errors where a DSA is passed
       * instead of of a EVP_PKEY
       */
      int pad;
      long version;
      int write_params;
      BIGNUM *p;
      BIGNUM *q;                  /* == 20 */
      BIGNUM *g;
      BIGNUM *pub_key;            /* y public key */
      BIGNUM *priv_key;           /* x private key */
      BIGNUM *kinv;               /* Signing pre-calc */
      BIGNUM *r;                  /* Signing pre-calc */
      int flags;
      /* Normally used to cache montgomery values */
      BN_MONT_CTX *method_mont_p;
      int references;
      CRYPTO_EX_DATA ex_data;
      const DSA_METHOD *meth;
      /* functional reference if 'meth' is ENGINE-provided */
      ENGINE *engine;
  };
  
  # define d2i_DSAparams_fp(fp,x) (DSA *)ASN1_d2i_fp((char *(*)())DSA_new, \
                  (char *(*)())d2i_DSAparams,(fp),(unsigned char **)(x))
  # define i2d_DSAparams_fp(fp,x) ASN1_i2d_fp(i2d_DSAparams,(fp), \
                  (unsigned char *)(x))
  # define d2i_DSAparams_bio(bp,x) ASN1_d2i_bio_of(DSA,DSA_new,d2i_DSAparams,bp,x)
  # define i2d_DSAparams_bio(bp,x) ASN1_i2d_bio_of_const(DSA,i2d_DSAparams,bp,x)
  
  DSA *DSAparams_dup(DSA *x);
  DSA_SIG *DSA_SIG_new(void);
  void DSA_SIG_free(DSA_SIG *a);
  int i2d_DSA_SIG(const DSA_SIG *a, unsigned char **pp);
  DSA_SIG *d2i_DSA_SIG(DSA_SIG **v, const unsigned char **pp, long length);
  
  DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
  int DSA_do_verify(const unsigned char *dgst, int dgst_len,
                    DSA_SIG *sig, DSA *dsa);
  
  const DSA_METHOD *DSA_OpenSSL(void);
  
  void DSA_set_default_method(const DSA_METHOD *);
  const DSA_METHOD *DSA_get_default_method(void);
  int DSA_set_method(DSA *dsa, const DSA_METHOD *);
  
  DSA *DSA_new(void);
  DSA *DSA_new_method(ENGINE *engine);
  void DSA_free(DSA *r);
  /* "up" the DSA object's reference count */
  int DSA_up_ref(DSA *r);
  int DSA_size(const DSA *);
          /* next 4 return -1 on error */
  int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
  int DSA_sign(int type, const unsigned char *dgst, int dlen,
               unsigned char *sig, unsigned int *siglen, DSA *dsa);
  int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
                 const unsigned char *sigbuf, int siglen, DSA *dsa);
  int DSA_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
                           CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func);
  int DSA_set_ex_data(DSA *d, int idx, void *arg);
  void *DSA_get_ex_data(DSA *d, int idx);
  
  DSA *d2i_DSAPublicKey(DSA **a, const unsigned char **pp, long length);
  DSA *d2i_DSAPrivateKey(DSA **a, const unsigned char **pp, long length);
  DSA *d2i_DSAparams(DSA **a, const unsigned char **pp, long length);
  
  /* Deprecated version */
  # ifndef OPENSSL_NO_DEPRECATED
  DSA *DSA_generate_parameters(int bits,
                               unsigned char *seed, int seed_len,
                               int *counter_ret, unsigned long *h_ret, void
                                (*callback) (int, int, void *), void *cb_arg);
  # endif                         /* !defined(OPENSSL_NO_DEPRECATED) */
  
  /* New version */
  int DSA_generate_parameters_ex(DSA *dsa, int bits,
                                 const unsigned char *seed, int seed_len,
                                 int *counter_ret, unsigned long *h_ret,
                                 BN_GENCB *cb);
  
  int DSA_generate_key(DSA *a);
  int i2d_DSAPublicKey(const DSA *a, unsigned char **pp);
  int i2d_DSAPrivateKey(const DSA *a, unsigned char **pp);
  int i2d_DSAparams(const DSA *a, unsigned char **pp);
  
  # ifndef OPENSSL_NO_BIO
  int DSAparams_print(BIO *bp, const DSA *x);
  int DSA_print(BIO *bp, const DSA *x, int off);
  # endif
  # ifndef OPENSSL_NO_FP_API
  int DSAparams_print_fp(FILE *fp, const DSA *x);
  int DSA_print_fp(FILE *bp, const DSA *x, int off);
  # endif
  
  # define DSS_prime_checks 50
  /*
   * Primality test according to FIPS PUB 186[-1], Appendix 2.1: 50 rounds of
   * Rabin-Miller
   */
  # define DSA_is_prime(n, callback, cb_arg) \
          BN_is_prime(n, DSS_prime_checks, callback, NULL, cb_arg)
  
  # ifndef OPENSSL_NO_DH
  /*
   * Convert DSA structure (key or just parameters) into DH structure (be
   * careful to avoid small subgroup attacks when using this!)
   */
  DH *DSA_dup_DH(const DSA *r);
  # endif
  
  # define EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, nbits) \
          EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DSA, EVP_PKEY_OP_PARAMGEN, \
                                  EVP_PKEY_CTRL_DSA_PARAMGEN_BITS, nbits, NULL)
  
  # define EVP_PKEY_CTRL_DSA_PARAMGEN_BITS         (EVP_PKEY_ALG_CTRL + 1)
  # define EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS       (EVP_PKEY_ALG_CTRL + 2)
  # define EVP_PKEY_CTRL_DSA_PARAMGEN_MD           (EVP_PKEY_ALG_CTRL + 3)
  
  /* BEGIN ERROR CODES */
  /*
   * The following lines are auto generated by the script mkerr.pl. Any changes
   * made after this point may be overwritten when the script is next run.
   */
  void ERR_load_DSA_strings(void);
  
  /* Error codes for the DSA functions. */
  
  /* Function codes. */
  # define DSA_F_D2I_DSA_SIG                                110
  # define DSA_F_DO_DSA_PRINT                               104
  # define DSA_F_DSAPARAMS_PRINT                            100
  # define DSA_F_DSAPARAMS_PRINT_FP                         101
  # define DSA_F_DSA_BUILTIN_PARAMGEN2                      126
  # define DSA_F_DSA_DO_SIGN                                112
  # define DSA_F_DSA_DO_VERIFY                              113
  # define DSA_F_DSA_GENERATE_KEY                           124
  # define DSA_F_DSA_GENERATE_PARAMETERS_EX                 123
  # define DSA_F_DSA_NEW_METHOD                             103
  # define DSA_F_DSA_PARAM_DECODE                           119
  # define DSA_F_DSA_PRINT_FP                               105
  # define DSA_F_DSA_PRIV_DECODE                            115
  # define DSA_F_DSA_PRIV_ENCODE                            116
  # define DSA_F_DSA_PUB_DECODE                             117
  # define DSA_F_DSA_PUB_ENCODE                             118
  # define DSA_F_DSA_SIGN                                   106
  # define DSA_F_DSA_SIGN_SETUP                             107
  # define DSA_F_DSA_SIG_NEW                                109
  # define DSA_F_DSA_SIG_PRINT                              125
  # define DSA_F_DSA_VERIFY                                 108
  # define DSA_F_I2D_DSA_SIG                                111
  # define DSA_F_OLD_DSA_PRIV_DECODE                        122
  # define DSA_F_PKEY_DSA_CTRL                              120
  # define DSA_F_PKEY_DSA_KEYGEN                            121
  # define DSA_F_SIG_CB                                     114
  
  /* Reason codes. */
  # define DSA_R_BAD_Q_VALUE                                102
  # define DSA_R_BN_DECODE_ERROR                            108
  # define DSA_R_BN_ERROR                                   109
  # define DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE                100
  # define DSA_R_DECODE_ERROR                               104
  # define DSA_R_INVALID_DIGEST_TYPE                        106
  # define DSA_R_INVALID_PARAMETERS                         112
  # define DSA_R_MISSING_PARAMETERS                         101
  # define DSA_R_MODULUS_TOO_LARGE                          103
  # define DSA_R_NEED_NEW_SETUP_VALUES                      110
  # define DSA_R_NON_FIPS_DSA_METHOD                        111
  # define DSA_R_NO_PARAMETERS_SET                          107
  # define DSA_R_PARAMETER_ENCODING_ERROR                   105
  # define DSA_R_Q_NOT_PRIME                                113
  
  #ifdef  __cplusplus
  }
  #endif
  #endif
  