/*

 * Copyright 2007-2016 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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

 */

#include <openssl/dsa.h>

#include "internal/refcount.h"

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;

    int32_t version;

    BIGNUM *p;

    BIGNUM *q;                  /* == 20 */

    BIGNUM *g;

    BIGNUM *pub_key;            /* y public key */

    BIGNUM *priv_key;           /* x private key */

    int flags;

    /* Normally used to cache montgomery values */

    BN_MONT_CTX *method_mont_p;

    CRYPTO_REF_COUNT references;

    CRYPTO_EX_DATA ex_data;

    const DSA_METHOD *meth;

    /* functional reference if 'meth' is ENGINE-provided */

    ENGINE *engine;

    CRYPTO_RWLOCK *lock;

};

struct DSA_SIG_st {

    BIGNUM *r;

    BIGNUM *s;

};

struct dsa_method {

    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, const BIGNUM *a1,

                        const BIGNUM *p1, const BIGNUM *a2, const BIGNUM *p2,

                        const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont);

    /* Can be null */

    int (*bn_mod_exp) (DSA *dsa, BIGNUM *r, const 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;

    void *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);

};

int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,

                         const EVP_MD *evpmd, const unsigned char *seed_in,

                         size_t seed_len, unsigned char *seed_out,

                         int *counter_ret, unsigned long *h_ret,

                         BN_GENCB *cb);

int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,

                          const EVP_MD *evpmd, const unsigned char *seed_in,

                          size_t seed_len, int idx, unsigned char *seed_out,

                          int *counter_ret, unsigned long *h_ret,

                          BN_GENCB *cb);