bool DecryptSignature( string publicKey, string signature, string & keyDecrypted)
{
    ostringstream  pem;
    pem << "-----BEGIN PUBLIC KEY-----" << endl;
    while (publicKey.length() > 64)
    {
        pem << publicKey.substr(0,64) << endl;
        publicKey.erase(0,64);
    }
    if ( !publicKey.empty() )
    {
        pem << publicKey << endl;
    }
    pem << "-----END PUBLIC KEY-----" << endl;

    RSA* rsa= CreateRSAPubKey(pem.str().c_str() );
    if ( rsa == NULL )
    {
        return false;
    }

    char *buffer;
    uint32 len;

    Base64Decode(signature, &buffer, &len );
    int32 decryptedLen=RSA_size(rsa);
    unsigned char decrypted[decryptedLen+1];
    int  retlen = RSA_public_decrypt(len, (unsigned char*)buffer,decrypted,rsa, RSA_PKCS1_PADDING) ;

    RSA_free(rsa);
    free(buffer);
    if ( retlen > 0 )
    {
        //lint -e{571} Suspicious cast - decrypted contains ascii bytes representation of hash of signature
        keyDecrypted=string((char*)decrypted, (size_t) retlen );
        return true;
    }
    else
    {
        return false;
    }
}

RSA* CreateRSAPubKey(const char* key)
{
    RSA *rsa = NULL;
    BIO *keybio ;
    keybio = BIO_new_mem_buf((void*)key, -1); // !!!
    if (!keybio)
    {
        return NULL;
    }
    rsa = PEM_read_bio_RSA_PUBKEY(keybio, NULL, NULL, NULL);  // !!!
    if(!rsa )   
    {
        return NULL;
    }
    BIO_free(keybio); // !!!
    return rsa;
}