/*
 * Copyright 2005 The Apache Software Foundation.
 *
 * Licensed 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.
 */

/*
 * XSEC
 *
 * NSSCryptoProvider := Base class to handle NSS
 *
 * Author(s): Milan Tomic
 *
 */

#ifndef NSSCRYPTOPROVIDER_INCLUDE
#define NSSCRYPTOPROVIDER_INCLUDE

#include <xsec/framework/XSECDefs.hpp>
#include <xsec/enc/XSECCryptoProvider.hpp>

#if defined (HAVE_NSS)

#include "nss/pk11func.h"
#include "nss/nss.h"

/**
 * @defgroup nsscrypto NSS Interface
 * @ingroup nsscrypto
 * The NSS crypto provides an experimental inerface to the NSS API.
 */
 
 /*\@{*/

class DSIG_EXPORT NSSCryptoProvider : public XSECCryptoProvider {


public :

	/** @name Constructors and Destructors */
	//@{
	/**
	 * \brief Create a NSS interface layer
	 *
	 * @param dbDir Directory where NSS key database is stored.
	 * Will initialise NSS without DB support if nothing passed in.
   * If you are writing Mozilla/Firefox plugin, you shouldn't
   * use this ctor, because Mozilla/Firefox init NSS. Use empty
   * ctor instead.
	 */
	
	NSSCryptoProvider(const char * dbDir);

  /**
	 * \brief Create a NSS interface layer
	 *
	 * Will not initialise NSS library, user should do that
	 */
	
	NSSCryptoProvider();

	virtual ~NSSCryptoProvider();

	//@}

	/** @name Hashing (Digest) Functions */
	//@{

	/**
	 * \brief Return a SHA1 implementation.
	 *
	 * Call used by the library to obtain a SHA1 object from the 
	 * provider.
	 *
	 * @returns A pointer to an NSS Hash object that implements SHA1
	 * @see NSSCryptoHash
	 */

	virtual XSECCryptoHash * hashSHA1() const;

  /**
	 * \brief Return a SHA1 implementation.
	 *
	 * Call used by the library to obtain a SHA1 object from the 
	 * provider.
	 *
	 * @returns A pointer to an NSS Hash object that implements SHA1
	 * @see NSSCryptoHash
	 */

	virtual XSECCryptoHash * hashSHA(int length = 160) const;

	/**
	 * \brief Return a HMAC SHA1 implementation.
	 *
	 * Call used by the library to obtain a HMAC SHA1 object from the 
	 * provider.  The caller will need to set the key in the hash
	 * object with an XSECCryptoKeyHMAC using NSSCryptoHash::setKey()
	 *
	 * @returns A pointer to a Hash object that implements HMAC-SHA1
	 * @see NSSCryptoHash
	 */

	virtual XSECCryptoHash * hashHMACSHA1() const;

  /**
	 * \brief Return a HMAC SHA1 implementation.
	 *
	 * Call used by the library to obtain a HMAC SHA1 object from the 
	 * provider.  The caller will need to set the key in the hash
	 * object with an XSECCryptoKeyHMAC using NSSCryptoHash::setKey()
	 *
	 * @returns A pointer to a Hash object that implements HMAC-SHA1
	 * @see NSSCryptoHash
	 */

	virtual XSECCryptoHash * hashHMACSHA(int length = 160) const;

	/**
	 * \brief Return a MD5 implementation.
	 *
	 * Call used by the library to obtain a MD5 object from the 
	 * NSS provider.
	 *
	 * @returns A pointer to a Hash object that implements MD5
	 * @see NSSCryptoHash
	 */

	virtual XSECCryptoHash * hashMD5() const;

	/**
	 * \brief Return a HMAC MD5 implementation.
	 *
	 * Call used by the library to obtain a HMAC MD5 object from the 
	 * provider.  The caller will need to set the key in the hash
	 * object with an XSECCryptoKeyHMAC using XSECCryptoHash::setKey()
	 *
	 * @note The use of MD5 is explicitly marked as <b>not recommended</b> 
	 * in the XML Digital Signature standard due to recent advances in
	 * cryptography indicating there <em>may</em> be weaknesses in the 
	 * algorithm.
	 *
	 * @returns A pointer to a Hash object that implements HMAC-MD5
	 * @see NSSCryptoHash
	 */

	virtual XSECCryptoHash * hashHMACMD5() const;

  /**
	 * \brief Return a HMAC key
	 *
	 * Sometimes the library needs to create an HMAC key (notably within
	 * the XKMS utilities).
	 *
	 * This function allows the library to obtain a key that can then have
	 * a value set within it.
	 */

	virtual XSECCryptoKeyHMAC * keyHMAC(void) const;

  /**
	 * \brief Determine whether a given algorithm is supported
	 *
	 * A call that can be used to determine whether a given 
	 * digest algorithm is supported
	 */

	virtual bool algorithmSupported(XSECCryptoHash::HashType alg) const;

	//@}

	/** @name Encoding functions */
	//@{

	/**
	 * \brief Return a Base64 encoder/decoder implementation.
	 *
	 * Call used by the library to obtain a Base64 
	 * encoder/decoder.
	 *
	 * @note NSS do implement Base64, but internal
	 * implementation (XSCrypt) is used instead.
	 *
	 * @returns Pointer to the new Base64 encoder.
	 * @see XSCryptCryptoBase64
	 */

	virtual XSECCryptoBase64 * base64() const;

	//@}

	/** @name Keys and Certificates */
	//@{

	/**
	 * \brief Return a DSA key implementation object.
	 * 
	 * Call used by the library to obtain a DSA key object.
	 *
	 * @returns Pointer to the new DSA key
	 * @see NSSCryptoKeyDSA
	 */

	virtual XSECCryptoKeyDSA * keyDSA() const;

	/**
	 * \brief Return an RSA key implementation object.
	 * 
	 * Call used by the library to obtain an NSS RSA key object.
	 *
	 * @returns Pointer to the new RSA key
	 * @see NSSCryptoKeyRSA
	 */

	virtual XSECCryptoKeyRSA * keyRSA() const;

	/**
	 * \brief Return an X509 implementation object.
	 * 
	 * Call used by the library to obtain an object that can work
	 * with X509 certificates.
	 *
	 * @returns Pointer to the new X509 object
	 * @see NSSCryptoX509
	 */

	virtual XSECCryptoX509 * X509() const;

	/**
	 * \brief Determine whether a given algorithm is supported
	 *
	 * A call that can be used to determine whether a given 
	 * symmetric algorithm is supported
	 */

	virtual bool algorithmSupported(XSECCryptoSymmetricKey::SymmetricKeyType alg) const;

	/**
	 * \brief Return a Symmetric Key implementation object.
	 *
	 * Call used by the library to obtain a bulk encryption
	 * object.
	 *
	 * @returns Pointer to the new SymmetricKey object
	 * @see XSECCryptoSymmetricKey
	 */

	virtual XSECCryptoSymmetricKey * keySymmetric(XSECCryptoSymmetricKey::SymmetricKeyType alg) const;

	/**
	 * \brief Obtain some random octets
	 *
	 * For generation of IVs and the like, the library needs to be able
	 * to obtain "random" octets.  The library uses this call to the 
	 * crypto provider to obtain what it needs.
	 *
	 * @param buffer The buffer to place the random data in
	 * @param numOctets Number of bytes required
	 * @returns Number of bytes obtained.
	 */

	virtual unsigned int getRandom(unsigned char * buffer, unsigned int numOctets) const;

  /**
	 * \brief Translate B64 I2OS integer to a NSS SECItem.
	 *
	 * Decodes a Base64 (ds:CryptoBinary) integer into SECItem.
	 *
	 * @param b64 Base 64 string
	 * @param b64Len Length of base64 string
	 * @param retLen Parameter to hold length of return integer
	 */

	static SECItem * b642SI(const char * b64, unsigned int b64Len);

  /**
	 * \brief Translate a SECItem to a B64 I2OS integer .
	 *
	 * Encodes a SECItem in I2OSP base64 encoded format.
	 *
	 * @param n Buffer holding the SECItem
	 * @param nLen Length of data in buffer
	 * @param retLen Parameter to hold length of return integer
	 * @returns A pointer to a buffer holding the encoded data 
	 * (transfers ownership)
	 */

	static unsigned char * SI2b64(SECItem * n, unsigned int &retLen);

	//@}

	/** @name Information Functions */
	//@{

	/**
	 * \brief Returns a string that identifies the Crypto Provider
	 */

	virtual const XMLCh * getProviderName() const;

	//@}


private:

	void Init(const char * dbDir);
	static int m_initialised;

};

/*\@}*/

#endif /* HAVE_NSS */
#endif /* NSSCRYPTOPROVIDER_INCLUDE */

