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 <openssl/e_os2.h>
  
  #ifdef OPENSSL_NO_DSA
  #error DSA is disabled.
  #endif
  
  #ifndef OPENSSL_NO_BIO
  #include <openssl/bio.h>
  #endif
  #include <openssl/crypto.h>
  #include <openssl/ossl_typ.h>
  
  #ifndef OPENSSL_NO_DEPRECATED
  #include <openssl/bn.h>
  #ifndef OPENSSL_NO_DH
  # include <openssl/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
  #define DSA_FLAG_NO_EXP_CONSTTIME       0x02 /* 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.
                                                */
  
  #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);
  	int (*bn_mod_exp)(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
  				const BIGNUM *m, BN_CTX *ctx,
  				BN_MONT_CTX *m_ctx); /* Can be null */
  	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(TINYCLR_SSL_FILE *fp, const DSA *x);
  int	DSA_print_fp(TINYCLR_SSL_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_DO_SIGN				 112
  #define DSA_F_DSA_DO_VERIFY				 113
  #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_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_MISSING_PARAMETERS			 101
  #define DSA_R_MODULUS_TOO_LARGE				 103
  #define DSA_R_NO_PARAMETERS_SET				 107
  #define DSA_R_PARAMETER_ENCODING_ERROR			 105
  
  #ifdef  __cplusplus
  }
  #endif
  #endif
  