/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "SecureRandom.h"

#include <decaf/lang/exceptions/NullPointerException.h>
#include <decaf/lang/exceptions/IllegalArgumentException.h>

#ifdef HAVE_PTHREAD_H
#include <decaf/internal/security/unix/SecureRandomImpl.h>
#else
#include <decaf/internal/security/windows/SecureRandomImpl.h>
#endif

using namespace decaf;
using namespace decaf::lang;
using namespace decaf::lang::exceptions;
using namespace decaf::security;
using namespace decaf::internal;
using namespace decaf::internal::security;

////////////////////////////////////////////////////////////////////////////////
SecureRandom::SecureRandom() : secureRandom(new SecureRandomImpl()) {
}

////////////////////////////////////////////////////////////////////////////////
SecureRandom::SecureRandom( const std::vector<unsigned char>& seed ) :
    secureRandom(new SecureRandomImpl()) {

    if( !seed.empty() ) {
        this->secureRandom->providerSetSeed( &seed[0], (int)seed.size() );
    }
}

////////////////////////////////////////////////////////////////////////////////
SecureRandom::SecureRandom(const unsigned char* seed, int size) :
    secureRandom(new SecureRandomImpl()) {

    if (seed == NULL) {
        throw NullPointerException( __FILE__, __LINE__, "Seed buffer pointer passed was NULL");
    }

    if (size < 0) {
        throw IllegalArgumentException( __FILE__, __LINE__, "Passed buffer size was negative.");
    }

    if (size > 0) {
        this->secureRandom->providerSetSeed(seed, size);
    }
}

////////////////////////////////////////////////////////////////////////////////
SecureRandom::~SecureRandom() {
}

////////////////////////////////////////////////////////////////////////////////
void SecureRandom::nextBytes(std::vector<unsigned char>& buf) {
    if (!buf.empty()) {
        this->secureRandom->providerNextBytes(&buf[0], (int) buf.size());
    }
}

////////////////////////////////////////////////////////////////////////////////
void SecureRandom::nextBytes(unsigned char* buf, int size) {

    if (buf == NULL) {
        throw NullPointerException( __FILE__, __LINE__, "Buffer pointer passed was NULL");
    }

    if (size < 0) {
        throw IllegalArgumentException( __FILE__, __LINE__, "Passed buffer size was negative.");
    }

    if (size > 0) {
        this->secureRandom->providerNextBytes(buf, size);
    }
}

////////////////////////////////////////////////////////////////////////////////
void SecureRandom::setSeed(unsigned long long seed) {

    if (seed == 0) {
        return;
    }

    unsigned char byteSeed[] = { (unsigned char)( ( seed >> 56 ) & 0xFF ),
                                 (unsigned char)( ( seed >> 48 ) & 0xFF ),
                                 (unsigned char)( ( seed >> 40 ) & 0xFF ),
                                 (unsigned char)( ( seed >> 32 ) & 0xFF ),
                                 (unsigned char)( ( seed >> 24 ) & 0xFF ),
                                 (unsigned char)( ( seed >> 16 ) & 0xFF ),
                                 (unsigned char)( ( seed >> 8 ) & 0xFF ),
                                 (unsigned char)( ( seed ) & 0xFF ) };

    this->secureRandom->providerSetSeed( byteSeed, 8 );
}

////////////////////////////////////////////////////////////////////////////////
void SecureRandom::setSeed(const std::vector<unsigned char>& seed) {
    if (!seed.empty()) {
        this->secureRandom->providerSetSeed(&seed[0], (int) seed.size());
    }
}

////////////////////////////////////////////////////////////////////////////////
void SecureRandom::setSeed(const unsigned char* seed, int size) {

    if (seed == NULL) {
        throw NullPointerException( __FILE__, __LINE__, "Buffer pointer passed was NULL");
    }

    if (size < 0) {
        throw IllegalArgumentException( __FILE__, __LINE__, "Passed buffer size was negative.");
    }

    if (size > 0) {
        this->secureRandom->providerSetSeed(seed, size);
    }
}

////////////////////////////////////////////////////////////////////////////////
int SecureRandom::next(int numBits) {

    if (numBits < 0) {
        numBits = 0;
    } else if (numBits > 32) {
        numBits = 32;
    }

    int bytes = (numBits + 7) / 8;
    unsigned char* next = new unsigned char[bytes];
    unsigned int ret = 0;

    this->nextBytes(next, bytes);
    for (int i = 0; i < bytes; i++) {
        ret = (next[i] & 0xFF) | (ret << 8);
    }

    ret = ret >> ((bytes * 8) - numBits);

    delete[] next;

    return ret;
}