void bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp)
{
    int i, j, max;
    const BN_ULONG *ap;
    BN_ULONG *rp;
    max = n * 2;
    ap = a;
    rp = r;
    rp[0] = rp[max - 1] = 0;
    rp++;
    j = n;
    if (--j > 0) {
        ap++;
        rp[j] = bn_mul_words(rp, ap, j, ap[-1]);
        rp += 2;
    }
    for (i = n - 2; i > 0; i--) {
        j--;
        ap++;
        rp[j] = bn_mul_add_words(rp, ap, j, ap[-1]);
        rp += 2;
    }
    bn_add_words(r, r, r, max);
    bn_sqr_words(tmp, a, n);
    bn_add_words(r, r, tmp, max);
}
['static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)\n{\n    BIGNUM *kinv = NULL;\n    BIGNUM *m;\n    BIGNUM *xr;\n    BN_CTX *ctx = NULL;\n    int reason = ERR_R_BN_LIB;\n    DSA_SIG *ret = NULL;\n    int rv = 0;\n    m = BN_new();\n    xr = BN_new();\n    if (m == NULL || xr == NULL)\n        goto err;\n    if (!dsa->p || !dsa->q || !dsa->g) {\n        reason = DSA_R_MISSING_PARAMETERS;\n        goto err;\n    }\n    ret = DSA_SIG_new();\n    if (ret == NULL)\n        goto err;\n    ret->r = BN_new();\n    ret->s = BN_new();\n    if (ret->r == NULL || ret->s == NULL)\n        goto err;\n    ctx = BN_CTX_new();\n    if (ctx == NULL)\n        goto err;\n redo:\n    if (!dsa_sign_setup(dsa, ctx, &kinv, &ret->r, dgst, dlen))\n        goto err;\n    if (dlen > BN_num_bytes(dsa->q))\n        dlen = BN_num_bytes(dsa->q);\n    if (BN_bin2bn(dgst, dlen, m) == NULL)\n        goto err;\n    if (!BN_mod_mul(xr, dsa->priv_key, ret->r, dsa->q, ctx))\n        goto err;\n    if (!BN_add(ret->s, xr, m))\n        goto err;\n    if (BN_cmp(ret->s, dsa->q) > 0)\n        if (!BN_sub(ret->s, ret->s, dsa->q))\n            goto err;\n    if (!BN_mod_mul(ret->s, ret->s, kinv, dsa->q, ctx))\n        goto err;\n    if (BN_is_zero(ret->r) || BN_is_zero(ret->s))\n        goto redo;\n    rv = 1;\n err:\n    if (rv == 0) {\n        DSAerr(DSA_F_DSA_DO_SIGN, reason);\n        DSA_SIG_free(ret);\n        ret = NULL;\n    }\n    BN_CTX_free(ctx);\n    BN_clear_free(m);\n    BN_clear_free(xr);\n    BN_clear_free(kinv);\n    return ret;\n}', 'static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,\n                          BIGNUM **kinvp, BIGNUM **rp,\n                          const unsigned char *dgst, int dlen)\n{\n    BN_CTX *ctx = NULL;\n    BIGNUM *k, *kinv = NULL, *r = *rp;\n    int ret = 0;\n    if (!dsa->p || !dsa->q || !dsa->g) {\n        DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_MISSING_PARAMETERS);\n        return 0;\n    }\n    k = BN_new();\n    if (k == NULL)\n        goto err;\n    if (ctx_in == NULL) {\n        if ((ctx = BN_CTX_new()) == NULL)\n            goto err;\n    } else\n        ctx = ctx_in;\n    do {\n        if (dgst != NULL) {\n            if (!BN_generate_dsa_nonce(k, dsa->q, dsa->priv_key, dgst,\n                                       dlen, ctx))\n                goto err;\n        } else if (!BN_rand_range(k, dsa->q))\n            goto err;\n    } while (BN_is_zero(k));\n    BN_set_flags(k, BN_FLG_CONSTTIME);\n    if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {\n        if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,\n                                    dsa->lock, dsa->p, ctx))\n            goto err;\n    }\n    if (!BN_add(k, k, dsa->q))\n        goto err;\n    if (BN_num_bits(k) <= BN_num_bits(dsa->q)) {\n        if (!BN_add(k, k, dsa->q))\n            goto err;\n    }\n    if ((dsa)->meth->bn_mod_exp != NULL) {\n            if (!dsa->meth->bn_mod_exp(dsa, r, dsa->g, k, dsa->p, ctx,\n                                       dsa->method_mont_p))\n                goto err;\n    } else {\n            if (!BN_mod_exp_mont(r, dsa->g, k, dsa->p, ctx, dsa->method_mont_p))\n                goto err;\n    }\n    if (!BN_mod(r, r, dsa->q, ctx))\n        goto err;\n    if ((kinv = BN_mod_inverse(NULL, k, dsa->q, ctx)) == NULL)\n        goto err;\n    BN_clear_free(*kinvp);\n    *kinvp = kinv;\n    kinv = NULL;\n    ret = 1;\n err:\n    if (!ret)\n        DSAerr(DSA_F_DSA_SIGN_SETUP, ERR_R_BN_LIB);\n    if (ctx != ctx_in)\n        BN_CTX_free(ctx);\n    BN_clear_free(k);\n    return ret;\n}', 'int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,\n               BN_CTX *ctx)\n{\n    BIGNUM *t;\n    int ret = 0;\n    bn_check_top(a);\n    bn_check_top(b);\n    bn_check_top(m);\n    BN_CTX_start(ctx);\n    if ((t = BN_CTX_get(ctx)) == NULL)\n        goto err;\n    if (a == b) {\n        if (!BN_sqr(t, a, ctx))\n            goto err;\n    } else {\n        if (!BN_mul(t, a, b, ctx))\n            goto err;\n    }\n    if (!BN_nnmod(r, t, m, ctx))\n        goto err;\n    bn_check_top(r);\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    return (ret);\n}', 'int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)\n{\n    int max, al;\n    int ret = 0;\n    BIGNUM *tmp, *rr;\n    bn_check_top(a);\n    al = a->top;\n    if (al <= 0) {\n        r->top = 0;\n        r->neg = 0;\n        return 1;\n    }\n    BN_CTX_start(ctx);\n    rr = (a != r) ? r : BN_CTX_get(ctx);\n    tmp = BN_CTX_get(ctx);\n    if (!rr || !tmp)\n        goto err;\n    max = 2 * al;\n    if (bn_wexpand(rr, max) == NULL)\n        goto err;\n    if (al == 4) {\n#ifndef BN_SQR_COMBA\n        BN_ULONG t[8];\n        bn_sqr_normal(rr->d, a->d, 4, t);\n#else\n        bn_sqr_comba4(rr->d, a->d);\n#endif\n    } else if (al == 8) {\n#ifndef BN_SQR_COMBA\n        BN_ULONG t[16];\n        bn_sqr_normal(rr->d, a->d, 8, t);\n#else\n        bn_sqr_comba8(rr->d, a->d);\n#endif\n    } else {\n#if defined(BN_RECURSION)\n        if (al < BN_SQR_RECURSIVE_SIZE_NORMAL) {\n            BN_ULONG t[BN_SQR_RECURSIVE_SIZE_NORMAL * 2];\n            bn_sqr_normal(rr->d, a->d, al, t);\n        } else {\n            int j, k;\n            j = BN_num_bits_word((BN_ULONG)al);\n            j = 1 << (j - 1);\n            k = j + j;\n            if (al == j) {\n                if (bn_wexpand(tmp, k * 2) == NULL)\n                    goto err;\n                bn_sqr_recursive(rr->d, a->d, al, tmp->d);\n            } else {\n                if (bn_wexpand(tmp, max) == NULL)\n                    goto err;\n                bn_sqr_normal(rr->d, a->d, al, tmp->d);\n            }\n        }\n#else\n        if (bn_wexpand(tmp, max) == NULL)\n            goto err;\n        bn_sqr_normal(rr->d, a->d, al, tmp->d);\n#endif\n    }\n    rr->neg = 0;\n    if (a->d[al - 1] == (a->d[al - 1] & BN_MASK2l))\n        rr->top = max - 1;\n    else\n        rr->top = max;\n    if (rr != r)\n        BN_copy(r, rr);\n    ret = 1;\n err:\n    bn_check_top(rr);\n    bn_check_top(tmp);\n    BN_CTX_end(ctx);\n    return (ret);\n}', 'void bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp)\n{\n    int i, j, max;\n    const BN_ULONG *ap;\n    BN_ULONG *rp;\n    max = n * 2;\n    ap = a;\n    rp = r;\n    rp[0] = rp[max - 1] = 0;\n    rp++;\n    j = n;\n    if (--j > 0) {\n        ap++;\n        rp[j] = bn_mul_words(rp, ap, j, ap[-1]);\n        rp += 2;\n    }\n    for (i = n - 2; i > 0; i--) {\n        j--;\n        ap++;\n        rp[j] = bn_mul_add_words(rp, ap, j, ap[-1]);\n        rp += 2;\n    }\n    bn_add_words(r, r, r, max);\n    bn_sqr_words(tmp, a, n);\n    bn_add_words(r, r, tmp, max);\n}']