static int dsa_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
{
    const unsigned char *p, *pm;
    int pklen, pmlen;
    int ptype;
    void *pval;
    ASN1_STRING *pstr;
    X509_ALGOR *palg;
    ASN1_INTEGER *privkey = NULL;
    BN_CTX *ctx = NULL;

     STACK_OF(ASN1_TYPE) *ndsa = NULL;
     DSA *dsa = NULL;
 
    int ret = 0;

     if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
         return 0;
     X509_ALGOR_get0(NULL, &ptype, &pval, palg);
    if (*p == (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
        ASN1_TYPE *t1, *t2;
        if (!(ndsa = d2i_ASN1_SEQUENCE_ANY(NULL, &p, pklen)))
            goto decerr;
        if (sk_ASN1_TYPE_num(ndsa) != 2)
            goto decerr;
        /*-
         * Handle Two broken types:
         * SEQUENCE {parameters, priv_key}
         * SEQUENCE {pub_key, priv_key}
         */

        t1 = sk_ASN1_TYPE_value(ndsa, 0);
        t2 = sk_ASN1_TYPE_value(ndsa, 1);
        if (t1->type == V_ASN1_SEQUENCE) {
            p8->broken = PKCS8_EMBEDDED_PARAM;
            pval = t1->value.ptr;
        } else if (ptype == V_ASN1_SEQUENCE)
            p8->broken = PKCS8_NS_DB;
        else
            goto decerr;

        if (t2->type != V_ASN1_INTEGER)
            goto decerr;

        privkey = t2->value.integer;
    } else {
        const unsigned char *q = p;
        if (!(privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)))
            goto decerr;
        if (privkey->type == V_ASN1_NEG_INTEGER) {
            p8->broken = PKCS8_NEG_PRIVKEY;
            ASN1_STRING_clear_free(privkey);
            if (!(privkey = d2i_ASN1_UINTEGER(NULL, &q, pklen)))
                goto decerr;
        }
        if (ptype != V_ASN1_SEQUENCE)
            goto decerr;
    }

    pstr = pval;
    pm = pstr->data;
    pmlen = pstr->length;
    if (!(dsa = d2i_DSAparams(NULL, &pm, pmlen)))
        goto decerr;
    /* We have parameters now set private key */
    if (!(dsa->priv_key = ASN1_INTEGER_to_BN(privkey, NULL))) {
        DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_BN_ERROR);
        goto dsaerr;
    }
    /* Calculate public key */
    if (!(dsa->pub_key = BN_new())) {
        DSAerr(DSA_F_DSA_PRIV_DECODE, ERR_R_MALLOC_FAILURE);
        goto dsaerr;
    }
    if (!(ctx = BN_CTX_new())) {
        DSAerr(DSA_F_DSA_PRIV_DECODE, ERR_R_MALLOC_FAILURE);
        goto dsaerr;
    }

    if (!BN_mod_exp(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p, ctx)) {
        DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_BN_ERROR);
        goto dsaerr;
    }

     }

Unknown