/* 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
/*
 * 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 *freefunc);
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

#if OPENSSL_API_COMPAT >= 0x10100000L
static inline void
DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **r, const BIGNUM **s)
{
	if (r)
		*r = sig->r;
	if (s)
		*s = sig->s;
}

static inline int
DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s)
{
	if (r) {
		BN_free(r);
		sig->r = r;
	}
	if (s) {
		BN_free(s);
		sig->s = s;
	}
	return 1;
}

static inline void DSA_get0_pqg(const DSA *d, const BIGNUM **p,
    const BIGNUM **q, const BIGNUM **g)
{   
	if (p)
		*p = d->p;
	if (q)
		*q = d->q;
	if (g)
		*g = d->g;
}   


static inline int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
{           
	if (p) { 
		BN_free(d->p);
		d->p = p;
	}
	if (q) {
		BN_free(d->q);
		d->q = q;
	}
	if (g) {
		BN_free(d->g);
		d->g = g;
	}
	return 1;
}

static inline void DSA_get0_key(const DSA *d, const BIGNUM **pub_key,
     const BIGNUM **priv_key)
{
	if (pub_key)
	    *pub_key = d->pub_key;
	if (priv_key)  
	    *priv_key = d->priv_key;
}

static inline int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
{
	if (pub_key) {
		BN_free(d->pub_key);
		d->pub_key = pub_key;
	}
	if (priv_key) {
		BN_free(d->priv_key);
		d->priv_key = priv_key;
	}   

	return 1;
}

static inline int DSA_bits(const DSA *d)
{
	return BN_num_bits(d->p);
}
#endif


#ifdef  __cplusplus
}
#endif
#endif
