

#define OPENSSL_SUPPRESS_DEPRECATED

#include <stdio.h>
#include <openssl/bn.h>
#include "bn_local.h"





static int bn_x931_derive_pi(BIGNUM *pi, const BIGNUM *Xpi, BN_CTX *ctx,
                             BN_GENCB *cb)
{
    int i = 0, is_prime;
    if (!BN_copy(pi, Xpi))
        return 0;
    if (!BN_is_odd(pi) && !BN_add_word(pi, 1))
        return 0;
    for (;;) {
        i++;
        BN_GENCB_call(cb, 0, i);
        
        is_prime = BN_check_prime(pi, ctx, cb);
        if (is_prime < 0)
            return 0;
        if (is_prime)
            break;
        if (!BN_add_word(pi, 2))
            return 0;
    }
    BN_GENCB_call(cb, 2, i);
    return 1;
}



int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
                            const BIGNUM *Xp, const BIGNUM *Xp1,
                            const BIGNUM *Xp2, const BIGNUM *e, BN_CTX *ctx,
                            BN_GENCB *cb)
{
    int ret = 0;

    BIGNUM *t, *p1p2, *pm1;

    
    if (!BN_is_odd(e))
        return 0;

    BN_CTX_start(ctx);
    if (p1 == NULL)
        p1 = BN_CTX_get(ctx);

    if (p2 == NULL)
        p2 = BN_CTX_get(ctx);

    t = BN_CTX_get(ctx);

    p1p2 = BN_CTX_get(ctx);

    pm1 = BN_CTX_get(ctx);

    if (pm1 == NULL)
        goto err;

    if (!bn_x931_derive_pi(p1, Xp1, ctx, cb))
        goto err;

    if (!bn_x931_derive_pi(p2, Xp2, ctx, cb))
        goto err;

    if (!BN_mul(p1p2, p1, p2, ctx))
        goto err;

    

    if (!BN_mod_inverse(p, p2, p1, ctx))
        goto err;

    if (!BN_mul(p, p, p2, ctx))
        goto err;

    if (!BN_mod_inverse(t, p1, p2, ctx))
        goto err;

    if (!BN_mul(t, t, p1, ctx))
        goto err;

    if (!BN_sub(p, p, t))
        goto err;

    if (p->neg && !BN_add(p, p, p1p2))
        goto err;

    

    if (!BN_mod_sub(p, p, Xp, p1p2, ctx))
        goto err;

    if (!BN_add(p, p, Xp))
        goto err;

    

    for (;;) {
        int i = 1;
        BN_GENCB_call(cb, 0, i++);
        if (!BN_copy(pm1, p))
            goto err;
        if (!BN_sub_word(pm1, 1))
            goto err;
        if (!BN_gcd(t, pm1, e, ctx))
            goto err;
        if (BN_is_one(t)) {
            
            int r = BN_check_prime(p, ctx, cb);
            if (r < 0)
                goto err;
            if (r)
                break;
        }
        if (!BN_add(p, p, p1p2))
            goto err;
    }

    BN_GENCB_call(cb, 3, 0);

    ret = 1;

 err:

    BN_CTX_end(ctx);

    return ret;
}



int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx)
{
    BIGNUM *t;
    int i;
    
    if ((nbits < 1024) || (nbits & 0xff))
        return 0;
    nbits >>= 1;
    
    if (!BN_priv_rand_ex(Xp, nbits, BN_RAND_TOP_TWO, BN_RAND_BOTTOM_ANY, 0,
                         ctx))
        return 0;

    BN_CTX_start(ctx);
    t = BN_CTX_get(ctx);
    if (t == NULL)
        goto err;

    for (i = 0; i < 1000; i++) {
        if (!BN_priv_rand_ex(Xq, nbits, BN_RAND_TOP_TWO, BN_RAND_BOTTOM_ANY, 0,
                             ctx))
            goto err;

        
        if (!BN_sub(t, Xp, Xq))
            goto err;
        if (BN_num_bits(t) > (nbits - 100))
            break;
    }

    BN_CTX_end(ctx);

    if (i < 1000)
        return 1;

    return 0;

 err:
    BN_CTX_end(ctx);
    return 0;
}



int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
                              BIGNUM *Xp1, BIGNUM *Xp2,
                              const BIGNUM *Xp,
                              const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb)
{
    int ret = 0;

    BN_CTX_start(ctx);
    if (Xp1 == NULL)
        Xp1 = BN_CTX_get(ctx);
    if (Xp2 == NULL)
        Xp2 = BN_CTX_get(ctx);
    if (Xp1 == NULL || Xp2 == NULL)
        goto error;

    if (!BN_priv_rand_ex(Xp1, 101, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY, 0, ctx))
        goto error;
    if (!BN_priv_rand_ex(Xp2, 101, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY, 0, ctx))
        goto error;
    if (!BN_X931_derive_prime_ex(p, p1, p2, Xp, Xp1, Xp2, e, ctx, cb))
        goto error;

    ret = 1;

 error:
    BN_CTX_end(ctx);

    return ret;

}
