/* $OpenBSD: dsa.h,v 1.30 2018/03/17 15:19:12 tb Exp $ */
/* 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/opensslconf.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

/* 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);
	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;
	};

DSA *d2i_DSAparams_bio(BIO *bp, DSA **a);
int i2d_DSAparams_bio(BIO *bp, DSA *a);
DSA *d2i_DSAparams_fp(FILE *fp, DSA **a);
int i2d_DSAparams_fp(FILE *fp, DSA *a);

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);
void	DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps);
int	DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s);

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);
int i2d_DSAPublicKey(const DSA *a, unsigned char **pp);
extern const ASN1_ITEM DSAPublicKey_it;

DSA *d2i_DSAPrivateKey(DSA **a, const unsigned char **pp, long length);
int i2d_DSAPrivateKey(const DSA *a, unsigned char **pp);
extern const ASN1_ITEM DSAPrivateKey_it;

DSA *d2i_DSAparams(DSA **a, const unsigned char **pp, long length);
int i2d_DSAparams(const DSA *a,unsigned char **pp);
extern const ASN1_ITEM DSAparams_it;

/* 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);

#ifndef OPENSSL_NO_BIO
int	DSAparams_print(BIO *bp, const DSA *x);
int	DSA_print(BIO *bp, const DSA *x, int off);
#endif
int	DSAparams_print_fp(FILE *fp, const DSA *x);
int	DSA_print_fp(FILE *bp, const DSA *x, int off);

#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

void DSA_get0_pqg(const DSA *d, const BIGNUM **p, const BIGNUM **q,
    const BIGNUM **g);
int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g);
void DSA_get0_key(const DSA *d, const BIGNUM **pub_key, const BIGNUM **priv_key);
int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key);
void DSA_clear_flags(DSA *d, int flags);
int DSA_test_flags(const DSA *d, int flags);
void DSA_set_flags(DSA *d, int flags);
ENGINE *DSA_get0_engine(DSA *d);

DSA_METHOD *DSA_meth_new(const char *name, int flags);
void DSA_meth_free(DSA_METHOD *meth);
DSA_METHOD *DSA_meth_dup(const DSA_METHOD *meth);
int DSA_meth_set_sign(DSA_METHOD *meth,
    DSA_SIG *(*sign)(const unsigned char *, int, DSA *));
int DSA_meth_set_finish(DSA_METHOD *meth, int (*finish)(DSA *));

#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_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_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

#ifdef  __cplusplus
}
#endif
#endif
